Ulnar nerve block induced by the new local anesthetic IQB-9302 in healthy volunteers: a comparison with bupivacaine.

We evaluated the duration of sensory anesthesia after blockade of the ulnar nerve of IQB-9302, a new local amide anesthetic, compared with bupivacaine. A double-blinded, randomized, cross-over study in 12 healthy volunteers aged 18 to 35 yr was performed. Three milliliters of 0.25% IQB-9302 was administered in one wrist and bupivacaine in the other. A week later, the blocks were repeated with a concentration of 0.5%. These concentrations were chosen because they seemed to be equipotent in previous studies. The duration of sensory anesthesia was the main variable measured; secondary outcomes were motor block, time to onset, and time to recovery from block. The duration of sensory block was similar for IQB-9302 and bupivacaine at a concentration of 0.25%; median and range: 409 min (0-800 min) for IQB-9302 and 258 min (0-665 min) for bupivacaine (95% confidence interval for the difference from -47 to 545, P = 0.82, Wilcoxon's test). The results with 0.5% were: 525 min (440-735 min) and 690 min (365-1098 min), respectively (P = 0.026). There were no significant differences in the other variables measured. No important adverse reactions were seen. We conclude that IQB-9302 is an effective new local anesthetic for blockade of ulnar nerve at the concentrations tested. IMPLICATIONS: IQB-9302 is a new local anesthetic that has shown a long duration of action and low cardiovascular toxicity in preclinical studies. We report the results of a phase I clinical trial to compare this new drug with bupivacaine for ulnar nerve block.     

Three-in-one nerve block with different concentrations of bupivacaine in total knee arthroplasty: randomized, placebo-controlled, double-blind trial

Pain after total knee arthroplasty may be severe and lead to adverse outcomes. Using 2 concentrations of bupivacaine, we investigated 3-in-1 nerve block's effect on pain control, narcotic use, sedation, and patient satisfaction. One hundred five patients undergoing unilateral total knee arthroplasty were randomized into 3 groups: low-dose or high-dose bupivacaine or placebo. Ninety-nine patients completed the study. Three-in-1 nerve block reduced patient-controlled opioid analgesia usage and improved pain relief in the early postoperative period but had little effect beyond postoperative day 1. There were no significant differences among groups with respect to nausea or sedation. Patients in each group exhibited high overall satisfaction. Low-dose bupivacaine was superior to high-dose bupivacaine for pain relief, narcotic consumption, and patient satisfaction in the early postoperative period.     

Levobupivacaine caudal anesthesia in children: a randomized double-blind comparison with bupivacaine

BACKGROUND: Levobupivacaine is the pure S-enantiomer of bupivacaine. Despite obvious benefits in the event of accidental intravascular injection there has been no studies demonstrating a clinically significant benefit to levobupivacaine over racemic bupivacaine for pediatric regional anesthesia. Given the similar pharmacokinetic profiles of both drugs the studies to date have been underpowered to demonstrate what is likely to be a small difference in clinical effectiveness. Our aim was to determine if there are significant differences in the clinical effectiveness of levobupivacaine compared with racemic bupivacaine for caudal anesthesia in children having lower abdominal surgery. A secondary aim was to determine if there are differences in the incidence of postoperative motor blockade between these agents. METHODS: Three hundred and ten children ranging in age from 1 month to 10.75 years in age having lower abdominal surgery were enrolled. Patients were randomized in a double blind manner to receive a caudal block with either 0.25% bupivacaine (n = 152) or 0.25% levobupivacaine (n = 155) to a total volume of 1 ml x kg(-1). Motor blockade (modified Bromage scale) and postoperative pain or distress (FLACC behavioral scale for postoperative pain) were measured at predetermined time points during the subsequent 120 min. RESULTS: There were no significant adverse effects attributable to levobupivacaine. Success rates were defined as a lack of hemodynamic response to first surgical incision and low postoperative pain scores. At a mean duration of 5 min between block completion and first incision success for 1 ml x kg(-1) of 0.25% bupivacaine was 91% and 94% for 0.25% levobupivacaine. Satisfactory postoperative analgesia was present in 98% of patients after bupivacaine caudal anesthesia and 97.5% for levobupivacaine. At 30 min following caudal anesthesia the incidence of postoperative motor block with racemic bupivacaine was 84% and decreased to 7% at 120 min. For levobupivacaine motor block at 30 min postcaudal was present in 85% and decreased to 11% at 120 min. CONCLUSIONS: Levobupivacaine is an effective agent for caudal anesthesia in children at a recommended dose of 2.5 mg x kg(-1). The rapidity of onset was suitable for establishment of surgical anesthesia and postoperative analgesia was achieved in greater than 97.5% of patients. It appears to be of equivalent potency to racemic bupivacaine in children requiring lower abdominal surgery.     

