Non-neuraxial analgesia in labour

Pain in labour is often described as one of the most severe pains experienced. Neuraxial techniques provide the most effective form of labour analgesia. However, not all women wish to have this or indeed want complete pain relief in labour. There are also subgroups of women in whom neuraxial techniques are contraindicated or attempted placement is unsuccessful. Therefore delivery units must be able to offer a range of non-neuraxial analgesia options for labour.     

Non-neuraxial analgesia in labour

Pain in labour is often described as one of the most severe pains known. Neuraxial techniques provide the most effective form of labour analgesia. However, not all women wish to have a neuraxial technique or indeed want complete pain relief for labour. There are also subgroups of women in whom neuraxial techniques are contraindicated or attempted placement is unsuccessful. Therefore delivery units must be able to offer a range of non-neuraxial analgesia options for labour.     

瑞芬太尼用于产妇静脉自控镇痛分娩进展

瑞芬太尼具有起效快、时量半衰期短而恒定的药动学特点,是短时间、间断性分娩镇痛的理想药物.现在已有一些关于瑞芬太尼分娩镇痛的报道,报道认为瑞芬太尼静脉自控镇痛能够提供有效的镇痛,具有副作用小、产妇满意度高的特点.     

Comparison of remifentanil and nitrous oxide in labour analgesia

BACKGROUND: We compared the efficacy and side-effects of remifentanil with those of nitrous oxide during the first stage of labour. METHODS: Twenty parturients participated in a randomized, double-blind, cross-over study. Intravenous remifentanil in 0.4 microg kg(-1) PCA doses with 1-min infusion and lock-out times and intermittent inhaled 50% nitrous oxide were compared during 20-min study periods with a 20-min wash-out sequence after each period. The parturients assessed the intensity of contraction pain (verbal numerical score 0-10), pain relief (score 0-4) and side-effects every 10 min. Noninvasive blood pressure, heart rate (HR), oxyhaemoglobin saturation (SaO2), end-tidal carbon dioxide, fractions of inhaled and exhaled oxygen and nitrous oxide and foetal heart rate (FHR) were recorded. Hypoxaemia and bradycardia were defined as SaO2<90% and HR<50, respectively. RESULTS: Fifteen parturients completed the study. There was no period effect or treatment-period interaction. The median decrease in pain score for remifentanil was 1.5 and that for nitrous oxide 0.5 (P=0.01). The parturients gave better pain relief scores with remifentanil than with nitrous oxide (median 2.5 vs. 0.5, respectively, P<0.001). Sedation was reported more often, and SaO2 was slightly lower during remifentanil administration. No episodes of hypoxaemia occurred. There was no difference in maternal blood pressure and HR or the incidence of abnormal FHR during remifentanil compared to nitrous oxide. Most parturients preferred remifentanil to nitrous oxide (14 vs. 1, P<0.001). CONCLUSIONS: This study suggests that IVPCA remifentanil provides better labour analgesia than intermittently inhaled nitrous oxide.     

Patient-controlled analgesia using remifentanil in the parturient with thrombocytopaenia

Patient-controlled intravenous remifentanil was used to provide analgesia in labour for three thrombocytopaenic women. The most successful regimen comprised a patient-demand bolus of 0.5 microg x kg(-1) with a lockout period of 2-3 min, allowing for a successful demand with each contraction. There was an initial period during which the patient learned to anticipate the next contraction and to deliver a bolus about 30 s beforehand; subsequently the remifentanil provided excellent analgesia, with a range of consumption of 426-1050 microg x h(-1). Apart from one episode of maternal sedation and fetal heart rate decelerations resulting from an excessive demand bolus, mothers and neonates tolerated the remifentanil without sequelae. Owing to rapid metabolism by tissue esterase, the use of remifentanil allows adequate doses of opioid to be administered to the mother to achieve good analgesia, without its accumulation in the fetus.     

A comparison of patient-controlled analgesia administered by the intravenous or intranasal route during the early postoperative period

Intranasal administration of lipophilic opioids has been shown to be an effective method of administration which is devoid of major side-effects. Whether it is as effective as intravenous administration for patient-controlled analgesia (PCA) has been investigated for fentanyl and pethidine, but not for diamorphine. This study reports a randomised controlled trial designed to compare the effectiveness of diamorphine administered as PCA utilising either the intranasal or intravenous routes. We investigated 52 consecutive patients undergoing primary lower limb joint replacement surgery. Patients were randomly allocated to receive PCA diamorphine, administered either intravenously (0.5 mg bolus, 3 min lockout) or intranasally (1.0 mg bolus, 3 min lockout). Pain was assessed using a Visual Analogue Score (VAS) at rest and on movement on five occasions over the first 36 h postoperatively. The results demonstrated that patients in the intranasal PCA group had significantly higher VAS scores than the intravenous group, both at rest (intranasal median 35.5 vs. intravenous median 20; p = 0.030) and on movement (intranasal median 64 vs. intravenous median 50; p = 0.016). However, significantly fewer patients in the intranasal group compared with the intravenous group suffered episodes of vomiting (intranasal 0/24 vs. intravenous 6/24 patients; p = 0.022). We suggest that if a maximal reduction in pain score is considered the goal of PCA management, the intravenous route is preferable to the intranasal route.     

