Comparison of bupivacaine and alkalinized bupivacaine in brachial plexus anesthesia

To define the effect of alkalinization of bupivacaine 0.5% in subclavian perivascular brachial plexus blockade, the time to onset, time to peak effect, and 6-hour regression of sensory and motor blockade were determined. Sixty physical status ASA I and II patients were randomly allocated to one of two groups and a double-blind design was used: group I (n = 30) received bupivacaine 0.5% (pH, 5.5) 3 mg/kg, while group II (n = 30) received alkalinized bupivacaine 0.5% (pH, 7.05-7.15) 3 mg/kg. Onset and regression of sensory blockade were determined by pinprick in the C4-T2 skin dermatomes, while motor blockade was assessed using a scheme of proximal to distal muscle group paralysis. Time to onset of sensory blockade (group I, 4.0 +/- 1.2 min; group II, 3.6 +/- 0.9 min) and time to peak sensory effect (group I, 17.7 +/- 1.8 min; group II, 16.3 +/- 1.8 min) did not differ significantly between the groups. Similarly, no difference in time to onset of motor blockade (group I, 6.9 +/- 1.7 min; group II, 6.3 +/- 1.5 min) or time to peak motor effect (group I, 18.1 +/- 1.9 min; group II, 15.1 +/- 1.9 min) was observed. Regression of postoperative sensory and motor blockade was similar in both groups. It is concluded that alkalinization of bupivacaine 0.5% solutions does not confer any added clinical advantage in subclavian perivascular brachial plexus blockade when compared with commercially available bupivacaine.     

A comparison between epidural anaesthesia using alkalinized solution and spinal (combined spinal/epidural) anaesthesia for elective caesarean section

In a double-blind investigation, 40 women undergoing elective lower segment caesarean section were randomly divided into two groups. Group I (n = 20) received spinal anaesthesia with 2.0 ml hyperbaric 0.5% bupivacaine using a single space combined spinal epidural technique. Group II (n = 20) received epidural anaesthesia with a local anaesthetic mixture consisting of 0.5% bupivacaine plain 10 ml and 2% lignocaine plain 10 ml to which was added 0.1 ml of adrenaline 1 in 1000 and 2 ml of 8.4% sodium bicarbonate. The mean onset times of sensory block to T4 and grade 3 motor blockade were 7.9 min and 9.5 min respectively in the spinal group, compared to 13.1 min and 16.3 min in the epidural group. These differences were both significant (P < 0.05). There was no difference between the two groups in the quality of analgesia or the incidence of hypotension and nausea. The relatively rapid onset of the pH adjusted epidural solution may provide an attractive alternative to spinal anaesthesia. Moreover, this study underlines the important role of pH adjusted epidural solutions in parturients progressing to emergency caesarean section with epidural catheters previously inserted for labour analgesia.     

A comparison of epidural levobupivacaine 0.5% with or without epinephrine for lumbar spine surgery

Levobupivacaine, the S(-) isomer of bupivacaine, is less cardiotoxic than racemic bupivacaine. In this prospective, randomized, double-blinded study of epidural anesthesia, we compared the onset, extent, and duration of sensory and motor blockade produced by plain 0.5% levobupivacaine (15 mL, 75 mg) with that of 0.5% levobupivacaine with the addition of 1:400,000 or 1:200,000 epinephrine in 117 patients undergoing elective spine surgery. The time to onset of adequate sensory block (T10 dermatome) was similar in all groups (12.4 +/- 6.6 min for plain levobupivacaine, 13.9 +/- 7.9 min for levobupivacaine with 1:400,000 epinephrine, and 12.7 +/- 4.9 min for levobupivacaine with 1:200,000 epinephrine), with an average peak block height of T5. Time to complete regression of sensory blockade was also similar between groups (357 +/- 119 min for plain levobupivacaine, 378 +/- 98 min for levobupivacaine with 1:400,000 epinephrine, and 348 +/- 80 min for levobupivacaine with 1:200,000 epinephrine). Peak serum levobupivacaine levels were reduced in each of the epinephrine-containing groups. We conclude that 0.5% levobupivacaine with or without 1:200,000 or 1:400,000 epinephrine produced effective epidural anesthesia in patients having lumbar spine surgery. Epinephrine 1:400,000 is as effective as 1:200,000 in reducing the resultant serum levobupivacaine levels after epidural anesthesia.     

