Background: Trigger point injection is the current
standard in the management of abdominal myofascial
pain syndrome (AMPS). However, multiple
trigger point injections can cause significant
discomfort and there is a possibility of missing
trigger points resulting in a reduced efficacy of
trigger point treatment. Recently, abdominal wall
blocks have been reported in the management
of chronic abdominal wall pain. Transmuscular
quadratus lumborum block (TQLB) is a novel
abdominal wall block.
Objective: The report describes the role of the
ultrasound-guided TQLB with depot steroids in
the management of AMPS.
Study Design: Prospective case series.
Setting: Tertiary pain medicine clinic in a University
Hospital.
Methods: Adult patients with AMPS under the
care of a single physician were offered TQLBs
with a mixture of local anaesthetic and depot
methylprednisolone instead of multiple trigger
point injections as a part of an on-going prospective
longitudinal audit into the management of
AMPS. Patients completed brief pain inventory
questionnaire at baseline and at 12 weeks postprocedure.
Results: Thirty patients underwent TQLB. All patients
reported complete absence of pain within 15
minutes of the block and sensory testing revealed
extensive hypoaesthesia extending from thoracic
T6 to T12 anteriorly. Clinically significant benefit at
12 weeks was reported by 36% of patients, with
60% (18/30) of the patients preferring to receive
the novel intervention instead of multiple trigger
point injections. None of the patients reported
post-procedural flare up.
Limitations: Open label case series in a small
cohort.
Conclusion: The prospective series in a limited
cohort suggests that TQLB with depot steroids
could play a role in the management of AMPS.
Key words: Abdominal myofascial pain syndrome,
transmuscular quadratus lumborum block,
trigger point treatment, nonspecific abdominal
pain, viscerosomatic convergence
Ultrasound guided quadratus lumborum block for analgesia after cesarean delivery: case series
