Effect of inspiratory muscle training on respiratory muscle strength, post-operative pulmonary complications and pulmonary function in abdominal surgery- Evidence from systematic reviews.

Introduction Postoperative pulmonary complications (PPCs) following abdominal surgery are common in patients owing to patient-related and procedure-related risk factors. Inspiratory Muscle Training (IMT) along with various chest physiotherapy manipulations and adjuncts have been proven to reduce PPCs. Current evidence suggests that IMT proves beneficial in reducing PPCs without additional management in varying types of surgeries.  The objective of this review was to synthesize the findings from systematic reviews that evaluate the effectiveness of IMT on abdominal surgery and assess their methodological quality. Methods This review was formed following PRISMA guidelines (PROSPERO Registration number: CRD42020177876, OSF registry: DOI 10.17605/OSF.IO/K8NGV). A comprehensive search strategy identifying the effectiveness of IMT on abdominal surgery was developed using electronic databases such as PubMed, Cochrane database of a systematic review, and ClinicalKey. Methodological quality assessment was done using AMSTAR 2 tool. Data on characteristics of intervention and outcome measures were extracted. Results The search yielded 1249 articles, out of which 4 systematic reviews and meta-analysis; reviewing 9 randomized controlled trials; met the inclusion criteria. The most-reported outcome measures were respiratory muscle strength, PPCs, and pulmonary function tests. The overall quality of systematic reviews reported was high. The results for meta-analysis conducted on outcome measure PPCs, i.e., atelectasis and pneumonia reported RR=0.40 (95%CI 0.19 to 0.88), I ² =0%, and RR=0.41 (95%CI 0.41 to 1.19), I ² =0% respectively and maximum inspiratory pressure was MD=4.97, (95% CI -5.07 to 15.01), I ² = 53%. Conclusions The review concluded that IMT is a beneficial intervention when given 2 weeks before surgery for a minimum of 15 minutes in reducing PPCs. However, factors concerning breathing cycles, respiratory flow, and rest interval should be observed for better management.