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Background: Surgery is the primary treatment for non-small cell lung cancer (NSCLC), but microscopic residual disease may be unavoidable. Preclinical studies have shown that volatile anesthetics might suppress host immunity and promote a pro-malignant environment that supports cancer cell proliferation, migration, and angiogenesis, whereas propofol may preserve cell-mediated immunity and inhibit tumor angiogenesis. However, clinical evidence that propofol-based total intravenous anesthesia (TIVA) can reduce tumor recurrence after curative resection remains inconsistent due to the retrospective observational nature of previous studies. Therefore, we will test the hypothesis that the recurrence-free survival (RFS) after curative resection of NSCLC is higher in patients who received TIVA than volatile anesthetics (GAS) in this multicenter randomized trial., Methods: This double-blind, randomized trial will enroll patients at 22 international sites, subject to study registration, institutional review board approval, and patient written informed consent. Eligible patients are adult patients undergoing lung resection surgery with curative intent for NSCLC. Exclusion criteria will be contraindications to study drugs, American Society of Anesthesiologists physical status IV or higher, or preexisting distant metastasis or malignant tumor in other organs. At each study site, enrolled subjects will be randomly allocated into the TIVA and GAS groups with a 1:1 ratio. This pragmatic trial does not standardize any aspect of patient care. However, potential confounders will be balanced between the study arms. The primary outcome will be RFS. Secondary outcomes will be overall survival and complications within postoperative 7 days. Enrollment of 5384 patients will provide 80% power to detect a 3% treatment effect (hazard ratio of 0.83) at alpha 0.05 for RFS at 3 years., Discussion: Confirmation of the study hypothesis would demonstrate that a relatively minor and low-cost alteration in anesthetic management has the potential to reduce cancer recurrence risk in NSCLC, an ultimately fatal complication. Rejection of the hypothesis would end the ongoing debate about the relationship between cancer recurrence and anesthetic management., Trial Registration: The study protocol was prospectively registered at the Clinical trials ( https://clinicaltrials.gov , NCT06330038, principal investigator: Hyun Joo Ahn; date of first public release: March 25, 2024) before the recruitment of the first participant., (© 2024. The Author(s).)

Whether the anesthesia technique, inhalational general anesthesia (IGA) or propofol-based anesthesia (PBA), influences the long-term survival of non-metastatic breast cancer (eBC) remain unclear and controversial. We carried out a literature search on 16thJuly, 2022 for studies comparing IGA and PBA in eBC undergoing standard surgery, according to PRISMA 2020. The major endpoint in our study was overall survival (OS). Seventeen studies including four randomized clinical trials and thirteen retrospective cohort studies were included in the meta-analysis. Ten studies provided data for crude OS in unweighted eBC patients (imbalance in baseline characteristics). The summarized estimate HRs of the PBA group versus the IGA group (ten studies, N = 127,774, IGA group: 92,592, PBA group: 35,182.) was 0.83 (95%CI: 0.78-0.89). Compared with IGA, PBA was associated with both better 1-year OS (two studies, N = 104,083, IGA group: 84,074, PBA group: 20,009. Pooled HR = 0.80, 0.73-0.89) and 5-year OS (six studies, N = 121,580, IGA group: 89,472, PBA group: 32,108. HR = 0.80, 0.74-0.87). Ten studies applied PSM method to balance the baseline characteristics. In these weighted patients, PBA still showed a better OS (ten studies, N = 105,459, IGA group: 79,095, PBA group: 26,364. HR = 0.93, 0.87-1.00), a better 1-year OS (two studies, N = 83,007, IGA group: 67,609, PBA group: 15,398. HR = 0.88, 0.78-0.98) and a trend towards a better 5-year OS (nine studies, N = 121,580, IGA group: 76,797, PBA group: 24,066. HR = 0.95, 0.88-1.03). Loco-regional recurrence-free survival (LRRFS) was also better in PBA group (HR = 0.73, 0.61-0.86). The present study is the first comprehensive meta-analysis to demonstrate that propofol-based anesthesia could significantly improve OS and LRRFS in non-metastatic breast cancer patients, compared with inhalational anesthesia., (© 2024. The Author(s).)

Background: Prolonged times to tracheal extubation (≥15 minutes from dressing on the patient) are consequential based on their clinical and economic effect. We evaluated the variability among anesthesia practitioners in their goals for the age-adjusted end-tidal minimum alveolar concentration of sevoflurane (MAC) at surgery end and achievement of their goals., Methods: We prospectively studied a cohort of 56 adult patients undergoing general anesthesia with sevoflurane as the sole anesthetic agent, scheduled operating room time of at least 3 hours, and non-prone positioning. At the start of surgical closure, an observer asked the anesthesia practitioner their goal for MAC when the surgical drapes are lowered (i.e., the functional end of surgery for the studied procedures). When the drapes were lowered, the MAC achieved was recorded, and the values were compared., Results: The standard deviation of the practitioners' MAC goal was large, 0.199 (N = 56 cases, 95% confidence interval 0.17-0.24), not significantly different from the standard deviation of the MAC achieved of 0.253, P = 0.071. The MAC goal and MAC achieved were correlated pairwise, Pearson r =0.65, P < 0.0001. There was no incremental effect of operating room conversation(s) related to case progress on the association (partial correlation ‑0.01, P = 0.96). Differences among practitioners in the MAC achieved at surgery end were consequential. Specifically, for the N = 12 cases with prolonged extubation, the mean MAC was 0.60 (standard deviation 0.10) versus 0.48 (0.21) among the N = 44 cases without prolonged extubation (P = 0.0070)., Conclusions: The standard deviation of the MAC goal among practitioners was sufficiently large to contribute significantly to the variability in the MAC achieved at the end of surgery. We confirmed prospectively that the age-adjusted end-tidal MAC at the end of surgery matters clinically and economically because differences of 0.60 versus 0.48 were associated with more prolonged extubations. Our novel finding is that the MAC achieved ≥0.60 were caused in part by the anesthesia practitioners' stated MAC goals when surgical closures started., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. University of Iowa issued approval #202312572. The University of Iowa Institutional Review Board determined that the prospective observational study, #202312572, does not meet the regulatory definition of human subjects research because the study did “not analyze private identifiable information about anesthesia providers” and “human subjects [were] not involved from a regulatory standpoint.”. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Clevenger et al.)

In this systematic review, the perioperative outcomes of total intravenous anesthesia (TIVA) and volatile anesthesia were compared in obese adults (BMI ≥ 30 kg/m²) undergoing elective surgery. The review analyzed data from 12 randomized-controlled trials involving 935 patients, sourced from PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), Cochrane, Scopus, and Web of Science databases. The focus was on intraoperative vital signs, emergence time, postoperative nausea and vomiting (PONV), duration of post-anesthesia care unit (PACU) stay, and ICU admission rates. Findings showed that TIVA (using propofol) might reduce PONV, but there were no significant differences in other outcomes compared to volatile anesthesia (with desflurane as the most common agent). The review highlights the need for more research, especially comparing sevoflurane with TIVA, to establish clear clinical guidelines for anesthesia in obese patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Kamal et al.)

