The combination of neuromuscular electrical stimulation (NMES), high protein supplementation (HPRO), and mobility and strength rehabilitation (PT) is associated with improved lower extremity muscle volume in mechanically ventilated patients in the intensive care unit (ICU), according to a study in Heart & Lung.
The randomized, pilot EXPRES (ClinicalTrials.gov Identifier: NCT02509520) trial compared the effects of the combination of PT, NMES, and HPRO with standard ICU care (SC) regarding change in muscle mass and clinical outcomes.
Participants were aged older than 50 years, were mechanically ventilated (≥24 hours), had a pre-admission Barthel Index score of 70 or higher, and were able to perform physical therapy testing before ICU admission.
The SC group received standard, condition-specific ICU medical management, including strength and range of motion exercises and different mobility exercises as tolerated. The intervention group participated in a multimodal rehabilitation program and SC physical therapy by the hospital rehabilitation services. Participants in the intervention group were seen twice a day for 30 minutes each, up to 5 days per week. NMES involved use of a wireless wearable functional electrical stimulation system.
Participants in the intervention group had an average of 5.6 additional PT sessions and 10 NMES sessions, and burned more calories (15.3±6.8 vs 20.1±7.5 kcal/kg; P =.05) and protein (0.8±0.4 vs 1.3±0.4 g/kg/d; P =.003) compared with the SC group
A total of 39 participants were enrolled from May 2016 to March 2018. Twenty-three were randomly assigned to SC (mean age, 62±9.3 years; 43% male) and 16 to the intervention (mean age, 62±9.3 years; 50% men). By day 14, 8 intervention group participants and 11 SC group participants received computed tomography.
The intervention and SC groups had similar muscle cross-sectional area (CSA) and volumes at baseline, and the changes in CSA and volume of the thighs and lower legs were comparable between the 2 groups at day 7. On day 14, the SC group lost more muscle in a comparison of thigh and lower leg volume vs the intervention group (thigh -21.0% vs -8.4%, P =.03; lower leg -15.3% vs -1.2%, P =.05).
SC participants also had greater muscle loss in the thigh CSA vs the intervention group, but it was not statistically significant (thigh -26.2% vs -13.8%, P =.08). For lower leg CSA, the SC group continued to lose muscle mass and the intervention group gained lower leg volume during the 14-day period (-15.3% vs 1.2%, P =.08).
The SC group had a negative nitrogen balance throughout, and the intervention group returned to a positive nitrogen balance on days 5, 9, and 14, with significant differences in nitrogen balance observed between the 2 groups on day 9.
The SC group had a higher proportion of participants test positive for delirium compared with the intervention group at all time points, although no significant differences occurred in Confusion Assessment Method score. No difference was found regarding ICU length of stay, and the SC group had a nonstatistically significant increase in mean days on the ventilator.
The researchers note that the decreased number of patients at the study endpoint reduces the statistical power of the analyses. Another limitation is the inability to compare individual modalities or other combinations of intervention including HPRO plus PT without NMES or with NMES alone. Furthermore, because the study allows for an additional physical therapy session in the intervention group, it is possible that it could have contributed to the positive results in muscle volume and CSA more than the addition of HPRO and/or NMES.
“The findings demonstrate the favorable effects of this intervention to attenuate lower extremity muscle loss in older, mechanically ventilated survivors admitted to a medical ICU,” stated the study authors wrote.
Verceles AC, Serra M, Davis D, et al. Combining exercise, protein supplementation and electric stimulation to mitigate muscle wasting and improve outcomes for survivors of critical illness—the ExPrES study. Heart Lung. Published online December 3, 2022. doi: 10.1016/j.hrtlng.2022.11.013