Ultrasound Guided Landmark Identification for Spinal Anesthesia for Patients with Spinal Abnormality

Spinal anesthesia using a surface landmark?guided technique can be challenging in patients with anatomical abnormalities of spine. We assessed whether an ultrasound-assisted technique could reduce the number of needle passes required for block success compared with the landmark-guided technique in patients with abnormal spinal anatomy. Forty patients with abnormal spinal anatomy underwent spinal anesthesia either surface landmark?guided or preprocedural ultrasound?assisted. All spinal procedures were performed by 1 experienced anesthesiologist. The primary outcome was the number of needle passes required for successful dural puncture. Secondary outcomes included the success rate on the first pass, total procedure time, periprocedural pain scores, and the incidences of radicular pain, paresthesia, and bloody tap or any adverse effects during the neuraxial procedure. The number of needle passes was significantly lower in the ultrasound group than in the landmark group. First-pass success was achieved more in patients who underwent pre-procedural scan with ultrasound than in landmark guided technique. The total procedure time, defined as the sum of the time for identifying landmarks and performing spinal anesthesia, did not differ significantly between the two groups. The ultrasound group showed lower periprocedural pain scores compared with the landmark group. The incidences of complications during the procedure showed no significant differences between the two groups. The use of ultrasound significantly reduces the technical difficulties of spinal anesthesia in patients with abnormal spinal anatomy compared with the landmark-guided technique. Our results suggests the use of neuraxial ultrasonography for spinal anesthesia in such patients.