Feel It, See It, Get It: Is Internal Medicine Residents’ Use of Ultrasound in Lumbar Puncture Associated With Higher Success Rate?

Introduction: Multiple emergency medicine and anesthesiology research studies suggest that ultrasound (US) is potentially useful in assisting with needle insertion in a lumbar puncture (LP). However, little is known about its value when utilized by internal medicine (IM) residents. The objective of this study is to examine whether the use of ultrasound in LPs performed by internal medicine residents is associated with a higher success rate than the traditional palpation method. Materials and Methods: We reviewed all LP procedure notes in our hospital's records written by IM residents from June 2017 to December 2018 in a single community teaching hospital. We examined the association between the US use and success using the Chi-squared test and logistic regression model. Results: Among the 152 lumbar punctures documented, 130 specified whether US was used or not. Among these, 39 were ultrasound-assisted and 91 were not. Use of ultrasound was associated with a higher success rate compared to the non-ultrasound-use (87% vs 73%; p=0.1). The association was strengthened using logistic regression but did not reach statistical significance (OR 3.5; CI: 0.9 -13.8; p=0.07). Success was significantly associated with a fewer number of attempts (p<0.001). No statistically significant association was found between success and patients’ body mass index (BMI; p=0.57), or level of training (p=0.11). Conclusions: Use of ultrasound for needle insertion in lumbar punctures performed by internal medicine residents was associated with a higher success rate compared to the palpation method but without statistical significance. Ultrasound is a non-invasive, quick, and safe tool. Our study favors its use as an aid during lumbar puncture when performed by internal medicine residents. Larger studies are needed to gather more evidence in support of this conclusion.