Patient-controlled epidural analgesia or continuous infusion: advantages and disadvantages of different modes of delivering epidural analgesia for labour

Patient-controlled epidural analgesia, intermittent top-up and continuous infusion are equally effective in providing epidural pain relief during labour. Patient-controlled epidural analgesia is associated with a significant reduction in hourly dose requirements when compared with continuous infusion, and by transferring the responsibility for epidural top-up, it offers the parturient the psychological benefit of being in control. For these reasons, patient-controlled epidural analgesia may become the method of choice for epidural pain relief during labour. However, the safety of the method needs to be documented more extensively, and the advantage of a reduction in hourly dose requirements needs to be visualized in terms of an improvement in labour or neonatal outcome. Moreover, the optimal dose, drug combination and settings still remain to be determined.     

Continuous epidural infusion of 0.075% bupivacaine for pain relief in labour

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.     

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 pritniparous 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 < 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 < 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 < 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.     

An epidural infusion technique for labour

A regimen to facilitate control of epidural infusions in labour has been developed which allows midwives to alter infusion rates to maintain satisfactory analgesia. The technique was used successfully in 30 patients and, in a prospective study, was compared with women who received conventional top-up epidurals. It was found that infusions provided comparable analgesia and decreased midwife workload but resulted in a higher dosage of bupivacaine.     

Continuous infusion epidural analgesia in obstetrics

The effects of 0.08% (Group A) and 0.25% (Group B) solutions of bupivacaine were compared in a random manner, to assess continuous pump infusion epidural analgesia in labour. Both solutions were infused at a dose rate of 20 mg bupivacaine/hour. The results in all the mothers who had received infusions lasting more than 4 hours were studied. There were 25 in Group A and 28 in Group B. Any treatment during the infusion epidural for inadequate analgesia, hypotension, etc., was recorded as an intervention. The mean of the intervention-free intervals was significantly greater in Group A than in Group B, and significantly fewer top-up injections were required in Group A. The results show that the administration of a 0.08% solution of bupivacaine into the epidural space by continuous pump infusion is more labour saving than the infusion of a 0.25% solution. The concept that a greater volume infusion rate maintains a more extended liquid sleeve of local anaesthetic in the epidural space is supported.     

Comparison of continuous infusion versus midwife administered top-ups of epidural bupivacaine for labour analgesia: effect on second stage of labour and mode of delivery

Using a population-based study we retrospectively compared the effect of continuous versus intermittent top-up epidural analgesia on the outcome of labour at the University Hospital of Wales. We analysed the labour outcome of 410 primigravid deliveries over an 18-month period during a change in delivery suite protocol. Data were retrieved from the Cardiff Births Survey and the sample was analysed in two groups: group 1 (n = 201) received a continuous infusion of 0.1% bupivacaine plus fentanyl 2 microg/mL and group 2 (n = 209) received intermittent top-ups of the same solution. Outcome measures were the number of operative deliveries and the proportion of those deliveries that were due to prolongation of the second stage of labour. There were no significant differences in terms of group characteristics, women undergoing assisted vaginal delivery (group 1: 83 vs. group 2: 70, OR 0.8 CI 0.5-1.2), caesarean section (group 1: 59 vs. group 2: 61, OR 1.0 CI 0.6-1.5), and women with prolonged second stage (group 1: 50 vs. group 2: 47, OR 1.1 CI 0.6-1.8). The presumed reduction in motor blockade associated with intermittent top-up epidural regimes did not affect the outcome of labour.     

Programmed intermittent epidural bolus vs. patient-controlled epidural analgesia for maintenance of labour analgesia: a two-centre,double-blind,randomised study†

