Comparison of TAP, Anterior QL, or ESP Block for Elective Cesarean Section
Phase: PHASE4
Conditions: Pain, Postoperative, Cesarean Section
Sponsor: Duke University

Research Summary Version Date: 8/27/2018 
Protocol ID: Pro00100742 
Research Summary 
 
1.  Protocol Title:  
Comparison of TAP, Anterior QL, or ESP Block for Elective Cesarean Section 
 
2.  Purpose of the Study:  
The purpose of this prospective single center, randomized study is to determine if ultrasound guided 
Quadratus Lumborum (QL) and Erector Spinae Plane (ESP) blocks decrease opioid consumption 
compared to Transversus Abdominis Plane (TAP) in subjects undergoing elective cesarean section. Total 
opioid consumption and pain scores will be monitored for 48 hours postoperatively.  
 
3.  Background & Significance:  
Cesarean section is an invasive surgery that can lead to significant postoperative pain. Well controlled 
postoperative pain in this specific patient population can help minimize the effect of surgery on a new 
mother’s ability to care for her newborn and ease the transition back home, as well as allay any concerns 
regarding transfer of opiates through breastfeeding.  
 
The typical anesthetic plan involves a spinal anesthetic or combined spinal epidural anesthetic as the 
primary anesthetic for the procedure followed by a combination of oral pain medications, including 
opioids, to control pain postoperatively. Side effects from opioid use, including nausea, vomiting, 
sedation, or respiratory depression, can hinder a new mother’s ability to fully participate in the care of her 
newborn. Additionally, some women are leery to take opioids if they are breastfeeding for fear of transfer 
to their newborn [1]. Despite widespread postoperative prescription of opioids, women report poor pain 
control after cesarean section [2-4]. As part of a larger public health concern, unused postoperative 
opioids can be detrimental and the possibility of persistent opioid use after surgery is feasible in this 
patient population [5].  
 
TAP blocks have been utilized for years to help control incisional pain after abdominal surgeries, including 
cesarean section [6, 7]. However, it is not without limitations and there is some question regarding efficacy 
[8]. TAP blocks often decrease somatic pain, but do not impact visceral pain which can contribute to 
uncontrolled postoperative pain after cesarean section. Additionally, it has been shown that TAP blocks 
do not improve analgesia when patients are already receiving intrathecal morphine[9]. 
 
With newer truncal blocks like anterior quadratus lumborum (QL) and erector spinae plane (ESP) blocks 
coming into practice, it will be helpful to identify which, if any, of the three blocks can benefit this unique 
patient population.  
 
Studies involving earlier variations of the quadratus lumborum block have shown to be successful after 
cesarean section [10, 11]. At Duke University Hospital, we most commonly perform the anterior variation 
of the QL block which has not specifically been studied in this patient population. However, case series 
have demonstrated success in other abdominal procedures [12].  
 

Research Summary Version Date: 8/27/2018 
Protocol ID: Pro00100742 
Erector spinae plane blocks were initially used to treat pain from rib fractures and thoracotomies, but 
have now been shown to be effective for open abdominal procedures [13-15]. However, there has only 
been one case report to date using an ESP block for cesarean section [16].  
 
This study aims to answer if QL or ESP can impact postoperative opioid use and pain scores after 
cesarean section compared to TAP block.  
 
4.  Design & Procedures:  
 
  
The typical anesthetic for cesarean section at Duke University Hospital includes a spinal or combined 
spinal epidural anesthetic with intrathecal dosing of 1.4-1.6 mL bupivacaine HCl 0.75%, 15 mcg fentanyl, 
and 150 mcg morphine. If the epidural component of a combined spinal epidural anesthetic is used, the 
subject will be withdrawn from the study. Patients also receive rectal acetaminophen 975 mg prior to 
incision, intravenous (IV) ondansetron 4 mg, metoclopramiden10 mg, famotidine 20 mg and 
dexamethasone 4 mg intraoperatively, and IV ketorolac 15 mg prior to skin closure. There will be no 
change to this typical practice.    
  
