Is dexmedetomidine a potential neuroprotective agent for term neonates with hypoxic-ischemic encephalopathy?

Abstract

Introduction The negative impacts of standard pharmacologic sedative agents suggest that alternative agents should be investi- gated. Dexmedetomidine could be the new option for se- dation in newborns with hypoxic-ischemic encephalopa- thy requiring mechanical ventilation. The objective is to determine the impact of dexmedetomidine and other sed- atives on the cerebral blood flow and outcomes of hy- poxic-ischemic encephalopathy in term neonates. Material and methods Data of 205 term infants with hypoxic-ischemic enceph- alopathy Sarnat stage II-III was collected during ≤72 hours of life. All the infants were divided using a simple open randomization by pharmacological sedative agents for mechanical ventilation synchronizing into groups by dexmedetomidine (n=46) and the control group (n=159), which included morphine, sodium oxybutyrate, and diaz- epam in standard recommended doses. A comparative analysis of the effect of dexmedetomidine and other drugs on cerebral perfusion and outcomes of hypoxic-is- chemic encephalopathy was performed. Results A significant difference between groups in days of tra- chea extubation (p=0.022) was found; the chance for ba- bies to be extubated before 7 days of treatment was significantly higher in the dexmedetomidine group 68% versus 33% in the control group (p=0.018) with HR 0.48 (95% CI 0.27-0.86, p=0.011). Also, the NIRS index rScO2 differed significantly between the studied and con- trol groups on the 1st day of treatment (65% versus 79%, p=0.012) and on the 2nd day of treatment (74% versus 81%, p=0.035). Mean arterial pressure was higher in the dexmedetomidine group compared to the control group (58 [51-65] mm Hg versus 53 [46-60] mm Hg, p<0.001), with a lower dose of dobutamine (EV -1.87, 95% CI from -3.25 to -0.48, p=0.009). In the dexmedetomidine group, the rate of seizures was significantly lower on the 1st day of observation (4.3% versus 48.3%, p <0.001); the inci- dence of unfavorable outcome as cerebral leukomalacia was also 7 times lower in the dexmedetomidine group compared to the control group (2.2% versus 15.1%, p = 0.018). Conclusions Dexmedetomidine is a safe sedative agent with a stable hemodynamics profile, no adverse cerebral influence and possible neuroprotective effects in term infants with HIE, additional to standard therapeutic hypothermia.

Keywords

• hypoxia
• ischemia
• encephalopathy
• dexmedetomidine
• neonates