Hemodynamic Effects of Arginine-Vasopressin After Pediatric Cardiac Surgery

Background: Arginine-vasopressin is widely used for treatment of vasodilatory and mixed shock after pediatric cardiac surgery. Although a favorable effect on blood pressure has been documented, data on organ perfusion and tissue oxygen balance remain limited. Methods: We prospectively evaluated an observational cohort of 49 children after reparative cardiac surgery. Median age was 8 months (interquartile range 5 to 59 months) and weight 11.0 kg (interquartile range 7.2 to 26.3 kg). Patients who received arginine-vasopressin (n=23) for hypotension were compared with patients of similar surgical complexity who did not (n=26), using regression analysis. Results: Vasopressin dose was independently associated with an increase in systolic blood pressure (p<0.01), an increase in cerebral oxygen extraction (p=0.04), and an increase in renal oxygen extraction (p<0.01). No statistical difference was observed between treated and non-treated patients in diastolic blood pressure, blood lactate, or urine output. Conclusions: Arginine-vasopressin therapy restores blood pressure in hypotensive children after cardiac surgery but may have unfavorable effects on tissue oxygenation.