Suction Catheter Sizes & Types: French Chart, Yankauer and How to Choose
May 31, 2026 · 11 min read · Edaochi Medical
The suction catheter clears secretions from the airway in the ICU, anaesthesia, the ER and home care — and choosing the wrong size is one of the most common errors in nursing: a catheter too small won't clear thick secretions, while one too large causes deep hypoxia, tracheal mucosa trauma and even bronchospasm. "Suction catheter" also covers more than one product: the flexible tracheal catheter, the rigid Yankauer for the mouth, the closed-system catheter for ventilated patients, and the all-in-one kit. This is a selection and buying guide: it explains the French sizing scale with a chart and colour code, the half rule for matching the endotracheal tube, sizes by patient age, the tip types, and what to check before buying wholesale. It's part of our guide to the types of catheters.
The French (Fr) scale for suction catheters
Suction catheters are sized on the French scale (Fr or CH), the same universal scale used for catheters and tubes. The rule: 1 French = 0.33 mm of outer diameter, so to convert a diameter in mm to French you multiply by 3 (a 4 mm catheter = F12). The higher the number, the thicker the catheter.
Most manufacturers colour-code the size on the connector, an international standard that lets nursing pick the right size at a glance:
| Size (Fr) | Colour | Typical patient |
|---|---|---|
| F6 – F8 | Light green / orange | Neonate / infant |
| F10 | Black | Infant / small child |
| F12 | White | Child / small adult |
| F14 | Green | Adult, standard |
| F16 | Orange / red | Adult, thick secretions |
| F18 | Red | High-volume oropharyngeal suction |
What the French number does NOT tell you is the inner lumen diameter, which depends on wall thickness: a thin-wall PVC F14 has a larger lumen than a silicone F14. For high-flow suction of thick secretions, a thin-wall design matters as much as the French number.
The half rule: sizing to the endotracheal tube
In an intubated or tracheostomy patient, the size is driven by the tube, not just the patient. The most-used guideline is the half rule: the outer diameter of the suction catheter should not exceed half the inner diameter of the endotracheal tube (ETT).
Practical formula: suction catheter size (Fr) ≤ ETT inner diameter (mm) × 2.
- Example: an ETT with 8.0 mm ID → maximum F16 catheter.
- Some more conservative protocols use ×1.5 instead of ×2, giving a slightly smaller catheter and less hypoxia risk, at the cost of slightly less effective suction with very thick secretions.
Why it matters: a catheter too large for the tube occludes airflow and the vacuum draws gas from the lungs, causing rapid desaturation and atelectasis. The suction pass should also stay under 10–15 seconds, and in critically ill patients with high FiO₂, pre-oxygenate at 100% for 30–60 seconds before suctioning.
Sizes by patient: neonate, paediatric and adult
For non-intubated suctioning (nasotracheal or oropharyngeal), size is chosen by age and body size. A summary:
| Patient | Size (Fr) | Note |
|---|---|---|
| Premature neonate | F4 – F6 | Thin-wall; vacuum only 40–60 mmHg |
| Term neonate | F6 – F8 | Vacuum 60–80 mmHg |
| Infant (0–12 mo) | F6 – F8 | — |
| Child (1–4 yr) | F8 – F10 | — |
| Child (5–12 yr) | F10 – F12 | — |
| Adult | F12 – F16 | F12 clear secretions; F14–F16 thick |
| Special / surgical | F18 – F20 | High-volume or open-field only |
Key safety point: the neonatal airway is so small that an adult vacuum pressure can cause immediate alveolar collapse — vacuum must be set far lower in neonates than adults. Always use water-soluble lubricant for nasotracheal passes to reduce mucosal trauma.
Tip types and features: flexible, Yankauer and closed-system
"Suction catheter" is a family, not one product. The main variants:
- Flexible tracheal catheter: the standard soft PVC catheter for the airway and ET tube. Look for an atraumatic tip and side holes so it doesn't grab and injure the mucosa.
- Suction control port: a thumb-port valve so the operator applies suction only on withdrawal, not on insertion — reduces trauma and hypoxia.
