Vasopressin therapy for vasoplegic syndrome following cardiopulmonary bypass

Hypotension refractory to maximal doses of alpha-adrenergic drugs after cardiac operations employing cardiopulmonary bypass (CPB) has been referred as "vasoplegic syndrome." Vasopressin has been used for its therapy with encouraging results.

16 patients (mean age 71, range 47 to 84 years) were treated with intravenous vasopressin (0.1-1 IU/min) for hypotension refractory to maximal doses (>30 microg/kg/min) of norepinephrine after undergoing complex cardiac operations employing CPB. Preoperative ejection fraction was 40.5% (mean, range 20% to 60%), preoperative NYHA class was 3.5 (mean). Hemodynamic measurements were obtained one hour before and one hour after beginning vasopressin infusion; urine output was measured for the 4 hours before and the 4 hours after beginning the infusion. Duration of vasopressin treatment was 58.8 +/- 37.3 hours (mean +/- SD).

Systolic blood pressure increased from 89.6 +/- 7.9 to 119.6 +/- 10.5 mmHg (mean +/- SD) (p < 0.001); systemic vascular resistance increased from 688.0 +/- 261.7 to 1043.3 +/- 337.1 dyne/s/cm2 (mean +/- SD) (p < 0.001); cardiac index decreased from 2.69 +/- 0.8 to 2.2 +/- 0.5 L/min/m2 (mean +/- SD) (p < 0.008); urine output increased from 36.8 +/- 30.4 to 72.8 +/- 38.2 mL/h (mean +/- SD) (p < 0.001). Seven patients (44%) survived the hospital stay.

High-dose vasopressin is effective in the treatment of the vasoplegic syndrome after cardiac operations employing cardiopulmonary bypass.