Epidural analgesia and instrumental delivery

Delivery room analgesia: an analysis of maternal satisfaction

On the first post-partum day, 324 mothers completed a questionnaire designed to assess maternal perception of delivery room experience. Antenatal pain expectation, actual pain severity, analgesia received, as well as maternal satisfaction and choice of analgesia for future deliveries were recorded. Forty-five percent of primiparae and 36% of multiparae reported that they anticipated suffering extreme pain during delivery. The incidence of unbearable pain was similar among patients who received no analgesia or intravenous pethidine but significantly (P<0.0001) higher when compared to epidural analgesia. During the first stage of labour, continuous epidural analgesia was associated with severe or unbearable pain in 51% and 58% of primiparae and multiparae, respectively. The incidence of severe or unbearable pain during the second stage of labour was 43% and 46% for primiparae and multiparae, respectively. Patient satisfaction with epidural analgesia did not correlate with subjective pain scores. Among mothers who received continuous epidural analgesia 70% described their experience as good or excellent and 65.8% indicated that they would request similar pain relief in the future. Despite advances in obstetric analgesia, women anticipate and actually experience severe pain during childbirth. However, due to psychological and cultural factors, as well as possible post-partum euphoria, satisfaction with the delivery room experience is high.

Forceps delivery and the use of synthetic opioid analgesia during epidural anaesthesia

OBJECTIVE

To verify whether the use of sufentanil during obstetric epidural anaesthesia (EA) was accompanied by an increase in the rate of instrumental extraction.

STUDY DESIGN

We made a retrospective comparison of deliveries that occurred during two 3-year periods (1993-1995, and 1997-1999), before and after the introduction of sufentanil into our protocol for epidural anaesthesia.

RESULTS

The first period covered 4694 deliveries compared with 5310 in the second; for these periods, the EA rate rose from 48.55 to 63.36% (P=0.0001). The rates of uncomplicated vaginal delivery, forceps delivery and caesarian section over the two periods were 70.24, 12.76 and 17% versus 67.08, 14.41 and 18.51%, respectively: the differences were statistically significant. The indications for the use of forceps did not differ during the two periods. During vaginal delivery, the rate of forceps use as a function of EA administration/non-administration was remarkably constant over the two periods: 25.8% with EA versus 6.2% without EA in the first period compared with 24.9 and 6.2% in the second period. The forceps delivery rate was unaffected by the fact that EA was carried out by an anaesthetist specialised in obstetrics.

CONCLUSION

The addition of sufentanil to our protocol for EA has not altered the practice of instrumental extraction in our department. With EA, the rate of forceps delivery is multiplied by 4, irrespective of the protocol used.

A randomised clinical trial comparing the effects of delayed versus immediate pushing with epidural analgesia on mode of delivery and faecal continence

OBJECTIVE

To assess the effects of delayed vs immediate pushing in second stage of labour with epidural analgesia on delivery outcome, postpartum faecal continence and postpartum anal sphincter and pudendal nerve function.

DESIGN

Prospective, randomised, controlled trial.Tertiary referral maternity teaching hospital.

POPULATION

One hundred and seventy nulliparous women randomised at full dilatation to immediate or delayed pushing.

METHODS

A total of 178 nulliparous women, all with continuous epidural analgesia, were randomised at full cervical dilatation, but before the fetal head had reached the pelvic floor, to either immediate pushing or 1 hour delayed pushing. Labour outcome was analysed and all women underwent postpartum assessment of anal sphincter function, including anal manometry. Those women who had a normal delivery underwent neurophysiology studies, while those women who had an instrumental delivery underwent endoanal ultrasound.

MAIN OUTCOME MEASURES

Mode of delivery; altered faecal continence.

RESULTS

Ninety women were randomised to immediate pushing and 88 to delayed pushing. The spontaneous delivery rate was 56% (50/90) in the immediate pushing group and 52% (46/88) in the delayed pushing group. Mean duration of labour for the immediate pushing group was 427 minutes compared with 480 minutes for the delayed pushing group (P = 0.005). Eighty-four percent (76/90) of women in the immediate pushing group received oxytocin to augment labour, 21/76 (28%) in the second stage only. Eighty-one percent (71/88) of women in the delayed pushing group received oxytocin to augment labour, 22/71 (31%) in the second stage only. Fetal outcome did not differ between the two groups. Episiotomy rates were 73% and 69% in the immediate pushing and delayed pushing groups, respectively. 26% (23/90) of the immediate pushing group and 38% (33/88) of the delayed pushing group complained of altered faecal continence after delivery (NS). Manometry, ultrasound and neurophysiology studies did not differ significantly between the two groups. Overall, 55% of women after instrumental delivery had endosonographic evidence of damage to the external anal sphincter, while 36% of women after spontaneous delivery had abnormal neurophysiology studies.

