Authors: Vadgama J et al.
Source: Cureus 17(11): e96504, DOI: 10.7759/cureus.96504
Summary
This case report describes the use of an anterior quadratus lumborum block (AQLB) as a rescue regional anesthetic technique for severe, refractory acute lower back pain in the emergency department. A 49-year-old man presented with debilitating bilateral flank and lumbar pain radiating to the groin and leg, initially suspected to be renal colic. Imaging and labs ruled out obstructive uropathy and infection, and pain remained severe despite multimodal systemic analgesia including opioids and NSAIDs. Examination revealed marked tenderness over the quadratus lumborum (QL) muscles with positive lateral flexion tests—findings consistent with QL syndrome, an under-recognized myofascial source of acute back pain.
Ultrasound-guided bilateral AQLB was performed using 30 mL of 0.18% ropivacaine per side with intravenous dexamethasone. Pain scores improved rapidly from 8/10 to 2/10 within 30 minutes, enabling full mobilisation and discharge on oral analgesics and physiotherapy instructions. He maintained low pain levels for 24 hours but re-presented three days later with recurrence, likely related to incomplete physiotherapy engagement and ongoing QL spasm.
This report highlights AQLB as a highly effective rescue intervention in the ED for patients with QL syndrome whose pain does not respond to maximal systemic therapy. The block appears to interrupt the QL pain–spasm cycle, supports rapid mobilisation, reduces opioid burden, and may prevent unnecessary admissions. Adjuncts such as dexamethasone may extend block duration, though evidence in nonoperative settings remains limited. Broader ED adoption of ultrasound-guided regional techniques like AQLB could substantially improve outcomes, reduce repeat visits, and optimize resource use.
What You Should Know
• QL syndrome is an underdiagnosed cause of acute low back and flank pain and may mimic renal colic.
• AQLB can provide rapid, dramatic pain reduction when systemic analgesia fails.
• Early pain relief allows mobilisation and facilitates physiotherapy—critical for breaking the pain-spasm cycle.
• Adjuncts such as dexamethasone may extend block duration, but more research is needed.
• Increasing the use of regional anesthesia in the ED can reduce opioid use, hospital admissions, and return visits.
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