MINISTRY OF EDUCATION AND TRAINING

MINISTRY OF DEFENCE

108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES

-------------------------------------------------

TRAN THI CAM NHUNG

RESEARCH ON EFFICACY OF INTRAOPERATIVE
ANESTHESIA AND POSTOPERATIVE ANALGESIA BY
MIXTURE OF BUPIVACAINE WITH DEXMEDETOMIDINE
IN BRACHIAL PLEXUS BLOCK
FOR UPPER EXTREMITY BONE SURGERY

Speciality: Anesthesiology
Code: 62720122

ABSTRACT OF MEDICAL DISSERTATION

Hanoi - 2020


THE THESIS HAS DONE IN: 108 INSTITUTE OF CLINICAL
MEDICAL AND PHARMACEUTICAL SCIENCES

Supervisors:
1. Prof. Dr. Nguyen Van Chung
2. Dr.Tong Xuan Hung


1.1. Upper extremity fracture
Causes of the upper extremity fractures are popular due to
domestic accidents, machinery, playground injury or road traffic
accidents. In particular, the author Rubin and his colleagues reported
103465 cases of traffic accidents which had 17263 situations of
upper extremity fractures, the ratio of open fractures accounted for
16.7%, about 18.1% at adults and 13.2.% at children. In the
Netherlands, the frequency of upper extremity fractures had
accounted about 824/100 000 people for 9 years from 2004 to 2012
and tended to grow up following next time, more regularly in a group
of 16-35 years old, more man than female.
1.2 Anesthetic techniques for upper extremity bone surgery
There are many anesthetic techniques for upper extremity
surgeries, such as intravenous regional anesthesia (Bier block),
brachial plexus block, general anesthesia.
Advantages of brachial plexus block are not only simple
technique, but also reducing or losing provisional sensation and
movement of upper extremity. Patients still awaken, recovery early,
lessen caring of health care staff and family’patient. Especially, it is
lower cost than general anesthesia.
1.3 Brachial plexus block
The brachial plexus is formed from five roots, the anterior rami
of the spinal nerves from C5 - T1, they connect together to form 3
trunks, after the roots pass between the scalene muscles they meet
the subclavicular artery and divide into divisions.


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In the three trunks, the superior trunk arises from the union of

branches and rapid onset time of sensory block due to small nerves
and minimum local anesthetic.
Supraclavicular brachial plexus block may have some
complications such as about 0.04 - 1% pneumothorax, subclavicular
artery puncture, Claude Bernard Horner syndrome, phrenic nerve
block rarely.
1.4 Using drug in brachial plexus block of our study
Bupivacaine which is local anesthetic, is exerted to block
recoverable conduction of nerve impulse, through mechanism to
inhibit depolarization of neural membrane by preventing of Na+ to
pass this membrane. Bupivacaine inhibits stronger sensory fibers
than motor fibers, because motor fibers have myelin sheath and


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diameter of these fibers larger than sensory fibers. The duration time
has about 3 - 4 hours.
Dexmedetomidine is a highly selective a2 adrenoreceptor
agonist which has eight times higher effective than clonidine’s. The
ratio of a2:a1 adrenoreceptor of dexmedetomidine is approximately
1620:1, to have anxiolytic, sedative and analgesic effect. Four
analgesic mechanism of dexmedetomidine in brachial plexus block
are demonstrated by Brummett C (2008) through stimulation of
central and peripheral α2 adrenoreceptor, causing central analgesic
effect, vasoconstriction around injection site, anti-inflammatory and
direct analgesic effect on peripheral nerves. Dexmedetomidine
connects with anesthetic drug helps to prolong the duration of
anesthesia and analgesia on the peripheral nerve through the indirect
mechanism due to vasoconstriction at the injection site, however, the

Clinic Hospital.
2.3 RESEACH METHODOLOGY
2.3.1 Study Design: It was a controlled, randomized, interventional
prospective clinical study.
2.3.2 Sample size and division of patient group
Using the test formula for comparison of two average numbers


