Outcomes of Epidural Versus Combined Spinal and Epidural (CSE) Anesthetic Technique on the Success of Trial of Labor After Cesarean (TOLAC): A Pilot Study
Phase: PHASE4
Conditions: Labor Pain, Complications; Cesarean Section, Pregnancy
Sponsor: The University of Texas Health Science Center, Houston

 
 
 
 
 
 
 
 
 
 
Outcomes of Epidural versus Combined Spinal and Epidural (CSE) Anesthetic 
Technique on the Success of Trial of Labor after Cesarean (TOLAC): A pilot study 
 
NCT02105558 
 
Version Date: 03/24/2014 
 
 

 
Department of Anesthesiology 
Scholarly Research Project Submission Form 
Name(s): Opal Raj, MD (PI), Madhumani Rupasinghe, FRCA (co PI)  
Faculty Mentor: Madhumani Rupasinghe, FRCA 
Category of Research:  Prospective randomized clinical pilot study 
Expected length of time for Project: One year or until 60 patients have been enrolled 
Title of Research Project: Outcomes of Epidural versus Combined Spinal and Epidural 
(CSE) Anesthetic Technique on the Success of Trial of Labor after Cesarean (TOLAC): 
A pilot study 
Summary of Project: To compare the effects of epidural versus CSE anesthesia on the 
success of TOLAC. This will be a prospective clinical study randomizing 60 eligible 
women into either an epidural group or CSE group. The effects of the specific regional 
anesthetic on patient's individual labor efforts will then be closely monitored. Written 
informed consent shall be obtained to enroll the patients in either group. Pain scores 
and electronic medical record information will be used with non-identifiable coding to 
determine the resulting outcomes.  
Background:   
Though it has been said, "once a cesarean, always a cesarean," the current medical 
stance has changed and now encourages VBAC in a select population of patients. 
VBAC has several advantages over a repeat cesarean including decreased recovery 
period, decreased risk of infection, avoidance of major abdominal surgery, and lessened 
blood loss (1). Predictors for success of VBAC include previous spontaneous vaginal 
birth, singleton pregnancy, and previous low transverse scar for C-section delivery (1). 
TOLAC is a reasonable option for select pregnant women and is associated with a 74% 
likelihood of VBAC (3). Risk factors for failure of VBAC include labor dystocia, advanced 
maternal age, maternal obesity, fetal macrosomia, GA>40 weeks, short inter pregnancy 
interval, and preeclampsia (1).  
While success of VBAC is associated with fewer complications, failure of VBAC may be 
associated with increased complications (1). A major concern for VBAC is the possibility 
for uterine rupture, which may result in hysterectomy and intrapartum fetal 
hypoxia/death. According to the ACOG guidelines, effective regional analgesia should 
not be expected to mask the signs and symptoms of uterine rupture, particularly 
because the most common sign of rupture is fetal heart tracing abnormalities. Adequate 

pain relief achieved with either CSE or epidurals may even encourage more women to 
opt for VBAC. The decision to proceed with TOLAC should occur only after appropriate 
discussion of the risks and benefits has occurred between the patient and her 
obstetrician and as long as no other contraindications exist. The final decision should be 
left up to the patient. There is no reliable way to predict risk of uterine rupture, but it may 
be associated with classical and low vertical uterine scars, induction of labor, and 
increased number of prior cesarean deliveries and risk may be decreased by previous 
vaginal birth (3). Other aspects of VBAC versus repeat cesarean pertaining to the fetus 
to consider include respiratory function, mother-infant contact, and initiation of 
breastfeeding, which may be delayed in cesarean deliveries (3).   
There is very little research concerning the effects of CSEs and epidurals on women 
undergoing TOLAC.There have been multiple studies comparing CSE and epidurals on 
nulliparous and multiparous women, but none have been done specifically on patients 
undergoing TOLAC. There is only one study comparing CSEs and epidurals in the 
general population demonstrating similar rates of hypotension and hemodynamic 
responses in 80 patients undergoing total knee replacement (8). According to the ASA 
practice guidelines for obstetric anesthesia "nonrandomized comparative studies 
suggest that epidural analgesia may be used in a trial of labor for previous cesarean 
delivery patients without adversely affecting the incidence of vaginal delivery. 
Randomized comparison of epidural versus other anesthetic techniques were not 
found." They agree that neuraxial techniques improve the likelihood of vaginal delivery 
for patients attempting VBAC and suggest neuraxial catheter be placed in event of 
operative delivery (9). Because no study to date has compared CSEs and epidurals and 
their effects on the success of VBAC, we would like to further investigate this arena.  
Inclusion criteria: (all patients meeting ACOG guidelines for TOLAC) ASA ll 
Patients 18 years of age or more with at least one previous elective cesarean 
delivery, <40 weeks gestational age (GA), vertex singleton pregnancy with use of 
continuous fetal monitoring.  
 
