Serum cortisol levels predict survival in critically ill dogs

Abstract

OBJECTIVE: To investigate whether serum cortisol (SC) concentration is a useful prognostic indicator for survival versus nonsurvival to hospital discharge in critically ill dogs. ANIMALS: 229 client-owned dogs. PROCEDURES: Medical records were retrospectively reviewed to identify critically ill dogs that were hospitalized between January 2010 and May 2018 and that had SC concentrations measured ≤ 3 days after admission. Results for SC concentrations were compared for dogs grouped by survival versus nonsurvival to hospital discharge, with versus without sepsis, and other variables of interest. The predictive value of SC concentration for nonsurvival to hospital discharge was assessed (OR, sensitivity, and specificity) for cutoffs determined from a ROC curve or reference limit. RESULTS: Median SC concentration was higher in dogs that did not survive to hospital discharge (8.5 μg/dL; interquartile [25th to 75th percentile] range, 4.8 to 11.8 μg/dL), compared with concentration in those that were discharged alive (4.5 μg/dL; interquartile range, 2.5 to 6.9 μg/dL). The area under the ROC curve was 0.72 (95% confidence interval [CI], 0.64 to 0.81) for SC concentration predicting nonsurvival. The calculated optimum cutoff of SC concentration was 7.6 μg/dL, at which the OR, sensitivity, and specificity for nonsurvival were 5.4 (95% CI, 2.7 to 10.9), 58%, and 80%, respectively. Alternatively, when the upper reference limit for SC concentration (5.8 μg/dL) was used as the cutoff, the OR, sensitivity, and specificity for nonsurvival were 3.6 (95% CI, 1.8 to 7.1), 67%, and 64%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that SC concentration could be used as part of an overall assessment of prognosis in critically ill dogs.