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Introduction: Food insecurity is a common problem with many associated negative downstream health impacts. Despite government sponsored and private supports, many individuals struggle with making healthy, nutritious meals. Penn State's Cooking with the Community program was constructed with the objective of providing cooking equipment and instructions to increase knowledge of healthy cooking techniques and consumption of under-utilized food pantry ingredients. Methods: Four cooking demonstrations were held over an 8-month study period in 2021 designed to educate participants on under-utilized and seasonally available ingredients. Each demonstration was professionally led by a chef who taught cooking skills and the use of different equipment, which were subsequently gifted to the participants. Participants were surveyed before and after each demonstration to assess cooking perceptions and comfort using Likert scales. Final analysis was completed in 2022 using mixed effects models to analyze changes between pre- and post-demonstration. Results: There were 34 total participants. Statistically significant improvements were seen in confidence in cooking (mean increase=0.5; SD=0.2; p=0.031; 95% CI=0.1, 1.0), preparation of a simple recipe (mean increase=0.6; SD=0.2; p=0.013; 95% CI=0.1, 1.0), and cooking new foods (mean increase=0.6; SD=0.3; p=0.026; 95% CI=0.1, 1.1). Conclusions: Cooking with the Community provides valuable information on how cooking confidence may be boosted within vulnerable populations by providing cooking equipment and professional instructions on its use.

BACKGROUND:Postoperative delirium occurs frequently in elderly hip fracture surgery patients and is associated with poorer overall outcomes. Because xenon anaesthesia has neuroprotective properties, we evaluated its effect on the incidence of delirium and other outcomes after hip fracture surgery. METHODS:This was a phase II, multicentre, randomized, double-blind, parallel-group, controlled clinical trial conducted in hospitals in six European countries (September 2010 to October 2014). Elderly (≥75yr-old) and mentally functional hip fracture patients were randomly assigned 1:1 to receive either xenon- or sevoflurane-based general anaesthesia during surgery. The primary outcome was postoperative delirium diagnosed through postoperative day 4. Secondary outcomes were delirium diagnosed anytime after surgery, postoperative sequential organ failure assessment (SOFA) scores, and adverse events (AEs). RESULTS:Of 256 enrolled patients, 124 were treated with xenon and 132 with sevoflurane. The incidence of delirium with xenon (9.7% [95% CI: 4.5 -14.9]) or with sevoflurane (13.6% [95% CI: 7.8 -19.5]) were not significantly different (P=0.33). Overall SOFA scores were significantly lower with xenon (least-squares mean difference: -0.33 [95% CI: -0.60 to -0.06]; P=0.017). For xenon and sevoflurane, the incidence of serious AEs and fatal AEs was 8.0% vs 15.9% (P=0.05) and 0% vs 3.8% (P=0.06), respectively. CONCLUSIONS:Xenon anaesthesia did not significantly reduce the incidence of postoperative delirium after hip fracture surgery. Nevertheless, exploratory observations concerning postoperative SOFA-scores, serious AEs, and deaths warrant further study of the potential benefits of xenon anaesthesia in elderly hip fracture surgery patients. CLINICAL TRIAL REGISTRATION:EudraCT 2009-017153-35; ClinicalTrials.gov NCT01199276.

Background: Long-term pulmonary complications have been reported after a coronavirus disease-2019 (COVID-19). We hypothesized that a history of COVID-19 is associated with a measurable decrease in baseline respiratory system compliance in patients undergoing general anesthesia., Methods: In this hospital registry study, we included adult patients undergoing general anesthesia between January 2020 and March 2022 at a tertiary health care network in Massachusetts. We excluded patients with an American Society of Anesthesiologists physical status >IV, laryngoscopic surgeries, and patients who arrived intubated. The primary exposure was a history of COVID-19. The primary outcome was baseline respiratory system compliance (mL/cmH 2 O). Effects of severity of infection, surges (Alpha 1 , Alpha 2 , Delta, and Omicron), patient demographics, and time between infection and assessment of compliance were investigated., Results: A total of 19,921 patients were included. Approximately 1386 (7.0%) patients had a history of COVID-19. A history of COVID-19 at any time before surgery was associated with a measurably lower baseline respiratory system compliance (ratio of means adj = 0.96; 95% confidence interval [CI], 0.94-0.97; P < .001; adjusted compliance difference: -1.6 mL/cmH 2 O). The association was more pronounced in patients with a severe form of COVID-19 (ratio of means adj = 0.95; 95% CI, 0.90-0.99; P = .02, adjusted compliance difference: -2 mL/cmH 2 O). Alpha 1 , Alpha 2 , and Delta surges, but not Omicron, led to a lower baseline respiratory system compliance ( P < .001, P = .02, and P < .001). The Delta surge effect was magnified in Hispanic ethnicity ( P -for-interaction = 0.003; ratio of means adj = 0.83; 95% CI, 0.74-0.93; P = .001; adjusted compliance difference: -4.6 mL/cmH 2 O)., Conclusions: A history of COVID-19 infection during Alpha 1 , Alpha 2 , and Delta surges was associated with a measurably lower baseline respiratory system compliance., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2024 International Anesthesia Research Society.)

Study Objective: A low dynamic driving pressure during mechanical ventilation for general anesthesia has been associated with a lower risk of postoperative respiratory complications (PRC), a key driver of healthcare costs. It is, however, unclear whether maintaining low driving pressure is clinically relevant to measure and contain costs. We hypothesized that a lower dynamic driving pressure is associated with lower costs., Design: Multicenter retrospective cohort study., Setting: Two academic healthcare networks in New York and Massachusetts, USA., Patients: 46,715 adult surgical patients undergoing general anesthesia for non-ambulatory (inpatient and same-day admission) surgery between 2016 and 2021., Interventions: The primary exposure was the median intraoperative dynamic driving pressure., Measurements: The primary outcome was direct perioperative healthcare-associated costs, which were matched with data from the Healthcare Cost and Utilization Project-National Inpatient Sample (HCUP-NIS) to report absolute differences in total costs in United States Dollars (US$). We assessed effect modification by patients' baseline risk of PRC (score for prediction of postoperative respiratory complications [SPORC] ≥ 7) and effect mediation by rates of PRC (including post-extubation saturation < 90%, re-intubation or non-invasive ventilation within 7 days) and other major complications., Main Results: The median intraoperative dynamic driving pressure was 17.2cmH 2 O (IQR 14.0-21.3cmH 2 O). In adjusted analyses, every 5cmH 2 O reduction in dynamic driving pressure was associated with a decrease of -0.7% in direct perioperative healthcare-associated costs (95%CI -1.3 to -0.1%; p = 0.020). When a dynamic driving pressure below 15cmH 2 O was maintained, -US$340 lower total perioperative healthcare-associated costs were observed (95%CI -US$546 to -US$132; p = 0.001). This association was limited to patients at high baseline risk of PRC (n = 4059; -US$1755;97.5%CI -US$2495 to -US$986; p < 0.001), where lower risks of PRC and other major complications mediated 10.7% and 7.2% of this association (p < 0.001 and p = 0.015, respectively)., Conclusions: Intraoperative mechanical ventilation targeting low dynamic driving pressures could be a relevant measure to reduce perioperative healthcare-associated costs in high-risk patients., Competing Interests: Declaration of competing interest Daniel Talmor received speaking fees and grant funds from Hamilton Medical, Inc. and Mindray Medical, outside the submitted work. Matthias Eikermann received grants from Merck & Co and serves as an Associate Editor for the British Journal of Anaesthesia. Maximilian S. Schaefer received funding for investigator-initiated studies from Merck & Co., which do not pertain to this manuscript. He is an associate editor for BMC Anesthesiology. He received honoraria for lectures from Fisher & Paykel Healthcare and Mindray Medical International Limited. He received an unrestricted philanthropic grant from Dr. Jeffrey and Judith Buzen. All other authors have no support from any organization for the submitted work, no financial relationships with any organizations that might have an interest in the submitted work in the previous three years, and no other relationships or activities that could appear to have influenced the submitted work. This work was supported by an unrestricted grant from Dr. Jeffrey and Judith Buzen to Maximilian S. Schaefer. Dr. Jeffrey and Judith Buzen had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication., (Copyright © 2024. Published by Elsevier Inc.)

