Use of low-dose dexmedetomidine in combination with opioids and midazolam in pediatric cardiac surgical patients: randomized controlled trial.

Background: Dexmedetomidine is a selective agonist of α2 receptors that induces hypnotic, sedative and mild analgesic effect. The aim of our study was to test the effects of dexmedetomidine in combination with opioids and benzodiazepines compared to benzodiazepine-opioids alone.

Methods: A randomized controlled trial was conducted. Patients (children >30 days and <24 months undergoing correction of complex congenital heart diseases [CHD]) were randomized to receive 0.5 mcg/kg/h dexmedetomidine in addition to half dose of opioids and benzodiazepines (D-CASES) or standard dose opioids and benzodiazepines (CONTROLs).

Primary Outcome: to compare the duration of mechanical ventilation (MV) in D-CASEs and CONTROLs.

Secondary Outcomes: 1) the degree of sedation; 2) the onset of withdrawal symptoms; 3) the occurrence bradycardia and hypotension.

Results: Overall, 48 patients, 26 in CONTROLs group and 22 in D-CASEs group were ultimately included in the analysis after enrollment. The median duration of MV was 33.5 (16.7-75) hours in CONTROLs and 41.5 (23.7-71.2) hours in D-CASEs (P=0.51). Dexmedetomidine did not affect COMFORT and FLACC scales but it reduced the SOS scale in 15 D-CASEs vs. 11 CONTROLs (P=0.001). The incidence of bradycardia and hypotension and vasoactive support did not show significant differences in the two groups.

Conclusions: Low dose of dexmedetomidine in combination with morphine and midazolam was safe in a high-risk cohort of CHD children after cardiac surgery and reduced the onset of withdrawal symptoms. However, it did not decrease MV time and the total amount of other sedative and analgesic drugs required in the post-operative period.