Ultrasound-Guided Modified Pectoral Plane (PECS II) Block Versus Erector Spinae Plane Block (ESPB) for Postoperative Analgesia of Modified Radical Mastectomy
Phase: NA
Conditions: Anaesthesia
Sponsor: Ain Shams University

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 1 
 
 
PROTOCOL OF A THESIS FOR PARTIAL FULFILMENT OF 
MASTER’S DEGREE IN ANESTHESIOLOGY, INTENSIVE CARE AND PAIN 
MANAGEMENT 
 
Title of the Protocol 
Ultrasound-Guided Modified Pectoral Plane (PECS II) Block versus 
Erector Spinae Plane Block (ESPB) for Postoperative Analgesia of Modified 
Radical Mastectomy 
 
 
Post-graduate Student: Nada Nassuhy Maamoun Abdelrahman Zoair. 
Degree: M.B, B.Ch., Faculty of Medicine, Ain-Shams University. 
NCT: NCT06714682 
DATE OF DOCUMENT: 1/8/2024 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Faculty of Medicine 
Ain Shams University 
2024 
 
 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 2 
 
 
 
 
What is already known on this subject? What does this study add? 
      
      Modified Radical Mastectomy (MRM) is a surgical procedure that 
removes the entire breast, including the skin, breast tissue, areola, and nipple, 
along with most of the axillary lymph nodes. However, most of the chest 
muscles are left intact. It is a less invasive surgery than a radical mastectomy, 
which also removes the chest muscles. It is a standard option for treating 
breast cancer that has spread to the axillary lymph nodes.       
Postoperative pain in MRM is a common problem that can affect the 
quality of life and recovery of patients. Postoperative pain management is 
becoming an integral part of anesthesia care. Optimal pain control in patients 
undergoing MRM is imperative for good rehabilitation and functional 
outcomes. Current modalities in use aim to reduce postoperative opioid 
consumption to control postoperative pain thus minimizing its side effects in 
what is recently known as multimodal analgesia techniques. 
Regional blocks have been introduced for postoperative pain relief such 
as thoracic epidural block (TEB), thoracic paravertebral block (TPVB) and 
intercostal blocks. The use of ultrasound guidance has much improved the 
success rate of the nerve blocks and the development of new techniques.     
Newer pain control modalities have been used providing adequate pain 
relief, not affecting muscle strength and utilized as excellent solutions for 
multimodal analgesia peri-operatively. Examples of these modalities are 
serratus anterior plane (SAP) block, pectoral nerve (PECS) block and erector 
spinae plane block (ESPB). 
In this study we will compare the analgesic efficacies of modified pectoral 
plane (PECS II) block versus erector spinae plane block (ESPB) after MRM 
surgery.  
 
 
 
 
 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 3 
 
 
1. 
INTRODUCTION / REVIEW: 
Breast cancer (BC) is the most common type of female cancer in Egypt 
with an age-specific incidence rate of 48.8/100,000. Although incidence rate 
in Egypt is lower than the global figures, mortality is higher at an age-
standardized rate of 20.4/100,000 compared with the US rate of 
12.3/100,000 and the developed countries' rate of 12.8/100,000 (Sung et al., 
2021) (Globocan, 2020). 
It is the most commonly diagnosed cancer worldwide, with estimated 
new cases exceeding 2 million in 2020. Furthermore, it represents the 
leading cause of cancer death in women, with more than 680,000 deaths 
(Sung et al., 2021). 
During MRM, some of the nerves in the chest are affected so most 
women have some level of pain in the days after the procedure. Severe acute 
postoperative pain following breast surgery is an independent risk factor in 
the development of chronic post-mastectomy pain (Bakeer et al., 2020), not 
only increasing the risk of persistent agony and prolongs hospitalization, it 
also affects recovery and increases healthcare costs (Deng et al., 2020).  
Multimodal techniques for pain management have been recommended by 
the American Society of Anesthesiologists (ASA) for the management of 
acute postoperative pain (Apfelbaum et al., 2012) (Nagaraja et al., 2018). 
These techniques include oral analgesics as opioids, paracetamol and 
nonsteroidal anti-inflammatory drugs (NSAIDs) (Nagaraja et al., 2018), 
intravenous (IV) and regional analgesia. Inappropriate postoperative 
analgesia may increase morbidity and mortality (Blanco R, 2011).   
PECS-II block is an interfascial plane block in which local anesthetic is 
injected between serratus anterior and pectoralis muscles that blocks the 
pectoral nerve as well as the long thoracic, intercostobrachial and lateral 
cutaneous branches of the inter-costal III, IV, V, and VI nerves. PECS-II is a 
less invasive and easier to be performed alternative to thoracic paravertebral 
block (TPVB). This block, defined by Blanco et al., provides safe and 
adequate post-operative analgesia in the anterior chest wall after breast 
surgery. The most common complications are pneumothorax, vascular 
puncture, infection, local anesthetic systemic toxicity (LAST), allergy and 
failed block (Blanco et al., 2012) (Wang et al., 2018). 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 4 
 
