Diaphragmatic dysfunction in the intensive care unit: caught in the cross-fire between sepsis and mechanical ventilation

Accumulating evidence indicates that diaphragmatic weakness is common and frequently severe in mechanically ventilated patients. Supinski and Callahan now report that infection is a major risk factor for diaphragmatic weakness in this patient population. Importantly, they show that patients with the greatest levels of diaphragmatic dysfunction have a much poorer prognosis in terms of more prolonged ventilation as well as higher mortality. Mechanical ventilation itself has also been found to induce diaphragmatic weakness along with cellular changes resembling those found in sepsis. Future studies should be directed at understanding the interaction between sepsis and mechanical ventilation, and to developing therapeutic approaches that target their common cellular pathways implicated in diaphragmatic weakness.