The Influence of Bupivacaine Temperature on Supraclavicular Plexus Block Characteristics: A Randomized, Controlled Trial.

BACKGROUND: Changes in local anesthetics temperature may influence the characters of the peripheral nerve block. The effect of warmed bupivacaine on supraclavicular brachial plexus block has not yet been evaluated. OBJECTIVES: This study was designed to evaluate the influence of warming bupivacaine 0.5% on the characteristics of supraclavicular plexus block in adult patients undergoing orthopedic surgery below the mid-arm. The primary objective was the time to onset of sensory block. The secondary objectives were the time to onset of motor block, the duration of sensory and motor blocks, and the time to the first analgesic requirement. STUDY DESIGN: Randomized, double-blind, controlled trial. SETTING: University hospital setting. METHODS: Ninety patients who underwent elective or emergency orthopedic surgery below the mid-arm were included in this study. Patients were randomly allocated into 2 groups and received ultrasound-guided supraclavicular brachial plexus block. Group I received 30 mL 0.5% bupivacaine at 23°C. Group II received 30 mL bupivacaine 0.5% warmed to 37°C. The onset of sensory and motor blocks, postoperative pain severity, the duration of sensory and motor blocks, and the time to the first analgesic requirement were evaluated in all patients. RESULTS: The warm bupivacaine group had a significantly accelerated onset time of sensory and motor block. The duration of sensory and motor block and the time to first requirement for analgesia were significantly longer in the warm bupivacaine group. Moreover, it significantly reduced the postoperative analgesics consumption. LIMITATIONS: Postoperative assessment of the offset of the sensory and motor blocks of the individualized nerves was inaccessible, in addition to a small sample size. CONCLUSIONS: Warming bupivacaine 0.5% to 37°C improves the characteristics of supraclavicular plexus block. It promotes rapid onset of sensory-motor block and provided better quality of postoperative analgesia.

Ultrasound-guided Pulsed Radiofrequency in the Management of Thoracic Postherpetic Neuralgia: A Randomized, Double-blinded, Controlled Trial.

OBJECTIVES: This study was designed to evaluate the efficacy and safety of ultrasound-guided pulsed radiofrequency (PRF) for the intercostal nerves (ICNs) in the management of thoracic postherpetic neuralgia. METHODS: After 2 weeks of treatment by pregabalin 150 mg/12 hours, patients were randomly allocated into 2 groups. The PRF group, after ultrasound-guided localization of the ICN of the affected thoracic dermatome, sensory stimulation of the ICN was tested. Thereafter, the patient received 2 cycles PRF at 42°C temperature, for 120 seconds. The sham group, after stimulation, the same time was spent to mimic PRF. The same procedures were repeated to the upper and lower adjacent ICNs. Pain intensity using Visual Analogue Scale (VAS), and total analgesics consumption were assessed at the baseline, every 2 weeks for 6 months then after 9 and 12 months. The duration of effective pain relief was recorded. Quality of life was evaluated using self-evaluation questionnaires (SF-36) at baseline then after 1, 3, 6, and 12 months. RESULTS: PRF group expressed a significant decrease on the VAS throughout the study period. VAS<30 was reported in the PRF group until the 22nd week. Pregabalin and acetaminophen consumption was significantly lower in the PRF group. The 8 domains of the SF-36 revealed a significant improvement in the PRF group when compared with the sham group throughout the study period except for the physical role which displayed nonsignificant improvement. CONCLUSIONS: Ultrasound-guided PRF for ICNs in combination with pharmacotherapy seems to be a safe and effective treatment modality for postherpetic neuralgia.