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Background and Aims Caudal epidural blockade (CEB) is a technique also used in chronic pain management. Although fluoroscopy is the gold standard technique, ultrasound gained popularity due to its high success rates, accessibility and lower radiation exposure.

Methods 53-year-old man with low back pain radiating to his right leg for six months with paresthesias, difficulty in gait and decreased sleep quality. Lumbar MRI revealed disc protrusions at levels L4-L5, L5-S1 and electromyography showed signs of acute on chronic root distress of the right L5 nerve. One month of physiotherapy and oral analgesia showed no improvement and the patient was waiting for a neurosurgery consultation. We proposed a CEB which the patient consented to.

Results CEB was performed with the patient in prone and standard ASA monitoring. The sacral hiatus was identified using a linear probe in transverse and longitudinal planes. An ultrasound-guided longitudinal in-plane approach was performed using a 21G needle. After puncturing the sacrococcygeal ligament a solution of 2mL 2% lidocaine, 6mg betamethasone and 8mL saline was administered. Unidirectional flow was confirmed using color Doppler mode. No complications were reported. One month later, the patient returned reporting marked pain relief, normalized gait pattern, and reduced frequency of physiotherapy. He had the neurosurgery consultation, but surgery was delayed due to lack of clinical criteria. After four months the patient remained pain-free.

Conclusions -Ultrasound demonstrates high success rates in CEB. -Ultrasound allows for lower radiation exposure with more accessible equipment. -CEB is effective in treating refractory low back pain and can delay or avoid more invasive procedures.