Comparative Study of two Doses of Intrathecal Dexmedetomidine Versus Fentanyl as Adjuvant to Hyperbaric Bupivacaine Spinal Anesthesia

Abstract

The aim of this study was to evaluate the effect of addition two different doses of dexmedetomidine or fentanyl to intrathecal hyperbaric bupivacaine on spinal block characteristics, intraoperative hemodynamics, the blood glucose level and postoperative pain. 100 patients ASA I and II, ages 20 -60 years old undergoing elective surgeries below the umbilicus under spinal anesthesia were divided into four groups (n=25 each): Patients were randomly allocated into four equal groups (n= 25, each): Group I: received 3 mL of 0.5% hyperbaric bupivacaine +0.5ml normal saline. Group II: received 3 mL of 0.5% hyperbaric bupivacaine plus 3 μg dexmedetomidine (diluted in 0.5ml of normal saline) intrathecal. Group III: received 3 mL of 0.5% hyperbaric bupivacaine plus 5 μg dexmedetomidine (diluted in 0.5ml of normal saline) intrathecal. Group IV: received 3 mL of 0.5% hyperbaric bupivacaine plus 25 μg fentanyl (0.5ml) intrathecal. intraoperative heart rate and mean arterial blood pressure showed no statistical significant differences between the study groups, patients in group II, III and IV had significantly longer sensory and motor block times than patients in group I. The time of first request of postoperative analgesia was statistically significantly shorter in group I compared to the other groups. Pain scores were higher in group I compared to the other groups. Postoperative blood glucose level was only statistically significantly higher in group II compared to the other groups. Both intrathecal dexmedetomidine and fentanyl are associated with prolongation of sensory and motor block, with stable hemodynamics, minimal effect on blood glucose level, and better postoperative analgesia, compared to intrathecal bupivacaine alone. [Med-Science 2015; 4(3.000): 2450-64]

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Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
www.medicinescience.org | Med-Science
2450
Comparative Study of two Doses of Intrathecal Dexmedetomidine Versus
Fentanyl as Adjuvant to Hyperbaric Bupivacaine Spinal Anesthesia
Mahmoud M Amer, Doaa A Rashwan, Maha A Shaker
Anesthesia and SICU Department, Faculty of Medicine, Beni Suef University, Egypt
Abstract
The aim of this study was to evaluate the effect of addition two different doses of
dexmedetomidine or fentanyl to intrathecal hyperbaric bupivacaine on spinal block
characteristics, intraoperative hemodynamics, the blood glucose level and postoperative pain.
100 patients ASA I and II, ages 20 -60 years old undergoing elective surgeries below the
umbilicus under spinal anesthesia were divided into four groups (n=25 each): Patients were
randomly allocated into four equal groups (n= 25, each): Group I: received 3 mL of 0.5%
hyperbaric bupivacaine +0.5ml normal saline. Group II: received 3 mL of 0.5% hyperbaric
bupivacaine plus 3 μg dexmedetomidine (diluted in 0.5ml of normal saline) intrathecal.
Group III: received 3 mL of 0.5% hyperbaric bupivacaine plus 5 μg dexmedetomidine (diluted
in 0.5ml of normal saline) intrathecal. Group IV: received 3 mL of 0.5% hyperbaric
bupivacaine plus 25 μg fentanyl (0.5ml) intrathecal. intraoperative heart rate and mean
arterial blood pressure showed no statistical significant differences between the study
groups, patients in group II, III and IV had significantly longer sensory and motor block times
than patients in group I. The time of first request of postoperative analgesia was statistically
significantly shorter in group I compared to the other groups. Pain scores were higher in
group I compared to the other groups. Postoperative blood glucose level was only statistically
significantly higher in group II compared to the other groups. Both intrathecal
dexmedetomidine and fentanyl are associated with prolongation of sensory and motor block,
with stable hemodynamics, minimal effect on blood glucose level, and better postoperative
analgesia, compared to intrathecal bupivacaine alone.
Key Words: Spinal anesthesia, bupivacaine, dexmedetomidine, fentanyl
Rec.Date: Dec 22, 2014 Accept Date: Jan 26, 2015)
Corresponding Author: Doaa A Rashwan, Anesthesia and SICU Department, Faculty of
Medicine, Beni Suef University, Egypt
E-mail: doaa_rashwan2007@yahoo.com

