Buprenorphine added to the local anesthetic for axillary brachial plexus block prolongs postoperative analgesia

BACKGROUND AND OBJECTIVES: Buprenorphine added to local anesthetic solutions for supraclavicular block was found to triple postoperative analgesia duration in a previous study when compared with local anesthetic block alone. That study, however, did not control for potentially confounding factors, such as the possibility that buprenorphine was affecting analgesia through intramuscular absorption or via a spinal mechanism. To specifically delineate the role of buprenorphine in peripherally mediated opioid analgesia, the present study controlled for these 2 factors. METHODS: Sixty American Society of Anesthesiologists (ASA) P.S. I and II, consenting adults for upper extremity surgery, were prospectively assigned randomly in double-blind fashion to 1 of 3 groups. Group I received local anesthetic (1% mepivacaine, 0.2% tetracaine, epinephrine 1:200,000), 40 mL, plus buprenorphine, 0.3 mg, for axillary block, and intramuscular (IM) saline. Group II received local anesthetic-only axillary block, and IM buprenorphine 0.3 mg. Group III received local anesthetic-only axillary block and IM saline. Postoperative pain onset and intensity were compared, as was analgesic medication use. RESULTS: The mean duration of postoperative analgesia was 22.3 hours in Group I; 12.5 hours in group II, and 6.6 hours in group III. Differences between groups I and II were statistically significant (P =.0012). Differences both between groups I and III and II and III were also statistically significant (P <.001). CONCLUSIONS: Buprenorphine-local anesthetic axillary perivascular brachial plexus block provided postoperative analgesia lasting 3 times longer than local anesthetic block alone and twice as long as buprenorphine given by IM injection plus local anesthetic-only block. This supports the concept of peripherally mediated opioid analgesia by buprenorphine.     

Clonidine combined with a long acting local anesthetic does not prolong postoperative analgesia after brachial plexus block but does induce hemodynamic changes

Clonidine in brachial plexus block prolongs analgesia of local anesthetics of short and intermediate duration. We performed a prospective randomized double-blinded study to determine the efficacy and adverse effects of clonidine mixed with a long-acting local anesthetic on postoperative analgesia. Sixty adult patients underwent elective rotator cuff repair using interscalene brachial plexus block combined with general anesthesia and were randomly divided into one of the following three groups. Placebo (n = 20): interscalene block with 40 mL of 0.5% bupivacaine with epinephrine (1/200000) and 1 mL of 0.9% saline, completed by 1 mL of 0.9% saline IM in the controlateral shoulder; Control (n = 20): interscalene block with 40 mL of 0.5% bupivacaine with epinephrine and 1 mL of 0. 9% saline, completed by 150 microg (=1 mL) of clonidine IM; Clonidine (n = 20): interscalene block with 40 mL of 0.5% bupivacaine with epinephrine and 150 microg (=1 mL) of clonidine, completed by 1 mL of 0.9% saline IM. During anesthesia hemodynamic variables and fractional expired isoflurane concentration (FeISO) were recorded. The following postoperative variables were assessed: duration of interscalene block, quality of pain relief on a visual analog scale, side effects, and consumption of morphine with a patient-controlled analgesia device over 48 h. Patient characteristics were comparable. During anesthesia mean arterial pressure, heart rate, and FeISO were significantly decreased in Clonidine and Control groups compared with Placebo group. Duration of analgesia, defined as the time elapsed from interscalene injection to the first morphine request, was 983 +/- 489 min in the Placebo, 909 +/- 160 min in the Control, and 829 +/- 159 min in the Clonidine groups. Pain scores and consumption of morphine at 24 h and 48 h showed no differences among the three groups. We conclude that adding 150 microg of clonidine in interscalene block does not prolong analgesia induced by 40 mL of bupivacaine 0.5% with epinephrine, but decreases mean arterial blood pressure and heart rate. Implications: Clonidine in brachial plexus block does not improve postoperative analgesia when mixed with a long-lasting anesthetic. Nevertheless, with or without clonidine, bupivacaine in interscalene block provides a long-lasting analgesia of approximately 15 h.     

