Subarachnoid clonidine and trauma response in cardiac surgery with cardiopulmonary bypass

AbstractBackground and objectivesThe intense trauma response triggered by cardiopulmonary bypass can lead to increased morbidity and mortality. The present study evaluated whether clonidine, a drug of the class of α-2 agonists, administered by spinal route, without association with local anesthetics or opioids, reduces this response in cardiac surgery with cardiopulmonary bypass.MethodA total of 27 patients between 18 and 75 years old, divided by non-blinded fashion into a control group (15) and a clonidine group (12), were studied. All patients underwent identical technique of general anesthesia. Then, only the clonidine group received 1μgkg−1 clonidine by spinal route. Levels of blood glucose, lactate and cortisol were measured at three consecutive times: T1, at the time of installation of invasive arterial pressure; T2, 10min after the first dose for cardioplegia; and T3, at the time of skin suture; and troponin I values at T1 and T3. The variation of results between T2–T1, T3–T2, and T3–T1 was also evaluated.ResultsThere was a statistically significant difference only with respect to the variation in blood glucose in the clonidine group: T3–T2, p=0.027 and T3–T1, p=0.047.ConclusionsSpinal clonidine at a dose of 1μgkg−1 did not decrease blood measurements of troponin, cortisol, or lactate. Blood glucose suffered a more moderate variation during the procedure in the clonidine group. This fact, already reported in the literature, requires further investigation to be clarified