Recent advances in patient-controlled epidural analgesia for labour

Uterine and Abdominal Muscle Electromyographic Activities in Control and PCEA-Treated Nulliparous Women During the Second Stage of Labor

OBJECTIVE

Patient-controlled epidural analgesia (PCEA), used to relieve pain during delivery, delays labor but the mechanism is unknown. The aim was to investigate the effects of PCEA on uterine and abdominal muscles electromyographic (EMG) activity during the second stage of labor.

METHODS

This study included 45 nulliparous pregnant women without PCEA, 42 women with standard PCEA treatment given during the first stage of labor and stopped near the end of the first stage, and 22 women with standard PCEA treatment with continued use throughout the first and second stages of labor. The EMG signals were recorded from the abdominal surface using PowerLab hardware and LabChart software (ADInstruments, New South Wales, Australia) and filtered to separate uterine and abdominal EMG. Various EMG burst parameters were obtained.

RESULTS

There are no differences ( P > .05) in the age, body mass index, fetal weight, and Apgar scores between the patients from the various groups. PCEA (both stopped and continued) inhibits ( P < .05) duration, number of bursts, and root mean square of uterine EMG. PCEA also produces statistically significant ( P < .001) reductions in abdominal EMG. The decrease in EMG activity is accompanied by a significant ( P < .001) prolongation of the second stage duration (PCEA continued = 95.08 ± 8.60 minutes, PCEA stopped = 79.39 ± 6.25 minutes, no PCEA = 61.00 ± 7.23 minutes).

CONCLUSION

PCEA suppresses uterine and abdominal muscle EMG during the second stage of labor but inhibition depends upon the treatment schedule. PCEA prolongs the duration of labor by inhibition of uterine and abdominal muscle and neural activity.

Pain management for women in labour: an overview of systematic reviews

BACKGROUND

The pain that women experience during labour is affected by multiple physiological and psychosocial factors and its intensity can vary greatly.  Most women in labour require pain relief. Pain management strategies include non-pharmacological interventions (that aim to help women cope with pain in labour) and pharmacological interventions (that aim to relieve the pain of labour).

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on the efficacy and safety of non-pharmacological and pharmacological interventions to manage pain in labour. We considered findings from non-Cochrane systematic reviews if there was no relevant Cochrane review.

METHODS

We searched the Cochrane Database of Systematic Reviews (The Cochrane Library 2011, Issue 5), The Cochrane Database of Abstracts of Reviews of Effects (The Cochrane Library 2011, Issue 2 of 4), MEDLINE (1966 to 31 May 2011) and EMBASE (1974 to 31 May 2011) to identify all relevant systematic reviews of randomised controlled trials of pain management in labour. Each of the contributing Cochrane reviews (nine new, six updated) followed a generic protocol with 13 common primary efficacy and safety outcomes. Each Cochrane review included comparisons with placebo, standard care or with a different intervention according to a predefined hierarchy of interventions. Two review authors extracted data and assessed methodological quality, and data were checked by a third author. This overview is a narrative summary of the results obtained from individual reviews.

MAIN RESULTS

We identified 15 Cochrane reviews (255 included trials) and three non-Cochrane reviews (55 included trials) for inclusion within this overview. For all interventions, with available data, results are presented as comparisons of: 1. Intervention versus placebo or standard care; 2. Different forms of the same intervention (e.g. one opioid versus another opioid); 3. One type of intervention versus a different type of intervention (e.g. TENS versus opioid). Not all reviews included results for all comparisons. Most reviews compared the intervention with placebo or standard care, but with the exception of opioids and epidural analgesia, there were few direct comparisons between different forms of the same intervention, and even fewer comparisons between different interventions. Based on these three comparisons, we have categorised interventions into: " What works" ,"What may work", and "Insufficient evidence to make a judgement".WHAT WORKSEvidence suggests that epidural, combined spinal epidural (CSE) and inhaled analgesia effectively manage pain in labour, but may give rise to adverse effects. Epidural, and inhaled analgesia effectively relieve pain when compared with placebo or a different type of intervention (epidural versus opioids). Combined-spinal epidurals relieve pain more quickly than traditional or low dose epidurals. Women receiving inhaled analgesia were more likely to experience vomiting, nausea and dizziness.When compared with placebo or opioids, women receiving epidural analgesia had more instrumental vaginal births and caesarean sections for fetal distress, although there was no difference in the rates of caesarean section overall. Women receiving epidural analgesia were more likely to experience hypotension, motor blockade, fever or urinary retention. Less urinary retention was observed in women receiving CSE than in women receiving traditional epidurals. More women receiving CSE than low-dose epidural experienced pruritus.  WHAT MAY WORKThere is some evidence to suggest that immersion in water, relaxation, acupuncture, massage and local anaesthetic nerve blocks or non-opioid drugs may improve management of labour pain, with few adverse effects.  Evidence was mainly limited to single trials. These interventions relieved pain and improved satisfaction with pain relief (immersion, relaxation, acupuncture, local anaesthetic nerve blocks, non-opioids) and childbirth experience (immersion, relaxation, non-opioids) when compared with placebo or standard care. Relaxation was associated with fewer assisted vaginal births and acupuncture was associated with fewer assisted vaginal births and caesarean sections.INSUFFICIENT EVIDENCEThere is insufficient evidence to make judgements on whether or not hypnosis, biofeedback, sterile water injection, aromatherapy, TENS, or parenteral opioids are more effective than placebo or other interventions for pain management in labour. In comparison with other opioids more women receiving pethidine experienced adverse effects including drowsiness and nausea. 

