Investigating inpatient rehabilitation outcomes of patients with intensive care unit-acquired weakness, and identifying comorbidities associated with unfavorable outcomes

Introduction: Data are consistent on the benefits of inpatient rehabilitation for intensive care unit-acquired weaknesses (ICUAW), including critical illness myopathy, critical illness polyneuropathy, critical illness polyneuromyopathy, and disuse atrophy. This study focuses on the effects of inpatient rehabilitation on patients with ICUAW, specifically those with a clinical pattern of proximal muscle weakness and sensory sparing.

Objectives: To evaluate the impact of inpatient rehabilitation on patients with ICUAW versus other medically complex patients, and to identify comorbidities associated with poor rehabilitation outcomes.

Design: Retrospective cohort study.

Setting: Institutional, inpatient rehabilitation hospital.

Patients: Two hundred seventy adult patients (≥18 years) divided into two groups: diagnosis of ICUAW (N = 55) or otherwise medically complex (N = 215), and admitted under the care of one physiatrist.

Interventions: Not applicable.

Main outcome measures: For all patients we compared functional independence measure (FIM) gain, FIM efficiency, rehabilitation length of stay (RLOS), discharge disposition, and major medical comorbidities.

Results: Patients with ICUAW had significantly greater FIM gain (P = .015) and RLOS (P = .02). There was no significant difference in FIM efficiency (P = .15). Patients with ICUAW had a significantly lower odds of acute hospital transfer (odds ratio [OR] = 0.52, with 95% confidence interval [CI] 0.47, 0.58) and skilled nursing facility discharge (OR = 0.19, with 95% CI 0.038, 0.95). However, patients with ICUAW did have a higher percent of acute hospital transfers than other medically complex patients (P = .017). In addition, patients with ICUAW were more medically complex, as evidenced by a significantly higher Charlson Comorbidity Index (P < .001), prevalence of anemia (P < .001), atrial fibrillation (P = .009), obstructive sleep apnea (P = .018), and bacteremia (P = .041).

Conclusions: Patients with ICUAW with a clinical pattern of proximal muscle weakness and sensory sparing benefit from inpatient rehabilitation as evidenced by FIM gain and high home discharge rate. However, they have multiple medical comorbidities, which require judicious medical management and may contribute to a longer RLOS.