Comparative Analysis of Intraoperative Effect Dexmedetomidine and Fentanyl as an Adjuvant to Heavy Bupivacaine in Spinal Anaesthesia in Lower Limb Orthopedic Surgeries.
Phase: PHASE4
Conditions: Spinal Anesthesia Duration
Sponsor: Nashwa Ahmed

Comparative analysis of intraoperative effect dexmedetomidine and 
fentanyl as an adjuvant to heavy bupivacaine in spinal anaesthesia in 
lower limb orthopedic surgeries 
 
Background 
Spinal anesthesia is the most widely employed procedure for lower limb 
orthopaedic operations, as it is very cost-effective and simple to apply. These 
advantages can be restricted because presently existing local anesthetic drugs 
have relatively short length of action.  (1) 
Spinal anesthesia with 0.5% heavy bupivacaine (hyperbaric) is a common 
technique, still there is burden of its short duration of action. To overcome this 
issue, there is a continuous search for an ideal adjuvant.(2)  Adjuvants are mostly 
added to local anesthetic drugs to increase their effectiveness,  speedy onset, 
increase the period of the block, and reduce the local anesthetics dosage, thus 
reduction their adverse effects.(3) Such adjuvants had been beneficial in extension 
of analgesia  along with initiation of  movement though their related side 
effects.(4) 
Administration of opioids intrathecal such as fentanyl, morphine, and 
buprenorphine, allows decrease dose of the local anesthetic drug, augment 
analgesic effectiveness, and reduces probable toxicity and cardiovascular adverse 
consequences of local anesthetics. (5, 2)  
 Nevertheless, adverse effects such as possibly disastrous delayed respiratory 
depression, urinary retention, nausea, pruritus, vomiting, and constipation have 
provoked further study to investigate non opioid analgesic drugs with less 
troublesome drawbacks. (6,2,7,8) 
Dexmedetomidine is a novel central alpha2-agonist that was approved by the 
FDA in 1999.It has sedation, anxiolytic, analgesic and sympatholytic effect that 
depress cardiovascular reflexes in perioperative interval. (2) 
Thus, this study will be conducted for assessment of the effectiveness of addition 
4 µg Dexmedetomidine to hyperbaric Bupivacaine intrathecally in lower limb 
orthopaedic surgeries. 
Aim 
This clinical comparative study aiming to evaluate the hemodynamic stability and 
onset and duration of motor block of using intrathecal dexmedetomidine and 
fentanyl as an adjuvant to heavy bupivacaine in lower limb orthopaedic surgeries. 

Patients and Methods 
After approval of medical institutional ethical committee, 40 patients of 
American Society of Anaesthesiologists (ASA) physical status 1or 2, aged 
between 20-60 years will be incorporated in this prospective randomized 
controlled study. 
Inclusion Criteria 
1. The patient aged range from 20 to 60 years  
2. ASA 1 and 2  
3. Patient prepared for elective lower limb orthopaedic surgeries.   
4. Height 150-180 cm.  
5. Weight 50-70 kg. 
6- Either sex male or female. 
Exclusion Criteria   
1- Patient refusal.   
2- Patient has absolute contraindication to spinal anaesthesia. 
3-Patients with neurological disorders, pregnancy, local infection at the site of 
injection  
4- Patients suffering from dysrhythmia or heart block. 
5- Patients with ASA 3 or more. 
An informed written consent will be taken from all the contributors.   
Patients will be divided into the following groups using randomizer software. 
 Group D: patients will receive 3 mL volume of 0.5% hyperbaric bupivacaine and 
4 µg dexmedetomidine in 0.5 mL of normal saline intrathecal (dexmedetomidine 
100 µg/mL will be diluted in 12.5 ml preservative-free normal saline, 0.5 ml will 
be withdrawn)   
Group F: patients will receive 3 mL volume of 0.5% hyperbaric bupivacaine with 
25 µg fentanyl (0.5 mL) intrathecal.  
Anesthetic technique  
• Patients will be moved to operation table, 18G IV access is inserted and 
secured. 

• Preloading begin15minutes before spinal anaesthesia administration with 
ringer lactated 20ml /kg. 
• Intraoperative monitoring involves NIBP, pulse rate, ECG, SPO2. 
• Patients will be divided randomly into two groups by using randomizer    
software.   
•  Baseline vital signs will be measured.   
Under strict aseptic technique, after the local infiltration with 2% lignocaine, 
lumbar puncture is done using 25 G Quincke spinal needle, at L 3 - L 4 space 
after free flow of csf is verified. Instantly after spinal injection, the patient is 
placed in a supine position with a cushion supporting shoulders and head.  O2 (4-
6L/min) is provided throughout face mask. 
The following parameters will be measured: 
Intraoperative measurement will be collected from the time of intrathecal 
administration to transfer to the recovery room. 
➢  Intraoperatively non-invasive blood pressure and heart rate will be 
documented, every 15 min for first 30minutes then every 30 min till the end of 
the surgery.  
➢ onset time of bromage 3 motor block will be recorded (Onset of the motor 
block; period between the ending of intrathecal drug injection and entire motor 
paralysis)  
➢ Duration of motor block will be evaluated by the time taken to return from 
complete Bromage motor block (bromage 3) to scale 0. 
Motor block is evaluated with Modified Bromage scale (6) 
Bromage 0: The patient can move the hip, knee and ankle.  
Bromage 1: The patient can’t move the hip but has ability to move the knee and       
ankle.  
Bromage 2: The patient can’t move the hip and knee but has ability to move the 
ankle.  
Bromage 3: The patient can’t   move the hip, knee and ankle. 
➢ Complications will be noted Intraoperative  
▪  nausea, vomiting, pruritis.   
▪ Hypotension (> 20% fall of baseline blood pressure or systolic blood 
pressure of <100mmHg.) will be treated with bolus dose of 6 mg ephedrine 
IV 

▪ Bradycardia (pulse rate < 60 bpm), will be treated with 0.3- 0.6 mg atropine 
IV  
▪ Incidence of respiratory depression defined as respiratory rate less than 9 
/min and SpO2 less than 90% on room air, will be noted, it will be treated 
with Oxygen (2 L/min), will be administered via a mask 
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