Comparison Of The Analgesic Effect Of Ultrasound-Guided Erector Spinae Plane Block And Ultrasound-Guided Retrolaminar Block In Patients Undergoing Video Assisted Thoracoscopic Surgery: A Prospective, Randomized Study.
Phase: NA
Conditions: Post-operative Analgesia, Retrolaminar Block, Erector Spinae Plan Block, VATS
Sponsor: Cairo University

11/12/2022 
  
Comparison Of The Analgesic Effect Of Ultrasound-Guided Erector Spinae Plane 
Block And Ultrasound-Guided Retrolaminar Block In Patients Undergoing Video 
Assisted Thoracoscopic Surgery: A Prospective, Randomized Study. 
      
 
 
 
 

 
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Table of Contents 
 
Title Page ...................................................................................................................................................... 2 
Study Title ................................................................................................................................................. 2 
Investigators .............................................................................................................................................. 2 
Introduction: .................................................................................................................................................. 3 
Aim of the work ............................................................................................................................................ 4 
Objectives: .................................................................................................................................................... 4 
Hypothesis .................................................................................................................................................... 4 
Ethical Considerations .................................................................................................................................. 4 
Methodology ................................................................................................................................................. 5 
I. 
Study design ...................................................................................................................................... 5 
II. 
Study setting and location ................................................................................................................. 5 
III. 
Study population ........................................................................................................................... 5 
IV. 
Eligibility Criteria ......................................................................................................................... 5 
1. 
Inclusion criteria ........................................................................................................................... 5 
2. 
Exclusion criteria .......................................................................................................................... 5 
V. Study Procedures .............................................................................................................................. 6 
1. 
Randomization (in RCT only)....................................................................................................... 6 
2. 
Study Protocol ............................................................................................................................... 7 
3. 
Measurement tools ...................................................................................................................... 10 
VI. 
Study outcomes ........................................................................................................................... 10 
1. 
Primary outcome ......................................................................................................................... 10 
2. 
Secondary outcome(s) ................................................................................................................. 10 
Statistical Analysis ................................................................................................................................. - 12 - 
I. 
Sample size ................................................................................................................................ - 12 - 
II. 
Statistical analysis ...................................................................................................................... - 12 - 
References ................................................................................................................................................... 14 
 
 
 

 
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Study Title 
COMPARISON OF THE ANALGESIC EFFECT OF ULTRASOUND-
GUIDED ERECTOR SPINAE PLANE BLOCK AND ULTRASOUND-
GUIDED RETROLAMINAR BLOCK IN PATIENTS UNDERGOING 
VIDEO ASSISTED THORACOSCOPIC SURGERY: A PROSPECTIVE, 
RANDOMIZED STUDY. 
Investigators 
Candidate Details 
Name: Islam Mohamed Sayed Mahmoud 
Degree: MD 
Affiliation: assistant lecturer at Anesthesia, surgical ICU and Pain management 
department 
Phone No: 002-01008039448                           Email: sharr866@gmail.com  
Principle Investigator 
Name and Affiliation: Prof. Dr. Maged Salah Mohamed. 
Phone No:  002-01223938564                       Email: Maged.salah@kasralainy.edu.eg 
Co-investigator (A): 
Name&Affiliation: Assistant prof. Dr. Dina Soliman Mohamed Idris. 
Phone No: 002-01221055531                        Email: deenasoli2000@yahoo.com 
Co-investigator (B): 
Name&Affiliation: Dr. George Eshak Loza Abdel Malek. 
Phone No:  002- 01001904240                      Email: georgemalek74@gmail.com 
   Co-investigator (C): 
Name&Affiliation: DR. Mohamed Ramadan Ahmed. 
Phone No:  002- 01004004580                    Email: dr.moh.ramadan.48@gmail.com 
 
 

 
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Introduction: 
 
