Tag Archive | interscalene block

After Shoulder Arthroplasty, Interscalene Block Results in Rebound Pain

Bar Graph for O'Buzz.jpegAnecdotally, many patients experience extreme discomfort after shoulder surgery. The April 5, 2017 issue of JBJS features results from a randomized controlled trial comparing morphine consumption and pain during the 24 hours following shoulder arthroplasty among two groups. One group (n=78) received a preoperative interscalene brachial plexus blockade, while the other (n=78) received intraoperative infiltration of bupivacaine liposome suspension.

Mean total postoperative narcotic consumption during the 24 hours after surgery was not significantly different between the two groups, although intraoperative narcotic consumption was significantly lower in the blockade group. The mean VAS pain scores were significantly lower in the blockade group at 0 and 8 hours postoperatively, the same as in the infiltration group at 16 hours postoperatively, and significantly higher than those in the infiltration group at 24 hours postoperatively. That last finding in patients undergoing blockade represents the phenomenon known as “rebound pain.”

The authors, Namdari et al., conclude that the “optimal postoperative pain regimen for shoulder arthroplasty…require[s] further investigation.” But their analysis uncovered four demographic factors that were associated with higher pain scores at 24 hours after surgery, regardless of the analgesic technique used:

  • Younger age
  • History of depression
  • Higher Charlson Comorbidity Score
  • Higher preoperative VAS score

In his commentary on the study, Ranjan Gupta, MD notes that one downside of the block approach is “an inability to assess the patient’s neurologic function after the surgical procedure.” His own early clinical experience leads him to favor the admittedly “laborious” infiltration approach, partly because “both patients and orthopaedic nurses who take care of these patients in the immediate postoperative time period can readily appreciate the lack of rebound pain.”