 
ESPB is a paraspinal fascial plane block in which local anesthetic is 
injected between the tip of the transverse process of the spine and the 
anterior fascia of the erector spinae muscles blocking the dorsal and ventral 
rami of the spinal nerves, as well as the sympathetic chain, resulting in 
analgesia of chronic thoracic neuropathic pain, breast and upper abdominal 
surgeries. The block, defined by Forero et al., can cover several spinal nerve 
levels above and below the injection site as the local anesthetic spreads along 
the fascial plane, depending on the volume and concentration of the local 
anesthetic (Forero et al., 2016) (Bonvicini et al., 2017) (Chin et al., 2017). 
The main advantages of this technique include the ease of performing it, the   
analgesic efficacy and the low risk of complications as Pneumothorax, hemi-
diaphragmatic paralysis, motor weakness, and neurological findings related 
to local anesthesia toxicity (Tulgar et al., 2019). 
 
 
2. 
AIM / OBJECTIVES: 
This study aims to compare the analgesic efficacies of the modified 
pectoral plane block (PECS II) and the erector spinae plane block (ESPB) 
after modified radical mastectomy surgery. 
 
 
3. 
METHODOLOGY: Patients and Methods 
➢ 
Type of Study: Prospective randomized comparative clinical study.  
➢ 
Study Setting:  Ain Shams University Hospitals, Cairo, Egypt. 
➢ 
Study Period:   6 months to 12 months, starting from approval of 
the protocol, both from scientific and ethical committee. 
➢ 
Study Population:   
• 
Inclusion Criteria: 
1- Female patients scheduled for MRM. 
2- Age eligible ≥ 40 & ≤ 65 yrs. 
3- Patients with American Society of Anesthesiologists (ASA) physical 
status I, II who will be scheduled for MRM surgery. 
• 
Exclusion Criteria:  
1- Age < 40 & > 65 years old. 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 5 
 
2- Declining to give written informed consent. 
3- History of allergy to the medications used in the study. 
4- Contraindication to regional anesthesia [including coagulopathy 
(platelet count ≤ 80,000, INR ≥ 1.5) and local infection]. 
5- Severe hepatic impairment (INR ≥ 1.5, Bilirubin ≥ 2, Albumin ≤ 2). 
6- Renal dysfunction [GFR < 50 ml/min calculated by MDRD 
(Modification of diet in renal disease) equation for GFR estimation (Livio et 
al., 2008)]. 
7- Psychiatric disorder. 
8- Pregnancy. 
9- Patient with history of thoracic spine surgery. 
➢ 
Sampling method: Simple random sampling. 
➢ 
Sample Size: 
     Using PASS 15 program for sample size calculation, setting power at 
90% and alpha error at 0.05 and according to “Bakeer & Abdallah, 2022”, 
the expected median VAS score 1-hour post-operative in PECS II group = 
1(1-2) and in ESPB group= 2(1-3). Sample size of 10 patients per group will 
be needed to detect the difference between two groups. 
➢ 
Ethical consideration: 
Patient informed written consent and approval of the Research Ethical 
Committee of the Faculty of Medicine; Ain Shams University will be 
obtained before patient’s allocation. 
➢ 
Study procedures:  
• 
Preoperative settings:  
All patients will be assessed preoperatively by careful history taking, full 
physical examination, laboratory evaluation and other appropriate 
investigations. 
At the preoperative visit, all patients will be instructed on how to evaluate 
their own pain by using a 10-cm visual analogue pain scale (VAS) (0 = no 
pain, 10 = maximum pain imaginable). 
The nerve block will be performed in the preoperative block area 
following standardized monitoring, including non-invasive blood pressure 
(BP), electrocardiogram (ECG), and pulse oximetry (PO). Oxygen 2–3 
L/min will be applied through the nasal cannula and IV midazolam 0.025 
mg/kg will be given and dose may be repeated every 3-5 minutes until 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 6 
 