Intraoperative epidural anesthesia and postoperative analgesia with levobupivacaine for major orthopedic surgery: a double-blind,randomized comparison of racemic bupivacaine and ropivacaine

STUDY OBJECTIVE: To compare the onset time and duration of epidural anesthesia, and the quality of postoperative analgesia produced by levobupivacaine, racemic bupivacaine, and ropivacaine. DESIGN: Prospective, randomized, double-blinded study. SETTING: Inpatient anesthesia at a University Hospital. PATIENTS: 45 ASA physical status I, II, and III patients, undergoing elective total hip replacement. INTERVENTIONS: After standard intravenous midazolam premedication and infusion of 500 mL of Ringer's acetate solution, patients were randomly allocated to receive epidural block with 0.5% levobupivacaine (n = 15), 0.5% bupivacaine (n = 15), or 0.5% ropivacaine (n = 15). Postoperatively, after pinprick sensation recovered at T(t), a patient-controlled epidural infusion was provided with 0.125% levobupivacaine, 0.125% bupivacaine, or 0.2% ropivacaine, respectively (baseline infusion rate 5 mL/hr; incremental bolus 2 mL, lockout time: 20 min). Intravenous ketoprofen was also available for rescue analgesia if required. MEASUREMENTS AND MAIN RESULTS: The onset time of sensory block was 31 +/- 16 minutes with levobupivacaine, 25 +/- 19 minutes with bupivacaine, and 30 +/- 24 minutes with ropivacaine (p = 0.98), after a median (range) volume of 15 (10-18) mL in Group Levobupivacaine, 14 (10-18) mL in Group Bupivacaine, and 15 (10-18) mL in Group Ropivacaine (p = 0.85). Six patients in the ropivacaine group (40%) showed an intraoperative Bromage score <2 as compared with only three patients of Group Levobupivacaine (20%) and no patient of Group Bupivacaine (p = 0.02). Recovery of pinprick sensation at T(t) occurred after 214 +/- 61 minutes with levobupivacaine, 213 +/- 53 minutes with bupivacaine, and 233 +/- 34 minutes with ropivacaine (p = 0.26). A similar degree of pain relief was observed in the three groups without differences in local anesthetic consumption and need for rescue analgesia. Motor blockade progressively resolved without differences among the three groups. CONCLUSIONS: Levobupivacaine 0.5% produces an epidural block of similar onset, quality, and duration as the one produced by the same volume of 0.5% bupivacaine, with a motor block deeper than that produced by 0.5% ropivacaine. When prolonging the block for the first 12 hours after surgery with a patient-controlled epidural infusion, 0.125% levobupivacaine provides adequate pain relief after major orthopedic surgery, with similar recovery of motor function as compared with 0.125% bupivacaine and 0.2% ropivacaine.     

The effect of pH adjustment of bupi-vacaine on onset and duration of epidural anaesthesia for Caesarean section

Previous studies have reported that elevation of the pH of local anaesthetics results in more rapid onset of action, with enhanced quality and duration of block. This study investigated the effect of pH adjustment of 0.5 per cent bupivacaine immediately prior to epidural anaesthesia for Caesarean section. Addition of 0.1 ml of 8.4 per cent sodium bicarbonate to 20 ml of 0.5 per cent bupivacaine consistently raised the pH of the local anaesthetic from 5.49 to 7.04 (mean values). One hundred patients, presenting for elective Caesarean section under epidural anaesthesia participated in the study. Forty patients received epidural anaesthesia, using pH-adjusted 0.5 per cent bupivacaine, in a dosage adequate to produce block to the T4 level. A control group of 40 patients received the standard commercial preparation of 0.5 per cent bupivacaine. A further ten patients in each group received epidural anaesthesia using 0.5 per cent bupivacaine with the addition of 1:400,000 epinephrine, to study the effect of epinephrine on pH adjustment of the local anaesthetic. Elevation of the pH of the local anaesthetic significantly increased the speed of onset of action from 6.4 minutes to 3.2 minutes and the time to peak effect from 24.8 minutes to 18.1 minutes, while the duration of anaesthesia was increased from 124.8 minutes to 147.3 minutes. The time to S2 segment blockade was also shortened from 13.5 to 8.6 minutes. Addition of 1:400,000 epinephrine to the local anaesthetic did not influence the effect of pH adjustment. Maternal and umbilical cord plasma levels of bupivacaine were not affected by pH adjustment of the local anaesthetic, while MV/UV and UA/UV ratios were unaltered.     

