Epidural pethidine and bupivacaine in labour

A double-blind randomised study was performed to assess the value of the addition of pethidine 50 mg to the initial dose of bupivacaine given for epidural analgesia in labour. Forty-nine patients received either 1 ml of saline (n = 24), or 50 mg of pethidine (n = 25), added to 9 ml of 0.25% bupivacaine as an initial injection for intrapartum epidural analgesia. There was a significant increase in the mean duration of analgesia in the pethidine group. However, pethidine did not increase the speed of onset of analgesia, or improve the quality of analgesia.     

Randomized controlled comparison of epidural bupivacaine versus pethidine for analgesia in labour

We compared the incidence of Caesarean delivery in nulliparouswomen randomized to receive epidural analgesia with those randomizedto intramuscular (i.m.) pethidine. On admission to the deliverysuite in established labour, 802 nulliparae had already agreedto be randomized with respect to their first analgesia. Onehundred and eighty-eight women required either no analgesiaor 50% nitrous oxide in oxygen (Entonox) only. Of the remaining614 women, 310 were randomly allocated to receive i.m. pethidineup to 300 mg and 304 to receive epidural bupivacaine. Labourmanagement was standardized according to the criteria for activemanagement of labour. The intention-to-treat analysis showedsimilar Caesarean section rates in those randomized to epidural(12%) or pethidine analgesia (13%). The difference in Caesareanrate was –1.1% with 95% confidence intervals from –6.3%to +4.1%. The normal vaginal delivery rates were similar (epidural,59%; pethidine, 61%).     

The addition of pethidine to epidural bupivacaine in labour--effect of changing bupivacaine strength.

The effects of varying the strength of bupivacaine used in epidurals for the relief of labour pain was examined. The trial randomly allocated sixty women in the first stage of labour to one of three groups. All women were of ASA status 1 or 2 and had uncomplicated pregnancies. Subjects in each group received pethidine 25 mg in 10 ml of either 0.125%, 0.1875%, or 0.25% bupivacaine. Pain scores for each patient were then assessed over the following thirty minutes. Duration of analgesia and subsequent dose requirements were examined. No difference in pain scores between groups at thirty minutes after injection of the test solutions was found. The 0.25% solution group did however have a more rapid onset of analgesia with the majority of patients in this group achieving their maximum effect between ten and twenty minutes after injection. Duration of analgesia was not prolonged by using the stronger solutions. This study suggests that when epidural pethidine 25 mg is added to local anaesthetic solutions of bupivacaine, adequate analgesia for the first stage of labour is achieved with the 0.125% bupivacaine solution. The use of stronger solutions of bupivacaine achieves no greater degree of analgesia nor longer duration of action, although the onset of analgesia may be faster with the stronger solutions. Further investigations are needed to determine if 25 mg of pethidine is the best choice of dose to use under these circumstances.     

Continuous epidural infusion of bupivacaine in labour

Thirty patients were given a constant epidural infusion in labour by gravity feed drip of approximately 10 ml of 0.25% bupivacaine per hr. The infusion proved a simple and reliable method of ensuring adequate analgesia throughout labour. There were no problems of drug toxicity and the incidence of complications and side effects was comparable to a previous series using intermittent 0.5% bupivacaine.     

The addition of fentanyl to epidural bupivacaine in first stage labour

Epidural analgesia was studied in 100 healthy Chinese women with uncomplicated pregnancies in first stage labour. Patients were randomly allocated to receive 8 ml of one of the following five solutions: bupivacaine 0.125% with fentanyl 50 micrograms or fentanyl 100 micrograms, bupivacaine 0.25% plain, bupivacaine 0.25% with fentanyl 50 micrograms or fentanyl 100 micrograms. There was no difference in quality of analgesia among groups as measured by the reduction of visual analogue pain scores 20 minutes after the epidural dose. The duration of analgesia was similar among groups with the overall median duration being 105 minutes. There was no difference in method of delivery or neonatal Apgar scores. The least concentrated mixture providing good quality analgesia for the first stage of labour was the combination of bupivacaine 0.125% with fentanyl 50 micrograms.     

Profound motor blockade with epidural ropivacaine following spinal bupivacaine

Ropivacaine, a relatively new amide local anaesthetic, reputedly produces less motor block than equivalent doses of bupivacaine, potentially combining high-quality analgesia with the ability to ambulate. We report two cases of prolonged, profound motor block with patient-controlled epidural analgesia using 0.1% ropivacaine, following spinal bupivacaine for Caesarean section. As there was no evidence of inadvertent intrathecal ropivacaine administration or of any neurological injury, we hypothesise that epidural ropivacaine may interact with intrathecal bupivacaine to prolong its effect.     