Background Inhalation anesthesia (IA) and total intravenous anesthesia (TIVA) are common general anesthesia techniques. During rotator cuff repair (RCR), an interscalene block is beneficial for intraoperative and early postoperative pain control. This study aimed to evaluate postoperative outcomes and opioid usage in patients undergoing arthroscopic RCR with an interscalene block and either IA or TIVA. Methodology A retrospective observational study was performed of 478 patients undergoing RCR at a single institution. Demographics, surgical details, intra and postoperative medications, and 90-day outcomes were collected. Univariate and multivariate analyses were performed to evaluate differences between groups. Results In total, 309 (64.6%) patients received IA and 169 (35.3%) received TIVA. Patients receiving IA were more likely to have comorbidities, such as diabetes (p = 0.002), sleep apnea (p = 0.006), gastroesophageal reflux disease (p < 0.001), and hypertension (p < 0.001). After adjusting for differences between groups in the multivariate analysis, patients who received TIVA had significantly shorter surgical time (β = -14.85, p < 0.001) and perioperative time (β = -21.01, p < 0.001) and significantly lower first post-anesthesia care unit Pasero opioid-induced sedation scores (β = -0.022, p = 0.040). Patients who received TIVA were less likely to receive intraoperative narcotics (odds ratio = 0.38; p = 0.031). Conclusions TIVA appears to be a safe and effective anesthetic for patients undergoing arthroscopic RCR. TIVA is a potentially beneficial alternative to IA for this patient population., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2023, Rennie et al.)

Objective: The aim was to evaluate the difference in recovery when comparing total intravenous anesthesia (TIVA) to inhalational gas anesthesia in patients receiving rhinoplasty., Study Design: Retrospective review., Setting: Postoperative anesthesia care unit (PACU)., Methods: Patients who received a functional or cosmetic rhinoplasty at a single academic institution between April 2017 and November 2020 were included. Inhalational gas anesthesia was in the form of sevoflurane. Phase I recovery time, which was defined as the time it took a patient to reach ≥9/10 on the Aldrete scoring system was recorded, as well as the usage of pain medication in the PACU. The postoperative course and incidence of postoperative nausea and vomiting (PONV) were also collected., Results: Two hundred and two patients were identified with 149 (73.76%) who received TIVA and 53 (26.24%) who received sevoflurane. For the patients who received TIVA, the average recovery time was 101.44 minutes (standard deviation [SD]: 34.64) compared to an average recovery time of 121.09 minutes (SD: 50.19) for patients who received sevoflurane leading to a difference of 19.65 minutes (p = 0.002). Patients who received TIVA experienced less PONV (p = 0.001). There were no differences in the postoperative course including surgical or anesthesia complications, postoperative complications, hospital or Emergency Department admissions, or administration of pain medication (p > 0.05 for all)., Conclusion: When utilizing TIVA over inhalational anesthesia, patients undergoing rhinoplasty had significantly increased benefits in terms of reduced phase I recovery times and decreased incidence of PONV. TIVA was demonstrated to be a safe and efficacious method of anesthesia for this patient population., (© 2023 American Academy of Otolaryngology-Head and Neck Surgery Foundation.)

Introduction: To determine if there is a recovery time difference between patients with and without obstructive sleep apnea (OSA) when using total intravenous anesthesia (TIVA) compared to volatile gas inhalational anesthesia., Patients and Methods: OSA and Non-OSA patients were identified at a tertiary institution between January 2019 and November 2020. Non-OSA patients were defined as those who have not been formerly diagnosed with OSA. A modified STOP-BANG score (MSBS) was performed to screen Non-OSA patients for OSA. Recovery was measured by Phase I recovery time, or time it took a patient to reach ≥9/10 on the Aldrete scoring system., Results: A total of 334 patients were included with 142 in the OSA cohort (59 TIVA, 83 inhalational anesthesia) and 192 in the Non-OSA cohort (119 TIVA, 73 inhalational anesthesia). In OSA patients, there was a 41.29-minute recovery time reduction when using TIVA versus sevoflurane ( P  < .0001). Non-OSA patients recovered faster than OSA patients when undergoing inhalational anesthesia by 46.76 minutes and TIVA by 18.58 minutes ( P  < .0001 and P  = .0907, respectively). Non-OSA patients with a MSBS < 3 and ≥3 had a shorter recovery time compared to OSA patients when both underwent sevoflurane anesthesia (57.27 minutes, P  < .0001 and 56.23 minutes, P  = .040, respectively). Non-OSA patients with a MSBS of <3 had a decrease in recovery time of 26.68 minutes when compared to OSA patients who underwent TIVA ( P  = .0004)., Conclusions: When utilizing TIVA over inhalational anesthesia, patients with OSA have significantly increased benefit in terms of reduced Phase I recovery times as compared to Non-OSA patients.

Metastasis or recurrence following curative surgery is the main indicator of tumor progress and is the main cause of patient death. For more than three decades, the potential for general anesthesia to affect cancer outcomes has been a subject of concern with considerable research interest. Here, we conducted this systematic review and meta-analysis to summarize the effect of inhalational anesthesia (IHNA) vs. propofol-based total intravenous anesthesia (TIVA) on metastasis and recurrence after cancer surgery from clinical and pre-clinical studies. The relative risk for metastasis/recurrence in TIVA is 0.61 (95% confidence interval (95% CI) 0.46 to 0.82, p = 0.0009) compared to IHNA. Inflammatory cytokines have been implicated in cancer metastasis following cancer surgery, thus we analyzed inflammatory cytokines levels after surgery under IHNA or TIVA. Based on pooled analysis, a lower IL-6 level was noticed in TIVA in comparison to IHNA (standardized mean difference (SMD) = 0.77, 95% CI = 0.097 to 1.44, I 2 = 92%, p = 0.02) but not TNF-α or IL-10. Preclinical animal model studies show that inhalational anesthetics increase the risk of breast cancer metastasis compared to propofol. In conclusion, the current evidence suggests intravenous anesthetic propofol is associated with less metastasis/recurrence and lower postoperative IL-6 level over inhaled anesthetics in the oncological surgery. We urge more well-designed clinical and preclinical studies in this field.

