Subarachnoid bupivacaine 0.5% for caesarean section

A series of 52 patients in whom 0.5% bupivacaine was used to produce spinal analgesia for awake Caesarean section is described. Analgesia tended to be asymmetrical and of limited extent until the patients were turned from the left lateral to the right lateral position immediately after injecting the spinal solution. This movement produced a more symmetrical block with better cephalic spread. Initially 26-gauge spinal needles were passed through a Sise introducer, but this was modified to a needle through needle technique whereby a long-shafted 26-gauge needle was passed through a Tuohy needle which was subsequently used to insert an extradural catheter. The optimal volume of bupivacaine was 2.25-2.75 ml. The mean +/- SEM time to achieve maximal spread of analgesia was 17.5 +/- 0.6 min. The mean- +/- SEM time to the administration of the first postoperative analgesic was 163.5 +/- 7.0 min. The disadvantages of the technique were hypotension and the unpredictable spread of analgesia.     

Subarachnoid versus epidural bupivacaine 0.5% for caesarean section

In order to compare subarachnoid (spinal) and epidural block for caesarean section, 40 women were randomly allocated to spinal or epidural analgesia with bupivacaine. The median dose of bupivacaine was 13 mg in the spinal group versus 155 mg in the epidural group. The mean time from induction to delivery was 32 min shorter in the spinal group (P less than 0.001). In the spinal group one woman was excluded because of spontaneous labour. Three patients in the spinal and one in the epidural group failed to develop adequate analgesia to initiate surgery. For the remaining patients both techniques provided good analgesia during operation. Postoperatively, epidural block provided better pain relief. The patients in the epidural group had a lower pain score during the first 4 h after the operation (P less than 0.01). In spite of similar haemodynamic changes in the two groups, the mean base deficit in umbilical cord blood at delivery was higher in the spinal group (P less than 0.05).     

A comparison of epidural ropivacaine 0.75% and bupivacaine 0.5% with fentanyl for elective caesarean section

BACKGROUND: Early studies suggested that ropivacaine had clinical advantages over bupivacaine with respect to cardiotoxicity and motor block, and that it was suitable for epidural caesarean section. This study was set up to compare epidural 0.75% ropivacaine with a popular bupivacaine/fentanyl mixture for elective caesarean section. METHODS: Eighty women having elective caesarean section under epidural anaesthesia were randomly allocated to receive 20 mL of either 0.75% ropivacaine or 0.5% bupivacaine plus fentanyl 100 microg. Supplementation with 2% plain lidocaine was used where necessary. Times were recorded for onset of sensory block, density and duration of motor block, and the need for supplementation. RESULTS: There was no difference between the groups in the time (mean [SD]) to achieve sensory blockade to cold to T4 (ropivacaine 15.8 [5.6] min, bupivacaine/fentanyl 18.7 [9.1] min, P=0.13) or to S1 (ropivacaine 18.3 [4.6] min, bupivacaine/fentanyl 17.4 [7.6] min, P=0.59), or in the need for supplementation. However, ropivacaine produced a motor block that was denser (median Bromage score ropivacaine 3, bupivacaine/fentanyl 1.5, P=0.0041), and of longer duration (ropivacaine 237 [84] min, bupivacaine/fentanyl 144 [76] min, P<0.0001). CONCLUSIONS: This study suggests that epidural 0.75% ropivacaine without opioid may be used as an alternative to bupivacaine 0.5% with fentanyl for elective caesarean section, but it does not induce anaesthesia any faster and may result in a denser, more prolonged, motor block.     

A comparison of epidural levobupivacaine 0.75% with racemic bupivacaine for lower abdominal surgery

