The Efficacy and Safety of Continuous Popliteal Sciatic Nerve Block for the Relief of Pain Associated with Critical Limb Ischemia: A Retrospective Study

Abstract

Background: Patients with critical limb ischemia (CLI) often suffer from severe pain. A continuous peripheral nerve block has been shown to provide effective analgesia for patients having lower limb surgery. We have been administering continuous sciatic nerve block (CSNB) for patients with CLI whose pain could not be relieved by other analgesic tools. The aim of this retrospective study was to investigate the efficacy and safety of CSNB for patients with CLI. Method: We retrospectively investigated 99 patients who received CSNB for the relief of severe pain in the lower limb associated with CLI. Patient demographics, neurological history, complications, and subjective evaluation of the effectiveness of CSNB were investigated from their clinical records. The distal tips of 108 catheters were cultured. Result: One hundred and seventy-two catheters were placed in 99 patients. More than 90% of the patients enjoyed considerable relief of severe pain. The analgesic effect of CSNB was greater in patients with older age and hemodialysis. Thirty-one catheters had positive bacterial colonization. However, no severe infectious complication was found. There was no relationship between the co-existence of diabetes and positive bacterial colonization. We encountered a patient with ASO and diabetes who suffered from persistent motor weakness and hypesthesia even after 3 months of CSNB placement. Conclusions: CSNB provided good pain control for patients with severe pain caused by CLI. Although catheters were frequently found to be colonized, infection at the catheter site was self-limiting even in patients with diabetes.