The reduction of greenhouse gases such as CO 2 emissions and their equivalents (CO2e) generally has three aspects: Fugitive direct emissions (anesthetic gases, exhaust gases), indirect emissions through the purchase of energy (electricity, heat) and emissions in the supply chain (supply of consumables, disposal). Since pediatric anesthesia has a traditional affinity with inhalation, the use of anesthetic gases should be repeatedly questioned and, if possible, avoided on the way to net zero emissions in addition to general measures to conserve resources. In children, analgosedation, total intravenous anesthesia (TIVA) and establishment of venous access prior to the induction of anesthesia are particularly suitable for this purpose. In addition to avoiding greenhouse gases, the methods mentioned offer other significant medical advantages and can also be profitable in terms of safety and comfort. Nevertheless, anesthetic gases are required in pediatric anesthesia in some situations. For this reason, it is important to save anesthetic gases through minimal fresh gas flow and a rational approach to inhalation induction. To facilitate implementation in clinical practice, this article provides recommendations for mask induction and choice of anesthetic procedure., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Objective: Specific guidelines regarding an optimal general anesthesia (GA) approach to obstructive sleep apnea (OSA) patients remain undefined. Literature comparing the efficacy of total intravenous anesthesia (TIVA) and inhalational anesthesia in this population is sparse. We hypothesize that OSA patients receiving TIVA will experience reduced recovery times and other improved post-surgical outcomes., Study Design: Randomized controlled trial., Methods: Adult OSA patients undergoing upper airway surgery (hypoglossal nerve stimulation [HNS], nasal, or palate surgery) from February 2020-December 2020 were included. A post-anesthesia care unit (PACU) nursing survey documented patients' alertness, pain, oxygen supplementation, and postoperative nausea and vomiting from PACU arrival to 2 hours. Perioperative timepoints from the electronic medical record (EMR) and a nurse-estimated Phase I recovery time were collected., Results: One hundred eleven patients were included (46 TIVA and 65 inhalational anesthesia). Per EMR-recorded timepoints, TIVA patients undergoing HNS and palate surgery experienced Phase I Time reductions of 12.5 min (p = 0.042) and 27.5 min (p = 0.016), respectively. Per the PACU survey, TIVA patients undergoing any surgery, HNS, or palate surgery experienced nurse-estimated Phase I Time reductions of 16.5 min (p = 0.004), 12.5 min (p = 0.031), and 38.5 min (p = 0.024), respectively. Overall, TIVA patients experienced higher alertness and pain ratings, and lower oxygen supplementation requirements from PACU arrival to 30 min (p < 0.05)., Conclusion: Patients with OSA receiving TIVA for GA maintenance during upper airway procedures experienced reduced recovery times and oxygen supplementation requirements, and a more rapid return to alertness. Future work toward developing optimized anesthetic guidelines for OSA patients is merited., Level of Evidence: 3 Laryngoscope, 133:984-992, 2023., (© 2022 The American Laryngological, Rhinological and Otological Society, Inc.)

Purpose: Postoperative delirium incidences are increasing in older adults. A Cochrane Review found no significant difference in the incidence of postoperative delirium between total intravenous anesthesia (TIVA) and inhalational anesthesia (IA). This study evaluated the differences in postoperative delirium and morbidity between patients who underwent either TIVA or IA., Methods: A nationwide Japanese inpatient database was used to retrospectively compare differences in postoperative delirium and composite morbidity between patients older than 65 years, who underwent general anesthesia (TIVA or IA). The primary outcome was postoperative delirium. The secondary outcomes were: morbidity incidence, length of hospital stay, and mortality. A 1:3 propensity score analysis of patients who underwent all surgical procedures was conducted according to covariates, to calculate odds ratios and their 95% confidence intervals (CIs). Sensitivity analyses were conducted using an instrumental variable analysis of the proportion of TIVA by hospital scale, stabilized inverse probability of treatment weighting analyses, limiting the definitions of postoperative delirium, and subgroup analysis., Results: Of 738,600 patients, 149,540 received TIVA and 589,060 received IA. After 1:3 propensity score matching, the adjusted odds ratios for postoperative delirium and composite morbidity were 0.93 (95% CI 0.91-0.95) and 0.94 (95% CI 0.90-0.97), respectively, for TIVA concerning IA. There were no differences in the length of the intensive care unit and hospital stay, or hospital mortality. The findings were consistent with the sensitivity analyses., Conclusions: This study demonstrated that TIVA was related to a slightly decreased postoperative delirium and incidence of morbidity compared to IA., (© 2022. The Author(s) under exclusive licence to Japanese Society of Anesthesiologists.)

Background and Objectives: End-stage renal disease (ESRD) is associated with increased anesthetic risks such as cardiovascular events resulting in higher perioperative mortality rates. This study investigated the perioperative and postoperative outcomes in ESRD patients receiving propofol target-controlled infusion with brachial plexus block during arteriovenous (AV) access surgery. Materials and Methods: We recruited fifty consecutive patients scheduled to receive AV access surgery. While all patients received general anesthesia combined with ultrasound-guided brachial plexus block, the patients were randomly assigned to one of two general anesthesia maintenance groups, with 23 receiving propofol target-controlled infusion (TCI) and 24 receiving sevoflurane inhalation. We measured perioperative mean arterial pressure (MAP), heart rate, and cardiac output and recorded postoperative pain status and adverse events in both groups. Results: ESRD patients receiving propofol TCI had significantly less reduction in blood pressure than those receiving sevoflurane inhalation (p < 0.05) during AV access surgery. Perioperative cardiac output and heart rate were similar in both groups. Both groups reported relatively low postoperative pain score and a low incidence of adverse events. Conclusions: Propofol TCI with brachial plexus block can be used as an effective anesthesia regimen for ESRD patients receiving AV access surgery. It can be used with less blood pressure fluctuation than inhalational anesthesia.

Postoperative cognitive dysfunction (POCD) has been increasingly recognized as a contributor to postoperative complications. A consensus-working group recommended that POCD should be distinguished between delayed cognitive recovery, ie, evaluations up to 30 days postoperative, and neurocognitive disorder, ie, assessments performed between 30 days and 12 months after surgery. Additionally, the choice of the anesthetic, either inhalational or total intravenous anesthesia (TIVA) and its effect on the incidence of POCD, has become a focus of research. Our primary objective was to search the literature and conduct a meta-analysis to verify whether the choice of general anesthesia may impact the incidence of POCD in the first 30 days postoperatively. As a secondary objective, a systematic review of the literature was conducted to estimate the effects of the anesthetic on POCD between 30 days and 12 months postoperative. For the primary objective, an initial review of 1913 articles yielded ten studies with a total of 3390 individuals. For the secondary objective, four studies with a total of 480 patients were selected. In the first 30 days postoperative, the odds-ratio for POCD in TIVA group was 0.46 (95% CI = 0.26-0.81; p = 0.01), compared to the inhalational group. TIVA was associated with a lower incidence of POCD in the first 30 days postoperatively. Regarding the secondary objective, due to the small number of selected articles and its high heterogeneity, a metanalysis was not conducted. Given the heterogeneity of criteria for POCD, future prospective studies with more robust designs should be performed to fully address this question., Competing Interests: Ana Fernandez-Bustamante reports grants from NIH/NHLBI, Merck, and US DoD, outside the submitted work. The authors report no other potential conflicts of interest in relation to this work., (© 2022 Negrini et al.)

