Sciatic Nerve Blocks With or Without Femoral Block Versus Spinal Anaesthesia in Patients Undergoing Diabetic Foot Surgery

Sciatic Nerve Blocks With or Without Femoral Block Versus Spinal Anaesthesia in Patients Undergoing Diabetic Foot Surgery

Haemodynamic and Pain Outcomes in Patients Undergoing Diabetic Foot Surgery Performed Under Sciatic Nerve Blocks With or Without Femoral Nerve Block Versus Spinal Anaesthesia

Background: Dysautonomia refers to the abnormal function of the autonomic nervous system including sympathetic and parasympathetic nervous system. Diabetes mellitus causes secondary dysautonomias (1). The Survey of Autonomic Symptoms (SAS) is a simple and validated tool to assess the presence and severity of autonomic symptoms (2). Diabetic patients also suffer from chronic neuropathic pain. After amputation surgeries, up to 78% of these patients may develop post surgical neuropathic pain (3). The self-report version of the Leeds Assessment of Neuropathic Symptoms and Signs pain scale (S-LANSS) is validated as a diagnostic tool to assess patients with neuropathic pain (4). This scale will be used to assess if there is any changes in the pain experienced after diabetic foot surgery. Currently, both spinal anaesthesia (SAB) and ultrasound guided femoral and sciatic peripheral nerve blocks (FSNB) are acceptable anaesthesia for dysautonomic diabetic patients with diabetic foot ulcer going for wound debridement, Ray's amputation and below knee amputation (5) Many studies have compared multiple perioperative parameters of patients undergoing lower limb surgery under peripheral nerve blocks versus spinal anaesthesia. These parameters include preparation time, anaesthetic complications (e.g. hypotension, nausea and vomiting, post-dural puncture headache, urinary retention), patient satisfaction and postoperative pain control (6,7,8). The investigators want to study if patients with dysautonomia have a different haemodynamic response to spinal anaesthesia or peripheral nerve blockade changes compared to patients with normal autonomic function. Secondarily, the investigators would also study if there is a difference in post operative pain control as well as incidence in chronic pain in patients who receive spinal anaesthesia versus peripheral nerve blockade.

Dysautonomia refers to the abnormal function of the autonomic nervous system including sympathetic and parasympathetic nervous system. Diabetes mellitus causes secondary dysautonomias (1). The Survey of Autonomic Symptoms (SAS) is a simple and validated tool to assess the presence and severity of autonomic symptoms (2). Diabetic patients also suffer from chronic neuropathic pain. After amputation surgeries, up to 78% of these patients may develop post surgical neuropathic pain (3). The self-report version of the Leeds Assessment of Neuropathic Symptoms and Signs pain scale (S-LANSS) is validated as a diagnostic tool to assess patients with neuropathic pain (4). This scale will be used to assess if there is any changes in the pain experienced after diabetic foot surgery. Currently, both spinal anaesthesia (SAB) and ultrasound guided femoral and/or sciatic peripheral nerve blocks (FSNB) are acceptable anaesthesia for dysautonomic diabetic patients with diabetic foot ulcer going for wound debridement, Ray's amputation and below knee amputation (5) Many studies have compared multiple perioperative parameters of patients undergoing lower limb surgery under peripheral nerve blocks versus spinal anaesthesia. These parameters include preparation time, anaesthetic complications (e.g. hypotension, nausea and vomiting, post-dural puncture headache, urinary retention), patient satisfaction and postoperative pain control (6,7,8). The investigators want to study if patients with dysautonomia have a different haemodynamic response to spinal anaesthesia or peripheral nerve blockade changes compared to patients with normal autonomic function. Secondarily, the investigators would also study if there is a difference in post operative pain control as well as incidence in chronic pain in patients who receive spinal anaesthesia versus peripheral nerve blockade.

Sciatic with or without femoral block performed either with ultrasound and/or nerve stimulator on the patient with 3mg/kg of ropivacaine

Blood pressure or heart rate changes more than 30% of baseline after spinal or block is considered significant

Inclusion Criteria: Diabetic patients with diabetic foot ulcer undergoing diabetic foot surgery below the knee Exclusion Criteria: Refuse spinal or regional anaesthesia Uncooperative patients Patients with contraindication for FSNB or SAB Patients with known allergy to local anaesthetics

Lai HY, Foo LL, Lim SM, Yong CF, Loh PS, Chaw SH, Hasan MS, Wang CY. The hemodynamic and pain impact of peripheral nerve block versus spinal anesthesia in diabetic patients undergoing diabetic foot surgery. Clin Auton Res. 2020 Feb;30(1):53-60. doi: 10.1007/s10286-017-0485-8. Epub 2017 Dec 1.