Spinal ropivacaine or bupivacaine for cesarean delivery: a prospective, randomized, double-blind comparison

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized, double-blinded study was to compare clinical efficacy and safety of ropivacaine and bupivacaine given intrathecally in combination with morphine for cesarean delivery. METHODS: With ethical committee approval and a written informed consent, 60 women scheduled for elective cesarean delivery under spinal anesthesia were randomly allocated to receive spinal anesthesia with either 20 mg ropivacaine plus 0.1 mg morphine (n = 30) or 15 mg bupivacaine plus 0.1 mg morphine (n = 30). Profile of spinal block (onset and recovery times), cardiovascular effects, and quality of postoperative analgesia (patient-controlled morphine) were recorded by a blinded observer. RESULTS: The onset time of motor block was shorter after bupivacaine (8 +/- 2 min) than after ropivacaine (12 +/- 5 minutes) (P <.05), whereas duration of both sensory and motor blocks was longer after bupivacaine (139 +/- 37 minutes and 254 +/- 76 minutes) than after ropivacaine (112 +/- 27 minutes and 211 +/- 48 minutes) (P <.01 and P <.05, respectively). No differences in intraoperative quality of anesthesia and clinical hypotension requiring ephedrine administration were observed between the two groups. Postoperative analgesia was similarly effective in both groups; however median consumption of patient-controlled morphine during the first 24 hours after surgery was higher in patients of group Ropivacaine (5 mg; range, 0 to 18 mg) than in patients of group Bupivacaine (2 mg; range, 0 to 7 mg) (P <.01). CONCLUSION: Spinal anesthesia produced with 20 mg ropivacaine plus 0.1 mg morphine is as effective and safe as that provided by 15 mg bupivacaine plus 0.1 mg morphine, with an earlier recovery of sensory and motor functions after surgery.     

Motor and sensory blockade after epidural injection of mepivacaine, bupivacaine, and etidocaine--a double-blind study

In a double-blind study of epidural anesthesia, 30 young volunteers were given either 2% mepivacaine (400 mg), 0.5% bupivacaine (100 mg), or 1.5% etidocaine (300 mg), all solutions containing epinephrine (1:200,000). The spread of analgesia was equal in the groups, whereas the longest duration was noted in the etidocaine and bupivacaine groups. With use of a method for determining muscle force, motor blockade during anesthesia was recorded quantitatively for hip flexion, knee extension, and plantar flexion of the big toe. Onset of motor blockade was significantly more rapid with etidocaine than with bupivacaine and mepivacaine. All subjects given etidocaine developed complete motor blockade, but with the other local anesthetics 5%-33% of the initial muscle force remained. The least motor blockade was found in the L5-S2 segment (plantar flexion of the big toe). The duration of maximal motor blockade varied between 60 min (mepivacaine) and 360 min (etidocaine). With each of the three local anesthetics, motor function returned simultaneously in the three muscle groups tested. Complete restoration of muscle function occurred significantly later for etidocaine (600 min) than for bupivacaine (360 min) and mepivacaine (180 min). With etidocaine, the motor blockade outlasted the sensory blockade by 150 min. The Bromage scale corresponded to the motor blockade only during the first half of the regression phase. Not until 1-3 h after attainment of Bromage grade 0 was the muscle force of all movements restored (90% of control values).     