The programmed intermittent epidural bolus technique has shown superiority to continuous epidural infusion techniques, with or without patient-controlled epidural analgesia for pain relief, reduced motor block and patient satisfaction. Many institutions still use patient-controlled epidural analgesia without a background infusion, and a comparative study between programmed intermittent epidural bolus and patient-controlled epidural analgesia without a background infusion has not yet been performed. We performed a randomised, two-centre, double-blind, controlled trial of these two techniques. The primary outcome was the incidence of breakthrough pain requiring a top-up dose by an anaesthetist. Secondary outcomes included: motor block; pain scores; patient satisfaction; local anaesthetic consumption; and obstetric and neonatal outcomes. We recruited 130 nulliparous women who received initial spinal analgesia, and then epidural analgesia was initiated and maintained with either programmed intermittent epidural bolus or patient-controlled epidural analgesia using ropivacaine 0.12% with sufentanil 0.75 µg·ml^-1. The programmed intermittent epidural bolus group had a programmed bolus of 10 ml every hour, with on-demand patient-controlled epidural analgesia boluses of 5 ml with a 20 min lockout, and the patient-controlled epidural analgesia group had a 5 ml bolus with a 12 min lockout interval; the potential maximum volume per hour was the same in both groups. The patients in the programmed intermittent epidural bolus group had less frequent breakthrough pain compared with the patient-controlled epidural analgesia group, 7 (10.9%) vs. 38 (62.3%; p < 0.0001), respectively. There was a significant difference in motor block (modified Bromage score ≤ 4) frequency between groups, programmed intermittent epidural bolus group 1 (1.6%) vs. patient-controlled epidural analgesia group 8 (13.1%); p = 0.015. The programmed intermittent epidural bolus group had greater local anaesthetic consumption with fewer patient-controlled epidural analgesia boluses. Patient satisfaction scores and obstetric or neonatal outcomes were not different between groups. In conclusion, we found that a programmed intermittent epidural bolus technique using 10 ml programmed boluses and 5 ml patient-controlled epidural analgesia boluses was superior to a patient-controlled epidural analgesia technique using 5 ml boluses and no background infusion.     

Automated regular boluses for epidural analgesia: a comparison with continuous infusion

BACKGROUND: Intermittent epidural bolus dosing is a method of drug delivery that can prolong the duration of labour analgesia induced by a combined spinal epidural (CSE). In this randomized, double-blinded study, we compared the analgesic efficacy of two drug delivery systems: regular intermittent epidural boluses and continuous epidural infusion and assessed the incidence of breakthrough pain after CSE. METHODS: With the approval of the Hospital Ethics Committee, we recruited 60 parturients into this randomized controlled trial. A CSE was performed with intrathecal fentanyl 25 mug in all patients. The parturients were then randomly allocated into two groups. The infusion group received a continuous epidural infusion of levobupivacaine 0.1% with fentanyl 2 microg/mL at a rate of 10 mL/h. The bolus group received 5-mL epidural boluses every half hour. The sample size was computed to detect a 40% reduction in the rate of breakthrough pain. RESULTS: The bolus group had a lower incidence of breakthrough pain than the infusion group (10% vs. 37%, P < 0.05). The bolus group also had significantly higher satisfaction scores for labour analgesia: 97+/-8 (mean+/-SD) vs. 89+/-7 (P < 0.05). CONCLUSION: Automated regular bolus delivery of epidural analgesia when compared with continuous infusion decreased the incidence of breakthrough pain and increased maternal satisfaction. In a busy obstetric unit, this may also serve to decrease the anesthetists' workload.     

A survey of epidural analgesia for labour in the United Kingdom

A postal survey of obstetric units throughout the UK was conducted to obtain information about the provision of epidural analgesia for labour. Ninety per cent of units offered a 24-h epidural service and the average epidural rate was 24%. The most commonly administered epidural test dose was 3 ml of bupivacaine 0.5% and bupivacaine 0. 25% was most often used as the initial epidural top-up. Continuous infusions of low-dose bupivacaine and opioid mixtures were the most popular method of maintenance epidural analgesia. Twenty-four per cent of units offered combined spinal-epidural analgesia in addition to standard epidural analgesia. Midwives played a prominent role in the administration of epidural bolus top-ups and also in the assessment and maintenance of continuous epidural infusions.     