Addition of fentanyl to bupivacaine prolongs anesthesia and analgesia in axillary brachial plexus block

BACKGROUND AND OBJECTIVES: To evaluate the analgesic and anesthetic effects of 40 mL bupivacaine 0.25%, 40 mL bupivacaine 0.25% plus fentanyl 2.5 microg/mL, and 40 mL bupivacaine 0.125% plus fentanyl 2.5 microg/mL for axillary brachial plexus block. METHODS: Sixty patients were randomly allocated to 3 groups and received axillary brachial plexus block with 40 mL bupivacaine 0.25% (group B), 40 mL bupivacaine 0.25% with fentanyl 2.5 microg/mL (group BF), or 40 mL bupivacaine 0.125% with fentanyl 2.5 microg/mL (group DBF). The onset times and the duration of sensory and motor blocks, duration of analgesia, hemodynamic parameters, and adverse events were noted. RESULTS: The mean duration of sensory block and analgesia were longer in group BF (10.1 hours and 20.9 hours) than group B (6.9 hours and 11.6 hours) and DBF (5.9 hours and 12.0 hours) (P < .01, P < .001, respectively). The mean duration of motor block was also longer in group BF (10.7 hours) than group B (4.9 hours) (P < .01). Only 2 patients experienced motor block in group DBF. The frequency of successful block was 35% in group DBF (P < .01). Hemodynamic parameters were similar in all groups. In group B, only 1 patient experienced dizziness. Nausea was observed in 1 patient in each fentanyl group. CONCLUSION: The addition of 100 microg/mL fentanyl to 0.25% bupivacaine almost doubles the duration of analgesia following axillary brachial plexus block when compared with 0.25% bupivacaine alone.     

Tramadol added to 1.5% mepivacaine for axillary brachial plexus block improves postoperative analgesia dose-dependently

Adjuncts to local anesthetics for peripheral plexus blockade may enhance the quality and duration of anesthesia and postoperative analgesia. The analgesic, tramadol, has a unique mechanism of action that suggests efficacy as such an adjunct. It displays a central analgesic and peripheral local anesthetic effect. We designed a prospective, randomized, controlled and double-blind clinical trial to assess the effect of tramadol added to brachial plexus anesthesia. One-hundred patients scheduled for carpal tunnel release surgery under brachial plexus anesthesia were randomized into four groups. All patients received 1.5% mepivacaine 40 mL plus a study solution containing either isotonic sodium chloride (Group P, n = 17), tramadol 40 mg (Group T(40), n = 22), tramadol 100 mg (Group T(100), n = 20) or tramadol 200 mg (Group T(200), n = 20). We evaluated the time of onset of anesthesia, duration of sensory and motor blockade, duration and quality of postoperative analgesia, and occurrence of adverse effects. Onset and duration of sensory and motor blocks were not different among groups. The number of patients requesting analgesia in the postoperative period was significantly less in the 3 tramadol groups compared with the placebo group (P = 0.02); this was also noted with the placebo and T(40) groups compared with the T(200) group. No statistical significance was demonstrated between the placebo and the T(40) group or the T(100) group and the T(200) group. Furthermore, there was a significant trend effect among groups applying the Cochran-Armitage tendency test (P = 0.003), suggesting a dose-dependent decrease for additional postoperative analgesia requirements when tramadol was added. Side effects did not differ among groups, although they were more frequently recorded in the T groups. Our study suggests that tramadol added to 1.5% mepivacaine for brachial plexus block enhances in a dose-dependent manner the duration of analgesia with acceptable side effects. However, the safety of tramadol has to be investigated before allowing its use in clinical practice. IMPLICATIONS: Tramadol's unique mechanism of action suggests efficacy as a local anesthetic adjunct for peripheral plexus blockade. Our study demonstrates that tramadol, added to mepivacaine for brachial plexus anesthesia, extends the duration and improves the quality of postoperative analgesia in a dose dependent fashion with acceptable side effects.     

