Comparative Study of the Effect of Continuous Caudal Epidural With General Anaesthesia Versus General Anaesthesia on Intra Operative and Post Operative Analgesic Requirements for Lumbar Fixation
Phase: NA
Conditions: Analgesia
Sponsor: Ain Shams University

 
 
 
 
 
 
 
Official title 
 
Comparative study of the effect of continuous caudal 
epidural with general anaesthesia versus general 
anaesthesia on intra operative and post operative 
analgesic requirements for lumbar fixation 
 
 
 
DOCUMENT DATE: 
APRIL 9, 2025 
 
 
protocol 
 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
Page 1 
 
 
  
 
 
Comparative study of the effect of continuous caudal 
epidural with general anaesthesia versus general 
anaesthesia on intra operative and post operative 
analgesic requirements for lumbar fixation 
   
Thesis  
Submitted for Partial Fulfillment of M.D. Degree  
in Anaesthesiology, Intensive Care and Pain Management 
 
By  
Postgraduate Student: Esraa Abd El-Latif Mohamed Shawky  
    Degree: M.B.B.CH., M.Sc., (Ain-Shams University) 
 
Under Supervision of  
DIRECTOR: Dr. Mahmoud Abd El-Aziz Ahmed Ghallab 
  Academic Position: Professor of Anaesthesia, Intensive Care and Pain 
Management, Faculty of Medicine, Ain Shams University 
 
CO-DIRECTOR: Dr. Ahmed Mohamed El-Sayed El-Hennawy 
Academic Position: Professor of Anaesthesia, Intensive Care and Pain 
Management, Faculty of Medicine, Ain Shams University 
 
CO-DIRECTOR: Dr. Paula Micheal El-Komos Samaan  
Academic Position: Lecturer of Anaesthesia, Intensive Care and Pain 
Management, Faculty of Medicine, Ain Shams University 
 
CO-DIRECTOR: Dr. Omar Mohamed Zafer Mohamed  
Academic Position: Lecturer of Anaesthesia, Intensive Care and Pain 
Management, Faculty of Medicine, Ain Shams University 
 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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Faculty of Medicine 
 Ain Shams University 
               2023 
What is already known on this subject? AND 
What does this study add?  
Caudal epidural anaesthesia has been used successfully in adult patients either as 
primarily sole anaesthetic technique or adjuncts to general anaesthesia to provide 
post operative analgesia. Pre-emptive caudal epidural is a proven technique for 
providing analgesia for spinal surgeries. Challenging aspect of spine surgery is to 
provide extended post operative analgesia. 
This study is designed to evaluate the effectiveness of continuous caudal epidural 
for intra operative analgesia as alternative to opioid analgesia in general anaesthesia 
and reducing post operative opioid requirements to control post operative pain. 
 
