Use of Surface Electromyography to Measure Muscle Fatigue in Patients in an Acute Care Hospital.

BACKGROUND: Functional outcomes with early rehabilitation in the acute care setting have improved; however, an improved understanding of muscle fatigue using surface electromyography (sEMG) is warranted to better guide patient-centered exercise prescription. OBJECTIVES: The objectives of this study were to assess the safety and feasibility of collecting sEMG at the acute care bedside and to determine differences in muscle fatigue during isometric and dynamic submaximal contractions among patients in the hospital, healthy younger participants, and healthy older participants. DESIGN: The study used an observational cohort design. METHODS: There were 37 participants. Median frequency (Fmed) of the myoelectric signal of the quadriceps femoris muscles and time to task failure (TTTF) were measured using sEMG during an isometric and dynamic fatiguing contraction. Primary analysis compared TTTF between groups for both types of contractions. Secondary analysis compared Fmed at initiation and termination of fatiguing contraction. RESULTS: High-quality sEMG measures were safe and feasible to collect at the acute care bedside with no adverse events. There was a statistically significant difference in TTTF between groups after isometric and dynamic contractions; hospitalized patients fatigued faster than healthy younger and healthy older participants after both contractions. With the exception of the vastus lateralis during a dynamic contraction in healthy younger and hospitalized patients, there was a statistically significant difference between Fmed at initiation and termination of contraction, indicating that subjects' muscles did truly fatigue. LIMITATIONS: A limitation of the study was the small sample size of patients who were hospitalized without matched controls. CONCLUSIONS: sEMG is a lab quantitative technique that was found to be safe and feasible to assess muscle fatigue in the acute care environment. The protocol yielded similar results to previously published literature for healthy younger and healthy older people. Further research is needed to better understand how to integrate sEMG findings into patient-centered exercise prescriptions.

Physical rehabilitation of patients in the intensive care unit requiring extracorporeal membrane oxygenation: a small case series.

BACKGROUND AND PURPOSE: Neuromuscular weakness and impaired physical function are common and long-lasting complications experienced by intensive care unit (ICU) survivors. There is growing evidence that implementing rehabilitation therapy shortly after ICU admission improves physical function and reduces health care utilization. Recently, there is increasing interest and utilization of extracorporeal membrane oxygenation (ECMO) to support patients with severe respiratory failure. Patients receiving ECMO are at great risk for significant physical impairments and pose unique challenges for delivering rehabilitation therapy. Consequently, there is a need for innovative examples of safely and feasibly delivering active rehabilitation to these patients. CASE DESCRIPTION: This case report describes 3 patients with respiratory failure requiring ECMO who received physical rehabilitation to illustrate and discuss relevant feasibility and safety issues. OUTCOMES: In case 1, sedation and femoral cannulation limited rehabilitation therapy while on ECMO. In the 2 subsequent cases, minimizing sedation and utilizing a single bicaval dual lumen ECMO cannula placed in the internal jugular vein allowed patients to be alert and participate in active physical therapy while on ECMO, illustrating feasible rehabilitation techniques for these patients. DISCUSSION: Although greater experience is needed to more fully evaluate the safety of rehabilitation on ECMO, these initial cases are encouraging. We recommend systematically and prospectively tracking safety events and patient outcomes during rehabilitation on ECMO to provide greater evidence in this area.