Better Postsurgery Pain Control with Continuously Infused Regional Anesthetic

Phil Vinall

doi:10.1177/155989771441003

Summary

This article reviews a prospective randomized study [NCT02280291] that assessed whether a continuous infusion of regional anesthetic will reduce rebound pain and the need for narcotic analgesia after ankle fracture surgery.

Foot & Ankle Conditions
Orthopaedic Pain Management
Orthopaedics Clinical Trials
Pain Management
Acute & ChronicConduction Anesthesia

Foot & Ankle Conditions
Orthopaedic Pain Management
Orthopaedics Clinical Trials
Pain Management
Acute & Chronic
Orthopaedics
Conduction Anesthesia

Data presented by David Y. Ding, MD, New York University Hospital for Joint Diseases, New York, New York, USA, indicated that patients undergoing ankle fracture surgery who receive continuously infused regional anesthetic experience significantly reduced rebound pain and use less oral opioid analgesia over a 72-hour period when compared with those who receive single-shot regional anesthetic.

Peripheral nerve blocks generally provide good pain control intraoperatively that continues into the postoperative period. As these blocks wear off, however, patients often experience rebound pain 12 to 24 hours postoperatively that is subjectively worse than in patients treated without regional blocks.

This prospective randomized study [NCT02280291] was designed to assess whether a continuous infusion of regional anesthetic will reduce rebound pain and the need for narcotic analgesia after ankle fracture surgery. The surgeon, patient, and anesthesiologist were blinded until the day of surgery. Adults with an operative unilateral ankle fracture were eligible to participate. Patients with a bilateral fracture or neurologic condition that could interfere with pain sensation were excluded, as were those with an opioid addiction.

The use of pain medication (fentanyl and oxycodone/ acetaminophen) and visual analog scale (1 to 10) pain levels were tracked in the postanesthesia care unit. At discharge, patients were given a prescription for 5 tablets of oxycodone/acetaminophen (325 mg) for postoperative pain control. Pain scores, the number of pain medications taken, side effects (eg, nausea, vomiting), and adverse events (eg, infection, hematoma, allergy) were assessed at 8, 12, 24, 48, and 72 hours postoperatively.

Patients undergoing operative fixation of ankle fractures were randomized to receive either a popliteal sciatic nerve block as a single injection (SNB; n = 22) or a continuous infusion via an On-Q pump (n = 23). With the exception of age, which was significantly higher in the On-Q group (50.26 vs 38.86 years; P = .033), the groups were well balanced.

Patients in the SNB group experienced significantly more rebound pain during the 12- to 24-hour postoperative period (P = .002). Patients in the On-Q group had better maintenance of pain control throughout the first 3 days (Figure 1).

Figure 1.

Postoperative Pain: On-Q vs Sciatic Nerve Block as a Single Injection

SNB, sciatic nerve block as a single injection; VAS, visual analog scale.*P = .002.Reproduced with permission from NC Tejwani, MD.

Figure 2.

Mean Total Pain Pills: Discharge to 72 Hours Postoperatively

SNB, sciatic nerve block as a single injection.*P = .036.Reproduced with permission from NC Tejwani, MD.

Over the first 3 days, on average, patients in the On-Q group took 7 fewer oxycodone/acetaminophen pills than those in the SNB group (Figure 2) and had lower pain scores, even after 6 weeks (Figure 3). Eight patients in the On-Q group discontinued treatment early (most at the 24-hour mark); all discontinuations were accidental or the result of either equipment malfunction or mis-communication on the part of the patient. There were no differences in side effects from narcotics or in infections or neurologic symptoms.

Figure 3.

Visual Analog Scale Pain Levels at 2, 6, and 12 Weeks

SNB, sciatic nerve block as a single injection; VAS, visual analog scale.*P = .014. **P = .004.Reproduced with permission from NC Tejwani, MD.

Continuous infusion of peripheral nerve anesthesia postoperatively is a safe and effective way to minimize rebound pain, reduce oral pain medications, and improve pain scores.

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