Comparison of Ultrasound-Marked Versus Standard Lumbar Puncture Success in Infants

The aim of this study was to compare ultrasound (US)-marked versus standard lumbar puncture success in infants.

This was a prospective cohort study at an academic pediatric emergency department. Standard lumbar puncture success in a retrospective control was compared with success in a US-marked group. Spinal US was performed with infants in the sitting and lateral decubitus position to identify the interspinous space with the most cerebrospinal fluid. The optimal position was determined, and this space was marked. The proceduralist performed the lumbar puncture at the level of the markings. The primary outcome was a successful lumbar puncture by the first provider, defined as a collection of cerebrospinal fluid with less than 1000 red blood cells/mm3. Secondary outcomes were successful lumbar puncture after attempts by more than 1 provider and collection of any spinal fluid.

Between June 2017 and April 2019, we enrolled 284 infants younger than 12 months, 210 in the retrospective standard group and 74 in the prospective US-marked group. Baseline characteristics of both groups were similar. The primary outcome showed no difference between US-marked group and control (38% vs 36%; difference: 1.6% [95% confidence interval (CI), -14.7 to 10.7]). Secondary outcomes showed no significant success differences by more than 1 provider (51% vs 39%; difference: 12.8% [95% CI, -25.7 to 0.3]) or in obtaining any spinal fluid (82% vs 79%; difference: 3.9% [95% CI -13.3 to 7.5]).

There were no differences in success between US-marked and standard lumbar punctures in infants by different providers.