Fentanyl in 2% mepivacaine compared with fentanyl in 0.5% bupivacaine: two parallel controlled double blind studies

The efficacy of epidural mepivacaine and bupivacaine, combined with fentanyl to enhance blockade, was compared in two parallel controlled, double-blind clinical trials. Patients in the studies (n = 91) were scheduled for orthopedic surgery of the legs and a tourniquet was used in all cases. Those patients receiving mepivacaine attended day surgery only, whereas patients receiving bupivacaine were hospitalised. Epidural puncture was performed with a Tuohy needle at the L3-4 level in the lateral decubitus position. Levels of sensory and motor blockade were assessed; adverse reactions and pain during surgery were recorded. There were four groups of patients: 1) 26 received 2% mepivacaine with placebo; 2) 26 received 2% mepivacaine with 0.1 mg fentanyl; 3) 19 received 0.5% bupivacaine with placebo and 4) 20 patients received 0.5% bupivacaine with 0.1 mg fentanyl. The levels of the sensory blockade was comparable in all groups. The degree of motor-blockade was more intense in the mepivacaine groups, but the blockade by mepivacaine lasted shorter. Addition of fentanyl did not change the sensory and motor blockade. Intraoperative pain was reported by: 7 patients in the mepivacaine/placebo group; 4 patients in the mepivacaine/fentanyl group; 4 patients in the bupivacaine/placebo group; and by one patient in the bupivacaine/fentanyl group. These results indicate that fentanyl enhances the quality of epidural blockade when combined with either mepivacaine or bupivacaine.     

The influence of a bupivacaine and fentanyl epidural infusion after epidural fentanyl in patients allowed to ambulate in early labor

Epidural fentanyl after a lidocaine and epinephrine test dose provides adequate analgesia and allows for ambulation during early labor. This study was designed to determine the influence of an epidural infusion of bupivacaine plus fentanyl administered after initiation of epidural labor analgesia with fentanyl. Specifically, we evaluated whether there is an increase in motor block or an increased time to request for further analgesic medication. Fifty-one laboring primigravid women at <5 cm cervical dilation who requested epidural analgesia were enrolled. After a 3-mL epidural test dose of 1.5% lidocaine with epinephrine (5 microg/mL), patients received fentanyl 100 microg via the epidural catheter. They then randomly received either an infusion (10 mL/h) of 0.0625% bupivacaine with fentanyl (3 microg/mL) or an infusion of preservative-free saline. After the administration of the initial analgesic, pain scores and side effects were recorded for each patient at 10, 20, and 30 min, every 30 min thereafter, and at the time of request for additional analgesic medication, by an observer blinded to the technique used. There were no demographic differences between the two groups. The mean duration of analgesia (time from initial dose to request for additional analgesia) was increased in the group that received a continuous infusion of bupivacaine and fentanyl compared with the Saline group (198 +/- 86 vs 145 +/- 50 min; P < 0.009). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block. Fourteen patients chose to ambulate in the Saline group, and 12 patients chose to ambulate in the Infusion group. In early laboring patients, a continuous infusion of 0.0625% bupivacaine infusion with fentanyl (3 microg/mL) prolonged the duration until top-up was required, after epidural fentanyl 100 microg after a lidocaine and epinephrine test dose, and did not cause any clinically detectable motor block. IMPLICATIONS: A 0.0625% bupivacaine and fentanyl (3 microg/mL) infusion, when added to epidural fentanyl (100 microg), prolongs the analgesic duration without increasing motor block in women in early labor.     

Levobupivacaine versus racemic bupivacaine for spinal anesthesia.

