Assessment of stress response attenuation with caudal morphine using a surrogate marker during pediatric cardiac surgery

Background: Measurement of biomarkers representing sympathetic tone and the surgical stress response are helpful for objective comparison of anesthetic protocols. Aims: The primary aim was to compare changes in chromogranin A levels following pump pediatric cardiac surgery between children who received bolus caudal morphine and those who received a conventional intravenous narcotic-based anesthesia regime. The secondary objectives were to compare hemodynamic responses to skin incision and the magnitude of the rise in blood sugar values between the groups. Settings and Design: A prospective observational study at a tertiary cardiac center. Measurements and Methods: Sixty pediatric cardiac surgical patients were randomized to Group I [n = 30] to receive intravenous narcotic-based anesthesia and Group II [n = 30] to receive single-shot caudal morphine. Baseline and postoperative chromogranin A levels, the hemodynamic response to skin incision, changes in blood sugar levels, and the total intravenous narcotic dose administered were recorded for each participant. Statistical Analysis: Pearson's Chi-squared test was used for comparison of categorized variables, and Mann–Whitney test was used for the analysis of continuous data. Results: Changes in chromogranin A levels and blood sugar levels were comparable in both groups. Group II received a lower narcotic dosage (P ≤ 0.001), and the response to skin incision as reflected by systolic pressure rise was less (P = 0.006). Conclusions: Surgical stress response attenuation was similar to caudal morphine as compared with intravenous narcotic-based anesthesia techniques as reflected by a similar increase in chromogranin A levels.