1. INTRODUCTION/ REVIEW  
Pain control during intra operative and post operative period for spine surgeries 
is crucial in patients as poor pain control may result in morbidity and mortality 
(Fawzi &Almarakbi, 2012). Severe acute pain prolongs hospital stay, delays 
mobilization and promotes subsequent chronic post-surgical pain (Schug &Bruce, 
2017). 
Whilst general anaesthesia is commonly used to undertake spine surgery, the use 
of neuraxial and peripheral regional anaesthesia techniques for intra operative and 
post operative analgesia is an evolving practice (Gerbershagen et al., 2013). 
Multimodal analgesia, including opioids, is used to limit pain after spinal surgery. 
Common adverse effects of opioids include nausea, constipation, ileus, delirium, 
itching, respiratory depression and respiratory tract infection (Eochagain et al., 
2022).  
Caudal anaesthesia was described in 1901 by two French physicians, Fernand 
Cathelin and Jean-Anthanase Sicard (Waurick & Waurick, 2015). The caudal 
epidural block was first introduced as a landmark-based, blind technique. Success 
rate in adults was 68–75% even in the experienced hands. Because of the inaccuracy 
of blind technique, some authors have recommended that caudal epidural injection is 
performed under fluoroscopic guidance (Barham &Hilton, 2010). Continuous 
caudal analgesia was first applied clinically, in 1941, being used to relieve pain for an 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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operation upon the lower extremity (Kao & Lin, 2017). Caudal epidural 
anaesthesia/analgesia is the most widely employed technique for various surgical 
procedures within the distribution of T10–S5 dermatome and it is easier to perform 
caudal procedure in the prone position (Hurley, 2010). 
Caudal analgesia is a good, reliable and easy method to provide intra operative 
and post operative analgesia. However, the single shot caudal analgesia is short in 
duration, so the catheter injection may be used to prolong the analgesia time as 
continuous caudal epidural (El-Feky &Abd El Aziz, 2015).  
 Caudal epidural analgesia, as pre-emptive analgesia, is an underutilized 
technique in adult patients undergoing lumbosacral spine surgeries. Caudal epidural 
block before surgery acts by blocking sensory input at the spinal cord level. Thus, 
pre-emptive analgesia has an important role in providing effective pain relief after 
lumbosacral spine surgeries (Al Oweidi et al., 2010). The combined caudal epidural 
analgesia with general anaesthesia is a proven technique in providing analgesia and 
managing post operative pain in lumbar spine procedures (Lakshminarasimhaiah G 
et al., 2018). It provides prolonged pain relief with adequate sensory block and 
limited motor blockade for early mobilization (Nagappa et al., 2018). 
Among all available local anaesthetic bupivacaine is most commonly used. It 
produces a denser sensory block and enables better control of sensory and motor 
blockade while having the least incidence of an incomplete block (Benyahia et al., 
2015). 
Common complications associated with caudal anaesthesia include: Subdural, 
intravascular, or intraosseous injection, infection, hypotension, nerve roots injury, 
rectum perforation, hematoma formation, local anaesthetic toxicity, delayed 
respiratory depression, urinary retention, sacral osteomyelitis (Wiegele et al., 2019). 
A devastating complication of a caudal block is total spinal anaesthesia that can 
occur from an inadvertent dural puncture with subsequent intrathecal injection of 
local anaesthetic. Also, caudal epidural blocks have a higher incidence of local 
anaesthetic-related seizures (Schug & Bruce, 2017). 
The overall benefit of intravenous analgesia versus caudal analgesia is still 
controversial, although many studies have shown that caudal epidural analgesia 
provides superior post operative analgesia compared to intravenous analgesia 
(Kumar et al., 2017). 
In this clinical study, we will justify the current practice of combined continuous 
caudal epidural with general anaesthesia in adult patients undergoing lumbar fixation 
versus general anaesthesia. Furthermore, we will determine the analgesic 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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requirement, rescue analgesia, hemodynamic changes and possible complications 
with continuous caudal epidural analgesia. 
 
2. AIM/ OBJECTIVES  
The aim of this study is to evaluate the effectiveness of combined continuous 
caudal epidural with general anaesthesia versus general anaesthesia for intra 
operative and post operative analgesia in patients undergoing lumbar fixation, by 
recording intra operative and post operative analgesic requirements, blood pressure 
and heart rate and post operative patient-reported pain on the numeric pain scale score. 
 
3. METHODOLOGY: 
Patients and Methods  
- Type of the study: Interventional, prospective, comparative randomized 
clinical trial. 
- Study Setting: The operating theaters of Ain Shams University Hospitals. 
- Study period: Over six months, after the approval of Medical Research 
Ethical Committee. 
- Study population: 
Inclusion criteria: 
- Age group: Adult patients from age of 21 years to 60 years  
- Sex: Both sexes. 
- ASA Classification: patients with ASA classification I, II. 
- Elective lumbar fixation surgeries. 
Exclusion criteria: 
- Patients refuse to give informed consent. 
- Patients younger than 21 or older than 60. 
- History of bupivacaine allergy. 
- Emergency surgeries. 
- Patients who underwent previous spine surgeries of any cause. 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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- Infection at the site of injection.  
- Coagulopathy (acquired, induced, genetic). 
- ASA Classification: ASA III, IV. 
- Severe aortic stenosis, severe mitral stenosis, hypertrophic obstructive 
cardiomyopathy. 
- Severe hypovolemia, Severe uncorrected anemia. 
- Increased intra-cranial pressure (i.e., brain tumor or recent head injury). 
 
