Intravenous therapy

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Intravenous therapy
Other namesIV therapy, iv therapy
ICD-9-CM 38.93

Intravenous therapy (IV) is a therapy that delivers fluids directly into a vein. The intravenous route of administration can be used both for injections, using a syringe at higher pressures; as well as for infusions, typically using only the pressure supplied by gravity. Intravenous infusions are commonly referred to as drips.

Therapy medical treatment

A therapy or medicaltreatment is the attempted remediation of a health problem, usually following a diagnosis.

In physics, a fluid is a substance that continually deforms (flows) under an applied shear stress, or external force. Fluids are a phase of matter and include liquids, gases and plasmas. They are substances with zero shear modulus, or, in simpler terms, substances which cannot resist any shear force applied to them.

Vein blood vessels that carry blood towards the heart

Veins are blood vessels that carry blood toward 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 blood to the heart. In contrast to veins, arteries carry blood away from the heart.


The intravenous route is the fastest way to deliver medications and fluid replacement throughout the body, because they are introduced directly into the circulation. Intravenous therapy may be used for fluid volume replacement, to correct electrolyte imbalances, to deliver medications, and for blood transfusions.

Fluid replacement medical practice of replenishing bodily fluid lost

Fluid replacement or fluid resuscitation is the medical practice of replenishing bodily fluid lost through sweating, bleeding, fluid shifts or other pathologic processes. Fluids can be replaced with oral rehydration therapy (drinking), intravenous therapy, rectally such as with a Murphy drip, or by hypodermoclysis, the direct injection of fluid into the subcutaneous tissue. Fluids administered by the oral and hypodermic routes are absorbed more slowly than those given intravenously.

Circulatory system Organ system for circulating blood in animals

The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients, oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.

Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis within the body. They help to regulate heart and neurological function, fluid balance, oxygen delivery, acid–base balance and much more. Electrolyte imbalances can develop by the following mechanisms: excessive ingestion; diminished elimination of an electrolyte; diminished ingestion; or excessive elimination of an electrolyte.

Types of access

A peripheral line placed on the hand Intravenous therapy 2007-SEP-13-Singapore.JPG
A peripheral line placed on the hand

Intravenous systems can be categorized by which type of vein the inserted tube, called the catheter, empties into.

Peripheral lines

A peripheral intravenous (PIV) line is used on peripheral veins (the veins in the arms, hands, legs and feet). This is the most common type of IV therapy used.

Peripheral vascular system Veins and arteries not in the chest or abdomen

The peripheral vascular system is the part of the circulatory system that consists of the veins and arteries not in the chest or abdomen. The peripheral arteries supply oxygenated blood to the body, and the peripheral veins lead deoxygenated blood from the capillaries in the extremities back to the heart.

Central lines

Illustration of a non-tunneled central venous access device Blausen 0181 Catheter CentralVenousAccessDevice NonTunneled.png
Illustration of a non-tunneled central venous access device

Central IV lines have their catheters that are advanced through a vein and empty into a large central vein (a vein within the torso), usually the superior vena cava , inferior vena cava or even the right atrium of the heart.

Central venous catheter Catheter placed into a large vein

A central venous catheter (CVC), also known as a central line, central venous line, or central venous access catheter, is a catheter placed into a large vein. Catheters can be placed in veins in the neck, chest, groin, or through veins in the arms. It is used to administer medication or fluids that are unable to be taken by mouth or would harm a smaller peripheral vein, obtain blood tests, and measure central venous pressure.

Superior vena cava One of two veinous trunks bringing deoxygenated blood back to the heart

The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein that receives venous return from the upper half of the body, above the diaphragm. Venous return from the lower half, below the diaphragm, flows through the inferior vena cava. The SVC is located in the anterior right superior mediastinum. It is the typical site of central venous access via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC.

Inferior vena cava One of two veinous trunks bringing deoxygenated blood back to the heart

The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. Its walls are rigid and it has valves so the blood does not flow down via gravity. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth lumbar vertebra.