The effect of a priming epidural injection of adrenaline on epidural blockade with bupivacaine

Twenty-four patients receiving epidural anaesthesia were studied to test the hypothesis that 1:200,000 adrenaline administered into the epidural space 5 minutes before 20 ml bupivacaine 0.5% would improve nerve block and delay systemic absorption of the local anaesthetic. Group A/B received 20 ml adrenaline 1:200,000 5 minutes before 20 ml bupivacaine 0.5%, group S/BA 20 ml saline followed by 20 ml bupivacaine 0.5% with 100 micrograms adrenaline, and group S/B saline 20 ml followed by 20 ml plain bupivacaine 0.5%. Mean maximum plasma concentrations of bupivacaine tended to be lower in the adrenaline groups. A delay in the time to peak plasma concentration of bupivacaine was noted in the A/B group; this indicated that priming with adrenaline may be effective at delaying early systemic uptake of the local anaesthetic. In both adrenaline groups a more prolonged epidural block and increased efficacy were noted, although this was only significant for the duration of block at T6 (p = 0.023) and duration of motor block at Bromage level 1 (p = 0.016) in group A/B. There seems little clinical advantage in administering adrenaline 5 minutes before bupivacaine.     

Parturients' assessment of water blocks, pethidine, nitrous oxide, paracervical and epidural blocks in labour

This prospective study evaluated the extent to which the analgesic procedures available resulted in efficient pain relief in 833 Finnish parturients. Their pain ratings were recorded according to their own assessment of pain intensity during labour before and after pain management and according to their total pain experience recalled on the third day after delivery. Only regional blocks significantly diminished pain scores during labour and a striking decrease in pain level (P < 0.0001) was maintained until the second stage by epidural analgesia (EDA) alone. The EDA-group consisted mainly of the primiparous (71%) with induced (17%) and most painful deliveries. After delivery 60% of parturients in this group recalled labour pain as being very severe or intolerable. This was partly due to delays in receiving epidural blockade and partly due to the parturient's reticence in requesting analgesia. Pain relief was rated as excellent or good by 94% of the EDA group but by only 50% of the remaining patients.     

碱化丁哌卡因硬膜外阻滞的药效学与药代动力学观察

目的:观察碱化与非碱化丁哌卡因硬膜外阻滞的药效学与药动学。方法:选择ASA Ⅰ～Ⅱ级行下肢手术患者60例。随机分成两组,每组30例。均用0.75％丁哌卡因1.5mg/kg行硬膜外阻滞,对比观察麻醉效果,并对碱化组中的8例,对照组中的6例作药代动力学研究。结果:与对照组比,碱化组起效时间和阻滞完善时间短,镇痛时间长,感觉神经阻滞节段数多(P<0.01)。两组药代动力学指标无显著差异(P>0.05)。结论:碱化丁哌卡因用于硬膜外阻滞,其效果优于非碱化丁哌卡因。     

Pain threshold and subjectively perceived epidural sensory blockade with 0.5% bupivacaine

We investigated the relationship between patients' pain thresholds and the quality of the subjectively perceived epidural sensory blockade (SPESB). The pain thresholds of 50 patients were evaluated with a modification of the submaximum effort tourniquet technique. There was a significant correlation between pain threshold and the number of subjectively perceived anesthetic and analgesic segments, the likelihood of developing an extensive SPESB being greater in patients with higher pain thresholds. Forty-one percent of patients with pain scores of less than 10 mm on the visual analogue scale, but no patient with a pain score of 20 mm or more, developed anesthesia in ten or more spinal segments.     

Comparison of epidural and spinal blockade with 0.5% bupivacaine for transurethral surgery

The suitability of spinal versus epidural blockade for transurethral resection of the prostate was studied in 60 patients randomly allocated to spinal and epidural anaesthesia groups. 0.5% bupivacaine (Marcain, Astra, Sweden) was injected at the L3-L4 interspace, the dose being 3 ml in the spinal group and 19 (16-25) ml in the epidural group. The blood pressure decreased similarly after both epidural and spinal injections, but the heart rate was not significantly altered. No statistically significant differences were found between the groups in any of the variables measured, including blood pressure, heart rate, intraoperative blood loss and per- and post-operative complications. However, altogether eight patients in the epidural group, but none in the spinal group, had to be treated because of hypotension (P less than 0.001). The main advantage of the spinal blockade was a faster and more reliable blockade of the lowest sacral segments, and the main advantage of the epidural blockade was a less pronounced and shorter duration of motor blockade.