AUTHORS' CONCLUSIONS

Most methods of non-pharmacological pain management are non-invasive and appear to be safe for mother and baby, however, their efficacy is unclear, due to limited high quality evidence. In many reviews, only one or two trials provided outcome data for analysis and the overall methodological quality of the trials was low. High quality trials are needed.There is more evidence to support the efficacy of pharmacological methods, but these have more adverse effects. Thus, epidural analgesia provides effective pain relief but at the cost of increased instrumental vaginal birth.It remains important to tailor methods used to each woman's wishes, needs and circumstances, such as anticipated duration of labour, the infant's condition, and any augmentation or induction of labour.A major challenge in compiling this overview, and the individual systematic reviews on which it is based, has been the variation in use of different process and outcome measures in different trials, particularly assessment of pain and its relief, and effects on the neonate after birth. This made it difficult to pool results from otherwise similar studies, and to derive conclusions from the totality of evidence. Other important outcomes have simply not been assessed in trials; thus, despite concerns for 30 years or more about the effects of maternal opioid administration during labour on subsequent neonatal behaviour and its influence on breastfeeding, only two out of 57 trials of opioids reported breastfeeding as an outcome. We therefore strongly recommend that the outcome measures, agreed through wide consultation for this project, are used in all future trials of methods of pain management.

Low Dose Epidural Analgesia During Labor: Comparison Between Patient Controlled Epidural Analgesia with Basal Continuous Infusion and Intermittent Bolus Technique

OBJECTIVES

To compare the efficacy and safety of patient controlled epidural analgesia with basal continuous infusion versus intermittent bolus for labor analgesia using fentanyl and bupivacaine.

METHODS

In this prospective study, 60 parturients having singleton term uncomplicated pregnancy in early active labor were included. 30 parturients were allocated to receive patient controlled epidural analgesia + basal continuous infusion (Group-A) and 30 received intermittent bolus on demand (Group-B). Efficacy of technique was assessed in terms of quality of analgesia on 0-10 cm verbal analogue scale. Effect on labor was assessed by duration of labor, mode of delivery, and parturient's satisfaction. Neonatal outcome was measured by Apgar score. Data were expressed as mean ± SD and analysed using Student 't' test and chi square test where appropriate. P < 0.05 was considered statistically significant.

RESULTS

Analgesic efficacy of both the groups was comparable. Maternal satisfaction was better in group A than in group B but the results did not achieve statistical significance. Effect on labor and neonatal outcome were comparable.

CONCLUSIONS

Both the techniques appear to be safe for the mother and neonate with excellent analgesic efficacy. In a busy obstetric unit with increased demand of epidural analgesia, patient controlled epidural analgesia with basal continuous infusion may be preferred.

Obstetric outcomes and maternal satisfaction in nulliparous women using patient-controlled epidural analgesia

OBJECTIVE

The purpose of this study was to compare obstetric outcomes and maternal satisfaction in nulliparous women in spontaneous labor who used patient-controlled epidural analgesia (PCEA) vs continuous epidural infusion (CEI).

STUDY DESIGN

We conducted a double-masked trial of 270 nulliparous women who were assigned randomly to 3 groups (with a concentration 0.1% bupivacaine and 2 μg/mL fentanyl): group I, CEI-only (10 mL/h); group II, CEI + PCEA (CEI 10 mL/h plus PCEA 10 mL, at 20 minutes); group III, PCEA-only (10 mL, at 20 minutes). A PCEA bolus button was given to each subject. The primary outcome was the dosage of local anesthetic that was used.

RESULTS

The total milligrams of bupivacaine that were used was less in the PCEA-only group compared with CEI: group I. 74.8 ± 36 mg; group II, 97.3 ± 53 mg; group III, 52.4 ± 42 mg (P < .001). Pain with pushing, however, was worse in the PCEA-only group. Median satisfaction scores were similar (scale, 0 [best] to 100 [worst]: group I, 0; group II, 0; group III, 0 (P = .23).

