Assessment and treatment of muscle weakness in critically ill patients

Advances in intensive care medicine have dramatically improved survivalof critically ill (CI) patients.  This improved survival is, however, often associated with general deconditioning and muscle weakness.Early mobilization (e.g. bedside cycle ergometer) has been proven valuable in the treatment of CI patients even after hospital discharge. But no strength measures were proven to be reliable in CI patients. In the first study we found that handheld dynamometry, which is often used in deconditioned patients (e.g. Chronic Obstructive Pulmonary Disease (COPD) patients), is also a reliable tool on the intensive care unit (ICU).
Critically ill patients lose most of their muscle strength in the first few weeks on the ICU. Since they are mostly sedated in this period, active mobilization is not feasible. Neuromuscular electrical stimulation (NMES) is a treatment option in which no collaboration from the patient is needed to evoke a muscle contraction and thus could be potentially effective in the treatment of CI patients. Firstly we want to know if there was something known about electrical stimulation on the ICU. A review of the effectiveness of NMES on the ICU will give us more insight in this new treatment option. In this review we will also give attention to the stimulation parameters used in the different studies of NMES on the ICU, as these differ from the settings in other patient populations.
NMES is more difficult to perform on the ICU in comparison with healthy people. We were especially interested in knowing if it is possible to obtain a contraction with this method (as it is possible in other patient populations). In other publication about NMES on the ICU, the authors never mention if it was feasible to obtain a contraction in every patient. Also, since we are treating CI patients and this is a new method, we were also interested in whether or not it was a safe treatment on the ICU. In our research, we found that it was feasible in 48% of our patients. In CI patients with edema and in patients with sepsis, it was statistically significantly more difficult to obtain a contraction. There was absolutely no risk in performing the treatment. Blood pressure, heart rate, respiratory rate and oxygen saturation did not change during the treatment.
The results of NMES on the ICU in literature are ambiguous. Some authors find results in favor of NMES, others find no difference between the use of NMES and no NMES treatment. There are some explanationsfor these differences in results. Not all authors use the same outcome to draw the conclusion on the effectiveness of NMES. Some authors use ultrasound measurements of the quadriceps muscle, while others use circumference measures. Some authors dont measure muscle thickness and only perform strength measurements. Also, the timing of the treatment differs in different studies. Some authors treat patients in the acute phase, others in a chronic phase. Most of the studies were also performed on a small sample of CI patients (8-16 patients). We will include more patients to draw solid conclusions. Also, we will perform ultrasound measurementsand these will be combined with strength measures. In addition, we willtake biopsies in a subsample to investigate the effect of NMES on the molecular mechanisms of muscle breakdown in CI patients.