A Tuohy (/tOO-ee/) needle is a hollow
hypodermic needle
A hypodermic needle (from Greek ὑπο- (''hypo-'' = under), and δέρμα (''derma'' = skin)), one of a category of medical tools which enter the skin, called sharps, is a very thin, hollow tube with one sharp tip. It is commonly used w ...
, very slightly curved at the end, suitable for inserting
epidural
Epidural administration (from Ancient Greek ἐπί, , upon" + ''dura mater'') is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians an ...
catheters.
Epidural needle
Literally, an
epidural
Epidural administration (from Ancient Greek ἐπί, , upon" + ''dura mater'') is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians an ...
needle is simply a needle that is placed into the epidural space. To provide continuous epidural analgesia or anesthesia, a small hollow catheter may be threaded through the epidural needle into the epidural space, and left there while the needle is removed. There are multiple types of epidural needles as well as catheters, but in modern practice in developed nations, disposable materials are used to ensure sterility.
Epidural needles are designed with a curved tip to help prevent puncture of the
dural membrane. But following accidental dural puncture, headache occurs in up to 85% of patients causing significant perioperative morbidity.
However, in case of inadvertent dural perforation, the incidence of headache can be lowered by identifying the epidural space with the needle bevel oriented parallel to the longitudinal dural fibers which limits the size of the subsequent
dural tear.
Types
Types of epidural needles include:
* The Crawford Needle
* The Tuohy Needle
* The Hustead Needle
* The Weiss Needle
* The Sprotte Spezial Needle
* Other Epidural Needles : Other less popular types are the Wagner needle (1957), the Cheng needle(1958), the Crawley needle (1968), the Foldes needle (1973), and the Bell needle (1975)—all variants of the Huber design with a blunted tip of varying sharpness.
* Variants like the Brace needle, a Crawford variant; the Lutz epidural needle (1963), with a pencil-point design for single-shot epidural use; the Scott needle (1985), a Tuohy needle with a Luer lock hub; and the Eldor needle (1993), designed for use with combined spinal epidural anesthesia.
History
Though Ralph L. Huber (1915–2006), a Seattle dentist was the inventor of this needle in 1940, it is known in the name of Edward Boyce Tuohy (1908–1959), a 20th-century U.S anesthesiologist who first popularized it in 1945.
References
Further reading
*
* {{cite journal, last=Frölich, first=MA, author2=Caton, D , title=Pioneers in epidural needle design., journal=Anesthesia and Analgesia, date=July 2001, volume=93, issue=1, pages=215–20, pmid=11429369, url=http://www.anesthesia-analgesia.org/content/93/1/215.full, doi=10.1097/00000539-200107000-00043
Medical equipment
Neurology procedures