Satisfaction, control and pain relief: short- and long-term assessments in a randomised controlled trial of low-dose and traditional epidurals and a non-epidural comparison group

Introduction 

Epidural analgesia results in greater maternal satisfaction and more effective pain relief than do other forms of labour analgesia when evaluated shortly after delivery.1, 2 Compared with higher-dose epidural blockade, low-dose techniques that increase mobility have also been shown to increase maternal satisfaction.3, 4 Retaining control is commonly quoted as an important criterion in the satisfaction of childbirth. This is supported by the findings of a national UK survey conducted by the National Birthday Trust,5 where feeling in control in labour was found to be an important part of a positive recollection of childbirth. One might expect good pain relief to increase the amount of control experienced. Conversely immobility as a result of epidural analgesia may reduce the amount of control felt.

The Comparative Obstetric Mobile Epidural Trial (COMET)6 showed an increase in spontaneous vaginal delivery rate with two low-concentration (and hence low dose) epidural techniques, without compromising the quality of pain relief, compared with epidural analgesia using 0.25% bupivacaine. Further questioning, after the birth and 12 months later, ascertained information about various aspects of satisfaction with labour and childbirth, including degree of control. This paper reports these assessments as secondary outcomes according to the type of regional analgesia received by group allocation and also compares these indices in a group that did not receive epidural analgesia.

Methods 

COMET recruited nulliparous women requesting epidural analgesia in labour to a two-centre (Birmingham and Leicester, UK) randomised controlled trial.6 The trial was approved by local research ethics committees in both centres. At 34 weeks of gestation nulliparous women booked at each unit were sent a study information leaflet; information was given again when epidural analgesia was requested and written consent was obtained by the duty anaesthetist. Women were recruited between August 1997 and April 2000.

Trial exclusion criteria were previous epidural, or spinal, the administration of pethidine in the previous 4h and any contraindication to epidural analgesia. Women were recruited throughout the day and night and randomised by a computer generated randomisation package to receive either a high concentration ‘traditional’ epidural (high-dose), a combined spinal-epidural (CSE) or a low-concentration infusion (or low-dose, LDI) as summarised in the box. Further details of the anaesthetic techniques and labour pain relief assessments have been previously published.7

	Box. Regional techniques
	Control:	Test dose 3mL 2% lidocaine
		10mL 0.25% bupivacaine after 5 minutes
		Top-ups 10mL 0.25% bupivacaine hourly as needed.
	CSE:	spinal:	1mL 0.25% isobaric bupivacaine+25g fentanyl
		epidural	15mL 0.1% bupivacaine+fentanyl 2μg/mL via epidural on return of painful contractions
		Top-ups 10mL 0.1% bupivacaine+fentanyl 2μg/mL every 30minutes as needed.
	LDI:	15mL 0.1% bupivacaine+fentanyl 2μg/mL
		10mL per hour of 0.1% bupivacaine+fentanyl 2μg/mL by continuous infusion.

All women in the trial and those in the comparison group were interviewed post partum, usually one day after delivery, by a research midwife. These midwives explained the purpose of the study to the non-epidural group and obtained consent for the interview. At this interview questions were included to obtain a variety of indicators of women’s satisfaction with the birth experience and pain relief and its effects. Visual analogue scores (VAS) of efficacy of analgesia (0=no pain; 100=worst pain imaginable) and the degree of control were measured (0=full control; 100=no control whatsoever) as recalled the day after delivery. Full control was accepted only as a VAS of 0.

To assess longer term views a postal questionnaire was sent 12 months after the delivery to all women except those whose baby was known to have died. This questionnaire was also used to establish any complications or side effects related to childbirth, which are reported elsewhere.8, 9 The questions relevant to the findings reported here are in Appendix 1 (see web).

Results 

One thousand and fifty-four women were randomised to receive one of three epidural techniques and 351 women were recruited to the comparison group (Fig. 1). Between 86.9 and 89.3% women in each group were Caucasian. The mode of delivery and numbers recruited to each group illustrate the previously reported findings of an increase in spontaneous vaginal delivery with both mobile techniques and the expected higher number of spontaneous vaginal deliveries and fewer operative deliveries, especially by caesarean section, in the comparison group (Table 1).6 The most common types of pain relief used by women in the non-epidural group were Entonox (total usage 85%, sole usage 31%) and pethidine (total usage 43%, sole usage 3%). Transcutaneous electrical nerve stimulation was used by 16%, almost always in combination, and 7% used no pain relief.

