ASRA Conference Coverage

Emergency Department Nerve Blocks Reduce Opioid Use, Analgesia Wanes Before Surgery

Anthony Calabro, MA

Key Highlights

  • Ultrasound-guided nerve blocks (UGNBs) administered in the emergency department (ED) led to significant opioid reduction.
  • Opioid requirements returned to baseline levels after 36 hours in most patients.
  • 10% of patients demonstrated block resolution prior to surgery.
  • An acute pain consult may help maintain analgesia through to surgical fixation.

Ultrasound-guided nerve blocks (UGNBs) for hip fractures administered in the ED led to a meaningful reduction in opioid requirements. However, for many patients, the analgesic benefit wore off within 36 hours—before they underwent surgical fixation. The study, which was presented at the 50th Annual Regional Anesthesiology and Acute Pain Medicine Meeting in Orlando, FL, found that approximately 10% of patients had evidence of block resolution prior to surgery.

Patients with hip fractures are often older and frail, putting them at increased risk for opioid-related adverse effects. Although there has been an expanded use of early regional anesthesia, including UGNBs, in improving short-term pain outcomes, little is known about the durability of these blocks leading up to surgery. Delays to the operating room due to hospital logistics and preoperative optimization may create a gap in analgesia that could impact patient comfort and safety.

In this retrospective analysis, researchers examined patients with hip fractures who received ED-administered nerve blocks at two academic hospitals in the northeastern United States over a 42-month period. The study aimed to assess the pain trajectories and opioid consumption patterns before, during, and after nerve block placement. No patient consent was required due to the observational study design.

The average opioid requirement before nerve block placement was 14.8 mg oral morphine equivalents (OME). During the block procedure, this fell to 9.7 mg OME, and in the first 12 hours post-block, opioid use decreased further to 7.11 mg OME. However, by 36 to 48 hours, opioid requirements rebounded to pre-block levels. Nineteen patients (10.5%) had opioid needs that exceeded their combined pre- and intra-block levels, indicating block resolution. Most patients underwent surgery within 36 hours of admission, but some did not, raising the question of whether a second block or catheter placement could be beneficial.

The study is limited by its retrospective design, inclusion of only two centers, and the potential for selection bias among patients who received nerve blocks. These factors may restrict generalizability and suggest a need for further prospective research.

“Further collaborative work with anesthesiology, acute pain, orthopedic surgery, and emergency medicine physicians on these subjects is imperative to optimize care for this vulnerable population,” the authors concluded.

Reference
Winters M, Horita H, Roberts JA IV, et al. Resolution of emergency department nerve blocks for hip fractures prior to surgery: a retrospective analysis. Poster presented at: 50th Annual Regional Anesthesiology and Acute Pain Medicine Meeting; May 2, 2025; Orlando, FL. https://asra.com/events-education/ra-acute-meeting