6

2C
( ES ) 2
α is the probability of type 1 error, α = 5%, β is the probability of
n

type 2 error, β = 20%, to look at table 3 and get a constant C = 7.85.
In a study of Agarwal S. (2014), μ1 which is postoperative analgesic
time of bupivacaine with dexmedetomidine group, is 776 minutes
and σ1 which is standard deviation of postoperative analgesic time, is
130.8 minutes. μ2 is the expected postoperative analgesic time in our
study when we will use a connection of bupivacaine with
dexmedetomidine, increasing about 10% postoperative analgesic
time of Agarwal’s study, so this time is 850 minutes.
Filling this parameters into this formula, and calculating n =
49.1. Therefore, we selected 54 patients for each group.
2.3.3. Devices, facilities and drugs of research
- Ultrasound machine with linear probe, frequency 6 - 12MHz of
Ezono AG company.
- Stimuplex A needle for brachial plexus block of B. Braun company.
- VAS (Visual Analog Scale) ruler .

mixture of bupivacaine 0.25% and 100mcg dexmedetomidine.
2.3.4.3 Practice by supraclavicular brachial plexus block via
ultrasound guidance
The patient's position was lying on an operative table, injuried
hand was closed to body, his head was faced to the opposite side of
brachial plexus block. An anesthesiologist used an ultrasound probe
to determine location of the brachial plexus where is above the
clavical bone. Holding the transducer plane in a direction that was
parallel to body's axis, so that ultrasound beam crossed the brachial
plexus and subclavicular artery located on the first rib. Once the
brachial plexus was adequately identification of the neural structures
as round or oval multiple hypoechoic structures, next to the


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subclavicular artery. We injected needle slowly and observed its
direction of on the screen, keeped it below the brachial plexus, next
to the subclavicular artery. An assistant installed the syringe
containing mixture of local anesthetic with connected line of needle,
drawed this syringe test if there was no blood, started to inject 3-5ml
then checked again per each time after injection. When anesthetic
mixture was injected 15ml, needle was stopped and moved it
upwards to brachial plexus, continued to inject 15ml of this
anesthetic, the anesthetic mixture slowly spread around brachial
plexus on screen of ultrasound.
To monitor the patient in 30 minutes after brachial plexus
block: if the patient had completed pain sensory blockage, surgery
would be performed. If the patient was still moderate pain, we would
give them fentanyl 1-2 mcg/kg, and/or midazolam 0.02 - 0.04 mg/kg

diastolic blood pressure (DBP), average blood pressure (ABP), heart
rate.
- Sedative effect: onset and duration time, sedative level.
- Monitor breathing rate and SpO2.
- Adverse effects due to local anesthetic
-Adverse effects due to anesthetic technique
2.3.6 Methods of evaluation
- Evaluation of pain sensory blockage by pin-prick method: after
anesthesia, we used a needle to prick test sensory pain on
dermatomes where be controlled by roots from C5 to T2, and radial
nerve, median nerve, ulnar nerve, compared with the opposite side.
In particular, C5 dominates sensory pain of arm’s outside, C6
dominates sensory pain of forearm’s outside, C7 dominates sensory
pain of the hand, C8 dominates sensory pain of the forearm’s inside,
T1 dominates sensory pain of the arm’s inside and T2 dominates
sensory pain of underarm. The radial nerve dominates sensory pain


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on the back of the thumb and II finger, the median nerve dominates
sensory pain on the palm of III and IV finger, the ulnar nerve
controls sensory pain on the palm of V finger.
- The level of pain sensory blockage for upper extremity during
surgery was assessed following the author Agarwal’s research,
divided to 3 grades, grade 0: normal sensation; grade 1: a little loss
of sensation of pin-prick (analgesia); grade 2: complete loss of pain
sensation (anesthesia).
- The level of motor blockage for upper extremity was assessed
by Bromage scale, divided into 3 grades, grade 0: normal motor

until patient feel loss sensory block with grade 1 according to the
classification of Agarwal, was dominated by roots from C5 to T2, and
radial nerve, median nerve, ulnar nerve, unit in minutes.
- Duration time of pain sensory blockage of whole upper
extremity was defined as the time from patient felt loss sensory block
with grade 1 until completely sensory recovery with grade 0
according to the classification of Agarwal, unit in minutes.
- Onset time of motor blockage was defined as the time from the
end of local anesthetic administration until patient decreased motor
strength with ability to move the fingers only, grade 1 according to
the classification of Bromage, unit in minutes.
- Duration time of motor blockage was defined as the time from
patient decreased motor strength with ability to move the fingers
only (grade 1) until completely motor recovery (grade 0), unit in
minutes.
- Postoperative analgesic time was defined as the time from the
end of the surgery to the time of pain appearance, unit in minutes.
- Hypotension: systolic blood pressure (SPB) was less than 90
mmHg in a case of an initial SPB  110 mmHg, or SPB droped of
more than 20% of the initial SPB = 90 - 109 mmHg.


