Cannula
Encyclopedia
A cannula or canula is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of data. In simple terms, a cannula can surround the inner or outer surfaces of a trocar
needle thus extending needle approach to a vein by half or more of the length of the introducer.
Decannulation is the permanent removal of a cannula (extubation
), especially of a tracheostomy cannula, once a physician
determines it is no longer needed for breathing.
attached, which allows puncturing of the body in order to get into the intended space. There are, however, 11 different kinds of cannula:
Intravenous cannulae are the most common in hospital use. A variety of cannulae are used to establish cardiopulmonary bypass in cardiac surgery
. Nasal cannula
is a piece of plastic tubing that runs under the nose and is used to administer oxygen.
cannula is inserted into a vein, primarily for the administration of intravenous fluids, for obtaining blood samples and for administering medicines. An arterial cannula is inserted into an artery, commonly the radial artery, and is used during major operations and in critical care areas to measure beat-to-beat blood pressure and to draw repeated blood samples.
Complications may arise in the vein as a result of the cannulation procedure, the four main groups of complication are:
A nasal cannula
or an oral–nasal cannula consists of a flexible tube, usually with multiple short, open-ended branches for comfortable insertion into the nostril
s and/or mouth
, and may be used for the delivery of a gas (such as pure oxygen
), a gas mixture (as, for example, during anesthesia
), or to measure airflow into and out of the nose and/or mouth.
ing in cattle due most commonly to their accidentally grazing wilted legume or legume-dominant pastures, particularly alfalfa
, ladino, and red and white clover
.
They are also a component used in the insertion of the Verichip
.
when using a standard IV needle (usually between 18GA and 12GA, although may be as large as 0GA, in which case the procedure is known as dermal punching and uses a biopsy punch without a cannula), and for inserting hooks for suspensions
.
During piercing, the fistula
is created by inserting the needle. The needle is then removed, leaving the cannula in place, which is sometimes trimmed down. The cannula is then removed and sterile jewelry is inserted into the fistula simultaneously, in order to minimise trauma to the fresh fistula caused by insertion of blunt-ended jewelry.
In biological research, a push-pull cannula, which both withdraws and injects fluid, can be used to determine the effect of a certain chemical on a specific cell
. The push part of the cannula is filled with a physiological solution plus the chemical of interest and is then injected slowly into the local cellular environment of a cell. The pull cannula then draws liquid from the extracellular medium, thus measuring the cellular response to the chemical of interest. This technique is especially used for neuroscience
.
In general aviation, a cannula refers to a piece of plastic tubing that runs under the nose and is used to administer oxygen in non-pressurized aircraft flying above 10,000 feet above sea level in Canada and above 12,500 feet above sea level in the United States.
In synthetic chemistry, a cannula refers to a piece of stainless steel or plastic tubing used to transfer liquids or gases from one vessel to another without exposure to air. See more at Cannula transfer
.
Trocar
A trocar is a medical instrument with a sharply pointed end, often three-sided, that is used inside a hollow cylinder to introduce this into blood vessels or body cavities...
needle thus extending needle approach to a vein by half or more of the length of the introducer.
Decannulation is the permanent removal of a cannula (extubation
Intubation
Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs...
), especially of a tracheostomy cannula, once a physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
determines it is no longer needed for breathing.
Medicine
Cannulae normally come with a trocarTrocar
A trocar is a medical instrument with a sharply pointed end, often three-sided, that is used inside a hollow cylinder to introduce this into blood vessels or body cavities...
attached, which allows puncturing of the body in order to get into the intended space. There are, however, 11 different kinds of cannula:
- Bias Grind
- Vet Point
- Lancet Point
- Deflected point (Anti-Coring)
- Pencil Point
- Closed-End Consistent Wall
- Welded "Ball" End
- Bullet Point
- Razor Edge
- Probe Point (Blunt End)
- Trocar
Intravenous cannulae are the most common in hospital use. A variety of cannulae are used to establish cardiopulmonary bypass in cardiac surgery
Cardiac surgery
Cardiovascular surgery is surgery on the heart or great vessels performed by cardiac surgeons. Frequently, it is done to treat complications of ischemic heart disease , correct congenital heart disease, or treat valvular heart disease from various causes including endocarditis, rheumatic heart...
. Nasal cannula
Nasal cannula
The nasal cannula is a device used to deliver supplemental oxygen or airflow to a patient or person in need of respiratory help. This device consists of a plastic tube which fits behind the ears, and a set of two prongs which are placed in the nostrils. Oxygen flows from these prongs...
is a piece of plastic tubing that runs under the nose and is used to administer oxygen.
Intravenous (IV) cannulation
A venousIntravenous therapy
Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein. The word intravenous simply means "within a vein". Therapies administered intravenously are often called specialty pharmaceuticals...
cannula is inserted into a vein, primarily for the administration of intravenous fluids, for obtaining blood samples and for administering medicines. An arterial cannula is inserted into an artery, commonly the radial artery, and is used during major operations and in critical care areas to measure beat-to-beat blood pressure and to draw repeated blood samples.
