R5 Continuous Infusion for Pain Control after Pediatric Cardiothoracic Surgery Associated with Longer Length of Stay

Abstract

Subjects were patients aged 3 months-4 years post-cardiac surgery with a midline sternotomy incision and planned early extubation at Advocate Children's Hospital-Oak Lawn. Sixty subjects were randomized to receive either a continuous infusion of morphine and midazolam or normal saline. The infusion group received a continuous intravenous morphine infusion at 0.03 mg/kg/hr along with a midazolam drip at 0.03 mg/kg/hr. Morphine bolus doses were available at 0.05 mg/kg/dose every two hours and midazolam 0.05 mg/kg/dose every one hour. Additional doses available at the discretion of the treating team. The control group received a normal saline infusion and the same bolus dosing. Providers were blinded to the infusion, but not to the bolus doses. Both groups received acetaminophen and ketorolac. FLACC scores were recorded hourly and as needed. There was no difference in number of bolus medication received between groups (p=0.39 for morphine, p=0.8 for midazolam). The mean FLACC score was 1.58 in the bolus group and 1.34 in the infusion group (p=0.35). Total morphine dose given was higher in the infusion group (0.23 mg/kg versus 0.9 mg/kg, p<0.01). Total midazolam dose given was higher in the infusion group (0.18 mg/kg versus 0.9 mg/kg, p<0.01). The length of ICU stay (LOS) was longer in the infusion group (4.5 days versus 2.7, p=0.03). The total hospital LOS was also longer in the infusion group (8.4 days versus 4.9, p=0.03). The addition of a continuous infusion did not decrease the amount of intermittent bolus doses or improve FLACC scores. Subjects in the infusion group did receive a significantly higher total dosage of these medications. We speculate that these higher doses led to longer ICU and hospital lengths of stay. Based on these findings, use of continuous infusions should be discouraged as routine practice after pediatric cardiac surgery in this age group.