View Large Image Download to PowerPoint

Fig. 1. Progress through trial and comparison group follow-up.

Table 1. Mode of delivery

		High-dose	CSE	LDI	No epidural⁎
		n=353	n=351	n=350	n = 351
	Spontaneous	124 (35)	150 (43)	150 (43)	259 (74)
	Vaginal instrumental	131 (37)	102 (29)	98 (28)	52 (15)
	Caesarean section	98 (28)	99 (28)	102 (29)	30 (9)

Data are number (%). CSE: combined spinal-epidural; LDI: low-concentration/dose infusion.

⁎ Mode of delivery of 10 women in this group was not recorded.

Satisfaction with pain relief 

The main pre-specified overall VAS assessment of pain during labour after administration of pain relief were 14 (high dose), 10 (CSE) and 12 (LDI) [median scores, VAS 0-100] which illustrates the effectiveness of epidural analgesia. This contrasted to a median VAS of 62 for the non-epidural comparison group. Sixty-one to 63% of women who received epidural analgesia had a VAS of less than 20 compared with only 7% of those who did not receive epidural analgesia.

The overall degree of satisfaction with the epidural was similar for all three techniques (Table 2). Satisfaction with speed of onset of pain relief was significantly greater for the CSE than for the high-dose technique, whilst LDI and high dose were similar in this respect. As would be expected, the mobility experienced by women was significantly greater for both CSE and LDI relative to high-dose techniques, and the women’s satisfaction with the amount of movement was correspondingly greater. Comparing the two low-dose techniques, satisfaction with the speed of pain relief, the amount of movement and satisfaction with this were all significantly greater for the CSE than for the LDI technique (P <0.001 for all three comparisons).

Table 2. Visual analogue scores for satisfaction with aspects of epidural

		High-dose	CSE	P value	LDI	P value	No epidural	P value
		n=349	n=348		n=344		n=351
	Overall satisfaction with epidural†	4	2	0.210	4	0.939	N/A
	Satisfaction with speed of pain relief†	6	0	<0.001	6	0.746	N/A
	Amount of movement††	64	18	<0.001	29	<0.001	N/A
	Satisfaction with amount of movement†	17	1	<0.001	5	<0.001	N/A
	Amount of control felt during labour†††	34	25	0.018	27	0.138	26	0.255

Data are median values.

† (0 = Completely satisfied, 100 = Completely dissatisfied) †† (0 = Complete movement, 100 = Could not move at all) ††† (0 = Complete control, 100 = No control at all). CSE: combined spinal-epidural; LDI: low-concentration/dose infusion.

Mobility and birth position 

Women’s responses on whether they had walked in labour as much as they had expected, or had delivered the baby in the position they had hoped for did not differ between the trial groups (Table 3). The views of the non-epidural comparison group, however, did differ from the high-dose epidural group, being more likely to walk as much as expected and to have been undecided about their hoped-for delivery position.

Table 3. Mobilisation in labour and delivery position

		High-dose	CSE	P value	LDI	P value	No epidural	P value
		n=349	n=348		n=344		n=351
	Walked in labour as much as expected	107 (31)	123 (35)	0.237	126 (36)	0.133	137 (39)	0.030
	Delivery of baby in position hoped for
	yes	70 (20)	75 (22)	0.396	55 (16)	0.061	80 (23)
	no	143 (41)	126 (36)		127 (37)		104 (30)	0.005
	undecided	133 (38)	146 (42)		162 (47)		167 (48)
	missing	3	1

Data are number (%). CSE: combined spinal-epidural; LDI: low-concentration/dose infusion.

Degree of control 

The overall degree of control the women said they had felt during labour was greater for both low-dose techniques relative to the high-dose group, although the difference was statistically significant at the 95% level for the CSE technique only (Table 2). The degree of control felt by women in the non-epidural group was not significantly different from the high-dose epidural technique and the median value was similar to the mobile techniques. Since there were substantially more spontaneous vaginal deliveries in the non-epidural relative to the epidural groups, which is likely to be related to feelings of control over labour, this was examined further according to mode of delivery (Table 4). Among those who had a spontaneous delivery, more women in the CSE group (30%) felt in full control compared with the high-dose group (17%) (P<0.05). By comparison 22% in the LDI group and only 15% who had no epidural felt in full control. The perception of control, both median values and proportion with full control, was generally greater in those who had a spontaneous vaginal delivery compared with instrumental or caesarean delivery.