Background: Endoscopic transsphenoidal pituitary surgery has shown promising results. However, fast and high-quality recovery after this procedure remains a challenge for neuroanesthesiologists. This study aimed to compare the quality of recovery after transsphenoidal pituitary surgery between patients who received inhalational anesthesia with sevoflurane and patients who received propofol-based total intravenous anesthesia (TIVA). Methods: Eighty-two patients undergoing transsphenoidal pituitary surgery were randomized to receive either sevoflurane inhalation with manual infusion of remifentanil (sevoflurane group) or effect-site target-controlled infusion of propofol and remifentanil (TIVA group). The primary outcome was the 40-item Quality of Recovery (QoR-40) score on postoperative day 1. The QoR-40 questionnaire was completed by patients the day before surgery and on postoperative days 1 and 2. Emergence agitation and recovery characteristics were also assessed. Results: There were no significant differences between the groups in the global QoR-40 scores on both postoperative days 1 and 2 (difference -8.7, 95% CI -18.0 to 0.7, and P = 0.204; -3.6, 95% CI -13.0 to 5.8, and P > 0.999, respectively). The time to verbal response and time to extubation were significantly shorter in the sevoflurane group than in the TIVA group ( P < 0.001 and P < 0.001, respectively). However, the incidence of emergence agitation was lower in the TIVA group than in the sevoflurane group ( P < 0.001). Conclusions: Both inhalational anesthesia with sevoflurane and propofol-based TIVA were appropriate anesthetic techniques for patients undergoing endoscopic transsphenoidal pituitary surgery in terms of the quality of recovery up to 2 days postoperatively. Rapid emergence was observed in the sevoflurane group, while smooth emergence was observed in the TIVA group., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Background: The details of the public demonstration of the effects of ether that initiated the modern era of surgery and anesthesia are often misreported. Existing published transcripts of the clinical records are incomplete or inaccurate., Methods: The patient notes of Gilbert Abbott were photographed, transcribed, and reviewed., Results: The records are handwritten in "Surgical Records for 1846; Volume 30," of the Massachusetts General Hospital. The patient was admitted on September 25. The presenting condition was a congenital, mobile, compressible, multilobed, small lesion at the angle of the left mandible, and base of tongue. The operation on October 16 was an attempted ligation of the blood supply to the lesion. The postoperative diagnosis was a vascular lesion ("erectile tumor"). Postoperative management included application of sclerosants. The mass was unchanged in size on discharge on December 7. There is no documentation of the anesthetic administration in the progress note but a retrospective report of the anesthetic is pasted into the Records book. This account reported that the patient did not respond to the initial incision. He moved and cried out during the latter part of the procedure. Although he was aware of the operation taking place, he later said he had not experienced pain. The commentary concluded that the demonstration of the analgesic effectiveness of ether was inconclusive but that subsequently ether was shown to be effective., Conclusions: The surgery on October 16, an unsuccessful ligation of a congenital lymphovascular malformation, was performed under incomplete general anesthesia. Examination of the primary documents may allow for more accurate accounts of circumstances surrounding the discovery of anesthesia., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Deep brain stimulation (DBS) improves Parkinson's disease (PD) symptoms by suppressing neuropathological oscillations. These oscillations are also modulated by inhalational anesthetics used during DBS surgery in some patients, influencing electrode placement accuracy. We sought to evaluate a method that could avoid these effects. We recorded subthalamic nucleus (STN) neuronal firings in 11 PD patients undergoing DBS under inhalational anesthesia. Microelectrode recording (MER) during DBS was collected under median nerve stimulation (MNS) delivered at 5, 20, and 90 Hz frequencies and without MNS. We analyzed the spike firing rate and neuronal activity with power spectral density (PSD), and assessed correlations between the neuronal oscillation parameters and clinical motor outcomes. No patient experienced adverse effects during or after DBS surgery. PSD analysis revealed that peripheral 20 Hz MNS produced significant differences in the dorsal and ventral subthalamic nucleus (STN) between the beta band oscillation (16.9 ± 7.0% versus 13.5 ± 4.8%, respectively) and gamma band oscillation (56.0 ± 13.7% versus 66.3 ± 9.4%, respectively) ( p < 0.05). Moreover, 20-Hz MNS entrained neural oscillation over the dorsal STN, which correlated positively with motor disabilities. MNS allowed localization of the sensorimotor STN and identified neural characteristics under inhalational anesthesia. This paradigm may help identify an alternative method to facilitate STN identification and DBS surgery under inhalational anesthesia.

Recent data suggest that the type of anesthesia used during the resection of solid tumors impacts the long-term survival of patients favoring total-intravenous-anesthesia (TIVA) over inhalative-anesthesia (INHA). Here we sought to query this impact on survival in patients undergoing resection of glioblastoma (GBM). All patients receiving elective resection of a newly diagnosed, isocitrate-dehydrogenase-1-(IDH1)-wildtype GBM under general anesthesia between January 2010 and June 2017 in the Department of Neurosurgery, Heidelberg University Hospital, were included. Patients were grouped according to the applied anesthetic technique. To adjust for potential prognostic confounders, patients were matched in a 1:2 ratio (TIVA vs. INHA), taking into account the known prognostic factors: age, extent of resection, O-6-methylguanine-DNA-methyltransferase-(MGMT)-promoter-methylation-status, pre-operative Karnofsky-performance-index and adjuvant radio- and chemotherapy. The primary endpoint was progression-free-survival (PFS) and the secondary endpoint was overall-survival (OS). In the study period, 576 patients underwent resection of a newly diagnosed, IDH-wildtype GBM. Patients with incomplete follow-up-data, on palliative treatment, having emergency or awake surgery; 54 patients remained in the TIVA-group and 417 in the INHA-group. After matching, 52 patients remained in the TIVA-group and 92 in the INHA-group. Median PFS was 6 months in both groups. The median OS was 13.5 months in the TIVA-group and 13.0 months in the INHA-group. No significant survival differences associated with the type of anesthesia were found either before or after adjustment for known prognostic factors. This retrospective study supports the notion that the current anesthetic approaches employed during the resection of IDH-wildtype GBM do not impact patient survival., (© 2020. The Author(s).)

Numerous studies have demonstrated the ability of isoflurane conditioning to provide multifaceted protection against aneurysmal subarachnoid hemorrhage (SAH)-associated delayed cerebral ischemia (DCI); however, preclinical studies have not yet examined whether other commonly used inhalational anesthetics in neurological patients such as sevoflurane or desflurane are also protective against SAH-induced neurovascular deficits. We therefore sought to identify the potential for sevoflurane and desflurane conditioning to protect against DCI in an endovascular perforation mouse model of SAH. Neurological function was assessed daily via neuroscore. Large artery vasospasm and microvessel thrombosis were assessed three days after SAH or sham surgery. Four groups were examined: Sham, SAH + room air, SAH + 2% Sevoflurane, and SAH + 6% Desflurane. For the SAH groups, one hour after surgery, mice received 2% sevoflurane, 6% desflurane, or room air for one hour. We found that conditioning with sevoflurane or desflurane attenuated large artery vasospasm, reduced microvessel thrombosis, and improved neurologic function. Given their frequent clinical use and strong safety profile in patients (including those with SAH), these data strongly support further studies to validate these findings in preclinical and clinical studies and to elucidate the mechanisms by which these agents might be acting.