Exclusion criteria: Patients undergoing TOLAC but refusing regional anesthetic 
or with contraindication for regional anesthesia, less than 18 years of age, BMI 
>40 or with associated comorbidities such as gestational diabetes, preeclampsia, 
abnormal placentation, etc. 
Specific outcomes to be looked at include:  
Primary outcome: 
 Success of vaginal birth after cesarean (VBAC)  
Secondary outcomes: 

 Success of analgesia/ maternal satisfaction (self- rated pain score of 1-10 
prior to, 30 minutes after the regional anesthetic is performed and 24 hrs 
post-delivery)  
 If requiring a repeat C-section or instrumental delivery the success of 
regional anesthesia for the procedure. (self- rated pain score of 1-10 and 
necessity to use additional IV pain medication or conversion to general/ 
spinal  anesthesia) 
 Immediate side effects: fetal bradycardia, nausea, vomiting, pruritus, 
hypotension requiring vasopressors 
 Late side effects i.e. post dural puncture headache 
Methods:  
When the patient on the obstetric service requests an epidural for labor analgesia, a 
consult is immediately placed to the Anesthesia service. Patients who request neuraxial 
anesthesia for labor analgesia will then be screened for the study. Written informed 
consent shall be obtained from the patient prior to enrollment in this prospective 
randomized clinical study. The regional anesthetics will be placed by the obstetrical 
anesthesia team at Lyndon B. Johnson Hospital, a well-established partner of the 
University of Texas Medical School at Houston and a facility capable of performing an 
emergent C-section if necessary. Patients shall be randomized via computer generated 
randomization sequence and assigned a separate study number different from their 
medical record number. The study code and MRN will be saved on a linking log on a 
password protected drive. Standard ASA monitors will be applied to all patients 
including NIBP, pulse oximetry and fetal heart monitors. Patients will be bolused with 1 
liter of LR prior to the procedure via intravenous catheters. In the epidural group, 
epidurals will be placed in a sterile fashion using a 17g Tuohy needle to locate the 
epidural space via loss-of-resistance to saline at the lumbar vertebral level. 3 ml of 1.5% 
lidocaine with 5ug/ml of epinephrine will then be used for test dose to exclude 
intrathecal or intravenous placement of the catheter. Epidural solution composed of 5ml 
of 0.2% ropivacaine and another 5 ml of 0.2% ropivacaine will then be administered. In 
the CSE arm, the epidural space will again be located with a 17g Tuohy needle and 
dural puncture performed with 25g Pencan needle via needle-through-needle technique. 
Spinal injection of 2ml 0.2% ropivacaine will then be performed and spinal needle 
removed. An epidural catheter will then be placed and test dose performed with 3 ml of 
1.5% lidocaine with 5ug/ml of epinephrine. Maintenance dose will be via an epidural 
pump using 0.2% ropivacaine at a rate of 12 ml/hr. Self-determined numeric pain scores 
will be obtained prior to and after placement of the regional anesthetic and after delivery 
by nursing staff. Analgesia will be considered successful if the numerical pain score 
value is 3 or less.  
 