Levobupivacaine is the pure S(-)-enantiomer of racemic bupivacaine but is less toxic to the heart and central nervous system. Although it has recently been introduced for routine obstetric and nonobstetric epidural anesthesia, comparative clinical studies on its intrathecal administration are not available. We therefore performed this prospective randomized double-blinded study to evaluate the anesthetic potencies and hemodynamics of intrathecal levobupivacaine compared with racemic bupivacaine. Eighty patients undergoing elective hip replacement received either 3.5 mL levobupivacaine 0.5% isobaric or 3.5 mL bupivacaine 0.5% isobaric. Sensory blockade was verified with the pinprick test; motor blockade was documented by using a modified Bromage score. Hemodynamic variables (e.g., blood pressure, heart rate, pulse oximetry) were also recorded. Intergroup differences between levobupivacaine and bupivacaine were insignificant both with regard to the onset time and the duration of sensory and motor blockade (11 +/- 6 versus 13 +/- 8 min; 10 +/- 7 versus 9 +/- 7 min; 228 +/- 77 versus 237 +/- 88 min; 280 +/- 84 versus 284 +/- 80 min). Both groups showed slight reductions in heart rate and mean arterial pressure, but there was no intergroup difference in hemodynamics. We conclude that intrathecal levobupivacaine is equal in efficacy to, but less toxic than, racemic bupivacaine. IMPLICATIONS: Levobupivacaine, the pure S(-)-enantiomer of racemic bupivacaine is an equally effective local anesthetic for spinal anesthesia compared with racemic bupivacaine.     

Alkalization of bupivacaine in the combination fentanyl-bupivacaine in epidural obstetrical analgesia

A randomized double blind study was carried out to determine whether alkalization of a 0.25% bupivacaine solution in a fentanyl-bupivacaine mixture hastened the onset, and increased the duration and quality, of extradural analgesia during labour. The study included 120 women with uncomplicated full-term gestation. Prior to the extradural injection, 0.1 ml of either 8.4% sodium bicarbonate or normal saline was randomly added to 20 ml of 0.25% bupivacaine. The patients were given 75 micrograms fentanyl with 12 ml of either alkalized or unaltered bupivacaine. Data for analysis were obtained in 106 parturients (bicarbonate group n = 54; control group n = 52). The pH of alkalized and unaltered bupivacaine were 7.07 +/- 0.01 and 5.56 +/- 0.01 respectively. There were no statistically significant differences between the bicarbonate and control groups with regard to the speed of onset of analgesia (7.08 +/- 0.7 min vs. 6.78 +/- 0.6 min), its duration (123.6 +/- 10.7 min vs. 113 +/- 6.6 min), and the number of cases of inadequate pain relief (6 and 3 respectively). The rate of maternal adverse effects, and neonatal status, were similar in both groups. It can be concluded that alkalizing a 0.25% bupivacaine solution in a fentanyl-bupivacaine mixture for epidural analgesia in labour has no clinical value.     

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%.     

Isobaric and hyperbaric bupivacaine 0.5% solution for spinal anesthesia

The effects of spinal anesthesia with 0.5% isobaric and hyperbaric (8% glucose) bupivacaine were investigated in 45 patients who had lower limb or lower abdominal surgery. The patients were divided into 3 groups. Group 1 patients received 3 ml of 0.5% isobaric bupivacaine. The patients in group 2 and 3 received 3 or 2 ml of 0.5% hyperbaric bupivacaine (8% glucose). Blood pressure dropped in all groups. The decrease in blood pressure was so severe in group 2 that vasopressors were required in 70% of cases. The average segmental level of analgesia was T9 in group 1, C8 in group 2 and T4 in group 3. Complete motor blockade was obtained in all the patients. Time to complete motor blockade of the lower limbs was 12.6 min in group 1, 5.5 min in group 2 and 8.4 min in group 3. Duration of analgesia and motor blockade were 387.4 min and 303.7 min in group 1, 373.5 min and 300.0 min in group 2 and 318.9 min and 228.9 min in group 3. These results suggest that adequate surgical anaesthesia could be obtained with 3 ml of 0.5% isobaric bupivacaine and 2 ml of 0.5% hyperbaric bupivacaine.     

A double-blind comparison of 0.125% ropivacaine with sufentanil and 0.125% bupivacaine with sufentanil for epidural labor analgesia

BACKGROUND: This study intends to evaluate the benefits of the administration of intermittent bolus doses of ropivacaine (0.125%) compared with bupivacaine (0.125%) after addition of sufentanil for analgesia during labor. METHODS: One hundred thirty American Society of Anesthesiologists physical status 1 or 2 parturients were studied. The 90 initial patients were assigned randomly to receive 10 ml bupivacaine, 0.125%, plus 7.5 microg sufentanil (initial bupivacaine 0.125% group) or ropivacaine, 0.125%, plus 7.5 microg sufentanil (ropivacaine 0.125% group). Forty additional patients were recruited and received 0.125% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.125% group) or 0.100% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.100% group). The duration of analgesia, visual analogue scores for pain, motor blockade (using a six-point modified Bromage scale), patient satisfaction scores, nausea, pruritus, heart rate, and blood pressure were recorded. RESULTS: Bupivacaine 0.125% and ropivacaine 0.125% coadministered with sufentanil provided rapid and complete analgesia. Onset of analgesia occurred after +/-15 min and lasted +/-90 min. After the third epidural injection, patients in the ropivacaine group experienced significantly less severe motor blockade than patients in the initial bupivacaine 0.125% group. At this point, 93% of the patients in the ropivacaine group were free from motor impairment versus 66% in the bupivacaine group (P<0.05). Comparable levels of motor blockade were obtained in both additional groups. Patients' evaluation of their analgesia was worst in the bupivacaine 0.100% group. CONCLUSIONS: Ropivacaine 0.125% with sufentanil affords reliable analgesia with minimal motor blockade.     

