Does Epidural Labor Analgesia Increase the Rate of Cesarean Section?-ft

Science Insights, 22 December 2016
Volume 2016
Doi: 10.15354/si.16.ar390
 
Original Investigation
Does Epidural Labor Analgesia Increase the Rate of Cesarean Section? A Retrospective Study
 
Hui Li, MD*,1; Yunhe Zhu, MD, MSc*,1; Yusheng Liu, MD, MSc*,1; Wangen Wang, MD*; Nan Wang, MD, MSc*; Shiqin Xu, MD, MPH*; Xiaofeng Shen, MD, MPH*,∆
 
Author Affiliations
*: Department of Anesthesiology, Affiliated Obstetric and Gynecological Hospital, Nanjing Medical University, Nanjing, China
1: These authors contributed equally to this work.
∆: Correspondence to: Dr. Xiaofeng Shen, MD, MPH, Department of Anesthesiology, Affiliated Obstetric and Gynecological Hospital, Nanjing Medical University, Nanjing, China. Email: sxf0418@126.com
 
 


ABSTRACT

OBJECTIVE
The aim of this study was to investigate the impact of epidural analgesia on the rate of Cesarean section in nulliparous women.
METHODS
Retrospectively a total of 200 nulliparous women who underwent spontaneous vaginal delivery at term with or without requesting labor analgesia were reviewed and screened. The primary outcome is the rate of Cesarean section at different cervix diameter. Others included maternal and neonatal outcomes due to epidural analgesia and drug delivery.
RESULTS
The data from a total of 139 subjects were eventually included into the analysis. Significant difference in the rate of Cesarean delivery was observed amongst the two groups (7.3% in patients with epidural analgesia versus 63.4% in patients without epidural analgesia, P < 0.0001). The pain rating, oxytocin use, and patient’s satisfaction were also superior in those underwent epidural analgesia than those without analgesia. No significant differences were expressed in variables of non-reassuring fetal status.
CONCLUSIONS
Epidural analgesia does not increase the rate of Cesarean section, on the contrary, it is a reliable way to reduce the rate compared with the patients who do not received the analgesia in nulliparous women.■

Keywords:  Epidural Analgesia; Labor Pain; Cesarean Section; Cervix; Nullipara

Sci Insigt. 2016; 2016:e00317 doi:10.15354/si.16.ar509

Current evidence supports that epidural analgesia is safe in laboring women and systematic reviews on this topic suggest bettering defining dystocia and non-reassuring fetal status diagnoses by precise and repeatable criteria (1-3). Nevertheless, ample evidence from both randomized controlled trials and well-designed observational studies suggest pregnant women with induced labor are at higher risk for Cesarean delivery, of which predominantly related to an unfavorable Bishop Score at admission (4-6). Under such circumstances, an interdisciplinary team approach and quality assessment is required for successful delivery care. A national wide survey in the United States unraveled that large differences exist in obstetricians’ approach to medical decision making with similar patient, and disclosed a real risk for nonevidence-based practice (7). Therefore, written evidence-based protocols are crucial for improving obstetric care outcome. The present study was designed to clarify the impact of epidural analgesia on the rate of Cesarean delivery in nulliparous women.
    