The role of antithrombotic therapy in the prevention of ischemic stroke after non-cardiac surgery is unclear. In this study, we tested the hypothesis that the association of new-onset postoperative atrial fibrillation (POAF) on ischemic stroke can be mitigated by postoperative oral anticoagulation therapy. Of 251,837 adult patients (155,111 female (61.6%) and 96,726 male (38.4%)) who underwent non-cardiac surgical procedures at two sites, POAF was detected in 4,538 (1.8%) patients. The occurrence of POAF was associated with increased 1-year ischemic stroke risk (3.6% versus 2.3%; adjusted risk ratio (RRadj) = 1.60 (95% confidence interval (CI): 1.37-1.87), P < 0.001). In patients with POAF, the risk of developing stroke attributable to POAF was 1.81 (95% CI: 1.44-2.28; P < 0.001) without oral anticoagulation, whereas, in patients treated with anticoagulation, no significant association was observed between POAF and stroke (RRadj = 1.04 (95% CI: 0.71-1.51), P = 0.847, P for interaction = 0.013). Furthermore, we derived and validated a computational model for the prediction of POAF after non-cardiac surgery based on demographics, comorbidities and procedural risk. These findings suggest that POAF is predictable and associated with an increased risk of postoperative ischemic stroke in patients who do not receive postoperative anticoagulation., Competing Interests: Competing interests M.E. receives funding from the National Institutes of Health (NIH) (R01AG065554 and R01HL132887) that does not pertain to this manuscript. He holds two patents for acyclic curcubiturils for reversal of drugs of abuse and neuromuscular blocking agents (patent numbers 9956229 and 9469648). He is a member of the associated editorial board for the British Journal of Anaesthesia. D.L.B. discloses the following relationships. Advisory Board: Angiowave, Bayer, Boehringer Ingelheim, CellProthera, Cereno Scientific, Elsevier Practice Update Cardiology, High Enroll, Janssen, Level Ex, McKinsey, Medscape Cardiology, Merck, MyoKardia, NirvaMed, Novo Nordisk, PhaseBio, PLx Pharma and Stasys; Board of Directors: American Heart Association New York City, Angiowave (stock options), Bristol Myers Squibb (stock), DRS.LINQ (stock options) and High Enroll (stock); Consultant: Broadview Ventures, Hims, SFJ and Youngene; Data Monitoring Committee: Acesion Pharma, Assistance Publique-Hôpitaux de Paris, Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute, for the PORTICO trial, funded by St. Jude Medical, now Abbott), Boston Scientific (chair, PEITHO trial), Cleveland Clinic, Contego Medical (chair, PERFORMANCE 2), Duke Clinical Research Institute, Mayo Clinic, Mount Sinai School of Medicine (for the ENVISAGE trial, funded by Daiichi Sankyo; for the ABILITY-DM trial, funded by Concept Medical; for ALLAY-HF, funded by Alleviant Medical), Novartis, Population Health Research Institute and Rutgers University (for the NIH-funded MINT Trial); Honoraria: American College of Cardiology (ACC) (senior associate editor, Clinical Trials and News; chair, ACC Accreditation Oversight Committee), Arnold and Porter law firm (work related to Sanofi/Bristol Myers Squibb clopidogrel litigation), Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute; RE-DUAL PCI clinical trial steering committee, funded by Boehringer Ingelheim; AEGIS-II executive committee, funded by CSL Behring), Belvoir Publications (editor in chief, Harvard Heart Letter), Canadian Medical and Surgical Knowledge Translation Research Group (clinical trial steering committees), CSL Behring (American Heart Association lecture), Cowen and Company, Duke Clinical Research Institute (clinical trial steering committees, including for the PRONOUNCE trial, funded by Ferring Pharmaceuticals), HMP Global (editor in chief, Journal of Invasive Cardiology), Journal of the American College of Cardiology (guest editor and associate editor), K2P (co-chair, interdisciplinary curriculum), Level Ex, Medtelligence/ReachMD (CME steering committees), MJH Life Sciences, Oakstone CME (course director, Comprehensive Review of Interventional Cardiology), Piper Sandler, Population Health Research Institute (for the COMPASS operations committee, publications committee and steering committee and USA national co-leader, funded by Bayer), WebMD (CME steering committees) and Wiley (steering committee); Other: Clinical Cardiology (deputy editor); Patent: sotagliflozin (named on a patent for sotagliflozin assigned to Brigham and Women's Hospital, assigned to Lexicon; neither D.L.B. nor Brigham and Women's Hospital receive any income from this patent); Research Funding: Abbott, Acesion Pharma, Afimmune, Aker Biomarine, Alnylam, Amarin, Amgen, AstraZeneca, Bayer, Beren, Boehringer Ingelheim, Boston Scientific, Bristol Myers Squibb, Cardax, CellProthera, Cereno Scientific, Chiesi, CinCor, Cleerly, CSL Behring, Eisai, Ethicon, Faraday Pharmaceuticals, Ferring Pharmaceuticals, Forest Laboratories, Fractyl, Garmin, HLS Therapeutics, Idorsia, Ironwood, Ischemix, Janssen, Javelin, Lexicon, Eli Lilly, Medtronic, Merck, Moderna, MyoKardia, NirvaMed, Novartis, Novo Nordisk, Otsuka, Owkin, Pfizer, PhaseBio, PLx Pharma, Recardio, Regeneron, Reid Hoffman Foundation, Roche, Sanofi, Stasys, Synaptic, The Medicines Company, Youngene and 89Bio; Royalties: Elsevier (editor, Braunwald’s Heart Disease); Site Co-Investigator: Abbott, Biotronik, Boston Scientific, CSI, Endotronix, St. Jude Medical (now Abbott), Philips, SpectraWAVE, Svelte and Vascular Solutions; Trustee: ACC; Unfunded Research: FlowCo. M.S.S. received funding for investigator-initiated studies from Merck & Co., which does not pertain to this manuscript. He is an associate editor for BMC Anesthesiology. He received honoraria for lectures from Fisher & Paykel Healthcare and Mindray Medical International Limited. He received an unrestricted philanthropic grant from Jeff and Judy Buzen. All other authors have no support from any organization for the submitted work, no financial relationships with any organizations that might have an interest in the submitted work and no other relationships or activities that could appear to have influenced the submitted work., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background: Recruitment maneuvers are used in patients with ARDS to enhance oxygenation and lung mechanics. Heterogeneous lung and chest-wall mechanics lead to unpredictable transpulmonary pressures and could impact recruitment maneuver success. Tailoring care based on individualized transpulmonary pressure might optimize recruitment, preventing overdistention. This study aimed to identify the optimal transpulmonary pressure for effective recruitment and to explore its association with baseline characteristics., Methods: We performed post hoc analysis on the Esophageal Pressure Guided Ventilation (EpVent2) trial. We estimated the dose-response relationship between end-recruitment end-inspiratory transpulmonary pressure and the change in lung elastance after a recruitment maneuver by using logistic regression weighted by a generalized propensity score. A positive change in lung elastance was indicative of overdistention. We examined how patient characteristics, disease severity markers, and respiratory parameters predict transpulmonary pressure by using multivariate linear regression models and dominance analyses., Results: Of 121 subjects, 43.8% had a positive change in lung elastance. Subjects with a positive change in lung elastance had a mean ± SD transpulmonary pressure of 15.1 ± 4.9 cm H 2 O, compared with 13.9 ± 3.9 cm H 2 O in those with a negative change in lung elastance. Higher transpulmonary pressure was associated with increased probability of a positive change in lung elastance (adjusted odds ratio 1.35 per 1 cm H 2 O of transpulmonary pressure, 95% CI 1.13-1.61; P = .001), which indicated an S-shaped dose-response curve, with overdistention probability > 50% at transpulmonary pressure values > 18.3 cm H 2 O. The volume of recruitment was transpulmonary pressure-dependent ( P < .001; R 2 = 0.49) and inversely related to a change in lung elastance after adjusting for baseline lung elastance ( P < .001; R 2 = 0.43). Negative correlations were observed between transpulmonary pressure and body mass index, PEEP, Sequential Organ Failure Assessment score, and P aO 2 /F IO 2 , whereas baseline lung elastance showed a positive correlation. The body mass index emerged as the dominant negative predictor of transpulmonary pressure (ranking 1; contribution to R 2 = 0.08), whereas pre-recruitment elastance was the sole positive predictor (contribution to R 2 = 0.06)., Conclusions: Higher end-recruitment transpulmonary pressure increases the volume of recruitment but raises the risk of overdistention, providing the rationale for transpulmonary pressure to be used as a clinical target. Predictors, for example, body mass index, could guide recruitment maneuver individualization to balance adequate volume gain with overdistention., (Copyright © 2024 by Daedalus Enterprises.)

