Association Between Delays in Mechanical Ventilation Initiation and Mortality in Patients With Refractory Cardiogenic Shock
Sean van Diepen, Judith S. Hochman, Amanda Stebbins, Carlos L. Alviar, John H. Alexander, Renato D. Lópes
Abstract
Acute myocardial infarction (MI) is complicated by cardiogenic shock (CS) in 4% to 10% of patients, and contemporary mortality rates range from 31% to 51%. 1 A common sequela of CS is an elevated end-diastolic pressure leading to pulmonary congestion, and mechanical ventilatory (MV) support is required in up to 88% of patients. 2 Positive end-expiratory pressure (PEEP) imparts favorable cardiovascular hemodynamic changes in patients with CS and reduced left ventricular (LV) function. Positive end expiratory pressure lowers pulmonary wedge pressure, LV afterload, myocardial oxygen demand, work of breathing, and improves cardiac index and oxygenation. 3 Consequently, the timely initiation of MV in this population could theoretically attenuate physiologic deterioration or the ischemic cascade and improve outcomes; however, to our knowledge, the association between timing of MV initiation and mortality in patients with CS has not been described.