Goal-directed haemodynamic therapy during general anaesthesia for noncardiac surgery: a systematic review and meta-analysis.

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 ratio=0.84; 95% confidence interval [CI], 0.64 to 1.09) and shorten length of stay (mean difference=-0.72 days; 95% CI, -1.10 to -0.35) 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. CONCLUSIONS: Goal-directed haemodynamic therapy during general anaesthesia might decrease mortality, hospital length of stay, and several postoperative complications. Only infectious postoperative complications and anastomotic leakage reached moderate certainty in the evidence.

Ventilation Strategies During General Anesthesia for Noncardiac Surgery: A Systematic Review and Meta-Analysis.

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.

Fraction of inspired oxygen during general anesthesia for non-cardiac surgery: Systematic review and meta-analysis.

BACKGROUND: Controversy exists regarding the effects of a high versus a low intraoperative fraction of inspired oxygen (FiO2 ) in adults undergoing general anesthesia. This systematic review and meta-analysis investigated the effect of a high versus a low FiO2 on postoperative outcomes. METHODS: PubMed and Embase were searched on March 22, 2022 for randomized clinical trials investigating the effect of different FiO2 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%) FiO2 . Risk of bias was intermediate for all trials. A high FiO2 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 -0.25 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. CONCLUSIONS: In adults undergoing general anesthesia for non-cardiac surgery, a high FiO2 did not improve outcomes including surgical site infections, length of stay, or mortality. However, the certainty of the evidence was assessed as low.

Pulmonary vasodilation during cardiopulmonary resuscitation - A randomized, controlled porcine study.

BACKGROUND: During resuscitation pulmonary artery pressure (PAP) increases. This reduces left ventricular filling, leading to decreased blood flow. Inhaled nitric oxide (iNO) produces selective pulmonary vasodilation. We hypothesized that iNO would lower PAP during resuscitation resulting in increased survival. METHODS: 30 pigs (40 kg) were subjected to cardiac arrest for 9.5 min after myocardial ischemia induced by coronary artery occlusion of the left anterior descending artery and ventricular fibrillation. During resuscitation, the pigs were randomized to 40 ppm iNO or placebo. The primary outcome was return of spontaneous circulation (ROSC). Pigs achieving ROSC underwent 4-hours intensive care. RESULTS: The ROSC rate was 9/14 (64%) in the control group and 11/16 (69%) in the iNO group (OR 1.2 95%CI [0.3;5.6], p > 0.99). There was no difference in diastolic aorta pressure/PAP ratio (mean difference -0.99 [95% CI: -2.33-0.36], p = 0.14). Mean pulmonary artery pressure was lower in the iNO group 60 and 120 min after ROSC (mean difference: -12.18 mmHg [95%CI: -16.94; -7.43] p < 0.01 and -5.43 [95%CI: -10.39; -0.46] p = 0.03). Troponin I levels in the iNO group were significantly higher 60 and 120 min after ROSC (mean difference: 266105 ng/l [95%CI: 6356; 525855] p = 0.045 and 420049 ng/l [95%CI: 136779; 703320], p = 0.004). The area at risk of the heart was 33% (SD 1) in controls and 34% (SD 1) in the iNO group. The infarct size divided by the area at risk was 55% (SD 3) in controls and 86% (SD 1) in the iNO group, p = 0.01. CONCLUSION: Application of iNO did not improve the rate of ROSC or hemodynamic function but increased myocardial injury.

Extracorporeal cardiopulmonary resuscitation for cardiac arrest: An updated systematic review.

OBJECTIVES: To provide an updated systematic review on the use of extracorporeal cardiopulmonary resuscitation (ECPR) compared with manual or mechanical cardiopulmonary resuscitation during cardiac arrest. METHODS: This was an update of a systematic review published in 2018. OVID Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched for randomized trials and observational studies between January 1, 2018, and June 21, 2022. The population included adults and children with out-of-hospital or in-hospital cardiac arrest. Two investigators reviewed studies for relevance, extracted data, and assessed bias. The certainty of evidence was evaluated using GRADE. RESULTS: The search identified 3 trials, 27 observational studies, and 6 cost-effectiveness studies. All trials included adults with out-of-hospital cardiac arrest and were terminated before enrolling the intended number of subjects. One trial found a benefit of ECPR in survival and favorable neurological status, whereas two trials found no statistically significant differences in outcomes. There were 23 observational studies in adults with out-of-hospital cardiac arrest or in combination with in-hospital cardiac arrest, and 4 observational studies in children with in-hospital cardiac arrest. Results of individual studies were inconsistent, although many studies favored ECPR. The risk of bias was intermediate for trials and critical for observational studies. The certainty of evidence was very low to low. Study heterogeneity precluded meta-analyses. The cost-effectiveness varied depending on the setting and the analysis assumptions. CONCLUSIONS: Recent randomized trials suggest potential benefit of ECPR, but the certainty of evidence remains low. It is unclear which patients might benefit from ECPR.