Progress of labor and obstetric outcome in parturients with combined spinal-epidural analgesia for labor: A comparative study.

Background: Alleviation of labour pain is known to improve maternal and fetal outcome. Combined Spinal-Epidural (CSE) analgesia is an excellent method. Aim and objectives: In view of reports of its concerns on labour, this study was conducted to evaluate the progress of labour, obstetric outcome in cases with and without CSE analgesia, the maternal pain relief and fetomaternal adverse effects. Materials and methods: In this comparative study, 60 parturients were allocated into case and control groups of 30 each. CSE analgesia was administered utilizing 0.5 ml of 0.125% Levobupivacaine / 0.2% Ropivacaine with 2 mcg/ml fentanyl. Progress of labour was recorded in partogram including duration of labour, mode of delivery, pain relief - Visual Analogue Scale (VAS) score, development of motor block, maternal satisfaction and Apgar score. Data was analyzed by Descriptive and Inferential statistics.
Results: Mean duration of first and second stage of labour among cases was 530±44.1 minutes, 61.5±12.7 minutes respectively and that of control was 526.6±64.9 minutes, 60±10.8 minutes respectively with no prolongation of labour P > 0.05. CSE analgesia did not alter the mode of delivery P=0.145 with rapid onset of pain relief. Apgar score was normal in both groups. Total 29 (97%) parturients experienced effective labour analgesia following CSE analgesia with VAS score 0. Maternal adverse effects included pruritus, transient initial motor blockade and post spinal headache.
Conclusion: CSE analgesia did not affect the duration of labour, mode of delivery with minimal fetomaternal adverse effects and provides rapid onset of pain relief . CSE analgesia can be considered for safe and effective labour analgesia.

INTRODUCTION

“The distress and pain which women often endure while they are going through labour are beyond description and seem to be more than human nature would be able to bear under any circumstances” stated Sir James Young Simpson, the father of obstetric anesthesia. The experience of labor pain is a complex and subjective interaction of multiple physiological, psychological, and sociocultural factors, in addition to each woman's individual interpretation of labor stimuli.[1] The excruciating labor pain and stress lead to an increase in maternal catecholamines, and along with maternal hyperventilation, can result in fetal asphyxia. Alleviating pain by providing proper analgesia can thus prevent fetal asphyxia.[2]

To provide ideal labor analgesia, the anesthesiologist must ensure that there is no adverse effect on maternal health, the newborn should not be depressed at delivery, the technique is simple and effectively relieves labor pain, and the efficacy of uterine contractions is not affected. It is also important to verify that the patient can cooperate intelligently with the medical and nursing staff, and there is minimal need for operative interference because of the analgesia. Among the available methods, regional analgesia appears to be the best, and when properly conducted, has minimal adverse effects.[2]

The American College of Obstetrics and Gynecology 2006 Committee states that “There is no other circumstance where it is considered acceptable for an individual to experience untreated severe pain, amenable to safe intervention, while under physician's care. In the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labour.”[3] Combined spinal–epidural (CSE) analgesia has become a popular technique as it combines the benefits of spinal analgesia due to its rapid onset of action, with the benefits of epidural analgesia and the availability of catheter for continuous infusion.[4]

This study was conducted to determine the merits and demerits of CSE analgesia. Its effect on the progression of labor and obstetric outcome was evaluated, with the aim to expand the knowledge base about labor analgesia. The primary objective was to study the progress of labor and obstetric outcome in parturients with and without CSE analgesia. The secondary objectives were to assess the maternal subjective pain relief with CSE analgesia and to evaluate the adverse effects if any.

SUBJECTS AND METHODS

This was a comparative study conducted on parturients admitted to the labor ward of the department of obstetrics and gynecology in a tertiary care teaching hospital attached to JSS Medical College, Mysore, in the southern state of India over a period of 18 months (between January 2018 and June 2019). After obtaining clearance from the Institutional Ethical Committee, sixty parturients were enrolled for the study and informed consent was obtained. The sample size was calculated using Cochran's formula with power of study of 80% and alpha error of 5%. Parturients were divided into 30 in each group.

