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Abstract Superhydrophobic surfaces that can remain dry under water have a high potential as nontoxic antifouling coatings or for drag‐reducing ship coatings. The Salvinia effect leads to impressive stable air layers on underwater submerged floating plants Salvinia, decisively determined by the hydrophilic tips of the otherwise hydrophobic Salvinia hairs (Salvinia paradox). The water adheres to these hydrophilic tips, stabilizing the water–air interface. An even more important contribution to the stability of the air layer is provided by the air spring, which is formed by the air volume bound by the hydrophilic leaf edge and the leaf base. Using an artificial Salvinia model with hydrophobic pillars (syn‐trichomes), how the stability against pressure changes in water depends on the height of the artificial hair is systematically shown: a reduction of the air spring height from 3 mm to 300 µm increases the stability against negative pressure by 500% from 72 to 380 mbar. Thicker air layers react much more strongly when subjected to overpressure (1000 mbar). It is also shown that the presence of a boundary is essential for the function of the air spring: removing the limiting hydrophilic edge around the hydrophobic air spring reduces the stability against negative pressure by 300%.

PurposeThe aim of this study was to compare two devices for neuromuscular monitoring during anesthetic induction. TOF-Cuff® was installed on the lower leg stimulating the tibial nerve, while the more conventional TOF-Scan® was installed over the ulnar nerve at the wrist. Methods Twenty adult patients were enrolled in this prospective, controlled study. Train-of-four (TOF) was recorded every 15 s until TOF ratio of 0%. Mean arterial blood pressure (MAP) was assessed with TOF-Cuff® and with standard anesthesia monitoring from the brachial artery. MAP was measured before and after anesthetic induction. Time to TOF ratio = 0% was compared with one-sample t test and Bland-Altman plots. Results Patients received 0.53 ± 0.09 mg atracurium per kg body weight intravenously. Mean time to TOF ratio = 0% was 150.8 s (± 43.7) for TOF-Scan®, and 174.4 s (± 42.7) for TOF-Cuff® (p = 0.1356). Bias was - 15.9 (95% confidence interval - 37.5 to 5.6) with 95% limits of agreement of - 95.2 to 63.3. Twenty-five percent of the patients had a technical issue with a TOF-Cuff® measurement. For MAP, mean difference was 1.4 (95% confidence interval - 2.4 to 5.2) with 95% limits of agreement of - 22.7 to 25.5. Conclusion The time from administration of a common dose of atracurium to a TOF ratio of 0% assessed with TOF-Cuff® stimulating the tibial nerve compared to TOF-Scan® stimulating the ulnar nerve showed large limits of agreement in Bland-Altman analysis. There was a high failure rate with TOF-Cuff® measurements on the lower leg.

BackgroundTube size selection is critical in ventilating patients' lungs using double-lumen endobronchial tubes (DLTs). Little information about relevant parameters is readily available from manufacturers. The aim of this study is to provide reference data for relevant dimensions of conventionally available DLTs.MethodsIn this study in a benchmark in vitro setup, several dimensional parameters of four sizes of left-sided double-lumen endobronchial tubes from six different manufacturers were assessed, such as distances and diameters of tube shaft, cuff lengths, and diameters as well the angle at the tip.ResultsEndobronchial tubes of ostensibly the same size revealed wide variation in measured parameters between brands from different manufacturers. In some parameters, there was an overlap between different sizes from the same manufacturer, i.e., diameters and distances did not increase with increasing nominal endobronchial tube size. The information about dimensions of endobronchial tubes provided by manufacturers' leaflets is insufficient.ConclusionsEndobronchial tube size selection carries unnecessary uncertainty because clinically relevant parameters are unknown and vary considerably between different manufacturers.