Patient-controlled analgesia for labour using remifentanil: a feasibility study

We have investigated the efficacy and safety of remifentanilin a patient-controlled analgesia device for labour in 21 women.Remifentanil was available in increasing doses (bolus doses0.25–1.0 µg kg^–1) with and without a backgroundinfusion (0.025–0.05 µg kg^–1 min^–1).A lockout time of 2 min was used. Thirteen out of 21 (62%) womenchose to continue using remifentanil up to and during delivery.Nineteen out of 21 (90%) achieved a reduction in pain scorefrom baseline. Using a VAS of 0–10 cm the median maximumreduction in pain score was 3 cm (range 0–8 cm). Therewas a significant reduction (P<0.05) from baseline pain scores(median= 8 cm) to scores at bolus doses in the range 0.25–0.5µg kg^–1 (median=5 cm). There were no significantreductions in the fetal heart rate. Apgar scores and cord bloodgas analyses remained within normal limits. We conclude thata remifentanil patient-controlled analgesia system (bolus doses0.25–0.5 µg kg^–1, without a background infusion)may safely provide worthwhile, although incomplete, analgesiafor labour. Br J Anaesth 2001; 87: 415–20     

规模化分娩镇痛的可行性

目的 评价规模化开展分娩镇痛的可行性。方法 自愿接受分娩镇痛及无产科及麻醉禁忌证的足月孕初产妇819例,全部采用腰麻-硬膜外联合镇痛(CESA)和病人自控镇痛(PCEA)的分娩镇痛法。进入活跃期时,蛛网膜下腔注射0.2％罗哌卡因3mg后30min,PCEA输注0.1％罗哌卡因与2μg/mg芬太尼的混合液,按PCA 6ml/15min,或持续背景速度9ml/h,按需追加3ml/h,于宫口开全停泵。结果 CSEA后VAS从镇痛前的(84.2±13.3)分迅速降至(5.4±6.4)分,且差异具有非常显著性(P<0.01)。PCEA总量0-117ml(25±17)ml;罗哌卡因(11.9±4.7)ml/h;芬太尼(23.8±9.4)μg/h;整个产程VAS评分0-40分,镇痛总有效率为96.1％。99.1％镇痛后Bromage标准0级,可下地行走。分娩镇痛率为32.7％,其中剖宫产率26.7％,低于同期的45.4％总剖宫产率;器械助产率为11.6％略高于同期9.3％的总器械助产率。低血压发生率为4.7％、恶心0.6％、皮肤瘙痒0.5％,产后头痛0.4％和尿潴留0.6％。结论CSEA+PCEA和罗哌卡因的使用,可有效降低剖宫产率,增加自然分娩率,并产生极少不良反应和最小的运动神经阻滞,对母婴安全有益。但观念的更新及分娩镇痛服务体系的建立更重要。     

A randomised comparison of intravenous remifentanil patient-controlled analgesia with epidural ropivacaine/sufentanil during labour

Background

The μ-opioid agonist remifentanil has a rapid onset and offset and a short half-life making it an attractive option for intravenous patient-controlled labour analgesia. We aimed to compare the efficacy of intravenous remifentanil patient-controlled analgesia with epidural ropivacaine/sufentanil during labour.

Methods

Parturients were randomly assigned to receive intravenous patient-controlled analgesia with remifentanil (n = 10) or epidural analgesia (n = 10). Pain and satisfaction scores were assessed every hour by means of visual analogue scale, together with an observer sedation score. Side effects and neonatal outcome were noted.

Results

After one hour, visual analogue pain scores had decreased significantly in both groups (remifentanil: −3.8 ± 2.6, P < 0.01; epidural −6.7 ± 2.0, P < 0.01). The decrease in pain scores in the epidural group was significantly greater than the remifentanil group at all time intervals. The decrease in pain scores was sustained in the epidural group whereas in the remifentanil group pain scores increased over time. Oxygen saturation was significantly lower in the remifentanil group after one hour of treatment compared to the epidural group (95.2 ± 2.4% vs. 99.0 ± 1.1%, P < 0.01). Patient satisfaction scores during and after delivery were similar in both groups. No differences were found in neonatal outcome.