sedation is adequate and patient still arousable up to 20 mg (Pedro et al., 
2022). All blocks will be performed by the same two experienced senior 
attending doctors in ultrasonic-guided nerve blocks. Patients will be 
randomly divided according to a computer-generated random number table 
into two groups: 
➢ 
Group 1 (PECS II group): patients will receive ultrasound guided 
PECS II block (10 patients). 
➢ 
Group 2 (ESPB group): patients will receive ultrasound guided 
erector spinae plane block (10 patients). 
Both blocks will be performed under complete aseptic precautions using 
ultrasound machine with high-frequency linear probe covered with sterile 
sheath (Sonosite M-turbo c, Bothell, Washington, USA) and linear 
ultrasound probe (2.5-7.5MHz) and a 22G 100 mm echogenic needle (B- 
Braun Medical Inc., Bethlehem, PA, USA) which will be inserted after 
standard skin disinfection and infiltration of 2 millilitres (mL) lidocaine 2% 
subcutaneously. 
Pre-operative chest ultrasound will be done by the anesthesiologist to 
detect complications after puncturing of the blockade (hematoma in the 
puncture 
site 
by 
direct 
visualization 
and 
pneumothorax 
by 
Barcode/Stratosphere sign). 
➢ 
In the PECS II group: - 
The patient will lay supine with the ipsilateral arm abducted and 
externally rotated and the elbow flexed at 90 degrees. The high-frequency 
linear probe will be placed transversely between the clavicle medially and 
above and the shoulder joint laterally. After identifying the pectoralis major 
and minor muscles and the plane between them, the probe will be angled 
caudally to look for the pulsating pectoral branch of the thoraco-acromial 
artery; if it couldn’t be found, the probe will be pushed 1-2 cm caudally and 
medially. In a caudal tilt, within a biconvex space, the artery will be 
recognised. After that, the block needle will be inserted in an in-plane 
approach to the artery’s location and 10 mL of 0.25% bupivacaine will be 
administered (Pani et al., 2019). Then probe will be moved laterally and 
caudally towards the anterior axillary fold until the serratus muscle appears 
beneath the pectoralis minor muscle attaching to the underlying ribs. The 
third and fourth ribs will be detected. The needle will target the plane 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 7 
 
