HOME

TheInfoList



OR:

A cannula (; Latin meaning 'little reed'; plural or ) is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of samples. In simple terms, a cannula can surround the inner or outer surfaces of a
trocar A trocar (or trochar) is a medical or veterinary device that is made up of an awl (which may be a metal or plastic sharpened or non-bladed tip), a cannula (essentially a hollow tube), and a seal. Trocars are placed through the abdomen during lap ...
needle thus extending the effective needle length by at least half the length of the original needle. Its size mainly ranges from 14 to 24
gauge Gauge ( or ) may refer to: Measurement * Gauge (instrument), any of a variety of measuring instruments * Gauge (firearms) * Wire gauge, a measure of the size of a wire ** American wire gauge, a common measure of nonferrous wire diameter, es ...
. Different-sized cannula have different colours as coded. Decannulation is the permanent removal of a cannula (
extubation Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic tube into the trachea (windpipe) to maintain an open airway or to serve as a conduit through which to administer certain drugs. It is frequently ...
), especially of a
tracheostomy Tracheotomy (, ), or tracheostomy, is a surgical airway management procedure which consists of making an incision (cut) on the anterior aspect (front) of the neck and opening a direct airway through an incision in the Vertebrate trachea, trache ...
cannula, once a
physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
determines it is no longer needed for breathing.


Medicine

Cannulas normally come with a
trocar A trocar (or trochar) is a medical or veterinary device that is made up of an awl (which may be a metal or plastic sharpened or non-bladed tip), a cannula (essentially a hollow tube), and a seal. Trocars are placed through the abdomen during lap ...
inside. The trocar is a needle, which punctures the body in order to get into the intended space. Many types of cannulas exist:
Intravenous Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...
cannulas are the most common in hospital use. A variety of cannulas are used to establish
cardiopulmonary bypass Cardiopulmonary bypass (CPB) is a technique in which a machine temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and oxygen to the body. The CPB pump itself is often referred to as a he ...
in
cardiac surgery Cardiac surgery, or cardiovascular surgery, is surgery on the heart or great vessels performed by cardiac surgeons. It is often used to treat complications of ischemic heart disease (for example, with coronary artery bypass grafting); to corr ...
. A
nasal cannula The nasal cannula (NC) is a device used to deliver supplemental oxygen or increased airflow to a patient or person in need of respiratory help. This device consists of a lightweight tube which on one end splits into two prongs which are placed ...
is a piece of plastic tubing that runs under the nose and is used to administer oxygen.


Intravenous (IV) cannulation

A
venous Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
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. Insertion of the venous cannula is a painful procedure that can lead to anxiety and stress. Use of a
vapocoolant Freeze spray (cold spray or vapocoolant) is a type of aerosol spray product containing a liquified gas used for rapidly cooling surfaces, in medical and industrial applications. It is usually sold in hand-held spray cans. It may consist of vario ...
(cold spray) immediately before cannulation reduces pain during the procedure, without increasing the difficulty of cannulation. Complications may arise in the vein as a result of the cannulation procedure, the four main groups of complication are: *
hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...
: a collection of blood, which can result from failure to puncture the vein when the cannula is inserted or when the cannula is removed. The selection of an appropriate vein and gently applying pressure slightly above the insertion point on removal of the cannula may prevent this. *
infiltration Infiltration may refer to: Science, medicine, and engineering *Infiltration (hydrology), downward movement of water into soil *Infiltration (HVAC), a heating, ventilation, and air conditioning term for air leakage into buildings *Infiltration (me ...
: 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. *
embolism An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule ( fat embolism), a bubble of air or other gas (gas embolism), amniotic fluid (amniot ...
: this can be caused by air, a
thrombus A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of c ...
, or fragment of a catheter breaking off and entering the venous system. It can cause a
pulmonary embolism Pulmonary embolism (PE) is a blockage of an pulmonary artery, artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include dyspnea, shortness of breath, chest pain p ...
. 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. *
phlebitis Phlebitis (or Venitis) is inflammation of a vein, usually in the legs. It most commonly occurs in superficial veins. Phlebitis often occurs in conjunction with thrombosis and is then called thrombophlebitis or superficial thrombophlebitis. Unlike ...
: 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

A
nasal cannula The nasal cannula (NC) is a device used to deliver supplemental oxygen or increased airflow to a patient or person in need of respiratory help. This device consists of a lightweight tube which on one end splits into two prongs which are placed ...
or an oral–nasal cannula consists of a flexible tube, usually with multiple short, open-ended branches for comfortable insertion into the
nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...
s and/or
mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...
, and may be used for the delivery of a gas (such as pure
oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
), a gas mixture (as, for example, during
anesthesia Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), ...
), or to measure airflow into and out of the nose and/or mouth.


Tracheotomy tube

The removal of a tracheotomy tube is referred to as decannulation.


