Position and Angle Marking System (PAMS) for Ultrasound-guided Neuraxial Procedures
Epidural anaesthesia involves the administration of numbing medication (local anaesthetics) close to the spinal canal, and is regarded as the best method for providing pain relief during labour and childbirth. The use of ultrasound to guide epidural insertion and placement has been shown to improve pain relief and reduce the risk of complications. However, after identifying the desired needle insertion site via ultrasound, current practice involves demarcating the insertion site using marker pens, which is time-consuming, inaccurate, and may be inadvertently removed by skin sterilisation. Furthermore, the desired needle angulation determined by ultrasound cannot be accurately measured and maintained during the epidural procedure. Both issues limit the benefits of using ultrasound to guide the epidural procedure. To address these issues, the investigators developed a Position and Angular Marking System (PAMS) that attaches on to the ultrasound probe. When the desired insertion site is identified by ultrasound, the doctor gently presses PAMS into the patient's back to create skin indentations demarcating the needle insertion point. These indentations are not affected by skin sterilisation, and may improve accuracy and reduce the time taken to perform the epidural procedure. Next, the angle between the ultrasound probe and the patient's back can be measured using PAMS, and this angle can be maintained using a needle guide during the epidural procedure. The purpose of this randomised study is to evaluate the usability of PAMS and to identify areas for further improvement. This study will involve up to 10 healthy simulated patients, and up to 30 volunteer ultrasound operators. After undergoing a standardised training session with a mannequin, the ultrasound operators will be randomly assigned to perform skin marking on the simulated patients as though they are performing an ultrasound-guided epidural anaesthesia procedure (no needle puncture will be made) using either PAMS, or standard clinical practice with marker pens. After completing the procedure, the ultrasound operators will cross over and perform the procedure again using either PAMS or standard clinical practice with marker pens. Both the ultrasound operators and simulated patients will be asked to complete satisfaction and usability surveys regarding their experience with the procedures.
• Trained in the use of ultrasound-guided neuraxial procedures
• Healthy, no significant medical comorbidity (American Society of Anesthesiologists Physical Status I or II)
• No spinal abnormalities, or previous spinal surgery