More than 70 years after its original report, the hypoxic pulmonary vasoconstriction (HPV) response continues to spark scientific interest on its mechanisms and clinical implications, particularly for anesthesiologists involved in thoracic surgery. Selective airway intubation and one-lung ventilation (OLV) facilitates the surgical intervention on a collapsed lung while the HPV redirects blood flow from the "upper" non-ventilated hypoxic lung to the "dependent" ventilated lung. Therefore, by limiting intrapulmonary shunting and optimizing ventilation-to-perfusion (V/Q) ratio, the fall in arterial oxygen pressure (PaO 2 ) is attenuated during OLV. The HPV involves a biphasic response mobilizing calcium within pulmonary vascular smooth muscles, which is activated within seconds after exposure to low alveolar oxygen pressure and that gradually disappears upon re-oxygenation. Many factors including acid-base balance, the degree of lung expansion, circulatory volemia as well as lung diseases and patient age affect HPV. Anesthetic agents, analgesics and cardiovascular medications may also interfer with HPV during the perioperative period. Since HPV represents the homeostatic mechanism for regional ventilation-to-perfusion matching and in turn, for optimal pulmonary oxygen uptake, a clear understanding of HPV is clinically relevant for all anesthesiologists., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Saudi Journal of Anesthesia.)

Objectives/hypothesis: The differences between intravenous and inhalation anesthesia in clinical postoperative pulmonary complications (PPCs) have been studied in cardiac and lung resection surgery. Clinical evidence for the effects of these two anesthetics on PPCs in other types of surgery is still missing. We aimed to assess the impact of sevoflurane and propofol on the incidence of PPCs in patients undergoing surgery for head and neck cancer., Study Design: Double-blind, randomized, controlled trial., Methods: We assigned 220 adults at intermediate-to-high risk of PPCs scheduled for head and neck cancer surgery with radial forearm or fibular flap reconstruction to either propofol or sevoflurane as a general anesthetic. The occurrence of pulmonary complications according to the Clavien-Dindo score was defined as the primary (within 7 days after surgery) outcome., Results: The PPC incidence during 7 days after surgery was 32.4% and 18.2% in the propofol and sevoflurane groups, respectively (P = .027). The corresponding incidence of PPCs in patients who underwent tracheotomy at the end of surgery in the two groups was 44.8% and 24.5%, respectively (P = .030). In addition, the Clavien-Dindo classification showed significant differences between groups in minor complications (grades I and II) but not in major complications (grades III-V)., Conclusions: Compared with intravenous anesthesia, the administration of sevoflurane reduces the incidence of minor PPCs (grades I and II) in moderate- and high-risk patients who have undergone tracheotomy after head and neck cancer surgery with radial forearm or fibular flap reconstruction., Level of Evidence: 2 Laryngoscope, 131:E108-E115, 2021., (© 2020 The American Laryngological, Rhinological and Otological Society, Inc.)

An Ohio dentist, Corydon Munson, patented a gasometer with an attachment for vaporizing trace amounts of volatile general anesthetics or their mixtures into unoxygenated nitrous oxide. After vaporizing a variant of George Harley's ACE mixture into nitrous oxide, Munson branded his own novel anesthetic combination as ACENO., (Copyright © 2020 Anesthesia History Association. Published by Elsevier Inc. All rights reserved.)

It is well known that low fresh gas flows result in lower cost of inhalational agents. A new generation of carbon dioxide absorbents allows low flow anesthesia with all anesthetics but these new compounds are more expensive. This study examines the cost of inhalational anesthesia at different fresh gas flows combined with the cost of absorbent. The cost of sevoflurane and desflurane is lower at low fresh gas flows. Paradoxically the cost of isoflurane is cheaper at 2 L/min than at lower fresh gas flows due to increased cost of carbon dioxide absorbent. Therefore low fresh gas flows should be used when feasible with sevoflurane and desflurane, but higher fresh gas flows up to 2 L/min may be more economical with isoflurane during maintenance phase of anesthesia.

Background: Inhalational anesthesia and total intravenous anesthesia (TIVA) are techniques used for maintenance of general anesthesia for endoscopic sinus surgery (ESS). Growing evidence exists that TIVA may be associated with decreased bleeding and improved surgical fields, yet data suggest it is used in a minority of sinus surgery cases. The objective of this study was to investigate perceptions and approaches to anesthetic maintenance techniques in ESS among anesthesia providers., Methods: A total of 719 anesthesiology residents, faculty, and certified registered nurse anesthetists (CRNAs) at 3 tertiary academic centers in the United States were invited to participate in a survey of considerations and practice patterns for inhalational anesthesia and TIVA for ESS., Results: Responses were received from 200 participants (28%). Sixty-five percent of respondents reported a lack of familiarity with current literature on TIVA for ESS. Many considered factors other than surgical field visualization when choosing a maintenance technique. Most were comfortable with performing TIVA but stated they would participate in additional training., Conclusion: The majority of anesthesiology providers were unaware of the existing literature demonstrating advantage in improved surgical visualization with TIVA. Many used a combination of inhaled and intravenous anesthetics for maintenance. These findings suggest that future opportunities may exist to develop education, training, and practice approaches specific to anesthetic techniques for ESS., (© 2019 ARS-AAOA, LLC.)

The ability to monitor the inspired and expired concentrations of volatile anesthetic gases in real time makes these drugs implicitly targetable. However, the end-tidal concentration only represents the concentration within the brain and the vessel rich group (VRG) at steady state, and very poorly approximates the VRG concentration during common dynamic situations such as initial uptake and emergence. How should the vaporization of anesthetic gases be controlled in order to optimally target VRG concentration in clinical practice? Using a generally accepted pharmacokinetic model of uptake and redistribution, a transfer function from the vaporizer setting to the VRG is established and transformed to the time domain. Targeted actuation of the vaporizer in a time-optimal manner is produced by a variable structure, sliding mode controller. Direct mathematical application of the controller produces rapid cycling at the limits of the vaporizer, further prolonged by low fresh gas flows. This phenomenon, known as "chattering", is unsuitable for operating real equipment. Using a simple and clinically intuitive modification to the targeting algorithm, a variable low-pass boundary layer is applied to the actuation, smoothing discontinuities in the control law and practically eliminating chatter without prolonging the time taken to reach the VRG target concentration by any clinically significant degree. A model is derived for optimum VRG-targeted control of anesthetic vaporizers. An alternate and further application is described, in which deliberate perturbation of the vaporization permits non-invasive estimation of parameters such as cardiac output that are otherwise difficult to measure intra-operatively.

