EPIDURAL ANALGESIA IN BRITISH OBSTETRICS

Experiences with 300 continuous and 62 single-shot epiduralblocks administered during labour are presented. The main indicationsfor continuous epidural analgesia were inco-ordinate uterineaction, severe pre-eclampsia and failure of orthodox analgesicdrugs to produce satisfactory pain relief. The method can alsobe used with benefit in selected cases of cardiac and respiratorydisease. In hypertonic inco-ordinate uterine action graphicalanalysis of labour demonstrates an increased rate of cervicaldilatation after epidural block in 70 per cent of cases. Inpre-eclampsia a satisfactory reduction of systolic and diastolicblood pressure is produced. Analgesia is virtually completeand the complication rate is acceptably low in experienced hands.Single-shot epidural analgesia is excellent for forceps deliveryand blood loss at delivery is reduced. Epidural analgesia hasa valuable therapeutic role in obstetrics and is one of thebenefits which result from the introduction of a 24-hour residentobstetric anaesthetic service.     

Trial labour conducted under continuous epidural analgesia.

Two hundred Black women who required trial labour for suspected disproportion were adminstered continuous lumbar epidural analgesia by an obstetrician. The effects, side-effects, and results are described and discussed. Epidural block provides safe, effective analgesia for trial labour, and does not adversely affect the delivery or fetal condition.     

Labour epidural analgesia for a woman with hereditary macrothrombocytopenia

Epidural analgesia is often considered as risk of epidural haematoma in a patient with thrombocytopenia. In this observation, uncomplicated epidural analgesia was performed in a pregnant woman with hereditary macrothrombocytopenia. She received continuous epidural labour analgesia for a vaginal delivery with a platelet count at 63x10(9)/l but platelets with high mean platelet volume (20fL) and normal function. No neurological sequelae or excessive bleeding occurred.     

Practice of epidural analgesia for labour pain: a German survey.

Epidural analgesia is one of the preferred methods of analgesia for labour. The aim of the present survey was to evaluate current practice in obstetric analgesia in departments of anaesthesia and to make a comparison with former surveys from Germany and other countries. Questionnaires on the practice of pain relief, especially epidural analgesia, during labour and delivery were sent to 1178 anaesthetic departments in Germany in the second half of 1996. Five hundred and thirty-two completed replies were received, which represent 46.9% of all German obstetric units. The majority of the departments of anaesthesia practising epidural analgesia have an epidural rate of less than 10% and 10.2% of the departments do not offer this method to their parturients. In 86.8% of all units performing epidural analgesia, the epidural catheter is placed by an anaesthetist. Only 6.5% of the units provide a 24-h epidural service which is exclusively assigned to labour and delivery. In 77.8% of the units, this service is not exclusively assigned to obstetrics, but also to other duties. Of the obstetric units offering epidural analgesia, 14.7% have no epidural service at night. Plain local anaesthetics for epidural analgesia are used by 55.9% of the departments, a combination of local anaesthetics with epidural opioids by 28.7%. Epidural analgesia is predominantly (82.2%) maintained by intermittent bolus administration. Although the rate of epidural analgesia increased during recent decades, this method is not offered to all parturients. Further improvements in the use of epidural analgesia for labour seem to be necessary.     

Patient-controlled intravenous analgesia using remifentanil in the parturient

PURPOSE: To show the use of the short acting opioid remifentanil for labour analgesia when epidural analgesia is considered to be contraindicated. CLINICAL FEATURES: After Ethics Committee approval and informed consent, six patients (36-40 wk gestation), in whom epidural analgesia was considered contraindicated (women refusing regional analgesia, presenting with coagulation or platelet abnormalities or sepsis) benefited from patient-controlled intravenous analgesia (PCIA) with remifentanil. The Abbott Lifecare patient-controlled analgesia (PCA) pump with remifentanil 50 microg x ml(-1) was set to deliver remifentanil continuous background infusion of 0.05 microg x kg(-1) x min(-1) and 25 microg boluses with a five minutes lockout period. The PCIA was started when the parturients experienced regular painful contractions (cervical dilatation of at least 4 cm) and stopped just before delivery (cervix fully dilated). Maternal monitoring included non-invasive blood pressure measurements, heart rate, percutaneous arterial oxyhemoglobin saturation and respiratory rate. Percutaneous fetal heart rate was continuously monitored. All patients remained alert or sleepy but easily arousable and were satisfied with their analgesia. No particular side effects have been noticed. Apgar scores were between 6 and 10. CONCLUSION: Remifentanil PCIA combining low continuous background infusion and small bolus doses is an alternative when epidural analgesia in labour is contraindicated. Under careful anesthesia monitoring, the technique seems to be safe for both mother and baby, at least when delivery occurs at or near the normal term of pregnancy.     

