A randomized comparison between intravenous and perineural dexamethasone for ultrasound-guided axillary block.

BACKGROUND: This randomized double-blinded trial compared the effect of intravenous and perineural dexamethasone (8 mg) on the duration of motor block for ultrasound (US)-guided axillary brachial plexus block (AXB). METHODS: Patients undergoing upper limb surgery with US-guided AXB were randomly allocated to receive preservative-free dexamethasone (8 mg) via intravenous (n = 75) or perineural (n = 75) administration. The local anesthetic agent, 1% lidocaine -0.25% bupivacaine (30 mL) with epinephrine 5 µg·mL-1, was identical in all subjects. Operators and patients were blinded to the nature of the intravenous and perineural injectate. A blinded observer assessed the block success rate (i.e., a minimal sensorimotor composite score of 14 out of 16 points at 30 min), block onset time, as well as the presence of surgical anesthesia. Postoperatively, the blinded observer contacted all patients with successful blocks to record the duration of motor block (primary outcome), sensory block, and postoperative analgesia. RESULTS: No intergroup differences were observed in terms of success rate, surgical anesthesia, and block onset time. Compared to intravenous administration, perineural dexamethasone provided longer mean (SD) durations for motor block [17.5 (4.6) hr vs 12.8 (4.5) hr; mean difference, 4.6 hr; 95% confidence interval [CI], -6.21 to -3.08; P < 0.001], sensory block [17.7 (5.1) hr vs 13.7 (5.0) hr; mean difference, 4.0 hr; 95% CI, -5.77 to -2.27; P < 0.001], and postoperative analgesia [21.1 (4.6) hr vs 17.1 (4.6) hr; mean difference, 4.0 hr; 95% CI, -5.70 to -2.30; P < 0.001]. CONCLUSION: Compared to intravenous dosing, perineural dexamethasone (8 mg) results in longer durations of sensorimotor block and postoperative analgesia for ultrasound-guided axillary block. This trial was registered at www.clinicaltrials.gov number, NCT02629835.

Rare adverse effect of spinal cord stimulation: micturition inhibition.

OBJECTIVES: In current medical literature, most of the reported complications of spinal cord stimulation concern technical problems, such as lead malfunction, migration, breakage, or internal pulse generator dysfunction, whereas reports about the side effects on internal organ function caused by spinal cord stimulation are rare. METHODS: In this clinical report, we describe uncommon side effects owing to spinal cord stimulation in a patient with chronic neuropathic pain. Our patient developed unexpected urinary retention during electrical epidural stimulation. RESULTS AND DISCUSSION: This case report highlights the incomplete knowledge about the mechanism of action of spinal cord stimulation and its influence on the interactions between the autonomic nervous system and voluntary control of urinary function. The complete recovery of bladder function after the interruption of stimulation suggests that electrical stimulation caused the adverse effects in this clinical case.

Intraoperative infusion of lidocaine reduces postoperative fentanyl requirements in patients undergoing laparoscopic cholecystectomy.

BACKGROUND: Lidocaine has been shown to inhibit neural conduction and to have anti-inflammatory properties. The purpose of this study was to determine whether intraoperative lidocaine infusion reduces opioid consumption in the postanesthesia care unit (PACU). METHODS: Fifty patients were enrolled in this prospective, randomized and observer-blinded study. At induction of anesthesia the control group (n = 25) received fentanyl 3 microg.kg(-1) while the lidocaine group received fentanyl 1.5 microg.kg(-1) and a bolus of lidocaine 1.5 mg.kg(-1) followed by a continuous infusion of lidocaine 2 mg.kg(-1).hr(-1). General anesthesia included propofol, rocuronium, and desflurane titrated to maintain blood pressure and heart rate within set parameters, and the bispectral index between 35 and 50. No supplemental opioids were given during surgery. All patients received acetaminophen, ketorolac, dexamethasone, droperidol and local anesthetics in the skin incision. Patients received fentanyl and ondansetron in the PACU. The primary outcome variable was the amount of fentanyl required in the PACU to establish and to maintain visual analogue scale pain scores < 3. RESULTS: Most patients received fentanyl for pain relief in the PACU, but the cumulative mean dose was lower in the lidocaine group compared to the control group (98 +/- 54 microg, vs 154 +/- 99 microg, respectively, P = 0.018). Lidocaine infusion reduced by 10% the amount of desflurane required (P = 0.012). White-Song scores > 12 were attained by all patients in both groups within 30 min of their arrival in the PACU. Median time from arrival to the PACU to discharge home was similar in both groups, 167.5 min in the control group vs 180 min in the lidocaine group (P = 0.649). CONCLUSION: Intraoperative lidocaine infusion reduces opioid consumption in the PACU and intraoperative requirements of desflurane.