Adrenal Responsiveness During the Perioperative Period in Children Undergoing Congenital Cardiac Surgery

Overview

Our objective was to determine whether a standard 1mg/kg intraoperative dose of dexamethasone results in similar drug levels for all patients and to characterize the relationship between these drug levels and the innate stress response following infant Cardiopulmonary Bypass (CPB). The investigators hypothesized that postoperative dexamethasone levels are highly variable, and that the infant stress response is inversely related to the amount of dexamethasone measured in the blood. To test this theory the investigators simultaneously measured blood levels of dexamethasone and cortisol at critical time points during the perioperative period for infants undergoing CPB for CHD surgery.

We conducted a single center prospective trial of infants (≤ 365 days of age) who presented to a single institution for congenital cardiac surgery. Blood was collected from study participants at 7 time points; 1) post-anesthesia induction, 2) post-CPB/pre-MUF, 3) Intensive care unit (ICU) arrival, 4) post-op hour 4, 5) post-op hour 8, 6) post-op hour 12, and 7) post-op hour 24. At each of the 7 time points blood was analyzed for levels of the following; dexamethasone, cortisol, ACTH, Interleukin (IL) 10, IL 8, and IL 6. In addition, the innate stress response was evaluated with a cosyntropin stimulation test. Each patient received a 1 mcg/1.73 m2 intravenous dose of cosyntropin at; anesthesia induction, prior to dexamethasone (time 1), ICU arrival (time 3), and 24 hours after ICU arrival (time 7). Cortisol levels were measured before (time 1, 3, and 7) and 30 minutes after cosyntropin administration (time 1a, 3a, and 7a).