- Yankauer: a rigid tonsil-tip device for oropharyngeal (mouth) suction — clearing vomit, blood or large-volume secretions in the ER and surgery. Distinct from the flexible tracheal catheter.
- Closed-system (in-line) catheter: stays connected within the ventilator circuit so the patient isn't disconnected to suction — lowers infection risk and desaturation in ICU; changed every 24–72 h.
- All-in-one suction kit: catheter + sterile glove + connector in one pack, for fast aseptic suctioning in the ER.
Material is usually clear PVC so the aspirate colour is visible; side holes and a smooth moulded tip are the marks of a quality catheter.
What to check before buying wholesale (ICU, ER and distributors)
For a hospital restocking or a distributor, the points that separate a reliable suction catheter from one that generates complaints:
- Full size range with colour code: F4 to F20 with a standard colour-coded connector so nursing identifies the size instantly.
- Thin-wall lumen: a larger inner lumen for the same French size means more effective suction of thick secretions.
- Atraumatic moulded tip + side holes: to avoid mucosal injury and the catheter grabbing the airway wall.
- Suction control port: for controlled suction on withdrawal.
- Clear PVC: to see the aspirate; latex-free.
- Yankauer and closed-system lines: availability of the rigid Yankauer and the in-line closed-system catheter, not just the flexible one.
- Sterilisation and packaging: sterile (EO), individual pack; single use.
- MOQ, samples and private label (OEM): accessible minimum order, samples, and private-label packaging for distributors.
Edaochi Medical manufactures disposable suction catheters from F4 to F20 in clear PVC with an atraumatic tip, side holes and thumb suction-control port, colour-coded by size; plus the all-in-one suction kit (catheter + glove + connector). Low minimum order, samples for evaluation, quality documentation for registration and a private-label (OEM) option. Tell us the sizes and volumes you need and we'll build the box-price and MOQ quote on WhatsApp in under 24 hours.
Frequently Asked Questions
What size suction catheter is used for an adult?
For an adult, F12–F16 covers most cases: F12 for clear, moderate secretions and F14–F16 for thick secretions or when more effective suction is needed. F18–F20 is reserved for high-volume oropharyngeal suction or open surgical fields. In an intubated patient, apply the half rule (catheter Fr ≤ ETT inner diameter in mm × 2).
How do you choose a suction catheter size for an intubated patient?
Use the half rule: the suction catheter's outer diameter should not exceed half the inner diameter of the endotracheal tube. In practice, catheter size in Fr ≤ ETT inner diameter in mm × 2. For example, an 8.0 mm ID tube allows up to F16. A catheter too large occludes the tube and the vacuum pulls gas from the lungs, causing desaturation.
What is the difference between a Yankauer and a flexible suction catheter?
The Yankauer is a rigid, tonsil-tip device for oropharyngeal (mouth) suction — clearing vomit, blood or large-volume secretions in the ER and surgery. The flexible suction catheter is a soft PVC tube for the airway and endotracheal tube, with an atraumatic tip and side holes. They are different products for different jobs and most facilities stock both.
What size suction catheter is used for a neonate?
Premature neonates use F4–F6 and term neonates F6–F8, always thin-wall to maximise the lumen at minimum diameter. Critically, the vacuum pressure must be much lower than in adults — about 40–60 mmHg for premature and 60–80 mmHg for term neonates — because an adult vacuum can cause immediate alveolar collapse in the tiny neonatal airway.
What is a closed-system (in-line) suction catheter?
A closed-system or in-line suction catheter stays connected within the ventilator circuit, so the patient is not disconnected from the ventilator to be suctioned. This lowers the risk of ventilator-associated infection and desaturation in ICU patients. It is typically changed every 24–72 hours, versus single-use for the open flexible catheter.
Does Edaochi supply the full size range and private label (OEM)?
Yes. Edaochi Medical manufactures disposable suction catheters from F4 to F20 in clear PVC with an atraumatic tip, side holes and a thumb suction-control port, colour-coded by size, plus an all-in-one suction kit. We offer a low minimum order, samples for evaluation, quality documentation (ISO 13485) for registration and private-label (OEM) packaging for distributors. A box-price and MOQ quote is delivered on WhatsApp in under 24 hours.
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