Indications for a central line over the more common peripheral IV line commonly includes poor peripheral venous access for a PIV. Another common indication is when patients would require infusions over a prolonged period of time, such as antibiotic therapy over a few weeks for osteomyelitis. Another indication is when the substances to be administered could irritate the blood vessel lining such as total parenteral nutrition, whose high glucose content can damage blood vessels, and some chemotherapy regimens. There is less damage to the blood vessels because central veins have a larger diameter than peripheral veins, have faster blood flow, and would get diluted as it is quickly distributed to the rest of the body. Vasopressors (such as norepinephrine, vasopressin, epinephrine, phenylephrine, among others) are typically infused through central lines to minimize the risk of extravasation.

Chemotherapy treatment of cancer with one or more cytotoxic anti-neoplastic drugs

Chemotherapy is a type of cancer treatment that uses one or more anti-cancer drugs as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent, or it may aim to prolong life or to reduce symptoms. Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called medical oncology.

Other advantages are that multiple medications can be delivered at once, even if they would not be chemically compatible within a single tube as there is room for multiple parallel compartments (lumina) within the catheter. It is commonly believed that fluid can be pushed faster through a central line; however, the diameter of each lumen is often smaller than that of a large-bore peripheral cannula. Caregivers can also measure central venous pressure and other physiological variables through the central line. They are also longer and, as reflected by Poiseuille's law, require higher pressure to achieve the same flow, all other variables being equal.


A cannula 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 needle thus extending the effective needle length by at least half the length of the original needle. It is also called an intravenous (IV) cannula. Its size mainly ranges from 14 to 24 gauge. Different-sized cannula have different colours as coded.

Central venous pressure (CVP) is the blood pressure in the venae cavae, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood back into the arterial system. CVP is often a good approximation of right atrial pressure (RAP), although the two terms are not identical, as a pressure differential can sometimes exist between the venae cavae and the right atrium. CVP and RAP can differ when arterial tone is altered. This can be graphically depicted as changes in the slope of the venous return plotted against right atrial pressure.

Central IV lines carry risks of bleeding, infection, gangrene, thromboembolism and gas embolism (see Risks below). They are often more difficult to insert correctly as the veins are not usually palpable and rely on an experienced clinician knowing the appropriate landmarks and/or using an ultrasound probe to safely locate and enter the vein. Surrounding structures such as the pleura and carotid artery are also at risk of damage with the potential for pneumothorax or even cannulation of the artery.

There are several types of central IV access, depending on the route that the catheter takes from the outside of the body to the vein.

Peripherally inserted central catheter (PICC)

The PICC line is inserted through a sheath into a peripheral vein sometimes using the Seldinger technique or modified Seldinger technique, under ultrasound guidance, usually in the arm, and then carefully advanced upward until the catheter is in the superior vena cava or the right atrium. This is usually done by measuring the distance to an external landmark, such as the suprasternal notch, to estimate the optimal length. An X-ray must be used to verify that the tip is in the right place when fluoroscopy was not used during the insertion. More modern technology utilizes EKG technology to determine when the tip is in the correct location.

A PICC may have a single (single-lumen) tube and connector, two (double-lumen) or three (triple-lumen) compartments, each with its own external connector. Power-injectable PICCs are now available as well. From the outside, a single-lumen PICC resembles a peripheral IV line, except that the tubing is slightly wider.

The insertion site requires better protection than that of a peripheral IV line, due to the higher risk of serious infection if bacteria travel up the catheter. However, a PICC poses less of a systemic infection risk than other central IV lines, because the insertion site is usually cooler and drier than the sites typically used for other central lines. This helps to slow the growth of bacteria which could reach the bloodstream by traveling under the skin along the outside of the catheter.

The chief advantage of a PICC over other types of central lines is that it is safer to insert with a relatively low risk of uncontrollable bleeding and essentially no risks of damage to the lungs or major blood vessels. Although special training is required, a PICC does not require the skill level of a physician or surgeon. It is also externally unobtrusive, and with proper hygiene and care can be left in place for months to years if needed for patients who require extended treatment.

The chief disadvantage is that it must be inserted and then travel through a relatively small peripheral vein which can take a less predictable course on the way to the superior vena cava and is therefore somewhat more time consuming and more technically difficult to place in some patients. As a PICC travels through the axilla, it can also become kinked, causing poor function.

