Renin-Angiotensin-aldosterone system and hypothalamic-pituitary-adrenal axis in hospitalized newborn foals.
Authors: Dembek K A, Onasch K, Hurcombe S D A, MacGillivray K C, Slovis N M, Barr B S, Reed S M, Toribio R E
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary Sepsis and hypoperfusion in hospitalised newborn foals frequently trigger dysfunction of the hypothalamic-pituitary-adrenal axis, leading to relative adrenal insufficiency; however, how the renin-angiotensin-aldosterone system (RAAS) and mineralocorticoid response function alongside this condition remains poorly characterised in neonatal equine patients. Dembek and colleagues measured plasma concentrations of renin, angiotensin II, aldosterone, and cortisol in critically ill foals admitted to referral centres, stratifying animals by disease severity and illness outcomes to determine whether RAAS dysregulation occurs concurrently with adrenal insufficiency. The researchers documented significant alterations in both axes during sepsis and systemic inflammation, with aldosterone and cortisol responses varying markedly between surviving and non-surviving foals, and between those with and without sepsis-related multi-organ dysfunction. Recognition of these neuroendocrine dysfunctions carries important implications for clinical management: practitioners should consider that critically ill neonates may have blunted mineralocorticoid and glucocorticoid responses despite appropriate physiological stimulus, potentially necessitating more aggressive fluid management or targeted hormone replacement strategies in severe cases. Understanding the integrated failure of both regulatory systems in sick foals may refine prognostic assessment and guide therapeutic decision-making in neonatal intensive care settings.
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Practical Takeaways
- •Assess HPAA function and adrenal status in critically ill newborn foals as relative adrenal insufficiency may complicate sepsis management and organ perfusion
- •Monitor mineralocorticoid and renin-angiotensin responses in hospitalized neonates, as dysregulation of these systems may worsen hypoperfusion and systemic illness
- •Consider adrenal support as part of critical care protocols for septic foals when signs of relative adrenal insufficiency are present
Key Findings
- •HPAA dysfunction and relative adrenal insufficiency are common complications in septic foals during hospitalization
- •The renin-angiotensin-aldosterone system and mineralocorticoid response are dysregulated in newborn foals with relative adrenal insufficiency
- •Interactions between RAAS and HPAA during illness and hypoperfusion are critical for maintaining organ function in neonatal foals