Dexamethasone effect on heart rate variability in preterm infants on mechanical ventilation

Area of Science:

• Neonatal medicine
• Pediatric critical care
• Cardiology

Background:

• Dexamethasone is used in preterm infants with chronic lung disease to aid mechanical ventilation weaning.
• Heart rate characteristics (HRC), including heart rate variability (HRV), may be affected by glucocorticoids and indicate extubation readiness.
• A sepsis monitor provides continuous HRV and HRC index data, which are inversely correlated.

Purpose of the Study:

• To evaluate the effect of dexamethasone on HRV and the HRC index in preterm infants.
• To determine the relationship between these physiological changes and extubation success.

Main Methods:

• 109 preterm infants on mechanical ventilation receiving dexamethasone were studied.
• Hourly HRV and HRC index were compared pre- and post-dexamethasone initiation.
• Infants were grouped by ventilation status: continued mechanical ventilation, successful extubation, or reintubation within 3 days.

Main Results:

• Dexamethasone significantly increased HRV (16.2 to 27.6 ms) and decreased the HRC index (1.51 to 0.79) (p < 0.001).
• Infants extubated within 24 hours of dexamethasone initiation showed higher HRV compared to those remaining on ventilation.
• No significant difference in HRV or its change was observed between successfully extubated infants and those requiring reintubation.

Conclusions:

• Dexamethasone administration improves HRV and reduces the HRC index in preterm infants with chronic lung disease on mechanical ventilation.
• These findings suggest dexamethasone may positively influence physiological parameters related to extubation readiness.