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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Introduction
Spinal anesthesia is the most commonly used neuraxial anesthetic technique for operations of
the lower limbs and lower abdomen [1,2]. Spinal anesthesia has some the advantages (e.g.
Preservation of spontaneous respiration, relaxation in the bowel and abdominal wall thus
facilitating surgery) [3], these advantages are limited by the short duration of action of local
anesthetics when used alone and by side effects as hypotension and bradycardia [2,4], many
adjuvants can been used to prolong the anesthetic and analgesic effect of local anesthetics [5].
The quality of spinal anesthesia can be enhanced by the addition of fentanyl when added to
hyperbaric bupivacaine [6].
Dexmedetomidine, a highly selective alpha2 adrenoreceptor agonist, has been approved by
Food and Drug Administration (FDA) in1999 for analgesia and sedation in the intubated
patients at the intensive care [7], when used intrathecally in animals it provided potent
antinociceptive effect [8,9]. It prolongs the sensory block by acting on presynaptic C fibers
and decrease the neurotransmitter release, it prolongs the motor block by binding to motor
neurons in the spinal cord [10,11].
Alpha-2 adrenoceptor agonists can cause hyperglycemia in humans through postsynaptice
alpha 2-adrenoceptor stimulation of pancreatic B cells, thus inhibiting insulin release [12].
The aim of this study was to evaluate the effect of adding two different doses of
dexmedetomidine versus fentanyl to intrathecal hyperbaric bupivacaine on the onset and
duration of motor and sensory block, intraoperative hemodynamics, the blood glucose level,
postoperative pain and complications.
Patients and Methods
After approval of the review board of department of anesthesia and SICU at Beni Suef
University Hospital and the local ethics and research committee, a written informed consents
were obtained from each patient before the operation.
This study enrolled 100 patients of both sex undergoing elective surgical procedures below
the umbilicus under spinal anesthesia (e.g. lower abdominal and lower limb surgeries) at Beni
Suef University Hospital, Egypt, from March 2012 to February 2014.

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
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Exclusion Criteria
1. ASA>II Patients
2. Diabetes mellitus, neuromuscular, hepatic, ,adrenal gland abnormality or major renal
disease
3. Known allergy. to amide local anesthetics, dexmedetomidine or fentanyl.
4. Patients using steroids, alpha 2 receptor antagonists, calcium channel blocker
5. Contraindication to spinal anesthesia (e.g. patient refusal, coagulation disorder, infection at
the puncture site and tight valvular heart lesion).
Preparation of the Patients
The study protocol and the visual analogue scale (VAS) for pain were explained to the
patients preoperatively.
In the operating room, a wide bore intravenous cannula was inserted, preload with 10 ml/kg
Ringer solution.
Electrocardiogram, pulse oximetry, and non-invasive arterial blood pressure cuff were
applied, blood glucose level measured by glucometer.
Patients were randomly allocated by closed envelope technique for randomization into four
equal groups (no=25, each), to maintain the blind nature of the study, the studied drug were
given by a well-trained senior anesthesiologist according to the instructions written in a sealed
envelope as follows:
Group I: received 3 mL of 0.5% hyperbaric bupivacaine.
Group II: received 3 mL of 0.5% hyperbaric bupivacaine plus 3 μg dexmedetomidine
(diluted in 0.5ml of normal saline) intrathecal.
Dexmedetomidine (Precedex 100 μg/ml; Hospira, Inc., Lake Forest, IL 60045 USA).

