A catheter and a cannula are both thin tubes used in medical procedures, but they serve different purposes and are inserted into different parts of the body.
Key Differences: Catheter vs. Cannula
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Catheter: A catheter is a flexible tube inserted into a body cavity, primarily to drain fluids. The most common example is a urinary catheter, which drains urine from the bladder. Other types drain fluids from other parts of the body.
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Cannula: A cannula is a thin, hollow tube inserted into a blood vessel (vein or artery). Its purpose is to administer fluids or medications directly into the bloodstream, or to draw blood samples for testing. Intravenous (IV) lines use cannulas.
Here's a table summarizing the key differences:
| Feature | Catheter | Cannula |
|---|---|---|
| Purpose | Drain fluids from body cavities | Administer fluids/medications, draw blood |
| Insertion Site | Body cavity (e.g., bladder) | Blood vessel (vein or artery) |
| Common Use | Urinary drainage, draining other fluids | IV fluids, blood draws, medication delivery |
Examples:
- Catheter Example: A Foley catheter is inserted into the bladder to drain urine.
- Cannula Example: An IV cannula is inserted into a vein in the arm to deliver fluids or medications.
The provided reference states: "Catheters are flexible tubes that are inserted into a body cavity, such as the bladder, to drain urine. Cannula, on the other hand, are thin, hollow tubes that are inserted into a vein or artery to allow for the delivery of fluids or medication, or to draw blood for diagnostic purposes." This accurately reflects the core differences outlined above.