Abstract Background It remains elusive how the characteristics, the course of disease, the clinical management and the outcomes of critically ill COVID-19 patients admitted to intensive care units (ICU) worldwide have changed over the course of the pandemic. Methods Prospective, observational registry constituted by 90 ICUs across 22 countries worldwide including patients with a laboratory-confirmed, critical presentation of COVID-19 requiring advanced organ support. Hierarchical, generalized linear mixed-effect models accounting for hospital and country variability were employed to analyse the continuous evolution of the studied variables over the pandemic. Results Four thousand forty-one patients were included from March 2020 to September 2021. Over this period, the age of the admitted patients (62 [95% CI 60–63] years vs 64 [62–66] years, p

Background: Accurate risk stratification of critically ill patients with coronavirus disease 2019 (COVID-19) is essential for optimizing resource allocation, delivering targeted interventions, and maximizing patient survival probability. Machine learning (ML) techniques are attracting increased interest for the development of prediction models as they excel in the analysis of complex signals in data-rich environments such as critical care. Methods: We retrieved data on patients with COVID-19 admitted to an intensive care unit (ICU) between March and October 2020 from the RIsk Stratification in COVID-19 patients in the Intensive Care Unit (RISC-19-ICU) registry. We applied the Extreme Gradient Boosting (XGBoost) algorithm to the data to predict as a binary outcome the increase or decrease in patients’ Sequential Organ Failure Assessment (SOFA) score on day 5 after ICU admission. The model was iteratively cross-validated in different subsets of the study cohort. Results: The final study population consisted of 675 patients. The XGBoost model correctly predicted a decrease in SOFA score in 320/385 (83%) critically ill COVID-19 patients, and an increase in the score in 210/290 (72%) patients. The area under the mean receiver operating characteristic curve for XGBoost was significantly higher than that for the logistic regression model (0.86 vs. 0.69, P

Abstract Background Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is widespread. While the risks and benefits of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefits of different respiratory support strategies, employed in intensive care units during the first months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates. Methods Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclassified into standard oxygen therapy ≥10 L/min (SOT), high-flow oxygen therapy (HFNC), noninvasive positive-pressure ventilation (NIV), and early IMV, according to the respiratory support strategy employed at the day of admission to ICU. Propensity score matching was performed to ensure comparability between groups. Results Initially, 1421 patients were assessed for possible study inclusion. Of these, 351 patients (85 SOT, 87 HFNC, 87 NIV, and 92 IMV) remained eligible for full analysis after propensity score matching. 55% of patients initially receiving noninvasive respiratory support required IMV. The intubation rate was lower in patients initially ventilated with HFNC and NIV compared to those who received SOT (SOT: 64%, HFNC: 52%, NIV: 49%, p = 0.025). Compared to the other respiratory support strategies, NIV was associated with a higher overall ICU mortality (SOT: 18%, HFNC: 20%, NIV: 37%, IMV: 25%, p = 0.016). Conclusion In this cohort of critically ill patients with COVID-19, a trial of HFNC appeared to be the most balanced initial respiratory support strategy, given the reduced intubation rate and comparable ICU mortality rate. Nonetheless, considering the uncertainty and stress associated with the COVID-19 pandemic, SOT and early IMV represented safe initial respiratory support strategies. The presented findings, in agreement with classic ARDS literature, suggest that NIV should be avoided whenever possible due to the elevated ICU mortality risk.

STUDY AIM: The surge of admissions due to severe COVID-19 increased the patients-to-critical care staffing ratio within the ICUs. We investigated whether the daily level of staffing was associated with an increased risk of ICU mortality (primary endpoint), length of stay (LOS), mechanical ventilation and the evolution of disease (secondary endpoints). METHODS: We employed a retrospective multicentre analysis of the international Risk Stratification in COVID-19 patients in the ICU (RISC-19-ICU) registry, limited to the period between March 1 and May 31, 2020, and to Switzerland. Hierarchical regression models were used to investigate crude and adjusted effects of the critical care staffing ratio on study endpoints. We adjusted for disease severity and weekly caseload. RESULTS: Among the 38 participating Swiss ICUs, 17 recorded staffing information. The study population included 437 patients and 2,342 daily assessments of patient-to-critical care staffing ratio. Median of daily patient-to-nurse ratio started at 1.0 [IQR 0.5–1.5; calendar week 9] and peaked at 2.4 (IQR 0.4–2.0; calendar week 16), while the median of daily patient-to-physician ratio started at 4.0 (IQR 2.1–5.0; calendar week 9) and peaked at 6.8 (IQR 6.3–7.3; calendar week 19). Neither the patient-to-nurse (adjusted OR 1.28, 95% CI 0.85–1.93; doubling of ratio) nor the patient-to-physician ratio (adjusted OR 1.07, 95% CI 0.87–1.32; doubling of ratio) were associated with ICU mortality. We found no association of daily critical care staffing on the secondary endpoints in adjusted models. CONCLUSION: We found no association of reduced availability of critical care staffing resources in Swiss ICUs with overall ICU length of stay nor mortality. Whether long-term outcome of critically ill patients with COVID-19 have been affected remains to be studied.

