Spinal Anaesthesia

Neuraxial blockade is commonly performed using a manual palpation technique, but the procedure can be challenging, particularly in patients with high body mass index, pregnancy, or spinal deformities. Preprocedural ultrasound may improve identification of the optimal injection site, yet its use in clinical practice remains limited, partly due to a lack of structured training. This multicentre randomised controlled trial investigates whether anaesthesiologists performing ultrasound-assisted spinal anaesthesia achieve better clinical outcomes and higher patient satisfaction compared with the traditional manual palpation technique. Both novice anaesthesia residents and more experienced anaesthesiologists are included. Participants receive structured simulation-based training using either ultrasound-assisted or manual palpation techniques, following a mastery learning approach with predefined performance standards. After certification, participants perform spinal anaesthesia during elective lower limb surgery, with clinical performance assessed by senior anaesthesiologists. The primary outcome is first-attempt success of spinal block. Secondary outcomes include number of attempts, needle redirections, time spent, need for assistance, and overall block success. Patient satisfaction and complications are assessed as tertiary outcomes. This study aims to provide evidence on the clinical effects of structured training in ultrasound-assisted neuraxial access and to explore the role of prior clinical experience.

Ambulatory surgery places high demands on anesthetic technique. rapid onset and offset of anesthesia, rapid recovery of protective reflexes, mobility and micturition, are required. Since the inception of ambulatory surgery, the favored anesthetic technique has been general anesthesia with short-acting drugs. Concerns about the time to perform spinal anesthesia and the risks of prolonged motor block and urinary retention have limited its use. Alpha-blockers, lavage fluids for epidural space, insulin, and intravenous lipid emulsions, are still being discussed to shorten and reverse adverse effect of different LAs used for spinal anaesthesia, hence we will evaluate the effectiveness of intravenous lipid emulsion for reversing the neural blockade of spinal anaesthesia in patients undergoing ambulatory surgery.

Neuraxial ultrasonography has been shown a safe and effective technique to enhance the overall success rate of lumbar puncture and reduce the number of injection attempts. However, the current blind palpation landmark technique is known to be highly inaccurate and may increase the risk of multiple insertion attempts, patient suffering and complication rates such as spinal cord injury. Various clinical studies have confirmed the effectiveness of ultrasound imaging compared with the traditional palpation method. However, none of the present system can achieve real-time guidance. The overall aim of this proposal is to develop an ultrasound guided automated spinal landmark identification with real-time neuraxial needle insertion system (uSINE) to improve patient safety and efficacy of neuraxial procedure needle insertion success. This will be achieved in 4 phases of technology development and clinical trial phases. The investigators will recruit 20 subjects in a prospective cohort study to investigate the spinal needle first attempt success rate as a clinically relevant outcome. The secondary aim is to develop an automated spinal landmark identification algorithm using image processing to identify spinal landmarks in 50 obese patients. Third phase objective will be to obtain clinical data, and evaluation and annotation of the clinical data of spinal ultrasonography in 65 obese patients (BMI \> 30kg/m2), whereas the fourth phase will measure the uSINE identification accuracy and first-attempt puncture success rate of uSINE in a clinical study of 65 obese patients (BMI \> 30kg/m2).