Hypothalamic-pituitary-adrenal axis dysfunction in hospitalized neonatal foals.
Authors: Hart K A, Slovis N M, Barton M H
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary: HPA Axis Dysfunction in Critically Ill Neonatal Foals Hart, Slovis and Barton's 2009 investigation into hypothalamic-pituitary-adrenal (HPA) axis function in hospitalised neonatal foals addresses a significant gap in equine critical care, drawing parallels from human medicine where transient HPA axis dysfunction is well-established as a predictor of poor outcomes in severely ill patients. The researchers measured basal ACTH and cortisol concentrations in 72 hospitalised foals at admission, alongside paired low-dose (10 µg) and high-dose (100 µg) cosyntropin stimulation tests, with reference values derived from 23 healthy age-matched controls. Remarkably, 46% of hospitalised foals demonstrated inappropriately low basal cortisol concentrations, whilst 52% showed inadequate cortisol response (delta cortisol) to the high-dose cosyntropin challenge—findings that were significantly associated with shock, multiple organ dysfunction syndrome, and reduced survival rates in septic foals. For equine practitioners, these results suggest that HPA axis assessment may represent a valuable prognostic tool in neonatal critical care, with an inadequate adrenal response to stimulation indicating more severe systemic compromise and poorer clinical trajectory. This work highlights the importance of endocrine evaluation in hospitalised foals and raises questions about potential therapeutic intervention strategies in this high-risk population.
Read the full abstract on PubMed
Practical Takeaways
- •Screen critically ill neonatal foals for HPA axis dysfunction using basal cortisol and cosyntropin stimulation testing, as this dysfunction correlates with poor prognosis and guides treatment decisions
- •Foals presenting with shock or multiple organ dysfunction syndrome should be evaluated for HPA axis dysfunction to identify those at highest risk of mortality
- •Consider HPA axis assessment as part of routine critical care evaluation in hospitalized neonates, as dysfunction is present in approximately half of cases and impacts survival
Key Findings
- •46% of hospitalized foals had inappropriately low basal cortisol concentration and 52% had inadequate cortisol response to high-dose cosyntropin stimulation
- •Inadequate delta cortisol response to 100 microg cosyntropin was significantly correlated with shock and multiple organ dysfunction syndrome
- •Foals with HPA axis dysfunction had decreased survival rates, particularly in septic foals
- •HPA axis dysfunction occurs frequently in hospitalized neonatal foals and negatively impacts disease severity and survival