Conclusions

In the 20 patients recruited to this study, pain relief in labour with epidural ropivacaine/sufentanil was more effective than with intravenous remifentanil patient-controlled analgesia.     

Intravenous remifentanil vs. epidural levobupivacaine with fentanyl for pain relief in early labour: a randomised, controlled, double-blinded study

Background: We hypothesised that intravenous patient-controlled analgesia (IV PCA) with remifentanil could provide as satisfactory pain relief for labour as epidural analgesia.
Methods: Fifty-two parturients with singleton uncomplicated pregnancies were randomised to receive either IV PCA with remifentanil or epidural analgesia with 20 ml levobupivacaine 0.625 mg/ml and fentanyl 2 μg/ml in saline. The PCA dose of remifentanil was given over 1 min with a lockout time of 1 min. The dose was increased starting from the bolus of 0.1 μg/kg and following a dose escalation scheme up until the individual-effective dose was reached. The parturients assessed contraction pain (0–10), pain relief (0–4), sedation and nausea during 60 min.
Results: Forty-five parturients were included in the analysis. The median cervical opening was 4 cm before the study and 7 cm after the study. The median pain scores were 7.3 and 5.2 during remifentanil and epidural analgesia, respectively (P=0.009). The median pain relief scores were 2.5 and 2.8 (P=0.17). There was no difference between the groups in the proportion of parturients who discontinued due to ineffective analgesia, nor in the proportion of parturients who would have liked to continue the given medication at the end of the study. Sedation and low haemoglobin oxygen saturation were observed more often during remifentanil analgesia. Foetal heart rate tracing abnormalities were as common in both groups.
Conclusions: In terms of pain scores, epidural analgesia is superior to that provided by IV remifentanil. However, there was no difference in the pain relief scores between the treatments.     

Comparison of patient-controlled analgesia with and without a background infusion after appendicectomy in children

BACKGROUND: There have been many studies using patient-controlled analgesia (PCA) and opioids for postoperative analgesia in children. In this study, we investigated the efficacy, usefulness and analgesic consumption of two different PCA programmes [bolus dose alone (BD) or bolus dose with background infusion (BD + BI)] to evaluate postoperative analgesia for children after emergency appendicectomy. METHODS: Forty children, aged between 6 and 15 years and ASA class I or II, undergoing emergency appendicectomy were randomly allocated into two groups. The children were given a loading dose of pethidine 0.3 mg.kg-1 and 150 micro g.kg-1 bolus intravenously in group BD (n = 20) and pethidine 0.3 mg.kg-1 loading dose, 75 micro g.kg-1 bolus and 15 micro g.kg-1.h-1 background infusion in group BD + BI (n = 20). The lockout interval was 20 min in both groups. RESULTS: There were no significant differences in pain, sedation and nausea scores during the 24-h postoperative period between the groups (P > 0.05). Pethidine consumption was significantly lower in group BD + BI than that in group BD for the first 24-h period (P < 0.05). CONCLUSIONS: We demonstrated that both these PCA programmes were effective and reliable for postoperative pain relief in children. We believe that giving information about PCA to the children and their parents is useful during the preoperative period. However, the background infusion with lower bolus dose in PCA did not increase pethidine consumption.     

A case series of vital signs‐controlled,patient‐assisted intravenous analgesia (VPIA) using remifentanil for labour and delivery

Intravenous remifentanil patient‐controlled analgesia can be used during labour as an alternative to epidural analgesia. Adverse effects of opioids, including hypoxia and bradycardia, may lead to maternal morbidity and mortality. We devised an interactive feedback system based on a clinical proportional algorithm, to continuously monitor for adverse effects to enhance safety and better titrate analgesia. This vital signs‐controlled, patient‐assisted intravenous analgesia with remifentanil used a prototype delivery system linked to a pulse oximeter that evaluated maternal oxygen saturation and heart rate continuously. With this system, we detected oxygen saturation < 95% for more than 60 s in 15 of 29 subjects (52%); and heart rate < 60 min^?1 for more than 60 s in 7 of 29 subjects (24%) during use. The system automatically responded appropriately by reducing the dosages and temporarily halting remifentanil administration, thus averting further hypoxia and bradycardia.     

