Vasoplegic syndrome after open heart surgery

A new form of postperfusion manifestation is detailed, a vasoplegic syndrome presenting in the postoperative period after cardiopulmonary bypass (CPB) heart surgery.

This retrospective study included sixteen patients who underwent cardiovascular surgery using CPB and exhibited clinical and hemodynamic features compatible with vasoplegic syndrome. The technique of CPB was hypothermic (28 degrees C) in 15 and normothermic in 1 patient, and hypothermic blood cardioplegia was employed in all patients, except 1. The mean CPB time was 121 minutes, ranging from 80 to 210 minutes.

The patients presented a severe feature comprising hypotension, tachycardia, normal or elevated cardiac output, low systemic vascular resistance and decreased filling pressures. Fluid administration alone was not capable of restoring hemodynamic parameters. Physical examination revealed normal capillary filling at the extremities although oliguria and hypotension were observed. These patients needed a high dosage of vasoconstrictor drugs (norepinephrine) for blood pressure control but even high dose norepinephrine did not produce the classical situation of cool extremities and weak peripheral pulses, with increased morbidity and mortality. Severe systemic complications could develop if the vasoplegic syndrome persisted 36-48 hours after its onset. All patients, except 3, presented associated postoperative complications and 4 patients died. The characteristics of vasoplegic syndrome are similar to those observed in septic shock, where the alterations are mediated by cytokines and tumor necrosis factor-alpha.

The appearance of vasoplegic syndrome augmented operative morbidity with a consequent increased risk to the patient in the early postoperative period.