During recent years, dexmedetomidine (DEX), a selectively
stimulating α- 2 adrenoceptor agonist, has emerged as an
efficacious local anesthetic (LA) adjuvant in regional and spinal
anesthesia. Originally clearanced for ICU sedation, it is now
widely used as a surgical anesthetic given its properties of
sedation, anxiolysis, and opioid-sparing effects with minimal
Trauma continues to be a major contributor to mortality and
1
morbidity, disability burden, economic costs . Apart from the
immediate traumatic physical suffering, there is often
prolonged, pain and psychological morbidity and something we
particularly see in orthopaedic trauma. Better pain control has
facilitated early mobility and may result in fewer long-term
2
sequelae , contributing to better overall outcomes. Good pain
control can facilitate recovery from orthopedic surgeries, and
this is particularly important for lower limb orthopedic
3
procedures .
INTRODUCTION
The present study aims to compare the effects of two different
doses of dexmedetomidine (3 µg, 5 µg) by adding it with 0.5%
hyperbaric bupivacaine in lower limb orthopedic surgeries.
Possible dosing strategies to limit these unwanted effects in an
effort to optimize patient comfort and surgical outcomes are
being additionally assessed during this study using parameters
such as sensory block duration, motor block properties and
requirements for postoperative analgesia.
Previous studies have shown that dexmedetomidine could
improve block quality and decrease the number of rescue
12,13
analgesia during orthopedic surgeries . Nonetheless, no
agreement exists regarding the optimal dosing regimen for
achieving maximum analgesic effectiveness with minimal
14
adverse events .
Spinal anesthesia is the method chosen most frequently for
lower limb surgery because of its high quality sensory block.
Nonetheless, the duration of 0.5% hyperbaric bupivacaine by
itself is relatively short and a prolonged surgery could be
8,9
converted to general anesthesia, . Dexmedetomidine inhibits
the release of neurotransmitter in presynaptic C-fibers and
postsynaptic dorsal horn neurons, thereby prolonging both
10
sensory and motor blockades at LA concentrations that do not
completely block. Two to three studies have assessed different
dexmedetomidine doses (2 > 10 µg), aiming for pain control
11
without significant adverse effects .
4,5
respiratory depression . When used as an intrathecal
adjuvant, dexmedetomidine along with local anaesthetics such
as 0.5% hyperbaric bupivicaine is proven to increase the
duration of both sensory and motor blockade hence being
6,7
beneficial in surgeries requiring longer analgesia .
03
Methodology: A randomized controlled trial done at LUMHS,
Jamshoro, from March 2023 to March 2024. 114 patients (ASA
µ2) planned for lower limb orthopedic surgery were randomly
allocated into two groups. Group A were given 12.5 mg of 0.5%
hyperbaric bupivacaine plus dexmedetomidine (3 µg)
intrathecally whereas group B received the same combination
with 5 µg dexmedetomidine. The primary outcomes of this
study were sensory and motor block assesment score,
hemodynamic responses, and any complication associated
during the perioperative period. The data was then statistically
analyzed with SPSS version 26 and the level of significance (P
<0.05).
ABSTRACT
Objective: To compare the outcome of two different doses of
dexmedetomidine (3 µg and 5 µg) given in combination with
0.5% hyperbaric bupivacaine via intrathecal route in patients
undergoing lower limb orthopedic surgeries at LUMHS
Jamshoro.
Conclusion: This study confirmed that supplementation of
dexmedetomidine, usually at 5 µg, can be a useful adjuvant to
hyperbaric bupivacaine for lower limb surgeries under spinal
anesthesia. It is longer acting and has a prolonged time to first
rescue with higher dose which makes it suitable for long
duration procedures. Results of our study suggest that further
investigations need to be carried out in order to detect a dose
where these two parameters are a more balanced concomitant
effect without causing hemodynamic instability.
Results: Group A had a mean age of 37.38 ± 22.57 years, and
group B, 41.40 ± 22.36 years. Group A had 72% males and 28%
females, while group B had 56% males and 44% females. No
intergroup differences were detected while comparing results
for TTHSB, TTBS4 and TDOS (p = 0.612, p = 0.230 and p =
0.602 respectively). However, significant differences were
observed for time to sensory block initiation (TTSI) (p = 0.003)
and time to first rescue analgesia (TTFRA) (p = 0.0001),
indicating variations in sensory block initiation and the time to
first rescue analgesia between the groups.
Keywords: Anaesthesia, Dexmedetomidine, Lower limb, Orthopaedic, Surgery
1 2 3 4 5
Waqar Hussain , Kelash Kumar , Aqsa Soomro , Arslan Baig , Pardeep Kumar
Corresponding Author
Senior Medical Officer, Liaquat University of Medical and Health
Sciences (LUMHS)
Email: [email protected]
2.
Assistant Professor, Department of Anaesthesia, Liaquat University
of Medical and Health Sciences (LUMHS)
3.
Senior Medical Officer, Isra University Hospital
4.
Resident, Isra University Hospital
5.
Resident, Liaquat University of Medical and Health Sciences
(LUMHS)
Submitted: August 30, 2024
Revised: September, 16, 2024
Accepted: September 16, 2024
Waqar Hussain
MS No: PJMDS/OA/019/2024
Dexmedetomidine as an Additive to Spinal
Anaesthesia in Orthopaedic Patients Undergoing
Lower Limb Surgeries: A Randomized Clinical Trial
Comparing Two Different Doses of Dexmedetomidine
Original Article
Pak J Med Dent Sci. 2024;1(1)