MATERIALS AND METHODS


After approval by the Hospital Ethics Examining Commit-tee of Human Research, the data of 200 nulliparous wom-en who underwent vaginal delivery at term with or without requesting labor analgesia were reviewed and screened. A total of 139 subjects met the criteria were assigned to this retrospective study. All those measure-up-to-standard par-ticipants who requested analgesia had signed an informed consent before initiation of analgesia.
          Participating data were excluded from the analysis if any of the following criteria were met: (i) Allergy to opi-oids, a history of the use of centrally-acting drugs of any sort, chronic pain and psychiatric diseases records; (ii) Participants younger than 18 years or older than 45 years; (iii) Those who were not willing to or could not finish the whole study at any time; (iv) Parturients with spinal ab-normalities, bleeding tendency, infection and anxiety to epidural puncture were not enrolled; (v) Alcohol addictive or narcotinum dependent patients were excluded for their influence on the analgesic efficacy of the epidural analge-sics; (vi) Subjects with a nonvertex presentation; (vii) Di-agnosed diabetes mellitus and pregnancy-induced hyper-tension; (viii) Twin gestation.
          Once the data of subjects were eligible for inclusion, all demographic and clinical data were added including age at delivery, weight, height, gestational age of fetus, current status of smoking, VAS rating of pain intensity and vital signs before analgesia, and whether spontaneous rupture of the membrane > 12 hrs before oxytocin infusion.
          The technique of epidural puncture and catheteriza-tion was performed to all participants. The test dose of 3.0 ml lidocaine 1.5% (45 mg) plus epinephrine 5 μg/ml was given to patients. After delivering test dose, all partici-pants immediately received an epidural bolus of analgesic mixture 15ml of ropivacaine 0.125% (1.25 mg/ml) with sufentanil, 0.3 μg/ml, followed by patient-controlled anal-gesic (PCA) pump with a 5 ml patient-controlled bolus without background infusion, a lockout interval of 15 min and hourly limit 30ml.
          The maternal parameters monitored during the whole study from before the analgesic procedures to the comple-tion of the labor including the heart rate by 5-lead electro-cardiograph, respiratory rate, noninvasive systolic and di-astolic blood pressure, mean arterial pressure and fingertip pulse oximetry. A catheter was inserted in a right or left antecubital vein for fluid and drug administration. Ring-er’s solution 8 ml/kg was titrated 15 minutes prior to initi-ation of EA. Intrapartum fluid management included re-placement of preexisting fluid deficits, normal losses (maintenance requirements), the amount of urine collected via a measurable basin-like container, and hemodynamic variables.
The intrauterine pressure sensor, if necessary, was placed to show the intensity of uterine contraction. Oxyto-cin was infused by the nursing staff set by the obstetricians according to clinical guidelines. A decision whether an operative delivery need to be proceeded to was made by the obstetrical team who did not involved in this study de-pending upon maternal and fetal indications.
          During the whole process of study, the patient-derived VAS scores of pain at rest were measured hourly with the 100-mm gauge (based on a 0-100 linear VAS, 0 = no pain; 100 = worst pain imaginable). Global pain to each patient, namely the pain intensity on average the patient felt during labor, was scored. In addition, the maternal sat-isfaction with analgesia was assessed via the VAS system (a 1-100 mm linear VAS used, 1 = dissatisfaction; 100 = fully satisfied).
          A continuous external electronic fetal heart-rate mon-itoring and tocodynamometry were made. Apgar scores were rated by the paediatric personnel according  
to the standard assessment. Umbilical-cord blood gas analysis was performed by the investigators.
          The rate of Cesarean delivery was selected as the primary outcome. The following measures were selected as the secondary outcomes: the verbal ratings of VAS pain and satisfaction with analgesia; oxytocin requirements; infant outcomes, such as the body weight, Apgar scorings.


Statistical Analyses


Analyses were performed using GraphPad Prism version 5.0 (GraphPad Software Inc., San Diego, CA, USA). Val-ues are expressed as the mean, standard deviation (SD), median, interquartile interval, or numbers. All categorical data were analyzed with a Chi-square test to indicate the trend. Continuous variables like as the effects of the epi-dural analgesia on patient’s self-rated VAS of pain and satisfaction were summarized by calculating the median and interquartile interval, and compared with the Kruskal-Wallis test. The demographic data and background charac-teristics were presented as mean ± SD and analyzed with Student t test. All reported P values are two-sided and a P value of less than 0.05 was considered to indicate statisti-cal significance.
    


