Vishal Gunnala1, Rong Guo, Carla Minutti, Ramon Durazo-Arvizu, Cynthia Laporte, Herbert Mathews, Stephanie Kliethermis, Rahul Bhatia. 1. 1Division of Pediatric Critical Care, Ann and Robert H. Lurie Children's Hospital, Northwestern University, Chicago, IL. 2Clinical Research Office, Stritch School of Medicine, Loyola University Chicago, Maywood, IL. 3Division of Pediatric Endocrinology, Department of Pediatrics, Stritch School of Medicine, Loyola University Medical Center, Maywood, IL. 4Department of Biostatistics and Epidemiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL. 5Department of Pediatrics, Stritch School of Medicine, Loyola University Medical Center, Maywood, IL. 6Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University of Chicago, Maywood, IL. 7Division of Pediatric Critical Care, Department of Pediatrics, Stritch School of Medicine, Loyola University Medical Center, Maywood, IL.
Abstract
OBJECTIVE: To compare serum total, serum free and salivary cortisol in critically ill children. DESIGN: Prospective observational cohort study. SETTING: Tertiary pediatric critical care unit at Ronald McDonald Children's Hospital at Loyola University Medical Center. PATIENTS: We enrolled 59 patients (4 weeks to 18 years of age) between January 2012 and May 2013. Thirty-four patients were included in the salivary to serum free cortisol correlational analysis. INTERVENTIONS: Blood and saliva samples were obtained simultaneously within 24 hours of admission between the hours of 6 AM and 12 PM. Salivary cortisol was tested by liquid chromatography/tandem mass spectrometry, serum free cortisol by liquid chromatography/tandem mass spectrometry followed by equilibrium dialysis, and serum total cortisol by liquid chromatography/tandem mass spectrometry. MEASUREMENTS AND MAIN RESULTS: Salivary and serum free cortisol values from 34 patients had a correlation coefficient (r) of 0.87 (95% CI, 0.75-0.93; p < 0.0001). The total serum and salivary cortisol values had a correlation coefficient (r) of 0.67 (95% CI, 0.42-0.81; p < 0.0001). The total serum and serum free cortisol values had a correlation coefficient (r) of 0.83 (95% CI, 0.69-0.91; p < 0.0001). CONCLUSIONS: Serum free and salivary cortisol values correlate in critically ill children. Salivary cortisol can be used as a surrogate for serum free cortisol in critically ill pediatric patients. Salivary cortisol is a cost-effective and less invasive measure of bioavailable cortisol and offers an alternate and accurate method for assessing critical illness-related corticosteroid insufficiency in children.
OBJECTIVE: To compare serum total, serum free and salivary cortisol in critically ill children. DESIGN: Prospective observational cohort study. SETTING: Tertiary pediatric critical care unit at Ronald McDonald Children's Hospital at Loyola University Medical Center. PATIENTS: We enrolled 59 patients (4 weeks to 18 years of age) between January 2012 and May 2013. Thirty-four patients were included in the salivary to serum free cortisol correlational analysis. INTERVENTIONS: Blood and saliva samples were obtained simultaneously within 24 hours of admission between the hours of 6 AM and 12 PM. Salivary cortisol was tested by liquid chromatography/tandem mass spectrometry, serum free cortisol by liquid chromatography/tandem mass spectrometry followed by equilibrium dialysis, and serum total cortisol by liquid chromatography/tandem mass spectrometry. MEASUREMENTS AND MAIN RESULTS: Salivary and serum free cortisol values from 34 patients had a correlation coefficient (r) of 0.87 (95% CI, 0.75-0.93; p < 0.0001). The total serum and salivary cortisol values had a correlation coefficient (r) of 0.67 (95% CI, 0.42-0.81; p < 0.0001). The total serum and serum free cortisol values had a correlation coefficient (r) of 0.83 (95% CI, 0.69-0.91; p < 0.0001). CONCLUSIONS: Serum free and salivary cortisol values correlate in critically ill children. Salivary cortisol can be used as a surrogate for serum free cortisol in critically ill pediatric patients. Salivary cortisol is a cost-effective and less invasive measure of bioavailable cortisol and offers an alternate and accurate method for assessing critical illness-related corticosteroid insufficiency in children.