Elevated Baseline Cortisol Levels Are Predictive of Bad Outcomes in Critically Ill Children

Area of Science:

• Pediatric critical care medicine
• Pediatric endocrinology
• Clinical pathology

Background:

• Adrenal insufficiency diagnosis in critically ill children remains challenging.
• Cortisol response to adrenocorticotropin (ACTH) stimulation is a key diagnostic tool.
• The prognostic value of baseline cortisol levels in pediatric critical illness needs further clarification.

Purpose of the Study:

• To evaluate baseline and ACTH-stimulated cortisol levels in critically ill children.
• To determine the association between cortisol levels and clinical outcomes, including mortality.
• To assess the utility of baseline cortisol in predicting severity of illness.

Main Methods:

• Retrospective study of 99 children in a pediatric intensive care unit (PICU) undergoing ACTH testing (2006-2013).
• Collected data included demographics, diagnoses, vasoactive-inotropic scores, PICU length of stay, and mortality.
• Measured baseline and post-ACTH plasma cortisol, lactate, and hematologic/chemistry panels.

Main Results:

• A baseline cortisol level ≥ 600 nmol/L was associated with a 36% mortality rate versus 18% for levels < 600 nmol/L (OR 2.6, P=0.05).
• Positive correlations were found between baseline cortisol and lactate levels (r=0.40, P<0.0001), vasoactive-inotropic scores (r=0.24, P=0.02), and mortality (P=0.05).
• No significant correlation was observed between peak cortisol or cortisol increment post-ACTH stimulation and mortality.

Conclusions:

• Elevated baseline cortisol levels in critically ill children correlate with increased illness severity, higher lactate, and greater mortality risk.
• Routine measurement of baseline cortisol is recommended for identifying critically ill children at high risk of mortality.
• ACTH stimulation test results did not correlate with mortality in this cohort.