Data collection will be performed via pain scores obtained prior to and following 
placement of the regional anesthetic and establishment of analgesia, along with data on 
maternal satisfaction. Electronic medical records will also be used to gather the 
resulting outcomes. 
Data to be collected: 
Demographics:  
 
age  
 
weight  
 
height  
 
ethnicity  
 
gestational age  
 
reason for previous cesarean/incision type if known  
 
previous SVD 
 
pregnancy number  
 
cervical dilation at/near time of block (performed by obstetrician)  
 
estimated fetal weight 
 
Pain scores:  
 
before RA  
 
15 minutes, 30 minutes, and 60 minutes after RA 
 
24 hours after delivery 
 
Supplementation of catheter boluses for pain relief and total doses given 
 
Side effects of RA:  
 
pruritus  
 
nausea  
 
vomiting 
 
hypotension 
 
post dural puncture headache 
 
Neonatal outcome:  
 
fetal heart rate immediate post regional 
 
APGARs at 1 min and 5 min 

 
birth weight 
Delivery:  
 
date and time at which cervix becomes fully dilated (performed by 
obstetrician)  
 
date and time at which the following occur:  
 
SVD 
 
c-section 
 
instrumentation  
Maternal Satisfaction 
 
pain relief 
 
childbirth experience 
 
Data Analysis Plan: 
Power Analysis 
Our null hypothesis is that there is no difference in success of VBAC between epidurals 
and CSEs for women undergoing TOLAC. Our alternative hypothesis is that CSE will 
result in more successful VBAC than will epidurals.The success rate of VBAC is around 
74%.  Based on the literature, we expect the success rate with CSE to increase by 20-
25%; therefore, given our sample size of 60, we will have 80% power to detect a 
difference between the two groups. 
Primary Outcome 
The primary outcome, success for VBAC, will be assessed using χ2 or the Fisher Exact 
test, in case of cell sizes <5, to determine if the difference in success rates between the 
two analgesia groups, CSE and epidural, is statistically significant.  Logistic regression 
analysis will be used to adjust for potential confounders and other factors associated 
success or failure of VBAC. 
 
Secondary Outcomes 
The secondary outcome, success of analgesia, as measured by pain score on a scale 
of 1 to 10, will be assessed using ANOVA.  Difference in mean pain score between the 
two groups will be determined in a model with the continuous/count variable pain score 
as the dependent variable and analgesia group as the independent variable.   

Categorical outcomes, including success of regional anesthesia for patients requiring C-
section or instrumental delivery, immediate side effects, and late side effects will be 
evaluated using χ2 or the Fisher Exact test. 
References:  
1. American College of Obstetricians and Gynecologists. Obstet Gynecol. 
2010;116:450-463.  Practice Bulletin Number 115. Vaginal Birth after Previous 
Cesarean Delivery.  
2. Cappiello E, O'Rourke N, Segall S, Tsen LC. A Randomized Trial of Dural Puncture 
Epidural Technique Compared with the Standard Epidural Technique for Labor 
Analgesia. Obstetric Anesthesiology 2008; 107(5):1646-51. 
3. NIH Consensus and State-of-the-Sciences Statements. Volume 27, Number 3, March 
8-10, 2010. Vaginal Birth after Cesarean: New Insights.  
4. Tsen LC, Thue B, Datta S, Segall S. Is Combined Spinal Analgesia Associated with 
More Rapid Cervical Dilation in Nulliparous Patients When Compared with Conventional 
Epidural Analgesia. Anesthesiology 1999;91:920-5.  
5. Norris M, Fogel S, Conway-Long C. Combined Spinal-Epidural versus Epidural Labor 
Analgesia. Anesthesiology 2001; 95: 913-20.  
6. Hawkins JL. The Anesthesiologist's Role During Attempted VBAC. Clinical Obstetrics 
and Gynecology Volume 55, Number 4, 1005-1013.  
7. Jones L, Othman M, Dowswell T, Alfirevic Z, Gates S, Newburn M, Jordan S, 
Lavender T, Neilson JP. Pain Management for Women in Labour: An Overview of 
Systematic Reviews. The Cochrane Library 2012, Issue 3.  
8. Ezri T, Zahalka I, Zabeeda D, Feldbrin Z, Eidelman A, Zimlichman R, Medalion B, 
Evron S. Similar incidence of hypotension with combined spinal-epidural or epidural 
alone for knee arthroplasty. Canadian Journal of Anesthesia 2006: 53 (2): 139-145.  
9. Practice Guidelines for Obstetric Anesthesia. An Updated Report by the American 
Society of Anesthesiologists Task Force on Obstetric Anesthesia. Anesthesiology 2007; 
106:843-63.