Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
A tracheostomy inner cannula is the removable inner tube that sits inside the outer cannula of a double-cannula tracheostomy tube. Clinic staff, materials managers and students searching for it usually need to know which inner cannula types exist and how an item is matched to a tube. This page answers that using one manufacturer family, Shiley, as the worked example; other brands name and number their parts differently.
What a tracheostomy inner cannula is
An inner cannula is a tube that fits within the outer cannula of a tracheostomy tube. On the Shiley range it is sold as a separate item with its own item number. Manufacturer listings describe two roles: a disposable inner cannula intended for a single use, and a spare inner cannula intended for temporary use while the inner cannula of a reusable tube is being cleaned or removed. For the rest of the tube (outer cannula, flange, cuff, pilot balloon), see what a tracheostomy tube is.
Who uses it: clinical staff and caregivers who work with double-cannula tubes, and the buyers and supply teams who stock the matching parts.
How a Shiley inner cannula is built
Medtronic’s product page for the Shiley disposable inner cannula states that it has an integral 15 mm snap-lock connector, is supplied sterile in individual packaging, is for single use only, and is not made with natural rubber latex. The fenestrated version has a snap-lock, green colour-coded connector. The Shiley spare inner cannula page states that it is sterile, individually packaged and latex-free.
Types of Shiley inner cannula
| Type | Stated purpose | Key difference | Item-number pattern |
|---|---|---|---|
| Disposable inner cannula | Single-use inner cannula for the listed Shiley tubes | Supplied sterile, for single use only; 15 mm snap-lock connector | [size]DIC, for example 6DIC |
| Disposable inner cannula, fenestrated | Single-use inner cannula for the listed fenestrated tubes | Green colour-coded connector; listed only with fenestrated tubes (DFEN, DCFN) | [size]DICFEN |
| Spare inner cannula | Temporary use during cleaning or removal of the inner cannula of Shiley reusable tracheostomy tubes | Listed for the LPC, FEN, CFS and CFN tubes; the page does not describe it as single-use | [size]SIC |
Sources: Medtronic Shiley disposable inner cannula page and Shiley spare inner cannula page, both checked 2026-10-30.
Sizes and item numbers
Medtronic lists each inner cannula in sizes 4.0, 6.0, 8.0 and 10.0, ten units per box. The size column on the manufacturer page carries no stated unit, so it is shown here as listed. The compatibility lists are the useful part: each item number is listed for specific tube codes only.
| Item number | Size (as listed) | Listed for use with | Units per box |
|---|---|---|---|
| 4DIC | 4.0 | 4DCT, 4DCFS, 4DFEN, 4DCFN | 10 |
| 6DIC | 6.0 | 6DCT, 6DCFS, 6DFEN, 6DCFN | 10 |
| 8DIC | 8.0 | 8DCT, 8DCFS, 8DFEN, 8DCFN | 10 |
| 10DIC | 10.0 | 10DCT, 10DCFS, 10DFEN, 10DCFN | 10 |
| 4DICFEN | 4.0 | 4DFEN, 4DCFN | 10 |
| 6DICFEN | 6.0 | 6DFEN, 6DCFN | 10 |
| 8DICFEN | 8.0 | 8DFEN, 8DCFN | 10 |
| 10DICFEN | 10.0 | 10DFEN, 10DCFN | 10 |
| 4SIC | 4.0 | 4LPC, 4FEN, 4CFS, 4CFN | 10 |
| 6SIC | 6.0 | 6LPC, 6FEN, 6CFS, 6CFN | 10 |
| 8SIC | 8.0 | 8LPC, 8FEN, 8CFS, 8CFN | 10 |
| 10SIC | 10.0 | 10LPC, 10FEN, 10CFS, 10CFN | 10 |
Source: Medtronic Shiley product pages, checked 2026-10-30. For outer tube dimensions, see tracheostomy tube sizes.
Matching an inner cannula to a tube
The manufacturer lists show that the disposable and spare inner cannulas are each listed for named tube codes, not for a size alone. For example, the disposable 6DIC is listed for 6DCT, 6DCFS, 6DFEN and 6DCFN, while the spare 6SIC is listed for 6LPC, 6FEN, 6CFS and 6CFN. The fenestrated disposable inner cannulas are listed only for fenestrated tubes. So the tube model and the item number both need to be read from the product listing; the size number by itself does not identify the part.
