Intrathecal Versus IV Fentanyl in Pediatric Cardiac Anesthesia

Systemic large-dose opioids are widely used in pediatric cardiac anesthesia, but there are no randomized, prospective studies regarding the use of intrathecal (IT) opioids for these procedures. In this randomized, prospective study, we compared cardiovascular and neurohumoral responses during IT or IV fentanyl anesthesia for pediatric cardiac surgery. Thirty children aged 6 mo to 6 yr were anesthetized with an IV fentanyl bolus of 10 &mgr;g/kg. This was followed by a fentanyl infusion of 10 &mgr;g · kg−1 · h−1 (Group IV;n = 10), 2 &mgr;g/kg of IT fentanyl (Group IT;n = 10), or combined IV and IT protocols (Group IV + IT;n = 10). Heart rate, mean arterial blood pressure, additional fentanyl doses, time to first analgesic requirement, COMFORT and Children’s Hospital of Eastern Ontario Pain Scale scores, and extubation time were recorded. Blood cortisol, insulin, glucose, and lactate levels were measured presurgery, poststernotomy, during the rewarming phase of cardiopulmonary bypass (CPB), and 6 and 24 h after surgery. The patients’ urinary cortisol excretion rates were also measured during the first postoperative day. The findings in all three groups were statistically similar, except for higher blood glucose levels during CPB in Group IT compared with Group IV (P < 0.004). Group IV + IT was the only group in which the increases in heart rate and mean arterial blood pressure from presurgery to poststernotomy were not significant. The 24-h urinary cortisol excretion rates (&mgr;g · kg−1 · d−1) were 61.51 ± 39, 92.54 ± 67.55, and 40.15 ± 29.69 for Groups IV, IT, and IV + IT, respectively (P > 0.05). A single IT injection of fentanyl 2 &mgr;g/kg offers no advantage over systemic fentanyl (10 &mgr;g/kg bolus and 10 &mgr;g · kg−1 · h−1) with regard to hemodynamic stability or suppression of stress response. The combination of these two regimens may provide better hemodynamic stability during the pre-CPB period and may be associated with a decreased 24-h urinary cortisol excretion rate.