CONCLUSIONS

Rates of instrumental delivery were similar following immediate and delayed pushing, in association with epidural analgesia. Delayed pushing prolonged labour by 1 hour but did not result in significantly higher rates of altered continence or anal sphincter injury, when compared with immediate pushing.

Bupivacaine 2.5 mg/ml versus bupivacaine 0.625 mg/ml and sufentanil l μg/ml with or without epinephrine 1 μg/ml for epidural analgesia in labour

We have compared three different methods of epidural analgesia in labour, bupivacaine 2.5 mg/ml (group B), bupivacaine 0.625 mg/ml + sufentanil 1 microg/ml (group BS) and bupivacaine 0.625 mg/ml + sufentanil 1 microg/ml + epinephrine 1 microg/ml (group BSE). One hundred and forty parturients with a singleton fetus with cephalic presentation were randomly allocated to one of the three groups. Group BSE had significantly less pain than groups B and BS. Group B had a significantly higher degree of motor blockade assessed on the Bromage scale. Significantly, more women in group B required urinary bladder catheterization than in the two other groups and they also had significantly less urge to push during active delivery. The incidence of mild pruritus was 18% in group BS and 36% in group BSE. The frequency of instrumental delivery and caesarean section was low (12% and 6.4%, respectively) with no significant differences between the groups. All women were highly satisfied with the method of analgesia and 97% would prefer the same kind of pain alleviation at the next delivery. We conclude that epidural analgesia with low-dose bupivacaine and sufentanil is as good an analgesic method as high-dose bupivacaine. Addition of low-dose epinephrine improves the analgesia.

Are women requiring unplanned intrapartum epidural analgesia different in a low-risk population?

We studied 645 full-term low-risk women in early labour in 6 units to evaluate the effects of maternal characteristics and obstetric management in early labour on the use of epidural analgesia, and to analyse the relationship between epidural analgesia, progress of labour and mode of delivery using multiple logistic regression. Among variables present in early labour, nulliparity, ethnicity and obstetric unit were the strongest predictors of epidural analgesia requirement. In nulliparous women, obstetric unit affected use of epidural analgesia (P<0.05) and induction of labour was associated with increased use of epidural analgesia (odds ratio 3.45, 95% CI: 1.45-7.90). In multiparous women, only ethnicity was statistically significant (P<0.05). Epidural analgesia was associated with longer labours and more instrumental deliveries (odds ratio 2.93, 95%CI: 1.48-5.83). In the epidural group, however, we found a positive correlation between first stage duration and elapsed time before epidural analgesia. Furthermore, rate of cervical dilation was similar in the non epidural group throughout the first stage (mean 3.41 cm/h, 95%CI: 3.19-3.63) and in the epidural group after epidural analgesia decision (mean 3.99, 95% CI: 2.96-5.02), while the mean cervical dilatation rate before epidural analgesia was 0.88 cm/h (95% CI: 0.72-1.04). The need for epidural analgesia is, therefore, multifactorial and difficult to predict. Whereas nulliparity increases epidural analgesia requirement, data on the progress of labour before pain relief suggest that epidural analgesia is a marker of pain severity and/or labour failure rather than the cause of delayed progress in low-risk pregnancies.

Neuraxial opioids in labour

Neuraxial opioids were first used for labour analgesia in 1980 following the description of spinal cord opioid receptors in 1979. Via these receptors in the dorsal horn, opioids modulate both the visceral and the somatic pain of labour. The onset and duration of action of the individual opioid are determined primarily by its relative lipid solubility. Neuraxial opioids have a local anaesthetic sparing effect, allowing the use of lower concentrations of both agents while maintaining analgesia. As a sole agent, intrathecal opioids can be used to provide analgesia during the first stage of labour, especially in the high-risk parturient. They also have a role in the management of perineal pain and the provision of rapid-onset analgesia. Unfortunately maternal and neonatal side-effects can occur, the most important being respiratory depression.