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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Group III: received 3 mL of 0.5% hyperbaric bupivacaine plus 5 μg dexmedetomidine
(diluted in 0.5ml of normal saline) intrathecal.
Group IV: received 3 mL of 0.5% hyperbaric bupivacaine plus 25 μg fentanyl (0.5ml)
intrathecal. Fentanyl (Fentanyl-Janssen 50 μg/ml; Janssen-Cilag).
For all groups, the used hyperbaric bupivacaine is (Sunnybupivacaine 20mg/4ml; Sunny
Pharmaceutical). Normal saline 0.5ml was added to the hyperbaric bupivacaine in group I to
make the volume 3.5ml
Spinal anesthesia was performed under strict aseptic technique in the sitting position, 2ml
lidocaine 2% for local infiltration of the skin at L3-L4 or L4-L5 space, then insertion of 22-G
Quincke type spinal needle by midline approach, when free flow of CSF was obtained the
study drug was injected spinal needle was withdrawn and the patients were put in the supine
position immediately, supplemented with oxygen 3 L/min by face mask.
At the end of surgery, all patients were transferred to PACU where they were monitored and
discharged from the PACU to the ward, after achieved complete reversal of sensory and
motor block.
The following parameters were evaluated and recorded
1-Demographic data: age, sex, weight, height
2-Hemodynamic parameters: heart rate, mean arterial blood pressure were recorded before
anesthesia. After performing the spinal block the mean arterial blood pressure and heart rate
were recorded every 5 minutes for the first 20 minutes and then every 15 minutes
intraoperative and before the patient discharge from the PACU to the ward. Hypotension was
defined as a decrease of systolic blood pressure by more than 30% from baseline or a fall
below 90 mmHg and if maintained, was treated with IV fluid, incremental doses of
intravenous ephedrine 5 mg as required. Bradycardia defined as a heart rate<50 beats/min,
was treated with 0.5 mg of intravenous atropine.
3-Number of patients who required atropine or ephedrine intraoperatively
4- The highest level of sensory blockade assessed by pin prick.

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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5-Time to reach the maximum sensory level in minutes
6- Time to sensory regression to S1 in minutes
7- Onset time to modified Bromage3 in minutes
The motor block was assessed and recorded using Modified Bromage Scale (13) : Bromage 0=
the patient is able to move the hip, knee and ankle; Bromage 1= the patient is unable to move
the hip, but is able to move the knee and ankle; Bromage 2= the patient is unable to move the
hip and knee, but is able to move the ankle; Bromage3= the patient is unable to move the hip,
knee and ankle every 2 minutes for the first l0 minutes and there after every 5 minutes until
Brormage 3 is reached
8- The motor block duration: the time for regression to Bromage 0 in minutes
9-The level of sedation using Ramsay sedation scale: scale l=patient anxious, agitated, or
restless; scale 2=patient cooperative, oriented, and tranquil alert; scale 3=Patient drowsy
butresponsive to commands; scale 4= Asleep, but with brisk response to light glabellar tap or
tactile stimulation; scale 5=asleep with a sluggish response o light glabellar tap or tactile
stimulation and scale 6= asleep and no response [14].
10- Blood glucose level: preoperative, one hour after the onset of the operation and
immediately postoperative by glucometer.
11- The severity of postoperative pain for 24 hours at l, 6, 12, l8, and 24 h postoperatively
using VAS
12- Time to first request of postoperative analgesia in minutes: the time from the end of
surgery to the time of first request for analgesia
13-Number of patients required postoperative analgesia (Tramadol hydrochloride 1mg/kg IV)
in 24 hours
14-Postoperative complications: sedation, hyperglycemia, hypotention, pruritus.

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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Statistical Analysis
Data are presented as mean ±SD, median and range, mode, number and percentage as
appropriate. Parametric data were analyzed using One way ANOVA, Kruskal-Wallis test was
used for analysis of non-parametric data. P value <0.05 value was considered statistically
significant. Statistical Package for Social Science (SPSS) software version 17 was used.
Results
All patients completed the study, there were no statistical significant differences between the
studied groups as regards to the patient characteristics and operative data, (Table1).
Table 1. Patient characteristics and operative data in the studied groups. Data presented as
mean ±SD, numbers.
Variables
Group I
(n=25)
Group II
(n=25)
Group III
(n=25)
Group IV
(n=25)
Age (Years)
44.7±11.9
41.8±14.5
44.3±11.5
42.0±13.1
Height (cm)
167.2±3.3
168.6±4.6
167.4±4.3
169.9±5.7
Wight (kg)
84.2±10.3
80.3±10.2
79.04±10.02
83.56±7.00
Gender (M/F)
15/10
17/8
14/11
17/13
ASA (I/II)
21/4
19/6
16/9
20/5
Duration of surgery (min)
80.6±20.1
78.4±22.9
95.4±30.6
86.3±25.6
Group I: hyperbaric bupivacaine
Group II: 0.5% hyperbaric bupivacaine +3 ug dexmedetomidine
Group III: 0.5% hyperbaric bupivacaine + 5 ug dexmedetomidine
Group IV: 0.5% hyperbaric bupivacaine +25 ug fentanyl
No statistical significant differences between the studied groups, P values >0.05