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- Bradycardia: heart rate was slow when < 50 beats/minute in the
initial frequency with 60 - 100 beats/minute or heart rate droped of
more than 20% of the initial frequency = 50 - 59 beats/minute.
- Onset time of sedation was defined as the time from the end of
local anesthetic administration until patient had OAA/S = 4 score and
recorded the sedative level, unit in minutes.

Brachial plexus block, 30 ml
bupivacain 0.25% (75mg)

Brachial plexus block, 30 ml
bupivacain 0.25% +
dexmedetomidin 100 mcg

General characteristics of the patient and surgery
- Age
- ASA classification
- Gender
- Historical chronic disease
- Weight, height
- Surgical location
- BMI
- Time surgery

Comparing intraoperative anesthetic and postoperative analgesic efficacy
- Sensory blockage: level, onset and duration time
- Motor blockage: level, onset and duration time
- Intraoperative anesthetic efficiency
- Postoperative analgesic efficacy: analgesic time và VAS score

Evaluation on BP, heart rate, sedative effects and some adverse effects by
mixture of bupivacaine with dexmedetomidine
- Vital signs by monitor: BP, HR, ECG, SpO2 at before and after
brachial plexus block.
- Intraoperative sedation: level, onset and duration time
- Some adverse effects
- Record some adverse effects

Height (cm)

162.0 ± 7.1

163.4 ± 7.4

(min - max)

(145 - 176)

(148 - 176)

Weight (kg)

59.9 ± 12.0

59.1 ± 11.0

(min - max)

(37 - 105)

(40 - 90)

BMI (kg/m2)

22.7 ± 4.0

22.1 ± 3.4


demographic characteristics such as age, height, weight and BMI in
patient of both groups, p > 0.05.
3.2 Intraoperative anesthetic and postoperative analgesic efficacy
3.2.1 Intraoperative anesthetic efficacy


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Prevalence %
81.4
100
61.1
50

Group B
Group BD
20.4

p < 0.05

13

18.5

5.6

0
Excellent

Very good


(7 - 44)
486.6  206.2
(190 - 1035)
18.7  6.3
(8 - 33)
31.1  8.7
(12 - 46)
417.7  199.3
(140 - 910)

11.1  4.6
( 3 - 20)
824.5  244.8
(305 - 1630)
12.2  5.3
(4 - 28)
19.6  6.0
(10 - 34)
800.5  248.9
(180 - 1530)

p
< 0.05
< 0.05
> 0.05
< 0.05
< 0.05

Conclusion: Onset time of sensory and motor block with grade 2
in the BD group is statistically significant shorter than that of B

plexus block
3.3.2 Effect on heart rate
Heart rate
(beats/minute
B group
BD group

Time
Figure 3.7 Heart rate of two research groups
*: p < 0.05
Conclusion: Heart rate from T20 to T90 in BD group is
statistically significantly lower than that of B group, p < 0.05.


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3.3.3 Sedative effect
Prevalence %
87

100

Group B

80
60

Group BD
46.3
37

9.8  3.5

(min - max)

(4 - 18)

Duration

92.7  34.1

(min - max)

(50 - 200)

Conclusion: BD group has onset of sedative time which is 9.8 
3.5 minutes and duration time is 92.7  34.1 minutes.


