Study: Cortisol Quantification Investigation: Prospective, Observational Study Comparing Free versus Total Serum Cortisol in PICU Patients (CQI)
Study Type: Observational
Study Period: April 2008 – April 2009
Although the therapeutic use of corticosteroids has long existed there still remains a lack of consensus regarding the target population for corticosteroid replacement therapy. This is due, in large part, to the time consuming method of free cortisol assessment called equilibrium dialysis isolation. Cortisol Quantification Investigation (CQI) was a prospective, observational cohort study that assessed baseline total and free serum cortisol concentrations in a convenience sample of critically ill children exhibiting a spectrum of illness severity. The goal was to determine whether plasma ultrafiltration can be used in place of equilibrium dialysis by comparing the measured free cortisol following each fractionation method. If successful, this would make rapid (within hours) free cortisol measurements feasible in future CPCCRN studies.
This study was conducted on 165 critically ill children across the spectrum of illness severity. Analyses determined that centrifugal ultrafiltration fractionated free cortisol was fast and results correlated highly with equilibrium dialysis fractionated free cortisol. This study ascertains that real-time free cortisol quantification is feasible to potentially help guide future research to enhance clinical decision making for cortisol replacement therapy in the pediatric intensive care unit.