Tunneled lines

A Hickman line, a type of tunneled catheter, where it is inserted through the skin at the chest and tunnels through to insert into the jugular vein in the neck Hickman line catheter with 2 lumens.jpg
A Hickman line, a type of tunneled catheter, where it is inserted through the skin at the chest and tunnels through to insert into the jugular vein in the neck

While some central lines have their catheter pass through the skin and then directly into the vein, other central lines called "tunneled catheters" insert through the skin and then pass or "tunnel" a significant distance before inserting into the vein. This reduces the risk of infection, since bacteria from the skin surface are not able to travel directly into the vein. These catheters are often made of materials that resist infection and clotting. These include the Hickman line or Broviac catheter.

Implantable ports

A port (often referred to by brand names such as Port-a-Cath or MediPort) is a central venous line that does not have an external connector; instead, it has a small reservoir that is covered with silicone rubber and is implanted under the skin. Medication is administered intermittently by placing a small needle through the skin, piercing the silicone, into the reservoir. When the needle is withdrawn, the reservoir cover reseals itself. The cover can accept hundreds of needle sticks during its lifetime. It is possible to leave the ports in the patient's body for years; if this is done, the port must be accessed monthly and flushed with an anti-coagulant, or the patient risks it getting plugged up. If it is plugged, it becomes a hazard as a thrombus will eventually form with an accompanying risk of embolisation. Removal of a port is usually a simple outpatient procedure; however, installation is more complex and a good implant is fairly dependent on the skill of the radiologist. Ports cause less inconvenience and have a lower risk of infection than PICCs, and are therefore commonly used for patients on long-term intermittent treatment.

Midline catheter

A third type is a midline catheter which is inserted into a peripheral vein and advances through the vein, similar to a peripheral IV line, but falls short of emptying into a central vein.

Types of infusions

Continuous infusion

A continuous infusion is primarily used to correct fluid and electrolyte imbalances. This is as opposed to intermittent infusion, when a patient requires medications only at certain times, such as secondary IV and IV push.

Secondary IV

The tubing from the bag of fluid being administered that connects directly to the patient is called the primary tubing. Any additional IVs to be administered are connected to the primary tubing and are called secondary IV, or IV piggyback; [1] this is done instead of placing multiple catheters in the patient. When administering a secondary IV medication, the primary bag is held lower than the secondary bag so that the secondary medication can flow into the primary tubing, rather than fluid from the primary bag flowing into the secondary tubing. The fluid from the primary bag is needed to help flush any remaining medication from the secondary IV from the tubing into the patient.

IV push

Some medications are also given by IV "push" or bolus. A syringe containing the medication is connected to an access port in the primary tubing and the medication is administered through the port. The syringe plunger is pressed slowly, if it might irritate the vein or cause a too-rapid effect. Certain medications, such as potassium, are never to be administered by IV push because the spike in medication in the blood from the IV push could be fatal. Once a medicine has been injected into the fluid stream of the IV tubing, there must be some means of ensuring that it gets from the tubing to the patient. Usually this is accomplished by allowing the fluid stream to flow normally and thereby carry the medicine into the bloodstream; however, a second fluid injection is sometimes used, a "flush", following the injection to push the medicine into the bloodstream more quickly.

Medical uses

IV bags on a pole connected to IV lines Infuuszakjes.jpg
IV bags on a pole connected to IV lines

Substances that may be infused intravenously include volume expanders, blood-based products, blood substitutes, medications and nutrition.

Volume expanders

A person receiving intravenous fluid Intravenuos administration.jpg
A person receiving intravenous fluid

There are two main types of volume expander: crystalloids and colloids. Crystalloids are aqueous solutions of mineral salts or other water-soluble molecules. Colloids contain larger insoluble molecules, such as gelatin. Blood is a colloid.

The best way to determine if a person will benefit from fluids is by doing a passive leg raise followed by measuring the output from the heart. [4]


Medications may be mixed into the fluids mentioned above. Compared with other routes of administration, such as oral medications, the intravenous route is the fastest way to deliver fluids and medications throughout the body. The bioavailability of the IV medication is 100%, unlike oral medications where much of the medication is lost in digestion before entering circulation. Certain types of medications can only be given intravenously, such as when there is insufficient uptake by other routes of administration such as enterally. Examples include intravenous immunoglobulin and propofol.

