Canule

Canule is a term that is sometimes used as an alternate spelling of cannula, a slender, flexible tube inserted into the body to access a lumen or cavity for delivery or withdrawal of fluids, gases, or instruments. In medical and surgical contexts, canules (cannulas) are essential tools for procedures ranging from routine IV therapy to diagnostic sampling. The spelling can vary by language and discipline, and canule may appear in older or regional sources as a variant of cannula.

Cannulas come in many forms and sizes. An intravenous cannula provides venous access for medications and fluids, typically inserted after skin preparation. Other types include arterial cannulas for monitoring blood pressure or drawing arterial samples, and chest drain cannulas for removing air or fluid from the pleural space. Nasal cannulas deliver supplemental oxygen through the nostrils, while arthroscopic cannulas are used to create ports during joint surgery. Cannulas are usually made of flexible plastic or stainless steel and are sized by diameter, often described in gauges.

Insertion and care involve aseptic technique and proper sizing to minimize complications. The device may be introduced with a needle or via an introducer system, and secured to prevent movement. Potential risks include infection, infiltration or extravasation of fluids, thrombosis, and embolism. Removal is typically straightforward once access is no longer required. Proper handling, monitoring, and adherence to device-specific guidelines are essential to ensure safety and effectiveness. See also cannula, nasal cannula, intravenous therapy, and arthroscopy cannula.