Background: The US Centers for Medicare and Medicaid Services provide guidelines for the coverage of anaesthesia residents and certified registered nurse anaesthetists (CRNAs) by anaesthesiologists. We tested the hypothesis that changes in the anaesthesia staffing model increase billing compliance., Methods: We analysed 13 926 anaesthesia cases performed between September 2019 and November 2019 (baseline), and between September 2020 and November 2020 (after change in staff model) at a US academic medical centre using an estimation tool. The intervention was assignment of additional 12-h weekday CRNAs plus an additional anaesthesiologist who covered weekdays after 17:00, weekends, and holidays. The proportion of cases with billing compliant coverage (covered either by solo anaesthesiologist or anaesthesiologist covering two or fewer residents or four or fewer CRNAs) was analysed using logistic and segmented regression analyses., Results: The change in staff model was associated with a decrease in non-optimal anaesthesia staff assignments from 4.2% to 1.2% of anaesthesia cases (adjusted odds ratio 0.25; 95% confidence interval [CI] 0.20-0.32; P<0.001) and an increase in billable anaesthesia units of 0.6 per anaesthesia case (95% CI 0.4-0.8; P<0.001). An increased revenue margin associated with optimal staffing levels would only be achieved with salary levels at the 25th percentile of relevant benchmark compensation levels. Total staff overtime for all anaesthesia providers decreased (adjusted absolute difference -4.1 total overtime hours per day; 95% CI -7.0 to -1.3; P=0.004)., Conclusions: Implementation of a change in anaesthesia staffing model was associated with improved billing compliance, higher billable anaesthesia units, and reduced overtime. The effects of the anaesthesia staff model on revenue and financial margin can be determined using our web-based margin-cost estimation tool., (Copyright © 2024 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: Previous studies suggested that surgeon sex is associated with differential patient outcomes. Whether this also applies to anaesthesia providers is unclear. We hypothesised that female sex of the primary anaesthesia provider is associated with lower risk of perioperative complications., Methods: The first case for all adult patients undergoing anaesthesia care between 2008 and 2022 at two academic healthcare networks in the USA was included in this retrospective cohort study. The primary exposure was the sex of the anaesthesia provider who spent the most time in the operating theatre during the case. The primary outcome was intraoperative complications, defined as hypotension (mean arterial blood pressure <55 mm Hg for ≥5 cumulative minutes) or hypoxaemia (oxygen saturation <90% for >2 consecutive minutes). The co-primary outcome was 30-day adverse postoperative events (including complications, readmission, and mortality). Analyses were adjusted for a priori defined confounders., Results: Among 364,429 included patients, 57,550 (15.8%) experienced intraoperative complications and 55,168 (15.1%) experienced adverse postoperative events. Care by female compared with male anaesthesia providers was associated with lower risk of intraoperative complications (adjusted odds ratio [aOR] 0.95, 95% confidence interval [CI] 0.94-0.97, P<0.001), which was magnified among non-trainees (aOR 0.84, 95% CI 0.82-0.87, P-for-interaction<0.001). Anaesthesia provider sex was not associated with the composite of adverse postoperative events (aOR 1.00, 95% CI 0.98-1.02, P=0.88)., Conclusions: Care by a female anaesthesia provider was associated with a lower risk of intraoperative complications, which was magnified among non-trainees. Future studies should investigate underlying mechanisms., (Copyright © 2024 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Study Objective: To estimate the incidence of postoperative oxygenation impairment after lung resection in the era of lung-protective management, and to identify perioperative factors associated with that impairment., Design: Registry-based retrospective cohort study., Setting: Two large academic hospitals in the United States., Patients: 3081 ASA I-IV patients undergoing lung resection., Measurements: 79 pre- and intraoperative variables, selected for inclusion based on a causal inference framework. The primary outcome of impaired oxygenation, an early marker of lung injury, was defined as at least one of the following within seven postoperative days: (1) SpO 2  < 92%; (2) imputed PaO 2 /FiO 2  < 300 mmHg [(1) or (2) occurring at least twice within 24 h]; (3) intensive oxygen therapy (mechanical ventilation or > 50% oxygen or high-flow oxygen)., Main Results: Oxygenation was impaired within seven postoperative days in 70.8% of patients (26.6% with PaO 2 /FiO 2  < 200 mmHg or intensive oxygen therapy). In multivariable analysis, each additional cmH 2 O of intraoperative median driving pressure was associated with a 7% higher risk of impaired oxygenation (OR 1.07; 95%CI 1.04 to 1.10). Higher median intraoperative FiO 2 (OR 1.23; 95%CI 1.14 to 1.31 per 0.1) and PEEP (OR 1.12; 95%CI 1.04 to 1.21 per 1 cm H 2 O) were also associated with increased risk. History of COPD (OR 2.55; 95%CI 1.95 to 3.35) and intraoperative albuterol administration (OR 2.07; 95%CI 1.17 to 3.67) also showed reliable effects., Conclusions: Impaired postoperative oxygenation is common after lung resection and is associated with potentially modifiable pre- and intraoperative respiratory factors., Competing Interests: Declaration of competing interest No relevant conflicts of interest to report for any authors., (Copyright © 2023. Published by Elsevier Inc.)

Background: ChatGPT is an AI platform whose relevance in the peer review of scientific articles is steadily growing. Nonetheless, it has sparked debates over its potential biases and inaccuracies. This study aims to assess ChatGPT's ability to qualitatively emulate human reviewers in scientific research., Methods: We included the first submitted version of the latest twenty original research articles published by the 3rd of July 2023, in a high-profile medical journal. Each article underwent evaluation by a minimum of three human reviewers during the initial review stage. Subsequently, three researchers with medical backgrounds and expertise in manuscript revision, independently and qualitatively assessed the agreement between the peer reviews generated by ChatGPT version GPT-4 and the comments provided by human reviewers for these articles. The level of agreement was categorized into complete, partial, none, or contradictory., Results: 720 human reviewers' comments were assessed. There was a good agreement between the three assessors (Overall kappa >0.6). ChatGPT's comments demonstrated complete agreement in terms of quality and substance with 48 (6.7 %) human reviewers' comments, partially agreed with 92 (12.8 %), identifying issues necessitating further elaboration or recommending supplementary steps to address concerns, had no agreement with a significant 565 (78.5 %), and contradicted 15 (2.1 %). ChatGPT comments on methods had the lowest proportion of complete agreement (13 comments, 3.6 %), while general comments on the manuscript displayed the highest proportion of complete agreement (17 comments, 22.1 %)., Conclusion: ChatGPT version GPT-4 has a limited ability to emulate human reviewers within the peer review process of scientific research., Competing Interests: Declaration of competing interest Maximilian S. Schaefer received funding for investigator-initiated studies from Merck & Co., which do not pertain to this manuscript. He is an associate editor for BMC Anesthesiology. He received honoraria for presentations from Fisher & Paykel Healthcare and Mindray Medical International Limited and an unrestricted philantropic grant from Jeffrey and Judith Buzen. All other authors have no conflicts of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Acetaminophen and 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists are administered as standard prophylaxes for postoperative pain, nausea, and vomiting. Preclinical studies, however, suggest that 5-HT3 antagonists may compromise acetaminophen's analgesic effect. This hospital registry study investigates whether 5-HT3 antagonists mitigate the analgesic effect of prophylactic acetaminophen in a perioperative setting., Methods: This study included 55,016 adult patients undergoing general anesthesia for ambulatory procedures at a tertiary healthcare center in Massachusetts from 2015 to 2022. Using binary exposure variables and a comprehensive selection of preplanned patient- and procedure-related covariates for confounder control, the authors investigated whether intraoperative 5-HT3 antagonists affected the association between pre- or intraoperative acetaminophen and postoperative opioid consumption, gauged by opioid dose in milligram oral morphine equivalents (OME) administered in the postanesthesia care unit. A multivariable, zero-inflated negative binomial regression model was applied., Results: A total of 3,166 patients (5.8%) received only acetaminophen, 15,438 (28.1%) only 5-HT3 antagonists, 31,850 (57.9%) both drugs, and 4,562 (8.3%) neither drug. The median postanesthesia care unit opioid dose was 7.5 mg OME (interquartile range, 7.5 to 14.3 mg OME) among 16,640 of 55,016 (30.2%) patients who received opioids, and the mean opioid dose was 3.2 mg OME across all patients (maximum cumulative dose, 20.4 mg OME). Acetaminophen administration was associated with a -5.5% (95% CI, -9.6 to -1.4%; P = 0.009; adjusted absolute difference, -0.19 mg OME; 95% CI, -0.33 to -0.05; P = 0.009) reduction in opioid consumption among patients who did not receive a 5-HT3 antagonist, while there was no effect in patients who received a 5-HT3 antagonist (adjusted absolute difference, 0.00 mg OME; 95% CI, -0.06 to 0.05; P = 0.93; P for interaction = 0.013)., Conclusions: A dose-dependent association of pre- or intraoperative acetaminophen with decreased postoperative opioid consumption was not observed when 5-HT3 antagonists were coadministered, suggesting that physicians might consider reserving 5-HT3 antagonists as rescue medication for postoperative nausea or vomiting when acetaminophen is administered for pain prophylaxis., (Copyright © 2024 American Society of Anesthesiologists. All Rights Reserved.)

