Muscle atrophy in critically ill patients : a review of its cause, evaluation, and prevention

Abstract

Critically ill patients exhibit prominent muscle atrophy, which occurs rapidly after ICU admission and leads to poor clinical outcomes. The extent of atrophy differs among muscles as follows: upper limb: 0.7%-2.4% per day, lower limb: 1.2%-3.0% per day, and diaphragm 1.1%-10.9% per day. This atrophy is caused by numerous risk factors such as inflammation, immobilization, nutrition, hyperglycemia, medication, and mechanical ventilation. Muscle atrophy should be monitored noninvasively by ultrasound at the bedside. Ultrasound can assess muscle mass in most patients, although physical assessment is limited to almost half of all critically ill patients due to impaired consciousness. Important strategies to prevent muscle atrophy are physical therapy and electrical muscular stimulation. Electrical muscular stimulation is especially effective for patients with limited physical therapy. Regarding diaphragm atrophy, mechanical ventilation should be adjusted to maintain spontaneous breathing and titrate inspiratory pressure. However, the sufficient timing and amount of nutritional intervention remain unclear. Further investigation is necessary to prevent muscle atrophy and improve long-term outcomes.

Early Initiation of Awake Veno-Venous Extracorporeal Membrane Oxygenation Can Attenuate Muscle Atrophy and Weakness in Acute Respiratory Distress Syndrome

“…In this patient, the extent of atrophy was lower than in a previous report (13.0% vs. 20.7% on day 7), although the patient’s severity was the same (APACHE II [Acute Physiology And Chronic Health Evaluation II] score of 27 vs. 27.5 [23.0-29.3]) [ 11 ]. Moreover, this patient was treated with steroids, which is a risk factor for muscle atrophy [ 6 ]. Rehabilitation is important to prevent muscle atrophy [ 6 ].…”

“…Moreover, this patient was treated with steroids, which is a risk factor for muscle atrophy [ 6 ]. Rehabilitation is important to prevent muscle atrophy [ 6 ]. In this case, the patient was safely mobilized during ECMO treatment.…”

“…Diaphragm atrophy occurs in around 60% of mechanically ventilated patients [ 8 ]. Prevention of diaphragm atrophy is gaining increased attention with diaphragm-protective ventilation, but no study clearly reported the prevention of diaphragm atrophy [ 6 ]. Avoiding high inspiratory pressure is promising in an observational study [ 14 ].…”

“…In spite of the catabolism, the Medical Research Council (MRC) score was maintained at 59, 60, 58, and 60 on days 2, 3, 5, and 7, respectively. Furthermore, the patient did not experience ICU-acquired weakness [ 6 ].…”

“…Although mobilization is important in patients with ARDS, sedation hampers the active mobilization of patients. Moreover, discontinuation of spontaneous breathing to prevent lung injury is deleterious to the diaphragm muscle [ 6 ]. Therefore, lung protective strategies may lead to prominent limb and diaphragm muscle atrophy, leading to prolonged physical dysfunction.…”