Experimental asynchrony to study self-inflicted lung injury

Patient self-inflicted lung injury may be associated with worse clinical outcomes and higher mortality. Patient-ventilator asynchrony is associated with increased ventilator days and mortality, and it has been hypothesised as one of the important mechanisms leading to patient self-inflicted lung injury. However, given the observational nature of the key studies in the field so far, the hypothesis that patient-ventilator asynchrony causes patient self-inflicted lung injury has not been supported by evidence yet. Wittenstein and colleagues present a novel approach that enables controlling patient-ventilator asynchrony in a pig model of acute lung injury, to investigate the patient-ventilator asynchrony and patient self-inflicted lung injury causality. Their results suggest that increased patient-ventilator asynchrony associated with poor clinical outcomes reported in observational trials could be a marker, rather than a cause of patient self-inflicted lung injury. These findings on their own are not sufficient to justify a greater tolerance of patient-ventilator asynchrony amongst clinicians, a change for which further experimental work and clinical evidence is needed.