Cardiopulmonary bypass (CPB) is necessary for most cardiac surgery, which may lead to postoperative lung injury. The objective of this paper is to systematically evaluate whether ventilation during CPB would benefit patients undergoing cardiac surgery. We searched randomized controlled trials (RCTs) through PubMed, Embase, and Cochrane Library from inception to October 2016. Eligible studies compared clinical outcomes of ventilation versus nonventilation during CPB in patients undergoing cardiac surgery. The primary outcome includes oxygenation index (PaO2/FiO2 ratio) or alveolar to arterial oxygen tension difference (AaDO2) immediately after weaning from bypass. The secondary outcomes include postoperative pulmonary complications (PPCs), shunt fraction (Qs/Qt), hospital stay, and AaDO2 4 hours after CPB. Seventeen trials with 1162 patients were included in this meta-analysis. Ventilation during CPB significantly increased post-CPB PaO2/FiO2 ratio (mean difference [MD] = 21.84; 95% confidence interval [CI] = 1.30 to 42.37; P = 0.04; I2 = 75%) and reduced post-CPB AaDO2 (MD = –50.17; 95% CI = –71.36 to –28.99; P <0.00001; I2 = 74%). Qs/Qt immediately after weaning from CPB showed a significant difference between groups (MD = –3.24; 95% CI = –4.48 to –2.01; P <0.00001; I2 = 0%). Incidence of PPCs (odds ratio [OR] = 0.79; 95% CI = 0.42 to 1.48; P = 0.46; I2 = 37%) and hospital stay (MD = 0.09; 95% CI = –23 to 0.41; P = 0.58; I2 = 37%) did not differ significantly between groups. Ventilation during CPB might improve post-CPB oxygenation and gas exchange in patients who underwent cardiac surgery. However, there is no sufficient evidence to show that ventilation during CPB could influence long-term prognosis of these patients. The beneficial effects of ventilation during CPB are requisite to be evaluated in powerful and well-designed RCTs.

BACKGROUND: The effect of anesthesia regimens on postoperative delirium after on-pump cardiac valve surgery is yet undetermined. This study aimed to evaluate the effect of volatile anesthesia compared with propofol-based total intravenous anesthesia (TIVA) on the occurrence of delirium after on-pump cardiac valve surgery. METHODS: This randomized clinical trial was conducted at a university academic hospital in China, from February 2019 to January 2021. Patients scheduled for on-pump cardiac valve surgery or combined valve with coronary artery bypass grafting (CABG) surgeries were randomly assigned to receive anesthesia maintenance with either a volatile anesthetic (sevoflurane or desflurane) or propofol-based TIVA. The primary outcome was the incidence of delirium during the first 7 days after surgery, assessed using the confusion assessment method for the intensive care unit (ICU). The secondary outcomes included duration of delirium, subtypes of delirium, 30-day mortality, pain score, major morbidity (including cerebral infarction, respiratory failure, and pneumonia), duration of mechanical ventilation, and lengths of ICU and hospital stay. The statistical analysis of the primary outcome variable was by Pearson’s χ² test. RESULTS: Among the 684 patients analyzed (mean age, 53.8 years; 381 [55.7%] women), 676 were assessed for the primary outcome. Postoperative delirium occurred in 63 of 337 (18.7%) patients receiving volatile anesthesia versus 76 of 339 (22.4%) patients receiving propofol-based TIVA (relative risk, 0.80; 95% confidence interval [CI], 0.55–1.16; P = .231). There were no significant differences between the groups in any of the secondary outcomes. CONCLUSIONS: Among patients undergoing on-pump cardiac valve surgery, anesthesia maintenance with a volatile agent did not result in significantly fewer occurrences of postoperative delirium than propofol-based TIVA.

Background: To determine whether maintaining ventilation during cardiopulmonary bypass (CPB) with a different fraction of inspired oxygen (FiO₂) had an impact on the occurrence of postoperative pulmonary complications (PPCs). Methods: A total of 413 adult patients undergoing elective cardiac surgery with CPB were randomly assigned into three groups: 138 in the NoV group (received no mechanical ventilation during CPB), 138 in the LOV group (received a tidal volume (V_T) of 3–4 ml/kg of ideal body weight with the respiratory rate of 10–12 bpm, and the positive end-expiratory pressure of 5–8 cmH₂O during CPB; the FiO₂ was 30%), and 137 in the HOV group (received the same ventilation parameters settings as the LOV group while the FiO₂ was 80%). Results: The primary outcomes were the incidence and severity of PPCs during hospitalization. The composite incidence of PPCs did not significantly differ between the NoV (63%), LOV (49%) and HOV (57%) groups (P = 0.069). And there was also no difference regarding the incidence of PPCs between the non-ventilation (NoV) and ventilation (the combination of LOV and HOV) groups. The LOV group was observed a lower proportion of moderate and severe pulmonary complications (grade ≥ 3) than the NoV group (23.1% vs. 44.2%, P = 0.001). Conclusion: Maintaining ventilation during CPB did not reduce the incidence of PPCs in patients undergoing cardiac surgery. Trial registration: Chinese Clinical Trial Registry ChiCTR1800015261. Prospectively registered 19 March 2018. http://www.chictr.org.cn/showproj.aspx?proj=25982

BACKGROUND: The effect of general anesthetics (propofol and volatile anesthetics) on pulmonary outcome after lung resection surgery with one-lung ventilation (OLV) is yet undetermined. We evaluated the effect of intravenous anesthesia (propofol) and volatile anesthesia (sevoflurane or desflurane) regimens on postoperative pulmonary complications (PPCs) in patients undergoing lung resection surgery. METHODS: This prospective, randomized controlled trial enrolled 555 adult patients scheduled for lung resection surgery with OLV. Participants were randomized to 1 of 3 general anesthetic regimens (propofol, sevoflurane, or desflurane). Standard anesthesia and ventilation protocols were followed in all groups. The primary outcome was a composite of PPCs in the first 7 postoperative days. Secondary outcomes included the severity of PPCs and major postoperative complications classification. Intergroup difference in the primary outcome was assessed for significance using the Pearson χ² test. RESULTS: Of 837 patients who were assessed for eligibility, 555 were randomized and 545 were analyzed. One hundred and seventy-nine patients were assigned to the propofol group, 182 in the sevoflurane group, and 184 in the desflurane group. The incidence of PPCs did not differ between the combined volatile anesthetics (sevoflurane and desflurane) group and the propofol group (21.9% vs 24.0%; odds ratio, 0.89; 95% confidence interval, 0.58-1.35; P = .570). The PPCs grade and Clavien-Dindo scores did not differ significantly across groups. CONCLUSIONS: In patients undergoing lung resection surgery with OLV, general anesthesia with volatile anesthetics (sevoflurane or desflurane) did not reduce PPCs compared with propofol. No difference in secondary outcomes was observed.