Maternal postures and epidural analgesia during labour

The evolution of birth is of interest for obstetricians and midwives. Postures with asymmetric stretching and balance, kneeling, or sitting have been claimed to be able to help foetal head rotation. Although walking during labour have no influence on the outcome of labour, hip-flexed postures enlarging the pelvic diameter are yet evaluated to improve the obstetric course of labour. In a prospective randomised study including 93 parturients, we compared the supine 30 degrees lateral tilt (control group) to three hip-flexed postures: sitting (S), right hip-flexed left lateral position (L) and left hip-flexed right lateral position (R). Epidural analgesia with 12 ml ropivacaine 0.1% and sufentanil 0.5 microg/ml was administered over a period of six minutes. The total epidural spread was 15+/-0.3 dermatomes and the upper level of thermo-analgesic blockade reached T7-T8 (T5 to T10) in each group. There were no differences between groups for the left and right total spread and upper level of epidural blockade, for the time to maximal block and pain relief. There was no motor block and no maternal or foetal side effects. We conclude that, for the three hip-flexed postures tested, position does not influence local anesthetic spread or symmetry of analgesia after induction of obstetric epidural anaesthesia.     

Communications during epidural catheter placement for labour analgesia

Evidence suggests that anaesthetists' communication can affect patient experience. There is a lack of guidance for anaesthetists as to the optimal verbal communication to use during insertion of epidurals on the labour ward. We recorded the verbal communication used by 14 anaesthetists during the siting of epidural catheters in women on the labour ward; a classification of the language used was subsequently devised. We found that commands and information statements were the most common types of communication used. Individual anaesthetists differed markedly in their use of positive and negative verbal language. This classification of verbal communication that we produced may be of value in future training and research of verbal communication used by anaesthetists on the labour ward.     

Uterine rupture and epidural analgesia during trial of labour

A case of complete uterine rupture during a trial of labour in which epidural analgesia was used is described. The pain of uterine rupture was not masked by the addition of fentanyl 25 μg to bupivacaine 0.25% 6 ml but was relieved by bupivacaine 0.375% 6 ml.     

Intrathecal morphine reduces breakthrough pain during labour epidural analgesia

BACKGROUND: When using the combined spinal-epidural (CSE) technique forlabour analgesia, parturients often experience breakthroughpain after the spinal medication has receded. We tested thehypothesis that a small dose of intrathecal morphine would reducebreakthrough pain. METHODS: This was a randomized, double-blind, placebo-controlled trial.Subjects were randomized to receive either 100 µgof morphine (MS) or placebo (PLCB) with the spinal injectionof bupivacaine and fentanyl. Assessments included need for supplementationduring labour analgesia, use of pain medications for 24 hafter delivery, and side-effects. The primary end-point wasthe rate of breakthrough pain. RESULTS: Sixty subjects were enrolled, 55 subjects completed the trial.The MS group had a significantly lower rate of breakthroughpain than the PLCB group [0.6 (0.6) vs 1.1 (0.8) episodes perpatient; P < 0.01], and longer time to first episode of breakthroughpain (300 vs 180 min; P = 0.03). The MS group used 75%less opioid medications during the subsequent 24 h, buthad a 17% incidence of nausea. CONCLUSIONS: The addition of small dose of morphine to the spinal componentof the CSE technique improved the effectiveness of epidurallabour analgesia and reduced the need for pain medications over24 h, but resulted in a small increase in nausea.     

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 three modes of patient-controlled epidural analgesia during labour

BACKGROUND AND OBJECTIVES: This study compares three modes of patient-controlled epidural analgesia in parturients during labour. METHODS: Eighty-four women were randomized to one of three groups. The epidural solution used in all the three groups was 0.1% bupivacaine with fentanyl 2 microg mL(-1). Patients were able to self administer a demand dose of 3 mL with a lockout interval of 6 min in Group A, 6 mL with a lockout interval of 12 min in Group B and 9 mL with lockout interval of 18 min in Group C. All patients received a background infusion at a rate of 6 mL h(-1). Visual analogue pain scores, pinprick analgesia and motor block were assessed hourly by a blinded observer. The physician-administered supplementation and the cumulative dose of bupivacaine were also compared between the three groups. RESULTS: Pain scores, sensory level and motor block were not different among the study groups. Patients' satisfaction was rated good to excellent with no difference among groups. The cumulative dose of bupivacaine was not significantly different. However, there was a trend towards a decreased need for rescue analgesia in Group C. Within each group, the physician-administered supplementations were significantly higher during the second stage of labour than during the first stage (P < 0.05). CONCLUSION: The three modes of patient-controlled epidural analgesia supplemented by a background infusion of 6 mL h(-1) were equally effective for labour analgesia with a trend for decreased rescue analgesia in the group with a larger bolus dose and a longer lockout interval.     

