In summary, for patients who receive atraumatic needles:

Benefits in NNT

    6.8% lower risk of post-dural puncture headache with an atraumatic needle
    1 in 14 were helped (avoided post-dural puncture headache)

Harms in NNT

    No one was harmed
    No one was harmed

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Source: Nath S, Koziarz A, Badhiwala JH, Alhazzani W, Jaeschke R, Sharma S, et al. Atraumatic versus conventional lumbar puncture needles: a systematic review and meta-analysis. Lancet. 2018 Mar 24;391:1197-1204.

Study Population: 110 trials comprising 31,412 patients receiving a lumbar puncture

Efficacy Endpoints: Post-dural puncture headache, traumatic tap, success on first attempt, failure rate

Harm Endpoints: Traumatic tap, need for epidural blood patch, nerve root irritation, hearing disturbance, backache

Narrative: Over 350,000 lumbar punctures (LP) are performed in acute care settings each year in the United States.1 Post-dural puncture headache (PDPH) is one of the most common complications after an LP, occurring in approximately 11% of patients,2 with one study reporting an occurrence rate of up to 36%.3 While PDPH has been attributed to multiple factors, needle tip design has been frequently investigated as a potential cause.2 It has been suggested conventional needles may cause larger lacerations in the dural fibers compared to atraumatic needles, increasing the degree of cerebrospinal fluid leakage.4 However, it is important to determine whether needle tip design influences the rate of PDPH.

This systematic review and meta-analysis included 110 randomized controlled trials (n = 31,412 patients) comparing atraumatic needles with conventional needles for LP.2 The authors excluded epidural injections. The primary outcome was the incidence of PDPH.

The mean age of participants was 29 years, and 62% were women. The majority of LPs were performed for anesthesia, with only 5.4% performed for diagnosis. The incidence of PDPH was lower in the atraumatic versus conventional needle group (4.2% vs 11%; relative risk: 0.4, 95% confidence interval CI: 0.3 to 0.5; absolute risk difference: 6.8%; number-needed-to-treat: 14). However, there was no statistically significant difference in the incidence of traumatic tap, success on the first attempt, or overall failure rate. Other harm end points such as need for epidural blood patch, nerve root irritation, hearing disturbance, and backache were similar between the groups.

Caveats: This systematic review and meta-analysis has several important limitations. There was significant heterogeneity among included studies with regard to the needle type and training of the person performing LP. Of note, nearly half of the LPs were performed with a 26-gauge or smaller needle, which is much smaller than those utilized in most acute care environments. However, the reduction in PDPH remained consistent when analyzed among only larger needles. Nonetheless, it is possible that a greater reduction in PDPH may have been seen with the use of the larger atraumatic needles typically used in the ED setting. Ease of use for specific needles was not well described. Additionally, pediatric patients comprised only 3.4% of the total. No LPs were performed by acute care physicians, some were performed with the assistance of advanced imaging, and most were interventional rather than diagnostic. It is therefore unclear how these findings may translate to acute care. Finally, the review did not assess the potential costs of atraumatic versus conventional needles. While atraumatic needles are more expensive, a 2012 study found that the use of atraumatic needles was associated with significant overall savings to the healthcare system.5

Based on the above data, atraumatic needles were associated with a reduced rate of PDPH with no difference in failure rates. We have therefore assigned a color recommendation of Green (Benefits outweigh harms) to this intervention overall, with recognition that randomized trials from acute care environments are needed.

The original manuscript was published in Academic Emergency Medicine as part of the partnership between TheNNT.com and AEM.

Author: Michael Gottlieb, MD; Brit Long, MD
Supervising Editor: Shahriar Zehtabchi, MD

Published/Updated: July 1, 2020

  1. The Title Bar

    The title bar is color-coded with our overall recommendation.

    • Green: Benefits outweigh risks.
    • Yellow: Unclear risk/benefit profile.
    • Red: Benefits do not outweigh risks.
    • Black: Obvious harms, no clear benefits.
  2. Tip content...