between pectoralis minor and serratus muscles at the level of the third rib, 
followed by negative aspiration into the fascial plane then injection of 10 mL 
of 0.25% bupivacaine (Alshawadfy and Al-Touny, 2023). 
➢ 
In the ESPB group: - 
      The block will be performed with the patient in a sitting position 
(Costache, 2016), The high-frequency linear probe will be placed in a 
longitudinal orientation 3 cm from the midline. Once the erector spinae 
muscle and the transverse processes identified, the block needle will be 
inserted in a caudad-to-cephalad direction until the tip lay in the interfacial 
plane deep to the erector spinae muscle, 20 mL of 0.25% bupivacaine will be 
administered for block performance (Forero et al., 2016). 
• 
Intraoperative settings: 
On arrival of the patients to the operative room, ECG, non-invasive blood 
pressure, pulse oximetry will be applied with capnography during ventilation 
till extubation. Baseline parameters such as systolic blood pressure (SBP), 
diastolic blood pressure (DBP), mean blood pressure (MBP), heart rate 
(HR), and arterial oxygen saturation (SpO2) will be also recorded.  
Before surgery, 20-gauge venous access will be established in all patients, 
and infusion with 2-4 mL/kg/h ringer’s acetate solution will be started, 
general anesthesia will be induced with IV injection of fentanyl (1.5 µg/kg) 
(Plaud et al., 2020), propofol (2 mg/kg) (Gelberg et al., 2014) and 
atracurium (0.5 mg/kg) (Plaud et al., 2020) in the same sequence. 
Endotracheal intubation will be performed, controlled mechanical ventilation 
will be maintained to keep the end-expiratory carbon dioxide (CO2) values 
between 34 and 36 mmHg using capnography. Anesthesia will be maintained 
with isoflurane 1-2 MAC in 40 % oxygen in air. Incremental dose of 
atracurium (0.1 mg/kg) (Bhoi et al., 2019) will be given after assessment by 
nerve 
stimulator 
according 
to 
train 
of 
four. 
Granisetron 
3mg 
(Dehghanpisheh et al., 2022) (EM-EX® ,3mg/3ml, Amoun pharmaceutical 
company, Cairo, Egypt) will be also administered to prevent postoperative 
nausea and vomiting.  
Intraoperative fentanyl 0.5 µg/kg (Plaud et al., 2020) will be given if the 
HR or the blood pressure or both increase by >20% of the baseline. At the 
end of the procedure Isoflurane will be discontinued, neuromuscular 
blockade will be antagonized by using neostigmine 0.04 mg/kg (Choi et al., 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 8 
 
2016) plus atropine 0.01 mg/kg (Elnasr et al., 2019) after assessment by 
nerve stimulator according to train of four and will be administered to 
reverse the effect of atracurium. After extubation, all patients will be 
transferred to the post-anesthesia care unit (PACU). 
• 
Postoperative settings: 
During the first 24 hr after surgery, Postoperative pain will be evaluated 
by VAS score at 0 point (on admission to the PACU), 2, 4, 8, 16 and 24 
hours postoperatively and increments of intravenous meperidine 0.5 mg/kg 
(Friesen et al., 2016) (pethidine-HCL®, 50 mg/ml, Misr company for 
pharmaceuticals, Cairo, Egypt) will be given as a rescue analgesia at any 
time the patient feels any pain for a pain score more than 4 (maximum dose 
600 mg per day) (Friesen et al., 2016), if the patient still in pain after using 
maximum dose meperidine per day, she will be given morphine 0.1 mg/kg 
(ElGhamry and Amer, 2019) (Morphine sulphate®,10 mg/ml, Misr company 
for pharmaceuticals, Cairo, Egypt), considered block failure to be excluded 
from the study and replaced by another patient to fulfill sample size criteria. 
 In the presence of nausea, with or without vomiting, granisetron 3 mg 
(Gelberg et al., 2014) will be given IV and repeated once if nausea persisted 
(maximum dose of 6 mg per day) (Gelberg et al., 2014). 
- Complications after puncturing of the blockade (hematoma in the 
puncture sites, pneumothorax, bradycardia defined as heart rate (HR) 
<50 beats/min, tachycardia defined as HR >110 beats/min, 
hypotension defined as a decrease in mean arterial pressure (MAP) of 
>20% from the baseline value and hypertension defined as an increase 
in MAP of >20% from the baseline value) will be evaluated and well-
managed. 
➢ 
Outcome measurement: 
The age, weight, height, the American Society of Anesthesiologists 
(ASA) class of each patient will be recorded and compared among both 
groups . 
• 
Primary outcome: 
Post-operative pain severity assessed by VAS at 0 point (on admission to 
the PACU). 
• 
Secondary outcomes: 
1. Post-operative pain severity assessed by VAS at 2 hr, 4 hr, 8hr, 16 hr 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 9 
 
and 24 hr. 
2. Time of first rescue analgesia. 
3. Cumulative post-operative meperidine consumption in the first 24 
hours. 
 