Maternal opinion about analgesia for labour. A controlled trial between epidural block and intramuscular pethidine combined with inhalation

In a randomised controlled trial epidural analgesia with bupivacaine 0.5% (mean dose 112.8 mg) was compared with pethidine (mean dose 200 mg) and inhalational analgesia in primipara (28 and 30 mothers) and multipara (17 and 18 mothers). Mothers who had an uneventful pregnancy and labour and agreed to have either treatment were studied during labour and followed-up at interviews for 5 months after delivery. Epidural block was rated significantly superior in respect of pain relief and comfort, there were no differences between the groups in reports of perineal discomfort. Twice as many primipara required forceps delivery after epidural block. Very few mothers, in each group, reported something missing in their experience of childbirth. Two thirds of each group would use the same method again. Epidural block can therefore be recommended to uncommitted mothers as a satisfying and effective method of pain relief for labour.     

Clinical experience with continuous epidural infusion of bupivacaine at 6 ml per hour in obstetrics

Maintenance of continuous epidural analgesiafor obstetrics by slow infusion is a feasible alternative to maintenance by intermittent injection. The method described by Davies and Fettes using 0.25 per cent bupivacaine through a 6 ml/hr capillary flow device (Intraflo®), with the fast-flush cut-off, is simple and convenient. However, failure of the fast-flush valve, resulting in a high flow rate, has been reported. It is therefore imperative that, prior to connecting the pressurized system to the epidural catheter, correct function of the device be verified by observing the flow rate in the microdrip chamber. We have used this method for the past year and found the equipment reliable, but in order to achieve more satisfactory analgesia the concentration of the infusion was increased initially to 0.375per cent, and then reduced to 0.30 per cent. The records of the first 187 patients were reviewed retrospectively. Group I(n = 99) received an infusion of 0.25 per cent bupivacaine, Group II (n = 49) received 0.30 per cent and Group II (n = 39) received 0.375 per cent. Significantly more patients in Group I (30 per cent) required supplementary top-ups (in addition to the infusion) for the first stage of labour than in either Group II (10 per cent), or Group III (13 per cent). Top-ups for delivery were given to 55 per cent of patients in Group I, 64 per cent in Group II and 48 per cent in Group III. The incidence of motor block was significantly higher in Group III (21 per cent) than in either Group 1(1 per cent) or Group II (2 per cent). For continuous epidural infusion at 6 ml/hr, 0.30 per cent bupivacaine combines optimum analgesia with minimal side-effects.     

Continuous versus intermittent epidural analgesia

A randomised study of 381 women was carried out to compare the obstetric outcome after epidural analgesia maintained by an intermittent top-up regimen or with a continuous infusion. The two groups were well matched with respect to age, parity, mode of onset of labour and indication for epidural. Maintenance of epidural analgesia by continuous infusion resulted in a significantly decreased need for top-up doses. A reduction in the incidence of hypotension, cardiotocographic evidence of intrapartum fetal hypoxia and Caesarean section was associated with this. It is concluded that the maintenance of epidural analgesia by continuous infusion is a safe and reliable method and may be more advantageous and less labour intensive than the traditional intermittent regimen.     

