Peripheral Nerve Blockade safe, effective for management of Hip Fracture Pain: Study

Hip fractures typically occur in older adults (aged 65 years and older), who report considerable pain and have a one-year mortality rate of 12% - 25%. Peripheral nerve blocks, which are frequently used by anesthesiologists or pain specialists, involve administering local anesthetics around the sensory nerves that innervate the anterior capsule of the hip joint, the primary source of postoperative pain. The specific nerves involved are the femoral, obturator, and accessory obturator nerves.

Local anesthetics, such as bupivacaine (maximum dose: 2 mg/kg) and ropivacaine (maximum dose: 3 mg/kg), will successfully control pain for up to 6-8 hours. Adding 4 mg of perineural dexamethasone can prolong the duration of a block by 5.4 hours. The efficacy of a nerve block can be assessed in 15 to 20 minutes by monitoring for pain and sensory loss in the affected limb. Ultrasound-guided peripheral nerve blocks allow the utilization of peripheral nerve blocks to expand beyond anesthesiologists and into emergency medicine physicians and other credentialed providers. The American College of Emergency Physicians has approved ultrasound-guided nerve blocks as a core skill of multimodal pain management.

Evidence from Clinical Trials Towards Peripheral Nerve Blocks

In 2022, a systematic review conducted of 12 trials with a total sample of 976 patients, compared ultrasound-guided blocks (femoral nerve block and/or fascia iliaca compartment block) to traditional analgesia (opioids, NSAIDs, or placebo blocks). The results included:

• A clinically significant decrease in pain scores was found at 2 hours post-injection (mean difference: −2.26; VAS 0-10;95% CI, −2.97 to −1.55; p<0.001). Reduced preoperative intravenous morphine equivalent use occurred (−5.34 mg; 95% CI, −8.11 to −2.58; p=0.003). Lower risk of delirium was noted (RR: 0.6; 95%CI, 0.38-0.94; p=0.03). Reduced risk of serious adverse events such as respiratory depression and sedation were found (RR: 0.33; 95% CI, 0.15-0.73; p=0.006). Higher patient satisfaction scores (mean difference: 25.9; VAS 0-100; 95% CI, 19.74-32.07; p<0.001) were found, but evidence quality was assessed as low to very low, warranting caution in the interpretation of results.

• A 2020 Cochrane systematic review of 49 RCTs (3,061 patients) subsequently confirmed the benefits of peripheral nerve blocks: Reduced pain on movement at 30 minutes post-injection (SMD: −1.05; 95%CI, −1.25 to −0.86; equivalent to a reduction of 2.5 on a 0-10 scale; high certainty evidence); Lower risk of acute confusional state (RR: 0.67; 95%CI, 0.50-0.90; NNT = 12; high certainty evidence); and Reduced risk of chest infections (RR: 0.41; 95% CI, 0.19-0.89; NNT = 7; moderate certainty evidence).

Peripheral nerve blocks provide safe and effective options for hip fracture pain management that can be administered outside of the operating room by credentialed providers. Peripheral nerve blocks provide effective pain management while minimizing opioid use and associated side effects, and should be incorporated into clinical practice as part of the clinical pathway.

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