Adductor Canal Block With Continuous Infusion Versus Intermittent Boluses and Morphine Consumption: A Randomized,...

Area of Science:

• Anesthesiology
• Orthopedic Surgery
• Pain Management

Background:

• Adductor canal block (ACB) is utilized for analgesia in total knee arthroplasty.
• Optimizing local anesthetic volume is hypothesized to enhance ACB efficacy.
• The administration method (bolus vs. infusion) may impact analgesia and mobility.

Purpose of the Study:

• To compare the efficacy of repeated intermittent boluses versus continuous infusion of adductor canal block (ACB).
• To determine if repeated bolus ACB improves analgesia and preserves mobility post-total knee arthroplasty.
• To evaluate opioid consumption, pain levels, and quadriceps muscle strength.

Main Methods:

• A randomized, blinded, controlled study was conducted on patients undergoing total knee arthroplasty.
• Patients received 0.2% ropivacaine via adductor canal catheter, either as repeated intermittent boluses (21 mL/3 h) or continuous infusion (7 mL/h).
• Primary outcome: postoperative opioid consumption (POD 0-2); secondary outcomes: pain, ambulation, and quadriceps strength.

Main Results:

• No significant difference in total opioid consumption (POD 0-2) between the bolus (23 mg) and infusion (26 mg) groups (P = .29).
• No significant differences in pain scores during knee flexion or at rest were observed between groups.
• Improved quadriceps muscle sparing was noted in the bolus group on POD 2, but this did not translate to improved ambulation.

Conclusions:

• Switching adductor canal block administration from continuous infusion to repeated intermittent boluses did not reduce opioid consumption or pain.
• The mode of ACB administration did not significantly impact patient mobility or functional recovery.
• Current evidence does not support repeated intermittent boluses over continuous infusion for adductor canal blocks in total knee arthroplasty.