Impact study of the introduction of low-dose epidural (bupivacaine 0.1%/fentanyl 2 microg . mL(-1)) compared with bupivacaine 0.25% for labour analgesia

We conducted a retrospective analysis of the obstetric effects of introducing a low-dose epidural regimen for epidural analgesia in labour. Before this, all women in our unit requesting epidural analgesia for labour received intermittent boluses (10 mL) of 0.25% bupivacaine. After the introduction of the low-dose service in March 2000, intermittent boluses (10 mL) of 0.1% bupivacaine with fentanyl 2 microg . mL(-1) were given. The records of 300 women were examined, 150 who had received the standard regimen before the introduction of the new service and 150 women afterwards. The groups were compared for outcome of labour, quality of analgesia and any adverse events related to the epidural analgesia. There was a significant reduction in the low-dose group in the number of women requiring instrumental delivery (41% vs. 29%, P = 0.04). The need for indwelling bladder catheters was also reduced in the patients receiving the low-dose regimen (21.3% vs. 4.7%, P < 0.001). Duration of analgesia was longer in patients receiving bupivacaine 0.25% (mean minimum time between boluses 42.25 +/- 33.8 vs. 24.37 +/- 19.8 min, P < 0.001). The need for further anaesthetic intervention was higher with the low-dose regimen (24% vs. 34%, P = 0.037). Maternal satisfaction was high in both groups (95 and 97%, respectively). We conclude that the introduction of a low-dose regimen of epidural analgesia for labour reduces the incidence of instrumental deliveries. It also decreases the incidence of bladder catheterisation during labour, but the need for anaesthetic intervention may be greater.     

Epidural analgesia for major neonatal surgery

Safe effective analgesia for neonates undergoing major surgery remains a challenge particularly in institutions where resources are limited. The experience in the use of epidural analgesia in 240 neonates weighing between 0.9–5.8 kg body weight (lumbar n=211, thoracic n=29) is reviewed. Dural puncture (n=1), convulsion(r)(n=1) and intravascular migration of catheter (n=1) were the only complications. In all cases effective analgesia was established intraoperatively. Postoperatively analgesia was maintained by intermittent ‘top-ups’ (n=170) and continuous infusion (n=10). Skin epidural distance ranged between 3 and 12 mm (mean 6.0±1.7 mm) and did not correlate with the patients’ weight. Patients remained haemodynamically stable except occasional bradycardia below 100 (n=15) which was successfully managed with anticholinergics. The potential risks and benefits of epidural analgesia in this age group are discussed and arguments for intermittent ‘top-up’ doses rather than continuous infusions presented.     

Epidural analgesia-anaesthesia in obstetrics

Epidural analgesia is the most effective and innocuous technique for obstetrics. Pain relief is its main indication but maternal diseases that might be decompensated by labour and delivery are also accepted indications. Low doses of long-acting local anaesthetics alone or in combination with low doses of fentanyl or sufentanil provide good quality analgesia and are safe for mother and fetus. Test doses in parturients lack sufficient specificity and sensitivity for detecting inadvertent intravascular injection, and subarachnoid migration of the catheter is possible at any time during the procedure. Therefore, every injection must be considered as a test dose and only fractionated injections must be made. Epidural block to T10 is needed for labour and to level T4 for Caesarean section. Maintenance of the block with a continuous infusion, or patient-controlled epidural analgesia with a background continuous infusion, provides more stable analgesia than by intermittent injection. Technical difficulties, dural tap, bloody tap, hypotension and insufficient block are most frequent complications of epidural block in obstetrics. Excessive motor block prolongs the second stage of labour and increases the frequency for instrumental delivery and is therefore considered a complication.     

A comparison of methods of post-operative analgesia in children undergoing limb reconstruction with circular frames

This retrospective study compared post-operative epidural analgesia (E), continuous peripheral nerve blocks (CPNB) and morphine infusion (M) in 68 children undergoing limb reconstruction with circular frames. The data collected included episodes of severe pain, post-operative duration of analgesia, requirement for top-up analgesia, number of osteotomies, side effects and complications. There was a significant difference between the number of episodes of severe pain in patients receiving a morphine infusion and those receiving epidurals or CPNB (M vs E, p < 0.0001; M vs CPNB, p = 0.018). The CPNB group was associated with the lowest incidence of episodes of severe pain and top-up analgesia. Epidural analgesia was associated with significantly more nausea and vomiting than morphine infusion (p = 0.053) and CPNB (p = 0.023). It also had a significantly higher incidence of motor blockade than CPNB (p < 0.01). We found that the most effective method of post-operative analgesia for children undergoing lower limb reconstruction was sciatic nerve catheterisation and continuous infusion.     