Spinal anesthetic agents

Lidocaine, tetracaine, and bupivacaine are the local anesthetic agents most commonly employed for spinal anesthesia in the U.S. Lidocaine provides a short duration of anesthesia and is primarily useful for surgical and obstetrical procedures lasting less than one hour. Tetracaine and bupivacaine are used for procedures lasting 2 to 5 hours. Tetracaine appears to provide a somewhat longer duration of anesthesia and a more profound degree of motor block than does bupivacaine. On the other hand, compared with tetracaine, bupivacaine has been demonstrated to be associated with a decreased incidence of hypotension. In addition, bupivacaine may be better than tetracaine for use in orthopedic surgical procedures since it appears to be associated with a lower incidence of tourniquet pain. Vasoconstrictors can prolong the duration of spinal anesthesia of all three agents. However, the greatest duration is seen when vasoconstrictors are added to tetracaine solutions. Lidocaine and bupivacaine do not appear to benefit as much from the addition of vasoconstrictors. In general, the local anesthetic agents that are currently available for spinal anesthesia provide significant versatility. By carefully considering the planned surgical procedure, the surgeon's requirements, and the patient's characteristics (e.g., age, height, gravidity), and by understanding the factors that influence spinal anesthesia, the anesthesiologist can select a local anesthetic agent that will assure adequate and satisfying spinal anesthesia.     

Caudal block in children: ropivacaine compared with bupivacaine.

BACKGROUND: Bupivacaine provides reliable, long-lasting anesthesia and analgesia when given via the caudal route. Ropivacaine is a newer, long-acting local anesthetic that (at a concentration providing similar pain relief) has less motor nerve blockade and may have less cardiotoxicity than bupivacaine. METHODS: In a double-blind trial, 81 healthy children, undergoing ambulatory surgical procedures, were randomly allocated to receive caudal analgesia with either bupivacaine or ropivacaine, 0.25%, 1 mVkg. All blocks were placed by an attending anesthesiologist or an anesthesia fellow after induction of general anesthesia. RESULTS: Data were available for 75 children. There were no significant differences between the two groups in baseline characteristics or in anesthesia, surgery, recovery room, or day surgery unit durations. The quality and duration of postoperative pain relief did not differ. Motor and sensory effects were similar. Time to first micturition did not differ. CONCLUSION: Ropivacaine (0.25%, 1 ml/kg) provided adequate postoperative analgesia with no difference from bupivacaine (0.25%, 1 ml/kg) in quality and duration of pain relief, motor and sensory effects, or time to first micturition in our study children.     

1．5％甲哌卡因与0．5％布比卡因混合液对超声引导下肌间沟神经阻滞起效时间及镇痛时间的作用

背景一般采用短效与长效局麻药混合使用来达到神经阻滞起效快维持时间长的效果。但是,有关混合使用局麻药优点的数据报道并不多见。我们假设使用甲哌卡因与布比卡因的混合液进行区域阻滞比单纯使用布比卡因起效更快,且比单纯使用甲哌卡因时效更长。方法研究对象为64例行肩关节镜的患者（18-65岁,ASAⅠ-Ⅱ级）,采用超声引导下肌间沟臂丛神经阻滞。受试者随机分配接受3种麻醉药物方案中的1种：1．5％甲哌卡因30ml、0．5％布比卡因30ml、1．5％甲哌卡因15ml与0．5％布比卡因15ml混合液。记录运动和感觉被阻滞的起效时间和维持时间。结果3组腋神经分布区（上干）的感觉阻滞的起效时间相同[甲哌卡因组（8．7±4．3）分钟、布比卡因组（10．0±5．1）分钟、混合液组（11．3±5．3）分钟,组间P=0．21]。运动神经阻滞的持续时间混合液组[（11．5±4．7）小时]位于布比卡因组[（16．4±9．4）小时]和甲哌卡因组[（6．0±4．2）小时]之间。镇痛维持时效最短的是甲哌卡因[（4．9±2．4）小时],最长的是布比卡因组[（14．0±6．2）小时],中间组是混合液组[（10．3±4．9）小时]（甲哌卡因组与混合液组相比,P〈0．001,布比卡因组与混合液组相比,P=0．01）。结论超声引导下肌间沟臂丛神经阻滞时,使用1．5％甲哌卡因与0．5％布比卡因混合液的起效时间与单独使用其中任何一种药物相近,平均阻滞时间明显比单独使用甲哌卡因长,但比布比卡因短。     