新斯的明降低分娩期患者A控硬膜外镇痛（PCEA）的布比卡因用量：一项随机对照研究

背景鞘内注射新斯的明产生镇痛作用的同时可能导致重度恶心。相反,硬膜外注射新斯的明可以增强阿片类药物和局部麻醉药的镇痛作用而不产生恶心呕吐。以往的研究只针对单次硬膜外注射新斯的明,而对连续硬膜外注射新斯的明和母婴安全性未进行评估。因此,本研究拟验证在分娩期患者中新斯的明复合布比卡因硬膜外注射是否减少布比卡因用量。方法12例择期剖宫产的健康产妇随机分组,分别接受40μg（n=6）和80μg（n=6）新斯的明单次注射,监测20分钟胎心率（fetalheartrate,FHR）和宫缩。然后,另外40例健康的分娩期产妇随机分组,分别接受布比卡因1．25mg／ml或联合新斯的明4μg／ml产妇自控硬膜外镇痛（patient—controlledepiduralanalgesia,PCEA）。主要观察指标为每小时布比卡因用量。结果硬膜外新斯的明单次注射未导致FHR基础值改变,未诱导宫缩或产生恶心。硬膜外新斯的明的使用可使全部产妇的布比卡因用量减少19％,P〈0．05（使用4小时以上产妇用量减少达25％,P〈0．05）,但可能导致轻度镇静。两组产妇的分娩方式、恶心发生率和FHR异常情况均相似。结论以上数据显示硬膜外使用新斯的明可降低PCEA中布比卡因每小时需要量的19％-25％。单次给药和连续注射新斯的明均不会诱发恶心、诱导宫缩或FHR异常,但可能导致轻度镇静。     

The combined spinal-epidural technique

Epidural and spinal blocks are well-accepted regional techniques, but they have several disadvantages. The CSE technique can reduce or eliminate the risks of these disadvantages. CSE block combines the rapidity, density, and reliability of the subarachnoid block with the flexibility of continuous epidural block to extend duration of analgesia. The CSE technique is used routinely at many institutions, particularly for major orthopedic surgery and in obstetrics. It has been used in tens of thousands of patients without any reports of major problems. Although at first sight the CSE technique appears to be more complicated than epidural or spinal block alone, intrathecal drug administration and siting of the epidural catheter are both enhanced by the combined, single-space, needle-through-needle method. Concerns about the epidural catheter entering the theca via the small puncture hole are now considered to be unfounded, but as with all epidural catheter techniques, vigilant monitoring of the patient during and after any injection is paramount. CSE is an effective way to reduce the total drug dosage required for anesthesia or analgesia. The intrathecal injection achieves rapid onset with minimal doses of local anesthetics and opioids, and the block can be prolonged with low-dose epidural maintenance administration. In addition, the sequential CSE method can be used to extend the dermatomal block with minimal additional drugs or even saline. Reduction in total drug dosage has made truly selective blockade possible. Many studies have confirmed that low-dose CSE with local anesthetic and opioid, or low-dose epidural block alone, will provide effective analgesia with minimal motor and proprioceptive block. Such neurologic selective blockade has made it possible for most patients to walk and bear down normally in labor or postoperatively. There remains concern about the risk of infection being increased when the CSE technique is used in place of epidural block alone. Despite a recent flurry of reports of meningitis with CSE procedures, there is no evidence the CSE block is more hazardous than epidural or subarachnoid block alone. Arguably, the single-space, needle-through-needle CSE technique will continue to improve with new needle designs and other advances to improve further the success rate and reduce complications, such as neurotrauma, PDPH, and infection. Over the past decade it has become clear that the CSE technique is a significant advance in regional blockade.     