Complications may arise in the vein as a result of the cannulation procedure, the four main groups of complication are:
- hematomaHematomaA hematoma, or haematoma, is a localized collection of blood outside the blood vessels, usually in liquid form within the tissue. This distinguishes it from an ecchymosis, which is the spread of blood under the skin in a thin layer, commonly called a bruise...
: a collection of blood, which can result from failure to puncture the vein when the cannula is inserted or when the cannula is removed. Selection of an appropriate vein and gently applying pressure slightly above the insertion point on removal of the cannula may prevent this. - infiltrationInfiltration (medical)Infiltration is the diffusion or accumulation of substances not normal to it or in amounts in excess of the normal. The material collected in those tissues or cells is called infiltrate.-Classification:...
: when infusate enters the subcutaneous tissue instead of the vein. To prevent this, a cannula with accurate trim distances may be used. It is essential to fix the cannula in place firmly. - embolismEmbolismIn medicine, an embolism is the event of lodging of an embolus into a narrow capillary vessel of an arterial bed which causes a blockage in a distant part of the body.Embolization is...
: this can be caused by air, a thrombus, or fragment of a catheter breaking off and entering the venous system. Such things can go on to lodge in an artery, blocking circulation to the corresponding area. Air emboli can be avoided by making sure that there is no air in the system. A thromboembolism can be avoided by using a smaller cannula. - phlebitisPhlebitisPhlebitis is an inflammation of a vein, usually in the legs.When phlebitis is associated with the formation of blood clots , usually in the deep veins of the legs, the condition is called thrombophlebitis...
: an inflammation of the vein resulting from mechanical or chemical irritation or from an infection. Phlebitis can be avoided by carefully choosing the site for cannulation and by checking the type of infusate used.
Nasal cannulation and oral-nasal cannulation
Nasal cannula
The nasal cannula is a device used to deliver supplemental oxygen or airflow to a patient or person in need of respiratory help. This device consists of a plastic tube which fits behind the ears, and a set of two prongs which are placed in the nostrils. Oxygen flows from these prongs...
or an oral–nasal cannula consists of a flexible tube, usually with multiple short, open-ended branches for comfortable insertion into the nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s and/or mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
, and may be used for the delivery of a gas (such as pure oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
), a gas mixture (as, for example, during anesthesia
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
), or to measure airflow into and out of the nose and/or mouth.
Veterinary use
A cannula is also used in an emergency procedure to relieve pressure and bloatBloat
Bloat is a medical condition in which the stomach becomes overstretched by excessive gas content. It is also commonly referred to as torsion, gastric torsion, and gastric dilatation-volvulus when the stomach is also twisted. The word bloat is often used as a general term to cover gas distension...
ing in cattle due most commonly to their accidentally grazing wilted legume or legume-dominant pastures, particularly alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
, ladino, and red and white clover
Clover
Clover , or trefoil, is a genus of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes...
.
They are also a component used in the insertion of the Verichip
VeriChip
VeriChip was the only Food and Drug Administration -approved human-implantable radio-frequency identification microchip. It was marketed by PositiveID, a subsidiary of Applied Digital Solutions, and it received United States FDA approval in 2004. Its manufacture and marketing were discontinued in...
.
Body piercing
Cannulae are used in body piercingBody piercing
Body piercing, a form of body modification, is the practice of puncturing or cutting a part of the human body, creating an opening in which jewelry may be worn. The word piercing can refer to the act or practice of body piercing, or to an opening in the body created by this act or practice...
when using a standard IV needle (usually between 18GA and 12GA, although may be as large as 0GA, in which case the procedure is known as dermal punching and uses a biopsy punch without a cannula), and for inserting hooks for suspensions
Suspension (body modification)
A suspension is the act of suspending a human body from hooks that have been put through body piercings. These piercings are temporary and are performed just prior to the actual suspension.- Method :...
.
During piercing, the fistula
Fistula
In medicine, a fistula is an abnormal connection or passageway between two epithelium-lined organs or vessels that normally do not connect. It is generally a disease condition, but a fistula may be surgically created for therapeutic reasons.-Locations:Fistulas can develop in various parts of the...
is created by inserting the needle. The needle is then removed, leaving the cannula in place, which is sometimes trimmed down. The cannula is then removed and sterile jewelry is inserted into the fistula simultaneously, in order to minimise trauma to the fresh fistula caused by insertion of blunt-ended jewelry.
Non-medical use
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
. The push part of the cannula is filled with a physiological solution plus the chemical of interest and is then injected slowly into the local cellular environment of a cell. The pull cannula then draws liquid from the extracellular medium, thus measuring the cellular response to the chemical of interest. This technique is especially used for neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
.
In general aviation, a cannula refers to a piece of plastic tubing that runs under the nose and is used to administer oxygen in non-pressurized aircraft flying above 10,000 feet above sea level in Canada and above 12,500 feet above sea level in the United States.
In synthetic chemistry, a cannula refers to a piece of stainless steel or plastic tubing used to transfer liquids or gases from one vessel to another without exposure to air. See more at Cannula transfer
Cannula transfer
Cannula transfer or cannulation is a subset of air-free techniques used with a Schlenk line, in transferring liquid or solution samples between reaction vessels via cannulae, avoiding atmospheric contamination. While the syringes are not the same as cannulae, the techniques remain relevant.There...
.