Brachial plexus block with midazolam and bupivacaine improves analgesia

PURPOSE: Adjuncts to local anesthetics for brachial plexus block may enhance the quality and duration of analgesia. Midazolam, a water-soluble benzodiazepine, is known to produce antinociception and enhance the effect of local anesthetics when given epidurally or intrathecally. The purpose of this study was to assess the effect of midazolam added to brachial plexus anesthesia. METHODS: A prospective, randomized, double blind study was conducted on 40 ASA I or II adult patients undergoing upper limb surgeries under supraclavicular brachial plexus block. Patients were randomly divided into two groups. Patients in Group B (n = 20) were administered 30 mL of 0.5% bupivacaine and Group BM (n = 20) were given 30 mL of 0.5% bupivacaine with midazolam 50 microg x kg(-1). Hemodynamic variables (i.e., heart rate, noninvasive blood pressure), pain scores and rescue analgesic requirements were recorded for 24 hr postoperatively. RESULTS: The onset of sensory and motor block was significantly faster in Group BM compared to Group B (P < 0.05). Pain scores were significantly higher in Group B compared to Group BM from two hours to 24 hr postoperatively (P < 0.05). Rescue analgesic requirements were significantly less in Group BM compared to Group B (P < 0.05). Hemodynamics and sedation scores did not differ between groups in the post-operative period. CONCLUSION: Midazolam (50 microg x kg(-1)) in combination with 30 mL of bupivacaine (0.5%) hastened onset of sensory and motor block, and improved postoperative analgesia when used in brachial plexus block, without producing any adverse events.     

A comparative study of 0.25% ropivacaine and 0.25% bupivacaine for brachial plexus block.

The present study compares the effectiveness of 0.25% ropivacaine and 0.25% bupivacaine in 44 patients receiving a subclavian perivascular brachial plexus block for upper extremity surgery. The patients were assigned to two equal groups in this randomized, double-blind study; one group received ropivacaine 0.25% (112.5 mg) and the other, bupivacaine 0.25% (112.5 mg), both without epinephrine. Onset times for analgesia and anesthesia in each of the C-5 through T-1 brachial plexus dermatomes did not differ significantly between the two groups. The mean onset time for analgesia ranged from 11.2 to 20.2 min, and the mean onset time for anesthesia ranged from 23.3 to 48.2 min. The onset of motor block differed only with respect to paresis in the hand, with bupivacaine demonstrating a shorter onset time than ropivacaine. The duration of sensory and motor block also was not significantly different between the two groups. The mean duration of analgesia ranged from 9.2 to 13.0 h, and the mean duration of anesthesia ranged from 5.0 to 10.2 h. Both groups required supplementation with peripheral nerve blocks or general anesthesia in a large number of cases, with 9 of the 22 patients in the bupivacaine group and 8 of the 22 patients in the ropivacaine group requiring supplementation to allow surgery to begin. In view of the frequent need for supplementation noted with both 0.25% ropivacaine and 0.25% bupivacaine, we do not recommend using the 0.25% concentrations of these local anesthetics to provide brachial plexus block.     

A combination of buprenorphine and bupivacaine for peridural anesthesia. Our experience

The Authors report the results of a study on 204 patients anesthetized with epidural administration of buprenorphine with bupivacaine. The data obtained were compared with a sample of 236 patients treated with local anesthetic alone. On the whole, the first group of patients presented better anesthesia, with a significantly longer anesthetic effect and more effective sedative and postoperative analgesic effects. Side effects observed were of acceptable entity and incidence.     

Duration and quality of postoperative analgesia after brachial plexus block for shoulder surgery: ropivacaine 0.5% versus ropivacaine 0.5% plus clonidine

