Use of dexmedetomidine in children after cardiac and thoracic surgery*

Abstract

In this report, we describe our experience with the use of dexmedetomidine in spontaneously breathing as well as in mechanically ventilated patients, after congenital cardiac and thoracic surgery. Retrospective case series. University hospital, pediatric cardiac intensive care unit. Thirty-three spontaneously breathing and five mechanically ventilated patients who received dexmedetomidine after cardiothoracic surgery. None. Thirty-eight patients, age 8 +/- 1.1 yrs old and weight 29 +/- 3.8 kg, were included. Seven patients (18%) were <1 yr old. Dexmedetomidine was used as a primary sedative and analgesic agent, and when its effect was considered inadequate, despite incremental infusion doses, a rescue agent was administered. The initial dexmedetomidine infusion dose was 0.32 +/- 0.15 microg/kg/hr followed by an average infusion of 0.3 +/- 0.05 microg/kg/hr (range 0.1-0.75 microg/kg/hr). There was a trend toward higher dexmedetomidine infusion requirement in patients <1 yr old compared with older children, 0.4 +/- 0.13 vs. 0.29 +/- 0.17 microg/kg/hr (p = .06). Desired sedation and analgesia were achieved during 93% and 83% of the dexmedetomidine infusion, respectively. According to the intensive care unit sedation scale (score 0-3) and two pain scales (Numeric Visual Analog Scale and Face, Legs, Activity, Cry, and Consolability, score 0-10), the mean sedation score was 1.3 +/- 0.6 (mild sedation) and the mean pain score was 1.5 +/- 0.9 (mild pain). The most frequently rescue drugs administered were fentanyl, morphine, and midazolam. Overall, 49 rescue doses of sedatives/analgesics were given. Patients <1 yr old required more rescue boluses than older children, 22 boluses (3.19 +/- 0.8) vs. 27 boluses (0.8 +/- 0.2, p = .003). Throughout the dexmedetomidine infusion there was no significant change in the systolic and diastolic blood pressure trend. Six patients (15%) had documented hypotension. In three, hypotension resolved with decreasing the dexmedetomidine infusion dose whereas in the other three, hypotension resolved after discontinuing the infusion. Although there was a trend toward lower heart rates, this was not clinically significant. One patient had an episode of considerable bradycardia without hypotension, which resolved shortly after discontinuing the dexmedetomidine infusion. No significant changes in the arterial blood gases or respiratory rates were observed. There was no mortality, and the total intensive care unit length of stay was 19 +/- 2 hrs. Our data suggest that dexmedetomidine is a well-tolerated and effective agent for both spontaneously breathing and mechanically ventilated patients following congenital cardiac and thoracic surgery.