Background: During general anaesthesia for noncardiac surgery, there remain knowledge gaps regarding the effect of goal-directed haemodynamic therapy on patient-centred outcomes. Methods: Included clinical trials investigated goal-directed haemodynamic therapy during general anaesthesia in adults undergoing noncardiac surgery and reported at least one patient-centred postoperative outcome. PubMed and Embase were searched for relevant articles on March 8, 2021. Two investigators performed abstract screening, full-text review, data extraction, and bias assessment. The primary outcomes were mortality and hospital length of stay, whereas 15 postoperative complications were included based on availability. From a main pool of comparable trials, meta-analyses were performed on trials with homogenous outcome definitions. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Results: The main pool consisted of 76 trials with intermediate risk of bias for most outcomes. Overall, goal-directed haemodynamic therapy might reduce mortality (odds ratio¼0.84; 95% confidence interval [CI], 0.64 to 1.09) and shorten length of stay (mean difference¼e0.72 days; 95% CI, e1.10 to e0.35) but with low certainty in the evidence. For both outcomes, larger effects favouring goal-directed haemodynamic therapy were seen in abdominal surgery, very high-risk surgery, and using targets based on preload variation by the respiratory cycle. However, formal tests for subgroup differences were not statistically significant. Goal-directed haemodynamic therapy decreased risk of several postoperative outcomes, but only infectious outcomes and anastomotic leakage reached moderate certainty of evidence.

Background: Controversy exists regarding the effects of a high versus a low intraoperative fraction of inspired oxygen (FiO 2 ) in adults undergoing general anesthesia. This systematic review and meta-analysis investigated the effect of a high versus a low FiO 2 on postoperative outcomes.Methods: PubMed and Embase were searched on March 22, 2022 for randomized clinical trials investigating the effect of different FiO 2 levels in adults undergoing general anesthesia for non-cardiac surgery. Two investigators independently reviewed studies for relevance, extracted data, and assessed risk of bias. Meta-analyses were performed for relevant outcomes, and potential effect measure modification was assessed in subgroup analyses and meta-regression. The evidence certainty was evaluated using GRADE.Results: This review included 25 original trials investigating the effect of a high (mostly 80%) versus a low (mostly 30%) FiO 2 . Risk of bias was intermediate for all trials. A high FiO 2 did not result in a significant reduction in surgical site infections (OR: 0.91, 95% CI 0.81-1.02 [p = .10]). No effect was found for all other included outcomes, including mortality (OR = 1.27, 95% CI: 0.90-1.79 [p = .18]) and hospital length of stay (mean difference = 0.03 days, 95% CI À0.25 to 0.30 [p = .84). Results from subgroup analyses and meta-regression did not identify any clear effect modifiers across outcomes. The certainty of evidence (GRADE) was rated as low for most outcomes.Maria Høybye and Peter C. Lind contributed equally.

BACKGROUND: The optimal ventilation strategy during general anesthesia is unclear. This systematic review investigated the relationship between ventilation targets or strategies (eg, positive end-expiratory pressure [PEEP], tidal volume, and recruitment maneuvers) and postoperative outcomes. METHODS: PubMed and Embase were searched on March 8, 2021, for randomized trials investigating the effect of different respiratory targets or strategies on adults undergoing noncardiac surgery. Two investigators reviewed trials for relevance, extracted data, and assessed risk of bias. Meta-analyses were performed for relevant outcomes, and several subgroup analyses were conducted. The certainty of evidence was evaluated using Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: This review included 63 trials with 65 comparisons. Risk of bias was intermediate for all trials. In the meta-analyses, lung-protective ventilation (ie, low tidal volume with PEEP) reduced the risk of combined pulmonary complications (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.28–0.49; 9 trials; 1106 patients), atelectasis (OR, 0.39; 95% CI, 0.25–0.60; 8 trials; 895 patients), and need for postoperative mechanical ventilation (OR, 0.36; 95% CI, 0.13–1.00; 5 trials; 636 patients). Recruitment maneuvers reduced the risk of atelectasis (OR, 0.44; 95% CI, 0.21–0.92; 5 trials; 328 patients). We found no clear effect of tidal volume, higher versus lower PEEP, or recruitment maneuvers on postoperative pulmonary complications when evaluated individually. For all comparisons across targets, no effect was found on mortality or hospital length of stay. No effect measure modifiers were found in subgroup analyses. The certainty of evidence was rated as very low, low, or moderate depending on the intervention and outcome. CONCLUSIONS: Although lung-protective ventilation results in a decrease in pulmonary complications, randomized clinical trials provide only limited evidence to guide specific ventilation strategies during general anesthesia for adults undergoing noncardiac surgery.

This study investigated the immunomodulatory influence of IL10 producing B regulatory cells, Bregs (CD19+CD24hiCD38hi) to standard Twinrix® vaccination. We also investigated HBsAg specific T-cell mediated IFN-γ responses to Twinrix® which in theory could provide effective immunity despite low anti-HBs titer. A total of 309 hepatitis B negative health care students and workers completed a standard Twinrix® vaccination schedule (0, 1 and 6 months). Depending on the vaccination response the participants were divided in to non-, low- and high responders according to anti-HBs titer (<10, <100 and >1000 mIU/mL respectively) two months after completed vaccination schedule. Blood samples from baseline and after vaccination from all non- and low-responders (23 participants) and the same number of high-responders were used for flow cytometric analyses of IL10 producing Bregs and T-cell mediated IFN-γ responses. A decrease in levels of IL10 producing Bregs was observed after vaccination in high responders compared to non- and low-responders. Compiling non-and low-responders against high-responders showed a lower T-cell mediated IFN-γ response at baseline in non-and low-responders when stimulated with Engerix® vaccine. In contrary no positive correlation between IL10 producing Bregs or IFN-γ positive T-cells and anti-HBs titer was observed. Hence this study cannot prove that levels of IL10 producing Bregs or IFN-γ positive T cell affect HBV vaccine response.

Assistance with the article: the authors would like to thank the 'Clinical Skills Development Service' in Brisbane and Clinton Henderson for their contribution in setting up the manikins used for the study, Cambell Smyth for his contribution in the CAD design of the device and the drawings presented in this article, Joanne Zuo for her contribution with the digital data analysis, Jose Medrano for his suggestions for the design of the study, and Sergio Lordao and Michael Minoza for their contribution taking the photos and video.Financial support and sponsorship: none.Conflicts of interest: JMA has created the concept and design of the Airway Shield and has filed an international patent for commercial use. JL and KS have no conflicts of interest to declare.