In patients undergoing fast track total knee arthroplasty, addition of buprenorphine to a femoral nerve block has no clinical advantage: A prospective, double-blinded, randomized, placebo controlled trial.

BACKGROUND: Several adjuvants have been proposed to prolong the effect of peripheral nerve blocks, one of which is buprenorphine. In this randomized double blinded placebo controlled trial we studied whether the addition of buprenorphine to a femoral nerve block prolongs analgesia in patients undergoing total knee arthroplasty in a fast track surgery protocol. METHODS: The treatment group (B) was given an ultrasound-guided femoral nerve block with ropivacaine 0.2% and 0.3mg buprenorphine. We choose to use 2 control groups. Group R was given a femoral nerve block with ropivacaine 0.2% only. Group S also received 0.3 mg buprenorphine subcutaneously. Only patients with a successful block were enrolled in the study. RESULTS: We found no difference in our primary outcome parameter of time to first rescue analgesic. We found lower opioid use and better sleep quality the first postoperative night in patients receiving buprenorphine perineurally or subcutaneously. Buprenorphine did not lead to any significant change in pain or mobilization. We found a high overall incidence of nausea and vomiting. CONCLUSION: In patients undergoing total knee arthroplasty, in the setting of a fast track surgery protocol, the addition of buprenorphine to a femoral nerve block did not prolong analgesia.

Influence of arm position on ultrasound visibility of the axillary brachial plexus.

BACKGROUND: Contemporary axillary brachial plexus block is performed by separate injections targeting radial, median, ulnar and musculocutaneous nerve. These nerves are arranged around the axillary artery, making ultrasound visualisation sometimes challenging. In particular, the radial nerve can be difficult to localise deep to the artery. OBJECTIVES: The primary aim of this study was to investigate which arm position optimises the visibility of the radial nerve. Secondary aims were the visibility and position of the other nerves during varying arm positions. DESIGN: A prospective observational study. SETTING: University teaching hospital, November 2012. PARTICIPANTS: Twenty volunteers, recruited by an advertisement on the Department's bulletin board. Inclusion criterion age more than 18 years. EXCLUSION CRITERIA: refusal of ultrasound examination, restricted shoulder movement, local infection, BMI greater than 30 kg m⁻². INTERVENTION: One anaesthesiologist performed bilateral ultrasound examinations of the axillary brachial plexus on 20 volunteers. Each arm was placed in different positions [shoulder (S) 90° or 180° abduction, elbow (E) 0° or 90° extension] and scans were performed proximally in the axilla, and additionally 5 cm distally to this point [proximal (P) vs. distal (D)], resulting in eight different scans stored for off-line analysis performed by two blinded anaesthesiologists. MAIN OUTCOME MEASURES: For radial, median, ulnar and musculocutaneous nerve, visibility was assessed on a six-point visibility scale. Distances and angles of the nerves relative to the axillary artery and distances relative to the skin were measured. RESULTS: No significant differences between arm positions were found in the visibility score of radial (P = 0.359) and musculocutaneous nerves (P = 0.073). Visibility of the median nerve was improved in positions S90°/E0°/D and S180°/E0°/P (P = 0.02). The ulnar nerve was more visible in position S180°/E 0°/P and D (P = 0.007). The greatest distance between artery and radial nerve was 7.4 ±â€Š4.7 mm at an angle of 120 ±â€Š14° in position S180°/E 0°/D. CONCLUSION: The visibility of the radial nerve was not improved by varying positions of the arm. S180°/E0° provided the best overall visibility and accessibility of nerves. TRIAL REGISTRATION: https://www.toetsingonline.nl/to/ccmo_search.nsf/Searchform?OpenForm Identifier: NL42116.018.12.

Combining paracetamol (acetaminophen) with nonsteroidal antiinflammatory drugs: a qualitative systematic review of analgesic efficacy for acute postoperative pain.

BACKGROUND: There has been a trend over recent years for combining a nonsteroidal antiinflammatory drug (NSAID) with paracetamol (acetaminophen) for pain management. However, therapeutic superiority of the combination of paracetamol and an NSAID over either drug alone remains controversial. We evaluated the efficacy of the combination of paracetamol and an NSAID versus either drug alone in various acute pain models. METHODS: A systematic literature search of Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, and PubMed covering the period from January 1988 to June 2009 was performed to identify randomized controlled trials in humans that specifically compared combinations of paracetamol with various NSAIDs versus at least 1 of these constituent drugs. Identified studies were stratified into 2 groups: paracetamol/NSAID combinations versus paracetamol or NSAIDs. We analyzed pain intensity scores and supplemental analgesic requirements as primary outcome measures. In addition, each study was graded for quality using a validated scale. RESULTS: Twenty-one human studies enrolling 1909 patients were analyzed. The NSAIDs used were ibuprofen (n = 6), diclofenac (n = 8), ketoprofen (n = 3), ketorolac (n = 1), aspirin (n = 1), tenoxicam (n = 1), and rofecoxib (n = 1). The combination of paracetamol and NSAID was more effective than paracetamol or NSAID alone in 85% and 64% of relevant studies, respectively. The pain intensity and analgesic supplementation was 35.0% +/- 10.9% and 38.8% +/- 13.1% lesser, respectively, in the positive studies for the combination versus paracetamol group, and 37.7% +/- 26.6% and 31.3% +/- 13.4% lesser, respectively, in the positive studies for the combination versus the NSAID group. No statistical difference in median quality scores was found between experimental groups. CONCLUSION: Current evidence suggests that a combination of paracetamol and an NSAID may offer superior analgesia compared with either drug alone.

The analgesic efficacy of intravenous versus oral tramadol for preventing postoperative pain after third molar surgery.

PURPOSE: The aim of this study was to compare the analgesic efficacy of single-dose preoperative intravenous versus oral tramadol for preventing pain after third molar surgery. PATIENTS AND METHODS: Seventy-two patients undergoing elective third molar surgery were randomized to receive either intravenous (n = 36) or oral (n = 36) tramadol 50 mg. The intravenous group received an oral placebo capsule followed by intravenous tramadol 50 mg preoperatively. The oral tramadol group received a 50-mg oral tramadol capsule followed by intravenous placebo saline preoperatively. In both groups, a standard intravenous sedation technique was administered and the impacted third molars were removed under local anesthesia. The difference in postoperative pain was assessed by 4 primary end points: hourly pain intensity as measured by a 100-mm visual analog scale for 8 hours, time to rescue analgesic, postoperative acetaminophen consumption, and a 5-point global assessment scale (0 = poor, 1 = fair, 2 = good, 3 = very good, and 4 = excellent). RESULTS: Throughout the 8-hour investigation period, patients reported significantly lower pain intensity scores in the intravenous versus oral group (15.9 +/- 9.6 mm versus 36.9 +/- 17.2 mm, P = .03). Patients also reported significantly longer time to rescue analgesic (7.0 hours versus 3.5 hours, P = .00001), lesser postoperative acetaminophen consumption (1,823 +/- 1,266 mg versus 3,558 +/- 1,418 mg, P = .000006), and better global assessment (2.6 +/- 0.9 versus 1.1 +/- 0.8, P = .01) for the intravenous versus oral group. CONCLUSIONS: We conclude that preoperative intravenous tramadol is superior to oral tramadol for preventing postoperative pain following third molar surgery. However, it should be noted that there is a difference in the bioavailability between the 2 formulations of up to 30%, which may explain the findings.