➢ Statistical Analysis:  
All data will be recorded, analyzed and statistically compared between 
both groups to describe the groups and identify any significant differences 
between them. The quantitative data will be presented as mean ± standard 
deviation and range. Qualitative data will be presented as a number and 
percentage. Non-parametric data will be presented as a median and inter-
quartile range. 
 
The following tests will be done:  
• Independent samples t-test of significance will be used when 
comparing between two means.  
• Mann Whitney U test: for two-group comparisons in non-parametric 
data.  
• Chi-square (x2) test of significance will be used in order to compare 
proportions between qualitative parameters.  
• The confidence interval will be set to 95% and the margin of error 
accepted will be set to 5%. So, the p-value will be considered 
significant as the following:  
– P-value <0.05 will be considered significant.  
– P-value <0.001 will be considered as highly significant.  
– P-value >0.05 will be considered insignificant.  
➢ Statistical package:  
Recorded data will be analyzed using the statistical package for social 
sciences, version 23.0 (SPSS Inc., Chicago, Illinois, USA). 
 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 10 
 
      4. REFERENCES 
 
- 
Alshawadfy A, Al-Touny SA. Comparing the quality of analgesia with 
ultrasound-guided pectoral nerve block and serratus anterior plane block II 
in patients undergoing modified radical mastectomy: a randomised clinical 
trial. Anaesthesiol Intensive Ther 2023; 55(1):52-59. 
- 
Apfelbaum JL, Ashburn MA, Connis RT, et al. Practice guidelines for 
acute pain management in the perioperative setting: An updated report by 
the American Society of Anesthesiologists Task Force on Acute Pain 
Management. Anesthesiology 2012; 116(2):248-273. 
- 
Bakeer A, Abdallah NM. Erector Spinae Plane Block Versus PECS Block 
Type II for Breast Surgery: A Randomized Controlled Trial. Anesth Pain 
Med. 2022; 12(2): e122917. 
- 
Bakeer AH, Kamel KM, Abdelgalil AS, et al.  Modified Pectoral Nerve 
Block versus Serratus Block for Analgesia Following Modified Radical 
Mastectomy: A Randomized Controlled Trial, J Pain Res. 2020; 13:1769-
1775. 
- 
Bhoi D, Ranjitha N, Talawar P, Narasimhan P.   Ultrasound-Guided 
Midpoint Transverse Process to Pleura Block in Breast Cancer Surgery: A 
Case Report. A & A practice 2019; 12(3):73-76. 
- 
Blanco R, Fajardo M, Parras Maldonado T. Ultrasound description of 
Pecs II (modified Pecs I): a novel approach to breast surgery Rev Esp 
Anestesiol Reanim 2012; 59(9):470-475. 
- 
Blanco R. The ‘pecs block’: a novel technique for providing analgesia after 
breast surgery. Anesthesia 2011; 66(9):847-848. 
- 
Bonvicini D, Tagliapietra L, Giacomazzi A, Pizzirani E. Bilateral 
ultrasound-guided erector spinae plane blocks in breast cancer and 
reconstruction surgery. J Clin Anesth 2017; 44:3-4. 
- 
Chin KJ, Adhikary S, Sarwani N, Forero M. The analgesic efficacy of 
pre-operative bilateral erector spinae plane (ESP) blocks in patients 
having ventral hernia repair. Anaesthesia 2017; 72(4):452–60.  
- 
Choi ES, Oh AY, Seo KS, et al. Optimum dose of neostigmine to reverse 
shallow neuromuscular blockade with rocuronium and cisatracurium. 
Anaesthesia 2016; 71:443-449. 
- 
Costache I. Mid-point transverse process to pleura block for surgical 
anaesthesia. Anaesth Rep. 2019; 7(1):1-3.  
- 
Dehghanpisheh L, Azemati S, Hamedi M, Fattahisaravi Z. The effect of 
1-mg versus 3-mg granisetron on shivering and nausea in cesarean 
section: a randomized, controlled, triple-blind, clinical trial. Brazilian  
 
