Surgery With Peripheral Nerve Block Under Dexmedetomidine Sedation for Foot Ulcer.

Background: Patients who require surgical treatment for diabetic foot ulcer (DFU) or chronic limb-threatening ischemia (CLTI) are often in generally poor condition and have complications. General anesthesia may be risky in surgery for such patients. Thus, the authors perform surgery using peripheral nerve block under dexmedetomidine sedation for patients with DFU and CLTI. Methods: This study evaluated intraoperative stress, anxiety, and safety in 18 patients undergoing peripheral nerve block with dexmedetomidine. Sedation levels were assessed using the observer's assessment of alertness/sedation (OAA/S) score on a 5-point scale from 5 (awake) to 1 (deeply sedated). Postoperatively, a questionnaire was administered to assess intraoperative stress and memory. Intraoperative stress was assessed using a 6-point face scale (0 to 6: not at all to unbearably high), and intraoperative memory was rated on a 5-point numeric scale (1 to 5: no memory to everything). Results: The intraoperative OAA/S score was 3-5, indicating that appropriate sedation was obtained. The mean intraoperative stress score was 0.72 (range: 0-3), and the mean intraoperative memory score was 2.44 (range: 1-4). One patient had bradycardia and 9 had hypoxemia. All of these cases were improved by decreasing the dose of dexmedetomidine and encouraging deep breathing on call. Conclusions: These results suggest that this procedure is a useful method to reduce patient burden and alleviate stress and anxiety during surgery. However, dexmedetomidine may cause hypoxemia in patients with DFU or CLTI; thus, attention should be paid to hypoxemia and countermeasures should be taken against this adverse effect.