The selected parturients were allocated into control group and study group of 30 women each by the draw of lots method. All primigravidae with a singleton pregnancy, term gestation, and vertex presentation with cervical dilation of 4 cm or more were included in the study. Those parturients with fetal malpresentation, obstetric complications, and comorbid conditions (bronchial asthma, cardiac disorders, and diabetes mellitus) and those with contraindications to regional analgesia were excluded from the study. Adequate history was taken with details of age, socioeconomic status, obstetric, gynecological, medical, and surgical history. Detailed clinical examinations including general, systemic, and obstetrical examinations were conducted.

Preanesthetic evaluation was done for those willing to undergo CSE analgesia. Before administering analgesia, baseline hemodynamic parameters, pain score, and fetal heart rate were recorded. CSE analgesia was administered using 0.5 ml of 0.125% levobupivacaine with 2 mcg/ml fentanyl. During the progression of labor, epidural top-up was administered if the Visual Analog Scale (VAS) score was >4. The mean onset of analgesia was defined as the time interval from the time of administration of CSE to achieving VAS ≤3 following the administration of analgesia. Parturients were observed throughout their labor period by monitoring the pulse rate, blood pressure, respiratory rate, oxygen saturation, fetal heart rate, and pain relief (VAS score). The pain was assessed by labor suite resident using a VAS score and was graded as mild (0–3), moderate (3–6), and severe (>6). The development of motor blockade was evaluated by a modified Bromage scale. Progress of labor was documented in partogram. Thirty minutes after each top-up, the parturients motor power was assessed using a modified Bromage scoring with the values as follows: modified Bromage score: 1 = complete block, 2 = almost complete block, 3 = partial block, 4 = detectable weakness of hip flexion, and 5 = no detectable weakness.

The mode of delivery whether by full-term normal vaginal delivery, instrumental vaginal delivery, or cesarean section was noted. Perinatal outcomes in the form of APGAR scores at 1st and 5th min were recorded, and parturients were monitored for 2 h in the postnatal period. The following day, an interview was taken from all participants to ascertain their views about the procedure, satisfaction with the pain relief, and if they experienced any adverse effects. Maternal satisfaction in this study was graded based on the subjective response from the parturients as satisfied and not satisfied.

Statistical analysis

Statistical Package for the Social Sciences (version 21.0) (IBM SPSS Statistics V21.0 NEW YORK, USA) was used for analyzing the data. Descriptive statistics such as mean, standard deviation (SD), frequency, and percentages and inferential statistics such as Chi-square test and independent t-test were used. Data were presented as mean ± SD, and P = 0.05 was considered statistically significant.

RESULTS

There were no statistically significant differences between the two groups with respect to maternal demographic characteristics with respect to age, height, weight, and body mass index (BMI) of the patient [Table 1]. The data were expressed as mean ± SD with P = 0.05 considered as significant. Among the parturients receiving labor analgesia through CSE, 26 parturients (86.7%) received analgesia at cervical dilatation of 4 cm and the rest at 5 cm.

Table 1

Demographic characteristics

	Mean±SD		P
	Study group (n=30)	Control group (n=30)
Age	26.1667±4.22703	24.6000±3.21205	0.111
Height (cm)	161.0000±2.4494	161.0600±2.6121	0.919
Weight (kg)	74.3000±3.2710	72.6667±4.03718	0.09
BMI (kg/m2)	28.6550±0.971	28.0250±1.5281	0.0617

SD=Standard deviation, BMI=Body mass index

The mean duration of the first stage of labor was 530 min in the study group and 526.66 min in the control group (P = 0.817). This shows there was no prolongation of first stage of labor in the study group as compared to the control group [Table 2 and Figure 1]. The mean duration of the second stage of labor in both the groups was comparable which indicates that there was no prolongation of the second stage of labor in the study group due to labor analgesia [Table 2 and Figure 2].

