Novel use of epidural catheter: Air injection for neuroprotection during radiofrequency ablation of spinal osteoid osteoma.

Osteoid osteoma (OO) is a benign bone tumor, with a male-female ratio of approximately 2:1 and mainly affecting long bones. Ten percent of the lesions occur in the spine, mostly within the posterior elements. Treatment options for OO include surgical excision and percutaneous imaging-guided radiofrequency ablation (RFA). Lesions within the spine have an inherent risk of thermal damage to the vital structure because of proximity to the neural elements. We report a novel use of the epidural catheter for air injection for the neuroprotection of nerves close to the OO of the spine. A 12-year-old and 30 kg male child with an OO of the L3 vertebra was taken up for RFA. His preoperative examinations were within normal limits. The OO was very close to the L3 nerve root. Under general anesthesia, lumbar epidural catheter was placed in the L3-L4 space under imaging guidance. Ten ml of aliquots of air was injected under imaging guidance to avoid injury to the neural structures due to RFA. The air created a gap between neural elements and the tumor and served as an insulating material thereby protecting the neural elements from damage due to the RFA. Postoperatively, the patient did not develop any neurological deficit.

The analgesic effect of intrathecal dexmedetomidine or clonidine, with bupivacaine, in trauma patients undergoing lower limb surgery: a randomised, double-blind study.

This randomised, double-blind study was designed to compare the duration of analgesia and adverse effects following intrathecal administration of dexmedetomidine or clonidine, both with bupivacaine, in trauma patients. Ninety adult trauma patients of American Society of Anesthesiologists physical status I-II, scheduled for lower limb surgery under subarachnoid block, were randomly allocated to one of three groups. All groups received hyperbaric bupivacaine 0.5% 3 ml, to which was added saline 0.5 ml (Group B): clonidine 50 µg (Group C) or dexmedetomidine 5 µg (Group D). The onset and duration of sensory and motor blockade, severity of postoperative pain, time to first rescue analgesia and total analgesic requirement for 24 hours were noted. There was no significant difference in the onset time of the block but the duration of sensory and motor blockade was prolonged in Groups C and D, compared with Group B. The time to analgesia was significantly prolonged in Group D (824±244 minutes) compared with Group C (678±178 minutes; P=0.01), the latter being longer than Group B (406±119 minutes; P=0.0001). Postoperative pain scores were lower in Groups C and D compared with group b. The requirement for rescue analgesia during the first 24 postoperative hours was significantly less in Groups C and D as compared to Group B (P=0.0001), but comparable between Groups C and D (P=0.203). In conclusion, dexmedetomidine 5 µg added to intrathecal bupivacaine 15 mg produces longer postoperative analgesia than clonidine 50 µg among trauma patients undergoing lower limb surgery.