Obstetric outcome following epidural analgesia with bupivacaine-adrenaline 0.25% or bupivacaine 0.125% with sufentanil--a prospective randomized controlled study in 1000 parturients

BACKGROUND

Epidural analgesia (EDA) is the most efficient method for pain relief during labour, but there is still a debate as to whether it interferes with the normal process of delivery. Some authors argue that the incidence of instrumental deliveries, Caesarean section, malrotation and protracted labour is increased in parturients receiving EDA.

METHODS

1000 parturients were prospectively randomized to receive EDA either with a high dose of local anaesthetic (0.25% bupivacaine with adrenaline = HD) or with a low dose (0.125% bupivacaine with sufentanil 10 micrograms = LD).

RESULTS

The incidence of instrumental delivery and Caesarean section and the need for oxytocin was reduced in the LD compared to HD group. The delivery time was similar with HD and LD among primiparous, but decreased significantly among multiparous in the LD group. The incidence of malrotation was low in both groups. The quality of analgesia was equal during the first stage in the 2 groups, but was lower in the LD group during the second stage. More parturients in the LD group ambulated, but this did not affect the incidence of instrumental delivery.

CONCLUSION

It is concluded that a lower dosage of bupivacaine combined with sufentanil in epidural analgesia significantly improves the obstetric outcome as compared to a higher dosage of bupivacaine with adrenaline using intermittent bolus technique.

Comparison of 15 mg and 25 mg of bupivacaine both with 50 μg fentanyl as initial dose for epidural analgesia

Bupivacaine 15 mg is commonly used as a test dose prior to the initial dose for epidural analgesia in labour. When 15 mg or 25 mg of bupivacaine (15 ml of 0.1% or 0.167%) with 50 microg fentanyl was administered blindly to two groups of labouring women, as an initial dose, 83% and 90% of women respectively, achieved analgesia within 20 min. All the remaining women achieved analgesia with a further dose of 10 mg bupivacaine (10 m10.1%) with fentanyl 2 microg per ml given at 20 min.

Epidural analgesia in labor: an evaluation of risks and benefits

BACKGROUND

Intrapartum epidural analgesia has become increasingly popular because it is the most effective method of providing pain relief during labor. Much attention is given to its safety and efficacy, and many health care providers and consumers are unaware of its potential drawbacks. This article reviews the literature about the effects of epidural analgesia on the mother and infant.

METHODS

We performed a computer-assisted MEDLINE search for articles and a review of bibliographies from articles on epidural analgesia. When reported data were incomplete, authors were contacted for more detailed information.

RESULTS

The most common procedure-related complications, hypotension, inadvertent dural puncture, and headache, are easily treated and usually self-limited. Permanent morbidity and mortality are rare. Retrospective studies and randomized controlled trials both demonstrate that epidural analgesia is associated with increases in duration of labor, instrument vaginal delivery, and cesarean birth. To date only three trials randomized patients to narcotic versus epidural groups, and all showed a twofold to threefold increase in cesarean section for dystocia. Limiting epidural use in nulliparous labor and delaying its placement until after 5 cm of cervical dilation may reduce the risk of operative intervention for dystocia. Epidural analgesia may also increase intervention for fetal distress. Several studies show its association with maternal fever in labor. Its association with chronic back pain, neonatal behavioral changes, and maternal-infant bonding are more tenuous and require further study.

CONCLUSIONS

Epidural analgesia is a safe and effective method of relieving pain in labor, but is associated with longer labor, more operative intervention, and increases in cost. It must remain an option; however, caregivers and consumers should be aware of associated risks. Women should be counseled about these risks and other pain-relieving options before the duress of labor.

Obstetrical epidural anaesthesia in a rural Canadian hospital

Few rural hospitals offer obstetric epidural analgesia services and of those that do, there is a paucity of information about these anaesthetics. A retrospective review was conducted of all obstetrical epidurals from 1984-1988 in an 85-bed hospital in Saskatchewan to examine the indications, complications, and infant outcomes. During that period there were 1224 deliveries. From a total of 915 vaginal deliveries, 42 (4.6%) received an epidural. Caesarean sections numbered 309: 183 (59.3%) were with epidural analgesia of which 69 were urgent and 114 elective. The overall complication rate was 23% with the most important being hypotension (12%), dural punctures (1.8%), inadequate block requiring an intravenous supplement (4.0%) or a general anaesthetic (3.1%). Infant outcomes were favourable except for two unrelated intra-uterine deaths preceding labour.