Background: Propofol and remifentanil intravenous combination is one popular form of total intravenous anesthesia (TIVA) in mainstream clinical practice, but it has rarely been applied to a rat model for laryngoscopy and laryngeal electromyography (LEMG). Our objective was to establish a safe and reproducible general anesthetic protocol for laryngoscopy and endoscopic LEMG in a rat model. Our hypothesis is that TIVA allows a minimally morbid, and feasible laryngoscopy and LEMG., Methods: Sprague Dawley rats were subjected to either inhalational anesthesia (IA) (isoflurane) or TIVA (propofol and remifentanil) and underwent laryngoscopy and LEMG. The primary outcome was a complete minimally interrupted rigid laryngoscopy and obtaining reproducible motor unit potentials from the posterior cricoarytenoid muscles. The secondary outcome was morbidity and mortality., Results: Seventeen out of twenty-two rats underwent both TIVA and IA. Only two underwent IA only. All nineteen rats that underwent IA had a successful experiment. Seventeen rats underwent TIVA, however, only nine completed a successful experiment due to difficulty achieving a surgical plane, and respiratory events. Upon comparing the success of the two anaesthetic regimens, IA was superior to TIVA (P = 0.0008). There was no statistical difference between the amplitudes (p = 0.1985) or motor units burst duration (p = 0.82605) of both methods. Three mortalities were encountered, one of which was due to lidocaine toxicity and two were during anesthetic induction. Respiratory related morbidity was encountered in two rats, all seen with TIVA., Conclusions: TIVA is not an ideal anesthetic regimen for laryngeal endoscopy and LEMG in rat models. Contrary to our hypothesis, IA did not affect the quality of the LEMG and allowed a seamless rigid endoscopy.

We describe an unusual case of hyperacute hepatic failure following general anesthesia in a patient receiving a simultaneous kidney-pancreas transplant. Despite an aggressive evaluation of structural, immunological, viral, and toxicological causes, a definitive cause could not be elucidated. The patient required a liver transplant and suffered a protracted hospital course. We discuss the potential causes of fulminant hepatic failure and the perioperative anesthesia management of her subsequent liver transplantation., (Copyright © 2018 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.)

Purpose: After a radical gastrectomy, patients may experience severe pain. Some studies have reported that the use of propofol significantly reduced postoperative pain, while others have argued that this effect was not significant. Thus, we aimed to assess whether anesthesia with propofol could help to reduce pain after an open radical gastrectomy procedure., Patients and Methods: Sixty patients who were scheduled to undergo a laparotomy for radical gastrectomy were randomly assigned to either the propofol or sevoflurane group (n=30 each). A target-controlled infusion of propofol or inhalation of sevoflurane, titrated to bispectral index of 40-60, was maintained. All patients were administered a standardized multimodal analgesic plan, including intraoperative dexmedetomidine, dexamethasone, and postoperative flurbiprofen axetil, as well as patient-controlled fentanyl. Hemodynamics, pain scores, fentanyl consumption, adverse events, and the incidence of chronic pain 1 month and 3 months following hospital discharge were recorded., Results: The intensity of postoperative pain was relatively low to moderate in all the patients. The propofol group showed lower pain scores, at rest and while coughing, up to 48 h postoperatively compared to the sevoflurane group ( P< 0.05). Cumulative fentanyl consumption 0-24 h after surgery was lower for the propofol group (364.4 ± 139.1 vs. 529.3 ± 237.9 µg; P =0.002). However, for fentanyl consumption 0-48 h, the difference between the two groups was not significant (710.9 ± 312.8 vs. 850.9 ± 292.0 µg; P =0.078). There were no differences in the incidences of adverse events or chronic pain between the groups., Conclusions: Overall, the multimodal analgesic approach reduced postoperative pain after an open radical gastrectomy procedure in all patients anesthetized with either propofol or sevoflurane. Furthermore, our results indicated better analgesic outcome for the propofol group, especially in the early postoperative period., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Objective: To outline the major components of the minimum alveolar concentration (MAC) and review the literature regarding pharmacological manipulation of the MAC of halothane, isoflurane, sevoflurane, enflurane, and desflurane in dogs. The pharmacological agents included are alpha-2 agonists, benzodiazepines, propofol, opioids, lidocaine, acepromazine, non-steroidal anti-inflammatory agents (NSAIDs), maropitant, and NMDA antagonists. Part 2 of this review will focus on the effect of opioids, lidocaine, NSAIDs, maropitant, acepromazine, and NMDA antagonists on MAC., Databases Used: PubMed, Google Scholar, CAB Abstracts. Search terms used: minimum alveolar concentration, MAC, dog, canine, inhaled anesthetic potency, isoflurane, sevoflurane, desflurane, enflurane, and halothane., Conclusions: Opioids, lidocaine, NSAIDs, maropitant, acepromazine, and NMDA antagonists have been shown to reduce the MAC of inhaled anesthetics in dogs and allow for clinically important decreases in inhalant anesthetic use. Thus, the use of these agents potentially decrease the adverse cardiovascular and pulmonary effects associated with the use of high concentrations of inhaled anesthetics., (Published by Elsevier Ltd.)

Background and Aims: In contrast to propofol, volatile agents are often considered harmful to maintain anesthesia due to increasing brain volume and potential deleterious effects. Patients for cranioplasty, including patients with large bone defects, could be susceptible for intraoperative complications but have not properly been investigated so far. The aim of the present study was to evaluate brain swelling, intraoperative conditions, surgical course, and postoperative complication rates of propofol-based vs. volatile-based anesthesia., Material and Methods: In this monocentric, retrospective, and observational study, we collected demographic, clinical, and outcome data of patients undergoing cranioplasty between December 2010 and September 2014. According to the hypnotic drug used, patients were assigned to either a propofol or a volatile group. The primary outcome parameter was brain swelling. For comparison of the groups, univariate analysis was performed using Chi-square and Mann-Whitney-U test., Results: One hundred and one patients were identified in the period. Twenty-three patients were excluded due to cerebrospinal fluid diversion. Baseline characteristics and preoperative conditions did not vary between the groups except a higher body mass index and positive end-expiratory pressure (PEEP) in the propofol group. The choice of anesthesia (volatile or intravenous) influence neither the intraoperative local conditions nor postoperative complication rate. No significant risk factor for impaired bone flap placement was identified., Conclusions: In a well-defined cohort, the choice of the anesthetic agent does not influence the degree of intraoperative brain swelling, bone flap fit, and postoperative course., Competing Interests: Bernd W. Böttiger is European Resuscitation Council (ERC) Board Director Science and Research; Chairman of the German Resuscitation Council (GRC); Member of the Advanced Life Support (ALS) Task Force of the International Liaison Committee on Resuscitation (ILCOR); Member of the executive committee of the German Interdisciplinary Association for Intensive and Emergency Medicine (DIVI); Associated Editor of the European Journal of Anaesthesiology (EJA), Co-Editor of “Resuscitation”; Editor of the Journal “Notfall + Rettungsmedizin”. He received professional fees for lectures from the following companies: Medupdate GmbH, “Forum für medizinische Fortbildung (FomF)”, Baxalta Deutschland GmbH, Bayer Vital GmbH, ZOLL Medical Deutschland GmbH, C. R. Bard GmbH.