Levobupivacaine, the S(-) isomer of bupivacaine, is less cardiotoxic than racemic bupivacaine. In this prospective, randomized, double-blinded study of epidural anesthesia, the onset, extent, and duration of sensory and motor block produced by 0.75% levobupivacaine (20 mL, 150 mg) was compared with that of 0.75% racemic bupivacaine in 56 patients undergoing elective lower abdominal surgery. The time to onset of adequate sensory block (T10 dermatome) was similar in both treatment groups (13.6 +/- 5.6 min for levobupivacaine and 14.0 +/- 9.9 min for bupivacaine), with an average peak block height of T5 reached at 24.3 +/- 9.4 and 26.5 +/- 13.2 min, respectively. Time to complete regression of sensory block was significantly longer with levobupivacaine (550.6 +/- 87.6 min) than bupivacaine (505.9 +/- 71.1 min) (P = 0.016). Abdominal muscle relaxation was adequate for the scheduled procedure in all patients, and there were no significant differences between the groups in rectus abdominis muscle scores (P = 0.386) and quality of muscle relaxation as determined by the surgeon and anesthesiologist (P = 0. 505 and 0.074, respectively). In conclusion, both 0.75% levobupivacaine and 0.75% bupivacaine produced effective epidural anesthesia and their effects were clinically indistinguishable. Implications: The results of this study indicate that the sensory and motor block produced by 0.75% levobupivacaine is equivalent to that of 0.75% racemic bupivacaine. Both local anesthetics are well tolerated and effective in producing epidural anesthesia for patients undergoing lower abdominal surgery.     

Low-dose 0.25% spinal levobupivacaine with epidural extension for cesarean section: comparison with 0.5% hyperbaric bupivacaine

INTRODUCTION: When low doses of local anesthetic are used in combined spinal-epidural anesthesia for cesarean section, an epidural catheter can be used to enhance a possibly incomplete block or insufficient dose. OBJECTIVE: To compare the efficacy of spinal 0.5% hyperbaric bupivacaine with fentanyl (20 microg) at a conventional high dose of 0.07 mg cm(-1) (group 1) vs 0.25% levobupivacaine at a low dose of 7.6 mg with fentanyl (20 microg) and epidural volume extension with 6 mL of saline through an epidural catheter (group 2). MATERIAL AND METHODS: A randomized clinical trial enrolling patients scheduled for elective cesarean section. RESULTS: Sixty-two patients were studied (31 in each group). Characteristics in the groups were comparable at baseline and the maximum level of sensory block achieved was sufficient for all but 1 patient in group 2 who required general anesthesia. The bupivacaine dose in group 1 ranged from 10.5 to 12 mg. The motor block and duration was less intense in group 2 (P<0.0001) and patients in that group could be transferred out of the postanesthetic care unit earlier. CONCLUSIONS: The use of low doses of levobupivacaine with an opiate in combination with volume extension through an epidural catheter in the context of combined spinal-epidural anesthesia is a safe, effective technique that may allow the doses and motor block to be reduced when hyperbaric levobupivacaine is administered, without adverse events for patients.     

Epidural anesthesia with plain bupivacaine 0.75% for elective caesarean section

The clinical effects of epidural anesthesia with bupivacaine 0.75% for elective caesarean section were investigated in 20 healthy pregnant women. The mean total dose of bupivacaine which offers sufficient sensory and motor block, provided the epidural catheter is properly placed, was 137.5 mg. Maternal hypotension occurred in 4 patients in spite of prehydratation and left uterine displacement. No maternal systemic toxicity or local neurotoxicity was found. The results of the Apgar scoring and the neonatal acid-base studies showed that there is no clinically important neonatal depression with this technique.     

Epidural anaesthesia for caesarean section: a comparison of 0.5% bupivacaine and 2% lignocaine both with adrenaline

Thirty-eight women having caesarean section under epidural anaesthesia received either lignocaine 2% or bupivacaine 0.5% both with adrenaline 1:200,000 in a double-blind, randomised study. The time to establish satisfactory surgical anaesthesia, the volume required and the quality of analgesia as assessed by the anaesthetist, patient pain and discomfort scales and patient approval, were not significantly different. Motor block assessed by the Bromage and RAM-test was greater in the lignocaine group but surgical opinion of abdominal wall relaxation was not significantly different between groups. The bupivacaine group had significantly longer durations of sensory and motor block while the lignocaine group had a higher incidence of maternal shivering, other complication rates being similar. Neonatal outcomes were uniformly good. Both local anaesthetics provided satisfactory epidural anaesthesia and neither proved to have a distinct advantage in the clinical setting of this study.     