Epidural bupivacaine dilution for labour. A comparison of three concentrations infused with a fixed dose of fentanyl

We have compared the effects of three epidural infusions in a randomised, double-blind study of 56 primigravid mothers in labour. An initial dose of bupivacaine 0.5% 8 ml was followed by infusion of either bupivacaine 0.125%, 0.062% or 0.031%. All solutions contained fentanyl 0.0002% and were run at 7.5 ml/hour. Women receiving the most dilute solution had significantly less analgesia (p less than 0.001) for the first 4 hours of the study, but pain scores were then similar for the three groups. No obvious benefit was gained by using very dilute bupivacaine.

Labour and delivery in mothers with asthma

In a retrospective study, the outcome of pregnancy and labour in 87 consecutively delivered asthmatic patients with singleton pregnancies was compared to that in a group of normal controls matched for maternal age and parity. Asthmatic patients had a higher incidence of low-birth-weight (less than 2500 g) babies, which was mainly found in those not requiring bronchodilator therapy. Bronchodilator therapy in asthmatic mothers was not associated with an increased incidence of preterm or post-term deliveries, low birth weight or big (greater than 90th centile) babies, induction of labour, instrumental deliveries, postpartum haemorrhage, or perinatal complications, when compared with asthmatic mothers not requiring treatment. The higher Caesarean section rate in the asthmatic mothers is mainly found in the group with bronchodilator therapy, and may be related to a slightly but not significantly higher rate of induction in these mothers. An increased rate of instrumental deliveries was found in asthmatic mothers, which is probably related to the use of epidural analgesia. The results indicate that asthma, if well controlled, does not significantly affect the outcome of pregnancy and labour.

Epidural fentanyl and perineal pain in labour

Perineal pain during the course of routine epidural analgesia with bupivacaine was treated with a 10-ml top-up of either bupivacaine 25 mg, fentanyl 100 micrograms or fentanyl 100 micrograms plus bupivacaine 10 mg, in 46 women in the first stage of labour. Only fentanyl plus bupivacaine produced consistently reliable analgesia which was quicker in onset and longer in duration (140, SD 26 minutes) than either fentanyl (114, SD 26 minutes) or bupivacaine (99, SD 44 minutes) alone. Side effects, itching and drowsiness, which were not troublesome, were more frequent in the groups given fentanyl.

Obstetrical epidural anaesthesia in a Canadian outpost hospital

The number of parturients receiving epidural anaesthesia in university medical centres is increasing. This trend is not paralleled in rural hospitals. Obstetrical epidural anaesthesia as provided in a 40-bed, remote hospital is reviewed for the ten-year period from January 1974 to December 1983. Charts were reviewed retrospectively for 116 patients undergoing epidural blockade. The indications, complication rates, as well as infant outcomes were noted. Seven per cent of all parturients received epidural anaesthetics. Ninety per cent of this group received systemic sedation or narcotics prior to epidural catheter insertion. Nineteen patients (16.3 per cent) experienced a major complication, including four dural punctures (3.4 per cent), ten episodes of significant hypotension (8.6 per cent), blood vessel puncture during catheter insertion in four patients (3.4 per cent), and transient paresthesia in one patient (0.8 per cent). Considerations for the provision of epidural anaesthesia in a remote hospital are discussed.

A comparative study of continuous and intermittent epidural analgesia for labour and delivery

This study compares a continuous infusion technique with intermittent "top-up" doses using 0.25 per cent bupivacaine for epidural analgesia for labour and delivery in healthy primiparous patients. Sixty women were randomized into two groups, A (continuous) and B (intermittent). Twenty-eight patients in Group A and 29 in Group B completed the study. We compared the groups with regard to satisfaction with pain relief for both labour and delivery as measured by a Visual Analogue Scale on five occasions during and after parturition. There was no difference between groups at any of the five stages. The difference in pain scores before the epidural and after the epidural was significant for both groups (p less than 0.001). The incidence of missed segments, degrees of motor block, height of sensory block, length of labour and fetal outcome were similar in both groups. Plasma bupivacaine levels were measured in six patients in each group. Mothers in Group A received more drug than those in Group B (p less than 0.01) but plasma bupivacaine levels remained low in the mother and the umbilical cord samples in the sub-set from this group. More women in Group A required outlet forceps (p less than 0.05) whereas mid-forceps and Caesarean section rates were similar in the two groups. Fewer mothers in the infusion group had spontaneous vaginal delivery. We conclude that infusion techniques are as effective as intermittent top-up epidurals and are well received by mothers in labour.