骨科下肢手术患儿术后父母控制静脉镇痛的效应

目的 评价骨科下肢手术患儿术后父母控制静脉镇痛的效应.方法 择期行骨科下肢矫形手术患儿507例,ASA Ⅰ或Ⅱ级,年龄10月～8岁,8.5～34.0 kg.按年龄分为2组:<6岁的患儿采用父母控制静脉镇痛组(n=308);≥6岁的患儿采用自控静脉镇痛组(n=199).气管插管或喉罩全麻复合0.25%布比卡因骶管阻滞下进行手术,术后给予吗啡镇痛,背景输注速率15μg~(-1)·kg~(-1)·h,PCA量15μg/kg,锁定时间10 min.于术后4、24、48 h时,采用Wong-Baker面部表情评分法或改良面部表情评分法评价疼痛程度;采用Ramsay评分评价镇静程度.于术后24、48 h时记录PCA次数和吗啡剂量;记录术后48 h内不良反应的发生情况.结果 两组术后镇痛效果、镇静水平、PCA次数、吗啡剂量和不良反应发生率差异无统计学意义(P>0.05).结论 父母控制静脉镇痛可安全、有效地用于骨科下肢手术患儿术后镇痛.     

A randomised double-blind evaluation of adenosine as adjunct to sufentanil in spinal labour analgesia

BACKGROUND: Intrathecal injection of sufentanil offers labour pain relief of short duration. This double-blind randomised study evaluates if the combination of adenosine to sufentanil could give relevant prolongation (40%) of the duration of sufentanil spinal analgesia. METHODS: Twenty-five healthy parturients requesting labour analgesia were included. Patients received 10 micro g of sufentanil + 500 micro g of adenosine or 10 micro g of sufentanil intrathecally. Pain intensity and duration of pain relief were assessed. RESULTS: Pain relief was equal between groups. Duration of analgesia was not increased by adenosine + sufentanil, 99 +/- 54 min, vs. sufentanil, 89 +/- 56 min. CONCLUSION: Adding 500 micro g of adenosine to 10 micro g of sufentanil could not provide any prolongation of labour pain relief.     

Patient-controlled analgesia

A patient received a massive overdose of papaveretum intravenously (estimated to be 180 mg) when the glass syringe of a patient-controlled analgesia machine disengaged from the drive mechanism. She was successfully resuscitated. The pump, on loan from the supplier, had passed a brief evaluation by the infusion pump test house designated by the Medical Devices Directorate of the Department of Health; it has since been withdrawn. It is recommended that patient-controlled analgesia equipment should be placed at or below patient heart level. The Department of Health is called on to institute a full, independent evaluation scheme for patient-controlled analgesia equipment.     

硬膜外分娩镇痛的研究进展

硬膜外分娩镇痛对分娩的影响一直存在争议.新近资料不仅提供了硬膜外分娩镇痛对产程、剖宫产率、阴道器械助产率、及新生儿影响的进展,而且它与持续性枕后位和产妇发烧的关系也受到关注.改进硬膜外分娩镇痛技术的关键是减小对分娩不利影响并保证产妇满意镇痛的重要手段.研究表明采用低浓度局麻药复合阿片类药硬膜外镇痛,设置大容量PCEA和长锁定时间的输注模式对分娩的影响最小.     

Comparison of patient-controlled epidural bolus administration of 0.1% ropivacaine and 0.1% levobupivacaine, both with 0.0002% fentanyl, for analgesia during labour

The aim of the study was to compare the relative potencies and clinical characteristics of epidural ropivacaine and levobupivacaine in labour using patient-controlled epidural analgesia (PCEA). In a randomised double-blinded study, 60 ASA I or II primigravidae requesting epidural analgesia in early labour were allocated to receive either 0.1% ropivacaine with fentanyl 0.0002% or 0.1% levobupivacaine with 0.0002% fentanyl via a patient-controlled analgesia pump. Analgesia was established with 15 ml of study solution and maintained using 5-ml boluses of study solution with a 5-min lockout interval. There were no significant differences in onset time, duration and quality of analgesia, motor and sensory blockade, local anaesthetic consumption, mode of delivery, neonatal outcome or maternal satisfaction between the groups. We conclude that 0.1% ropivacaine with 0.0002% fentanyl and 0.1% levobupivacaine with 0.0002% fentanyl are clinically indistinguishable for labour analgesia and appear pharmacologically equipotent when using PCEA.     

Long-term patient-controlled analgesia in children

Three children who received patient-controlled analgesia for periods of up to 41 days are described. In each case patient-controlled analgesia allowed pain control to be achieved in difficult situations. No patient developed tolerance or clinical signs of dependence. This use of long-term patient-controlled analgesia warrants further evaluation.