Blood-based products

Saline and 5% glucose solution (Left), levofloxacin 750mg (Right) Glass IV.jpg
Saline and 5% glucose solution (Left), levofloxacin 750mg (Right)

A blood product (or blood-based product) is any component of blood which is collected from a donor for use in a blood transfusion. Blood transfusions can be life-saving in some situations, such as massive blood loss due to trauma, or can be used to replace blood lost during surgery. Blood transfusions may also be used to treat a severe anaemia or thrombocytopenia caused by a blood disease. People with hemophilia usually need a replacement of clotting factor, which is a small part of whole blood. People with sickle-cell disease may require frequent blood transfusions. Early blood transfusions consisted of whole blood, but modern medical practice commonly uses only components of the blood, such as fresh frozen plasma or cryoprecipitate.

Blood substitutes (also called 'artificial blood' or 'blood surrogates') are artificial substances aiming to provide an alternative to blood-based products acquired from donors. The main blood substitutes used today are volume expanders such as crystalloids and colloids mentioned above. Also, 'oxygen-carrying substitutes' are emerging.

Buffer solutions

Buffer solutions are used to correct acidosis or alkalosis. Lactated Ringer's solution also has some buffering effect. A solution more specifically used for buffering purpose is intravenous sodium bicarbonate.


Parenteral nutrition is feeding a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulas containing salts, glucose, amino acids, lipids and added vitamins.


An infusion pump suitable for a single IV line Infusionspumpe.JPG
An infusion pump suitable for a single IV line

A standard IV infusion set consists of a pre-filled, sterile container (glass bottle, plastic bottle or plastic bag) of fluids with an attachment that allows the fluid to flow one drop at a time, making it easy to see the flow rate (and also reducing air bubbles); a long sterile tube with a clamp to regulate or stop the flow; a connector to attach to the access device; and Y-sets to allow "piggybacking" of another infusion set onto the same line, e.g., adding a dose of antibiotics to a continuous fluid drip.

Infusion pumps

An infusion pump allows precise control over the flow rate and total amount delivered. The volume to be infused (VTBI) of the mainline IV bag is usually programmed for about 50 milliliters less than the stated volume of that IV bag to avoid letting the IV line or tubing run dry. The VTBI for a secondary bag or piggybag should usually be programmed for 30 to 50 milliliters more than is stated to be in that medication IV bag, to make sure that in addition to the bag being emptied, the entire medication dose is flushed through the IV tubing from the mainline bag. Because of its design, the short, secondary IV line cannot run dry. Thus, the registered nurse programs the IV pump for a 50 milliliter bag of IV antibiotics volume to be infused (VTBI) for at least 80 milliliters. The 100 milliliter bag of antibiotics usually needs a VTBI of about 140 milliliters. In cases where a change in the flow rate would not have serious consequences, or if pumps are not available, the drip is often left to flow simply by placing the bag above the level of the patient and using the clamp to regulate the rate; this is a gravity drip.

Hypodermic needle

The simplest form of intravenous access is by passing a hollow needle through the skin directly into the vein. This needle can be connected directly to a syringe (used either to withdraw blood or deliver its contents into the bloodstream) or may be connected to a length of tubing and thence whichever collection or infusion system is desired.

The most convenient site is often the arm, especially the veins on the back of the hand, or the median cubital vein at the elbow, but any identifiable vein can be used. Often it is necessary to use a tourniquet which restricts the venous drainage of the limb and makes the vein bulge. Once the needle is in place, it is common to draw back slightly on the syringe to aspirate blood, thus verifying that the needle is really in a vein. The tourniquet should be removed before injecting to prevent extravasation of the medication.

Drip chamber

Many systems of administration employ a drip chamber, which prevents air from entering the blood stream (air embolism), and allows an estimation of flow rate.

Peripheral cannula

A nurse inserting an 18-gauge IV needle with cannula Intravenous attempt.jpg
A nurse inserting an 18-gauge IV needle with cannula
An arm board is recommended for immobilizing the extremity for cannulation of the hand, the foot or the antecubital fossa in children. Pediatric patients receiving chemotherapy.jpg
An arm board is recommended for immobilizing the extremity for cannulation of the hand, the foot or the antecubital fossa in children.