OBJECTIVES: Some authors have found that nerve blocks with local anesthetics may last longer if clonidine is added. The present study analyzed the duration and quality of analgesia provided by an interscalene brachial plexus block for shoulder surgery using 0.5% ropivacaine or 0.5% ropivacaine with added clonidine. PATIENTS AND METHODS: Thirty patients were assigned to two groups for double-blind study. The block was performed with 0.5% ropivacaine (40 mL) in group A and with 0.5% ropivacaine (40 mL) and clonidine (40 micrograms) in group B. General anesthesia was provided with propofol in continuous perfusion. Ventilation was spontaneous through a laryngeal mask. After stimulation of the brachial plexus nerves, the anesthesiology administered the assigned drug or drugs. The patient was instructed to remember the time of reversion of the sensory-motor block. Postoperative analgesia was assessed on a visual analog scale at 2, 4, 6, 8 and 24 hours. RESULTS: The mean times until reversion of the sensory-motor block and the assessments of pain at 4, 6, 8 and 24 hours in the two groups were not significantly different. CONCLUSIONS: Adding 40 micrograms of clonidine to 200 mg of 0.5% ropivacaine does not prolong the sensory-motor block or improve the quality of analgesia in the early postoperative period.     

Does bilateral superficial cervical plexus block decrease analgesic requirement after thyroid surgery?

In this randomized, double-blind and controlled study we evaluated and compared the analgesic efficacy of bilateral superficial cervical plexus block and local anesthetic wound infiltration after thyroid surgery. Forty-five patients were assigned to 3 groups. After general anesthesia induction, bilateral superficial cervical plexus block with 0.25% bupivacaine 15 mL in each side was performed in Group I, and local anesthetic wound infiltration with 0.25% bupivacaine 20 mL was performed in Group II. In Group III (control) no regional block was administered. Intravenous patient-controlled analgesia was used to evaluate postoperative analgesic requirement. Neither visual analog scale scores nor total patient-controlled analgesia doses were different among groups. We concluded that bilateral superficial cervical plexus block or local anesthetic wound infiltration with 0.25% bupivacaine did not decrease analgesic requirement after thyroid surgery.     

A comparison of ropivacaine 0.5% and bupivacaine 0.5% for brachial plexus block

This study compared the effectiveness of 0.5% ropivacaine and 0.5% bupivacaine for brachial plexus block. Forty-eight patients received a subclavian perivascular brachial plexus block for upper-extremity surgery. One group (n = 24) received ropivacaine 0.5% (175 mg) and a second group (n = 24) received bupivacaine 0.5% (175 mg), both without epinephrine. Onset times for analgesia and anesthesia in each of the C5 through T1 brachial plexus dermatomes did not differ significantly between groups. Duration of analgesia and anesthesia was long (mean duration of analgesia, 13-14 h; mean duration of anesthesia, 9-11 h) and also did not differ significantly between groups. Motor block was profound, with shoulder paralysis as well as hand paresis developing in all of the patients in both groups. Two patients in each group required supplemental blocks before surgery. Ropivacaine 0.5% and bupivacaine 0.5% appeared equally effective in providing brachial plexus anesthesia.     

Analgesic effect of interscalene block using low-dose bupivacaine for outpatient arthroscopic shoulder surgery

Background and Objectives. Although interscalene brachial plexus block (ISBPB) is often used to provide anesthesia for arthroscopic shoulder surgery, its selective analgesic effect, provided by low-dose local anesthetic, has not been studied. We hypothesized that ISBPB using a low volume and low concentration of bupivacaine can provide effective postoperative analgesia for shoulder surgery without producing significant sensory or motor block elsewhere. Methods. In this double-blind study, 30 outpatients scheduled to undergo shoulder arthroscopy were randomly assigned to receive either an ISBPB with 10 mL 0.125% bupivacaine with epinephrine 1:400,000 (n = 15) or 10 mL of normal saline (n = 15). The block was performed preoperative, prior to a standardized general anesthetic. Postoperative pain scores, morphine and oral analgesic consumption, recovery profile, and patient satisfaction were recorded. Results. In the ISBPB group, verbal analog pain scores within 120 minutes after surgery were lower, morphine consumption in the postanesthesia care unit was significantly lower (2.7 ± 2.6 mg vs 9.5 ± 5.2 mg), the time to postoperative administration of the first systemic or oral analgesic was significantly longer (141 ± 182 minutes vs 13 ± 10 minutes), the degree of motor and sensory block 120 minutes after surgery was minimal, time to reach hospital discharge criteria was earlier, and patient satisfaction with postoperative analgesia at 24-hour follow-up was greater. Thirty-three percent of the patients receiving ISBPB did not require any analgesic prior to hospital discharge. Conclusions. Interscalene brachial plexus block with low-dose bupivacaine is a useful and selective analgesic technique for outpatient shoulder arthroscopic surgery.     

