Early postoperative 6-minute walk test in cardiac surgery patients: an observational study assessing safety, feasibility, and predictors of completion in India.

BACKGROUND: Early mobilization after cardiac surgery is crucial for enhancing recovery, minimizing complications, and promoting timely discharge. The 6-minute walk test (6MWT) is a validated measure of functional capacity; however, its use during the early postoperative period-particularly in Intensive care Unit (ICU) settings in India-remains underexplored. This study assesses the safety, feasibility, and functional performance outcomes of the 6MWT administered on postoperative days (PODs) 2 to 4 and identifies factors associated with test completion.

METHODS: A cohort-based observational study was conducted in a tertiary care ICU between June and September 2021. In total, 150 cardiac surgery patients aged 30-70 years were enrolled. Inclusion required hemodynamic stability, no vasopressor/inotropic support, and ambulation from POD 2. The 6MWT was administered per the American Thoracic Society guidelines. Clinical, demographic, and physiological parameters were recorded and analyzed using descriptive statistics, paired t-tests, and regression analyses.

RESULTS: Of the 150 patients, 140 completed the test. The mean age was 52±14 years, and 75% of participants were male. Mean walking distances improved from 78.14 m (21.7% of predicted) on POD 2 to 193.51 m (53.75%) on POD 4. Completion rates increased from 40.0% to 99.2%. Physiological responses remained within safe limits, and no serious adverse events occurred. The regression analyses identified education, diet, and oxygen saturation as positive predictors and comorbidities, being female, oxygen use, and physical occupation as negative predictors.

CONCLUSIONS: The 6MWT is a safe, feasible, and informative tool for assessing early functional recovery in stable post-cardiac surgery ICU patients to aid individualized rehabilitation and discharge planning.