Sampling method: 
Patients will be randomly allocated by computer generated randomization into two 
equal groups A and B. 
- Group A: Patients doing lumbar fixation with combined continuous caudal 
epidural and general anaesthesia.  
- Group B: Patients doing lumbar fixation under general anaesthesia (opioid 
analgesia). 
 
Sample size justification: 
       Using PASS 15 program for sample size calculation and according to 
(Abdelhady et al., 2022), the expected mean intra-operative narcotic consumption 
among study groups is 186.5 ± 21.6 µg and 106 ± 16.4 µg. 
Sample size of 30 patients per group can detect the difference between two 
groups with power >90% and alpha error 0.05. 
 
 
Ethical considerations: 
 
The study protocol will receive ethical approval from the Medical Research 
Ethical Committee, Faculty of Medicine, Ain Shams University. Informed written 
consent will be obtained from each patient before patients' allocation. 
Study Procedures: 
         Patients will be randomly allocated into two equal groups. 
 
Preoperative setting:  
- Pre-operative assessment will be done by accurate history taking, full physical 
examination, laboratory and radiological investigations. including complete 
blood count (CBC), liver function test (LFT), kidney function test (KFT), 
prothrombin time (PT) and partial thromboplastin time (PTT) will be checked. 
- All patient will be fasting for 8 hours pre operative.  
- All patients will be informed about the study design, objectives and 
techniques.  

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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- Informed consent will be signed by every patient prior to inclusion in the 
study.  
- All patients will be educated about numeric pain scale score which 0 means no 
pain and 10 means worst imaginable pain. 
 
Intraoperative setting:  
- Standard 
perioperative 
monitoring 
will 
include 
pulse 
oximetry, 
electrocardiogram, end-tidal CO2 measurement, inhaled volatile agent 
concentration and non-invasive blood pressure measurement. 
- Baseline parameters such as oxygen saturation, systolic, diastolic and mean 
blood pressure, heart rate will be observed. 
- Intravenous line will be inserted. 
- For all patients, general anaesthesia will be induced by intravenous route using 
midazolam 0.04 mg/kg, fentanyl 1 µg/kg, propofol 2 mg/kg, atracurium 0.5 
mg/kg.  
- This will be followed by endotracheal intubation and mechanical ventilation. 
Maintenance of anaesthesia will be achieved by isoflurane 1.5% in oxygen and 
air (50:50) and atracurium 0.1 mg/kg every 20 minutes, so as to maintain end 
tidal CO2 between 35 to 40 mm Hg. 
- Intra operative heart rate and mean blood pressure will be recorded. Estimated 
blood loss will be determined. 
 