       Video-assisted thoracoscopic surgery (VATS) is increasingly being used to 
manage primary lung cancer and helps reduce postoperative pain. However, it is a 
fact that pain following VATS can be severe and long-lasting. According to 
Takahiro Homma et al., 18.8% of patients who undergo VATS present with 
persistent pain 2 months after surgery (1–3).The provision of pain relief is a 
significant consideration, and thoracic epidural analgesia is often regarded to be the 
gold standard. (4) However, epidural analgesia is not always ideal, and other 
practical regional methods of analgesia after VATS  have been proposed as Erector 
Spinae Plane Block (ESPB) or retrolaminar block (RLB) . (5) 
      The retrolaminar block (RLB), which was first introduced by Pfeiffer et al.(6), 
is a modified paravertebral block that administers local anesthetic between the 
lamina of the thoracic vertebra and the erector spinal muscles, using landmark 
technique or under ultrasound guidance. (6) Previous clinical study by Wang, Q., 
Wei, S., Li, S. et al. reported that RLB provides a good analgesic effect after VATS 
but was inferior to paravertebral block(PVB)(7). 
    Erector spinae plane block (ESPB) is a relatively new interfascial block procedure 
first described for thoracic analgesia. Previous clinical studies reported that ESPB 
provides a good analgesic effect after VATS (comparable with PVB)(8) and 
decreases morphine consumption after Lateral thoracotomy surgery (9,10). Thus, 
anesthesiologists now have a greater choice for regional anesthesia for thoracic 
analgesia. Although ESPB and RLB have similar puncture sites, Only one clinical 

 
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study comparing ESPB and RLB in breast surgery has been reported  (11), The 
mentioned study was also limited only to female patients. both blocks were 
compared with PVB(7,8) but There is no clinical study that compares ESPB and 
RLB directly in VATS. Although the mechanisms of action of both ESPB and RLB 
have not yet been completely clarified, one cadaveric study indicated that ESPB 
leads to a broader spread of the local analgesic into a more extensive range of 
intercostal spaces from a single point of injection than RLB (12). Another cadaveric 
study reported that the lateral pathway, which is involved in the blockade of the 
intercostal nerve or the lateral cutaneous branches of the intercostal nerves, is the 
primary mechanism of ESPB, in contrast to RLB (13,14).  
       Based on these anatomical studies, we hypothesize that ESPB can be superior 
to RLB for postoperative analgesia after VATS.  
Aim of the work 
     This prospective, randomized, controlled clinical trial aims to compare the 
analgesic efficacy of ESPB and RLB after VIDEO ASSISTED THORACOSCOPIC 
SURGERY. 
Objectives: 
 To compare the efficacy of ESPB and RLB after VATS. 
 As regards: 
 Hemodynamics  
 Postoperative pain 
 Postoperative analgesic requirements 
Hypothesis: 

 
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  We hypothesize that ESPB can be superior to RLB for postoperative analgesia 
after VATS. 
Ethical Considerations 
   The study will be conducted after obtaining approval from the institutional research 
and ethics committee. Written informed consent will be obtained from all 
participants. 

 
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Methodology 
 
I. 
Study design    
A prospective randomized, double-blind controlled study 
II. 
Study setting and location 
Cairo University Hospitals, Cardiothoracic, and Vascular Anesthesia Unit 
III. 
Study population 
    The study will be conducted on patients undergoing VATS. 
IV. 
Eligibility Criteria 
Inclusion criteria 
1. The age range of 18-75 years.  
2. American Society of Anesthesiologists physical status class (ASA) I, II 
and III 
3. Patients undergoing VATS. 
4. Patients Gender eligible for the study: both  
Exclusion criteria  
1- Patient refusal 
2- Coagulopathy, bleeding disorders, 
3-  In-ability to postpone anti-coagulation medications. 
4-  infection at the injection site 
5- pregnancy, breastfeeding, 

 
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6- severe obesity (body mass index > 35 kg/m2 ) 
7- allergy to any drug used in the study 
8-  preoperative daily use of a non-steroidal anti-inflammatory drug 
(NSAID) or opioids, 
9- Previous surgery in the thoracic vertebral region  
10- 
Liver dysfunction.  
11- 
 Injury or a lesion at the block site. 
V. 
Study Procedures 
 Patients will be randomly allocated into two equal groups: 
Group I (E): Will receive a US-guided ESPB 
Group II (R): Will receive a US-guided RLB 
VI. 
Randomization and Blinding  
      Patients will be randomized using a computer-generated list of random 
numbers, which will be sealed in closed envelopes. Patients will be randomly 
allocated to one of two groups; Group I (E) will receive a US-guided ESPB, 
while Group II (R) will receive a US-guided RLB. An anesthesiologist who 
is not involved in the data collection team will perform all nerve blocks. Intra- 
and postoperative data will be collected by an anesthesiologist or intensivist 
who is blinded to the study protocol. 
 
