Low-Flow Anesthesia and Perioperative Pulmonary Outcomes: A Systematic Review and Meta-Analysis

Abstract

Background: There is a growing interest in the use of low-flow anesthesia in perioperative practice as a strategy to preserve pulmonary function, use less anesthetic gases and minimize pollution of the environment. Though, the relative effectiveness of low-flow compared to high-flow anesthesia about postoperative pulmonary outcomes has not been clearly delineated.

Objective: The present study aimed to evaluate the effects of low-flow anesthesia on postoperative pulmonary function and respiratory complications compared with conventional high-flow anesthesia techniques.

Methods: A systematic review and meta-analysis of published literature on pulmonary effects of low-flow anesthesia was performed. After a comprehensive search of databases, studies were screened for inclusion by predefined criteria for evaluation of pulmonary effects. Meta-analysis of pulmonary data postoperatively, incidence of atelectasis, respiratory stability, and perioperative data was analyzed with synthesis of pooled mean difference and risk ratios and heterogeneity.

Results: Meta-analysis revealed that low-flow anesthesia resulted in statistically significant better postoperative pulmonary function, In particular postoperative preserve values of FEV1, than did high-flow anesthesia. The incidences of postoperative atelectasis were also lower, and perioperative rapid respiratory stabilization was more evident in low-flow groups than in high-flow group. Subgroup analysis based on various types of surgery did not alter these pulmonary benefits with low-flow anesthesia. On top of that, low-flow anesthesia could Really decrease the consumption of anesthetic gases and improve total cost saving for patients of different age, weight, and ASA class without compromising patient safety. Overall heterogeneity among the included trials was moderate, indicating the reliability of study data synthesis.

Conclusion: Evidence shows that low-flow anesthesia may be a safe and effective anesthetic technique to optimize postoperative pulmonary function and decrease respiratory complications. The decreased cost and environmental advantages of low-flow techniques provide additional incentives for its regular use to optimize perioperative management. Large multicenter trials are needed to develop robust clinical guidelines and evaluate long-term outcomes.