Supporting small steps toward big innovations: the importance of rigorous pilot studies in critical care

Neuromuscular electrical stimulation in mechanically ventilated patients: a randomized, sham-controlled pilot trial with blinded outcome assessment

PURPOSE

The purpose of the study is to compare neuromuscular electrical stimulation (NMES) vs sham on leg strength at hospital discharge in mechanically ventilated patients.

MATERIALS AND METHODS

We conducted a randomized pilot study of NMES vs sham applied to 3 bilateral lower extremity muscle groups for 60 minutes daily in the intensive care unit (ICU). Between June 2008 and March 2013, we enrolled adults who were receiving mechanical ventilation within the first week of ICU stay and who could transfer independently from bed to chair before hospital admission. The primary outcome was lower extremity muscle strength at hospital discharge using Medical Research Council score (maximum, 30). Secondary outcomes at hospital discharge included walking distance and change in lower extremity strength from ICU awakening. Clinicaltrials.gov: NCT00709124.

RESULTS

We stopped enrollment early after 36 patients due to slow patient accrual and the end of research funding. For NMES vs sham, mean (SD) lower extremity strength was 28 (2) vs 27 (3), P = .072. Among secondary outcomes, NMES vs sham patients had a greater mean (SD) walking distance (514 [389] vs 251 [210] ft, P = .050) and increase in muscle strength (5.7 [5.1] vs 1.8 [2.7], P = .019).

CONCLUSIONS

In this pilot randomized trial, NMES did not significantly improve leg strength at hospital discharge. Significant improvements in secondary outcomes require investigation in future research.