Neonatal effects of adding epidural fentanyl to 0.5% bupivacaine for caesarean section

Epidural injection of opioids has been introduced to improve analgesia during labour and caesarean section. This study was designed to quantify placental transfer of fentanyl and to evaluate neonatal effects of adding fentanyl to 0.5% bupivacaine for epidural anaesthesia in women undergoing elective caesarean section at term. The parturients were randomly allocated to one of four groups of 20, who received either saline (control) or 50, 75 or 100 microg of fentanyl added to 20 ml of 0.5% bupivacaine. Apgar scores, time to sustained respiration and umbilical acid-base values did not differ among the groups. The median (interquartile range) umbilical artery to maternal vein fentanyl concentration ratio was 0.34 (0.26-0.48) when the fentanyl groups were taken together. Neurologic and adaptive capacity scores were evaluated at 2 and 24 h. Neonates whose mothers received fentanyl had lower scores with regard to supporting reaction at 2 h and active tone at 24 h, when compared to controls (P<0.05), but there were no differences among the groups with regard to the other test criteria in the neurobehavioural test. In conclusion, epidural injection of fentanyl 50-100 microg did not produce depression of the term neonate.     

Maternal effects of adding epidural fentanyl to 0.5% bupivacaine for caesarean section

Epidural injection of fentanyl added to 0.5% bupivacaine improves epidural anaesthesia during caesarean section. The present prospective randomized double-blind study sought to determine the lowest effective dose of fentanyl. Eighty healthy women at term were divided into four groups of 20, with each group receiving a different 2 ml study solution: saline (control) or 50, 75 or 100 microg of fentanyl added to 20 ml of 0.5% bupivacaine. Additional increments of 0.5% bupivacaine were administered as required at 30 min and onwards until a bilateral block to T4 was attained. The onset, duration and segmental level of analgesia, and degree and duration of motor block were not influenced by the addition of fentanyl. Peroperative quality of analgesia was improved, as the request for supplementary analgesics was less following the addition of 75 or 100 microg of fentanyl (P < 0.05). Postoperatively the time to first supplemental opioid request was prolonged and pain was reduced for at least 6 h from induction of anaesthesia when 75 or 100 microg of fentanyl had been added (P < 0.05). Pruritus was the only side-effect (P < 0.05). In conclusion, fentanyl 75 microg was the lowest effective dose for improving quality of analgesia. Onset time was not reduced by the addition of fentanyl.     

Comparison of 0.75% levobupivacaine with 0.75% racemic bupivacaine for peribulbar anaesthesia

In a single centre, randomised, double-blind study 50 patients scheduled for intra-ocular surgery received 0.75% levobupivacaine or 0.75% racemic bupivacaine for peribulbar anaesthesia. There were no significant differences in the mean (SD) volume of levobupivacaine (11 (2.7) ml) or racemic bupivacaine (10 (2.6) ml) required, time to satisfactory block (levobupivacaine-13 (5.6) min; racemic bupivacaine-11 (4.4) min), peri-operative pain scores or frequency of adverse events between levobupivacaine and racemic bupivacaine. The safer side-effect profile of levobupivacaine may offer significant advantages in the elderly population undergoing cataract extraction in whom intercurrent disease is common.     

Extradural anaesthesia for Caesarean section: a double-blind comparison of 0.5% ropivacaine with 0.5% bupivacaine

Seventy-three parturients for elective Caesarean section wereallocated randomly to receive extradural block with 20 ml ofeither 0.5% ropivacaine or 0.5% bupivacaine. If the block didnot reach T6 within 30 mm, another 5 ml of solution was given.If needed, a further 5 ml was given 45 mm after the main dose.The mean total dose of bupivacaine was 23.1 ml (n = 35) andof ropivacaine 23.7 ml (n = 37). There was no significant differencebetween the groups in the profile of sensory block produced.There was no significant difference in the time of onset, orintensity of motor block between the groups but the durationof motor block was significantly shorter in the ropivacainegroup. There was no significant difference in neonatal outcome,as assessed by Apgar score, umbilical cord bloodgas tensionsat delivery or the neurological and adaptive capacity score2 and 24 h after delivery. (Br. J. Anaesth. 1995; 74: 512–516)     

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.     