Abstract Background The beach chair position that is commonly used in shoulder surgery is associated with relative hypovolemia, which leads to a reduction in arterial blood pressure. The effects of patient positioning on the accuracy of non-invasive continuous blood pressure monitoring with the ClearSight™ system (CS-BP; Edwards Lifesciences, Irvine CA, USA) have not been studied extensively. Our research aim was to assess agreement levels between CS-BP measurements with traditional blood pressure monitoring techniques. Methods For this prospective self-controlled study, we included 20 consecutively treated adult patients undergoing elective shoulder surgery in the beach chair position. We performed Bland-Altman analyses to determine agreement levels between blood pressure values from CS-BP and standard non-invasive (NIBP) methods. Perioperative measurements were done in both the supine (as reference) and beach chair surgical positions. Additionally, we compared invasive blood pressure (IBP) measurements with both the non-invasive methods (CS-BP and NIBP) in a sub-group of patients (n = 10) who required arterial blood pressure monitoring. Results We analyzed 229 data points (116 supine, 113 beach chair) from the entire cohort; per patient measurements were based on surgical length (range 3–9 supine, 2–10 beach chair). The mean difference (±SD; 95% limits of agreement) in the mean arterial pressure (MAP) between CS-BP and NIBP was − 0.9 (±11.0; − 24.0–22.2) in the beach chair position and − 4.9 mmHg (±11.8; − 28.0–18.2) when supine. In the sub-group, the difference between CS-BP and IBP in the beach chair position was − 1.6 mmHg (±16.0; − 32.9–29.7) and − 2.8 mmHg (±15.3; − 32.8–27.1) in the supine position. Between NIBP and IBP, we detected a difference of 3.0 mmHg (±9.1; − 20.8–14.7) in the beach chair position, and 4.6 mmHg (±13.3; − 21.4–30.6) in the supine position. Conclusions We found clinically acceptable mean differences in MAP measurements between the ClearSight™ and non-invasive oscillometric blood pressure systems when patients were in either the supine or beach chair position. For all comparisons of the monitoring systems and surgical positions, the standard deviations and limits of agreement were wide. Trial registration This study was prospectively registered at the German Clinical Trial Register (www.DRKS.de; DRKS00013773 ). Registered 26/01/2018.

Presentación de la presente edición de la Universidade de Santa Cruz do Sul en colaboración con la Universitat Oberta de Catalunya, junto con los investigadores idealizadores Fernanda Pires de Sá, Willian Fernandes Araújo y Antoni Roig.

Background. Tube size selection is critical in ventilating patients’ lungs using double-lumen endobronchial tubes (DLTs). Little information about relevant parameters is readily available from manufacturers. The aim of this study is to provide reference data for relevant dimensions of conventionally available DLTs. Methods. In this study in a benchmark in vitro setup, several dimensional parameters of four sizes of left-sided double-lumen endobronchial tubes from six different manufacturers were assessed, such as distances and diameters of tube shaft, cuff lengths, and diameters as well the angle at the tip. Results. Endobronchial tubes of ostensibly the same size revealed wide variation in measured parameters between brands from different manufacturers. In some parameters, there was an overlap between different sizes from the same manufacturer, i.e., diameters and distances did not increase with increasing nominal endobronchial tube size. The information about dimensions of endobronchial tubes provided by manufacturers’ leaflets is insufficient. Conclusions. Endobronchial tube size selection carries unnecessary uncertainty because clinically relevant parameters are unknown and vary considerably between different manufacturers.

Apresentação da editora chefe dra. Fabiana Piccinin.

