Evaluation of Safety of Spinal Anaesthesia in Patients Receiving Perioperative Antithrombotic Therapy Undergoing Infrainguinal Revascularisation Surgeries: A One-Year Prospective Clinical Research

Objective: To evaluate anaesthetic outcome, patient outcome and timing of perioperative antithrombotic therapy in relation to intrathecal injection in patients undergoing infrainguinal revascularisation surgery, for peripheral artery disease (PAD) in spinal anaesthesia.Material and Methods: A one-year prospective observational study was conducted; from May 2019 to May 2020, in a tertiary care centre. This included all consecutive patients undergoing infrainguinal revascularisation surgery for PAD under spinal anaesthesia. Preoperative antithrombotics were stopped, as per standard guidelines, to achieve a normal coagulation profile before spinal anaesthesia. Perioperative data related to the patients, antithrombotics, anaesthesia, surgery, and complications were recorded. Primary outcomes measured were anaesthetic outcome in terms of spinal success and spinal safety. Secondary outcomes measured were timing of perioperative antithrombotic therapy in relation to intrathecal injection and patient outcomes defined as: good, morbidity or mortality.Results: A total of 102 patients were evaluated, with a mean age of 54.69±16.36 years (91% males, 9% females): 58% had medical comorbidities. A single dose of intravenous (IV) unfractionated heparin (5,000-7,500 IU) was given intraoperatively at 24.97±3.69 minutes after intrathecal injection. Anaesthetic outcome was good in all patients; in terms of spinal safety (100%), as none of the patients developed spinal related complications. All had spinal success (100%), as no patient required conversion to general anaesthesia. Postoperatively, 98% (100) of patients had good outcomes, and mortality only occurred in 2% (2) of patients.Conclusion: Spinal anaesthesia is safe and effective for infrainguinal revascularisation surgery. If the patient has a normal preoperative coagulation profile, and the timeline to stop antithrombotic therapy is strictly followed, administration of IV unfractionated heparin (5,000-7,500 IU); at approximately 25 minutes after intrathecal injection, was found to be safe.