The impact of caudally administrated tramadol on immune response and analgesic efficacy for pediatric patients: a comparative randomized clinical trial

Immune responses appear to be affected by anesthetics and analgesics. We investigated the effects of caudal tramadol on the postoperative immune response and pain management in pediatric patients. Sixty ASA-I pediatric patients aged 3-10 years undergoing lower abdominal surgery. Patients were randomly assigned either to a caudal bupivacaine (0.25%) group (group B), or a group that received caudal tramadol (1 mg/kg) added to the bupivacaine (0.25%) (group T). Both were diluted in a 0.9% NaCl solution to a total volume of 1ml/kg. The systemic immune response was measured by collecting blood samples preoperatively, at the end of anesthesia, and at 24 and 72 hours postoperatively, and studied for interleukin IL-6, C-reactive proteins (CRP) cortisol levels, and leucocytes with its differential count. Postoperative pain was assessed along with sedation scales. Postoperative production of IL-6 was significantly higher in group B at the end of anesthesia, than at the 24 hour, and at the 72 hour in group B and group T, respectively. The immune response showed leukocytosis with increased percentages of neutrophil and monocytes, and a decreased lymphocyte response rate within both groups with no significant differences between the groups. Cortisol and CRP were significantly higher in group B. Adding tramadol to a caudal bupivacaine block can attenuate the pro-inflammatory cytokine response, Cortisol, and CRP in children undergoing lower abdominal surgery.