Table 4. Control felt over labour by study group and mode of delivery

		High-dose	CSE	LDI	No epidural
	Spontaneous (n)	122	147	147	249
	Median VAS	24	19⁎	15	21
	Instrumental (n)	129	102	96	51
	Median VAS	42	29	29	31
	Caesarean (n)	95	99	101	29
	Median VAS	44	40	43	51

VAS =visual analogue score (0 = full control, 100 = no control).

⁎ P<0.05 compared to control. CSE: combined spinal-epidural; LDI: low-concentration/dose infusion.

Among those who had instrumental deliveries, feelings of control were similar for the mobile and non-epidural groups relative to the high-dose group. Among the caesarean deliveries there was also no difference according to type of epidural. Significantly less control was felt by the non-epidural women, not surprisingly since they received general anaesthesia.

Twelve-month assessments 

There was a 78% response rate to the questionnaire sent 12 months after delivery for each of the epidural groups and a 73% response from those in the non- epidural comparison group (Fig. 1). The characteristics of the responders and non-responders at twelve months were similar.

At 12 months post partum women’s rating of their overall childbirth experience did not differ between the epidural groups (Table 5). Median VAS for satisfaction was significantly higher in women in the non-epidural group. When separated according to mode of delivery, this difference was only shown among spontaneous vaginal deliveries; among operative births women’s evaluations were similar with or without epidural.

Table 5. Visual analogue scores for long-term overall childbirth experience.

		High-dose	CSE	P value	LDI	P value	No epidural	P value
		n=262	n=266		n=262		n=251l
	All delivery modes (n)
	Visual analogue score	46	47	0.665	49	0.123	63	<0.0001
	Missing (n)	11	17		8		15
	Spontaneous (n)	87	110		114		182
	Visual analogue score	52	53	0.470	61	0.109	68	0.001
	Missing (n)	2	10		5		11
	Instrumental (n)	109	77		77		37
	Visual analogue score	42	45	0.747	48	0.200	52	0.289
	Missing (n)	6	4		2		2
	Caesarean (n)	66	80		72		19
	Visual analogue score	40	38	0.538	30	0.382	26	0.276
	Missing (n)	3	4		2		0

Data are median visual analogue score (0=absolutely awful, 100=absolutely wonderful). CSE: combined spinal-epidurnal; LDI: low-concentration/dose infusion.

Choice of pain relief in the event of a subsequent birth was another long-term assessment. A significantly higher proportion of the women in both mobile groups said they would choose a mobile epidural again than was the case for the high-concentration epidural technique. The proportion who would want a mobile epidural again, either definitely or as a possibility, was 69% (183/266) for CSE and 69% (180/262) for LDI, compared with only 26% (68/262) (P<0.001) who would consider the high-concentration technique again. In the non-epidural group 89% (224/251) of women would not want an epidural for a subsequent delivery.

Discussion 

Sine the early 1990s changes in the delivery of maternity care in the UK have recognised the importance of women’s views and their satisfaction with the service.11 The most recent Department of Health publication Maternity Matters concentrates on delivering choice to enable pregnancy and birth to be as safe and satisfying as possible.12 Although labour, and in particular the type of pain relief, is only one small component of the total maternity service, it is nevertheless important, especially to anaesthetists trying to deliver optimum analgesic services. The complexities of assessing maternal satisfaction are comprehensively reviewed by Robinson et al., who point out the importance of knowing the questions asked of women.13 Our study sought the effectiveness of pain relief, the satisfaction with speed of onset of pain relief with the different types of epidural and the overall satisfaction with the epidural or other type of analgesic technique. Although women were aware if they had a mobile technique they were not told of any differences in speed of onset between the types and hence were not biased in this respect. The women appeared to understand the concept of visual analogue scores as the contemporaneous comments accorded with the scores, and the early effectiveness of the CSE technique was reflected in the contemporaneous pain scores. The high degree of efficacy in reducing pain scores, as well as satisfaction with epidural analgesia, were confirmed in this study but, in contrast with others,3, 4 we did not find an even higher overall degree of satisfaction with low-dose techniques. Nageotte et al., like ourselves, had asked women to rate overall epidural satisfaction and found no difference between CSE and a higher dose technique.14