According to the US Census, for the first time in history, older adults are projected to exceed the number of children by 2035. These seniors are headed to the outdoors in increasing numbers and face unique risks. They benefit from careful pre-event evaluation planning to maintain their health in wilderness environments. Climate change is affecting all of us, but seniors are considered an especially vulnerable group. This vulnerability needs to be addressed not only when older adults head into the wilderness but also when the wilderness "comes to them" in areas where wilderness medicine and disaster medicine overlap. Education of both providers and patients is vital. This article aims to discuss the special needs of older adults/seniors /elders (defined as those over 65 unless otherwise indicated) in the wilderness as well as the vulnerability of older adults to climate change, both during planned wilderness activities and when the wilderness "comes to them" because of climate change, and to identify opportunities for education and adaptation of patients and education of physicians and wilderness and disaster responders to care for these older patients. The PubMed and Google Scholar Database search engines were utilized to review relevant English language publications between 2000 and 2023 that addressed individuals over 65 and explored the overlap of geriatrics (aged over 65), wilderness and disaster medicine, and climate change and create a perspective summary. Because of increased numbers of older adults heading into the wilderness for outdoor activities or having wilderness thrust upon them due to climate change, cross training of all specialties including the fields of emergency, geriatrics, wilderness medicine, and disaster medicine is needed in collaboration with other organizations and search and rescue. Response agencies must recognize that training in wilderness medicine provides a background for practitioners working in dangerous and remote settings and ought to seek out individuals with such skills when placing responders in the field. Climate change is making these intersections and the need for this education more urgent with time., Competing Interests: Declaration of Conflicting InterestsThe author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study Objective: To investigate post-procedural recovery as well as peri-procedural respiratory and hemodynamic safety parameters with prolonged use of high-frequency jet ventilation (HFJV) versus conventional ventilation in patients undergoing catheter ablation for atrial fibrillation., Design: Hospital registry study., Setting: Tertiary academic teaching hospital in New England., Patients: 1822 patients aged 18 years and older undergoing catheter ablation between January 2013 and June 2020., Interventions: HFJV versus conventional mechanical ventilation., Measurements: The primary outcome was post-anesthesia care unit (PACU) length of stay. In secondary analyses we assessed the effect of HFJV on intra-procedural hypoxemia, defined as the occurrence of peripheral hemoglobin oxygen saturation (SpO 2 ) <90%, post-procedural respiratory complications (PRC) as well as intra-procedural hypocarbia and hypotension. Multivariable negative binomial and logistic regression analyses, adjusted for patient and procedural characteristics, were applied., Main Results: 1157 patients (63%) received HFJV for a median (interquartile range [IQR]) duration of 307 (253-360) minutes. The median (IQR) length of stay in the PACU was 244 (172-370) minutes in patients who underwent ablation with conventional mechanical ventilation and 226 (163-361) minutes in patients receiving HFJV. In adjusted analyses, patients undergoing HFJV had a longer PACU length of stay (adjusted absolute difference: 37.7 min; 95% confidence interval [CI] 9.7-65.8; p = 0.008). There was a higher risk of intra-procedural hypocarbia (adjusted odds ratio [OR adj ] 5.90; 95%CI 2.63-13.23; p < 0.001) and hypotension (OR adj 1.88; 95%CI 1.31-2.72; p = 0.001) in patients undergoing HFJV. No association was found between the use of HFJV and intra-procedural hypoxemia or PRC (p = 0.51, and p = 0.97, respectively)., Conclusion: After confounder adjustment, HFJV for catheter ablation procedures for treatment of atrial fibrillation was associated with a longer length of stay in the PACU. It was further associated with an increased risk of intra-procedural abnormalities including abnormal carbon dioxide homeostasis, as well as intra-procedural arterial hypotension., Competing Interests: Declaration of Competing Interest M.S.S. has received grants for investigator-initiated trials not related to this manuscript from Merck & Co. He has received speaker fees from Mindray Medical International Limited, and from Fisher & Paykel Healthcare. He is an Associate Editor for BMC Anesthesiology and received unrestricted funds from philanthropic donors Jeffrey and Judith Buzen. J.W.W. is on an advisory board for HearCor Solutions and has received research support not related to this study from Anumana. The funders had no role in the design and conduct of the study, the collection, management, analysis, and interpretation of the data, the preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication. R.MA., T.M.T., B.A.A., A.S., E.A., L.J.W., F.C.L., G.C., P.T. and S.S. have no conflicts of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: We investigated the effects of ketamine on desaturation and the risk of nursing home discharge in patients undergoing procedural sedation by anaesthetists., Methods: We included adult patients who underwent procedures under monitored anaesthetic care between 2005 and 2021 at two academic healthcare networks in the USA. The primary outcome was intraprocedural oxygen desaturation, defined as oxygen saturation <90% for ≥2 consecutive minutes. The co-primary outcome was a nursing home discharge., Results: Among 234,170 included patients undergoing procedural sedation, intraprocedural desaturation occurred in 5.6% of patients who received ketamine vs 5.2% of patients who did not receive ketamine (adjusted odds ratio [OR adj ] 1.22, 95% confidence interval [CI] 1.15-1.29, P<0.001; adjusted absolute risk difference [ARD adj ] 1%, 95% CI 0.7-1.3%, P<0.001). The effect was magnified by age >65 yr, smoking, or preprocedural ICU admission (P-for-interaction <0.001, OR adj 1.35, 95% CI 1.25-1.45, P<0.001; ARD adj 2%, 95% CI 1.56-2.49%, P<0.001), procedural risk factors (upper endoscopy of longer than 2 h; P-for-interaction <0.001, OR adj 2.91, 95% CI 1.85-4.58, P<0.001; ARD adj 16.2%, 95% CI 9.8-22.5%, P<0.001), and high ketamine dose (P-for-trend <0.001, OR adj 1.61, 95% CI, 1.43-1.81 for ketamine >0.5 mg kg -1 ). Concomitant opioid administration mitigated the risk (P-for-interaction <0.001). Ketamine was associated with higher odds of nursing home discharge (OR adj 1.11, 95% CI 1.02-1.21, P=0.012; ARD adj 0.25%, 95% CI 0.05-0.46%, P=0.014)., Conclusions: Ketamine use for procedural sedation was associated with an increased risk of oxygen desaturation and discharge to a nursing home. The effect was dose-dependent and magnified in subgroups of vulnerable patients., (Copyright © 2023 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: The treatment of intraoperative hypotension with phenylephrine may impair cerebral perfusion through vasoconstriction, which has been linked to postoperative delirium. The hypothesis was that intraoperative administration of phenylephrine, compared to ephedrine, is associated with higher odds of postoperative delirium., Methods: A total of 103,094 hospitalized adults undergoing general anesthesia for noncardiac, non-neurosurgical procedures between 2008 and 2020 at two tertiary academic healthcare networks in Massachusetts were included in this multicenter hospital registry study. The primary exposure was the administration of phenylephrine versus ephedrine during surgery, and the primary outcome was postoperative delirium within 7 days. Multivariable logistic regression analyses adjusted for a priori defined confounding variables including patient demographics, comorbidities, and procedural factors including magnitude of intraoperative hypotension were applied., Results: Between the two healthcare networks, 78,982 (76.6%) patients received phenylephrine, and 24,112 (23.4%) patients received ephedrine during surgery; 770 patients (0.8%) developed delirium within 7 days. The median (interquartile range) total intraoperative dose of phenylephrine was 1.0 (0.2 to 3.3) mg and 10.0 (10.0 to 20.0) mg for ephedrine. In adjusted analyses, the administration of phenylephrine, compared to ephedrine, was associated with higher odds of developing postoperative delirium within 7 days (adjusted odds ratio, 1.35; 95% CI, 1.06 to 1.71; and adjusted absolute risk difference, 0.2%; 95% CI, 0.1 to 0.3%; P = 0.015). A keyword and manual chart review-based approach in a subset of 45,465 patients further validated these findings (delirium incidence, 3.2%; adjusted odds ratio, 1.88; 95% CI, 1.49 to 2.37; P < 0.001). Fractional polynomial regression analysis further indicated a dose-dependent effect of phenylephrine (adjusted coefficient, 0.08; 95% CI, 0.02 to 0.14; P = 0.013, per each μg/kg increase in the cumulative phenylephrine dose)., Conclusions: The administration of phenylephrine compared to ephedrine during general anesthesia was associated with higher odds of developing postoperative delirium. Based on these data, clinical trials are warranted to determine whether favoring ephedrine over phenylephrine for treatment of intraoperative hypotension can reduce delirium after surgery., (Copyright © 2023 American Society of Anesthesiologists. All Rights Reserved.)

Introduction: Perioperative opioid use has been associated with adverse clinical outcomes. Additionally, opioid disposal carries significant costs, due to the waste of pharmaceutical products and the time needed by skilled labor to report the waste. In this study, we aimed to estimate costs and predict factors of opioid-associated intraoperative product waste, as well as to evaluate whether higher intraoperative opioid doses are associated with increased risk of adverse postoperative outcomes., Methods: We included 170,607 patients undergoing general anesthesia and receiving intraoperative fentanyl, hydromorphone, or morphine at Beth Israel Deaconess Medical Center, Boston, MA, USA, between January 2010 and June 2020. We estimated product waste-associated costs based on various opioid syringe sizes and determined predictors of opioid waste. Further, we evaluated whether higher opioid doses were associated with postoperative adverse events according to the severity-indexed, incident report-based medication error-reporting program classification. The primary outcome included post-extubation desaturation, postoperative nausea or vomiting, or postoperative somnolence or sedation., Results: The use of the smallest syringe sizes (50 mcg for fentanyl, 0.2 mg for hydromorphone, and 2 mg for morphine) resulted in the lowest product waste-associated costs. The main predictor of opioid waste was the administration of more than one intraoperative opioid (adjusted odds ratio [aOR] = 7.64, 95% CI 7.40-7.89, P < 0.001). Intraoperative doses of fentanyl > 50-100 mcg (aOR = 1.17 [1.10-1.25], P < 0.001, adjusted risk difference [ARD] 2%) and > 100 mcg (aOR = 1.24 [1.16-1.33], P < 0.001, ARD 3%), hydromorphone > 1 mg (aOR = 1.13 [1.06-1.20], P < 0.001, ARD 2%), and morphine > 2-4 mg (aOR = 1.26 [1.02-1.56], P = 0.04, ARD 3%) and > 4 mg (aOR = 1.45 [1.18-1.77], P < 0.001, ARD 5%) were associated with higher risk of the primary outcome., Conclusion: Smaller syringe sizes of intraoperative opioids may help to reduce product waste and associated costs, as well postoperative adverse events through utilization of lower intraoperative opioid doses., (© 2024. The Author(s).)

