What is the recommended pain management strategy using a Peng block for hemiarthropasty (half joint replacement)?

Pain Management Using PENG Block for Hemiarthroplasty

The PENG (pericapsular nerve group) block is a promising regional anesthesia technique for hemiarthroplasty that deserves further investigation, but currently lacks sufficient evidence to be recommended as a first-line pain management strategy. 1

Current Evidence for PENG Block in Hip Surgery

• PENG block targets sensory branches of the femoral, obturator, and accessory obturator nerves, which innervate the anterior capsule of the hip joint 1
• Most available literature has evaluated PENG block for hip fracture management rather than hip replacement surgery 1
• Recent studies show PENG block provides limited benefit to postoperative analgesia in the recovery room with no discernible benefits thereafter when added to intra-articular local anesthetic injections 2
• Meta-analysis data indicates PENG block decreases 24-hour oral morphine equivalent consumption by a mean difference of 3.75 mg, but this benefit may not surpass the minimal clinically important difference threshold 3

Recommended Regional Anesthesia Techniques for Hip Surgery

• Fascia iliaca block is currently the preferred nerve block when a regional technique is indicated for hip arthroplasty 1
• Fascia iliaca block has demonstrated lower pain scores, reduced morphine consumption, and shorter length of stay without increased risk of falls 1
• Local infiltration analgesia (LIA) is another recommended option that has shown benefits in pain control during the first 24 hours postoperatively 1

Techniques to Avoid

• Femoral nerve block is not recommended due to significant incidence of muscle weakness that can delay mobilization 1, 4
• Lumbar plexus block is not recommended due to being a deep block with potential risks 1
• Intrathecal morphine remains controversial due to side effects including nausea, vomiting, pruritus, and delayed ambulation that may interfere with early rehabilitation protocols 1

Comparative Effectiveness of PENG Block

• When compared to quadratus lumborum (QL) block, PENG block showed similar opioid consumption outcomes, but QL block demonstrated lower pain scores in the immediate post-anesthesia care unit period 5
• PENG block combined with lateral femoral cutaneous nerve block resulted in earlier first postoperative walking time (19.6 vs 26.5 hours) and greater hip flexion compared to supra-inguinal fascia iliaca compartment block 6
• PENG block has been successfully used in primary total hip arthroplasty as a solo block and may be used in combination with other regional blocks 7

Practical Approach to Pain Management for Hemiarthroplasty

• Start with multimodal analgesia including paracetamol, NSAIDs or COX-2 selective inhibitors as baseline therapy 1
• Consider fascia iliaca block as the preferred regional technique when a nerve block is indicated 1
• If motor-sparing benefits are particularly important for early mobilization, PENG block may be considered as an alternative, though evidence is still evolving 7, 6
• Local infiltration analgesia should be considered as another effective option for pain management 1
• Avoid techniques that cause significant motor blockade, which can delay mobilization and increase fall risk 1, 4

Monitoring and Safety Considerations

• Monitor for quadriceps weakness after any hip regional anesthesia technique, as this may impact early mobilization 4
• PENG block appears to have motor-sparing benefits compared to traditional approaches like femoral nerve block 7
• When using any regional technique, balance the potential benefit on postoperative pain against side effects such as delayed mobilization 1