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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Intraopeartive heart rate showed no statistical significant differences between the study
groups, (Table2).
Table 2. Intraopeartive heart rate( Bpm). Data presented as mean ±SD.
Time
Group I
(n=25)
Group II
(n=25)
Group III
(n=25)
Group IV
(n=25)
Preanesthesia
83.3±13.0
80.0±10.8
80.2±7.0
82.2±8.6
After anesthesia
5 min
86.3±12.9
83.1±12.8
79.0±8.4
81.6±13.0
10 min
82.8±14.0
84.8±9.9
78.7±10.8
78.2±11.1
15 min
77.0±10.8
81.4±9.8
76.1±13.5
76.1±9.7
20min
77.9±8.7
80.9±8.9
76.0±14.6
78.1±10.9
35 min
76.9±10.7
79.4±8.6
75.4±14.7
77.5±9.5
50 min
74.0±8.1
77.2±9.2
74.8±15.2
76.6±7.3
65 min
79.2±8.1
76.9±8.0
75.4±15.1
77.0±7.1
80min
77.3±9.2
79.2±9.0
76.7±16.2
79.4±6.9
95 min
76.7±1.1
79.3±9.2
71.9±7.8
78.0±7.3
Before discharge
from PACU
78.1±7.9
76.0±7.0
75.5±14.1
77.8±7.1
Group I: hyperbaric bupivacaine
Group II: 0.5% hyperbaric bupivacaine +3 ug dexmedetomidine
Group III: 0.5% hyperbaric bupivacaine + 5 ug dexmedetomidine
Group IV: 0.5% hyperbaric bupivacaine +25 ug fentanyl
No statistical significant differences between the studied groups, P values >0.05

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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As regards to intraopeartive mean arterial blood pressure no statistical significant differences
between the study groups except at 95 minutes, (Table3).
Table 3. Intraopeartive mean arterial blood pressure (mmHg).Data presented as mean ±SD.
Time
Group I
(n=25)
Group II
(n=25)
Group III
(n=25)
Group IV
(n=25)
Preanesthesia
89.5±9.7
91.7±11.2
88.5±11.6
93.3±11.6
After anesthesia
5 min
87.5±10.9
89.1±8.3
84.4±10.6
90.5±11.7
10 min
82.8±17.7
89.9±15.4
82.7±10.3
84.4±9.7
15 min
79.6±16.3
85.2±15.3
82.2±10.1
79.8±9.0
20min
78.0±11.0
85.0±9.9
80.1±9.0
80.8±9.6
35 min
79.8±10.5
81.1±9.1
78.8±8.7
79.3±7.3
50 min
80.8±7.4
82.2±9.9
78.6±8.8
76.6±6.8
65 min
80.3±6.8
82.2±11.6
78.7±8.2
76.8±7.2
80min
82.3±6.4
76.9±10.4
77.2±8.7
78.8±5.0
95 min
80.7±6.7*
75.7±12.6
75.7±7.5
77.4±9.4
Before discharge
from PACU
78.1±7.9
82.9±7.8
77.3±9.9
79.1±8.4
Group I: hyperbaric bupivacaine
Group II: 0.5% hyperbaric bupivacaine +3 ug dexmedetomidine
Group III: 0.5% hyperbaric bupivacaine + 5 ug dexmedetomidine
Group IV: 0.5% hyperbaric bupivacaine +25 ug fentanyl
*P value <0.05 is statistically significant

