Pre-procedural Ultrasound Techniques Versus Conventional Landmark Technique of Spinal Anesthesia in Elderly Patients

A Randomized Controlled Trial of Pre-procedural Ultrasound Techniques Versus the Conventional Landmark Technique of Spinal Anesthesia in Elderly Patients

Traditionally, spinal anesthesia is performed using the palpation of bony landmark to identify the level and point of entry of the spinal needle. Recently, ultrasound imaging has become an increasingly popular procedure among anesthesiologists to guide neuraxial blockade. Most of the studies on pre-procedural ultrasound-guided neuraxial techniques are limited to a midline approach using a transverse median views. The parasagittal oblique view consistently offers better ultrasound view of the neuraxis compared to the transverse median view. However, it is still not evident whether these superior parasagittal oblique views will lead to an easier paramedian needle insertion. In the literature, there are no studies directly comparing the US-guided paramedian approach using the parasagittal oblique (PSO) view, the US-guided midline approach using the transverse median view, and the conventional landmark midline approach to perform spinal anesthesia in the elderly patients, in particular for the teaching of novice anesthesia residents.

The aim of this study is to find out the optimal technique to perform spinal anesthesia by residents in training. Thus the investigators will compare preprocedural ultrasound-guided paramedian technique using parasagittal oblique view vs preprocedural ultrasound-guided midline technique using transverse median view vs landmark-guided midline technique of spinal anesthesia in the elderly population. Our hypothesis is that both preprocedural US-guided techniques are superior to the conventional landmark-guided midline technique with regard to ease of performance defined as success rate at first attempt, number of puncture attempts, spinal procedure time, and patient satisfaction.

Inclusion Criteria:

• Patients scheduled for surgery amenable to spinal anesthesia, aged more than 60 years, with American Society of Anesthesiologists physical status 1 to 4.

Exclusion Criteria:

• Patients who are unable to give consent, refuse spinal anesthesia, have spinal abnormalities (including scoliosis and previous spine operations with instrumentation) or have contraindications to spinal anesthesia, including allergy to local anesthetics or a bleeding diathesis