A COMPARISON OF ISOLATION AND SPONTANEOUS VENTILATION FOR LUNG MANAGEMENT DURING THORACIC SURGERY: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Introduction General anaesthesia, mechanical ventilation with lung isolation using a double-lumen endobronchial tube or bronchial blocker, has been the standard for lung management during thoracic surgery for over 80 years. However, there has been increasing popularity for avoiding lung isolation and maintaining spontaneous ventilation for video assisted thoracoscopic surgery (VATS) both with patients conscious using regional anaesthesia and unconscious using general anaesthesia. Many benefits of spontaneous ventilation over the traditional approach have been proposed. We hypothesised that spontaneous ventilation would be significantly more efficient that lung isolation for thoracic surgery. The primary aim of this study was to compare the duration of hospital stay in patients undergoing thoracic surgery with lung isolation or spontaneous ventilation for lung management. Secondary aims were the durations of anaesthesia, global in-operating room duration and overall hospital cost. Methods Systematic search of PubMed, OVID/Embase and Google Scholar from January 2000 - October 2020 was conducted using predetermined inclusion criteria. Bias was assessed using the Cochrane screening method. Each lung management technique was segmented into randomised controlled trials (RCTs) and observational studies and analysed both separately and together. Meta-analysis using the Cochrane RevMan5 software was conducted and findings summarised as forest plots. Mean and 95% confidence intervals were compared alongside assessment of probability and heterogeneity. Results The literature search identified 649 studies, of which only 23 fulfilled the entry criteria, and these included a total of 2,564 patients. The duration of hospital stay was significantly shorter for spontaneous ventilation than lung isolation (mean: -0.78 days; 95% CI 1.17 - 0.38) in all studies and in RCTs (mean: -0.88 days; 95% CI 1.1 - 0.65). The duration of anaesthesia was significantly shorter in spontaneous ventilation for all studies (mean: -10.87 minutes; 95% CI 9.3 - 12.43) and for RCTs (mean: -13.19 minutes; 95% CI 11.18 - 15.2). Similarly, global in operating room duration was shorter using spontaneous ventilation for all studies (mean: -33.31 minutes; 95% CI 23.57 - 43.04) and for RCTs (mean: -31.77 minutes; 95% CI 28.49 - 35.05). No statistically significant difference was found between hospital cost for the two techniques but when only RCTs were analysed, spontaneous ventilation was associated with a lower cost (mean: €990; 95% CI €760-1220). Discussion When compared to the traditional technique of lung isolation under general anaesthesia for thoracic surgery, techniques using spontaneous ventilation either under regional or general anaesthesia, were associated with shorter durations of hospital stay and anaesthesia as well as time spent in the operating room. In addition, hospital costs may also be less expensive using spontaneous ventilation.