Ultrasound-assisted Lumbar Punctures: A Systematic Review and Meta-Analysis.

Background: Lumbar punctures (LPs) are a common procedure in emergency medicine. However, studies have found that failed procedure rates can be as high as 50%. Ultrasound has been suggested to improve success rates by visually identifying the location and trajectory for the LP procedure. This systematic review and meta-analysis was performed to determine whether the use of ultrasound improved the rate of successful LP performance.

Methods: PubMed, CINAHL, Scopus, LILACS, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and bibliographies of selected articles were assessed for all randomized controlled trials comparing the success rates of ultrasound-assisted LP with landmark-based LP. Secondary outcomes included the rate of traumatic LPs, time to procedural success, number of needle passes, and patient pain score. Data were dual extracted into a predefined worksheet, and quality analysis was performed using the Cochrane Risk of Bias tool. Data were summarized and a meta-analysis was performed with subgroup analyses by pediatric versus adult patients and by operator training level.

Results: Twelve studies (n = 957 total patients) were identified. Ultrasound-assisted LP was successful in 90.0% of patients and landmark-based LP was successful in 81.4% of patients. The calculated risk difference (RD) was 8.9% (95% confidence interval [CI] = 1.2% to 16.7%) with an odds ratio (OR) of 2.22 (95% CI = 1.03 to 4.77) in favor of the ultrasound-assisted group. There were fewer traumatic LPs in the ultrasound-assisted group (10.7% vs. 26.5%; RD = -16.4%, 95% CI = -27.6% to -5.2%; OR = 0.28, 95% CI = 0.18 to 0.45). Ultrasound-assisted LP was also associated with a shorter time to successful LP (6.87 minutes vs. 7.97 minutes), fewer mean needle passes (2.07 vs. 2.66), and lower patient pain scores (3.75 vs. 6.31).

Conclusions: Ultrasound-assisted LPs were associated with higher success rates, fewer traumatic LPs, shorter time to successful LP, fewer needle passes, and lower patient pain scores. Ultrasound should be considered prior to performing all LPs, especially in patients with difficult anatomy. Further studies are recommended to determine whether this effect is consistent in both adult and pediatric subgroups, as well as the impact of transducer type and body habitus on this technique.