Patients who consent to be in this study will be randomized to receive one of three truncal nerve blocks 
using an online randomization program by the study PI (AK/LG): (1) ultrasound-guided bilateral classic 
TAP block; (2) ultrasound-guided bilateral anterior QL (also known as transmuscular or QL type 3) block; 
(3) ultrasound-guided bilateral ESP block at the level of T9. These nerve blocks will be performed after 
delivery and within one hour of skin closure with 25 mL of 0.2% ropivacaine with epinephrine 1:400,000 
per side. Nerve blocks will be performed by a dedicated and trained group of regional anesthesiologists. 
This non-blinded regional anesthesiologist will save an ultrasound image after local anesthetic 
administration while the needle is still in position on each side. The study team will review these images 
to ensure a high quality of block performance.  
 
Patients will have standard postoperative pain medication orders, including acetaminophen 975 mg PO 
Q6H for 4 days (scheduled, starting 6 hours after intraoperative rectal dose), ketorolac 15 mg IV Q6H for 
24 hours (scheduled, starting 6 hours after intraoperative dose), ibuprofen 600 mg PO Q6H for 3 days 
(scheduled, starting 24 hours after first dose of ketorolac) and oxycodone 5-10mg PO Q3-4H PRN for 4 
days. If patients are unable to tolerate oral medication or oxycodone is insufficient, rescue medications 
may be ordered: IV morphine 1-2 mg or IV hydromorphone 0.3-0.5 mg Q4H as needed. There is no 
change from the standard postoperative order sets used for patients after cesarean section.  
 
Subjects’ verbal pain scores at rest and with movement as well as opioid consumption will be recorded 
at 2, 6, 24, and 48 hours postoperatively. The validated Obstetric Quality of Recovery-11 (ObsQoR-11) 
score will also be assessed at 24 and 48 hours postoperatively [17]. Additionally, the amount of 
antiemetics and antipruritics used will also be recorded at the above time points. These scores will be 
entered into a Duke University Hospital REDCap database. Subjects will also be sent a survey assessing 
their satisfaction with pain control one week after discharge via email or telephone. This information will 
be collected via Duke University Hospital REDCap.   
 
5.  Selection of Subjects: 

Research Summary Version Date: 8/27/2018 
Protocol ID: Pro00100742 
 
Patients undergoing elective cesarean section will be identified the day prior to surgery. Patients will be 
contacted via telephone by a member of the study team the day prior to surgery to confirm eligibility and, 
if eligible and interested, the study will be explained. Inclusion and exclusion criteria will be assessed 
through self-reporting by the subjects and review of patient chart on EPIC. Patients will be given the 
opportunity to ask initial questions about the study over the phone. Patients interested in participating will 
have the protocol fully explained and written informed consent will be obtained on the day of surgery prior 
to the procedure. The patient's care team, including attending surgeons, attending anesthesiologists, 
anesthesia residents, and nurse anesthetists will be informed of the patient's inclusion via secure email 
with specifics for the case. 
 
Inclusion Criteria: 
1) American Society of Anesthesiologists (ASA) Physical Status 1-3 
2) Age greater than or equal to 18 years 
3) Scheduled cesarean section 
4) English speaking 
 
Exclusion Criteria: 
1) ASA Physical Status 4-5 
2) Diagnosis of chronic pain  
3) Chronic opioid use (opioid use in the past 3 months) 
4) Preoperative use of SSRIs (Celexa, Lexapro, Prozac, Paxil), SNRIs (Cymbalta, Effexor), 
gabapentin, or pregabalin (Lyrica) 
5) Inability to cooperate with or understand protocol 
6) Inability to communicate pain scores or need for analgesia 
7) Infection at the site of block placement 
8) Intolerance or allergy to local anesthetics 
9) Neurologic deficit or disorder 
10) Blood thinning disorder or taking anticoagulant medication 
11) BMI > 50 kg/m2 
12) Suspected or known addiction to or abuse of illicit drug(s), prescription medicine(s), or alcohol 
within the past 2 years 
13) Uncontrolled anxiety, schizophrenia, or other psychiatric disorder that, in the opinion of the 
investigator, may interfere with study assessments or compliance 
14) Current or historical evidence of any clinically significant disease or condition that, in the opinion 
of the investigator, may increase the risk of surgery or complicate the subject’s postoperative 
course 
 
6.  Subject Recruitment & Compensation: 
Only patients who are having elective cesarean sections are eligible for this study. We will not bias any 
demographic groups in identifying patients eligible for this study. A total of 75 patients will be consented 
from Duke University Hospital. An IRB approved phone script will be used to discuss the study with 
eligible patients. Patients will not receive any additional compensation for enrollment in this study. 