Determination of the optimal programmed intermittent epidural bolus volume of bupivacaine 0.0625% with fentanyl 2 μg.ml−1 at a fixed interval of forty minutes: a biased coin up‐and‐down sequential allocation trial

The optimum time interval for 10 ml boluses of bupivacaine 0.0625% + fentanyl 2 μg.ml^?1 as part of a programmed intermittent epidural bolus regimen has been found to be 40 min. This regimen was shown to be effective without the use of supplementary patient‐controlled epidural analgesia boluses in 90% of women during the first stage of labour, although with a rate of sensory block to ice above T6 in 34% of women. We aimed to determine the optimum programmed intermittent epidural bolus volume at a 40 min interval to provide effective analgesia in 90% of women (EV₉₀) during the first stage of labour, without the use of patient‐controlled epidural analgesia. We performed a prospective double‐blind dose‐finding study using the biased coin up‐and‐down sequential allocation method in 40 women. The estimated EV₉₀ was 11.0 (95%CI 10.0–11.7) ml with the isotonic regression method and 10.7 (95%CI 10.3–11.0) ml with the truncated Dixon and Mood method. Overall, 18 women had a sensory block above T6, and 37 women exhibited no motor block. No women required treatment for hypotension. In conclusion, it is not possible to reduce the programmed intermittent epidural bolus volume from 10 ml, used in our current regimen, without compromising the quality of analgesia. Using this regimen, a high proportion of women will develop a sensory block above T6.     

Postoperative pain relief and regional techniques

The methods of providing postoperative analgesia by regional anaesthetic techniques with local anaesthetics are outlined. For the use of epidural analgesia, the techniques of inserting an epidural catheter at any level of the spine must be familiar. The block should be regional, restricted to the area of pain and effective at all times after its institution with a minimum of side effects. Bupivacaine is at present the best local anaesthetic and can be administered either as intermittent injections with an interval of 1-2 hours or as a continuous infusion. A dose regimen for thoracic, abdominal, perineal and lower extremity pain is presented. Side effects of the epidural technique and ways to treat and avoid them are discussed. The intercostal nerve block for post-thoracotomy and upper abdominal pain is described with special reference to the recent development of the continuous technique with bupivacaine and the cryoanalgesia technique.     

Is opioid loading necessary before opioid/local anaesthetic epidural infusion? A randomized double-blind study in labour

The effects of two different epidural loading doses administered before starting an opioid/low dose local anaesthetic infusion were examined in a randomized double-blind study during labour. Forty mothers were given either 10 ml 0.25% plain bupivacaine or 10 ml 0.125% plain bupivacaine containing 5 mcg of sufentanil followed in all cases by epidural infusion of 0.08% plain bupivacaine containing 0.2 mcg/ml of sufentanil, which was continued into the second stage. The quality of analgesia did not differ significantly between the groups in either the first or the second stage of labour: in each group 75% of women required 0 or 1 top-up during labour and verbal numerical pain scores were similar. Over 80% of women in each group reported a pain free second stage of labour. There were no differences in the mode of delivery between the groups with 60% of women in each group having a spontaneous vaginal delivery. The proportion of women with motor block increased with the duration of the epidural infusion, with no difference between the groups. There was no difference in the degree of maternal satisfaction assessed 24 hours after delivery, with 80% of women in each group awarding the maximum verbal numerical score for their satisfaction with epidural analgesia. The incidence of maternal side effects (nausea, vomiting, drowsiness and pruritus) was similar in the 2 groups as was neonatal outcome, assessed by Apgar and neurological and adaptive capacity scores and umbilical artery and vein pH. We conclude that opioid loading before opioid/low-dose bupivacaine epidural infusions is unnecessary.     

High-volume patient-controlled epidural vs. programmed intermittent epidural bolus for labour analgesia: a randomised controlled study

