Orthopedics

Single-dose epidural injections of ropivacaine decreased postoperative pain scores when administered preoperatively in patients undergoing lumbar spine fusion, according to a presentation at the 2011 Annual Meeting of the North American Spine Society in Chicago.

“Our pre-emptive procedure could be used as [an] evidence-based and spine surgery-specific analgesic protocol for multimodal treatments in lumbar fusion surgery,” study investigator Kwang-Sup Song, MD, PhD, of Seoul, South Korea, said during his presentation.

Postoperative pain scores

In a prospective, randomized study, Song and colleagues injected 10 mL ropivacaine approximately 20 minutes before surgery into 30 patients who underwent lumbar spine fusion during a 2-year period. Excluded from the study were patients weighing less than 45 kg or more than 100 kg, those with an allergy to local anesthetics, severe underlying hepatic, renal or respiratory diseases and patients with a history of psychiatric or opioid medication.

The goal of the study was to measure how the analgesic affected postoperative pain against a control group with similar preoperative demographic characteristics who did not receive the medication.

“Single-dose epidural injection before lumbar surgery is simple and ideal in a prone position,” and there are no complications when using a catheter, Song explained. He and colleagues also reported that they witnessed no adverse effects of using ropivacaine in their study, such as motor weakness.

“The highest pain scores were experienced at postoperative 2 hours, [and] gradually diminished in both groups” until 12 hours postoperatively, according to Song. Investigators found significantly higher pain scores in the control group vs. the ropivacaine group.

Self-administered fentanyl

Patients in the study were permitted to self-administer fentanyl in computer-controlled doses postoperatively and investigators injected 50 µg/mL rescue doses of fentanyl whenever Visual Analog Scale scores were greater than 4 points. The frequency that patients used the fentanyl system to relieve pain “was higher in the control group at every time until postoperative 48 hours,” except between 8 hours and 12 hours postoperatively and fentanyl consumption was also higher in the control group until postoperative 12 hours, Song said.

Nausea and vomiting occurred less frequently in the ropivacaine group, but he noted that this difference was not statistically significant.

When measuring C-reactive proteins (CRP), investigators found higher CRPs in control patients at 72 postoperative hours. They noted that the anti-inflammatory properties of ropivacaine may have contributed to this phenomenon and further study is needed to investigate why CRP levels were affected. – by Jeff Craven

Reference:

• Song KS, Yang JJ. Early postoperative analgesic effects of single epidural ropivacaine injection before surgery in posterior lumbar spinal fusion: A randomized clinical trial. Paper #80. Presented at the 2011 Annual Meeting of the North American Spine Society. Nov. 2-5. Chicago.
• Kwang-Sup Song, MD, PhD, can be reached at the Department of Orthopedic Surgery, Chung-Ang University College of Medicine, 84 Heukseok-Ro, Dongjak-Gu, Seoul, Korea; +82 28 20 63 96; email: ksong70@cau.ac.kr.
• Disclosure: Song has no relevant financial disclosures.

This is an interesting study investigating the efficacy and safety of single-dose epidural local anesthetic prior to lumbar spine fusion. While the short-term results seem quite good based on the abstract, certainly further study is necessary to evaluate the efficacy and any potential downside effects at 36 hours, 48 hours and longer postoperatively (such as rebound pain and or other negative effects short- or longer-term, as well as urinary retention and narcotic requirements among others). With a push to shorten length of stays and perform more procedures as outpatients and 23-hour stays, these kind anestetic adjuncts become more exciting and intriguing.

— Todd J. Albert, MD
Orthopedics Today Editorial Board member
Chairman of the Department of Orthopaedics
President, The Rothman Institute
Philadelphia
Disclosure: Albert has no relevant financial disclosures.