EVALUATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS IN A PAEDIATRIC INTENSIVE CARE UNIT

Area of Science:

• Pediatric Critical Care Medicine
• Endocrinology
• Hormone Physiology

Background:

• Relative adrenal insufficiency (RAI) is characterized by inadequate cortisol production from hypothalamic-pituitary-adrenal (HPA) axis dysfunction during severe illness.
• Evaluating HPA axis function and RAI is critical in tertiary pediatric intensive care units (PICUs).

Purpose of the Study:

• To assess the hypothalamic-pituitary-adrenal (HPA) axis function and the prevalence of relative adrenal insufficiency (RAI) in pediatric intensive care unit (PICU) patients.
• To correlate cortisol levels with disease severity and outcomes in critically ill children.

Main Methods:

• A prospective cohort study involving 100 PICU patients.
• Measurement of basal serum adrenocorticotropic hormone (ACTH) and cortisol levels, compared to a control group.
• Performance of a low-dose ACTH stimulation test for patients with basal cortisol < 18 µg/dL.

Main Results:

• PICU patients exhibited significantly higher basal cortisol levels than controls (P < 0.05).
• All stimulated patients (n=24) showed adequate cortisol response (delta > 9 µg/dL, peak > 18 µg/dL).
• Basal cortisol levels positively correlated with Pediatric Risk of Mortality (PRISM) III scores (P < 0.05; r = 0.363).

Conclusions:

• Elevated basal or stimulated cortisol levels in the acute stress phase signify disease severity in critically ill children.
• Patients with markedly high cortisol levels require vigilant monitoring due to a heightened risk of mortality.