Adrenal insufficiency in early phase of pediatric acute lung injury/acute respiratory distress syndrome

Abstract

Introduction: Adequate adrenal function is essential to survive critical illness. Several recent articles have reported the significant effect of adrenal insufficiency (AI) in patients with sepsis. However, the prevalence of AI in pediatric acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is so far still scanty. Thus, we elected to study its prevalence and its clinical outcome.

Methods: This is a cross-sectional observational study. We enrolled eligible infants and children aged between 1 month and 15 years who were admitted to our tertiary pediatric intensive care unit from February 1, 2005, to December 31, 2005, with ALI or ARDS diagnosed by the American-European Consensus criteria. A short corticotropin stimulation test (250 microg) was done within 24 hours of enrollment, and all clinical data were also recorded. Cortisol levels were measured at baseline, 30 minutes, and 60 minutes posttest. Adrenal insufficiency was defined as a baseline cortisol level of less than 15.1 microg/dL or an increment of cortisol level of less than 9 microg/dL after the adrenocorticotropic hormone stimulation test.

Results: Of 507 patients admitted to the pediatric intensive care unit, there were 20 diagnosed with ALI/ARDS. Of 20 children, 16 met the inclusion criteria and had none of the exclusion criteria. Of 16, there were 9 (56%) with ARDS, and 7 (44%) of 12 had ALI. The prevalence of AI was observed in 37.5% (6/16), diagnosed by baseline level criteria in 25% (4/16) and by incremental criteria in 12.5% (2/16). The Baseline level of the adrenocorticotropic hormone was 7.8 +/- 5 (nmol/L). The median age in the AI group was 2 months. Of 6 children, 5 (83.3%) were in the ARDS group. Pediatric Risk of Mortality III score was significantly higher in the AI group compared with that in the non-AI (P < .05). Initial Pao(2)/fraction of inspired oxygen ratio tended to be lower in the AI group (123.2 +/- 62.2) compared with that in the non-AI group (183.8 +/- 79.1), although not statistically significant (P = .1). The mortality was also not statistically different between the AI (1/6, 16.7%) and the non-AI groups (1/10, 10%).

Conclusions: Our study demonstrated that the prevalence of AI was common in pediatric ALI/ARDS. These results would be an initial step to further study the impact of AI on clinical outcomes of these children in a larger scale.