Acceleromyometry is the clinical standard for quantitative neuromuscular monitoring, mostly using the stimulation pattern train-of-four (TOF). TOF-Cuff®, a recently introduced neuromuscular monitor with stimulating electrodes integrated within a blood pressure cuff, assesses the muscular response in the upper arm. The time from administration of a neuromuscular blocking agent to TOF-ratio 0% during modified rapid sequence induction was compared between TOF-Cuff® and acceleromyometry (TOF-Scan®). Included were 26 adults with body mass index <35 kg/m2. TOF-Scan® and TOF-Cuff® were simultaneously fitted on patients' opposite arms. The mean difference to TOF-ratio 0% was compared using the one sample t -test (p < 0.05) and Bland–Altman plots. After anesthesia induction, atracurium 0.9 mg/kg (±0.08) i.v. was administered. The mean time to TOF ratio 0% for TOF-Scan® was 140.4 s (±34.3), and 132.7 s (±32.5) for TOF-Cuff®, with a mean difference of 5.4 (95% CI: −9.9 to 20.7, p = 0.472). The maximum difference between the two modalities was 135 s when the TOF-Cuff® was faster and 60 s when the TOF-Scan® was faster. No statistically significant systematic difference was found between TOF-Scan® and TOF-Cuff®. However, there was high variability and wide limits of agreement. The two devices cannot be used interchangeably. [ABSTRACT FROM AUTHOR]

Background: The RemiPCA SAFE Network was established to set standards and monitor maternal and neonatal outcomes when using remifentanil for labour analgesia. The aim of this analysis was to describe the development of the network standard and to report maternal and neonatal outcome data, including severe adverse events.Methods: Data sets of the RemiPCA SAFE Network database from the initial six consecutive years (2010-2015) were retrospectively analysed. The data were analysed on an annual basis and set in context with changes of the network standard, i.e. adaptations of the network's standard operating procedure. Main outcomes reported are maternal and neonatal data regarding effectiveness and safety, such as satisfaction, need for bag/mask ventilation and/or cardiopulmonary resuscitation.Results: Among 5740 data sets, no need for maternal ventilation or cardiopulmonary resuscitation was registered. Neonatal cardiopulmonary resuscitations, potentially related to remifentanil, occurred in 0.3%. In parallel with adaptations of the network standard, a moderate rate of maternal hypoxia (oxygen saturation <94% in 24.7%) was found, together with a low rate of supplemental oxygen requirement in neonates (5.0%).Conclusion: The RemiPCA SAFE Network data show that remifentanil patient-controlled analgesia can be applied safely. There is bias when data from real clinical settings are analysed retrospectively. Notwithstanding, the approach taken by the RemiPCA SAFE Network, with constant, systematic and standardised evaluation of multiple parameters during the course of labour, might identify trends and anomalies and guide the development and application of safety standards, when translating knowledge from scientific trials into clinical practice. [ABSTRACT FROM AUTHOR]

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users.

Objective: Cerebral near-infrared spectroscopy (NIRS) was evaluated for use in monitoring global oxygenation in adult patients after cardiac surgery. Design: Prospective, randomized clinical monitoring study. Setting: Intensive care unit for cardiac surgery; university hospital. Participants: The study included 35 patients scheduled for cardiac surgery with insertion of a pulmonary artery catheter; patients with known cerebral-vascular perfusion disturbances were excluded. Interventions: Noninvasive cerebral NIRS oxygen saturation (rSO2) and conventional intensive care monitoring parameters were assessed. Measurements and Main Results: Simple regression analysis was used to assess the correlation of rSO2 to hemodynamic parameters. There was fair-to-moderate intersubject correlation to hemoglobin concentration (r = 0.45, p < 0.0001) and mixed venous oxygen saturation (SmvO2) (r = 0.33, p < 0.0001). Sensitivity and specificity of rSO2 to detect substantial (≥1 standard deviation) changes in mixed venous oxygen saturation were 94% and 81%, respectively. Conclusions: Cerebral NIRS in adult patients might not be the tool to replace mixed venous oxygen monitoring. Further work has to be done to assess its potential to reflect intraindividual trends. [Copyright &y& Elsevier]