Rationale: Lung-protective mechanical ventilation strategies have been proven beneficial in the operating room (OR) and the ICU. However, differential practices in ventilator management persist, often resulting in adjustments of ventilator parameters when transitioning patients from the OR to the ICU. Objectives: To characterize patterns of ventilator adjustments during the transition of mechanically ventilated surgical patients from the OR to the ICU and assess their impact on 28-day mortality. Methods: Hospital registry study including patients undergoing general anesthesia with continued, controlled mechanical ventilation in the ICU between 2008 and 2022. Ventilator parameters were assessed 1 hour before and 6 hours after the transition. Measurements and Main Results: Of 2,103 patients, 212 (10.1%) died within 28 days. Upon OR-to-ICU transition, V T and driving pressure decreased (-1.1 ml/kg predicted body weight [IQR, -2.0 to -0.2]; P  < 0.001; and -4.3 cm H 2 O [-8.2 to -1.2]; P  < 0.001). Concomitantly, respiratory rates increased (+5.0 breaths/min [2.0 to 7.5]; P  < 0.001), resulting overall in slightly higher mechanical power (MP) in the ICU (+0.7 J/min [-1.9 to 3.0]; P  < 0.001). In adjusted analysis, increases in MP were associated with a higher 28-day mortality rate (adjusted odds ratio, 1.10; 95% confidence interval, 1.06-1.14; P  < 0.001; adjusted risk difference, 0.7%; 95% confidence interval, 0.4-1.0, both per 1 J/min). Conclusion: During transition of mechanically ventilated patients from the OR to the ICU, ventilator adjustments resulting in higher MP were associated with a greater risk of 28-day mortality.

Background: Patients suffering from obstructive sleep apnea (OSA) experience chronic sleep disturbances and desaturation, factors that have been associated with postoperative delirium and that can be aggravated after anesthesia for complex procedures. We investigated whether OSA is associated with delirium after anesthesia, and whether this association is modified by procedural complexity., Methods: Hospitalized patients ≥60 years who underwent general anesthesia or procedural sedation for procedures of moderate-to-high complexity between 2009 and 2020 at a tertiary health care network in Massachusetts were included. The primary exposure was OSA, defined based on International Classification of Diseases ( Ninth/Tenth Revision, Clinical Modification ) ( ICD-9 / 10-CM ) diagnostic codes, structured nursing interviews, anesthesia alert notes, and a validated risk score (BOSTN [body mass index, observed apnea, snoring, tiredness, and neck circumference]). The primary end point was delirium within 7 days after the procedure. Multivariable logistic regression and effect modification analyses adjusted for patient demographics, comorbidities, and procedural factors were applied., Results: A total of 46,352 patients were included, of which 1694 patients (3.7%) developed delirium, 537 (3.2%) with OSA, and 1,157 (4.0%) without OSA. In adjusted analyses, OSA was not associated with postprocedural delirium in the overall cohort (adjusted odds ratio [OR adj ], 1.06; 95% confidence interval [CI], 0.94-1.20; P = .35). However, a high procedural complexity modified the primary association ( P value for interaction = .002). OSA patients had a higher risk of delirium after high-complexity procedures (≥40 work relative value units) such as cardiac (OR adj , 1.33; 95% CI, 1.08-1.64; P = .007, P value for interaction = .005) or thoracic surgery (OR adj , 1.89; 95% CI, 1.19-3.00; P = .007, P value for interaction = .009), but no increased risk after moderate complexity procedures, including general surgery (OR adj , 0.86; 95% CI, 0.55-1.35; P = .52)., Conclusions: Compared to non-OSA patients, a history of OSA is associated with a higher risk after high-complexity procedures such as cardiac or thoracic surgery but not after procedures of moderate complexity., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2023 International Anesthesia Research Society.)

Competing Interests: Drs Baedorf Kassis and Talmor disclose relationships with Hamilton Medical. The remaining authors have disclosed no conflicts of interest.

Background: Reintubation after lung cancer resection is an important quality metric because of increased disability, mortality and cost. However, no validated predictive instrument is in use to reduce reintubation after lung resection. This study aimed to create and validate the PRediction Of REintubation After Lung cancer resection (PROREAL) score., Methods: The study analyzed lung resection cases from 2 university hospitals. The primary end point was reintubation within 7 days after surgery. Predictors were selected through backward stepwise logistic regression and bootstrap resampling. The investigators used reclassification and receiver-operating characteristic (ROC) curve analyses to assess score performance and compare it with an established score for all surgical patients (Score for Prediction of Postoperative Respiratory Complications [SPORC])., Results: The study included 2672 patients who underwent resection for lung cancer (1754, development cohort; 918, validation cohort) between 2008 and 2020, of whom 71 (2.7%) were reintubated within 7 days after surgery. Identified score variables were surgical extent and approach, American Society of Anesthesiologists physical status, heart failure, renal disease, and diffusing capacity of the lung for carbon monoxide. The score achieved excellent discrimination in the development cohort (ROC AUC, 0.90; 95% CI, 0.87-0.94) and good discrimination in the validation cohort (ROC AUC, 0.74, 95% CI; 0.66-0.82), thus outperforming the SPORC in both cohorts (P < .001 and P = .018, respectively; validation cohort net reclassification improvement, 0.39; 95% CI, 0.18-0.60; P = .001). The score cutoff of ≥5 yielded a sensitivity of 88% (95% CI, 72-95) and a specificity of 81% (95% CI,79-83) in the development cohort., Conclusions: A simple score (PROREAL) specific to lung cancer predicts postoperative reintubation more accurately than the nonspecific SPORC score. Operative candidates at risk may be identified for preventive intervention or alternative oncologic therapy., (Copyright © 2024 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objectives: High mechanical power and driving pressure (ΔP) have been associated with postoperative respiratory failure (PRF) and may be important parameters guiding mechanical ventilation. However, it remains unclear whether high mechanical power and ΔP merely reflect patients with poor respiratory system mechanics at risk of PRF. We investigated the effect of mechanical power and ΔP on PRF in cohorts after exact matching by patients' baseline respiratory system compliance., Design: Hospital registry study., Setting: Academic hospital in New England., Patients: Adult patients undergoing general anesthesia between 2008 and 2020., Intervention: None., Measurements and Main Results: The primary exposure was high (≥ 6.7 J/min, cohort median) versus low mechanical power and the key-secondary exposure was high (≥ 15.0 cm H 2 O) versus low ΔP. The primary endpoint was PRF (reintubation or unplanned noninvasive ventilation within seven days). Among 97,555 included patients, 4,030 (4.1%) developed PRF. In adjusted analyses, high intraoperative mechanical power and ΔP were associated with higher odds of PRF (adjusted odds ratio [aOR] 1.37 [95% CI, 1.25-1.50]; p < 0.001 and aOR 1.45 [95% CI, 1.31-1.60]; p < 0.001, respectively). There was large variability in applied ventilatory parameters, dependent on the anesthesia provider. This facilitated matching of 63,612 (mechanical power cohort) and 53,260 (ΔP cohort) patients, yielding identical baseline standardized respiratory system compliance (standardized difference [SDiff] = 0.00) with distinctly different mechanical power (9.4 [2.4] vs 4.9 [1.3] J/min; SDiff = -2.33) and ΔP (19.3 [4.1] vs 11.9 [2.1] cm H 2 O; SDiff = -2.27). After matching, high mechanical power and ΔP remained associated with higher risk of PRF (aOR 1.30 [95% CI, 1.17-1.45]; p < 0.001 and aOR 1.28 [95% CI, 1.12-1.46]; p < 0.001, respectively)., Conclusions: High mechanical power and ΔP are associated with PRF independent of patient's baseline respiratory system compliance. Our findings support utilization of these parameters for titrating mechanical ventilation in the operating room and ICU., Competing Interests: Drs. Talmor and Baedorf-Kassis received funding from Hamilton Medical. Drs. Talmor and Schaefer received funding from Mindray Medical. Dr. Amato’s institution received funding from Covidien/Mdtronics, Orange Med/Nihon Kohden, and Timpel; he disclosed that he is a minority shareholder in Timpel. Dr. Schaefer received funding from Jeffrey and Judy Buzen, Merck & Co., and Fisher and Paykel Healthcare; he disclosed that he is an Associate Editor for BMC Anesthesiology. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2023 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Purpose: We sought to develop and validate an Anticipated Surveillance Requirement Prediction Instrument (ASRI) for prediction of prolonged postanesthesia care unit length of stay (PACU-LOS, more than four hours) after ambulatory surgery., Methods: We analyzed hospital registry data from patients who received anesthesia care in ambulatory surgery centres (ASCs) of university-affiliated hospital networks in New York, USA (development and internal validation cohort [n = 183,711]) and Massachusetts, USA (validation cohort [n = 148,105]). We used stepwise backwards elimination to create ASRI., Results: The model showed discriminatory ability in the development, internal, and external validation cohorts with areas under the receiver operating characteristic curve of 0.82 (95% confidence interval [CI], 0.82 to 0.83), 0.82 (95% CI, 0.81 to 0.83), and 0.80 (95% CI, 0.79 to 0.80), respectively. In cases started in the afternoon, ASRI scores ≥ 43 had a total predicted risk for PACU stay past 8 p.m. of 32% (95% CI, 31.1 to 33.3) vs 8% (95% CI, 7.9 to 8.5) compared with low score values (P-for-interaction < 0.001), which translated to a higher direct PACU cost of care of USD 207 (95% CI, 194 to 2,019; model estimate, 1.68; 95% CI, 1.64 to 1.73; P < 0.001) The effects of using the ASRI score on PACU use efficiency were greater in a free-standing ASC with no limitations on PACU bed availability., Conclusion: We developed and validated a preoperative prediction tool for prolonged PACU-LOS after ambulatory surgery that can be used to guide scheduling in ambulatory surgery to optimize PACU use during normal work hours, particularly in settings without limitation of PACU bed availability., (© 2023. Canadian Anesthesiologists' Society.)