The aim of neuraxial analgesia is to achieve excellent pain relief with the fewest adverse effects. The most recently introduced technique for epidural analgesia maintenance is the programmed intermittent epidural bolus. In a recent study, we compared this with patient-controlled epidural analgesia without a background infusion and found that a programmed intermittent epidural bolus was associated with less breakthrough pain, lower pain scores, higher local anaesthetic consumption and comparable motor block. However, we had compared 10 ml programmed intermittent epidural boluses with 5 ml patient-controlled epidural analgesia boluses. To overcome this potential limitation, we designed a randomised, multicentre non-inferiority trial using 10 ml boluses in each group. The primary outcome was the incidence of breakthrough pain and total analgesic intake. Secondary outcomes included motor block; pain scores; patient satisfaction; and obstetric and neonatal outcomes. The trial was considered positive if two endpoints were met: non-inferiority of patient-controlled epidural analgesia with respect to breakthrough pain; and superiority of patient-controlled epidural analgesia with respect to local anaesthetic consumption. A total of 360 nulliparous women were allocated randomly to patient-controlled epidural analgesia-only or programmed intermittent epidural bolus groups. The patient-controlled group received 10 ml boluses of ropivacaine 0.12% with sufentanil 0.75 μg.ml^-1; the programmed intermittent group received 10 ml boluses supplemented by 5 ml patient-controlled boluses. The lockout period was 30 min in each group and the maximum allowed hourly local anaesthetic/opioid consumption was identical between the groups. Breakthrough pain was similar between groups (11.2% patient controlled vs. 10.8% programmed intermittent, p = 0.003 for non-inferiority). Total ropivacaine consumption was lower in the PCEA–group (mean difference 15.3 mg, p < 0.001). Motor block, patient satisfaction scores and maternal and neonatal outcomes were similar across both groups. In conclusion, patient-controlled epidural analgesia is non-inferior to programmed intermittent epidural bolus if equal volumes of patient-controlled epidural analgesia are used to maintain labour analgesia and superior with respect to local anaesthetic consumption.     

Epidural analgesia for painless delivery. Our experience

BACKGROUND: We know that a stress condition causes hormonal responses (cortisol, prolactin, TSH, ACTH, catecholamines, beta-endorphines). This hormonal "storm" causes metabolic and haemodynamic changes that can get worse postoperative outcome as well as birth. Analgesia for labour is an anesthesiological procedure which spreading in Italy resulted very difficult, for instance, especially in southern Italy, "old popular believes" (such as paralysis risk after lumbar puncture, Post-Dural Puncture Headache (PDPH) and the confusion between epidural and subdural anesthesia). METHODS: In front of these problems we report our experience in this field. Experimental plan: in our retrospective study we examined painless labour cases and we compared them with natural labour cases without analgesia. Environment: women of this study were pregnant admitted in obstetrics department of our hospital at the end of pregnancy. Patients: pregnant women who wanted epidural analgesia were 50 (group A); data group A were compared with data of 50 pregnant women who refused analgesia (group B). Technique: beginning labour, when cervical dilatation was 3 cm and foetal head was going down we performed epidural puncture and positioned, catheter in epidural space giving opiate and local anesthetic drugs using "top-up" method. Data: we compared APGAR-score after birth and the judgement expressed by women of the two groups. RESULTS AND CONCLUSIONS: APGAR-score in new-borns with epidural analgesia in higher than new-born without epidural analgesia; furthermore, patients who choose painless labour expressed a better judgement than women who refused epidural analgesia.     

Efficacy of postoperative patient-controlled and continuous infusion epidural analgesia versus intravenous patient-controlled analgesia with opioids: a meta-analysis

The authors performed a meta-analysis and found that epidural analgesia overall provided superior postoperative analgesia compared with intravenous patient-controlled analgesia. For all types of surgery and pain assessments, all forms of epidural analgesia (both continuous epidural infusion and patient-controlled epidural analgesia) provided significantly superior postoperative analgesia compared with intravenous patient-controlled analgesia, with the exception of hydrophilic opioid-only epidural regimens. Continuous epidural infusion provided statistically significantly superior analgesia versus patient-controlled epidural analgesia for overall pain, pain at rest, and pain with activity; however, patients receiving continuous epidural infusion had a significantly higher incidence of nausea-vomiting and motor block but lower incidence of pruritus. In summary, almost without exception, epidural analgesia, regardless of analgesic agent, epidural regimen, and type and time of pain assessment, provided superior postoperative analgesia compared to intravenous patient-controlled analgesia.     

Continuous epidural infusion of bupivacaine in labour

Thirty patients were given a constant epidural infusion in labour by gravity feed drip of approximately 10 ml of 0.25% bupivacaine per hr. The infusion proved a simple and reliable method of ensuring adequate analgesia throughout labour. There were no problems of drug toxicity and the incidence of complications and side effects was comparable to a previous series using intermittent 0.5% bupivacaine.