A peripheral cannula is the most common intravenous access method utilized in both hospitals and pre-hospital services. A peripheral IV line (PVC or PIV) consists of a short catheter (a few centimeters long) inserted through the skin into a peripheral vein (any vein not situated in the chest or abdomen). This is usually in the form of a cannula-over-needle device, in which a flexible plastic cannula comes mounted over a metal trocar. Once the tip of the needle and cannula are introduced into the vein via venipuncture, the cannula is advanced inside the vein over the trocar to the appropriate position and secured, the trocar is then withdrawn and discarded. Blood samples may be drawn directly after the initial IV cannula insertion.

Any accessible vein can be used although arm and hand veins are used most commonly, with leg and foot veins used to a much lesser extent. In infants, the scalp veins are sometimes used.

The caliber of needles and catheters can be given in Birmingham gauge or French gauge. A Birmingham gauge of 14 is a very large cannula (used in resuscitation settings) and 24-26 is the smallest. The most common sizes are 16-gauge (midsize line used for blood donation and transfusion), 18- and 20-gauge (all-purpose line for infusions and blood draws), and 22-gauge (all-purpose pediatric line). 12- and 14-gauge peripheral lines are capable of delivering large volumes of fluid very fast, accounting for their popularity in emergency medicine. These lines are frequently called "large bores" or "trauma lines".

To make the procedure more tolerable for children, medical staff may apply a topical local anaesthetic (such as EMLA or Ametop) to the skin of the chosen venipuncture area about 45 minutes beforehand.

The part of the catheter that remains outside the skin is called the connecting hub; it can be connected to a syringe or an intravenous infusion line, or capped with a heplock or saline lock, a needleless connection filled with a small amount of heparin or saline solution to prevent clotting, between uses of the catheter. Ported cannulae have an injection port on the top that is often used to administer medicine.

In cases of shock, a central venous catheter, a peripherally inserted central catheter (PICC), venous cutdown or intraosseous infusion may be necessary.

If the cannula is not sited correctly, or the vein is particularly fragile and ruptures, blood may extravasate into the surrounding tissues, this situation is known as a blown vein or "tissuing". Using this cannula to administer medications causes extravasation of the drug which can lead to edema, causing pain and tissue damage, and even necrosis depending on the medication. The person attempting to obtain the access must find a new access site proximal to the "blown" area to prevent extravasation of medications through the damaged vein. For this reason it is advisable to site the first cannula at the most distal appropriate vein.

If a patient needs frequent venous access, the veins may scar and narrow, making any future access extremely difficult or impossible.

A peripheral IV cannot be left in the vein indefinitely out of concern for the risk of infection and phlebitis, among other potential complications. However, recent studies have found that there is no increased risk of complications in patients whose IVs were replaced only when clinically indicated versus patients whose IVs were replaced routinely. [6] [ needs update ] Thus, it is becoming more common to replace IVs only when clinically indicated. There is no need to replace peripheral IVs more frequently than 72–96 hours as long as the IV was placed aseptically. [7]

Catheter shearing is a very infrequent complication, but a very real danger. Shearing occurs when part of the catheter is cut by the sharp bevelled edge of the trochar. The sheared section may completely separate from the main body of the catheter, and become free floating in the blood stream. The majority of the time, it is due to poor technique, but infrequently a poorly manufactured catheter may break from the hub or shear. Infection, and a foreign body embolus are the two threats to the patient.[ citation needed ]

Pressure bags

A rapid infuser can be used if the patient requires a high flow rate and the IV access device is of a large enough diameter to accommodate it. This is either an inflatable cuff placed around the fluid bag to force the fluid into the patient or a similar electrical device that may also heat the fluid being infused.