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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Regarding the spinal block characteristics, no statistical significant differences between the
study groups in the highest sensory level, time to reach the maximum sensory level, but time
to sensory regression to S1was statistically significant lower in group I compared to the other
groups, onset time to modified Bromage 3 was statistically significantly lower in group IV
compared to the other groups, regression to modified Bromage 0 was statistically significant
lower in group I compared to the other groups (Table 4).
Table 4. Spinal block characteristics (Highest sensory level, onset and regression time of
sensory and motor blocks in minutes), data were expressed as mean ±SD, median and range
Variable
Group I
(n=25)
Group II
(n=25)
GroupIII
(n=25)
GroupIV
(n=25)
Highest sensory
level
4 (3-6)
5 (4-6)
4 (4-6)
4 (4-6)
Time to reach the
maximum sensory
level ( min)
13.6±6.2
10.6±4.6
10.8±4.0
10.5±3.7
Time to sensory
regression to S1 (
min).
263.8±42.7*
329.4±25.8
392.0±43.1
324.8±73.0
Onset time to
modified Bromage
3( min)
7.3±5.5
6.9±5.4
6.7±1.9
4.2±1.9*
Regression to
modified Bromage
0( min)
205.7±49.0*
257.4±35.4
266.6±49.9
227.8±58.2
Group I: hyperbaric bupivacaine
Group II: 0.5% hyperbaric bupivacaine +3 ug dexmedetomidine
Group III: 0.5% hyperbaric bupivacaine + 5 ug dexmedetomidine
Group IV: 0.5% hyperbaric bupivacaine +25 ug fentanyl
*P values <0.05 is statistically significant.

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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Blood glucose level was only statistically significantly higher in group II compared the
other groups (Table5).
Table 5. Blood glucose level mg/dl data expressed as mean ±SD
Variable
Group I
(n=25)
Group II
(n=25)
Group III
(n=25)
Group IV
(n=25)
preoperative
94.7±18.7
92.4±18.1
83.7±10.2
88.6±11.3
1 hour
89.8±18.8
97.4±25.4
86.4±9.6
87.3±11.9
postoperative
88.4±15.3
99.0±22.3*
86.6±8.1
90.6±10.4
Group I: hyperbaric bupivacaine
Group II: 0.5% hyperbaric bupivacaine +3 ug
dexmedetomidine
Group III: 0.5% hyperbaric bupivacaine + 5 ugdexmedetomidine
Group IV: 0.5% hyperbaric bupivacaine +25 ug fentanyl
*P values <0.05 statistically significant.

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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No statistical significant differences between the study groups in the number of patient
required atropine, ephedrine, patients required tramadol hydrochloride 50mg IV in 24 hours,
complications, but the time of first request of postoperative analgesia was statistically
significantly shorter in group I compared to the other groups (Table 6).
Table 6. Number of patients required atropine or ephedrine, TFA additional analgesia,
complications, Data presented as mean ±SD, number (%)
Variable
Group I
(n=25)
Group II
(n=25)
Group III
(n=25)
Group IV
(n=25)
patients required
atropine No.(%)
1(4)
2(8)
3(12)
2(8)
patients required
ephedrine No(%)
3(12)
1(4)
2(8)
1(4)
TFA (min)
184.4±31.5*
227.5±25.2
278.8±53.6
218.0±61.3
Patients required
Tramadol
hydrochloride
50mg IV in 24
hours
19(76)
18(72)
16(61)
16(61)
Hyperglycemia
0(0)
0(0)
0(0)
0(0)
Hypotension
4(16)
3(12)
3(12)
1(4)
Sedation
0(0)
0 (0)
0(0)
0(0)
Pruritus
0(0)
0(0)
0(0)
0(0)
Group I: hyperbaric bupivacaine
Group II: 0.5% hyperbaric bupivacaine +3 ug dexmedetomidine
Group III: 0.5% hyperbaric bupivacaine + 5 ug dexmedetomidine
Group IV: 0.5% hyperbaric bupivacaine +25 ug fentanyl
TFA =Time to first request of postoperative analgesia (min)
*P values <0.05 statistically significant.