A new local anesthetic, ropivacaine. Its epidural effects in humans

The current study was initiated to evaluate the epidural anesthetic properties of 0.5%, 0.75%, and 1.0% ropivacaine, a new local anesthetic agent structurally similar to bupivacaine. Fifteen patients scheduled for lower limb orthopedic surgery were enrolled in the study. As the concentration of ropivacaine increased from 0.5% to 1.0%, the time to onset of sensory anesthesia decreased from 6.4 +/- 1.7 (SD) min to 2.4 +/- 0.6 min and the maximum level of sensory anesthesia increased from T6 to T1. These changes were not statistically significant. Time to regression of anesthesia to T12 increased from 255 +/- 73 min with the 0.5% solution to 356 +/- 75 min with 1.0% ropivacaine (P less than 0.05). The degree of motor blockade using the Bromage scale varied with the concentration. When the 0.5% concentration was used, only one patient (20%) had greater than 1+ motor blockade. However, all of the patients receiving the 0.75% or 1.0% solution had at least 2+ motor blockade. Sensory anesthesia was adequate for surgery in 14 of the 15 patients. The mean peak plasma concentration of ropivacaine (Cmax) increased from 0.65 +/- 0.15 micrograms/mL with the 100-mg dose to 1.30 +/- 0.43 microgram/mL with the 200-mg dose. No adverse effects were noted in any patient in the study. These initial studies in humans suggest that ropivacaine provides satisfactory sensory anesthesia with minimal motor blockade at a concentration of 0.5%. An increase in concentration resulted in a more profound motor blockade. The Cmax of ropivacaine in this study was below levels associated with toxicity in animal studies.     

Anesthésie péridurale pour la chirurgie de la cheville et du pied: influence de la position assise

The effects of the sitting position on the quality of both sensory and motor blockade of segments L5 and S1 and the haemodynamic consequences during epidural anaesthesia were studied on 39 patients undergoing ankle or foot surgery. After insertion of an epidural catheter with the patient in the lateral position, 19 patients were kept sitting for 15 min following the injection of the local anaesthetic and 20 remained supine for the duration of anaesthesia (control group). All patients received a dose of 20 ml of 1.73% carbonated lidocaine with epinephrine 1:200,000. The quality and time of onset of the sensory blockade for segments L1-S2 as well as its cephalad spread were comparable in both groups. Fourteen patients of the sitting group achieved motor blockade of more than three of five myotomes compared with five patients in the supine group (P less than 0.001). The maximum decrease in mean arterial pressure occurred sooner in the sitting group (14 +/- 9 min) than in the control group (21 +/- 10 min; P less than 0.01) and was more severe (-24 +/- 10% vs -16 +/- 10% respectively; P less than 0.05). Our results indicate that placing the patient in the sitting position for 15 min after inducing epidural anaesthesia does not influence caudal sensory blockade but does increase the depth of motor blockade.     