Objective: We estimated hospital costs associated with postoperative reintubation and tested the hypothesis that prolonged surveillance in the post-anesthesia care unit (PACU) modifies the hospital costs of reintubation., Design: Retrospective observational research study., Setting: Two tertiary care academic healthcare networks in the Bronx, New York and Boston, Massachusetts, USA., Patients: 68,125 adult non-cardiac surgical patients undergoing general anesthesia between 2016 and 2021., Interventions: The exposure variable was unplanned reintubation within 7 days of surgery., Measurements: The primary outcome was direct hospital costs associated with patient care related activities. We used a multivariable generalized linear model based on log-transformed costs data, adjusting for pre- and intraoperative confounders. We matched our data with data from the Healthcare Cost and Utilization Project-National Inpatient Sample (HCUP-NIS). In the key secondary analysis, we examined if prolonged postoperative surveillance, defined as PACU utilization (≥4 h) modifies the association between reintubation and costs of care., Main Results: 1759 (2.6%) of patients were re-intubated within 7 days after surgery. Reintubation was associated with higher direct hospital costs (adjusted model estimate 2.05; 95% CI: 2.00-2.10) relative to no reintubation. In the HCUP-NIS matched cohort, the adjusted absolute difference (AD adj ) in costs amounted to US$ 18,837 (95% CI: 17,921-19,777). The association was modified by the duration of PACU surveillance (p-for-interaction <0.001). In patients with a shorter PACU length of stay, reintubation occurred later (median of 2 days; IQR 1, 5) versus 1 days (IQR 0, 2; p < .001), and was associated with magnified effects on hospital costs compared to patients who stayed in the PACU longer (AD adj of US$ 23,444, 95% CI: 21,217-25,799 versus AD adj of US$ 17,615, 95% CI: 16,350-18,926; p < .001)., Conclusion: Postoperative reintubation is associated with 2-fold higher hospital costs. Prolonged surveillance in the recovery room mitigated this effect. The cost-saving effect of longer PACU length of stay was likely driven by earlier reintubation in patients who needed this intervention., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: Latent class analysis (LCA) has identified hyper- and non-hyper-inflammatory subphenotypes in patients with acute respiratory distress syndrome (ARDS). It is unknown how early inflammatory subphenotypes can be identified in patients at risk of ARDS. We aimed to test for inflammatory subphenotypes upon presentation to the emergency department., Methods: LIPS-A was a trial of aspirin to prevent ARDS in at-risk patients presenting to the emergency department. In this secondary analysis, we performed LCA using clinical, blood test, and biomarker variables., Results: Among 376 (96.4%) patients from the LIPS-A trial, two classes were identified upon presentation to the emergency department (day 0): 72 (19.1%) patients demonstrated characteristics of a hyper-inflammatory and 304 (80.9%) of a non-hyper-inflammatory subphenotype. 15.3% of patients in the hyper- and 8.2% in the non-hyper-inflammatory class developed ARDS (p = 0.07). Patients in the hyper-inflammatory class had fewer ventilator-free days (median [interquartile range, IQR] 28[23-28] versus 28[27-28]; p = 0.010), longer intensive care unit (3[2-6] versus 0[0-3] days; p < 0.001) and hospital (9[6-18] versus 5[3-9] days; p < 0.001) length of stay, and higher 1-year mortality (34.7% versus 20%; p = 0.008). Subphenotypes were identified on day 1 and 4 in a subgroup with available data (n = 244). 77.9% of patients remained in their baseline class throughout day 4. Patients with a hyper-inflammatory subphenotype throughout the study period (n = 22) were at higher risk of ARDS (36.4% versus 10.4%; p = 0.003)., Conclusion: Hyper- and non-hyper-inflammatory subphenotypes may precede ARDS development, remain identifiable over time, and can be identified upon presentation to the emergency department. A hyper-inflammatory subphenotype predicts worse outcomes., (© 2023. Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: We studied the primary hypothesis that the training level of anesthesiology residents (first clinical anesthesia year, CA1 vs CA2/3 residents) is associated with early postoperative desaturation (oxygen saturation < 90%). We also analyzed the change in the rate (trajectory) of desaturation during the resident's development from CA1 to CA2/3 resident, and its effects on postoperative respiratory complications., Design: Retrospective hospital registry study., Setting: Two university-affiliated hospitals networks (MA and NY, USA)., Patients: 140,818 adults undergoing non-cardiac surgery under general anesthesia and extubation in the operating room by residents (n = 378) between 2005 and 2021., Measurements: Multivariate logistic and quantile regression were used in the analyses. The secondary outcome was major respiratory complication within 7 days after surgery., Main Results: In 6.5% and 1.6% of cases, early postoperative desaturation to < 90% and 80% occurred. Compared to CA2/3 residents, CA1 residents had higher odds of experiencing early postoperative desaturation to < 90% and 80% (adjusted odds ratio [ORadj], 1.07; 95%CI 1.03-1.12; p = 0.002, and ORadj 1.10; 95%CI 1.01-1.20; p = 0.037, respectively). The change in postoperative desaturation rate during the transition from CA1 to CA2/3 status varied substantially from ORadj 0.80 (decreased risk) to 1.33 (increased risk). Major respiratory complication did not differ between experience levels (p = 0.52). However, a strong decline in improvement regarding the rate of postoperative desaturation during the transition from CA1 to CA2/3, was paralleled by an increased odds of major respiratory complication for CA2/3 residents (ORadj 1.20; 95%CI 1.02-1.42; p = 0.026, p-for-interaction = 0.056)., Conclusion: Patients treated by CA1 residents have an increased risk of postoperative desaturation. Some residents show an improvement and others a decline in postoperative desaturation rate. Our secondary analysis suggests that there should be more focus on those residents who had a declining performance in postoperative desaturation despite becoming more experienced., Competing Interests: Declaration of Competing Interest Matthias Eikermann and Maximilian S. Schaefer received a grant from Merck not related to this study. Maximilian S. Schaefer is an associate editor for BMC Anesthesiology. He received honoraria for presentations from Fisher & Paykel Healthcare and Mindray Medical International Limited, as well as funds from philanthropic donors Jeffrey and Judith Buzen. All other authors have no conflicts of interest to disclose., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Studies linked a high intensity of mechanical ventilation, measured as high mechanical power (MP) to postoperative respiratory failure (PRF) in the setting of two-lung ventilation. We investigated whether a higher MP during one-lung ventilation (OLV) is associated with PRF., Methods: In this registry-based study, adult patients who underwent general anesthesia with OLV for thoracic surgeries between 2006 and 2020 at a New England tertiary healthcare network were included. The association between MP during OLV and PRF (emergency non-invasive ventilation or reintubation within seven days) was assessed in a cohort weighted through a generalized propensity score conditional on a priori defined preoperative and intraoperative factors. Dominance of components of MP and intensity of OLV versus two-lung ventilation in predicting PRF was investigated., Results: Out of 878 included patients, 106 (12.1%) developed PRF. The median (IQR) MP during OLV was 9.8 J/min (7.5-11.8) and 8.3 J/min (6.6-10.2) in patients with and without PRF respectively. A higher MP during OLV was associated with PRF (OR adj 1.22 per 1 J/min increase; 95%CI 1.13-1.31; p < 0.001) and characterized by a U-shaped dose-response curve, with the lowest probability of PRF (7.5%) at 6.4 J/min. Dominance analysis of PRF predictors showed a stronger contribution of driving pressure over respiratory rate and tidal volume, the dynamic over the static component of MP, and MP during OLV over two-lung ventilation (contribution to Pseudo-R 2 : 0.017, 0.021, and 0.036, respectively)., Conclusion: A higher intensity of OLV, mainly driven by driving pressure, is dose-dependently associated with PRF and might constitute a target for mechanical ventilation., (Copyright © 2023 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.)

Objectives: To describe incidence and risk factors of loss of previous independent living through nonhome discharge or discharge home with health assistance in survivors of intensive care unit (ICU) admission for coronavirus disease 2019 (COVID-19)., Design: Multicenter observational study including patients admitted to the ICU from January 2020 till June 30, 2021., Hypothesis: We hypothesized that there is a high risk of nonhome discharge in patients surviving ICU admission due to COVID-19., Setting: Data were included from 306 hospitals in 28 countries participating in the SCCM Discovery Viral Infection and Respiratory Illness Universal Study COVID-19 registry., Patients: Previously independently living adult ICU survivors of COVID-19., Interventions: None., Measurements and Main Results: The primary outcome was nonhome discharge. Secondary outcome was the requirement of health assistance among patients who were discharged home. Out of 10 820 patients, 7101 (66%) were discharged alive; 3791 (53%) of these survivors lost their previous independent living status, out of those 2071 (29%) through nonhome discharge, and 1720 (24%) through discharge home requiring health assistance. In adjusted analyses, loss of independence on discharge among survivors was predicted by patient age ≥ 65 years (adjusted odds ratio [aOR] 2.78, 95% confidence interval [CI] 2.47-3.14, P  < .0001), former and current smoking status (aOR 1.25, 95% CI 1.08-1.46, P   =  .003 and 1.60 (95% CI 1.18-2.16), P   =  .003, respectively), substance use disorder (aOR 1.52, 95% CI 1.12-2.06, P   =  .007), requirement for mechanical ventilation (aOR 4.17, 95% CI 3.69-4.71, P  < .0001), prone positioning (aOR 1.19, 95% CI 1.03-1.38, P   =  .02), and requirement for extracorporeal membrane oxygenation (aOR 2.28, 95% CI 1.55-3.34, P  < .0001)., Conclusions: More than half of ICU survivors hospitalized for COVID-19 are unable to return to independent living status, thereby imposing a significant secondary strain on health care systems worldwide.