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
Original Research doi: 10.5455/medscience.2015.04.8240
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The visual analogue scale was statistically significantly higher in group I compared to the
other groups at 6,12 hours. Pain scores were statistically significantly lower with
dexmedetomidine 3μg and 5μg than group I and group VI at 24 hours (Table7).
Table 7. Postoperative Visual Analogue Scale, Data presented as mode
VAS
Group I
(n=25)
Group II
(n=25)
Group III
(n=25)
Group IV
(n=25)
1h
0
0
0
0
6h
6*
4
4
4
12h
5*
3
3
4
18h
5
4
3
4
24 h
4
2*
2*
3
Group I: hyperbaric bupivacaine
Group II: 0.5% hyperbaric bupivacaine +3 ugdexmedetomidine
Group III: 0.5% hyperbaric bupivacaine + 5 ugdexmedetomidine
Group IV: 0.5% hyperbaric bupivacaine +25 ug fentanyl
*P values <0.05 is statistically significant.
Discussion
The results of the present study showed that addition of intrathecal dexmedetomidine 3 μg
and 5 μg or 25 μg fentanyl to hyperbaric bupivacaine was associated with prolongation of
sensory and motor block, with stable hemodynamics and minimal effect on blood glucose
level, prolongation of time to first request of postoperative analgesia, reducing the
postoperative pain score compared to bupivacaine alone, no postoperative complications or
heavy sedation reported.
Kanazi GE and his coworkers [7] concluded that 3ug dexmedetomidine when added to
intrathecal bupivacaine resulted in rapid onset of motor block, prolongation in the duration of
motor and sensory block, hemodynamic stability and no sedation. Similarly It was shown that
the addition of dexmedetomidine3 µg to intrathecal 0.5% hyperbaric bupivacaine 6 mg in
patients undergoing transurethral prostatectomy produced fast onset and a prolonged duration
of sensory block and postoperative analgesia [15].

Medicine Science 2015;4(3):2450-64 Intrathecal Dexmedetomidine to Spinal Anesthesia
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In this study the addition of dexmedetomidine 5 ug to intrathecal heavy bupivacaine was
associated with prolongation of the time to postoperative analgesic requirements and
reduction in the VAS, less number of patients needed postoperative analgesia. Similar to our
results, a study by Vidhi Mahendru et al [1] showed that dexmedetomidine 5 ug with 12.5 mg
bupivacaine leads to prolongation of motor and sensory block, preserved hemodynamics and
decreased postoperative analgesic consumed compared to clonidine 30 ug, fentanyl 25 ug, or
12.5 mg hyperbaric bupivacaine alone in patients undergoing lower limb surgery, also 5 μg
dexmedetomidine as adjuvant to heavy bupivacaine 3.5 ml 0.5% provided earlier sensory and
motor blockade, increase in time to first analgesic request, less postoperative analgesic
requirements, with no complications in patients undergoing lower abdominal surgery under
spinal anesthesia [4,16] concluded that intrathecal dexmedetomidine 5 ug prolonged the
duration of sensory and motor block of bupivacaine in adult patients undergoing surgeries
below the level of umbilicus.
A meta-analysis by Xiao-Yin Niu et al [17] showed that dexmedetomidine prolonged the
duration of spinal anesthesia and enhance postoperative analgesia without increasing the
incidence of side effects. In this study the addition of dexmedetomidine 3 μg or 5 μg to
hyperbaric bupivacaine had minimal effect on the blood glucose level, dexmedetomidine can
increase blood glucose level during video gynecologic surgeries [18] and may cause
hypoinsulinemia when used as sedative in icu [19] due to its effect on postsynaptic α2
adrenoreceptors on β cells of the pancreas which results in decease insulin secretion [20].
Conclusion
The addition of intrathecal dexmedetomidine 3ug and 5ug or 25ug fentanyl to hyperbaric
bupivacaine was associated with prolongation of sensory and motor block, with stable
hemodynamics and minimal effect on blood glucose level, prolongation of time to first
request of postoperative analgesia, and reduction of the postoperative pain scores compared to
bupivacaine alone with no postoperative complications or heavy sedation reported in patients
undergoing elective surgical procedures below the umbilicus.

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