Comparison of the effects of single injection and continuous infusion popliteal nerve block on pain and hemodynamics in diabetic foot surgery; prospective randomized clinical trial.

OBJECTIVES

In patients undergoing surgery due to diabetic foot complications from uncontrolled diabetes may lead to neuraxial or general anesthesia-related issues. Regional anesthesia techniques can be preferred to prevent these complications. This study aimed to compare the hemodynamic effects and outcomes in terms of pain of continuous infusion and single injection methods of popliteal nerve block in patients undergoing surgery due to diabetic foot.

MATERIALS AND METHODS

Sixty-three patients in ASA II-IV risk group scheduled for diabetic foot surgery were randomized into two groups for popliteal nerve block as the anesthesia method. Group 1 (n:32), 30 mL of local anesthetic was administered around the popliteal nerve under ultrasound guidance and nerve stimulator. Group 2 (n:31) had a catheter placed beyond the needle tip by 4-5 cm. An elastomeric pump was prepared for the infusion of 2 mL/h of 0.25 % bupivacaine through the catheter. Hemodynamic parameters before and after the block, onset, block duration times, postoperative pain scores, time to analgesic requirement, patient satisfaction, and discharge time were recorded.

RESULTS

Pain scores were higher in Group 1 after 12 h postoperatively and in Group 2 after 60 h postoperatively (p = 0.006, p < 0.01, respectively). The time to the first analgesic requirement was not statistically different between Group 1 (mean 804.64 ± 1020.8 min) and Group 2 (mean 2012.78 ± 1424 min) (p = 0.072). There was no significant difference in systolic, diastolic, mean arterial blood pressure, and heart rate between groups before and after successful blockade (p > 0.05).

CONCLUSIONS

Continuous infusion method of popliteal nerve block provides a longer pain-free period. Both methods showed similar hemodynamic data and low pain scores. Although continuous infusion method provides better analgesia, its procedural cost, technical difficulties, and adverse effects on patient comfort should also be considered.