Preoperative HIIT beneficial to individuals undergoing major surgery

Patients scheduled to undergo major surgery appear to improve their cardiorespiratory fitness (CRF) with a preoperative high-intensity interval training (HIIT) program, which in turn reduces postoperative complications, according to a study.

For the study, researchers searched multiple online databases for randomized clinical trials and prospective cohort studies in which HIIT protocols were evaluated in adult patients undergoing major surgery. Thirty-four of the 589 screened studies met initial eligibility criteria.

Data were pooled according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.  The primary endpoint was change in CRF, as defined by either peak oxygen consumption (V̇o2 peak) or 6-Minute Walk Test (6MWT) distance. Secondary endpoints included postoperative complications; hospital length of stay (LOS); and changes in quality of life, anaerobic threshold, and peak power output.

A total of 12 eligible studies involving 832 patients were included in the meta-analysis. Pooled data showed HIIT was more beneficial than standard care in terms of CRF (V̇o2 peak, 6MWT, anaerobic threshold, or peak power output) and postoperative outcomes (complications, LOS, quality of life). However, the study results had significant heterogeneity.

There was moderate-quality evidence of a significant increase in V̇o2 peak in eight studies including 627 patients (cumulative mean difference, 2.59 mL/kg/min, 95 percent confidence interval [CI], 1.52–3.65; p<0.001) and moderate-quality evidence of a significant decrease in complications in eight studies including 770 patients (odds ratio, 0.44, 95 percent CI, 0.32–0.60; p<0.001).

HIIT showed no favourable effects on hospital LOS (p=0.07) compared with standard of care.

Overall, the analysis had a high degree of heterogeneity in study outcomes and a low risk of bias.