Patient Self-Inflicted Lung Injury: What the Intensivist Needs to Know

Abstract

Nowadays, clinicians are familiar with the concept of VILI (ventilator induced lung injury). Its main mechanical components are volotrauma and atelectrauma. Volotrauma depends on both the tidal volume and the pulmonary volume available for the ventilation. On both conceptual and experimental standpoints, patient’s spontaneous respiratory effort may generate the same volume than the ventilator. Therefore, the patient’s inspiratory effort may lead to the same risk of volotrauma. Furthermore, recent experimental data has reported the additional physiological consequences of important respiratory effort, especially in case of underlying lung injury (e.g., “pendelluft”, atelectrauma of dependent areas, increase in transmural vascular pressure). These physiological effects are prone to aggravate pre-existing pulmonary lesions, worsening even more gas exchange and respiratory mechanics, which stimulates more strenuously respiratory drive. This vicious circle characterized by patient’s self-inflicted lesions has been recently identified as P-SILI (patient self-inflicted lung injury). Recognition of clinical scenario at risk of P-SILI allows tailoring therapeutic strategy. Sometimes, controlled mechanical ventilation may then be considered as a protective treatment.