RESULTS


Data from 200 patients were reviewed and screened for eligibility. A total of 139 subjects were collected and had the characteristics of epidural analgesia or without analge-sia. Sixty one (30.5%) were excluded.
          The material from included subjects underwent as-signment was analyzed for baseline characteristics. There were no significant differences in the demographic and background data between the two groups (Table 1). Vital signs all were within the physiological ranges throughout the analgesic period and not significantly different among the groups.
          A big difference in the rate of Cesarean delivery was shown in the two groups; the total difference in the CS rate in the patients with epidural analgesia was 7.3% and 63.4% in those without analgesia (P < 0.0001, Table 2). Along the changes in cervix diameter, the rate of CS showed sig-nificant change in analgesia group, in which the CS rate was marked reduced, whereas in the no-analgesia group, the rate increased and peaked as the cervix diameter reached 4 cm (Figure 1). In addition, the percentages of subjects who obtained oxytocin infusion also expressed significant difference (P < 0.01, Table 2).
          The pain scorings in both groups displayed substan-tial difference (VAS 25 versus 98 during the first stage in the analgesia and no-analgesia groups, respectively, P < 0.01; VAS 20 versus 85 during the second stage in the an-algesia and no-analgesia groups, respectively, P < 0.01, Table 2). Patients scored higher satisfaction of the analge-sia-related delivery experience than the comparison (P < 0.01, Table 2). There were no significant differences in Apgar scorings.


    


DISCUSSION


Our study demonstrated that epidural labor analgesia does not result in intrapartum Cesarean delivery in comparison with those without analgesia. On the contrary, epidural analgesia can reduce the rate of Cesarean section in nullip-arous women.
          While Dr. Wong found that intrathecal opioid use significantly shortened the first stage of labor compared with the systemic opioid administration (8), in the present study, epidural analgesia was not increase, but decrease Cesarean rate. It suggests that epidural analgesia in nullip-arous women is not a risk factor for Cesarean delivery. Nonetheless, one major finding in this study is that more oxytocin was prescribed to them for poor labor pain con-trolled patients who did not received epidural analgesia. These are not in agreement with other reports that an asso-ciation existed between EA and
intrapartum oxytocin infusion (9), and the EA combined with oxytocin infusion would increase the rate of CS (10). By contrast, out retrospective study did not show positive correlation between epidural labor analgesia and oxytocin, but a negative relationship.
          The study merely investigated the nulliparous women with single and vertex presentation, but whether such re-sults could be applied to other populations were not guar-anteed. Another question is the difficulty in blinding the study groupings from the obstetricians who ultimately made the decision for Cesarean delivery due to its retro-spective property. We monitored the fetal heart-rate as a possible indicator for emergency CS, though; the associa-tion amongst EA, fetal heart-rate variability and Cesarean delivery was not analyzed.
          In sum, when the EA was used in controlling labor pain, cervical dilation is not a major aspect needed to be concerned. Cesarean delivery in nulliparous women at term with vertex presentation was not increased when giv-ing epidural analgesia. Further perspective research is re-quired to determine whether other patient groups are also likely to fit in such treatment. ■
 


Acknowledgement
We are indebted to all obstetricians, midwives, pediatricians, nurses and anesthesiologists who participated in collecting the data in our hospital.
 


ARTICLE INFORMATION


Author Affiliations: Department of Anesthesiology, Affiliated Obstetric and Gynecological Hospital, Nanjing Medical University, Nanjing, China (Li, Zhu, Liu, Wang, Wang, Xu, Shen).
Author Contributions: Dr. Shen had full access to all of the data in the study and takes re-sponsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Li and Shen.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Li, Zhu, Liu.
Critical revision of the manuscript for im-portant intellectual content: All authors.
Statistical analysis: Li, Zhu, Liu.
Obtained funding: N/A.
Administrative, technical, or material support: Shen.
Study supervision: Shen.
Conflict of Interest Disclosures: All authors declared no competing interests of this manu-script submitted for publication.
Funding/Support: N/A
Role of the Funder/Sponsor: N/A
How to Cite This Paper: Li H, Zhu Y, Liu Y, Wang W, Wang N, Xu S, Shen X. Does epidural labor analgesia increase the rate of Cesarean section? A retrospective study. Sci Insigt. 2016; 2016:e00317.
Digital Object Identifier (DOI): http://dx.doi.org/10.15354/si.16.ar509.
Article Submission Information: Received, November 22, 2016; Revised: December 05, 2016; Accepted: December 11, 2016.

 



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