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

Abstract

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.