Sciatic nerve block with 0.5% levobupivacaine, 0.75% levobupivacaine or 0.75% ropivacaine: a double-blind, randomized comparison

BACKGROUND AND OBJECTIVE: This prospective, randomized, double-blind study was conducted to evaluate the onset time and duration of sciatic nerve block produced with 0.5% levobupivacaine, 0.75% levobupivacaine and 0.75% ropivacaine. METHODS: Forty-five healthy patients undergoing hallux valgus repair were randomly allocated to receive sciatic nerve block with levobupivacaine 0.5% (n=15), levobupivacaine 0.75% (n=15) or ropivacaine 0.75% 20 mL (n=15). A femoral nerve block was also performed with mepivacaine 2% 15 mL to cover pain related to the thigh tourniquet. A blinded observer recorded the onset time and duration of sciatic nerve block. RESULTS: The median (range) onset time was 5 (5-40) min with 0.75% levobupivacaine, 30 (5-60) min with 0.5% levobupivacaine and 20 (5-50) min with 0.75% ropivacaine (P = 0.02 and P = 0.12, respectively). Mean (25-75 percentiles) first request for pain medication occurred after 13 (11-14) h with 0.75% ropivacaine, 18 (15-19) h with 0.75% levobupivacaine and 16 (13-20) h with 0.5% levobupivacaine (P = 0.002 and P = 0.002, respectively). Rescue tramadol after surgery was required by three patients in the 0.75% levobupivacaine group, eight patients in the 0.5% levobupivacaine group and nine patients in the 0.75% ropivacaine group (P = 0.05). CONCLUSIONS: We conclude that 0.75% levobupivacaine provides a shorter onset time than 0.5% levobupivacaine and a longer duration of postoperative analgesia than both 0.5% levobupivacaine and 0.75% ropivacaine with reduced need for rescue analgesia after surgery.     

Interpleural administration of bupivacaine after cholecystectomy: a comparison with intercostal nerve block

Pethidine requirements and verbal pain scores were recorded in 36 patients after cholecystectomy via subcostal incision. All patients also received 20 ml 0.5% bupivacaine with adrenaline 1/200,000. Group 1 (12 patients) received unilateral intercostal nerve blocks. Interpleural catheters were inserted through the 8th intercostal space in the remaining patients; 12 received local anaesthetic via the catheter immediately after surgery (Group 2) and 12 were given local anaesthetic at three hours (Group 3). Small asymptomatic pneumothoraces were noted on chest X-ray in six of the 24 patients with interpleural catheters. Both types of local anaesthesia produced lower pain scores than pethidine alone (P less than 0.05) with 25% of intercostal nerve blocks and 63% of interpleural catheters requiring no pethidine in the following three hours. The provision of catheter 'top-ups' between six and 18 hours after surgery also resulted in lower pain scores and a reduction in pethidine requirements (P less than 0.05).     

Clonidine as adjuvant for mepivacaine, ropivacaine and bupivacaine in axillary, perivascular brachial plexus block

PURPOSE: To evaluate the effects of clonidine on three local anesthetics (mepivacaine 1%, ropivacaine 0.75% and bupivacaine 0.5%) with comparable potency and almost the same concentration-response relationship. METHODS: One hundred and twenty trauma-patients were randomly allocated into six groups. In the control-groups (Mo/Ro/Bo) brachial plexus was performed using 40 mL of local anesthetic plus 1 mL of NaCL 0.9%. In the clonidine-groups (Mc/Rc/Bc) brachial plexus was performed using each 40 mL of drug plus 1 mL (0.150 mg) of clonidine. Onset-time and the duration of the sensory block were recorded. Data are expressed as mean +/- SD. RESULTS: According to the average sensory block determined by a visual analog scale in the median, ulnar and radial nerve distributions and ranging from 100 (no sensory blockade) to 0 (complete sensory blockade), both mepi-groups showed a rapid onset (at 10 min: -Mo 20 +/- 15/Mc 19 +/- 14; at 30 min: -Mo 3 +/- 4/Mc 5 +/- 4). The ropi-and bupi- groups both had a longer onset time (at 10 min: -Ro 23 +/- 19/Rc 25 +/- 22/Bo 24 +/- 15; at 30 min -Ro 10 +/- 6/ Rc 11 +/- 6 /Bo 12 +/- 4). The onset time in group-Bc was significantly prolonged (at 10 min: -45 +/- 21; at 30 min: -20 +/- 6). Duration of motor blockade was prolonged by clonidine only in the mepivacaine and bupivacaine groups; (in minutes: Mo 212 +/- 47 -Mc 468 +/- 62; Ro 702 +/- 52 -Rc 712 +/- 82; Bo 728 +/- 36 -Bc 972 +/- 72). CONCLUSION: The present study shows that the addition of clonidine has a different impact on each of the three local anesthetics investigated in terms of onset and duration of block.     