Group A: (continuous caudal epidural with general anaesthesia “study group”)  
- After induction of anaesthesia as mentioned above, patients will be located in 
the prone position for caudal epidural block. Sterile skin preparation and 
draping of the entire region will be completed in the standard fashion. 
- Fluoroscopy will be utilized and a lateral view will be obtained to demonstrate 
the anatomic boundaries of the sacral canal. With fluoroscopy, the caudal 
canal will appear as a translucent layer posterior to the sacral segments. The 
median sacral crest will be visualized as an opaque line posterior to the caudal 
canal. The sacral hiatus will be visualized as a translucent opening at the base 
of the caudal canal. The coccyx will be seen articulating with the inferior 
surface of the sacrum. A 17- or 18-gauge Tuohy-type needle will be inserted in 
the midline into the caudal canal. A feeling of a slight “snap” may be 
appreciated when the advancing needle pierces the sacrococcygeal ligament. 
Once the needle reaches the ventral wall of the sacral canal, it will be 
withdrawn and reoriented, directing it more cranially (by depressing the hub 
and advancing) for further insertion into the canal. The anteroposterior view 
will be used once the epidural needle is safely situated within the canal and the 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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epidural catheter will be advanced cephalad. In this projection, the 
intermediate sacral crests will appear as opaque vertical lines on either side of 
the midline. The sacral foramina will be visualized as translucent and nearly 
circular areas lateral to the intermediate sacral crests. Once the correct 
placement of the needle will be confirmed, a catheter will be inserted into the 
desired location while depth and position will be confirmed fluoroscopically. 
- Before the local anaesthetic will be injected, careful aspiration or passive 
drainage is essential to exclude an unintentional intravascular or intrathecal 
needle location. An initial dose of 20 ml of 0.25% bupivacaine will be injected 
in the caudal canal in order to perform sensory block and spare motor power. 
Then a dose of 10 ml 0.25% bupivacaine will be injected through the epidural 
catheter every 1-hour intra operatively and at 0-hour and 1-hour post 
operative. Then the catheter will be removed 1 hour post operative. 
Group B: (general anaesthesia “control group”) 
- General anaesthesia will be induced as described above with administration of 
extra doses of fentanyl as needed according to hemodynamic changes 
suggesting pain sensation. 
 
 
Post-operative setting:  
- After completion of surgery, the residual neuromuscular block will be reversed 
with injection of neostigmine 0.05 mg/kg and atropine 0.01 mg/kg. When 
patients become suitable for extubation, with stable hemodynamic and 
adequate muscle power, thorough oral and endotracheal suction followed by 
extubation will be done. 
- Patients will be nursed in post anaesthesia care unit for monitoring of post 
operative vital signs and for post operative pain assessment by numeric pain 
scale score at 0-hour and management accordingly. 
- Patients postoperative pain will be followed up at the ward at time interval 0, 
1, 2, 4, 6 hours. 
- Patients will undergo close monitoring for the first 6 hours after caudal 
injection for overdose or adverse reactions. 
 
- The following factors will be assessed: 
(1) Intra operative heart rate and blood pressure. 
(2) Post operative pain assessment according to numeric pain scale score 1-
10 as (0= no pain, 10 =worst imaginable pain) and hemodynamic 
parameters at 0, 1, 2, 4, 6 hours. 
(3) Time to rescue analgesia (intravenous analgesia administered after 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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surgery) when the numeric pain scale score is 3 or higher. Patients with 
numeric pain scale score ≥ 3 at any point of time, will receive 
intravenous morphine 5mg. 
(4) Estimated blood loss and surgeon satisfaction of surgical field. 
(5) Total intra operative and post operative analgesia in both groups. 
(6) Common complications of caudal block in the postoperative period 
which include hypotension, bradycardia, lower limb numbness and 
urinary retention. These complications will be recorded and managed 
accordingly. 
 
Measured outcomes: 
Primary outcome: 
- Determining the total amount of fentanyl that will be consumed as intra 
operative analgesia. 
 
 
Secondary outcome: 
- Determining the total amount of morphine that will be given as analgesia for 
the first 6 hours post operative. 
- Analyzing the numeric pain scale score for the first 6 hours post operative. 
- Detecting effect of continuous caudal epidural analgesia on intra operative and 
post operative hemodynamic changes. 
- Identifying the time to the first demand for rescue analgesia. 
- Justifying the use of continuous caudal epidural for analgesia in lumbar 
fixation surgeries. 
 
 
Statistical analysis: 
● Statistical analysis will be carried out using the statistical software SPSS 
program. Description of quantitative data as mean and standard deviation and 
qualitative data as number and percentage. 
● Comparison between the two groups will be done by using the Chi-square test, 
independent t-test or Mann–Whitney U-test according to the distribution of 
data. A p-value less than 0.05 will be considered statistically significant.  
 
End point:  
- Severe hemodynamic instability due to any surgical complication. 
- Any surgical emergency that will need to reopen the patient in operating 
room. 

M.D.’s degree Thesis /Faculty of Medicine/ASU/2023 
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- 6 hours post operative. 
 
 
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