Intensive care unit-acquired weakness: Recent insights

Abstract

Intensive care unit-acquired weakness (ICU-AW) is a common complication in critically ill patients and is associated with a variety of adverse outcomes. These include the need for prolonged mechanical ventilation and ICU stay; higher ICU, in-hospital, and 1-year mortality; and increased in-hospital costs. ICU-AW is associated with multiple risk factors including age, underlying disease, severity of illness, organ failure, sepsis, immobilization, receipt of mechanical ventilation, and other factors related to critical care. The pathological mechanism of ICU-AW remains unclear and may be considerably varied. This review aimed to evaluate recent insights into ICU-AW from several aspects including risk factors, pathophysiology, diagnosis, and treatment strategies; this provides new perspectives for future research.

Keywords: Intensive care unit-acquired weakness; Mechanism; Muscle atrophy; Muscle weakness; Risk factor; Treatment.

Figure 1

Risk factors for ICU-AW. The identified factors were classified as modifiable and non-modifiable. ICU-AW: Intensive care unit-acquired weakness; SIRS: Systemic inflammatory response syndrome.

Figure 2

Mechanisms of ICU-AW. Multiple mechanisms involved in the regulation of ICU-AW include an imbalance between protein synthesis and degradation, dysfunction of mitochondria, alterations in the function of the sarcoplasmic reticulum, destruction of myofilament structure, neuropathy, abnormal electrical excitability, and other mechanisms such as impairment in muscle satellite cells. ICU-AW: Intensive care unit-acquired weakness; IIS: Insulin/IGF-1 signaling; UPS: Ubiquitin-proteasome system; ROS: Reactive oxygen species.