Labelling and handling basics
Medtronic labels the Shiley disposable inner cannula sterile and for single use only. Its page for the spare inner cannula describes temporary use while a reusable tube’s inner cannula is cleaned or removed. Instructions for use are supplied with each specific tube.
Common matching points
- The size number alone does not identify a part: the manufacturer lists name specific compatible tubes.
- The disposable (DIC) and spare (SIC) families have different stated purposes and different listed tube codes.
- The DICFEN items are listed only for fenestrated tubes (DFEN, DCFN).
What a tracheostomy obturator is
A tracheostomy obturator is a separate insert supplied with a tracheostomy tube. It is not the inner cannula: the inner cannula sits inside the outer cannula, while the obturator is its own part. A teaching activity on tracheostomy basics published in the Journal of Education and Teaching in Emergency Medicine lists the obturator, the inner cannula, the outer cannula and the flange as separate components of a tracheostomy tube, and a 2026 paper in Frontiers in Pediatrics lists an obturator among the items that a child’s bedside emergency kit should include, alongside same-size and smaller-size tubes. A 2025 survey of 520 healthcare providers in the International Archives of Otorhinolaryngology, which uses the paired term “introducer/obturator”, found that 30.5% did not know its function, which is one reason the part is worth identifying by name. The tracheostomy tube guide defines it as a smooth, rounded insert supplied with the tube.
| Part | What it is | Where it sits |
|---|---|---|
| Obturator | A separate insert supplied with the tube; also called an introducer in some papers | Not a permanent part of the assembled tube |
| Inner cannula | The removable inner tube; disposable and spare versions exist (see above) | Inside the outer cannula |
| Outer cannula | The main tube that stays in the airway opening | Holds the inner cannula |
The US device regulation for these products, 21 CFR 868.5800, identifies a tracheostomy tube and tube cuff as a device placed into a surgical opening of the trachea to facilitate ventilation, and classifies it as Class II. The regulation text does not name the obturator separately, so what a given obturator looks like and how it is supplied is set by the manufacturer’s labelling for that tube. Instructions for use come with each tube.
FAQ
What is an obturator in tracheostomy?
An obturator is a separate insert supplied with a tracheostomy tube. It is a different part from the inner cannula. The tracheostomy tube guide describes it among the tube’s parts.
Is a tracheostomy inner cannula single-use?
It depends on the product. Medtronic labels its Shiley disposable inner cannula sterile and for single use only; its page for the Shiley spare inner cannula describes temporary use during cleaning or removal of a reusable tube’s inner cannula and does not describe it as single-use.
Do inner cannulas contain latex?
Medtronic states the Shiley disposable inner cannula is not made with natural rubber latex and the spare inner cannula is latex-free. Other brands need their own labelling checked.
Is a tracheostomy obturator the same as an inner cannula?
No. They are listed as separate components of a tracheostomy tube in the teaching literature cited above. The inner cannula is a removable tube that fits inside the outer cannula and is sold as its own item; the obturator is a separate insert supplied with the tube.
Related guides
See also the Passy Muir valve and the tracheostomy collar guides.
Sources
- Medtronic, Shiley disposable inner cannula product page, https://www.medtronic.com/en-us/healthcare-professionals/products/respiratory/tracheostomy/inner-cannulas/shiley-disposable-inner-cannula.html (checked 2026-10-30)
- Medtronic, Shiley spare inner cannula product page, https://www.medtronic.com/en-us/healthcare-professionals/products/respiratory/tracheostomy/inner-cannulas/shiley-spare-inner-cannula.html (checked 2026-10-30)
- Troubleshooting the Trach: Emergent Tracheostomy and Laryngectomies, Journal of Education and Teaching in Emergency Medicine, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC12594468/ (checked 2026-10-31)
- Frontiers in Pediatrics, From PICU to home: a longitudinal airway safety framework for children with tracheostomies, 2026, https://pmc.ncbi.nlm.nih.gov/articles/PMC13530889/ (checked 2026-10-31)
- International Archives of Otorhinolaryngology, Assessment of Healthcare Providers’ Knowledge on the Management of Pediatric Tracheostomy Emergencies, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC12037218/ (checked 2026-10-31)
- eCFR, 21 CFR 868.5800 Tracheostomy tube and tube cuff, https://www.ecfr.gov/current/title-21/section-868.5800 (checked 2026-10-31)