Objective: To outline the major components of the minimum alveolar concentration (MAC) and review the literature in regard to pharmacological manipulation of the MAC of halothane, isoflurane, sevoflurane, enflurane, and desflurane in dogs. The pharmacologic agents included are alpha-2 agonists, benzodiazepines, propofol, maropitant, opioids, lidocaine, acepromazine, non-steroidal anti-inflammatory agents, and NMDA antagonists. Part 1 will focus on summarizing the relevance, measurement, and mechanisms of MAC and review the effects of alpha-2 agonists, benzodiazepines, and propofol on MAC., Databases Used: PubMed, Google Scholar, CAB Abstracts. Search terms used: minimum alveolar concentration, MAC, dog, canine, inhaled anesthetic potency, isoflurane, sevoflurane, desflurane, enflurane, and halothane., Conclusions: Many drugs reduce the MAC of inhaled anesthetics in dogs, and allow for a clinically important decrease in inhalant anesthetic use. A decrease in MAC may decrease the adverse cardiovascular and pulmonary effects associated with the use of high concentrations of inhaled anesthetics., (Published by Elsevier Ltd.)

The aim of the present study was to evaluate the safety and efficacy of various general anesthesia regimens during endoscopic variceal ligation (EVL) and endoscopic variceal sclerotherapy (EVS). A total of 123 patients with American Society of Anesthesiologists physical status III and IV, aged 40-70 years, undergoing general anesthesia for EVL and EVS were randomly divided into two groups: Sevoflurane anesthesia (group S; n=60) and propofol anesthesia (group P; n=60). Vital signs, particularly heart rate (HR) and mean arterial pressure (MAP), were monitored. The designated time points were as follows: 5 min before induction (T0), and 1, 5, 10, 15, 20, 25 and 30 min after intubation (T1, T2, T3, T4, T5, T6 and T7, respectively). Time intervals were recorded, including recovery time and extubation time. Following surgery, the observer recorded the Ramsay sedation scale (RSS) score and the visual analogue scale (VAS) score. Adverse reactions were noted. Results demonstrated that there were significant differences in MAP between the two groups at T2, T3, T5, T6 and T7 (P<0.05). There was a significant difference in HR between the two groups at T2, T3 and T4 (P<0.05). Recovery time and extubation time in group P were significantly longer than those in group S (P<0.05; 18.38±2.25 min vs. 14.57±1.04 min and 21.70±2.70 min vs. 15.83±0.88 min, respectively). The rate of ephedrine injected was 58.3% (35/60 patients) in group P vs. 28.3% (17/60 patients) in group S (P<0.05). There was a significant difference in the RSS score between the two groups 5 min after extubation (P<0.05). VRS scores demonstrated that anesthetists and patients were significantly more satisfied with the procedure in group S than in group P (P<0.01). In conclusion, the superiority and special clinical value of inhalational anesthesia has been demonstrated during EVL and EVS attributed to stable hemodynamics and high quality of anesthesia recovery in the present study.

Objectives: To evaluate the clinical efficacy of masking the odor of inhalational agents using fruit flavors on the anxiety behavior and compliance of children for inhalational induction., Methods: A prospective randomized double blind, placebo controlled study was conducted on 60 unpremedicated children in the age group of 4-12 y. Thirty children received anesthetic masks smeared with a flavor of child's choice while the other 30 children were induced using masks without flavor. Anxiety was assessed using modified Yale Pre-operative Anxiety Scale (mYPAS) in the pre-op room and during inhalational induction. Mask acceptance was graded by Induction Compliance Checklist (ICC). The cost-effectiveness of flavored anesthetic masks was compared to that of commercially available pre-scented masks., Results: The baseline anxiety in the two groups was comparable. The number of children demonstrating high levels of anxiety at anesthetic induction was similar in flavored and non-flavored mask groups (p 0.45). The compliance to mask induction was also equally good (p 0.99). The authors found significant difference in the cost of flavored mask (INR 56.45 per mask) as compared to commercially available pre-scented masks (INR 660 per mask)., Conclusions: The authors observed a placebo effect that reduced the pre-op anxiety in the control group which probably made the quality of induction equivalent with flavored and non-flavored masks. Therefore, using a flavored anesthetic mask is cost-effective than using a commercially available pre-scented mask.

Background and Objectives: Functional endoscopic sinus surgery (FESS) being a delicate technique, intraoperative bleeding is one of the major challenges. Even a little bleeding can adversely affect the surgeon's ability to visualize the region to be operated. General anesthesia is preferred over topical anesthesia in FESS. This study was conducted to compare the surgical field using total intravenous anesthesia (TIVA) with propofol and inhalational anesthesia with isoflurane for FESS. Secondary outcomes such as intraoperative blood loss and the incidence of perioperative complications were also recorded., Subjects and Methods: A total of sixty patients in the age group of 16-60 years with physical status American Society of Anesthesiologists Classes I and II, undergoing FESS were randomly divided into two groups of thirty each after taking informed consent and approval from the Hospital Ethics Committee. Thirty patients in Group I: received isoflurane-based inhalational anesthesia and other Thirty patients in Group II: were administered TIVA with propofol. Various parameters were recorded and statistically analyzed., Results: There was improved quality of surgical field at the end of surgery in the Group II as compared to Group I. Total blood loss during surgery and incidence of intraoperative complications were less in Group II as compared to Group I., Conclusion: This study concludes that in FESS, using TIVA with propofol decreases blood loss and the incidence of complications during surgery in addition to providing good quality of surgical field., Competing Interests: There are no conflicts of interest.

Isoflurane is a widely used inhaled anesthetic in the clinical setting. However, the mechanism underlying its effect on consciousness is under discussion. Therefore, we investigated the effect of isoflurane on the hippocampus and cortex using an in vivo field recording approach. Our results showed that 1.3%, 0.8%, and 0.4% isoflurane exerted an inhibitory influence on the mouse hippocampus and cortex. Further, high frequency bands in the cortex and hippocampus showed greater suppression with increasing isoflurane concentration. Our findings suggest that in vivo field recordings can monitor the effect of isoflurane anesthesia on the mouse cortex and hippocampus., Competing Interests: Conflicts of Interest: None declared.