硬膜外分娩镇痛对分娩方式的影响

目的 评价硬膜外分娩镇痛对分娩方式的影响.方法 初产妇400例,ASA Ⅰ或Ⅱ级,足月、单胎、头位,无妊娠并发症及硬膜外麻醉禁忌证.分为硬膜外镇痛组和非镇痛组(n=200).硬膜外镇痛组宫口开至3 cm时,采用0.1%罗哌卡因混合0.5 μg/ml舒芬太尼行硬膜外镇痛,宫口开全后停止镇痛.记录镇痛前和镇痛15 min时VAS评分;评价运动阻滞程度;记录分娩方式、第一产程、第二产程、新生儿出生后1、5 min时Apgar评分和新生儿体重;记录镇痛过程中不良反应的发生情况.结果 硬膜外镇痛组镇痛15 min时VAS评分由(8.3±0.8)分降至(1.6±1.1)分(P＜0.05).与非镇痛组比较,硬膜外镇痛组顺产率和阴道器械助产率升高,剖宫产率降低,第一产程和第二产程延长(P＜0.05).2组新生儿出生后1、5 min时Apgar评分和新生儿体重比较差异无统计学意义(P＜0.05).硬膜外镇痛组下肢运动阻滞发生率为0.5%,下肢麻木发生率为9.0%,恶心呕吐发生率为1.5%.结论 硬膜外分娩镇痛可降低剖宫产率,提高自然分娩率.     

Ropivacaine 1 mg/ml,plus fentanyl 2 μg/ml for epidural analgesia during labour. Is mode of administration important?

BACKGROUND: Patient-controlled epidural analgesia (PCEA) with a moderate to high concentration of bupivacaine in obstetrics has been shown to give comparable analgesia and even higher level of satisfaction compared to continuous epidural infusion. We hypothesised that the use of a very low concentration technique (ropivacaine/fentanyl) might result in excessive dosing in the PCEA group, more motor blockade and a negative impact on spontaneous delivery rate. METHODS: We conducted a randomised, double-blind study of 60 nulliparous women at term comparing low concentration ropivacaine/fentanyl administered in either patient-controlled or fixed continuous infusion mode. Parturients with known predictors of painful deliveries, i.e. breech presentation, primary induction of labour, were not included. Deliveries within 90 min from the start of epidural analgesia were omitted from the evaluation. RESULTS: We found that both groups required a mean of 12 ml/h low concentration mixture (loading and midwife rescue boluses included). There was no difference between groups with respect to spontaneous delivery rate (71%). This low concentration technique resulted in haemodynamic stability without crystalloid preloading, infusion or vasopressor use. Motor blockade of clinical importance was not detected in any patient. CONCLUSION: We conclude that epidural use of ropivacaine 1 mg/ml+fentanyl 2 microg/ml provides effective analgesia with equal volume requirements irrespective of administration mode, with a high spontaneous delivery rate. Choice of PCEA or CEI (continuous epidural infusion) should be directed by other considerations, most importantly compliance of midwife and possible reduction in workload for anaesthesiology staff.     

Epidural analgesia in labour: constant infusion plus patient-controlled boluses

A randomised, single-blind study to investigate patient-controlled epidural analgesia during labour was conducted using a solution of low-dose bupivacaine-fentanyl. Two groups (n = 25 in each) received a constant infusion supplemented by patient demand boluses, and midwife-administered boluses if required, the size of the infusion and patient increments varying between groups. The quality of analgesia, as assessed by pain scores and patient ratings, was high and participant acceptability very high in both groups. Fourteen per cent of participants were withdrawn due to cephalad extension of block to T5 or supplementary bolus requirements outside the study protocol. Epidural side-effects were not troublesome and drug dose utilisation was low. Significantly greater pain relief (P less than 0.04) three hours after commencing patient-controlled epidural analgesia and a trend to fewer women requiring more than two supplementary midwife-administered boluses (P = 0.11) was seen in the group receiving a higher infusion rate. This group used significantly more bupivacaine (P less than 0.04) and fentanyl (P less than 0.001), but this did not appear to be clinically important with respect to degree of motor block or side-effects. Patient-controlled epidural analgesia appears to be an effective and well accepted method of obstetric analgesia and warrants further investigation.     