The median local analgesic dose of intrathecal bupivacaine with hydromorphone for labour: a double-blind randomized controlled trial

Purpose

Neuraxial hydromorphone has been reported to provide rapid onset of labour analgesia, effective segmental pain relief, and a longer duration of action than commonly used lipophilic opioids. This study was conducted to test the hypothesis that intrathecal hydromorphone reduces the dose requirement for intrathecal bupivacaine to induce rapid analgesia for women in the first stage of labour.

Methods

In this double-blind randomized controlled sequential allocation trial, 88 labouring parturients received combined spinal-epidural analgesia at 2-6 cm cervical dilation. Participants received intrathecal bupivacaine alone or bupivacaine plus hydromorphone 100 μg with the bupivacaine dose determined using up-down sequential allocation. An effective dose was defined as a visual analogue pain score of ≤10 mm (on a 100-mm pain scale) reported within 20 min of injection. The median effective doses were calculated using the formula of Dixon and Massey and verified using isotonic regression.

Results

A decrease was observed in the median local analgesic doses (effective dose [ED50]) estimated according to the formulas of Dixon and Massey, with a between-group difference of ?0.45 mg. The precision of the estimate was wide-ranging (95% confidence interval ?1.23 to 0.33), so no definitive conclusion can be drawn.

Conclusion

Further research is needed to determine whether or not intrathecal hydromorphone 100 μg changes the dose of intrathecal bupivacaine required to induce labour analgesia within 20 min.

Trial registration

The trial was conducted in 2007 prior to widespread acceptance of the standard for clinical trial registration.     

Lumbar plexus and sciatic nerve block for knee arthroplasty: comparison of ropivacaine and bupivacaine

PURPOSE: Information about the onset time and duration of action of ropivacaine during a combined lumbar plexus and sciatic nerve block is not available. This study compares bupivacaine and ropivacaine to determine the optimal long-acting local anaesthetic for lumbar plexus and sciatic nerve block in patients undergoing total knee arthroplasty. METHODS: Forty adult patients scheduled for unilateral total knee arthroplasty, under lumbar plexus and sciatic block were entered into this double-blind randomized study. Patients were assigned (20 per group) to receive lumbar plexus block using 30 ml of local anaesthetic and a sciatic nerve block using 15 ml of local anaesthetic with either bupivacaine 0.5% or ropivacaine 0.5%. All solutions contained fresh epinephrine in a 1:400,000 concentration. Every one minute after local anaesthetic injection, patients were assessed to determine loss of motor function and loss of pinprick sensation in the L1-S1 dermatomes. The time to request first analgesic was documented from the PCA pump. This time was used as evidence of block regression. RESULTS: Blocks failed in four patients in each group. The mean onset time of both motor and sensory blockade was between 14 and 18 min in both groups. Duration of sensory blockade was longer in the bupivacaine group, 17 +/- 3 hr, than in the ropivacaine group, 13 +/- 2 hr (P < 0.0001). CONCLUSION: We conclude that bupivacaine 0.5% and ropivacaine 0.5% have a similar onset of motor and sensory blockade when used for lumbar plexus and sciatic nerve block. Analgesic duration from bupivacaine 0.5% was prolonged by four hours compared with an equal volume of ropivacaine 0.5%.