Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
An epidural needle is usually a Tuohy needle: a hollow, stainless steel needle with a slightly curved tip, a transparent hub, optional wings and centimetre markings along the shaft, supplied with an inner stylet whose hub is colour-coded by needle diameter. This page shows how to recognise each part and how one manufacturer’s range maps gauge to colour, diameter and length. It is written for clinic staff, buyers and students who need to identify the product class, not to teach a procedure.
What an epidural needle looks like
What does an epidural needle look like?
The common epidural needle is the Tuohy needle, described as a hollow hypodermic needle that is very slightly curved at the end. The curved tip is what separates it from a straight hypodermic needle (see what a hypodermic needle is). Wikipedia’s account describes the Tuohy needle as popularised by the US anaesthesiologist Edward Boyce Tuohy in 1945, with a curved tip designed to make a catheter passing through the needle exit sideways at a 45 degree angle.
Vygon’s Tuohy needle is used for epidural anaesthesia. Vygon states it is usually used to introduce an epidural catheter for repeated dosing or postoperative analgesia, and can also be used to give a single dose.
What does the epidural needle look like, and what does an epidural needle look like compared with other needles?
Beyond the curved tip, the visible differences are the markings, the wings and the stylet. A standard injection needle has none of these. The next section goes through the parts one by one.
Parts you can see
- Curved distal tip and bevel. Vygon states that the heel of the bevel is smoothed to reduce the risk of cutting the epidural catheter. The stylet hub carries a lug that shows the bevel orientation.
- Centimetric graduations. Markings along the shaft, listed by Vygon as a feature of its Tuohy needle. A listed FDA device record (Hakko) also describes the product as having calibrations.
- Transparent hub. Vygon describes a transparent hub that lets fluid reflux, blood or cerebrospinal fluid, be seen.
- Removable wings. Vygon lists removable wings. The Hakko record describes a plastic hub with wings.
- Stylet. An inner stylet sits in the needle. Vygon’s is stainless steel (code 184.881 has a plastic stylet), and its hub colour matches the needle diameter.
Gauges, colours and lengths (one manufacturer’s range)
The table below is taken from Vygon’s Standard LUER range Tuohy needle page. It is one manufacturer’s range; other makers can use different colours and lengths, so do not treat the colours as universal.
| Gauge | Stylet hub colour | Outer diameter (mm) | Inner diameter (mm) | Lengths listed (mm) |
|---|---|---|---|---|
| 16G | Blue | 1.65 | 1.35 | 80, 90 |
| 17G | White | 1.5 | 1.2 | 80, 90, 120 |
| 18G | Pink | 1.32 (1.30 on the 80 mm models) | 1.12 (1.07 on the 80 mm models) | 80, 90, 120, 153 |
| 19G | Cream | 1.08 | 0.8 | 90 |
For a second reference point, an FDA AccessGUDID record for a Hakko Tuohy Epidural Needle describes a 17G needle of 100 mm (4 inches) with a plastic hub, wings and calibrations. It is single-use, supplied sterile, and carries FDA product code BSP (needle, conduction, anesthetic, with or without introducer).
Variants
- Back-eye needle. Vygon code 184.882 (18G, 80 mm) has an opening in the curved distal end. Vygon notes this is useful for combined spinal-epidural technique.
- Extra-long needles. Vygon states that extra-long needles are available; no lengths are listed here.
- Plastic versus steel stylet. Vygon’s 184.881 uses a plastic stylet; the others use stainless steel.
- Plastic versus other hub materials. The Hakko record lists a plastic hub; check the product record for any specific model.
Connectors: why the hub end matters
Epidural and other neuraxial devices have been moving to a dedicated small-bore connector standard, ISO 80369-6, published on 15 March 2016 and designated NRFit. The American Society of Regional Anesthesia and Pain Medicine (ASRA) explains that it looks like a Luer connector but is 20 percent smaller, and that it is designed to reduce cross-connections with Luer devices. In ASRA’s July 2018 article, there was no formal timeline for transition from Luer to NRFit, adaptors would not be manufactured, some manufacturers might use yellow (optional), and California mandated use from 1 January 2017. That is the position as of 2018; check current status with the manufacturer. For related supply context see infusion supplies and pump selection.
Who uses it
Epidural needles are used by anaesthesia and pain-management clinicians, and the supplies are stocked by the clinics and hospitals that perform epidural procedures. A clinic-supply view of the wider category is in the pain-management clinic supply checklist, and catheter securement is covered in the StatLock guide.
Safe handling basics
The Hakko FDA record lists the device as single-use and supplied sterile, and it is a prescription device. Follow the manufacturer’s instructions for use for the specific model. For how device problems are tracked, see medical device reporting.
Common mistakes when identifying one
- Assuming hub colours are universal. The colour code above belongs to Vygon’s range; confirm gauge from the label.
- Judging by a single dimension. Gauge, outer diameter and length are separate; the same gauge appears in several lengths.
- Overlooking the back-eye variant. A Tuohy-type needle with an opening in the curved end (Vygon 184.882) is made for combined spinal-epidural use, so it can look different from the plain version.
- Assuming Luer and NRFit parts are interchangeable. ASRA says the NRFit design is meant to reduce cross-connections with Luer connectors.
FAQ
What does an epidural needle look like?
A hollow stainless steel needle with a slightly curved tip, centimetre markings on the shaft, a transparent hub, optional wings, and an inner stylet with a colour-coded hub.
What does the epidural needle look like at the tip?
The tip is slightly curved, which makes a catheter passing through it exit sideways at about 45 degrees; Vygon adds that the bevel heel is smoothed to reduce the risk of cutting the catheter.
What does epidural needle look like in terms of size?
In Vygon’s range, 16G to 19G, with outer diameters from 1.08 to 1.65 mm and lengths of 80 to 153 mm, as listed in the table.
What does a epidural needle look like when it is a combined spinal-epidural type?
It has an opening (back-eye) in the curved distal end, as in Vygon code 184.882 (18G, 80 mm).
Sources
Each source was checked on 2026-10-30.
- Vygon, Needles: Tuohy, Standard LUER range, https://be.vygon.com/en/products/nervous/standard-luer-range/epidural-anaesthesia-needles-and-catheters/needles-tuohy (checked 2026-10-30).
- FDA AccessGUDID, Hakko Tuohy Epidural Needle, https://accessgudid.nlm.nih.gov/devices/04526737170763 (checked 2026-10-30).
- ASRA, What is ISO 80369-6:2016? 27 July 2018, https://asra.com/news-publications/asra-newsletter/newsletter-item/asra-news/2018/07/27/what-is-iso-80369-6-2016- (checked 2026-10-30).
- Tuohy needle, https://en.wikipedia.org/wiki/Tuohy_needle (checked 2026-10-30).