Posterior column sensory impairment during ambulatory extradural analgesia in labour

Ambulatory or ";walking" extradural analgesia in labour hasrecently gained popularity because of preservation of motorfunction and subjective somatic sensation in the lower limbs,resulting in increased maternal satisfaction. This is producedby combining dilute concentrations (e.g. 0.1%) of bupivacainewith opioids. Detailed clinical neurological examination aftermobile extradural analgesia has not been reported. We have investigatedthe effect of 0.1% bupivacaine 15 ml and fentanyl 2µ ml^–1on motor and sensory function in the lower limbs in 50 primigravidaerequesting extradural analgesia in labour. This was performedbefore and 30 min after confirming placement of a lumbar extraduralcatheter. While power, co-ordination and reflexes in all lowerlimb muscle groups remained within normal limits, 66% (n=33)developed abnormal distal proprioception, 44% (n=22) had a positiveRomberg's sign and 38% (n=19) had altered vibration sense. Moreover,44% (n=22) said that their legs felt different on standing andthey did not feel confident walking unaccompanied. However,this subjective perception correlated poorly with the presenceof posterior column sensory signs. Although there was a reductionin pain scores on a visual analogue scale after 30 min (mean8.85 (SEM 0.3) vs 3.06 (0.32); P<0.0001), pain increasedwithin 60 min (5.77 (0.45); P<0.001).     

Effect of epidural analgesia on change in Mallampati class during labour

Mallampati class has been shown to increase during labour. Epidural analgesia might influence this change. The aim of our study was to compare the change in Mallampati class during labour in parturients who did and did not receive epidural analgesia and study the association of these changes with pre‐defined clinical characteristics. We performed a prospective observational study of 190 parturients. Using standard methodology, photographs of the upper airway were taken with a digital camera during early labour and within 90 min of delivery. Two to three consultant anaesthetists, blinded to the origin of the photographs, evaluated the images obtained and assigned a Mallampati class to each. Overall, Mallampati class increased in 61 (32.1%), decreased in 18 (9.5%) and did not change in 111 (58.4%) parturients (p < 0.001). The proportions of parturients in the epidural and non‐epidural groups who demonstrated an increase, decrease and no change in Mallampati class were similar. Of the relationships between change in Mallampati class and the other factors studied, only the total dose of epidural levobupivacaine during labour demonstrated a weak positive correlation 0.17 (p = 0.039) with Mallampati class. This study confirms that labour is associated with an increase in the Mallampati class in approximately one third of parturients. Our findings indicate that having an epidural does not influence the likelihood of a change in Mallampati class during labour.     

Patient controlled epidural analgesia during labour: choice of solution

Epidural characteristics, when using different solutions for patient controlled epidural analgesia (PCEA), were compared in a randomised, blinded study in labour. Women in group 1 (n=23) self-administered 0.25% plain bupivacaine, in group 2 (n=23) 0.125% plain bupivacaine plus fentanyl 3 microg/ml and in group 3 (n=20) 0.0625% bupivacaine with adrenaline 1:250,000 plus fentanyl 3 microg/ml. There were no significant differences between groups with respect to the quality of obstetric pain relief or maternal satisfaction, the requirement for supplementary boluses of staff-administered solution or the incidence of side effects. There was more intense motor block after 3 hours of PCEA (odds ratio 3.33 for score 0 versus 1, 2 or 3) and a significantly higher ratio of demands received to demands made (P<0.03) in group 1 compared groups 2 and 3. The rate of bupivacaine utilisation was significantly higher in group 1 compared to groups 2 and 3 and lower in group 3 compared to 1 and 2 (median+interquartile range: 16+11-21 vs 9+6-11 vs 4+3-8 mg/hr, P<0.0002). Although all solutions provided effective pain relief for PCEA during labour, the use of a low-dose bupivacaine-fentanyl combination offers clinical advantages and further evaluation of such solutions is warranted.     

Parturient-controlled epidural analgesia during labour: bupivacaine vs. ropivacaine

In this randomised, controlled study, we compared the hourly dose requirement of ropivacaine 0.125% (group R, n = 16) with bupivacaine 0.125% (group B, n = 16) provided by demand-only (bolus 5 ml, lockout 10 min) parturient-controlled epidural analgesia during labour. The hourly dose requirement was comparable although group R had a lower successful to total demands ratio (p < 0.05). We also found that both groups were clinically indistinguishable in terms of pain relief and side-effects. No difference in maternal or fetal outcome was detected. We conclude that, at a concentration of 0.125%, ropivacaine and bupivacaine were equally effective when self-administered using this patient-controlled regimen.     

Alternative techniques to labour epidural analgesia

Many systemic techniques, so-called "alternatives" to labor epidural analgesia, have been described: they are all poorly effective and some are associated with significant maternal and neonatal side effects. Nonetheless, these techniques can provide good maternal satisfaction. Accordingly, they are indicated when epidural analgesia is contraindicated or unavailable. Administration of systemic opioids mandates maternal respiratory supervision, oxygen supplementation and/or pulse oxymetry. Systemic opioids may also decrease fetal heart rate variability and produce neonatal respiratory depression; naloxone administration to the neonate is therefore widely indicated. Pethidine should be abandoned because it can produce prolonged neonatal respiratory depression. Nalbuphine produces less nausea/vomiting and less long lasting neonatal respiratory depression. Intravenous PCA fentanyl or sufentanil is presently the method of choice during early labor. Alfentanil seems less effective and may produce more neonatal side effects. Intravenous PCA remifentanil is the most effective technique, but safe administration may be problematic during intermittent supervision usually implemented in labour ward. Nitrous oxide 50% provides little pain relief. Nonetheless, it is associated with few side effects, quite good maternal satisfaction and can be quickly implemented during advanced painful labor. It is not recommended to add it to systemic opioid (except under continuous supervision by the anaesthetic team), because of an increased incidence of maternal desaturation. The use of a subanaesthetic concentration of sevoflurane has been described recently; it is more effective than nitrous oxide. However, guidelines for safe implementation in labor ward remain to be determined.