CONCLUSION

PCEA results in less anesthetic used, and maternal satisfaction remains high without a continuous infusion. Pain with pushing, however, was worse with the PCEA alone.

Comparison of intermittent and continuous epidural analgesia on delivery and progression of labour

In this study, 205 nulliparous parturients were enrolled to receive either intermittent (n = 101) or continuous (n = 104) type of epidural analgesia in labour. The primary outcome was rate of caesarean deliveries, whereas secondary outcomes included rate of fundal pressure manoeuvres, duration of labour from application of analgesia, dose of anaesthetic and short-term maternal and neonatal outcome between two groups. Rate of caesarean deliveries was significantly increased in the continuous group (15/104 vs 5/101, p = 0.02), as well as rate of fundal pressure manoeuvres (24/104 vs 11/101, p = 0.02) and dose of fentanyl (100 [100-300] vs 187.5 [125-450] μg, p < 0.001 and levobupivacaine (40 [40-60] vs 75 [50-90] ml, p < 0.001). Duration of labour from analgesia to delivery was not significantly different between the two groups (414 ± 101 vs 432 ± 94 min, p = 0.12).

A double-blind randomized controlled trial of patient-controlled epidural analgesia with or without a background infusion following initial spinal analgesia for labor pain

BACKGROUND

Patient-controlled epidural analgesia (PCEA) combined with spinal analgesia is an option for pain relief in labor. However, the effect of a CBI on the analgesic requirements of laboring women is still debated. This double-blind study investigated the effect of CBI with PCEA following spinal analgesia on the local anesthetic requirements of parturients during labor.

METHODS

Sixty-six nulliparous women were randomly assigned to a standard PCEA protocol (5-mL demand bolus, 10-min lockout) with or without a CBI of 6 mL/h. The epidural solution consisted of 0.1% ropivacaine with fentanyl 2 microg/mL. Labor analgesia was initiated in both groups with intrathecal bupivacaine 2.5 mg plus fentanyl 25 microg. The number of demands per hour and the hourly dose of ropivacaine were calculated for both groups.

RESULTS

The median [range] number of analgesic boluses per hour in the PCEA group that were demanded: 2.4 [0.8-12.2] and delivered: 1.6 [0.8-2.6], were significantly greater than those in the PCEA+CBI group: 0.7 [0.4-4.2] and 0.6 [0.2-1.3] (P 0.05). However, the hourly ropivacaine dose in the PCEA group (7.9 [3.9-13.2] mg/h) was not significantly different from that in the PCEA+CBI group (8.4 [6.0-12.5] mg/h).

CONCLUSION

In laboring nulliparous patients provided initial labor analgesia with spinal anesthesia, the use of a continuous background infusion decreases PCEA demand dosing, but not the total hourly amount of ropivacaine and fentanyl used.

Epidural Labor Analgesia: Continuous Infusion Versus Patient-Controlled Epidural Analgesia With Background Infusion Versus Without a Background Infusion

The purpose of this study was to compare the total epidural dose of 3 commonly used labor epidural modalities. After local institutional review board approval, 195 laboring parturients received an epidural catheter for labor analgesia. All patients received an initial bolus of 0.1% ropivacaine (10 mL) and fentanyl (100 microg). Maintenance of labor analgesia consisted of ropivacaine 0.1% with fentanyl 2 microg/mL. Patients were then randomly assigned into 3 groups: Group 1 (continuous epidural infusion [CEI]), continuous infusion at 10 mL/h; group 2 (CEI + patient-controlled epidural analgesia [PCEA]), CEI at 5 mL/h with a demand dose of 5 mL allowed every 20 minutes with a 20 mL/h maximum dose; group 3 (PCEA), demand doses only of 5 mL every 15 minutes with a 20 mL/h maximum dose. Measured variables included total epidural dose, total bolus requests and boluses delivered, number of staff interventions, pain Visual Analog Scale (VAS; 0-100), modified Bromage scores, stage I and II labor duration, delivery outcome, and maternal satisfaction after delivery. No differences were noted with respect to pain VAS, modified Bromage scores, stage I and II labor duration, number of staff interventions, delivery outcome, and maternal satisfaction score. Total infusion dose was lower in demand dose only PCEA compared with CEI and CEI + PCEA groups (P = < .01). Demand dose-only PCEA results in less total epidural dose compared with CEI and CEI + PCEA without affecting labor duration, motor block, pain VAS, maternal and neonatal outcomes, and maternal satisfaction.

PERSPECTIVE

This article compares 3 commonly used labor epidural delivery modalities (traditional continuous epidural infusion, patient-controlled epidural analgesia with a background infusion, and demand dose-only patient-controlled epidural analgesia). Benefits in epidural dose reduction with demand dose only PCEA does not translate into improved maternal and neonatal outcome.