Preprocedural ultrasound assessment does not improve trainee performance of spinal anesthesia for obstetrical patients: a randomized controlled trial

Turkstra T, Marmai K, Armstrong KP, Kumar K, Singh SI. Journal of Clinical Anesthesia. 2017 Feb; 37: 21-24.


  • Population measured was composed of junior residents performing spinal anesthesia on 80 obstetric patients.
  • Intervention was a preprocedure ultrasound (U/S) examination.
  • For spinal anesthesia, key outcomes measured were number of attempts and duration.
  • Preprocedure U/S examination did not reduce the number of attempts for spinal placement.
  • U/S examination did not improve the perceived ease of performing spinal anesthesia.


Study objective

This randomized controlled trial was designed to evaluate the efficacy of additional information from preprocedure ultrasound examination to aid anesthesiology trainees performing spinal anesthesia for obstetric patients.


Trainee residents were randomly allocated to landmark technique and anatomy demonstration via ultrasound examination or landmark technique only for spinal anesthetic placement.


The primary outcome was the number of attempts for the spinal anesthetic. Secondary outcomes included placement duration; block height; and the incidence of need for staff intervention, paresthesia, and bloody tap. Subjective ease of placement was rated on a 100-mm visual analog scale.

Main results

Baseline demographic data were similar between the patient groups. The median number of attempts with preprocedure ultrasound and landmark was 3 (interquartile range, 2-7). This was not significantly different from the number of attempts with landmark technique only of 3 (1-60) (P = .69). The median duration of spinal placement with ultrasound and landmark was 92 (51-140) seconds vs 75 (53-126) seconds with landmark only (P = .57). There was no statistical difference between the groups in spinal placement duration, need for staff intervention, paresthesia, bloody tap, lumbar interspace, or block height. There was no difference in subjective ease of spinal placement by the resident.


In this study of junior anesthesia trainees performing obstetrical spinal anesthesia with preprocedure ultrasound and landmark technique or landmark technique only, no significant difference was observed in the number of attempts, duration of spinal placement, subjective ease of spinal placement, or any other measured secondary outcome.

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