Research Summary Version Date: 8/27/2018 
Protocol ID: Pro00100742 
 
7.  Consent Process: 
Potential subjects will be contacted and screened the day prior to surgery via telephone. If the patient is 
interested in the study, the consent process will take place in a private preoperative room on the Labor 
and Delivery ward prior to surgery. The consent process will be conducted by a member of the research 
team. Throughout the consent process, measures will be taken to maintain privacy, such as conducting 
face-to-face conversations in private rooms. As much time as necessary will be spent with each potential 
subject to sufficiently explain and answer all questions, and address all concerns they may have in regard 
to the study and/or consent process.  Under HIPAA waiver, the study team will identify potential subjects 
from clinic schedules, OR schedules, and Maestro Care. 
 
8.  Subject’s Capacity to Give Legally Effective Consent: 
Patients who do not have the capacity to give legally effective consent will not be approached for 
participation in this study.  
 
9.  Study Interventions: 
See 4 above. 
 
10. Risk/Benefit Assessment: 
Patients will be consented regarding the standard risks associated with regional anesthesia. These 
standard risks include: minor pain or discomfort; bruising; infection at the needle insertion site; injury to 
arteries, veins, or nerves affecting the abdomen, back, or legs; residual numbness, weakness, or 
paralysis; headache; muscle soreness. If patients are allergic to the local anesthetic (ropivacaine) or have 
an adverse drug reaction, they could possibly have a reaction that is severe enough to cause cardiac 
arrest and/or respiratory arrest. If there is injection of local anesthetic into a blood vessel, patients could 
possibly have loss of consciousness, seizure, or cardiac arrest. 
 
There have been rare case reports of hip or knee weakness after quadratus lumborum block. Therefore, 
patients will be encouraged to have someone with them to help them of bed the first time after the nerve 
block is performed. 
 
Benefits include contributing to general knowledge to improve future patient care.  Benefits also include 
potential analgesic benefit, decreased pain scores, and improved patient satisfaction.  Conversely, this 
study may show no benefit of the block, thereby invalidating the technique. 
 
11. Costs to the Subject: 
Subjects will not incur any additional costs to participate in the study.  A MaestroCare build will be created 
to ensure that any subjects are not charged for researched related procedures, equipment, or 
medications. 
 
12. Data Analysis & Statistical Considerations: 
A randomized trial of 75 subjects (25 per group) will provide 80% power to detect a 35% decrease in 
opioid use between treatment groups in a t-test at an alpha level 0.017 utilizing Bonferroni’s correction, 

Research Summary Version Date: 8/27/2018 
Protocol ID: Pro00100742 
(parametric), Mann-Whitney U Test (nonparametric), or repeated measures ANOVA as appropriate. 
Sample size and power calculations were performed using PASS v15 (NCSS, LLC. Kaysville, Utah). 
 
Patient and surgical characteristics will be summarized by standard descriptive statistics and will be 
compared between groups using t-tests, ANOVA, or Wilcoxon sum ranked tests as appropriate. We will 
report odds ratios, 95% confidence intervals, and p-values to assess significance and clinical importance 
of the observed treatment effect.  Additional measures of treatment efficacy (pain scores, ease of 
mobility, overall pain experience) will be summarized overall and between groups to further characterize 
the treatment effect in this population.   
 
 
13. Data & Safety Monitoring:  
In accordance with federal regulations the PI will monitor for, review, and promptly report to the IRB, 
appropriate institutional officials, sponsor, coordinating center and the appropriate regulatory agency 
head all unanticipated problems involving risks to subjects or others that occur in the course of a subject’s 
participation in a research study (45 CFR 46.103(b)(5)(i) and 21 CFR 56.108(b)(1)), all AE reports will be 
reported per the DUHS IRB policies. PI will be monitoring all AEs and submitting reports to the IRB per 
DUHS IRB policy. 
 
14. Privacy, Data Storage & Confidentiality: 
Potential subjects and their families will be approached in private rooms. Any guests not involved in the 
consent process will be asked to leave the room during any such communications, unless the patient 
allows them to be present.  Efforts to maintain subject confidentiality will include following Federal Privacy 
Regulations which provide safeguards for privacy, security, and authorized access. Except when required 
by law, subjects will not be identified by name, social security number, address, telephone number, or 
any other direct personal identifier in study records disclosed outside of Duke University Health System 
(DUHS).  Subjects will not be revealed in any reports or publications resulting from this study.   For 
records disclosed outside of DUHS, subjects will be assigned a unique code number. The paper and 
electronic data will be stored as per the RDSP. 
 