Background: The recommendation for transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) in patients 65 to 80 years of age is equivocal, leaving patients with a difficult decision. We evaluated whether TAVR compared to SAVR is associated with reduced odds for loss of independent living in patients ≤65, 66 to 79, and ≥80 years of age. Further, we explored mechanisms of the association of TAVR and adverse discharge., Methods: Adult patients undergoing TAVR or SAVR within a large academic medical system who lived independently before the procedure were included. A multivariable logistic regression model, adjusting for a priori defined confounders including patient demographics, preoperative comorbidities, and a risk score for adverse discharge after cardiac surgery, was used to assess the primary association. We tested the interaction of patient age with the association between aortic valve replacement (AVR) procedure and loss of independent living. We further assessed whether the primary association was mediated (ie, percentage of the association that can be attributed to the mediator) by the procedural duration as prespecified mediator., Results: A total of 1751 patients (age median [quartiles; min-max], 76 [67, 84; 23-100]; sex, 56% female) were included. A total of 27% (222/812) of these patients undergoing SAVR and 20% (188/939) undergoing TAVR lost the ability to live independently. In our cohort, TAVR was associated with reduced odds for loss of independent living compared to SAVR (adjusted odds ratio [OR adj ] 0.19 [95% confidence interval {CI}, 0.14-0.26]; P < .001). This association was attenuated in patients ≤65 years of age (OR adj 0.63 [0.26-1.56]; P = .32) and between 66 and 79 years of age (OR adj 0.23 [0.15-0.35]; P < .001), and magnified in patients ≥80 years of age (OR adj 0.16 [0.10-0.25]; P < .001; P -for-interaction = .004). Among those >65 years of age, a shorter procedural duration mediated 50% (95% CI, 28-76; P < .001) of the beneficial association of TAVR and independent living., Conclusions: Patients >65 years of age undergoing TAVR compared to SAVR had reduced odds for loss of independent living. This association was partly mediated by shorter procedural duration. No association between AVR approach and the primary end point was found in patients ≤65 years of age., Competing Interests: Conflicts of Interest: See Disclosures at the end of this article., (Copyright © 2023 International Anesthesia Research Society.)

Objective: We examined the effects of dexamethasone on postoperative mortality, recurrence-free survival, and side effects in patients undergoing oncologic operations., Background: Dexamethasone prevents nausea and vomiting after anesthesia and may affect cancer proliferation., Methods: A total of 30,561 adult patients undergoing solid cancer resection between 2005 and 2020 were included. Multivariable logistic regression was applied to investigate the effect of dexamethasone on 1-year mortality and recurrence-free survival. Effect modification by the cancer's potential for immunogenicity, defined as a recommendation for checkpoint inhibitor therapy based on the National Comprehensive Cancer Network guidelines, was investigated through interaction term analysis. Key safety endpoints were dexamethasone-associated risk of hyperglycemia >180 mg/dL within 24 hours and surgical site infections within 30 days after surgery., Results: Dexamethasone was administered to 38.2% (11,666/30,561) of patients (6.5±2.3 mg). Overall, 3.2% (n=980/30,561) died and 15.4% (n=4718/30,561) experienced cancer recurrence within 1 year of the operation. Dexamethasone was associated with a -0.6% (95% confidence interval: -1.1, -0.2, P =0.007) 1-year mortality risk reduction [adjusted odds ratio (OR adj ): 0.79 (0.67, 0.94), P =0.009; hazard ratio=0.82 (0.69, 0.96), P =0.016] and higher odds of recurrence-free survival [OR adj : 1.28 (1.18, 1.39), P <0.001]. This effect was only present in patients with solid cancers who were defined as not to respond to checkpoint inhibitor therapy [OR adj : 0.70 (0.57, 0.87), P =0.001 vs OR adj : 1.13 (0.85, 1.50), P =0.40]. A high (>0.09 mg/kg) dose of dexamethasone increased the risk of postoperative hyperglycemia [OR adj : 1.55 (1.32, 1.82), P <0.001], but not for surgical site infections [OR adj : 0.84 (0.42, 1.71), P =0.63]., Conclusions: Dexamethasone is associated with decreased 1-year mortality and cancer recurrence in patients undergoing surgical resection of cancers that are not candidates for immune modulators. Dexamethasone increased the risk of postoperative hyperglycemia, however, no increase in surgical site infections was identified., Competing Interests: M.E. has received grants for investigator-initiated trials not related to this manuscript from Merck & Co. and serves as a consultant on the advisory board of Merck & Co. He is an Associate Editor of the British Journal of Anaesthesia . M.S. has received grants for investigator-initiated studies not related to this manuscript from Merck & Co. and is an Associate Editor of BMC Anesthesiology . T.T.H. reports grants from the National Institute of Neurological Disorders and Stroke (PI), grants from the National Institute of General Medical Sciences, personal fees from Headache, personal fees from Anesthesiology, and personal fees from Cephalalgia outside the submitted work; no other relationships or activities that could appear to have influenced the submitted work. The remaining authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Previous studies linked a high intensity of ventilation, measured as mechanical power, to mortality in patients suffering from "classic" ARDS. By contrast, mechanically ventilated patients with a diagnosis of COVID-19 may present with intact pulmonary mechanics while undergoing mechanical ventilation for longer periods of time. We investigated whether an association between higher mechanical power and mortality is modified by a diagnosis of COVID-19., Methods: This retrospective study included critically ill, adult patients who were mechanically ventilated for at least 24 h between March 2020 and December 2021 at a tertiary healthcare facility in Boston, Massachusetts. The primary exposure was median mechanical power during the first 24 h of mechanical ventilation, calculated using a previously validated formula. The primary outcome was 30-day mortality. As co-primary analysis, we investigated whether a diagnosis of COVID-19 modified the primary association. We further investigated the association between mechanical power and days being alive and ventilator free and effect modification of this by a diagnosis of COVID-19. Multivariable logistic regression, effect modification and negative binomial regression analyses adjusted for baseline patient characteristics, severity of disease and in-hospital factors, were applied., Results: 1,737 mechanically ventilated patients were included, 411 (23.7%) suffered from COVID-19. 509 (29.3%) died within 30 days. The median mechanical power during the first 24 h of ventilation was 19.3 [14.6-24.0] J/min in patients with and 13.2 [10.2-18.0] J/min in patients without COVID-19. A higher mechanical power was associated with 30-day mortality (OR adj 1.26 per 1-SD, 7.1J/min increase; 95% CI 1.09-1.46; p = 0.002). Effect modification and interaction analysis did not support that this association was modified by a diagnosis of COVID-19 (95% CI, 0.81-1.38; p-for-interaction = 0.68). A higher mechanical power was associated with a lower number of days alive and ventilator free until day 28 (IRR adj 0.83 per 7.1 J/min increase; 95% CI 0.75-0.91; p < 0.001, adjusted risk difference - 2.7 days per 7.1J/min increase; 95% CI - 4.1 to - 1.3)., Conclusion: A higher mechanical power is associated with elevated 30-day mortality. While patients with COVID-19 received mechanical ventilation with higher mechanical power, this association was independent of a concomitant diagnosis of COVID-19., (© 2023. The Author(s).)

Background: Combining oxygen facemask with apnoeic oxygenation using high-flow-nasal-oxygen (HFNO) for preoxygenation in the operating room has not been studied against standard oxygen facemask alone. We hypothesized that facemask-alone would be associated with lower levels of lowest end-tidal oxygen (EtO2) within 2 min after intubation in comparison with facemask combined with HFNO., Methods: In an international prospective before-after multicentre study, we included adult patients intubated in the operating room from September 2022 to December 2022. In the before period, preoxygenation was performed with facemask-alone, which was removed during laryngoscopy. In the after period, facemask combined with HFNO was used for preoxygenation and HFNO for apnoeic oxygenation during laryngoscopy. HFNO was maintained throughout intubation. The primary outcome was the lowest EtO2 within 2 min after intubation. The secondary outcome was SpO2 ≤ 95% within 2 min after intubation. Subgroup analyses were performed in patients without and with obesity. This study was registered 10 August 2022 with ClinicalTrials.gov, number NCT05495841., Results: A total of 450 intubations were evaluated, 233 with facemask-alone and 217 with facemask combined with HFNO. In all patients, the lowest EtO2 within 2 min after intubation was significantly lower with facemask-alone than with facemask combined with HFNO, 89 (85-92)% vs 91 (88-93)%, respectively (mean difference - 2.20(- 3.21 to - 1.18), p < 0.001). In patients with obesity, similar results were found [87(82-91)% vs 90(88-92)%, p = 0.004]; as in patients without obesity [90(86-92)% vs 91(89-93)%, p = 0.001)]. SpO2 ≤ 95% was more frequent with facemask-alone (14/232, 6%) than with facemask combined with HFNO (2/215, 1%, p = 0.004). No severe adverse events were recorded., Conclusions: Combining facemask with HFNO for preoxygenation and apnoeic oxygenation was associated with increased levels of lowest EtO2 within 2 min after intubation and less desaturation., (© 2023. The Author(s).)