The striking finding of our study was a much higher degree of satisfaction overall, both at the time of birth and looking back 12 months later when birth resulted in a spontaneous delivery. Although this is not surprising it is not something over which a woman has a great deal of influence, except perhaps pushing harder in the second stage. However, the woman does have a choice over whether she wants epidural analgesia and whether she knows enough to specifically request a low-dose technique that may increase her likelihood of spontaneous delivery. The association between spontaneous delivery and a higher degree of satisfaction and the fact that effective epidural analgesia does not necessarily enhance satisfaction when judged some time later, have been previously demonstrated.15 Our study does not show any enhanced benefit in overall childbirth experience through having a low-dose epidural rather than a high concentration technique, whether assessed at the time of delivery or 12 months later. However, the popularity of low-dose techniques, relative to higher dose epidural pain relief, expressed by women when speculating about their choices for future deliveries, was very evident.

A limitation of our study was the fact that we only looked at limited aspects of satisfaction. For instance we did not examine the effect on satisfaction of the increased likelihood of urinary catheterisation during labour and slower return of voiding sensation associated with the higher concentration when compared with CSE.8 To have covered all such aspects would have required a much longer questionnaire and a balance must be struck in questionnaire design between obtaining data on everything of interest and the likelihood of women answering.

Many women choose not to walk about during labour, even when they are encouraged to do so,16 and only about a third in each mobile group actually did walk in our trial.9 Although the expectation of mobility was similar between the epidural groups, and in fact, similar to the non-epidural group, the amount of movement women had and their satisfaction with this was greater for the low-dose regimens than for the high concentration. It would seem that even though many women did not walk, being able to move and having the ability to walk makes them more satisfied with this aspect of analgesia. This also has practical benefits for those caring for women, reducing dependence on others for simply moving about the bed.

Like satisfaction, the factors affecting perception of control are likely to be multifaceted. Being a large randomised controlled trial, we expected that factors that might affect satisfaction and control, such as time of labour (night or day) and personnel attending the parturient, which delivery room was used, would not affect one group more than another. Multivariate analysis was therefore not felt to be needed.

It is evident that being able to move allows the woman more control but despite this we found that the method of analgesia used in labour had no effect on the perception of control if delivery of the baby needed to be assisted by forceps. Perhaps this illustrates the focus of the woman on the moment of delivery and a feeling of handing over control to the person effecting delivery. Interestingly, non-epidural analgesia was not associated with any greater perception of control than traditional higher concentration epidural analgesia. This could be interpreted that experiencing pain reduces control, but the relief of pain with old fashioned epidural techniques induces a similar feeling of lack of control, because of the accompanying motor block. The perception of control was shown as a benefit of the low concentration techniques with significant percentages feeling totally in control.

How generalisable are our findings? We studied a cohort of nulliparous women who wanted epidural analgesia and were prepared to enter a study that involved random allocation to different ways of administering epidural analgesia. This makes the comparison between the epidural groups very robust but does not take into account women who have fixed views about the type of analgesia they want or those of women who have previously given birth. The population of our study and comparison groups did not reflect the patient population in the hospital at the time. Nearly 90% of those who gave consent for the study were Caucasian whereas Caucasians made up only 60% of the patients at the time. This accounted for the need to match for ethnic background in the comparison group. Whereas we can be very confident about comparisons between epidural groups we can be less so between the epidural groups and non-epidural group. Whilst the non-epidural group were also willing to answer questions, trying to match for mode of delivery without regional anaesthesia being used, meant inevitably that some women had general anaesthesia for delivery by caesarean section. The likely urgency of the situation and being unaware of the delivery itself is very likely to have affected the satisfaction and degree of control that these women experienced. Nevertheless one of the advantages of existing epidural analgesia is the ability to extend the block quickly should urgent delivery be necessary and therefore there is some validity for comparing satisfaction and control with the comparison group that we identified. Another point to be borne in mind is that the epidural groups had their pain assessed during labour whereas the comparison group were remembering their pain the following day.

Whilst data from this study reflect women’s views approximately 10 years ago we feel it is still relevant as the analgesic techniques continue to be used, albeit the development of patient-controlled epidural analgesia might be expected to give the mother a greater feeling of control. In conclusion satisfaction with the experience of childbirth appears intimately related to the attainment of a spontaneous delivery, and mobile epidurals enhance women’s feeling of control in labour and are popular for future choice of epidural analgesia.