Adrenocortical function and chronic lung disease of pre-maturity: an unresolved problem?

Prospective evaluation of postnatal steroid administration: a 1-year experience from the California Perinatal Quality Care Collaborative

OBJECTIVE

Postnatal steroids (PNSs) are used frequently to prevent or treat chronic lung disease (CLD) in the very low birth weight (VLBW) infant, and their use continues despite concerns regarding an increased incidence of longer-term neurodevelopmental abnormalities in such infants. More recently, there has been a suggestion that corticosteroids may be a useful alternative therapy for hypotension in VLBW infants, but there have been no prospective reports of such use for a current cohort of VLBW infants.

METHODS

The California Perinatal Quality Care Collaborative (CPQCC) requested members to supplement their routine Vermont Oxford Network data collection with additional information on any VLBW infant treated during their hospital course with PNS, for any indication. The indication, actual agent used, total initial daily dose, age at treatment, type of respiratory support, mean airway pressure, fraction of inspired oxygen, and duration of first dosing were recorded.

RESULTS

From April 2002 to March 2003 in California, 22 of the 62 CPQCC hospitals reported supplemental data, if applicable, from a cohort of 1401 VLBW infants (expanded data group [EDG]), representing 33.2% of the VLBW infants registered with the CPQCC during the 12-month period. PNSs for CLD were administered to 8.2% of all VLBW infants in 2003, 8.6% of infants in the 42 hospitals that did not submit supplemental data (routine data-set group, compared with 7.6% in EDG hospitals). Of the 1401 VLBW infants in the EDG, 19.3% received PNSs; 3.6% received PNSs for only CLD, 11.8% for only non-CLD indications, and 4.0% for both indications. At all birth weight categories, non-CLD use was significantly greater than CLD use. The most common non-CLD indication was hypotension, followed by extubation stridor, for which 36 (16.3%) infants were treated. For hypotension, medications used were hydrocortisone followed by dexamethasone. Infants treated with PNSs exclusively for hypotension had a significantly higher incidence of intraventricular hemorrhage, periventricular leukomalacia, and death when compared with infants treated only for CLD or those who did not receive PNSs.

CONCLUSIONS

The common early use of hydrocortisone for hypotension and the high morbidity and mortality in children receiving such treatment has not been recognized previously and prospective trials evaluating the short- and long-term risk/benefit of such treatment are urgently required.

Early pituitary-adrenal response and respiratory outcomes in preterm infants

OBJECTIVE

To assess the influence of circulating (basal) and stimulated plasma adrenocorticotrophin (ACTH) and serum cortisol on the duration of oxygen supplementation and development of chronic lung disease (CLD) in preterm, very low birthweight infants.

METHODS

A total of 226 human corticotrophin releasing hormone stimulation tests were performed on 137 very low birthweight infants on days 7 and 14 in a tertiary neonatal centre.

RESULTS

Multivariate regression analysis showed that the duration of oxygen supplementation was negatively associated with birth weight, but positively associated with alveolar-arterial oxygen gradient (A-aDO(2)) on the first day and with basal serum cortisol on day 14. In addition, the multivariate classification and regression trees model indicated that the two most useful indices for predicting CLD were clinical risk index for babies (CRIB) score (> 9) and peak serum cortisol (> 740 nmol/l) on day 14. The sensitivity, specificity, positive and negative predictive values of these factors for predicting CLD were 53%, 80%, 81%, and 70% respectively.

CONCLUSIONS

The findings suggest that birth weight, severity of initial respiratory failure as reflected by the A-aDO(2) gradient, and continuing "stress" with persistent increase in serum cortisol on day 14 are significant risk factors associated with the duration of oxygen supplementation, whereas early pituitary-adrenal response (basal and peak plasma ACTH and serum cortisol on day 7) is not an independent risk factor. Although CRIB score in combination with peak serum cortisol on day 14 are useful predictors of CLD, the need to use a stimulation test and the relatively late timing of the forecast render these indices unattractive for routine clinical use.