Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis.

STUDY OBJECTIVE: To determine if the use of ultrasound guidance (vs non-ultrasound techniques) improves the success rate of nerve blocks. DESIGN: Meta-analysis of randomized controlled trials (RCTs) in the published literature. SETTING: University medical center. MEASUREMENTS: 16 RCTs of patients undergoing elective surgical procedures were studied. Patients underwent ultrasound-guided or non-ultrasound techniques (nerve stimulation, surface landmark) for peripheral nerve blocks. Success rates were measured. MAIN RESULTS: Ultrasound guidance (vs all non-ultrasound techniques) was associated with a significant increase in the success rate of nerve blocks [relative risk (RR) = 1.11 (95% confidence interval [CI]: 1.06 to 1.17, P < 0.0001]). When compared with nerve stimulator techniques only, ultrasound guidance was still associated with an increase in the success rate (RR = 1.11 [95% CI: 1.05 to 1.17, P = 0.0001]). For specific blocks, ultrasound guidance (vs all non-ultrasound) was associated with a significant increase in successful brachial plexus (all) nerve blocks (RR = 1.11 [95% CI: 1.05 to 1.20, P = 0.0001]), sciatic popliteal nerve block (RR = 1.22 [95% CI: 1.08 to 1.39, P = 0.002]) and brachial plexus axillary nerve block (RR = 1.13 [95% CI: 1.00 to 1.26, P = 0.05]) but not brachial plexus infraclavicular nerve block (RR = 1.25 [95% CI: 0.88 to 1.76, P = 0.22]). CONCLUSIONS: Ultrasound-guided peripheral nerve block is associated with an increased overall success rate when compared with nerve stimulation or other methods. Ultrasound-guided techniques also increase the success rate of some specific blocks.

Meta-analysis of the effect of extended-release epidural morphine versus intravenous patient-controlled analgesia on respiratory depression.

OBJECTIVE: Extended-release epidural morphine (EREM) is a single-dose, extended-release epidural morphine formulation intended to provide postoperative pain relief over a 48-hour period. There have been a few randomized controlled trials investigating the use and safety of EREM versus intravenous patient-controlled analgesia with opioids (IV-PCA); however, the adverse event of respiratory depression of this treatment is unclear. The authors have undertaken a meta-analysis to examine this issue. METHODS: A systematic literature search of the National Library of Medicine's PubMed database was conducted for terms related to EREM. Only randomized controlled trials, in the English language, assessing the rates of respiratory depression of EREM to IV-PCA were included for analysis. Data on pertinent study characteristics and relevant outcomes were extracted from accepted articles. Meta-analysis was performed using the Review Manager 4.2.7 (The Cochrane Collaboration, 2004). A random effects model was used. RESULTS: The authors' literature search yielded three articles which met all inclusion criteria. All studied doses of EREM were evaluated. Pooled estimates (odds ratio) were made for rates of adverse events of respiratory depression. Use of EREM was associated with significantly higher odds of respiratory depression compared to IV-PCA (odds ratio = 5.74; 95% confidence interval: 1.08, 30.54, p = 0.04). Even when examining only Food and Drug Administration approved dosages for EREM, the use of EREM was associated with significantly higher odds of respiratory depression when compared with IV-PCA (odds ratio = 5.80; 95% confidence interval: 1.05, 31.93, p = 0.04). CONCLUSIONS: Although perioperative single-dose epidural EREM (versus IV-PCA) was effective for postoperative pain relief for up to 48 hours, it is associated with significantly higher odds of respiratory depression. Further examination of the issue of respiratory depression of epidural EREM may be warranted.

Pregabalin as a treatment for painful diabetic peripheral neuropathy: a meta-analysis.

BACKGROUND AND OBJECTIVES: Painful diabetic peripheral neuropathy (DPN) is an increasingly prevalent disorder that is best managed through a multimodal approach. We examined the effects of pregabalin on pain control, sleep disturbance, and the patient's global impression of change (PGIC) for the treatment of this disorder. METHODS: Studies were identified using the National Library of Medicine's PubMed and EMBase databases (1966 to July 15, 2007). Inclusion criteria were randomized trials comparing pregabalin to placebo in the treatment of DPN for adult patients. A total of 13 abstracts were identified of which 3 met inclusion criteria. Data were collected from each article and results were recorded. Primary outcome was pain at the conclusion of the study. Secondary outcomes included number of patients with 50% reduction in mean pain score, PGIC ratings at endpoint, and adverse events. A random-effects model was used. RESULTS: The 3 studies yielded 728 total subjects from 5 centers, of which 476 received pregabalin (dose range 75 to 600 mg/day) and 252 received placebo. Pregabalin treatment was associated with a significant decrease in pain scores (weighted mean difference, 1.15), higher likelihood to achieve at least a 50% reduction in mean pain score (relative risk [RR], 4.05), and improved PGIC ratings (RR = 1.45). Pregabalin was associated with an increased risk of somnolence, dizziness, and edema. CONCLUSIONS: Pregabalin has significant effects on the pain associated with DPN as well as secondary endpoints that affect patients' quality of life.