Clonidine combined with small-dose bupivacaine during spinal anesthesia for inguinal herniorrhaphy: a randomized double-blinded study

The aim of this randomized double-blinded study was to see whether the addition of small-dose clonidine to small-dose bupivacaine for spinal anesthesia prolonged the duration of postoperative analgesia and also provided a sufficient block duration that would be adequate for inguinal herniorrhaphy. We randomized 45 patients to 3 groups receiving intrathecal hyperbaric bupivacaine 6 mg combined with saline (Group B), clonidine 15 micro g (Group BC15), or clonidine 30 micro g (Group BC30); all solutions were diluted with saline to 3 mL. The sensory block level was insufficient for surgery in five patients in Group B, and these patients were given general anesthesia. Patients in Groups BC15 and BC30 had a significantly higher spread of analgesia (two to four dermatomes) than those in Group B. Two-segment regression, return of S1 sensation, and regression of motor block were significantly longer in Group BC30 than in Group B. The addition of clonidine 15 and 30 micro g to bupivacaine prolonged time to first analgesic request and decreased postoperative pain with minimal risk of hypotension. We conclude that clonidine 15 micro g with bupivacaine 6 mg produced an effective spinal anesthesia and recommend this dose for inguinal herniorrhaphy, because it did not prolong the motor block. IMPLICATIONS: The addition of clonidine 15 micro g to 6 mg of hyperbaric bupivacaine increases the spread of analgesia, prolongs the time to first analgesic request, and decreases postoperative pain, compared with bupivacaine alone, during inguinal herniorrhaphy under spinal anesthesia.     

Use of bupivacaine as block to relieve postoperative pain in pediatric orchiopexy and hernia repair

Bupivacaine was utilized for postoperative analgesia in patients undergoing orchiopexy and hernia repair. In a study of 75 pediatric patients, ranging in ages from twelve months to twelve years, who had undergone orchiopexy and hernia repair during a three-year period, 42 received bupivacaine hydrochloride as a local infiltration block anesthesia to relieve postoperative pain; 33 patients did not receive bupivacaine. Patients receiving bupivacaine had less postoperative pain and were more comfortable when leaving the hospital within a few hours after surgery.     

Infraclavicular brachial plexus block: variation in approach and results in 360 cases.

BACKGROUND AND OBJECTIVES: Brachial plexus block is clinically useful. Although the infraclavicular approach to brachial block is the less commonly used form it may offer advantages. We describe the results with three local anesthetic mixtures used during this observational study. METHODS: Three hundred and sixty patients, ASA physical status I and II, scheduled for upper extremity orthopedic surgery, were anesthetized with an infraclavicular brachial plexus block. They were divided into three groups (120 patients each) by type of 40-mL anesthetic mixture: group I had even parts of 2% plain lidocaine and 0.5% bupivacaine with epinephrine 1:200,000; group II had even parts of 1% plain lidocaine and 0.25% bupivacaine with epinephrine 1:200,000; and group III had even parts of 1.5% plain lidocaine and 0.37% bupivacaine with epinephrine 1:200,000. Plexus identification was made by nerve stimulator. The observational assessments were: adequacy and latency time of the block, tourniquet tolerance, postoperative analgesia, local anesthetics doses, sedative doses, complications, and side effects. RESULTS: In groups I, II, and III, adequacy of the block was 95, 75, and 96%, latency time was 10.4, 12.9, and 10.9 minutes, tourniquet tolerance was 99, 84, and 98%, postoperative analgesia time was 663, 331, and 502 minutes, anesthetic doses of lidocaine/bupivacaine were 5.2/1.3, 2.9/0.7 and 4.1/1.1 mg/kg, respectively. Differences were noted between group II and groups I and III (P range: .01-.0001). Sedatives in adequate blocks were midazolam with/without fentanyl (2-3 mg/50-100 microg) in all groups. There were two complication cases with no consequences: two vascular punctures that did not hold up or delay the anesthetic or surgical procedure. There were no clinical manifestations or side effects. CONCLUSIONS: The infraclavicular approach described is effective. It produced reliable anesthesia and is associated with minimal complications and side effects. The mixture of local anesthetics used in group II is not adequate for producing reliable anesthesia.     

