Dexamethasone dosing, mechanical ventilation and the risk of cerebral palsy.

OBJECTIVE

Risk factors for cerebral palsy (CP) in premature infants include duration of mechanical ventilation and exposure to postnatal dexamethasone (DEX). Since DEX can reduce the duration of mechanical ventilation, limited DEX exposure could be beneficial.

METHODS

This was a retrospective, cohort study of infants of less than 1500 g birth weight surviving to discharge between 1 January 1996 and 30 June 2001 who received postnatal dexamethasone. DEX administration was based only on the need for O2 and/or mechanical ventilation. CP was diagnosed at over 10 months post-conceptional age. Univariate and multivariate analyses were used to determine significant risk factors and the relative contribution of these factors to overall risk of CP.

RESULTS

Of 218 eligible infants 162 were followed-up (74%). The CP rate was 27.3%. Significant risk factors for CP included gestational age, ventilator duration, DEX dose, presence of periventricular leukomalacia (PVL), seizures, diagnosis of retinopathy of prematurity (ROP) and use of vasopressors. By multiple logistic regression, ventilator duration, PVL, grade III/IV intraventricular hemorrhage (IVH) and DEX dose were significantly related to CP. By stepwise multiple regression, grade III/IV IVH and ventilator duration were the strongest risk factors, but DEX dose continued to be a significant risk factor.

CONCLUSIONS

The risk of CP was significantly related to the total cumulative dose of DEX. This could be due to a smaller exposure to DEX or to a reduced need for mechanical ventilation.