Table 2

Mean duration of first and second stage of labor

Type of parturients	Factors	n	Mean±SD	P
First stage (min)	Study	30	530.00±44.10	0.817
	Control	30	526.66±64.93
Second stage (min)	Study	24	61.50±12.762	0.778
	Control	29	60.50±10.565

SD=Standard deviation

Figure 1

Depicting mean duration of first stage of labor in minutes

Figure 2

Depicting the mean duration of second stage of labor in minutes

There was no statistically significant difference between the groups regarding the mode of delivery. In the study group, there were 64% spontaneous vaginal deliveries, 16% instrumental vaginal deliveries, and 20% underwent cesarean section due to complications such as nonreassuring fetal heart rate, deep transverse arrest, and secondary arrest of cervical dilatation. Overall, 80% delivered vaginally in the study group [Table 3]. Among the control group, 83% had spontaneous vaginal deliveries, 13% had instrumental vaginal deliveries, and 4% underwent emergency cesarean section [Table 3]. The mode of delivery was not significantly altered by the administration of labor analgesia (P = 0.145). Neonatal outcome was assessed based on APGAR scores at 1st and 5th min. The APGAR scores were ≥7 at 1 min and ≥8 at 5 min in both the groups, indicating that there was no neonatal distress [Table 4].

Table 3

Mode of delivery

Mode of delivery	FTND, n (%)	Outlet forceps delivery, n (%)	Ventouse delivery, n (%)	Caesarean section, n (%)	Total, n (%)
Study (n=30)	19 (64)	4 (13)	1 (3)	6 (20)	30 (100)
Control (n=30)	25 (83)	2 (6)	2 (7)	1 (4)	30 (100)
Total (60)	44	6	3	7	60

χ2=5.3896, P=0.145. FTND=Full-term normal vaginal delivery

Table 4

Apgar score 1st and 5th min

Type of parturients	Apgar (1 min)			Apgar (5 min)
	7	8	Total (n)	8	9	Total (n)
Study (n=30)	14	16	30	5	25	30
Control (n=30)	14	16	30	3	27	30
Total (60)	28	32	60	8	52	60

The onset of analgesia in the study group was 2 min in 65%, 3 min in 30%, and 5 min in 5% of parturients, with the average onset of pain relief being 2.5 min. The rapid onset of pain relief was due to the administration of intrathecal analgesia. Among the parturients receiving CSE, 74% required further epidural top-up doses, while 20% delivered before the effect of intrathecal analgesia was subsided without receiving any epidural top-up doses. When analyzing the quality of pain relief, we found that 97% of parturients in the study group achieved a VAS score of 0 following CSE analgesia and 3% had a VAS score of 3 [Table 5], while the parturients in the control group had a VAS score of more than 6 throughout labor. Initial motor block corresponding to modified Bromage score of 4 was seen in 87% of parturients, while 13% had a score of 3. The motor block regressed within 30 min did not alter the duration of second stage of labor and the mode of delivery.

Table 5

Visual Analog Scale score

Type of parturients	VAS score
	<3 (mild)	3-6 (moderate)	>6 (severe)	Total
Study (n=30)	29	1	0	30
Control (n=30)	0	0	30	30

VAS=Visual Analog Scale

Some maternal adverse effects were noted in a few parturients in the study group receiving CSE analgesia. Pruritus, which could be attributed to fentanyl, was reported in 30% of parturients. Postspinal headache was seen in 3% of parturients, and one parturient (3%) had persistent fetal bradycardia which resulted in cesarean delivery. The APGAR score at 1st and 5th min was more than 7 and there was no neonatal morbidity.

DISCUSSION

The widespread fear and anxiety among expectant mothers regarding the excruciating pain of childbirth is one of the most common reasons for maternal apprehension and the increase in the rate of delivery by cesarean section. Many opt for surgery as an escape from labor pain, resulting in an increase of C-section as the preferred mode of delivery in the present day. However, a mother who is able to undergo a normal vaginal delivery has many advantages over the one undergoing cesarean section as they have an earlier recovery period and a shorter hospital stay. By promoting labor analgesia and educating expectant mothers of its key role in alleviating pain, parturients can safely elect for vaginal delivery as an acceptable choice. CSE analgesia is a well-established and safe method of providing labor analgesia known as the walking epidural, CSE has its many advantages.

