A Shiley catheter is a brand of tracheostomy tube, a curved plastic device placed through a small surgical opening in the front of the neck directly into the windpipe. Despite the name “catheter,” it is not a urinary or IV catheter. Shiley is one of the most widely used tracheostomy brands in hospitals, and the name has become nearly synonymous with tracheostomy tubes in clinical settings. These tubes keep the airway open for people who need long-term breathing support, help with secretion management, or cannot safely breathe through their mouth and nose.
Why a Shiley Tube Is Used
A Shiley tracheostomy tube serves as a direct pathway for air to reach the lungs, bypassing the upper airway entirely. It is placed when a patient needs prolonged mechanical ventilation, has a blocked or swollen upper airway, or cannot protect their airway from fluids and secretions entering the lungs. Common situations include severe head or neck injuries, neurological conditions that weaken the muscles of breathing and swallowing, and recovery from major throat or neck surgery.
Parts of a Shiley Tube
A Shiley tube is made up of several components that work together, and understanding them helps if you or a family member will be managing one at home.
The outer cannula is the main body of the tube. It sits in the stoma (the opening in the neck) and stays in place between scheduled tube changes. Attached to it is the flange, a flat or flexible plate that rests against the skin of the neck. The flange has holes on each side where cloth ties or a Velcro strap secure the tube so it doesn’t shift or fall out. Many Shiley models feature a soft, swivel-style flange that adjusts to the angle of the neck for comfort.
The inner cannula slides inside the outer cannula and can be removed for cleaning or replacement without disturbing the main tube. This is one of the most practical features of the Shiley design. Mucus and secretions build up inside the tube over time, and being able to swap out just the inner cannula keeps the airway clear. Disposable versions snap into place with a connector and are thrown away after a single use. Reusable versions twist and lock in, and they are translucent so caregivers can visually check for blockages.
The obturator is a smooth, rounded plug that fits inside the tube only during insertion. Its job is to guide the tube into the stoma without catching on tissue. Once the tube is in place, the obturator is removed and replaced by the inner cannula. Obturators are also designed with a small hole at the tip to accept a guidewire, which can help during reinsertion if the tube accidentally comes out. For this reason, the obturator should always be kept at the bedside or nearby.
On cuffed models, a small pilot balloon sits outside the neck attached to a thin line running to an inflatable cuff at the tip of the tube inside the windpipe. Squeezing the pilot balloon tells caregivers whether the cuff is inflated or deflated, and it is the access point for adding or removing air from the cuff.
Cuffed vs. Uncuffed Tubes
Shiley tubes come in both cuffed and uncuffed versions, and the choice depends on the patient’s breathing and swallowing ability.
A cuffed tube has a small inflatable balloon near its tip that, when filled with air, creates a seal against the walls of the windpipe. This seal serves two purposes: it allows a ventilator to deliver pressurized air without leaking, and it reduces the risk of saliva or food sliding past the tube into the lungs. Cuff pressure needs to stay within a safe range, typically 25 to 34 cmH2O, to avoid damaging the delicate lining of the windpipe. Caregivers check this regularly with a small pressure gauge.
An uncuffed tube has no balloon and leaves a gap between the tube and the windpipe wall. This type is appropriate for patients who can protect their own airway, have a strong cough reflex, and manage their own secretions. Without a cuff, air can flow upward past the tube and through the vocal cords, which makes speech easier. It also eliminates the risk of pressure injury to the windpipe wall that an inflated cuff can cause over time.
Fenestrated Tubes and Speech
Some Shiley models are fenestrated, meaning they have one or more small holes cut into the curve of the outer cannula. When the inner cannula is removed or replaced with a cap, air flows through these openings, up through the vocal cords, and out the mouth and nose. This allows the patient to speak and is a significant quality-of-life feature. Fenestrated tubes also improve chest expansion and reduce the risk of small areas of lung collapse that can develop when airflow patterns change after a tracheostomy.
Fenestrated tubes are commonly used as a bridge toward decannulation, the process of removing the tracheostomy tube permanently. As patients regain the ability to breathe and swallow on their own, the fenestrated tube lets clinicians test upper airway breathing while the tube remains in place as a safety net. Correct sizing matters here: if the tube is too large for the windpipe, air can leak through the fenestrations in the wrong direction, reducing the benefit.
Common Sizes
Shiley tubes are labeled by size number, and each size corresponds to specific inner and outer diameters measured in millimeters. The three most common adult sizes are:
- Size 4: 5.0 mm inner diameter, 9.4 mm outer diameter
- Size 6: 6.4 mm inner diameter, 10.8 mm outer diameter
- Size 8: 7.6 mm inner diameter, 12.2 mm outer diameter
The right size depends on the patient’s anatomy. A tube that is too large can cause pressure damage, while one that is too small may not seal properly with the cuff or could allow too much air leakage. Extended-length versions are available for patients with thicker necks or unusual anatomy where a standard-length tube does not reach far enough into the windpipe. Modified flange angles and custom cuff configurations can also be ordered.
Inner Cannula Care and Tube Replacement
Keeping the inner cannula clean is the single most important daily maintenance task. Mucus, dried secretions, and biofilm can partially or fully block the tube, making breathing difficult or dangerous. In hospital settings, disposable inner cannulas are typically changed twice a day to limit germ exposure. At home, once a day is the standard recommendation, though patients who produce heavy secretions due to allergies, colds, or weather changes may need to rinse and reuse the inner cannula before its scheduled change. Even with rinsing, a disposable inner cannula should be discarded after 24 hours of use.
The entire Shiley tracheostomy tube is designed for single use. When it is time for a routine tube change (often weekly, though schedules vary), the old tube is removed and a new one is placed. The old tube should not be boiled, re-sterilized, or reused. During tube changes, the obturator is inserted into the new tube to smooth the tip, the tube is guided into the stoma, the obturator is removed, and the inner cannula is locked into place. The whole process takes seconds for an experienced caregiver, though it can feel intimidating the first few times for family members learning at home.
Living With a Shiley Tube
For patients who go home with a Shiley tube, daily life involves a few consistent routines. Inner cannula changes, stoma cleaning, and checking that the ties or strap holding the flange are snug but not too tight become part of the rhythm. Humidity matters: because air no longer passes through the nose and mouth where it would normally be warmed and moistened, dry air can thicken secretions and increase the risk of blockages. Many patients use a heat and moisture exchanger, a small filter that attaches to the tube opening, or a bedside humidifier.
The obturator and a spare tube of the same size should always be within reach. If the tube is accidentally dislodged, having these supplies immediately available allows for quick reinsertion before the stoma begins to narrow, which can happen surprisingly fast. Caregivers are typically trained on reinsertion before the patient is discharged from the hospital.