Our patient, a 52-year-old male (165 cm, 90 kg), was a known case of chronic lymphocytic leukemia (CLL, Rai Stage II). He had received two cycles of bendamustine and rituximab-based chemotherapy in two consecutive months. He developed herpes zoster infection in the following month and was started on oral acyclovir after consultation with a dermatologist. One week later, he visited our pain clinic and complained of severe pain on the right side of his lower back []. The pain was burning in nature and was associated with allodynia and restricted mobility. A diagnosis of PNH was made, and he was started on gabapentin in view of neuropathic nature of pain. The dermatomal distribution of the pain was from T11 to S1. The pain was affecting the quality of life of the patient and the pharmacological therapy was inadequate.\nWe decided to perform a right-sided ESPB in prone position for acute pain relief of the patient. A high-frequency linear ultrasound probe was placed in longitudinal orientation, about 3 cm lateral to the spinous process of the third lumbar vertebra. The interfacial plane below the erector spinae muscle was identified, and 0.25% bupivacaine and triamcinolone 40 mg (total volume 30 ml) were injected []. Patient's NRS score was decreased from 8/10 to 3/10 30 min after the block procedure. Later on, the ESPB was performed two times for 2 weeks and provided effective analgesia for the PHN. The patient reported a decline in pain score and analgesics consumption in follow-up clinics.
Case 4: A 65 years old male (weight 76 kg, ASA status III) was scheduled for left THA. He was diagnosed with AS for 10 years, and developed necrosis of both femoral heads, and could not walk because of pain in the left hip joint. He had a history of hypertension for 10 years, and diabetes mellitus for 7 years, and smoking history for 50 years with nearly 50 cigarettes per day. A chest X-ray revealed enhanced texture of bilateral lungs and right pleural effusion. X-ray of his pelvic revealed bilateral femoral head necrosis, narrowed joint space, osteoproliferation and bone defect under articular surface of bilateral sacra-iliac joints and hip joints, and bamboo-like changes of lower lumbar spine.