Competing Interests: Drs Baedorf-Kassis and Talmor disclose a relationship with Hamilton Medical. The remaining authors have disclosed no conflicts of interest.

Reversing neuromuscular blockade with sugammadex can eliminate residual paralysis, which has been associated with postoperative respiratory complications. There are equivocal data on whether sugammadex reduces these when compared with neostigmine. We investigated the association of the choice of reversal drug with postoperative respiratory complications and advanced healthcare utilisation. We included adult patients who underwent surgery and received general anaesthesia with sugammadex or neostigmine reversal at two academic healthcare networks between January 2016 and June 2021. The primary outcome was postoperative respiratory complications, defined as post-extubation oxygen saturation < 90%, respiratory failure requiring non-invasive ventilation, or tracheal re-intubation within 7 days. Our main secondary outcome was advanced healthcare utilisation, a composite outcome including: 7-day unplanned intensive care unit admission; 30-day hospital readmission; or non-home discharge. In total, 5746 (6.9%) of 83,250 included patients experienced postoperative respiratory complications. This was not associated with the reversal drug (adjusted OR (95%CI) 1.01 (0.94-1.08); p = 0.76). After excluding patients admitted from skilled nursing facilities, 8372 (10.5%) patients required advanced healthcare utilisation, which was not associated with the choice of reversal (adjusted OR (95%CI) 0.95 (0.89-1.01); p = 0.11). Equivalence testing supported an equivalent effect size of sugammadex and neostigmine on both outcomes, and neostigmine was non-inferior to sugammadex with regard to postoperative respiratory complications or advanced healthcare utilisation. Finally, there was no association between the reversal drug and major adverse cardiovascular events (adjusted OR 1.07 (0.94-1.21); p = 0.32). Compared with neostigmine, reversal of neuromuscular blockade with sugammadex was not associated with a reduction in postoperative respiratory complications or post-procedural advanced healthcare utilisation., (© 2022 Association of Anaesthetists.)

Background: Encapsulation of rocuronium or vecuronium with sugammadex can reverse neuromuscular block faster than neostigmine reversal. This pharmacodynamic profile might facilitate patient discharge after ambulatory surgery., Methods: We included patients who underwent ambulatory surgery with general anaesthesia and neuromuscular block between 2016 and 2021 from hospital registries at two large academic healthcare networks in the USA. The primary outcome was postoperative length of stay in the ambulatory care facility (PLOS-ACF). We examined post hoc whether the type of reversal affects postoperative nausea and vomiting and direct hospital costs., Results: Among the 29 316 patients included, 8945 (30.5%) received sugammadex and 20 371 (69.5%) received neostigmine for reversal. PLOS-ACF and costs were lower in patients who received sugammadex vs neostigmine (adjusted difference in PLOS-ACF: -9.5 min; 95% confidence interval [95% CI], -10.5 to -8.5 min; adjusted difference in direct hospital costs: -US$77; 95% CI, -$88 to -$66; respectively; P<0.001). The association was magnified in patients over age 65 yr, with ASA physical status >2 undergoing short procedures (<2 h) (adjusted difference in PLOS-ACF: -18.2 min; 95% CI, -23.8 to -12.4 min; adjusted difference in direct hospital costs: -$176; 95% CI, -$220 to -$128; P<0.001). Sugammadex use was associated with reduced postoperative nausea and vomiting (17.2% vs 19.6%, P<0.001), which mediated its effects on length of stay., Conclusions: Reversal with sugammadex compared with neostigmine was associated with a small decrease in postoperative length of stay in the ambulatory care unit. The effect was magnified in older and high-risk patients, and can be explained by reduced postoperative nausea and vomiting. Sugammadex reversal in ambulatory surgery may also help reduce cost of care., (Copyright © 2022 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: Preclinical studies suggest that ketamine stimulates breathing. We investigated whether adding a ketamine infusion at low and high doses to propofol sedation improves inspiratory flow and enhances sedation in spontaneously breathing critically ill patients., Methods: In this prospective interventional study, twelve intubated, spontaneously breathing patients received ketamine infusions at 5 mcg/kg/min, followed by 10 mcg/kg/min for 1 h each. Airway flow, pressure, and esophageal pressure were recorded during a spontaneous breathing trial (SBT) at baseline, and during the SBT conducted at the end of each ketamine infusion regimen. SBT consisted of one-minute breathing with zero end-expiratory pressure and no pressure support. Changes in inspiratory flow at the pre-specified time points were assessed as the primary outcome. Ketamine-induced change in beta-gamma electroencephalogram power was the key secondary endpoint. We also analyzed changes in other ventilatory parameters respiratory timing, and resistive and elastic inspiratory work of breathing., Results: Ketamine infusion of 5 and 10 mcg/kg/min increased inspiratory flow (median, IQR) from 0.36 (0.29-0.46) L/s at baseline to 0.47 (0.32-0.57) L/s and 0.44 (0.33-0.58) L/s, respectively ( p  = .013). Resistive work of breathing decreased from 0.4 (0.1-0.6) J/l at baseline to 0.2 (0.1-0.3) J/l after ketamine 10 mcg/kg/min ( p  = .042), while elastic work of breathing remained unchanged. Electroencephalogram beta-gamma power (19-44 Hz) increased compared to baseline ( p  < .01)., Conclusions: In intubated, spontaneously breathing patients receiving a constant rate of propofol, ketamine increased inspiratory flow, reduced inspiratory work of breathing, and was associated with an "activated" electroencephalographic pattern. These characteristics might facilitate weaning from mechanical ventilation.

Purpose: To evaluate whether intraoperative ventilation using lower driving pressure decreases the risk of nonhome discharge., Methods: We conducted a historical cohort study of patients aged ≥ 60 yr who were living at home before undergoing elective, noncardiothoracic surgery at two tertiary healthcare networks in Massachusetts between 2007 and 2018. We assessed the association of the median driving pressure during intraoperative mechanical ventilation with nonhome discharge using multivariable logistic regression analysis, adjusted for patient and procedural factors. Contingent on the primary association, we assessed effect modification by patients' baseline risk and mediation by postoperative respiratory failure., Results: Of 87,407 included patients, 12,584 (14.4%) experienced nonhome discharge. In adjusted analyses, a lower driving pressure was associated with a lower risk of nonhome discharge (adjusted odds ratio [aOR], 0.88; 95% confidence interval [CI], 0.83 to 0.93, per 10 cm H 2 O decrease; P < 0.001). This association was magnified in patients with a high baseline risk (aOR, 0.77; 95% CI, 0.73 to 0.81, per 10 cm H 2 O decrease, P-for-interaction < 0.001). The findings were confirmed in 19,518 patients matched for their baseline respiratory system compliance (aOR, 0.90; 95% CI, 0.81 to 1.00; P = 0.04 for low [< 15 cm H 2 O] vs high [≥ 15 cm H 2 O] driving pressures). A lower risk of respiratory failure mediated the association of a low driving pressure with nonhome discharge (20.8%; 95% CI, 15.0 to 56.8; P < 0.001)., Conclusions: Intraoperative ventilation maintaining lower driving pressure was associated with a lower risk of nonhome discharge, which can be partially explained by lowered rates of postoperative respiratory failure. Future randomized controlled trials should target driving pressure as a potential intervention to decrease nonhome discharge., (© 2023. Canadian Anesthesiologists' Society.)

Background: Previous studies indicated an association between impaired cerebral perfusion and post-procedural neurological disorders. We investigated whether intra-procedural hypoxaemia or hypocapnia are associated with delirium after surgery., Methods: Inpatients ≥60 yr of age undergoing anaesthesia for surgical or interventional procedures between 2009 and 2020 at an academic healthcare network in the USA (Massachusetts) were included in this hospital registry study. The primary exposure was intra-procedural hypoxaemia, defined as peripheral oxygen saturation <90% for >2 cohering min. The co-primary exposure was hypocapnia during general anaesthesia, defined as end-tidal carbon dioxide pressure ≤25 mm Hg for >5 cohering min. The primary outcome was delirium within 7 days after surgery., Results: Of 71 717 included patients, 1702 (2.4%) developed postoperative delirium, and hypoxaemia was detected in 2532 (3.5%). Of 42 894 patients undergoing general anaesthesia, 532 (1.2%) experienced hypocapnia. The occurrence of either hypoxaemia (adjusted odds ratio [OR adj ]=1.71; 95% confidence interval [CI], 1.40-2.07; P<0.001) or hypocapnia (OR adj =1.77; 95% CI, 1.30-2.41; P<0.001) was associated with a higher risk of delirium within 7 days. Both associations were dependent on the magnitude, and increased with event duration (OR adj =1.03; 95% CI, 1.02-1.04; P<0.001 and OR adj =1.01; 95% CI, 1.00-1.01; P=0.005, for each minute increase in the longest continuous episode, respectively). There was no association between occurrence of hypercapnia and postoperative delirium (OR adj =1.24; 95% CI, 0.90-1.71; P=0.181)., Conclusions: Intra-procedural hypoxaemia and hypocapnia were dose-dependently associated with a higher risk of postoperative delirium. These findings support maintaining normal gas exchange to avoid postoperative neurological disorders., (Copyright © 2022 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)