In our study, the mean duration of the first stage of labor was 530 min in parturients who received CSE analgesia and 526.66 min in parturients who did not receive CSE analgesia with P = 0.817, which shows that there was no prolongation of the duration of first stage of labor between the two groups. The same was seen during the second stage, with the average duration of the study and control groups being 61.5 min and 60.6 min respectively with P = 0.778 [Table 2]. Our study is comparable to studies conducted by Gambling et al.,[5] Singh et al.,[6] and Grant et al.[7]

CSE analgesia does not affect the mode of delivery in both the groups, as concluded in our study where P value was found to be 0.145. We found a positive correlation between our study and studies by Gambling et al.,[5] Singh et al.,[6] Grant et al.,[7] and Kurakazu et al.[8] The most common indications for cesarean section in these studies were arrest of progress of labor and nonreassuring fetal heart rate, as noted in our study [Figures 3 and 4].

Figure 3

Mode of delivery in parturients received combined spinal-epidural analgesia

Figure 4

Mode of delivery in parturients who did not receive combined spinal–epidural analgesia

Administration of local anesthetic through the spinal route provides immediate onset of analgesia till the epidural analgesia sets in. In our study, the mean duration of onset of analgesia was 2.5 min. Similar results were noted by Simmons et al.[9] Joel et al.,[10] and Braga et al.[11] In a retrospective study of 6497 deliveries comparing epidural analgesia and CSE analgesia for labor conducted by Miro et al.,[12] it was inferred that the quality of analgesia was better in the CSE group, a conclusion which is also shared by Wang and Xu.[13]

In our study, 9 parturients (30%) developed pruritus following CSE analgesia which is attributed to the opioid which was used. Pruritus was mild, transient, and had responded well to antihistamines. Similar findings were found by Singh et al.,[6] Joel et al.,[10] Patel et al.,[14] and Grangier et al.[15]

The neonatal outcome was assessed by APGAR score at 1 and 5 min. The APGAR score was ≥7 at 1 min and was ≥8 at 5 min in both the groups and was comparable Table 3. Similar to our study, in a meta-analysis of randomized control trials involving 2859 participants conducted by Wang et al.,[16] they found no difference between the APGAR score of study and control groups at 1 min and at 5 min. There was no respiratory distress among babies after delivery.

CSE analgesia causes sympathetic block and causes unopposed action of oxytocin and noradrenaline on the uterus due to dramatic reduction of plasma endorphins and epinephrine leading to uterine hyperactivity. These factors can predispose to decreased uterine blood flow, leading to fetal bradycardia.[13] In our study, only one parturient (3%) developed fetal bradycardia following the administration of CSE analgesia, for which she underwent an emergency cesarean section. The baby had no respiratory distress and had APGAR scores greater than 7 at 1 and 5 min. Gambling et al.[5] recorded the same adverse effect, though they reported a slightly higher incidence of 8.5%. Niesen and Jacob[17] describe that CSE increases chances of dose-related maternal pruritus, maternal hypotension, and fetal bradycardia.

Parturients did not complain of any discomfort such as pain or bleeding from the site of epidural catheter insertion at the time of discharge from the hospital. The same had been reported by Aragao et al.,[18] in their review of literature. Among parturients who received labor analgesia, 93.3% of them graded maternal satisfaction rate as satisfactory at the time of discharge [Table 6].

Table 6

Maternal satisfaction rate

Type of parturients (n=60)	Satisfied, n (%)	Not satisfied, n (%)
Study (n=30)	28 (93.3)	2 (6.7)
Control (n=30)	4 (13.4)	26 (86.6)

This research has certain strengths like for example, it is a comparative study wherein both the groups were compared with respect to age, gestational age, parity, and BMI. CSE analgesia was administered by the same anesthesiologist which eliminates interobserver variability. The limitation of our study was the small sample size; it is possible that the results of this study cannot be extrapolated to the general population.

CONCLUSION

The study concludes that labor analgesia by CSE technique did not affect the duration of labor or mode of delivery. It had minimal maternal and fetal adverse effects. CSE analgesia will provide effective labor analgesia with its rapid onset of action and provide pleasant painless labor as described by parturients in this study. It can be recommended routinely for labor analgesia.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.