Effects of Preoperative Breathing Exercise on Postoperative Outcomes for Lung Cancer Patients Undergoing Curative Intent Lung Resection: A Meta-Analysis

OBJECTIVE To determine the benefits of preoperative breathing exercises on hospital length of stay (LOS), pneumonia, postoperative pulmonary complications (PPC), six-minute walk distance (6MWD), forced expiratory volume in 1 sec (FEV1), and health-related quality of life (HRQoL) in patients undergoing surgical lung cancer resection. DATA SOURCES PubMed, EMBASE, Web of Science Core Collection and Cochrane Central Register of Controlled Trials were comprehensively searched upon inception to March 2021. STUDY SELECTION Only studies including preoperative inspiratory muscle training (IMT) and/or breathing exercises compared to a non-training control group were included. The meta-analysis was done using Cochrane software for multiple variables including LOS, pneumonia, PPC, 6MWD, FEV1, mortality and HRQoL. DATA EXTRACTION Two authors extracted the data of the selected studies. The primary outcomes were LOS and PPC. DATA SYNTHESIS A total of 10 studies were included in this meta-analysis of which 8 studies had both IMT and aerobic exercise. Pooled data for patients who performed preoperative breathing exercises, compared to controls, demonstrated a decrease in LOS with a pooled mean difference (PMD) of -3.44 days (95%CI -4.14, -2.75, p<0.01). Subgroup analysis also demonstrated LOS was further reduced when breathing exercises were combined with aerobic exercise (Chi2 4.85 and p=0.03). Preoperative breathing exercises reduces pneumonia and PPCs with OR of 0.37 (95%CI 0.18,0.75, p<0.01) and 0.37 (95%CI 0.21,0.65, p<0.01), respectively. An increase in 6MWD of 20.2 m was noted in those performing breathing exercises (95%CI 9.12, 31.21, p<0.01). No significant differences were noted in FEV1, mortality nor HRQoL. CONCLUSIONS Preoperative breathing exercises reduced LOS and PPC and pneumonia and potentially improves 6MWD in patients undergoing surgical lung cancer resection. Breathing exercises in combination with aerobic exercise yielded greater reductions in LOS. Randomized clinical trials are needed to test the feasibility of introducing a preoperative breathing exercise program in this patient population.