Postoperative analgesia by combined continuous infusion and patient-controlled epidural analgesia (PCEA) following hip replacement: ropivacaine versus bupivacaine

BACKGROUND: Ropivacaine is a new local anaesthetic, which compared to bupivacaine is less toxic and shows greater sensory and motor block dissociation. We hypothesised that treatment of postoperative pain with a combined regimen of continuous epidural infusion and Patient-Controlled Epidural Analgesia (PCEA) using ropivacaine could have given better results compared with those we had obtained using bupivacaine. METHODS: Patients undergoing total hip replacement were randomly assigned to two groups. They received epidural analgesia for postoperative pain treatment using ropivacaine, 2 mg x ml(-1) or bupivacaine 2 mg x ml(-1). Both drugs were administered as a constant infusion of 6 ml x h(-1) supplemented by PCEA bolus doses of 2 ml. Patients in both groups received morphine intravenously on demand from a patient-controlled analgesia (PCA) device. An independent observer recorded pain scores, intensity of motor block and morphine consumption at regular intervals during the first 24 h after surgery. RESULTS: Fifty-one patients were evaluated. Ropivacaine and bupivacaine, in similar amounts, provided similar results assessed as adequate to very good postoperative analgesia, whereas motor block was significantly more intense in patients treated with bupivacaine. CONCLUSIONS: Despite similar analgesic effects, epidural infusion of ropivacaine combined with PCEA provides higher patient satisfaction than equal doses of bupivacaine due to lack of motor block.     

Combined spinal epidural (CSE) analgesia: technique, management, and outcome of 300 mothers

Epidural analgesia in labour is commonly associated with some degree of lower limb weakness often severe enough to be described as paralysis by the mother. We aimed to produce rapid reliable analgesia with no motor block throughout labour. We report a pilot survey of 300 consecutive women requesting regional analgesia in labour who received a combined spinal epidural blockade (CSE). The initial dose was given into the subarachnoid space and analgesia maintained via an epidural catheter. A subarachnoid injection of 2.5 mg bupivacaine and 25 mug fentanyl was successfully given in 268 women (89.3%). Completely pain-free contractions within 3 min of this injection occurred in 195 women (65%) and in all 300 within 20 min and there was no associated motor block in 291 (97%). 141 women chose to stand, walk or sit in a rocking chair at some time during labour. Only 38 women (12.6%) were immobile during the first stage of labour. Analgesia was maintained via the epidural catheter with bolus doses of 10-15 ml of 0.1% bupivacaine and 0.0002% fentanyl. The mean bupivacaine requirement was 9.5 mg/h throughout the entire duration of analgesia. The incidence of post lumbar puncture headache was 2.3%. Transient hypotension occurred in 24 women (8%) and was treated with 6 mg intravenous boluses of ephedrine. Complete satisfaction with analgesia and mobility was reported 12-24 h post partum by 95% of mothers. The use of this analgesic technique caused no alteration in obstetric management or post partum care of the women.     

Fentanyl added to bupivacaine 0.05% or ropivacaine 0.05% in patient-controlled epidural analgesia in labour

BACKGROUND AND OBJECTIVE: Epidural analgesia is the most effective method for pain relief during labour. The aim was to elucidate the efficacy of ropivacaine 0.05% and bupivacaine 0.05%, which were both combined with fentanyl 0.00015% to provide analgesia in labour. METHODS: Forty nulliparous females were enrolled into the study. After insertion of an epidural catheter, patients were randomly assigned into two groups. Once the os uteri had dilated to 4-5 cm, a bolus of bupivacaine 0.125% 10mL + fentanyl 50 microg (1 mL) in Group 1 patients, and ropivacaine 0.125% 10mL + fentanyl 50 microg (1 mL) in Group 2 patients was administered via the epidural catheter. Then, patient-controlled epidural analgesia was started with a basal infusion of bupivacaine 0.05% 10 mLh(-1) + fentanyl 0.00015% 1.5 pgmL(-1) in Group 1, and ropivacaine 0.05% + fentanyl 1.5 microgmL(-1) in Group 2. When needed, a 10 mL bolus infusion could be given and the lockout time was 20 min. Maternal and fetal haemodynamic variables were monitored before induction and subsequently at 5 min intervals. Using a visual analogue scale assessed the degree of pain. RESULTS: Maternal haemodynamic variables and Apgar scores were not different between the two groups. The second stage of the labour was shorter in Group 2 (P < 0.01). There were no significant differences in patients' assessment of motor block or mode of delivery between groups. CONCLUSIONS: An epidural infusion (10 mLh(-1)) of bupivacaine 0.05% or ropivacaine 0.05% together with fentanyl 1.5 microg mL(-1) provided good and safe analgesia during labour.     