A double-blind comparison of epidural bupivacaine and bupivacaine-fentanyl for caesarean section

The effect of adding fentanyl 100 mcg to bupivacaine 0.5% plain to establish epidural anaesthesia for elective caesarean section was investigated in a randomised, double-blind study of sixty healthy women. The quality of intraoperative analgesia as assessed by both patients and anaesthetists was significantly improved with fentanyl. The onset and duration of sensory anaesthesia, degree and duration of motor block, and other characteristics of epidural anaesthesia were unaltered. No adverse maternal side-effects (except mild pruritus) were noted and neonatal outcome was unaffected. The pharmacokinetics of epidural fentanyl administration were investigated by plasma fentanyl assays from maternal and cord blood taken at delivery. Epidural bupivacaine-fentanyl combination is a valuable therapeutic approach to the conduct of epidural anaesthesia for caesarean section in healthy women and foetuses. Further neonatal evaluation of the premature or compromised foetus is suggested before the universal application of this technique.     

Comparison of two fentanyl doses to improve epidural anaesthesia with 0.5% bupivacaine for caesarean section

Ninety women undergoing elective caesarean section under epidural anaesthesia were double blindly randomised into three groups to receive either 2 ml of saline or 50 or 100 μg of fentanyl in 2 ml volume added to 0.5% bupivacaine. Both doses of fentanyl intensified the epidural anaesthesia and reduced patient discomfort during the operation. In both fentanyl groups the epidural blockade more often reached the 5th thoracic segment (P = 0.0258), the patients had significantly less pain (P = 0.0256), needed less intravenous diazepam medication during the operation (P = 0.0005) and the operating conditions were better when compared to the saline group (P = 0.0416). There was no difference between the groups in the condition of the neonates as assessed by the Apgar score and cord blood pH. The postoperative time until treatment for pain was requested by the patients was more than 1 h longer in the fentanyl groups, but there was no difference in the total amount of postoperative analgesics needed during the first 24 h when compared to the saline group. Mild pruritus not requiring treatment was more common in fentanyl groups than in the saline group (P = 0.0187). The results suggest that 50 μg of fentanyl added to 0.5% bupivacaine increases patient comfort and improves the quality of epidural anaesthesia for caesarean section, and that adding 100 μg does not give further advantage.     

Comparison of epidural anaesthesia with ropivacaine 0.5% and bupivacaine 0.5% for Caesarean section

PURPOSE: To compare ropivacaine 0.5% with bupivacaine 0.5% for epidural anaesthesia for Caesarean section. METHODS: Healthy pregnant women, scheduled for elective Caesarean section were enrolled into this randomized, double-blind, parallel-group study. Epidural block was obtained with 20-30 ml of ropivacaine (group R) or bupivacaine (group B) and surgery started when anaesthesia was reached T6. Maternal heart rate and blood pressure and fetal heart rate were assessed before the test dose and at five minute intervals until the end of surgery. At the same intervals, sensory and motor block characteristics were determined. Apgar scores and Neurologic and Adaptive Capacity Scores (NACS) were determined after delivery. Adverse events were recorded. RESULTS: Sixty-five patients were enrolled and data from 61 were available for analysis; 30 ropivacaine and 31 bupivacaine. Time from the end of the last injection to the start of surgery was 46 +/- 13 min (mean +/- SD) in gp R and 53 +/- 25 min in gp B (P:NS). The median duration of analgesia varied between 1.7 and 4.2 hr in gp R and between 1.8 and 4.4 hr in gp B (P:NS). In patients who developed Bromage 4 block, it persisted longer in those in gp B (2.5 hr) than in gp R (0.9 hr) (P < 0.05). The quality of analgesia was satisfactory in 27/29 patients (93%) in gp R and 27/31 patients (87%) in gp B (P:NS), although supplemental i.v. opioid was required in ten and seven patients, respectively. The most common adverse events in the mother were hypotension (63% gp R and 61% in gp B) (NS) and nausea (30% and 58%, in group R and B, respectively) (P = 0.05). Apgar scores were 7 after five minutes in all neonates. CONCLUSION: Ropivacaine 0.5% and bupivacaine 0.5% provided effective epidural anaesthesia for Caesarean section although supplementation with i.v. opioid was commonly required.