ABSTRACT
BACKGROUND AND HYPOTHESIS: Arthroscopic rotator cuff repair can be a painful outpatient procedure. The purpose of this study was to evaluate the efficacy of continuous subacromial bupivacaine infusion to relieve pain after arthroscopic rotator cuff repair. We hypothesized that patients receiving continuous subacromial bupivacaine infusions after arthroscopic rotator cuff repair will have less postoperative pain in the early postoperative period than placebo and control groups. MATERIALS AND METHODS: Eighty-eight patients undergoing arthroscopic rotator cuff repair were randomized in a blinded fashion into 1 of 3 groups. Group 1 received no postoperative subacromial infusion catheter. Group 2 received a postoperative subacromial infusion catheter filled with saline solution. Group 3 received a postoperative subacromial infusion catheter filled with 0.5% bupivacaine without epinephrine. Infusion catheters were scheduled to infuse at 4 mL/h for 50 hours. Postoperative pain levels were assessed with visual analog scale scores hourly for the first 6 postoperative hours, every 6 hours for the next 2 days, and then every 12 hours for the next 3 days. Patients recorded daily oxycodone consumption for the first 5 postoperative days. RESULTS: Immediately postoperative, the group with no catheter had significantly lower visual analog scale scores (P = .04). There were no significant differences in visual analog scale scores among the groups at any other time point. There were no differences found among the groups regarding mean daily oxycodone consumption. CONCLUSION: The use of continuous bupivacaine subacromial infusion catheters resulted in no detectable pain reduction after arthroscopic rotator cuff repair based on visual analog scale scores and narcotic medication consumption.
Subject(s)
Arthroscopy/methods , Bupivacaine/administration & dosage , Pain, Postoperative/drug therapy , Rotator Cuff/surgery , Tendon Injuries/surgery , Acromion , Adult , Aged , Anesthetics, Local/administration & dosage , Double-Blind Method , Female , Follow-Up Studies , Humans , Infusion Pumps , Male , Middle Aged , Pain Management , Pain Measurement , Pain, Postoperative/diagnosis , Rotator Cuff Injuries , Treatment OutcomeABSTRACT
The Pyk2 tyrosine kinase can be activated by both calcium-dependent and calcium-independent mechanisms. Exposure to moderate hypoxia (5% O(2)) induced a rapid and persistent tyrosine phosphorylation of Pyk2 in pheochromocytoma (PC12) cells. Hypoxia and KCl-depolarization increased the phosphotyrosine content of Pyk2 by twofold and fourfold, respectively. Both of these effects were abolished in the absence of extracellular calcium. There was a modest activation of MAPK in parallel with the onset of Pyk2 phosphorylation. However, there was no detectable activation of either JNK or c-src, two other known downstream targets of Pyk2. Thus, exposure to hypoxia may selectively target specific subsets of Pyk2 signalling pathways.