 
Study Protocol 
 
1- Preoperative assessment  

 
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               Following approval from Research Committee of Anesthesia 
Department and the Ethics Committee of the Faculty of Medicine, Cairo 
University, 44 patients will be included in the study (22 patients per group). 
After obtaining written informed consents, all patients will be subjected to 
systematic preoperative assessment including history taking, physical 
examination, and review of the results of routine investigations. Upon arrival 
to the preparation room, a 20G IV cannula will be inserted into a peripheral 
vein and midazolam 2-3 mg will be administered unless contraindicated. A 
20G arterial catheter will be inserted into the radial artery of the dependent 
(non-operative) side, after local infiltration with lidocaine 2%. 
2- Intraoperative management:  
Patients will be transferred to the operating room where routine monitoring is 
applied, including electrocardiography (ECG), invasive Blood Pressure (IBP) 
and pulse oximetry are attached. Baseline heart rate, blood pressure, oxygen 
saturation and respiratory rate will be recorded. 
      Subsequently, either ultrasound-guided ESPB or RLB will be performed 
according to group allocation. Both blocks will be executed using a 3 to 12.0-
MHz linear array transducer (Linear Ultrasound Transducer Probe L12-3 For 
Philips) connected to an ultrasound imaging system (Philips HD11XE) by an 
experienced anesthesiologist skilled in performing both ESPB and RLB. 
Patients will be positioned in the sitting position.  
 Patients allocated to Group I: Will receive a US-guided ESPB before 
the start of the surgery. 
 Patients allocated to Group II: Will receive a US-guided RLB before 
the start of the surgery. 

 
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Under aseptic precautions, the ultrasound transducer will be placed on the 
patient’s back in a longitudinal paramedian orientation approximately 3 cm 
(ESPB) or 1 cm (RLB) from the midline. A short-bevel, 80 mm 22-gauge 
insulated nerve block needle will be inserted using an in-plane approach to 
contact the tip of either the T4 transverse process for ESPB Or the T4 lamina of 
the vertebra for RLB, After negative aspiration of blood, a total of 20 mL of 
0.25% bupivacaine(15) will be injected through the needle. Adequacy of the 
block will be confirmed by ultrasonographic visualization of fluid spread (seen 
as a lifting of the erector spina muscles in both block) and after 15 min, 
documenting the sensory blockade will be done by using a piece of ice or cold 
object. If the desired sensory level fails to be achieved (T4 – T8), patients will be 
excluded from the study.  
.  
  Anesthesia will be then induced with Propofol 2–3 mg/kg, together with 
fentanyl 2 mg/kg until loss of verbal response. Muscle relaxation will be achieved 
with atracurium 0.5 mg/kg and the patient’s trachea will be intubated using a 
double-lumen tube, as indicated by the surgical procedure. Anesthesia will be 
maintained by isoflurane, and muscle relaxation will be maintained with 
atracurium 0.3 – 0.5 mg/kg/hr. 
The lungs will be ventilated with positive pressure ventilation to maintain end-
tidal carbon dioxide (EtCO2) between 32 and 36 mmHg. 
Acetaminophen (1gm) will be intravenously administered 90 min after the block 
procedure in both groups. As for their routine procedure, the surgeons will not 
perform local anesthetic wound infiltration at all. 
Patients’ heart rate and blood pressure (systolic, diastolic, and mean arterial blood 
pressure) will be monitored continuously and recorded at ten-minute intervals 
until the end of surgery. Any attack of hypotension, defined as a drop of > 20% 
of baseline blood pressure, will be managed by ephedrine 0.2 mg/kg IV, and 

