A common medical process found in almost every medical and health institution or clinics that would be cannulation. It’s critical requirement in cases where patients are not able to either remove or receive bodily fluids. Such patients are assisted using equipment called cannula – a duct occupied with a trocar needle at one end. The functions could involve access to blood stream, administration of fluids, medications, chemotherapy, parenteral nutrition, blood products etc.
Cannulation is the process of inserting a tube (cannula) into a passage, duct or cavity to supply or withdraw material or data. In medical dictionary, cannulation is a process used to deliver or remove body fluids under various medical conditions, like withdrawing blood for sampling. Effective needle length is extended by half the length of the original needle in cannula by surrounding either the inner or outer surfaces of a trocar needle. The trocar helps puncturing of tissues on a defined space to gain access to a body part.
Types of Cannulation
There are different types of cannulation practiced in medical processes. Following are the most common:
Intravenous (IV) Cannulation
IV Cannulation is a technique of placing a cannula inside a vein to gain venous access. The primary function of IV is administration of intravenous fluids and medicine. Blood samples can also be obtained through this type of cannulation. Arterial cannula is used in major operations and critical care areas to draw multiple blood samples at different times.
A flexible tube when inserted into the nostrils/mouth to deliver oxygen, anesthesia. It’s also used to measure airflow into and out of the nose/mouth. Nasal cannulas usually have multiple short, open-ended branches to facilitate insertion.
Purpose of Cannulation
As mentioned earlier, cannulation is process through which bodily fluids are either removed or added into ducts carrying these fluids. Administration of glucose, medication, nutrients, gases (oxygen), extraction of blood or urine are the primary purposes of cannulation.
Cannulation is also practiced in veterinary in emergency procedures to relieve pressure and bloating in domestic animals. Larger cannuals are used to study cattle’s digestive system too.
Standard IV needle is also used in a procedure called dermal punching (body piercing) for insertion of suspensions.
Usage, Contraindications and Complication
Cannulation requires professionally trained health workers because poorly performed process can result in further complications. However, it can be learned easily to be prepared for emergency situations. Finding the right spot before puncturing is foremost skill for anyone learning cannulation.
No absolute contraindication to IV cannulation exists, but peripheral venous access in an injured, infected or extremely burned case could create complications. Common complication includes hematoma characterized by collection of blood due to poorly punctured vein. Infiltration is another condition in which cannula penetrates into adjacent tissue instead of targeted vein. In case air, a thrombus or a tiny fragment of equipment itself finds its way into veins, it may cause medical condition called embolism. A mechanical or chemical irritation might cause inflammation of vein in case wrong site is chosen for cannulation.