Abstract
Background
Lumbar puncture (LP) is one of the most common procedures performed in pediatric emergency departments worldwide. Despite its frequency and utility, first time success rates remain low and traumatic LP rates remain high. A modality that has been proposed to improve such outcomes is ultrasound. Several pediatric-specific studies have evaluated ultrasound for LP, but had limited study sonographers, small sample size, and included primarily or solely neonatal patients. For these reasons, our study aimed to evaluate the use of ultrasound-assistance for pediatric LP in a more practical, generalizeable manner in the emergency department setting.
Objectives
The aim of this study was to determine if emergency physician performed ultrasound-assisted lumbar puncture improves first-time success rates in a pediatric population in comparison to standard landmark-based approach.
Design/Methods
This was a multi-centered, prospective randomized controlled conducted in 2 tertiary care, pediatric, university-affiliated emergency departments between June 2017 and October 2018. Eligible participants were all children younger than 19 years of age requiring a lumbar puncture as part of their emergency department work-up and were randomized to either the standard landmark-based lumbar puncture (SLP) or ultrasound-assisted lumbar puncture (UALP) groups. In the intervention group, a physician performed a static pre-procedural ultrasound of the spine to identify and mark the level of the conus medullaris and preferred puncture site prior to LP. Our primary outcome was the first-time lumbar puncture success rate as defined by the presence of at least 0.5mL of cerebrospinal fluid with red blood cell count < 1,000/mm3. All outcomes were evaluated using an intention-to-treat analysis.
Results
166 patients were enrolled, with 84 in the UALP and 82 in the SLP group. The baseline characteristics of the children, care providers, and procedure were similar in both groups. A total of 23 physicians performed ultrasounds in the study. The proportion of successful first-time LP was higher in the ultrasound group (60/84; 68%) than for the standard procedure (52/82; 60%). However, this failed to reach statistical significance (difference: 8.1%; 95% CI: -6.4 to 22.2). The number needed to treat is 13 ultrasounds to avoid one unsuccessful first-time LP.
Conclusion
Ultrasound use in pediatric emergency lumbar puncture is a viable procedural option and has potential benefit with low risk.