Veterinary use

A cannula is used in an emergency procedure to relieve pressure and bloating in cattle and sheep with
ruminal tympany Ruminal tympany, also known as ruminal bloat, is a disease of ruminant animals, characterized by an excessive volume of gas in the rumen. Ruminal tympany may be primary, known as frothy bloat, or secondary, known as free-gas bloat. In the rumen, fo ...
, due most commonly to their accidentally grazing wilted
legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...
or legume-dominant pastures, particularly
alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as w ...
,
ladino Ladino, derived from Latin, may refer to: * The register of Judaeo-Spanish used in the translation of religious texts, such as the Ferrara Bible *Ladino people, a socio-ethnic category of Mestizo or Hispanicized people in Central America especi ...
, and red and white clover. Cannulas are a component used in the insertion of the
Verichip A human microchip implant is any electronic device implanted subcutaneously (subdermally) usually via an injection. Examples include an identifying integrated circuit RFID device encased in silicate glass which is implanted in the body of a human ...
. Much larger cannulas are used to research about the digestive system of
cannulated cow A cannulated cow or fistulated cow refers to a cow that has been surgically fitted with a cannula. A cannula acts as a porthole-like device that allows access to the rumen of a cow, to perform research and analysis of the digestive system and to a ...
s.


Aesthetic medicine and anti-ageing

In
aesthetic medicine Aesthetic medicine is a branch of modern medicine that can be practiced only by medical professionals with training in aesthetics and lasers. It focuses on altering cosmetic appearance through the treatment of conditions including scars, skin laxit ...
, a blunt-tip cannula or microcannula (also called smooth tip microcannula, blunt tipped cannula, or simply microcannula) is a small tube with an edge that is not sharp and an extrusion port or pore near the tip which is designed for atraumatic subdermal injections of fluids or gels. Depending on the size of the internal diameter, it can be used either for the injection of cosmetic wrinkle fillers like hyaluronic acid, collagen, poly-L-lactic acid, CaHA, etc., or for fat transfer (
Liposuction Liposuction, or simply lipo, is a type of fat-removal procedure used in plastic surgery. Evidence does not support an effect on weight beyond a couple of months and does not appear to affect obesity-related problems. In the United States, lipo ...
). The American Society for Aesthetic Plastic surgery notes additional soft tissue fillers like calcium hydroxy-apatite and polymethylmethacrylate. The advantage of using these is that they are less painful, have less risk of bruising, have less swelling, and a better safety profile. Accidental intravascular injections are more difficult with blunt-tip microcannulas, reducing the risk of skin necrosis, ulcers, and embolization to the retinal artery which can result in blindness. Indeed, in May 2015, the USA issued a warning of these risks as an FDA Safety Communication on the "Unintentional Injection of Soft Tissue Filler Into Blood Vessels In the Face". In January 2012, the "Dermasculpt" microcannula was approved by the FDA for use in the United States for use with soft tissue fillers followed by the "Magic Needle", "Softfil", "TSK STERiGLIDE™ by Air-Tite Products", and "Sculpt-face". The primary structural differences between microcannulas is the distance of the extrusion port or pore from the tip (closer is more precise), the bluntness of the tip (tapered blunt tip is easier for entry), and the flexibility of the shaft (enough flexibility to move around sensitive structures but enough rigidity for precise placement). Since microcannula tips are blunt, a Pilot or Introducer needle is required for entry through the skin and the technique is to thread the microcannula through this tiny opening. Microcannula cosmetic injection techniques have been developed on how to best place cosmetic wrinkle fillers such as the Long MicroCannula Double Cross-Hatched Fan and the Wiggle Progression techniques. In April 2016, the concept of the use of microcannula to inject more than cosmetic fillers was first published. The technique of Microcannula Injected Local Anesthesia (MILA) was described on the use of microcannula to inject local anesthesia with less pain, bruising, and swelling. Also introduced were Accelerated Healing After Platelet-Rich Plasma (AHA-PRP), Accelerated Healing After Platelet-Rich Fibrin Matrix (AHA-PRFM), and the use of microcannula to dissolve Sculptra nodules. .


Body piercing

Cannulas are used in
body piercing Body piercing, which is 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, or where an implant could be inserted. The word ''piercing'' can refer to ...
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 A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves extraction of sampling (medicine), sample Cell (biology), cells or Biologica ...
without a cannula), and for inserting hooks for
suspensions In chemistry, a suspension is a heterogeneous mixture of a fluid that contains solid particles sufficiently large for sedimentation. The particles may be visible to the naked eye, usually must be larger than one micrometer, and will eventually ...
. During piercing, the
fistula A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow or ...
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

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 Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
. 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 is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, development ...
. 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 10,000 feet above sea level. 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 or cannulation is a set 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 c ...
.


See also

*
Catheter In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Cath ...
*
Hypodermic needle A hypodermic needle (from Greek ὑπο- (''hypo-'' = under), and δέρμα (''derma'' = skin)), one of a category of medical tools which enter the skin, called sharps, is a very thin, hollow tube with one sharp tip. It is commonly used w ...
*
Cannulated cow A cannulated cow or fistulated cow refers to a cow that has been surgically fitted with a cannula. A cannula acts as a porthole-like device that allows access to the rumen of a cow, to perform research and analysis of the digestive system and to a ...


References


External links

{{wiktionary
Decannulation, Cincinnati Children's Hospital Medical Center
Medical equipment