Dexmedetomidine Added to Bupivacaine versus
Bupivacaine in Transincisional Ultrasound-Guided
Quadratus Lumborum Block in Open Renal
Surgeries: A Randomized Trial
Authors: Elbeialy Marwa A.K. 
Published: February 2021

Background: General anesthesia (GA) is the preferred anesthetic modality for open renal surgeries to
ensure a patent airway while the patient is in the lateral decubitus position. However, these surgeries
are usually accompanied by severe postoperative pain with increased requirements for multimodal pain
management strategies. Regional blocks provide better postoperative pain control with less systemic
opioid consumption.
Objectives: The aim of this study was to describe the ultrasound (US)-guided transincisional quadratus
lumborum block (TiQLB) as a new approach, and to compare the addition of dexmedetomidine to
bupivacaine versus bupivacaine alone for TiQLB in combination with GA regarding postoperative
analgesia and adverse effects in open renal surgery.
Study Design: A prospective, randomized, double-blind, controlled trial.
Setting: Ain Shams University Hospitals.
Methods: Eighty patients who were scheduled for an elective open renal surgery, aged 20 to 65 years,
of either gender, and American Society of Anesthesiologists physical status I to II were enrolled in the
study. They were randomly allocated into 2 equal groups: group dexmedetomidine-bupivacaine (DB) (n
= 40) in which patients received combined GA plus TiQLB with 30 mL bupivacaine 0.25% plus 1 μg/kg
dexmedetomidine, and group bupivacaine (B) (n = 40) in which patients received combined GA plus
TiQLB with 30 mL bupivacaine 0.25% only. The primary outcome was the total morphine consumption
among both groups, whereas the secondary outcomes were the Visual Analog Scale (VAS) scores and
the time to first analgesic requirement during the first 24 hours. Postoperative side effects, such as
sedation, nausea, vomiting, shivering, pruritus, bradycardia, hypotension, and respiratory depression,
were also recorded.
Results: Patients in the DB group experienced lower total morphine consumption and lower VAS
scores when compared with patients in the B group (P < 0.001). Time to first analgesic requirement
was prolonged in patients in the DB group (18.6 ± 2.4 hours) in comparison to patients in the B group
(7.3 ± 1.1 hours). Ten minutes after the block there was a significant reduction in mean blood pressure
and heart rate in the DB group than in the B group. Regarding postoperative adverse effects, sedation
scores were higher in the DB group than in the B group, postoperative nausea, vomiting, and shivering
were significantly higher in the B group than in the DB group. Bradycardia was significantly more
frequent among the DB group. Although nonsignificant, pruritus was more frequent in the B group
than in the DB group. No cases of respiratory depression were reported in both groups.
Limitations: The used technique US-guided TiQLB could be performed in open renal surgeries only.
Conclusions: The new approach US-guided TiQLB was effective and easy to be performed. Adding
dexmedetomidine to bupivacaine in TiQLB was associated with potent and prolonged postoperative
analgesia with fewer postoperative adverse effects.
Key words: Quadratus lumborum block, dexmedetomidine, open renal surgery, postoperative pain,
bupivacaine