Controversies surrounding critical illness‐related corticosteroid insufficiency in animals

OBJECTIVES: To describe the controversies surrounding critical illness-related corticosteroid insufficiency (CIRCI) and the use of hydrocortisone in critically ill patients, and to present published diagnostic and therapeutic strategies in companion veterinary species. ETIOLOGY: Critical illness-related corticosteroid insufficiency may be due to hypothalamic-pituitary-adrenal (HPA) axis dysfunction, alterations in cortisol-plasma protein binding, target cell enzymatic changes, changes in glucocorticoid receptor (GR) function, or a combination of these or other factors present during critical illness. DIAGNOSIS: Appropriate tests to diagnose CIRCI are unknown. The diagnosis in people is currently based on response to treatment with hydrocortisone. There is currently no consensus on appropriate diagnostic feature(s) in veterinary species. THERAPY: Low-dose hydrocortisone is the treatment of choice for patients with CIRCI. PROGNOSIS: If the patient survives the critical illness, prognosis for resolution of CIRCI and hydrocortisone dependence is very good.