Increased lumbar puncture success using a paramedian approach: A retrospective cohort study

Lumbar puncture (LP) is frequently necessary in hospitalized patients for diagnostic and therapeutic purposes. Traditional landmark identification by palpation of the lumbar spine and pelvis can see significant failure rates. A paramedian approach is an accepted, though less frequently used technique associated with higher success rates for spinal access in anesthesia when aided by ultrasound. Similarly, point-of-care ultrasound (POCUS) of the paramedian acoustic window may help guide a paramedian LP technique.

To compare the probability of success before and after the implementation of a standardized training curriculum for lumbar punctures (LPs) performed by the Hospital Medicine Procedure Service (HMPS).

The HMPS at the University of Minnesota Medical Center (UMMC), a large tertiary academic medical center, implemented a standardized training for an ultrasound-assisted paramedian (USPM) approach to all bedside lumbar punctures (LPs) and then conducted a retrospective review comparing success rates between the traditional midline (ML) and USPM approaches.

A total of 269 LPs were performed on hospitalized patients. Before standardization, the probability of a successful LP was 72.6% using ML approach. After standardization, using a USPM approach, the probability of a successful LP was 85.4%. The probability of a successful procedure was 13.6 (95% confidence interval: 2.8, 24.4, p = .014) percentage points higher for the USPM approach when compared to the ML approach and accounting for sex, age, BMI, and if the LP was for chemotherapy.

Institutions with a HMPS should consider transitioning to use of the USPM approach for bedside LPs, which is associated with a higher probability of success and reduced utilization of more resource-intensive hospital services, such as Interventional Radiology or Neuroradiology.