48 Threading the Needle: A Review of Lumbar Puncture Success Rates in a Resident-Driven Procedure Team

Abstract

Lumbar puncture (LP) has been one of the few invasive tests performed in the emergency department with both a diagnostic and therapeutic role in the treatment of such diseases as meningitis, GBS, NPH, and pseudo tumor cerebri. The anatomic landmark based procedure for obtaining cerebral spinal fluid (CSF) is a skill set with a steep learning curve prior to procedural competence. Yet, despite this learning curve, insufficient literature explores the success rate of lumbar puncture in adult patients. At our institute, we created the resident-operated Procedure Team which performs invasive procedures includes lumbar puncture, midline catheters, ultrasound-guided peripheral vascular access, and paracentesis. We plan to examine the baseline success rate of lumbar punctures (LP) performed by our procedure service compared to the existing data in the current literature. We performed an extensive literature review looking at a combination of retrospective, prospective, meta-analysis, and systemic reviews that reported percent success of LPs using the standard palpation technique utilizing anatomic landmarks. After obtaining this data, we conducted a retrospective chart review of all orders that were placed for LP to be performed by the Procedure Team from January 1st, 2016 until October 28th, 2018. We defined success as collection of at least 2 cc of CSF. The studied patient population included inpatient adults in the age range of 18-99 years. After performing a literature review of studies in neurology clinics and pediatric emergency departments, we found a success rate that ranged from 72%-74%. The only meta-analysis performed showed a success rate of 92%; however, most studies included in the meta-analysis utilized a young, healthy obstetric patient population undergoing epidural catheterization/LP by anesthesiology. After a chart review of the data at our institution, 135 LPs performed. Of those 135 LPs performed, 41 failed attempts were documented resulting in a success rate of 69.6%. Further subgroup analysis determined there was no statistically significant difference in age >60 and <60 between the successful LP group when compared to the failed LP group. There was a statistical significance difference between the body mass index BMI>30 and less than BMI<30 groups Based on the comparison between our literature review and our retrospective chart review, our institution appears to achieve LP success rate comparable to published rates. Furthermore, BMI seems to play a significant role in LP success. We believe more studies should be conducted with larger sample sizes to estimate the true LP success rates among adult patients. This data regarding rate of success and factors that can affect the rate of success may be utilized when obtaining informed consent. Additionally, it can provide a baseline when making comparisons with other procedural approaches to LP including the use of ultrasound.