Adverse effects


Iranian soldier holding IV bag Iranian soldier holding IV bag during Iran-Iraq war.jpeg
Iranian soldier holding IV bag

An injection inherently causes pain when the skin is broken and is medically invasive. In cases in which a choice between intravenous therapy and oral treatment may be made to achieve the same outcome, such as in the case of mild or moderate dehydration treatment (assuming oral rehydration therapy is an option), then one should avoid using intravenous therapy in place of the less invasive oral option. [8] Children in emergency departments being treated for dehydration in particular have better outcomes with oral treatment because it does not cause the pain or risk the complications of an injection. [8]

Cold spray can decrease the pain of putting in an IV. [9]


Any break in the skin carries a risk of infection. Although IV insertion is an aseptic procedure, skin-dwelling organisms such as Coagulase-negative staphylococcus or Candida albicans may enter through the insertion site around the catheter, or bacteria may be accidentally introduced inside the catheter from contaminated equipment. Moisture introduced to unprotected IV sites through washing or bathing substantially increases the infection risks.

Infection of IV sites is usually local, causing easily visible swelling, redness, and fever. If bacteria do not remain in one area but spread through the bloodstream, the infection is called sepsis and can be rapid and life-threatening. An infected central IV poses a higher risk of sepsis, as it can deliver bacteria directly into the central circulation.


Phlebitis is inflammation of a vein that may be caused by infection, the mere presence of a foreign body (the IV catheter) or the fluids or medication being given. Symptoms are warmth, swelling, pain, and redness around the vein. The IV device must be removed and if necessary re-inserted into another extremity.

Due to frequent injections and recurring phlebitis, scar tissue can build up along the vein. The peripheral veins of intravenous drug addicts, and of cancer patients undergoing chemotherapy, become sclerotic and difficult to access over time, sometimes forming a hard, painful “venous cord”.

Infiltration / extravasation

Infiltration occurs when an IV fluid or medication accidentally enters the surrounding tissue rather than the vein. It may occur when the vein itself ruptures (the elderly are particularly prone to fragile veins due to a paucity of supporting tissues), when the vein is damaged during insertion of the intravascular access device, when the device is not sited correctly, from increased vein porosity or when the entry point of the device into the vein becomes the path of least resistance (e.g. if a cannula is in a vein for some time, the vein may scar and close and the only way for fluid to leave is along the outside of the cannula where it enters the vein). Infiltration is an inadvertent administration of a nonvesicant solution/drug into the tissue, which happens so often when the tourniquet isn't removed in a timely fashion. Infiltration is characterized by coolness and pallor to the skin as well as localized swelling or edema. It is treated by removing the intravenous access device and elevating the affected limb so that the collected fluids can drain away. Sometimes injections of hyaluronidase can be used to speed the dispersal of the fluid/drug. Infiltration is one of the most common adverse effects of IV therapy [10] and is usually not serious unless the infiltrated fluid is a medication damaging to the surrounding tissue, most commonly a vesicant or chemotherapeutic agent, in which case it is called extravasation and extensive necrosis can occur. [11] [12]

Fluid overload

This occurs when fluids are given at a higher rate or in a larger volume than the system can absorb or excrete. Possible consequences include hypertension, heart failure, and pulmonary edema.


The human body is at risk of accidentally induced hypothermia when large amounts of cold fluids are infused. Rapid temperature changes in the heart may precipitate ventricular fibrillation.

Electrolyte imbalance

Administering a too-diluted or too-concentrated solution can disrupt the patient's balance of sodium, potassium, magnesium, chloride, and other electrolytes. Hospital patients usually receive blood tests to monitor these levels. It is essential to correct these imbalances if they occur, as they can lead to the clinical symptoms of electrolyte imbalance, which, if left untreated, can lead to acidosis/alkalosis, and ultimately death.


A blood clot or other solid mass, as well as an air bubble, can be delivered into the circulation through an IV and end up blocking a vessel; this is called embolism. It is nearly impossible to inject air through a peripheral IV at a dangerous rate. The risk is greater with a central IV.

Air bubbles of less than 30 microliters are thought to dissolve into the circulation harmlessly. A larger amount of air, if delivered all at once, can cause life-threatening damage, or, if extremely large (3-8 milliliters per kilogram of body weight), can stop the heart.

One reason veins are preferred over arteries for intravascular administration is because the flow will pass through the lungs before passing through the body. Air bubbles can leave the blood through the lungs. A patient with a right-to-left shunt is vulnerable to embolism from smaller amounts of air. Fatality by air embolism is rare, although this may be in part because it is so difficult to determine when this is the cause of death.