Onset of spinal block is more rapid with isobaric than hyperbaric bupivacaine

PURPOSE: To compare isobaric with hyperbaric 9.75 mg bupivacaine injected intrathecally, and to evaluate the effects of subsequent injection of lidocaine 2% into the epidural space. METHODS: Patients in group 1 (n = 30) received isobaric 9.75 mg bupivacaine and in group 2 (n = 30) hyperbaric 9.75 mg bupivacaine injected into the subarachnoid space in a combined spinal-epidural technique. They were undergoing urological, gynecological, orthopedic, gastro-intestinal or vascular surgery. Using a double blind technique, the followings parameters were measured: cutaneous analgesia to pinprick, motor blockade, time for two segment regression, time for complete regression of the motor block, quality of anesthesia. In 12 patients the effect of epidural injections of 3 ml lidocaine 2% was observed. RESULTS: Motor and sensory block developed more rapidly (five minutes) in the isobaric group (P<0.05). Maximum upper level (T7+/-2), two-segment regression (52 min in both groups), motor recovery (160 vs. 157 min), and quality of anesthesia did not differ between the two groups. Thirty nine epidural injections of 3 ml lidocaine 2% were given in 12 patients 10 min after spinal injection, 28 were in the hyperbaric group (P<0.05). Twenty six of the epidural injections produced an increase in sensory block of 0 or 1 dermatome, and 13, of 2 or more. CONCLUSION: The block developed more rapidly in the isobaric group, but both isobaric and hyperbaric 9.75 mg bupivacaine produced adequate upper levels of analgesia for surgery. The effect of epidural injections of 3 ml lidocaine 2% was usually minimal.     

Does the addition of tris(hydroxymethyl) aminomethane to 0.5% bupivacaine delay epidural onset in parturients?

A rapid onset of epidural anesthesia may predispose a pregnant patient to hypotension during the first stage of labor. Sodium bicarbonate has been reported to hasten epidural onset of chloroprocaine, lidocaine and bupivacaine while tris(hydroxymethyl) aminomethane (THAM) has been shown to delay the onset of epidurally administered chloroprocaine in parturients. The purpose of this study was to determine whether the addition of THAM to bupivacaine affected the onset, cephalad spread and incidence of hypotension following epidural administration in healthy pregnant patients during the first stage of labor. Three groups each consisting of 20 ASA I or II patients were studied. Group I received 0.5% bupivacaine with saline (0.06 ml/10 ml). Group II received bupivacaine buffered with THAM (0.06 ml/10 ml) to a pH of 6.8. Group III received bupivacaine buffered to a pH of 6.8 with sodium bicarbonate (0.05 ml+0.01 ml saline/10 ml). Statistical analysis used one-way analysis of variance and the appropriate post hoc test for multiple comparisons. A [Formula: see text] value less than 0.05 was considered significant. The onset of analgesia, the cephalad spread, and the incidence of hypotension did not differ between the groups. It is concluded that THAM does not affect the pharmacodynamics of 0.5% bupivacaine administered epidurally.     

Levobupivacaine combined with sufentanil and epinephrine for intrathecal labor analgesia: a comparison with racemic bupivacaine

We performed a randomized, double-blinded study to compare levobupivacaine with racemic bupivacaine for labor analgesia. Eighty term parturients received either levobupivacaine 0.125% or racemic bupivacaine 0.125%, to which was added sufentanil 0.75 microg/mL and epinephrine 1.25 microg/mL. As part of a combined spinal-epidural procedure, 2 mL of this mixture was initially injected intrathecally, and the same solutions were subsequently administered epidurally. For both combinations, onset until the first painless contraction was 4 to 5 min. Most patients were pain free during the second contraction. The duration of initial spinal analgesia was 93.5 +/- 20 min and 94.7 +/- 31 min for levobupivacaine and racemic bupivacaine, respectively. The duration of analgesia for the first epidural top-up dose was also similar in the two groups. Total local anesthetic requirements during labor were not different. The only major difference observed was the absence of motor impairment in levobupivacaine-treated parturients as compared with the Racemic Bupivacaine group, in which the incidence of a Bromage-1 motor block was 34%. Other side effects and obstetric or neonatal outcomes were not different between groups. Intrathecal levobupivacaine has a similar clinical profile as racemic bupivacaine, but at equal doses it produced less motor block. IMPLICATIONS: When used intrathecally and epidurally for labor analgesia, levobupivacaine had the same clinical profile as racemic bupivacaine, but at equal doses it produced less motor block.     

Skin pulse wave monitoring during lumbar epidural and spinal anesthesia

The effectiveness of pulse wave monitoring of the big toes was compared with loss of cold discrimination to determine the onset of nerve blockade during lumbar epidural and spinal anesthesia. Forty-seven patients scheduled for elective urologic or lower extremity operations were assigned to one of three groups. Group 1 (15 patients) received epidural mepivacaine 1.5% with epinephrine; group 2 (12 patients), epidural bupivacaine 0.5%, and group 3 (20 patients), spinal bupivacaine 0.5%. In the epidural groups, the mean time to onset of increases in pulse wave amplitude was less than half the mean time to onset of decrease in cold discrimination (P less than 0.05). In patients given spinal anesthesia, there was no significant difference. The pulse wave monitor seems to be a sensitive and objective detector of early anesthetic effect during spinal and epidural anesthesia.     

