Lumbar Puncture Utilization Trends Across a Tertiary Health Care System

The rate of lumbar puncture (LP) in EM practice may be decreasing in recent years. The extent of this shift has not been well investigated and has implications for EM training and practice. Our objective was to assess trends in LP utilization by individual departments over a 13 year period across a University health system.

We performed a retrospective study at a single academic health system encompassing the calendar years of 2012 to 2024. The LP current procedural technology (CPT) codes were used to identify each LP event. LPs were allocated to a given department based on the specialty of the attending physician. Data was abstracted using a standardized data abstraction instrument by two trained study investigators. Temporal changes in LP utilization amongst departments were evaluated by comparing three prespecified time periods, 2012-2015 (Era 1), 2016-2020 (Era 2), and 2021-2024 (Era 3). A Poisson regression model was used to calculate incidence rate ratios (IRRs) amongst departments and the Chi-squared test was used to assess change in proportion of ED LPs between time eras.

There were 9,887 total LPs performed across the health system during the 13 year time period. The average annual LP volume was 761, with a mean increase of 1.7% each year. Radiology demonstrated the largest growth, with mean annual LP volume increasing from 281 LPs/year in Era 1 to 428 LPs/year in Era 3, corresponding to a 53% increase (IRR 1.53; p < 0.001). In contrast, ED LP volume declined slightly, decreasing from 120 LPs/year in Era 1 to 109 in Era 2 and 103 in Era 3. This represents a 14% reduction in ED LP volume from Era 1 to Era 3 (IRR 0.86; p = 0.017). Internal Medicine, Pediatrics, and Neurology each demonstrated increasing LP volume across eras, with Internal Medicine (IRR 2.67) and Pediatrics (IRR 3.56) showing large increases, and Neurology exhibiting a modest rise (IRR 1.26), all comparing Era 3 with Era 1 (all p ≤ 0.001).The ED proportion of all LPs performed in the health system decreased from 17.7% to 12.8% from Era 1 to Era 3 (χ² = 31.8, p < 0.001).

ED LP volume decreased slightly during the 13 year study period, while overall health system LP volume increased. The share of LPs performed by EM physicians decreased over time, while other specialties increased. In the latest era, nearly half of LP procedures were performed by Radiology. Additional training resources may be needed to maintain EM physician exposure to LP.