Effect of dexmedetomidine on pulmonary artery pressure after congenital cardiac surgery: A pilot study.

OBJECTIVE

To characterize the effects of dexmedetomidine on the pulmonary artery pressure in patients after congenital cardiac surgery.

DESIGN

Prospective observational pilot study.

SETTING

Pediatric cardiac intensive care unit at a university hospital.

PATIENTS

Twenty-two patients who received dexmedetomidine after cardiothoracic surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An echocardiogram was performed at three time points: 1) baseline (T0); 2) 6 mins after dexmedetomidine loading (T1); and 3) 1 hr after initiation of dexmedetomidine infusion (T2). Transthoracic echocardiography was used to estimate pulmonary artery pressure based on tricuspid regurgitant velocity (4 x Velocity2) plus central venous pressure. Twenty-two patients aged 0.9 yrs old (interquartile range, 7.9) were enrolled at a median of 1 hr (1.5) after surgery. Dexmedetomidine loading, 0.62 microg/kg (0.5), was given in all patients followed by 0.5 microg/kg/hr (0.6) at T1 and 0.65 microg/kg/hr (0.5) at T2. None of the patients had any increase in pulmonary artery pressure. Overall, the pulmonary artery pressure decreased from 30 mm Hg (13) at T0 to 24 mm Hg (10) at T1 and 26 mm Hg (8) at T2 (p < .001). The pulmonary artery pressure/systemic systolic blood pressure ratio decreased from 33% (12) at T0 to 23% (15) at T1 and 25% (13) at T2 (p = .002). There was no difference in the left ventricular function, Fio2, oxygen %, Po2, CO2, and vasoactive agents.

CONCLUSIONS

Administration of dexmedetomidine after congenital cardiac surgery was not associated with any increase in pulmonary artery pressure.