Programmed, intermittent boluses versus continuous infusion to the sciatic nerve - a non-inferiority randomized,...

Area of Science:

• Anesthesiology
• Pain Management
• Regional Anesthesia

Background:

• Previous studies found no analgesic differences between programmed, intermittent boluses (PIB) and continuous infusion for nerve blocks.
• Equal local anesthetic (LA) doses in prior trials may have obscured potential dose-sparing benefits of PIB.
• The time-action profile of individual boluses was not considered, potentially overlooking PIB's efficiency.

Purpose of the Study:

• To compare the analgesic efficacy of PIB, with bolus intervals matched to LA duration, against continuous infusion.
• To test the hypothesis that PIB offers non-inferior analgesia while consuming less LA.
• To evaluate the dose-sparing potential of PIB in catheter-based nerve blocks.

Main Methods:

• A non-inferiority randomized controlled trial involving 81 patients undergoing foot surgery.
• Catheter-based sciatic nerve blocks using ropivacaine 0.2%: PIB (10 ml every 8 hours) vs. continuous infusion (6 ml/hour).
• Rescue boluses (10 ml) were available every 4 hours; pain (VAS) was assessed for 72 hours via AUC calculation.

Main Results:

• PIB demonstrated non-inferior analgesia compared to continuous infusion (mean AUC-VAS 1621 vs. 1206 mm h).
• The difference in AUC-VAS was -416 mm h (95% CI -1076 to 244; p=0.217), confirming non-inferiority.
• Mean total LA consumption was significantly lower with PIB (136 ml) versus continuous infusion (468 ml; p < 0.0001).

Conclusions:

• Programmed, intermittent boluses (PIB) provide non-inferior analgesia for 72 hours post-surgery compared to continuous infusion.
• PIB significantly reduces local anesthetic consumption.
• PIB represents a more efficient approach to regional anesthesia for postoperative pain management.