Effects of the Level and Duration of Mobilization Therapy in the Surgical ICU on the Loss of the Ability to Live Independently: An International Prospective Cohort Study

Abstract

Objectives: It is unclear whether early mobilization in the surgical ICU helps improve patients' functional recovery to a level that enables independent living. We assessed dose of mobilization (level + duration). We tested the research hypotheses that dose of mobilization predicts adverse discharge and that both duration of mobilization and maximum mobilization level predict adverse discharge.

Design: International, prospective cohort study.

Setting: Study conducted in five surgical ICUs at four different institutions.

Patients: One hundred fifty patients who were functionally independent before admission (Barthel Index ≥ 70) and who were expected to stay in the ICU for greater than or equal to 72 hours.

Interventions: None.

Measurements and main results: Mobilization was quantified daily, and treatments from all healthcare providers were included. We developed and used the Mobilization Quantification Score that quantifies both level and duration of mobilization. We assessed the association between the dose of mobilization (level + duration; exposure) and adverse discharge disposition (loss of the ability to live independently; primary outcome). There was wide variability in the dose of mobilization across centers and patients, which could not be explained by patients' comorbidity or disease severity. Dose of mobilization was associated with reduced risk of adverse discharge (adjusted odds ratio, 0.21; 95%CI, 0.09-0.50; p < 0.001). Both level and duration explained variance of adverse discharge (adjusted odds ratio, 0.28; 95% CI, 0.12-0.65; p = 0.003; adjusted odds ratio, 0.14; 95% CI, 0.06-0.36; p < 0.001, respectively). Duration compared with the level of mobilization tended to explain more variance in adverse discharge (area under the curve duration 0.73; 95% CI, 0.64-0.82; area under the curve mobilization level 0.68; 95% CI, 0.58-0.77; p = 0.10).

Conclusions: We observed wide variability in dose of mobilization treatment applied, which could not be explained by patients' comorbidity or disease severity. High dose of mobilization is an independent predictor of patients' ability to live independently after discharge. Duration of mobilization sessions should be taken into account in future quality improvement and research projects.

Trial registration: ClinicalTrials.gov NCT03196960.

Conflict of interest statement

Dr. Schaller’s institution received funding from Merck Sharp and Dohme (MSD, Haar, Germany), European Society of Intensive Care Medicine (ESICM, Brussels, Belgium), Fresenius (Germany), Liberate Medical LLC (Crestwood, KY), Stimit AG (Aktiengesellschaft, english: corporation, Nidau, Switzerland); he received funding from Technical University of Munich, Munich, Germany, from national (e.g., Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin) and international (e.g., ESICM) medical societies (or their congress organizers) in the field of anesthesiology and intensive care and Alphabeth, Rhön-Klinikum AG, and Siemens AG; and he received nonfinancial support from Bavarian Medical Association, all outside the submitted work. Dr. Blobner received funding from MSD, Grünenthal, and GE Healthcare. Dr. Eikermann’s institution received funding from Jeff and Judy Buzen, and he received support for article research from the National Institutes of Health. The remaining authors have disclosed that they do not have any potential conflicts of interest.

Copyright © 2021 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.

Figures

Fig. 1:

Flow diagram of patients in study.

Fig. 2:

Mobilization Quantification Score used to quantify dose of mobilization. For each mobilization session, the highest mobilization level was identified and multiplied by the corresponding unit count to arrive at the dose of mobilization. ICU mobility scale adapted with permission from Carol Hodgson.

Fig. 3:

Variability in the dose of mobilization. A Predicted (based on objective criteria; propensity score for high dose of mobilization [x axis]) versus observed dose of mobilization (y axis). Box plot (median, interquartile range, 10th and 90th, outer fence) represents tertiles of the propensity score, which included the following variables: age, sex, Charlson Comorbidity Index, Glasgow Coma Scale at enrollment, Acute Physiology and Chronic Health Evaluation II score at enrollment, American Society of Anesthesiologists physical status, Procedural Severity Score for morbidity, days of sedation, days of ventilation, days with vasopressor treatment, mean opioid dose. The variability (variance) in observed dose of mobilization was significantly higher in patients presenting with a high predicted probability of receiving a high dose of mobilization. *pB Variability in dose of mobilization based on study center. Dose of mobilization (level + duration) differed across study centers and was significantly higher in US centers compared with the European centers. Dose of mobilization also differed significantly between centers within the same country (US). **p