Functional recovery of chronically critically ill patients in the first days after discharge from the intensive care unit: Feasibility of the 6-minute step test

BACKGROUND: Survivors of chronic critical illness often experience weakness and functional dependence to various degrees after their intensive care unit (ICU) stay. Evaluating their functional status with the traditional six-minute walk test is challenging due to space constraints or patient intolerance. OBJECTIVE: Our aim was to evaluate the feasibility of using the six-minute step test (6MST) as a measure of functional capacity in chronically critically ill patients early after ICU discharge. METHODS: This prospective study was undertaken in a private Brazilian hospital. From July 2019 to July 2020, all chronically critically ill patients were asked to participate 48 hours after ICU discharge. On the day of study inclusion and a week later, those who consented underwent functional assessment comprised of the 6MST, peripheral muscle strength using handgrip strength (HGS), and mobility using the ICU mobility scale (IMS). RESULTS: A total of 40 patients were included. The 6MST was feasible in 40% on the first evaluation and 57% on the second. The median 6MST was 0 [0–5] on the first evaluation and 3.5 [0–7.75] on the second (P = 0.005). The median HGS increased from 11.50 [9.25–18] on the first evaluation to 14.5 [10–20] on the second (P = 0.006). The median IMS was 4.5 [3.25–7] on the first evaluation and 6 [3.25–7] on the second (P<0.001). Despite the significant improvement, all parameters measured remained well below normal. CONCLUSION: The 6MST was a feasible measure of functional capacity in chronically critically ill patients early after ICU discharge. Patients had functional capacity well below predicted values.