Ultrasound: a novel translational tool to study diaphragmatic dysfunction in critical illness

The diaphragm has an essential role in spontaneous breathing in humans and animals. Extensive data obtained in animal models show a time-dependent atrophy and decreased force-generating capacity of the diaphragm during ventilation and sedation, both in vitro and in vivo (1). Underlying pathophysiological mechanisms, as studied mostly in ventilated rodents, comprise microvascular, electrical, biochemical, structural and metabolic alterations, interacting in a complex way and culminating in not only loss of muscle strength and diaphragm myofibril contractility but even muscle atrophy (2).