Acute respiratory distress syndrome, mechanical ventilation, and right ventricular function

PURPOSE OF REVIEW: To reiterate the effects of positive pressure ventilation on right ventricular (RV) function in acute respiratory distress syndrome (ARDS), to explain in which conditions acute cor pulmonale (ACP) may worsen prognosis, and to define an approach to protection of the right ventricle. RECENT FINDINGS: In unselected populations of ARDS patients, large studies have reported a 25% incidence of ACP. ACP has deleterious consequences, such as patent foramen ovale shunting and fewer ventilator-free days within the first 28 days. ACP may also worsen prognosis if not taken into account to adapt respiratory settings to RV function. ACP reflects the balance between lung recruitment and lung overdistension. To prevent ACP or to correct it, plateau pressure must be below 27-28 cmH2O, hypercapnia controlled, intrinsic positive end-expiratory pressure (PEEP) avoided, and a 'low' PEEP applied. Recent findings have suggested a negative correlation between the deleterious effect of PEEP on RV function and its ability to recruit the lung. SUMMARY: Routine RV function assessment leads to an approach to mechanical ventilation in ARDS patients designed for protection of the right ventricle. This approach called 'RV protective approach' must be associated with prone positioning, a method of ventilation that improves RV function.