Patient-important outcomes reported in randomized clinical trials (RCTs) of neuromuscular electrical stimulation (NMES) in mechanically ventilated patients: a systematic methodologic review

Article type
Authors
Kho ME1, Duffett MC2, Koo KK3, Dodek P4, Herridge MS5, Lamontagne F6, Needham DM7, Cook DJ8
1School of Rehabilitation Science, McMaster University, Canada; Department of Physical Medicine and Rehabilitation, Johns Hopkins University, USA
2Clinical Epidemiology and Biostatistics, McMaster University, Canada
3Department of Medicine and Division of Critical Care, University of Western Ontario, Canada
4Center for Health Evaluation and Outcome Sciences, St. Paul’s Hospital and University of British Columbia, Canada
5Interdepartmental Division of Critical Care Medicine, University of Toronto, Canada
6Centre de Recherche Clinique E´tienne-Le Bel, Université de Sherbrooke, Sherbrooke, Canada;
7Division of Pulmonary & Critical CareMedicine, Department of Physical Medicine and Rehabilitation, Johns Hopkins University, USA
8Medicine and Clinical Epidemiology and Biostatistics, McMaster University, Canada
Abstract
Background: NMES is an emerging rehabilitation therapy to prevent or reduce intensive-care unit acquired weakness.

Objectives: To contrast the outcomes reported in RCTs of NMES in mechanically ventilated patients against authors’ interpretations of NMES effectiveness and its role in clinical practice.

Methods: We searched MEDLINE, EMBASE, LILACS, CINAHL, SCOPUS, and Web of Science for RCTs of NMES in mechanically ventilated patients. Independently, in duplicate we identified studies and abstracted descriptive data. We classified outcomes according to the International Classification of Function: body structure (e.g., protein turnover, muscle size), body function (e.g., muscle strength), activity (e.g., walking), and participation (e.g., return to work). We also identified safety and feasibility outcomes and the authors’ interpretations about NMES effectiveness and its role in clinical practice through textual assessment of study conclusions.

Results: Of 428 citations, we identified 13 unique RCTs; 5 of these were pilot trials. Seven studies randomized patients by treatment group, 4 randomized by body side, and 2 were crossover studies. The median [minimum, maximum] numbers of patients enrolled and evaluated per study were 19 [7, 142] and 15 [7, 52], respectively. Authors reported 33 different outcomes (Table 1), with a median [interquartile range] of 5 [3, 6] per study. Most studies reported measures of body structure (n = 11) or function (n = 7); only 2 reported activity, and none reported participation. Authors reported safety, feasibility, and other outcomes in only 6, 5, and 5 studies, respectively. Most authors [10 (78%)] concluded that NMES was an effective intervention and half [7 (54%)] suggested that NMES could be used in clinical practice. Of all favorable conclusions regarding effectiveness or usefulness in clinical practice, only 2 studies reported measures of activity.

Conclusions: There are at least 13 RCTs of NMES in critical care, but these studies are small and include few patient-important outcomes. To inform clinical practice, more studies reporting patient-important outcomes are needed.