Journal of Anesthesiology (English Edition) 2022; 72(4):457-465. 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 11 
 
- 
Deng W, Fu D, He L. Evaluation of Pectoral Nerve Block in Modified 
Radical 
Mastectomy: 
Comparison 
of 
Three 
Concentrations 
of 
Ropivacaine. Clin Interv Aging 2020; 15:937-944. 
- 
Egypt Source: Globocan 2020.https://gco.iarc.fr/today/data/factsheets/ 
populations/818-egypt-fact-sheets.pdf 
- 
ElGhamry MR, Amer AF. Role of erector spinae plane block versus 
paravertebral block in pain control after modified radical mastectomy. A 
prospective randomised trial. Indian J Anaesth. 2019; 63(12):1008-1014. 
- 
Elnasr Awad, Amira A., Gharib, et al. Sugammadex Versus Neostigmine 
In Reversal Of Rocuronium- Induced Neuromuscular Block In Obese 
Patients. The Scientific Journal of Al-Azhar Medical Faculty, Girls 2019; 
3(1):163-171. 
- 
Forero M, Adhikary SD, Lopez H, Tsui C, Chin KJ. The erector spinae 
plane block. Reg Anesth Pain Med. 2016; 41(5):621-7. 
- 
Friesen KJ, Falk J, Bugden S. The safety of meperidine prescribing in 
older adults: A longitudinal population-based study. BMC Geriatr. 2016; 
16:100.  
- 
Gelberg J., Kongstad L., Werner O. Intubation conditions in young 
infants after propofol and remifentanil induction with and without low dose 
rocuronium. Acta Anaesthesiol Scand 2014; 58:820-825. 
- 
Livio F, Biollaz J, Burnier M. Estimation de la fonction rénale par 
l'equation MDRD: intérêt et limites pour l'adaptation des doses de 
médicaments [Renal function estimation by MDRD equation: interest and 
limitations for drug dosing]. Rev Med Suisse. 2008 ;4(181):2596-2600. 
- 
Nagaraja PS, Ragavendran S, Singh NG, et al. Comparison of 
continuous thoracic epidural analgesia with bilateral erector spinae plane 
block for perioperative pain management in cardiac surgery. Ann Card 
Anaesth 2018; 21(3):323-327. 
- 
Pani N, Sahu P, Swain D, et al. Effects of fentanyl and dexmedetomidine 
as adjuvants to bupivacaine in paravertebral block for postoperative 
analgesia in patients undergoing modified radical mastectomy: A 
prospective randomised double-blind study. Indian journal of anaesthesia 
2019; 66(4):193-199. 
- 
Pedro Solfa, Beatriz Cesar , Náira Bueno , José Alexandre. Low-dose 
midazolam for anxiolysis for pregnant women undergoing cesarean 
delivery: a randomized trial. Brazilian Journal of Anesthesiology (English 
Edition) 2022; 72(4):450-456. 
 
 
 
- 
Plaud B, Baillard C, Bourgain JL, et al. Guidelines on muscle relaxants 

 
 
Protocol For Master’s Degree Thesis / Faculty of Medicine / Ain-Shams University 
Page 12 
 
and reversal in anaesthesia. Anaesthesia Critical Care & Pain Medicine 
2020; 39(1):125-142. 
- 
Sung H, Ferlay J, Siegel RL, et al. Global cancer statistics 2020: 
GLOBOCAN estimates of incidence and mortality worldwide for 36 
cancers in 185 countries. CA Cancer J Clin 2021; 71:209-249. 
- 
Tulgar S, Selvi O, Thomas D, et al. ESRA19-0503 Erector spinae block 
in 308 patients: complications and unexpected events Regional 
Anesthesia & Pain Medicine 2019;44: A112.  
- 
Wang K, Zhang X, Zhang T, et al. The Efficacy of Ultrasound-guided 
Type II Pectoral Nerve Blocks in Perioperative Pain Management for 
Immediate Reconstruction After Modified Radical Mastectomy: A 
Prospective, Randomized Study Clin J Pain 2018; 34(4):231-236.