Objective: To evaluate pediatric emergency department (ED) provider lumbar puncture success with and without the Compass Lumbar Puncture Enhanced, a new pressure transducer, in order to determine: the proportion of lumbar punctures (LPs) where a) any cerebrospinal fluid (CSF) is obtained on the first attempt, b) any CSF is obtained on any attempt, and c) sufficient CSF is obtained for standard tests (culture, chemistries, cell count); the time to provider success in obtaining a) a drop of fluid from the needle, and b) opening pressure measurement; the proportion of successful lumbar punctures that contain blood; and provider satisfaction.

Background: Lumbar punctures are necessary to diagnose meningitis, neurological diseases and some cancers. They are common pediatric emergency department procedures that frequently require repeated attempts or are only partially successful, with sufficient blood to limit interpretation. Measuring cerebrospinal fluid pressure during a lumbar puncture is recommended but rarely done, due to limitations of current technology. Liquid column manometry is cumbersome, time-consuming and frequently impractical. Existing pressure transduction probes that connect via tubing to external monitors are not designed or recommended for LPs. The pressure is displayed on a monitor that is difficult to view during the lumbar puncture procedure and they equilibrate too slowly to keep pace of pressure changes during lumbar puncture. The Compass Lumbar Puncture Enhanced is a new, inexpensive, disposable, medical device, specifically designed for use during lumbar punctures, that has the potential to increase lumbar puncture success and decrease blood contamination. It attaches to the spinal needle and displays both a numeric pressure value and a pressure waveform, allowing physicians to more readily identify the cerebrospinal fluid space and measure cerebrospinal fluid pressure. The device is small, easy to use, and readily incorporated into standard practice.

Methods: This randomized clinical trial will test adding the Compass Lumbar Puncture Enhanced vs. standard care in 60 children 0-16 years old who are receiving a lumbar puncture in the Seattle Children's Hospital Emergency Department. We will test the Compass Lumbar Puncture Enhanced against standard care in 60 children receiving lumbar puncture, comparing success, pressures obtaining, time to success, complications (e.g. \>200 red blood cells/mm3) and provider satisfaction. Results will be compared with chi-squared tests, regressions, Kaplan-Meier and logrank tests. We expect improved success, decreased time to success and complications and high provider satisfaction.

Impact: Currently, one third of lumbar punctures require multiple attempts, 7-20% contain blood that limits interpretation, and 6% are unsuccessful. This results in unnecessary hospitalizations, increased hospital days, increased antibiotic use and increased numbers of repeat procedures. The Compass Lumbar Puncture Enhanced uniquely provides immediate feedback about pressure that will allow physicians to more quickly and confidently identify the cerebrospinal fluid space, and instantly determine cerebrospinal fluid pressure when the space is reached. We believe the Compass Lumbar Puncture Enhanced will increase lumbar puncture success and decrease the proportion containing blood. It has the potential to become the standard of care and be used in every lumbar puncture procedure. This study is expected to demonstrate the clinical utility of the Compass Lumbar Puncture Enhanced to the medical community.