Patient-controlled spinal analgesia for labour and caesarean delivery

Continuous spinal anaesthesia has not been widely used in Australia. Epidural anaesthesia is often inadequate in patients with previous spinal surgery, as distribution of local anaesthetic in the epidural space is unpredictable. Two cases are presented where continuous spinal anaesthesia enabled satisfactory analgesia and anaesthesia to be obtained for labour and caesarean delivery respectively.     

Epidural analgesia for labor: safety and success

Safe and successful provision of epidural analgesia for labor requires an understanding of the risks of the technique and attention to detail when performing the technique. The frequency of the commonest complication of epidural analgesia, accidental dural puncture, can probably best be minimized by regular practice of the technique. Some catheters, intended for the epidural space, will find themselves intrathecal, intravascular, or subdural. Although such misplacements probably cannot be prevented, their consequences can be minimized by careful, incremental injection of small doses of local anesthetic. The traditional epidural “test dose” of 45 mg of lidocaine and 15 μg of epinephrine can have undesired effects when injected intrathecally, intravenously, or epidurally. Successful epidural analgesia requires first placing a catheter in the epidural space. The combined spinal epidural technique is a very reliable way to accomplish this task. Subsequently, an appropriate dose of drug must be injected or infused by using an effective delivery system. Continuous infusion of ultra-dilute solutions of local anesthetics and opioids will relieve labor pain in some women, but the frequent need for supplemental medications severely limits their efficacy. Patient-controlled epidural analgesia, using slightly more concentrated local anesthetic solutions produces excellent analgesia with less local anesthetic and less need for rescue medication than continuous infusion techniques.     

Motor block during epidural infusions for nulliparous women in labour: a randomized double-blind study of plain bupivacaine and low dose bupivacaine with fentanyl

Sixty nulliparous women received epidural infusions in labour of either 0.125% plain bupivacaine or 0.0625% bupivacaine containing 2.5 mcg/ml fentanyl both starting at 12 ml/h and titrated to maintain a sensory block to T10. Those women who received low dose bupivacaine with fentanyl took significantly longer to reach full cervical dilation (P < 0.05). There was no statistical difference between the groups in the number of additional epidural bolus doses required during the infusions. Of the women receiving low dose bupivacaine with fentanyl, 77% required one or no additional top-up doses compared to 87% in the plain bupivacaine group. There was no reduction in the incidence of perineal pain in the group who received fentanyl. Significantly more women who received 0.125% bupivacaine had motor block after 2 h of the infusion (P < 0.05). The mode of delivery was similar in the two groups as was the satisfaction with epidural analgesia in both the first and second stages of labour and with labour overall. There were no significant differences in Apgar scores, umbilical cord blood pH levels or neurologic and adaptive capacity scores at 2 or 24 h. There was no significant difference in the incidence of symptoms 24 h after delivery.     

Addition of clonidine to a continuous patient-controlled epidural infusion of low-concentration levobupivacaine plus sufentanil in primiparous women during labour

We studied the potentiation of analgesia for labour by the addition of clonidine to epidural low-concentration levobupivacaine with sufentanil in a randomised, double-blinded study. We enrolled primiparous women who were in spontaneous labour. The study solutions, made of 100 ml levobupivacaine 0.0625% plus sufentanil 0.45 μg.ml(-1) and either 150 μg clonidine or no clonidine, were used for induction of analgesia, and for its maintenance with self-administered boluses and a continuous background infusion. The need for additional epidural boluses during labour was lower and analgesia and maternal satisfaction were better in the clonidine (n = 57) than in the control group (n = 58). Blood pressure was lower and the rate of instrumental delivery higher in the clonidine group. Clonidine (1.36 μg.ml(-1)) added to the epidural solution of low-concentration levobupivacaine improves the quality of analgesia. The relevance of the haemodynamic effects should be explored in larger validation studies.