Fig. 1From: Strategies to optimize respiratory muscle function in ICU patientsProposed scheme of pathophysiologic pathways in the development of respiratory muscle weakness during critical illness. Oxidative stress [89], inflammation [71, 74], increased nuclear factor (NF)-κB activity [90], and mechanical unloading [10, 11] have been proposed to initiate respiratory muscle weakness. These initiators can result in contractile protein becoming dysfunctional [4], decreased synthesis [14, 15], or muscular autophagy [12]. Oxidative stress and inflammatory pathways can activate caspases and calpains [89, 91], thereby delivering substrates for the ubiquitin-proteasome [10, 11, 92], which further degrades contractile proteinsBack to article page