Surgery with peripheral nerve block of the lower extremities under dexmedetomidine sedation for diabetic foot ulcers and chronic limb-threatening ischemia: a single-center questionnaire study and a retrospective observational study

Abstract

Abstract Background Patients who require surgical treatment for diabetic foot ulcer (DFU) or chronic limb-threatening ischemia (CLTI) are often in poor general condition and have complications. General anesthesia may be risky in surgery for such patients. Thus, we perform surgery using peripheral nerve block under dexmedetomidine sedation for patients with DFU and CLTI. Methods In this study, we investigated intraoperative stress and anxiety in a postoperative questionnaire and examined the safety of this procedure in 18 cases in which dexmedetomidine was used during peripheral nerve block. 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 nine 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.