P020 Microdose via continuous spinal catheter in high-risk patient undergoing prolonged orthopedic surgery

<h3>Background and Aims</h3> Continuous spinal anaesthesia (CSA) offers a valuable alternative for high-risk patients undergoing major lower limb surgery. In elderly patients with significant cardiovascular comorbidities, conventional neuraxial blocks carry a high risk of hemodynamic instability. CSA offers a valuable alternative by allowing precise dose adjustment. Reducing sympathetic blockage and minimizing hypotension events. This case illustrates the use of ultra-low dose CSA in an ASA IV patient with multiple cardiopulmonary comorbidities undergoing osteosynthesis for a periprosthetic femoral shaft fracture. <h3>Methods</h3> An 86-year-old woman with severe valvular heart disease, pulmonary hypertension, and ischemic cardiomyopathy was scheduled for osteosynthesis of a periprosthetic femoral fracture. A suprainguinal fascia iliaca block was performed preoperatively. CSA was initiated via a 20G intrathecal catheter at L3-L4. An initial intrathecal injection of 1.5 mg isobaric bupivacaine with 5 mcg fentanyl was administered, followed by two further boluses of the same dosage at one-hour intervals (total bupivacaine dose: 4.5 mg, total surgical time 202 minutes). Sensory level was evaluated using both temperature discrimination and pinprick test. Hemodynamics were continuously monitored via radial arterial line and Vigileo® system. <h3>Results</h3> CSA provided satisfactory surgical conditions. Hemodynamic parameters remained stable throughout. Estimated blood loss was 350 mL; no transfusions were required intraoperatively. No adverse events noted during postoperative recovery. <h3>Conclusions</h3> CSA using ultra-low dose bupivacaine appears to be a safe and effective option for high-risk elderly patients. Compared to traditional spinal approaches, this strategy enabled precise adjustment of local anesthetic dosing, reducing hypotensive events during prolonged surgical procedures. The use of complementary regional blocks enables lower intrathecal requirement.