15. References: 
1. 
Marcus, M.A. and G. Brodner, Are opioids contraindicated as postoperative pain relief for patients who 
are breast-feeding their newborn? Curr Opin Anaesthesiol, 2001. 14(3): p. 287-9. 
2. 
Marcus, H., et al., Quality of pain treatment after caesarean section: Results of a multicentre cohort 
study. Eur J Pain, 2015. 19(7): p. 929-39. 
3. 
Bateman, B.T., et al., Patterns of Opioid Prescription and Use After Cesarean Delivery. Obstet Gynecol, 
2017. 130(1): p. 29-35. 
4. 
Osmundson, S.S., et al., Postdischarge Opioid Use After Cesarean Delivery. Obstet Gynecol, 2017. 130(1): 
p. 36-41. 
5. 
Bateman, B.T., et al., Persistent opioid use following cesarean delivery: patterns and predictors among 
opioid-naive women. Am J Obstet Gynecol, 2016. 215(3): p. 353 e1-353 e18. 
6. 
Eslamian, L., et al., Transversus abdominis plane block reduces postoperative pain intensity and analgesic 
consumption in elective cesarean delivery under general anesthesia. J Anesth, 2012. 26(3): p. 334-8. 
7. 
Fusco, P., et al., Transversus abdominis plane block for analgesia after Cesarean delivery. A systematic 
review. Minerva Anestesiol, 2015. 81(2): p. 195-204. 

Research Summary Version Date: 8/27/2018 
Protocol ID: Pro00100742 
8. 
Factor, D. and K.J. Chin, Transversus abdominis plane block in lower segment cesarean section: a 
question of block failure or lack of efficacy? Reg Anesth Pain Med, 2010. 35(4): p. 404-5. 
9. 
Kanazi, G.E., et al., The analgesic efficacy of subarachnoid morphine in comparison with ultrasound-
guided transversus abdominis plane block after cesarean delivery: a randomized controlled trial. Anesth 
Analg, 2010. 111(2): p. 475-81. 
10. 
Blanco, R., et al., Quadratus Lumborum Block Versus Transversus Abdominis Plane Block for 
Postoperative Pain After Cesarean Delivery: A Randomized Controlled Trial. Reg Anesth Pain Med, 2016. 
41(6): p. 757-762. 
11. 
Kadam, V.R., Ultrasound guided quadratus lumborum block or posterior transversus abdominis plane 
block catheter infusion as a postoperative analgesic technique for abdominal surgery. J Anaesthesiol Clin 
Pharmacol, 2015. 31(1): p. 130-1. 
12. 
Kadam, V.R. and S. Howell, Ultrasound-guided continuous transmuscular quadratus lumborum block- L4 
or L2 level catheter insertion for analgesia in open abdominal surgery: Case series. Indian J Anaesth, 
2018. 62(7): p. 555-557. 
13. 
Chin, K.J., L. Malhas, and A. Perlas, The Erector Spinae Plane Block Provides Visceral Abdominal Analgesia 
in Bariatric Surgery: A Report of 3 Cases. Reg Anesth Pain Med, 2017. 42(3): p. 372-376. 
14. 
Luis-Navarro, J.C., et al., Erector spinae plane block in abdominal surgery: Case series. Indian J Anaesth, 
2018. 62(7): p. 549-554. 
15. 
Tulgar, S., O. Selvi, and M.S. Kapakli, Erector Spinae Plane Block for Different Laparoscopic Abdominal 
Surgeries: Case Series. Case Rep Anesthesiol, 2018. 2018: p. 3947281. 
16. 
Yamak Altinpulluk, E., D. Garcia Simon, and M. Fajardo-Perez, Erector spinae plane block for analgesia 
after lower segment caesarean section: Case report. Rev Esp Anestesiol Reanim, 2018. 65(5): p. 284-286. 
17.  
Ciechanowicz, S., et al., Development and evaluation of an obstetric quality-of-recovery score (ObsQoR-
11) after elective Caesarean delivery. British Journal of Anaesthesia, 2019, 122 (1): 69-78.