Intravenous glucose is used in some Asian countries such as Korea as a pick-me-up, for "energy," but is not a part of routine medical care in the United States where a glucose solution is a prescription drug. Asian immigrants to the United States are at risk if they seek intravenous glucose treatment. It may be had at store-front clinics catering to Asian immigrants, but, despite having no more effect than drinking sugared water, poses medical risks such as the possibility of infection. It is commonly called "ringer." [13]

Use in sports

IV rehydration was formerly a common technique for athletes. [14] The World Anti-Doping Agency (WADA) prohibits intravenous injection of more than 100mL per 12 hours, except under a medical exemption. [14] The United States Anti-Doping Agency notes that, as well as the dangers inherent in IV therapy, "IVs can be used to change blood test results (such as hematocrit where EPO or blood doping is being used), mask urine test results (by dilution) or by administering prohibited substances in a way that will more quickly be cleared from the body in order to beat an anti-doping test". [14] Sportspeople suspended after attending boutique IV clinics include footballer Samir Nasri in 2017 [15] and swimmer Ryan Lochte in 2018. [16]

Use for hangover treatment

In the 1960s, John Myers developed the "Myers' cocktail", a non-prescription IV solution of vitamins and minerals marketed as a hangover cure and general wellness remedy. [17] The first "boutique IV" clinic, offering similar treatments, opened in Tokyo in 2008. [17] These clinics, whose target market was described by Elle as "health nuts who moonlight as heavy drinkers", have been publicized in the 2010s by glamorous celebrity customers. [17]


Intravenous technology stems from studies on cholera treatment in 1831 by Dr Thomas Latta of Leith. [18] Intravenous therapy was pioneered by Italian physician Guido Baccelli in the late 1890s [19] and further developed in the 1930s by Hirschfeld, Hyman and Wanger [20] [21] but was not widely available until the 1950s. [22]

See also

Related Research Articles

Catheter Medical tubes inserted in the body to extract or administer substances

In medicine, a catheter 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. By modifying the material or adjusting the way catheters are manufactured, it is possible to tailor catheters for cardiovascular, urological, gastrointestinal, neurovascular, and ophthalmic applications.

Dialysis catheter

A dialysis catheter is a catheter used for exchanging blood to and from a hemodialysis machine and a patient.

Peripherally inserted central catheter Catheter intended for long periods of use

A peripherally inserted central catheter, less commonly called a percutaneous indwelling central catheter, is a form of intravenous access that can be used for a prolonged period of time or for administration of substances that should not be done peripherally. It is a catheter that enters the body through the skin (percutaneously) at a peripheral site, extends to the superior vena cava, and stays in place for days or weeks.

Intraosseous infusion the medical process of introducing medication directly into the bone marrow

Intraosseous infusion (IO) is the process of injecting directly into the marrow of a bone. This provides a non-collapsible entry point into the systemic venous system. This technique is used to provide fluids and medication when intravenous access is not available or not feasible. Intraosseous infusions allow for the administered medications and fluids to go directly into the vascular system. A comparison of intravenous (IV), intramuscular (IM), and intraosseous (IO) routes of administration concluded that the intraosseous route is demonstrably superior to intramuscular and comparable to intravenous administration. This route of fluid and medication administration is an alternative one to the preferred intravascular route when the latter cannot be established in a timely manner. Intraosseous infusions are utilized when trauma patients have compromised intravenous access and need immediate delivery of life saving fluids and medications.

Infusion pump

An infusion pump infuses fluids, medication or nutrients into a patient's circulatory system. It is generally used intravenously, although subcutaneous, arterial and epidural infusions are occasionally used.

Extravasation is the leakage of intravenously (IV) infused, and potentially damaging, medications into the extravascular tissue around the site of infusion. The leakage can occur through brittle veins in the elderly, through previous venipuncture access, or through direct leakage from wrongly positioned venous access devices. When the leakage is not of harmful consequence it is known as infiltration. Extravasation of medication during intravenous therapy is an adverse event related to therapy that, depending on the medication, amount of exposure, and location, can potentially cause serious injury and permanent harm, such as tissue necrosis. Milder consequences of extravasation include irritation, characterized by symptoms of pain and inflammation, with the clinical signs of warmth, erythema, or tenderness.