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3.3.4 Adverse effects
Adverse effects
Horner syndrome

Group BD
Group B

14.8
5,6



Chapter 4
DISCUSSIONS
4.1. General characteristics of study patients
The average age in B and BD group is respectively 38.3  16.3
and 37  13.3 years old, the smallest is 15 years old and the highest
is 72 years old according to table 3.1. Consequently, the both groups
of our study have similar age characteristics, p > 0.05. The average
age in our study resembles to domestic author such as in Do Thi Hai’
research, age was 33 years old, the youngest was 13 years old and
the highest was 56 years old.
4.2 Comparing intraoperative anesthetic and postoperative
analgesic efficacy of bupivacaine and dexmedetomidine mixture
with bupivacaine alone
We find that the result of figure 3.1 when using bupivacaine
combined with dexmedetomidine, improves anesthetic effect very
well, excellent and very good level in BD group accounting for
94.4%, in good about 5.6% statistically significantly higher than B
group, in turn 81.5% and 18.5%, p < 0.05. The author Nguyen Van
Huan’ research (2008) used axillary brachial plexus block by nerve
stimulator, the rate of anesthetic effect was very good at 93.4% and
good at 6.6%. The successful rate of author Nguyen Thi Thanh’s
research (2013) was 91.4% by nerve stimulator. Tripathi A.’s
research (2016), anesthetic effect in BD group had 80% at very good
and 20% at good. Conclusion, anesthetic efficacy of our study is
similar to prevelance of domestic and foreign authors’s research.
In BD group of our study, onset time of sensory blockage on
whole upper extremity is 11.1  4.6 minutes, 3 minutes fastest and the
20 minutes longest, shorter than that of group B, is 17.1  8.3 minutes,


of Gandhi R. and et al. (2012), the onset of sensory and motor blockage in
combined dexemedetomidine group was faster than alone local anesthetic
group, duration of sensory and motor blockage were 732 minutes and 660
minutes, shoter than about 100 minutes of our BD group, is 825 and 800
minutes, explaining this difference may be due to two different assisted
technique in practiced anesthesia, we did ultrasound guidance while Gandhi
R. used anatomical technique to do brachial plexus block.
In addition, postoperative analgesic time was 776 minutes of added
dexmedetomidine group in Agawal’s research (2014), shorter than that of our
BD group with 970 minutes (table 3.16), although both studies used the same
100mcg dexmedetomidine, but we used ultrasound guidance to help this
drugs access brachial plexus better. Besides, research of Biwas S. and et al
(2014), recorded postoperative analgesic time of local anesthetic and 100mcg
dexmedetomidin was 997 minutes, it is seem similar to our study. Thus,
combination of dexmedetomidine to local anesthetic in brachial plexus block


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can prolong postoperative analgesic time has been shown by many studies,
even if only a single dose of dexmedetomidin is used for one injection.
4.3 Evaluating on blood pressure, heart rate, sedative effects and
some adverse effects of bupivacaine and dexmedetomidine
mixture by brachial plexus block for upper extremity bone
surgery
There are about 50% patients who feel anxious during perioperative
time, so sedation for patients is extremely necessary, helping patients feel
secure and cooperative. According to the chart 3.4, BD group in our study has
about 87% of OAA/S = 4 points, higher than B group’s, only 37%,
statistically significant difference, p < 0.05 (figure 3.8). Onset and duration of


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CONCLUSIONS
Our study of supraclavicular brachial plexus block under
ultrasound guidance for 108 patients who had divided two groups,
the BD group received 75mg bupivacaine and 100 mcg
dexmedetomidine comparison to the B group received 75mg
bupivacaine, some conclusions as follows:
1. The BD group has onset time of sensory and motor blockage
which is 11.1  4.6 minutes and 19.6  6.0 minutes faster than that of
B group, gets 17.1  8.3 minutes and 31.1  8.7 minutes, p < 0.05.
Moreover, the prevalence of achieved excellent and very good
anesthesia which is 94.4% and 5.6% at good anesthesia in BD group
statistically significantly more than group B has respectively had
81.5% and 18.5%, p < 0.05. In addition, postoperative analgesic time
is 970.5  309.5 minutes in BD group more than group B, is 552.7 
231.2 minutes, p < 0.05. BD group has had rested and motivational
VAS score statistically significantly lower than that of B group at 12,
16 and 24 hour after brachial plexus block, p < 0.05.
2. The BD group has had an average blood pressure from 45th
minute to 120th minute lower than B group’s, p < 0.05. In addition,
heart rate of BD group has shown lower than B group’s from 20th
minute to 120th minute after brachial plexus block, statistically
significant differences, p