Comparison of different patient positions for neuraxial access: a randomised controlled study

Patient positioning during administration of spinal anesthesia is very important. Poor positioning may cause repeated spinal needle insertions and increase the risk of back pain, post-dural puncture headache (PDPH), epidural hematoma, and neural trauma. The sitting position is frequently used for patients undergoing spinal anesthesia, especially when low lumbar and sacral levels of sensory anesthesia are needed for the surgical procedure. The most important point for performing a neuraxial block in a sitting position is reducing lumbar lordosis, resulting in easier access to the intervertebral space; on the other hand, lumbar flexion pushes the thecal sac into a more superficial position. There are a few studies comparing different sitting positions including a traditional sitting position (TSP), forward bending or hamstring stretch position (HSP) and squatting position (SP) for reversing the lumbar lordosis and improving access to intervertebral space for neuraxial block. However, there are very few studies which have used a mayo trolley for supporting the upper body with the legs in pendant position while administering the spinal anaesthesia. In this study, we investigate if neuraxial anaesthesia has higher success rate when patients are positioned while sitting with legs in pendant position and upper body supported with the aid of a Mayo-trolley (Mayo-trolley pendant position) to administer when compared to patients positioned in sitting position while hugging a pillow (traditional sitting position).