Inactivity May Identify Older Intensive Care Unit Survivors at Risk for Post-Intensive Care Syndrome

Abstract

Background: Older adults (≥age 65) admitted to an intensive care unit (ICU) are profoundly inactive during hospitalization. Older ICU survivors often experience life-changing symptoms, including cognitive dysfunction, physical impairment, and/or psychological distress, which are components of post-intensive care syndrome (PICS).

Objectives: To explore trends between inactivity and symptoms of PICS in older ICU survivors.

Methods: This study was a secondary analysis of pooled data obtained from 2 primary, prospective, cross-sectional studies of older ICU survivors. After ICU discharge, 49 English- and Spanish-speaking participants who were functionally independent before admission and who had received mechanical ventilation while in the ICU were enrolled. Actigraphy was used to measure post-ICU hourly activity counts (12:00 AM to 11:59 PM). Selected instruments from the National Institutes of Health Toolbox and Patient-Reported Outcomes Measurement Information System were used to assess symptoms of PICS: cognitive dysfunction, physical impairment, and psychological distress.

Results: Graphs illustrated trends between inactivity and greater symptom severity of PICS: participants who were less active tended to score worse than one standard deviation of the mean on each outcome. Greater daytime activity was concurrently observed with higher performances on cognitive and physical assessments and better scores on psychological measures.

Conclusions: Post-ICU inactivity may identify older ICU survivors who may be at risk for PICS and may guide future research interventions to mitigate symptom burden.

Figure

Twenty-four hours of hourly activity counts by scores on each outcome measure. Visuospatial attention score: National Institutes of Health (NIH) Toolbox Cognition Battery Flanker Inhibitory Control and Attention Test fully corrected T score. Worse than 1 SD below the mean=T score less than 40; within 1 SD of the mean=T score greater than 40. Higher scores indicate better cognitive performance related to attention. Cognitive flexibility score: NIH Toolbox Cognition Battery Dimensional Change Card Sort Test fully corrected T score. Worse than 1 SD below the mean = T score less than 40; within 1 SD of the mean=T score greater than 40. Higher scores indicate better cognitive performance related to cognitive flexibility. Grip strength score: NIH Toolbox Motor Battery Grip Strength Test fully corrected T score. Worse than 1 SD below the mean=T score less than 40; within 1 SD of the mean=T score greater than 40. Higher scores indicate better physical performance related to dominant hand grip strength. Dexterity score: NIH Toolbox Motor Battery 9-Hole Pegboard Dexterity Test fully corrected T score. Worse than 1 SD below the mean=T score less than 40; within 1 SD of the mean=T score greater than 40. Higher scores indicate better physical performance related to dominant hand dexterity. Depression score: PROMIS Emotional Distress–Depression Short Form 8a. Worse than 1 SD above the mean=T score greater than 60; within 1 SD of the mean=T score less than 60. Higher scores indicate worse seve rity of depression. Anxiety score: PROMIS Emotional Distress–Anxiety Short Form 8a. Worse than 1 SD above the mean=T score greater than 60; within 1 SD of the mean=T score less than 60. Higher scores indicate worse severity of anxiety. Hourly activity counts: Mean activity counts averaged hourly during a 24-hour period as measured by wrist actigraphy. Higher activity counts indicate greater activity.