Reversal of lidocaine with epinephrine epidural anesthesia using epidural saline washout

BACKGROUND AND OBJECTIVES: Prolonged motor and sensory block following epidural anesthesia can be associated with extended postoperative care unit stays and patient dissatisfaction. Previous studies have demonstrated a more rapid motor recovery following the administration of epidural crystalloids in patients who had received plain bupivacaine and lidocaine epidural anesthesia. However, epinephrine is commonly added to local anesthetics to improve the quality and prolong the duration of the epidural block. The objective of this study was to determine the relationship of 0.9% NaCl epidural catheter flush volume (i.e., washout) to the recovery of motor and sensory block in patients undergoing 2% lidocaine with epinephrine epidural anesthesia. METHODS: A prospective, randomized, double-blind study design was utilized. Thirty-three subjects scheduled for elective gynecologic or obstetrical surgical procedures underwent epidural anesthesia using 2% lidocaine with epinephrine (1:200,000). A T4 dermatome level of analgesia, determined by toothpick prick, was maintained intraoperatively. Following surgery, subjects were randomized to 1 of 3 treatment groups. Group 1 (control, n = 11) received no epidural 0.9% NaCl (normal saline [NS]) postoperatively. Group 2 (15 mL NS x 1, n = 10) received an epidural bolus of 15 mL NS. Group 3 (15 mL NS x 2, n = 12) received an epidural bolus of 15 mL NS postoperatively and a second 15-mL NS bolus 15 minutes later. Assessment of motor and sensory block was performed at 15-minute intervals until complete motor and sensory recovery. RESULTS: Times to partial and full motor and sensory recovery were significantly faster in the epidural NS groups than in the control group. Full motor recovery was more rapid in subjects receiving two 15-mL NS epidural NS boluses (30 mL total) compared with those receiving a single 15-mL NS bolus (108 +/- 9 min v 136 +/- 13 min) and significantly faster than control group subjects (153 +/- 14 min). Both NS x 1 and NS x 2 epidural bolus groups experienced significantly reduced times to complete sensory recovery when compared with the control group (NS x 1 = 154 +/- 13 min, NS x 2 = 153 +/- 9 min, control 195 +/- 14 min). CONCLUSIONS: A more rapid recovery of motor and sensory block in patients undergoing 2% lidocaine with epinephrine epidural anesthesia can be achieved with the use of 30 mL NS epidural washout. Reg Anesth Pain Med 2001;26:246-251.     

Continuous interpleural infusion of bupivacaine for postoperative analgesia after surgery with flank incisions: a double-blind comparison of 0.25% and 0.5% solutions.

Postoperative analgesia, as assessed by visual analogue scale scores (0-10) and patient-controlled analgesia morphine requirements, pulmonary function (forced vital capacity and forced expiratory volume in 1 s), and plasma bupivacaine concentrations were studied in patients receiving interpleural blockade with bupivacaine after surgery with a flank incision. Two groups of 10 patients received either 0.5% or 0.25% bupivacaine, both with epinephrine (5 micrograms/mL). Pain relief was initiated when patients had visual analogue scale scores greater than or equal to 4. Patients received 21 mL of bupivacaine 0.25% or 0.5% in a double-blind fashion. One hour later, a continuous infusion of 5 mL/h of the study solution was started. At the same time, patient-controlled analgesia became accessible to the patients. The onset time of pain relief and the area under the visual analogue scale score-time curves over the first 8 h were similar in both groups. Patient-controlled analgesia morphine use was also similar in the 0.25% (21.3 +/- 14.6 mg) and 0.5% (21.0 +/- 16.0 mg) groups (mean +/- SD). In both groups, forced vital capacity and forced expiratory volume in 1 s improved significantly within 60 min (P less than 0.05). Peak plasma concentrations (Cmax) and the area under the plasma concentration-time curve (AUC) over 24 h were higher (P less than 0.001) in the 0.5% group (Cmax, 1.47 +/- 0.37 micrograms/mL; AUC, 1511 +/- 323 micrograms.mL-1.min) than those in the 0.25% group (Cmax, 0.55 +/- 0.22 micrograms/mL; AUC, 680 +/- 118 micrograms.mL-1.min) (mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)