Does Pre-Procedure Neuraxial Ultrasound Using the GE Logiq® Improve Midline Placement of Combined Spinal Epidural when Compared to a Palpation Technique Performed by Experienced Anesthesiologists? A Prospective Randomized Study

Background: Neuraxial placement relies on palpation of anatomical landmarks, sometimes challenging to identify. Ultrasound (US) has helped facilitate those procedure. We wanted to assess efficacy of the US compared to landmark techniques when used by experienced obstetric anesthesiologists.

Methods: We conducted a randomized prospective trial of healthy parturients requesting neuraxial labor analgesia. Positive CSF through the 27 G Pencan spinal needle at the first interspace attempted was the primary outcome. Secondary outcomes were the number of attempts and the number of needle adjustments within a space, presence of symmetrical analgesia 2 hours after placement, and need for epidural replacement. The procedures were performed by practitioners experienced in obstetric anesthesia, including obstetric anesthesiology fellows, and attending physicians who received a video training of the US technique prior to the study [1].

Results: Forty-eight patients were randomized to either the US or landmark group. Two patients (one in each group) were excluded from the study due to delivery within 2 hours of CSE (Combined Spinal Epidural) placement. One patient in the landmark group was excluded due to a wet tap. No statistical difference was found regarding positive CSF flow on first attempt at CSE (p = 0.6). All secondary outcomes were statistically insignificant as well: number of spaces attempted (p = 0.71 95% CI –0.30 to 0.21), number of needle adjustments (p = 0.09, 95% CI –0.10 to 1.28), presence of symmetrical anesthesia at 2 hours (p = 1) and need for epidural replacement (p = 0.48).

Conclusions: When placed by an experienced obstetric anesthesiology fellow or attending physician, there is no difference in the successful placement of CSE with US versus landmark technique.

Key Points Summary

Question: Does the use of an US machine (GE Logiq®) by experienced obstetric anesthesiology providers increase the success of neuraxial placement compared to the ‘traditional’ landmark technique.

Findings: Our results did not show any statistical difference between the US and the landmark techniques when done by skilled anesthesiologists in term of the number of interspaces attempted, number of adjustments or redirections of the needle in the same interspace, the presence/absence of CSF flow upon dural puncture or the adequacy of the block 2 hours after placement.

Meaning: We concluded that the use of US does not confer any benefits for neuraxial placement in this specific subgroup of practitioners.