Continuous epidural infusion of 0.075% bupivacaine for pain relief in labour. A comparison with intermittent top-ups of 0.5% bupivacaine

Seventy-three women who requested epidural analgesia during labour were randomly allocated in a prospective study to receive either a continuous epidural infusion of 0.075% bupivacaine at a rate of 12-18 ml/hour (38 mothers) or intermittent top-ups of 0.5% bupivacaine (35 mothers). Both groups received an initial dose of 6-8 ml bupivacaine 0.5%. Patients were asked to score their pain using a 10-cm linear scale prior to insertion of the epidural, 30 minutes after its insertion and hourly thereafter. The quality of analgesia in the continuous infusion group was significantly better than in the intermittent top-up group (p less than 0.025). There was no significant difference in the total dose of bupivacaine given to the two groups.

Obstetrical anaesthesia at Winnipeg Women's Hospital 1975-83: anaesthetic techniques and complications

The obstetrical anaesthesia experience of the Winnipeg Women's Hospital from 1975 to 1983 was reviewed (n = 22,925 infants). Use of narcotics in labour for analgesia decreased from 38.7 to 18.3 per cent of the deliveries. For analgesia during spontaneous vaginal deliveries, epidural anaesthesia increased from 6.0 to 24.0 per cent, inhalational analgesia decreased from 53.7 to 3.2 per cent while "no anaesthetic intervention" rose from 40.3 to 72.8 per cent. Use of epidural anaesthesia for Caesarean section increased from 58.7 to 82.6 per cent. The most common acute complications of anaesthesia were hypotension and inadvertent dural puncture during epidural catheterization. The incidence of hypotension decreased from 28.3 to 17.4 per cent during the nine-year period. Dural puncture decreased from 4.7 to 1.1 per cent of all epidural administrations. Postpartum complaints (that were thought to be related to anaesthesia) were mainly headache, back pain and sore throat. The incidence of these complaints also decreased over the study period.

Effects of local anaesthetics on responses of human saphenous vein and bovine coronary artery to neurotransmitters, acetylcholine, noradrenaline and 5-hydroxytryptamine

The effects of 5 different local anaesthetics, lignocaine, etidocaine, prilocaine, mepivacaine, bupivacaine, and 3 different neurotransmitters, acetylcholine (ACh), noradrenaline (NA), 5-hydroxytryptamine (5-HT) on tone and contractility of human saphenous vein and bovine coronary artery were studied and compared in vitro. The experiments were carried out to see if there were species or tissue differences in the action of local anaesthetics and neurotransmitters at vascular smooth muscle, i.e. saphenous vein and coronary artery. Another important aspect was to see if local anaesthetics modified cholinergic (ACh), adrenergic (NA) and serotoninergic (5-HT) responses in vascular smooth muscle. Among the local anaesthetics studied, lignocaine and etidocaine produced prolonged relaxations, whereas prilocaine, mepivacaine, bupivacaine produced contractions in the saphenous vein and coronary artery. High concentrations of the latter drugs produced relaxations in the blood vessels. Among the local anaesthetics, lignocaine produced differential effects on saphenous vein and coronary artery, its effect on the latter was 3 times larger than on the saphenous vein. ACh, NA and 5-HT contracted the saphenous vein. In the coronary artery, ACh and 5-HT contracted whereas NA relaxed the vessel. On a molar basis, ACh was less effective than NA in contracting the saphenous vein. 5-HT was equipotent on both the saphenous vein and coronary artery. Lignocaine reduced ACh, NA and 5-HT-induced contractions in the saphenous vein and those of ACh and 5-HT in the coronary artery, and shifted the control curves, non-competitively, to the right. The relaxation produced by NA in the coronary artery was enhanced by lignocaine.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidural fentanyl in labour. An evaluation of the systemic contribution to analgesia

In a randomized double-blind trial in the first stage of labour, 20 patients given fentanyl 80 micrograms in the epidural test dose of bupivacaine, were compared with 20 patients receiving an intravenous infusion designed to produce comparable plasma fentanyl concentrations, at the same time as their epidural test dose. Despite slightly higher plasma fentanyl concentrations in the intravenous fentanyl group, epidural fentanyl produced analgesia which was more complete, more rapid in onset and slightly longer lasting. Supplementary doses of bupivacaine were needed to produce analgesia in 75% of the intravenous and 30% of the epidural fentanyl group. It is clear that epidural fentanyl produces satisfactory pain relief when added to the epidural test dose, but that the presence of fentanyl in the systemic circulation makes a negligible contribution to analgesia.