Use of Neuromuscular Electrostimulation (NMES) for Treatment or Prevention of ICU-Associated Weakness

Survivors of critical illness frequently have significant, debilitating and persistent weakness after discharge from the intensive care unit (ICU). This weakness can persist for up to 4 years after ICU discharge. There are few interventions that have been successful in reducing or preventing weakness. Neuromuscular electrostimulation (NMES) therapy is beneficial in other populations of weak and functionally limited patients, such as those with chronic respiratory failure requiring mechanical ventilation, severe chronic obstructive pulmonary disease and end-stage congestive heart failure. We propose a randomized clinical trial to evaluate the efficacy of 60 minutes of NMES versus sham therapy, applied to the bilateral lower extremities, to reduce ICU-associated weakness in patients with acute respiratory failure. Our specific aims are to determine if NMES therapy will: 1) increase strength of the 3 treated lower extremity muscle groups (i.e., pretibial, triceps surae, and quadriceps), 2) improve important clinical outcomes (i.e., functional status, duration of mechanical ventilation, length of ICU and hospital stay, in-hospital mortality, and total hospital charges), 3) reduce critical illness myopathy as an etiology of weakness in clinically weak ICU patients. The investigators hypothesize that NMES therapy will reduce ICU-associated weakness, and improve clinical and functional outcomes. Additionally, the rates of critical illness myopathy as an etiology of weakness in clinically weak ICU patients will be lower in those receiving NMES versus sham therapy. Since there is no single test that is optimal for measuring muscle strength in the critically ill, the investigators will employ four non-invasive measures: manual muscle testing (MMT), hand held dynamometry (HHD), handgrip dynamometry (HGD), and maximal inspiratory pressure (MIP). With no existing therapeutic options available, our study explores the potential of NMES as a feasible intervention to reduce ICU-associated weakness.

Inclusion criteria

• 1 day of mechanical ventilation with an expectation of requiring ≥2 additional days of ICU stay in a Johns Hopkins Intensive Care Unit (ICU)

Exclusion criteria

• Unable to understand or speak English due to language barrier or cognitive impairment prior to admission
• Unable to independently transfer from bed to chair at baseline prior to hospital admission
• Known primary systemic neuromuscular disease (e.g. Guillian-Barre) at ICU admission
• Known intracranial process that is associated with localizing weakness (e.g. cerebral vascular accident) at ICU admission
• Transferred from another ICU outside of the Johns Hopkins system after >4 consecutive days of mechanical ventilation
• Moribund (i.e. >90% probability of patient mortality in the next 96 hours)
• Anticipated transfer to another ICU for care (e.g. awaiting organ transplantation and transfer to surgical ICU)
• Any pacemaker (e.g., cardiac, diaphragm) or implanted cardiac defibrillator
• Pregnancy
• Body mass index ≥35 kg/m2
• Any limitation in life support other than a sole no-CPR order
• Known or suspected malignancy in the legs
• Unable to treat or evaluate both lower extremities (e.g., bilateral amputation, bilateral skin lesions)
• ICU length of stay >7 days prior to enrollment