 
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administering I.V. fluids. On the other hand, hypertension, defined as an increase 
of > 20 % of baseline blood pressure, will be managed by increasing the depth of 
anesthesia and administering bolus doses of fentanyl 1 mic/kg (up to 3 mic/kg 
maximum dose). Bradycardia (heart rate < 50 beats/min) will be managed by 
atropine 0.02 mg/ kg IV  
 At the end of surgery residual neuromuscular blockade will be reversed and the 
endotracheal tube will be removed.     
Postoperative management:  
Patients will be transferred to the ICU and will be monitored for 24 hours where 
all patients will receive a standard 1 gm. of IV Acetaminophen every 6 hours. 
Patients’ heart rate, blood pressure, oxygen saturation, respiratory rate and the 
pain score using visual analogue scale will be monitored at regular intervals of 4 
hours over the duration of 24 hours. A VAS equal to or more than four will 
necessitate administering rescue doses of Morphine (0.05 mg/kg). The number 
of patients requiring rescue analgesia, the total dose of Morphine, and the elapsed 
time from the block procedure until the administration of the first postoperative 
rescue analgesic will be recorded. 
VII. 
Measurement tools 
 Hemodynamic parameters:  Arterial blood pressure (systolic, diastolic, and mean) 
                               HR 
 VAS 
 Time for the first rescue analgesia 
 Total analgesic consumption 

 
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VIII. 
Study outcomes 
1. Primary outcome 
Total amount of morphine consumption in the first 24-hour postoperative in the 
two groups  
2. Secondary outcome(s) 
 Time is required to perform the technique (between the start of US scanning 
and the local anesthetic injection). 
 Hemodynamic parameters: 
HR 
Arterial blood pressure (systolic, diastolic, and mean) 
Hemodynamic parameters will be measured 15 minutes after blocks are done 
before the induction (baseline), immediately after intubation, every 10 
minutes intraoperative, immediately after extubation, and every 4 hour in the 
ICU for the first 24 hours. 
 Intraoperative cardioactive drug use: 
The number of patients requiring ephedrine and atropine. 
 Intraoperative analgesics: 
The number of patients requiring additional doses of fentanyl.  
Total intraoperative IV fentanyl dose (above the standard two µg/kg). 
 Pain score: 

 
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VAS value obtained from the patient immediately after recovery 
from anesthesia then every 4 hours during the first 24 hours 
postoperatively. 
 Postoperative analgesics: 
                     The elapsed time from the block procedure until the 
administration of the first postoperative rescue analgesia 
. 
 Incidence of side effects related to opioid use (postoperative nausea and 
vomiting (PONV), constipation, pruritus, urinary retention) in postoperative 
time. 
 Incidence of complications or side-effects related to the block (bradycardia, 
hypotension, hematoma formation or intravascular injection). 
 
Statistical Analysis 
I. 
Sample size 
      Our analysis will be performed using G power software on the level of 
total amount of morphine consumption in the first 24-hour postoperative as 
it is the primary outcome in the current study using a student t-test. 
A previous study showed that total amount of morphine consumption in the 
first 24-hour postoperative after VATS , mean(SD) after ESPB was 
20.6046(7.9398) mg .(9) this was calculated from median and range based 
on Lou et al (16) and Wan et al (17). 

 
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Based on assumption that a 30% difference between groups is a clinically 
significant difference and for a power of 0.95 and alpha error of 0.05. 
A minimum of 20 patients was calculated for each group. The sample size 
will be increased to 22 for each group to compensate for possible dropouts. 
Statistical analysis 
          Data analysis will be performed using Statistical package for social 
science (SPSS) software, version 15 for Microsoft Windows (SPSS Inc., 
Chicago, iL, USA). Categorical data will be reported as numbers and 
percentages and analyzed using the chi-squared test. Continuous data will be 
checked for normality using the Kolmogorov-Smirnov test. Normally 
distributed data will be presented as means (standard deviations) and analyzed 
using an unpaired student t-test. Skewed data will be expressed as medians 
(quartiles) and analyzed using the Mann-Whitney U test. For repeated 
measures, a two-way repeated-measures ANOVA will be used to evaluate the 
block (between-groups factor) and the time (repeated measures)". Post-hoc 
pairwise comparison will be performed using the Bonferroni test. A P-value 
of 0.05 or less will be considered significant. 
 
 
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