Infiltration of local anesthetics near the surgical wound has shown to improve early postoperative pain in various surgical procedures, especially after open heart surgery. Inadequate pain control reduces the capacity to cough, mobility, increases the frequency of atelectasis, and prolongs recovery.
Patients and methods
This study is designed to examine the efficacy of postoperative 1 g paracetamol/6 h, ketorolac tromethamine 30 mg/8–12 h as conventional analgesia versus bupivacaine plus magnesium sulfate through a single presternal catheter for postoperative pain relief after cardiac surgery. Forty patients were scheduled for valve replacement cardiac surgeries and were randomly assigned into two groups (20 patients in each group). Group M: each patient has received bupivacaine 0.125% with 5% magnesium sulfate through the presternal soft catheter at a fixed rate of 5 ml/h. Group B: each patient only has received postoperative 1 g paracetamol/6 h, ketorolac tromethamine 30 mg/8 h. For postoperative breakthrough pain, rescue analgesia in the form of 25 μg fentanyl was used, with recording of total required doses in both groups.
Results
The mean numeric pain scale was significantly lower in group M than in group B at most time points. The overall fentanyl requirements over the first 48 h were significantly lower in group M than in group B (33 ± 11.7 vs. 150 ± 1.6 μg, respectively). There was no statistically significant difference between the two groups regarding ICU stay and blood glucose level.
Conclusion
Local presternal bupivacaine with magnesium sulfate provided adequate postoperative analgesia and less opioid requirements.