Autoregulation of blood flow is a key feature of the human cerebral vascular system to assure adequate oxygenation and metabolism of the brain under changing physiological conditions. The impact of advanced age and anesthesia on cerebral autoregulation remains unclear. The primary objective of this study was to determine the effect of sevoflurane anesthesia on cerebral autoregulation in two different age groups. This is a follow-up analysis of data acquired in a prospective observational cohort study. One hundred thirty-three patients aged 18-40 and ≥65 years scheduled for major noncardiac surgery under general anesthesia were included. Cerebral autoregulation indices, limits, and ranges were compared in young and elderly patient groups. Forty-nine patients (37 %) aged 18-40 years and 84 patients (63 %) aged ≥65 years were included in the study. Age-adjusted minimum alveolar concentrations of sevoflurane were 0.89 ± 0.07 in young and 0.99 ± 0.14 in older subjects (P < 0.001). Effective autoregulation was found in a blood pressure range of 13.8 ± 9.8 mmHg in young and 10.2 ± 8.6 mmHg in older patients (P = 0.079). The lower limit of autoregulation was 66 ± 12 mmHg and 73 ± 14 mmHg in young and older patients, respectively (P = 0.075). The association between sevoflurane concentrations and autoregulatory capacity was similar in both age groups. Our data suggests that the autoregulatory plateau is shortened in both young and older patients under sevoflurane anesthesia with approximately 1 MAC. Lower and upper limits of cerebral blood flow autoregulation, as well as the autoregulatory range, are not influenced by the age of anesthetized patients. Trial registration ClinicalTrials.gov (NCT00512200).

Nitrous oxide and the volatile inhalational anesthetics have defined anxiety and pain control in both dentistry and medicine for over a century. From curious experimentation to spectacular public demonstrations, the initial work of 2 dentists, Horace Wells and William T. G. Morton, persists to this day in modern surgery and anesthesia. This article reviews the history, similarities, differences, and clinical applications of the most popular inhalational agents used in contemporary dental surgical settings.

Background Context: False-positive loss of transcranial electrical motor evoked potentials (TCe-MEPs) limits the efficacy of motor tract monitoring during spine surgery. Although total intravenous anesthesia (TIVA) is widely regarded as the optimal regimen for TCe-MEPs, inhalational anesthesia is an alternative regimen., Purpose: To compare the rates of false-positive TCe-MEPs during spine surgery for patients anesthetized with TIVA and inhalation anesthesia., Study Design: A retrospective analysis of data collected from consecutive patients undergoing TCe-MEP monitoring during spinal surgery., Patient Sample: Consecutive adult patients from multiple surgical centers undergoing spine surgery inclusive of cervical or thoracic spinal levels during 2008-2009 who received TIVA or inhalation anesthesia., Outcome Measures: The primary outcome measure was the rate of false-positive alerts using TCe-MEPS, defined as a persistent loss of 90% or greater of the amplitude of TCe-MEP in one or more muscles not attributed to technical or transient systemic factors (hypotension or hypoxia) and not associated with any postoperative neurologic deficit., Methods: Patients were divided into two groups according to anesthetic regimen: those anesthetized with one or more inhalational agents (n=1,303) and patients anesthetized with TIVA (n=511). The Fisher exact test and unpaired t test were used to compare group characteristics and false-positive rates. Each group was further subdivided by spinal region (cervical, thoracic, and thoracolumbar) and by presence of preoperative motor deficit. A Pearson chi-squared test was used to identify differences according to spinal region. This study was not supported by any financial sources nor do the authors have any financial relationships to disclose., Results: Patient with inhaled anesthesia showed significantly higher rates of false-positive TCe-MEP changes (15.0% vs. 3.2%) compared with the TIVA group. These differences were significant across all surgical subgroups. The inhaled group had a larger number of patients with preoperative motor deficits compared with TIVA (45.0% vs. 37.4%), a potential confounder for false-positive results. However, a significantly higher rate of false-positive TCe-MEP changes was still observed in the inhaled group (11.4% vs. 0.6% for TIVA) when analyzing only those patients without preoperative motor deficits., Conclusions: Use of inhalation anesthesia during adult spinal surgery is associated with significantly higher rates of false-positive changes compared with TIVA during TCe-MEP monitoring. This relationship appears independent of preoperative motor status. Further study and multivariate analysis of anesthetic agents, diagnosis, and symptoms is necessary to elucidate the impact of these variables. The potential confounding effects of inhalational anesthesia on TCe-MEP monitoring should be considered when determining anesthetic regimen., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: Cost and environmental pollution are two prime concerns with general anesthesia. We hypothesized that target-controlled (TC) anesthesia drug delivery system also called as end-tidal (ET) control is an effective and safe system that would reduce the cost and also environmental pollution., Materials and Methods: We studied 200 patients undergoing laparoscopic abdominal and pelvic surgeries and randomly distributed those in 2 groups of 100 each, TC and manual-controlled (MC) group. We reviewed the two groups in term of consumption of gases, time required to achieve the ET concentration of sevoflurane of 1.5%, maximum inspired concentration of sevoflurane achieved, and number of adjustments required to maintain the depth of anesthesia., Results: We found that the consumption of nitrous oxide and sevoflurane was significantly less in TC group than MC group (P < 0.05), oxygen consumption was also less in TC group but not statistically significant. The time required to achieve the desired levels, maximum inspired sevoflurane concentration achieved, and the number of drug delivery adjustments required were statistically significant in TC group (P < 0.05). As the consumption reduced in TC group, the cost of the inhalational anesthesia reduced by approximately Rs. 64/h ($1.12) and thus the environmental pollution., Conclusion: We concluded from our study that ET control is a good system for conserving the consumption of gases and thus is efficient as it reduces both the cost and the environmental pollution.

Background: Total intravenous anesthesia (TIVA) has been shown in some studies to impact visual field, blood loss, and cardiovascular parameters during endoscopic sinus surgery when compared to inhalational anesthesia (IA). These variables are critical in endoscopic sinus surgery. A systematic review and meta-analysis was undertaken to discern the impact of TIVA vs IA in endoscopic sinus surgery., Methods: MEDLINE (1950 to October 20, 2012) was searched using a search strategy designed to include all randomized controlled trials (RCTs) that discussed TIVA, IA, and endoscopic sinus surgery. An abstract search was then used to identify RCTs directly comparing TIVA and IA in endoscopic sinus surgery. All articles selected then underwent full-text review. Data on visual field scores, blood loss, and cardiovascular parameters was then extracted, compared, and analyzed., Results: There were 42 articles identified by the search strategy. Full-text review identified 9 articles that met eligibility criteria and contained extractable data. Although inconsistently reported, preoperative characteristics (Lund-Mackay scores and history of nasal polyps) were similar (p > 0.05) between the 2 groups. No difference was found between heart rate, mean arterial pressure, anesthesia time, operative time, or estimated blood loss. Only 7 studies reported a visibility score, but overall favored the TIVA group (p < 0.001)., Conclusion: Current evidence supporting TIVA is limited to a handful of inconsistently controlled and reported studies. Standardized grading of visibility scores and preoperative characteristics would better establish the role of TIVA in endoscopic sinus surgery., (© 2013 ARS-AAOA, LLC.)