Several studies have tested the value of new needles during lumbar puncture, so-called “atraumatic” needles. A pooled analysis of these studies, called a “meta-analysis”, clearly shows the benefit over conventional needles.
During a lumbar puncture, the use of “atraumatic” needles rather than conventional needles makes it possible to reduce the frequency of the so dreaded complications of this procedure: headaches with nausea, prolonged vomiting …
These results come from a combined analysis of all good quality studies, a meta-analysis, conducted by an international team of researchers and published in the Lancet.
Two different types of needles
In practice, needles are classified according to the appearance of their point. Conventional needles are the most frequently used in clinical practice and have an oblique, bevelled point, designed to penetrate the envelope of the spinal cord, the meninges, and in particular the thickest of them: the dura. It’s a pretty big needle with some sort of mandrel inside. This is removed once the needle is in place in order to perform an injection of products or the collection of cerebrospinal fluid (or CSF).
Atraumatic needles have a lateral orifice for injection or collection, they were developed 70 years ago but remain little used in clinical practice.
Studies that have been done on cadavers (post-mortem studies) show that the bevel of conventional needles cut tissue causing irregular lacerations that can increase the risk of CSF leakage and post-lumbar puncture syndrome.
In contrast, the atraumatic needles separate and spread the fibers of the meninge, resulting in a smaller opening that closes better. In vitro studies also show that the rate of CSF leakage due to dural perforations decreases with atraumatic needles compared to conventional ones.
Fewer side effects with atraumatic needles
The meta-analysis compared the results after a lumbar puncture performed either with a conventional needle or with an atraumatic needle. To do this, the researchers analyzed data from 110 trials carried out in 29 different countries and involving 31,412 participants.
In practice, the incidence of headaches (“headaches”) occurring after a lumbar puncture is significantly reduced from 11% in the group of conventional needles to 2% in the atraumatic needle group, which corresponds to a reduction of 60% .
However, the “post-lumbar puncture” headache is the most frequent complication after this invasive procedure, occurring in 35% of cases. It is believed to be due to a prolonged leakage of cerebrospinal fluid created by the needle during the puncture. Many factors are involved: the needle, its tip, the patient’s position, bed rest, the clinician’s experience.
Atraumatic versus conventional lumbar puncture needles: a systematic review and meta-analysis – in this week’s issue https://t.co/nbxw1IpJjY
– The Lancet (@TheLancet) March 26, 2018
Furthermore, the use of atraumatic needles was also associated with a reduction in the use of pain relievers, nerve root irritation and hearing impairment. Finally, the performance characteristics including the failure rate, the first attempt success rate and the average number of attempts were similar in the two groups, which means that both types of needles are equally practical. ‘one than the other.
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