Regional anesthesia for hand surgery

Several regional anesthetic techniques for hand and wrist surgery are mentioned. Of these techniques, the axillarybrachial plexus block offers several advantages, such as ease of administration, prolongation of analgesia, and very few potential complications. Three conditions must be met to provide effective regional anesthesia: (1) patient instruction, (2) a surgeon comfortable with the technique, and (3) a prepared anesthesiologist. The axillary brachial plexus block is performed aseptically in a manner that promotes proximal spread of local anesthetic, giving the opportunity to block the musculocutaneous nerve before its exit from the sheath. In our institution, we favor 1.5% mepivacaine versus 0.5 bupivacaine because of its inherent safety factor. However, all local anesthetics have the potential for systemic toxicity with either inadvertent intra-arterial injection or use of excessive amounts of drug. Toxic symptoms range from mild, such as as tinnitus, to more severe, such as convulsions, and further progression to cardiovascular collapse. This toxicity must be anticipated and treated appropriately. Our own institutional study showed an 89% success rate with axillary brachial plexus blocks used for hand and wrist procedures. However, the success rate dropped to 60% for surgery involving the elbow. These results were improved by the use of local anesthetic supplementation or intravenous sedation.     

Intrathecal fentanyl,sufentanil, or placebo combined with hyperbaric mepivacaine 2% for parturients undergoing elective cesarean delivery

Worldwide, long-acting bupivacaine is the most popular local anesthetic for spinal anesthesia in parturients undergoing elective cesarean delivery. With advances in surgical techniques, e.g., the Misgav Ladach method, and shorter duration of surgery, the local anesthetic mepivacaine, with an intermediate duration of action, may be a reasonable alternative. Our aim in the present study was to evaluate the effects of 2% hyperbaric mepivacaine alone, or combined with either intrathecal fentanyl (5 and 10 microg), or sufentanil (2.5 and 5 microg), on sensory, motor, and analgesic block characteristics, hemodynamic variables, and neonatal outcome in a randomized, prospective, and double-blinded study (n = 100, 20 parturients per group, singleton pregnancy, >37 wk of gestation). No parturient experienced intraoperative pain. The average duration of motor block Bromage 3 in all groups was 68 min, and resolution time to Bromage 0 was 118 min. Maximal cephalad sensory block level was T3-6 and could be established within 6 min. Complete analgesia was significantly prolonged in all groups receiving intrathecal opioids, yet, with sufentanil 5 microg, even the duration of effective analgesia was significantly extended. Neonatal outcome was not affected by intrathecal opioid administration. In conclusion, 2% hyperbaric mepivacaine is a feasible local anesthetic for spinal anesthesia in parturients undergoing elective cesarean delivery, particularly with short duration of surgery. IMPLICATIONS: Sensory, motor, and analgesic block characteristics of the local anesthetic mepivacaine alone or combined with intrathecal opioids were studied in parturients undergoing elective cesarean delivery in a randomized, double-blinded clinical trial. Mepivacaine was found to be an acceptable local anesthetic for spinal anesthesia in parturients undergoing cesarean delivery. In combination with sufentanil 5 microg, complete and effective analgesia were significantly prolonged.     

Postoperative pain relief by continuous epidural infusion of bupivacaine and buprenorphine]

Continuous postoperative pain relief produced by epidural block with bupivacaine and buprenorphine was evaluated in 12 patients after thoracotomy, 19 patients after upper abdominal surgery, and 14 patients after lower abdominal surgery. Patients initially received 8 ml of 0.25% bupivacaine and 0.1 mg of buprenorphine at recovery room in operating theater and continuously received the mixture of 0.25% bupivacaine and 5 micrograms.ml-1 buprenorphine at a rate of 1 ml.h-1 using a portable pump. About fifty percent of the patients did not need additional narcotics during 48 postoperative hours. About ninety percent of the patients needed one additional narcotics during 48 postoperative hours. The authors conclude that epidural analgesia with the mixture of bupivacaine and buprenorphine produces satisfactory postoperative pain relief.