Plasma Cortisol Levels in Infants With Respiratory Distress During Different Phases of Neonatal Transport: A Pilot Prospective Observational Before-After Study

Objective: The transport of sick newborn infants with respiratory distress leads to unwanted stress at time of physiological instability. There is dearth of studies to evaluate these stress levels. This pilot prospective observational before-after study aimed to evaluate the plasma cortisol levels (as surrogate marker of stress) in infants with respiratory distress during different phases of neonatal transport. Methods: Plasma cortisol was measured before transport, on arrival at tertiary hospital, and after 48 hours. Perinatal demographics and retrieval and disease characteristics were collected from neonatal transport and neonatal intensive care unit records. Neonatal transport factors that may affect the cortisol response were also evaluated. Results: A total of 55 infants were recruited, of which 40 infants who had cortisol levels measured in all the 3 phases of neonatal transport were included in the final analyses. Median (interquartile range) cortisol levels measured before transport, on arrival at tertiary hospital, and after 48 hours were 520 (250-770) nmol/L, 315 (172.5-520) nmol/L, and 125 (70-250) nmol/L. There was a reduction in the paired median cortisol levels between the sample taken before transport and arrival at a tertiary hospital by 24% (P = .048) and at 48 hours by 73% (P < .001). Gestational age, gender, duration of respiratory support, and transport duration did not alter the change in cortisol levels. Conclusion: Neonatal transport does not seem to influence the anticipated fall in plasma cortisol levels post-birth in infants with respiratory distress. Future studies with larger sample size using both behavioral and physiological parameters for stress evaluation in neonatal transport are warranted.