Infiltration is the diffusion or accumulation of foreign substances or in amounts in excess of the normal. The material collected in those tissues or cells is called infiltrate.

Vascular access refers to a rapid, direct method of introducing or removing devices or chemicals from the bloodstream. In hemodialysis, vascular access is used to remove the patient's blood so that it can be filtered through the dialyzer. Three primary methods are used to gain access to the blood: an intravenous catheter, an arteriovenous fistula (AV) or a synthetic graft. In the latter two, needles are used to puncture the graft or fistula each time dialysis is performed.

Venous cutdown is an emergency procedure in which the vein is exposed surgically and then a cannula is inserted into the vein under direct vision. It is used to get vascular access in trauma and hypovolemic shock patients when peripheral cannulation is difficult or impossible. The saphenous vein is most commonly used. This procedure has fallen out of favor with the development of safer techniques for central venous catheterization such as the Seldinger technique, the modified Seldinger technique, intraosseous infusion, as well as the use of ultrasound guidance for placement of central venous catheters without using the cutdown technique.

Winged infusion set

A winged infusion set—also known as "butterfly" or "scalp vein" set—is a device specialized for venipuncture: i.e. for accessing a superficial vein for either intravenous injection or phlebotomy. It consists, from front to rear, of a hypodermic needle, two bilateral flexible "wings", flexible small-bore transparent tubing, and lastly a connector. This connector attaches to another device: e.g. syringe, vacuum tube holder/hub, or extension tubing from an infusion pump or gravity-fed infusion / transfusion bag/bottle.

Port (medical) Small medical appliance that is installed beneath the skin

In medicine, a port is a small medical appliance that is installed beneath the skin. A catheter connects the port to a vein. Under the skin, the port has a septum through which drugs can be injected and blood samples can be drawn many times, usually with less discomfort for the patient than a more typical "needle stick".

A volume expander is a type of intravenous therapy that has the function of providing volume for the circulatory system. It may be used for fluid replacement.

Peripheral venous catheter

In medicine, a peripheral venous catheter (PVC), peripheral venous line or peripheral venous access catheter is a catheter placed into a peripheral vein for intravenous therapy such as medication fluids. Upon insertion, the line can be used to draw blood.

ICU Medical, Inc. is a San Clemente, California-based company with global operations that develops, manufactures, and sells medical technologies used in vascular therapy, oncology, and critical care applications. ICU Medical’s products are designed to prevent bloodstream infections and protect healthcare workers from exposure to infectious diseases or hazardous drugs. ICU Medical's product line includes intravenous therapy (IV) products, pumps, needle-free vascular access devices, custom infusion sets, closed system hazardous drug handling devices and systems, sensor catheters, needle-free closed blood sampling systems, and hemodynamic monitoring systems.

Venous access is any kind of way to access the bloodstream through the veins, either to administer intravenous therapy, parenteral nutrition, to obtain blood for analysis, or of blood-based treatments such as dialysis or apheresis. Central venous catheters (CVCs) may also be used to measure the central venous pressure.

In medicine, vascular access is a means of accessing the circulatory system through the peripheral or central vascular system in order to obtain blood or deliver medications. A vascular access procedure involves insertion of a sterile plastic tube called a catheter into a blood vessel. Types of catheters can be either peripherally or centrally located. Peripheral catheters are approximately one inch long and are inserted into the small veins of the forearm. Central catheters are bigger and longer and are inserted into the large veins of the extremities, neck, or chest. Central venous catheters is the primary modality used for delivery of chemotherapeutic agents. The duration of central venous catheterization is dependent on the type of treatment given.

Intravenous (IV) iron infusion is a therapy in which a combination of iron and saline solution is delivered directly into the bloodstream through a vein, in patients suffering iron deficiency, iron-deficiency anaemia and chronic kidney disease. IV iron infusions are recommended when oral iron supplementation fails to adequately restore iron and haemoglobin levels in the blood. The intravenous method is a fast and effective way of delivering iron throughout the body, and is used because iron can be administered instantly rather than gradually overtime.


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Further reading