Levobupivacaine 0.5% provides longer analgesia after sciatic nerve block using the Labat approach than the same dose of ropivacaine in foot and ankle surgery.

BACKGROUND: Levobupivacaine and ropivacaine are 2 left enantiomeric molecules frequently used for peripheral nerve blocks because of their safe clinical profile. Levobupivacaine is more lipophilic and theoretically more potent than ropivacaine, but clinical studies show conflicting results in terms of anesthetic and analgesic characteristics. We hypothesized that the pure S-enantiomer of bupivacaine provides longer-lasting analgesia than ropivacaine. METHODS: We compared the analgesic characteristics of 20 mL levobupivacaine versus 20 mL ropivacaine 0.5% in a posterior sciatic nerve block (Labat approach) for foot and ankle surgery. In a double-blind, randomized, prospective design, 80 patients received either substance. We assessed the onset, duration, and success of the block, and the need for rescue analgesia and technical or neurologic complications over 24 hours. RESULTS: The onset of sensory block (minutes) and the success rate were similar in levobupivacaine and ropivacaine groups (onset, 15 minutes [5-40 minutes] vs 15 minutes [5-60 minutes], respectively; success rate, 90% vs 92.5%). The average time for the first request of pain medication provided by 20 mL levobupivacaine 0.5% was significantly longer than with ropivacaine (1605 minutes [575-2400 minutes] vs 1035 minutes [590-1500 minutes], P < 0.001). The need for postoperative rescue analgesia was higher in the ropivacaine group (37 of 40 [92.5%] vs 30 of 40 [75%], P < 0.034). No complications were noted in either group at 24 hours. CONCLUSION: Twenty milliliters levobupivacaine 0.5% in posterior gluteal (Labat) sciatic nerve block provided longer-lasting analgesia after foot and ankle surgery compared with the same dose of ropivacaine.

Comparison of fresh and Thiel's embalmed cadavers according to the suitability for ultrasound-guided regional anesthesia of the cervical region.

INTRODUCTION: Ultrasound-guided punctures are a new technique in anesthesia. However, training in these techniques requires conditions resembling real life as far as possible for learning purposes. Several models are available, but none associates realistic anatomy and lifelike sensations of the passage of fascias. The aim of our study was to compare fresh and Thiel's embalmed cadavers for ultrasound-guided punctures. METHODS: Eight fresh cadavers and eight Thiel's embalmed cadavers were investigated. The cervical region was scanned with an ultrasound probe. Age, sex and body mass index (BMI) were recorded. Visibility of he structures, including sternocleidomastoid (SCM) muscle, anterior and middle scalene muscles, thyroid gland, nerve and the needle, was evaluated as 0 (not visible or bad visibility) or 1 (good visibility). The feeling ("pop") of passing the fascias was noted as 0 (not felt) or 1 (felt). The possibility of nerve displacement with the needle, the difficulty of intraneural injection and the possibility of nerve penetration and nerve swelling were all recorded as 0 (not possible) or 1 (possible). RESULTS: The two groups were comparable in terms of sex, age and BMI. Visibility of the SCM muscle and the needle was better in the Thiel group. Moreover, the "pop" feeling and nerve swelling were significantly more frequently present in the Thiel group. There was no significant difference in terms of the other results between the two groups. CONCLUSIONS: Cadavers embalmed according to Thiel's method should be recommended for ultrasound-guided punctures as a realistic and lifelike model.

Perineural clonidine does not prolong levobupivacaine 0.5% after sciatic nerve block using the Labat approach in foot and ankle surgery.

BACKGROUND: There is controversy about the effectiveness of perineural clonidine used as an adjuvant to local anesthetics. This study investigated whether the addition of 150 µg clonidine to 0.5% levobupivacaine used for posterior sciatic nerve block would prolong the duration of analgesia. METHODS: This double-blind, prospective trial compared the analgesic characteristics of 20 mL plain levobupivacaine versus 20 mL levobupivacaine 0.5% plus 150 µg clonidine in a posterior sciatic nerve block (Labat approach) for foot and ankle surgery. Sixty patients were randomized and allocated to receive either levobupivacaine alone or levobupivacaine plus clonidine, to find a 30% prolongation of analgesia with the adjuvant, using the same SD. The onset and duration of the block (time from completion of block administration to first morphine request), the hemodynamic changes during surgery, the need for rescue analgesia, and technical or neurologic complications were assessed over a 24-hour period. RESULTS: The onset of sensory block (in minutes) was similar in the levobupivacaine and levobupivacaine plus clonidine groups (10 [5-20] vs 10 [5-23] minutes, median [interquartile range], respectively), as was the time to first request of pain medication (1215 [920-1530] vs 1275 [1067-1360] minutes, respectively). However, during surgery, statistically significantly more subjects in the levobupivacaine plus clonidine group than the levobupivacaine group experienced a decrease of more than 20% in systolic arterial pressure (50% vs 28% of patients, respectively; P < 0.028). No complications were noted in either group over 24 hours. CONCLUSIONS: Addition of 150 µg clonidine to 20 mL of levobupivacaine 0.5% in posterior gluteal (Labat) sciatic nerve block did not prolong the duration of analgesia but had a slight effect on systolic arterial pressure.

Isobaric versus hypobaric spinal bupivacaine for total hip arthroplasty in the lateral position.

UNLABELLED: Total hip arthroplasty (THA) is frequently performed under spinal anesthesia using either isobaric or hypobaric anesthetic solution. However, these two solutions have never been compared under similar surgical conditions. In the present study, we compared the anesthetic and hemodynamic effects of isobaric and hypobaric bupivacaine in 40 ASA physical status I-II patients undergoing THA in the lateral decubitus position under spinal anesthesia. With operative side up, patients randomly received, in a double-blinded manner, a spinal injection of 3.5 mL (17.5 mg) of plain bupivacaine mixed with either 1.5 mL of normal saline (isobaric group) or 1.5 mL of distilled water (hypobaric group). Sensory level and degree of motor block were evaluated on the nondependent and dependent sides until regression to L2 and total motor recovery. Hemodynamic changes during the first 45 min after spinal injection, and the time between spinal administration and first analgesic for a pain score >3 (on a 0-10 scale) were noted. Demographic characteristics of both groups were comparable. Upper sensory level and maximal degree of motor block were comparable between the operative and nonoperative sides in each group and between corresponding sides in both groups. Compared with the isobaric group, in the hypobaric group there was a prolonged time to sensory regression to L2 on the operative side (287 +/- 51 versus 242 +/- 36 min, P < 0.004) and a prolonged time to first analgesic (290 +/- 46 versus 237 +/- 39 min, P < 0.001). No difference in quality of motor block was noted at the end of surgery. Hemodynamic changes were comparable. We conclude that for THA in the lateral position, spinal hypobaric bupivacaine seems to be superior to isobaric in that it prolongs the sensory block on the operative side and delays the use of analgesics after surgery without further compromising hemodynamic stability. IMPLICATIONS: For total hip arthroplasty in the lateral position, spinal hypobaric bupivacaine compared with isobaric prolonged sensory block at the operative side and delayed the time to first analgesic.