Intravenous therapy or
IV therapy is the giving of
liquidLiquid is one of the principal states of matter. A liquid is a fluid that has the particles loose and can freely form a distinct surface at the boundaries of its bulk material. The surface is a free surface where the liquid is not constrained by a container....
substances directly into a
veinIn the circulatory system, 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...
. It can be intermittent or continuous; continuous administration is called an
intravenous drip. The word
intravenous simply means "within a
veinIn the circulatory system, 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...
", but is most commonly used to refer to IV therapy. Therapies administered intravenously are often called
specialty pharmaceuticals.
Compared with other
routes of administrationA route of administration in pharmacology and toxicology is the path by which a drug, fluid, poison, or other substance is brought into contact with the body....
, the intravenous route is the fastest ways to deliver fluids and medications throughout the body.
Intravenous therapy or
IV therapy is the giving of
liquidLiquid is one of the principal states of matter. A liquid is a fluid that has the particles loose and can freely form a distinct surface at the boundaries of its bulk material. The surface is a free surface where the liquid is not constrained by a container....
substances directly into a
veinIn the circulatory system, 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...
. It can be intermittent or continuous; continuous administration is called an
intravenous drip. The word
intravenous simply means "within a
veinIn the circulatory system, 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...
", but is most commonly used to refer to IV therapy. Therapies administered intravenously are often called
specialty pharmaceuticals.
Compared with other
routes of administrationA route of administration in pharmacology and toxicology is the path by which a drug, fluid, poison, or other substance is brought into contact with the body....
, the intravenous route is the fastest ways to deliver fluids and medications throughout the body. Some medications, as well as
blood transfusionBlood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. 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...
s and
lethal injectionLethal injection refers to the practice of injecting a criminal with a fatal dose of drugs for the express purpose of executing the subject...
s, can only be given intravenously.
Needle and syringe
The simplest form of intravenous access is a
syringeA syringe is a simple piston pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...
with an attached
hypodermic needleA hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body or extract liquids from the body...
. The needle is inserted through the skin into a vein, and the contents of the syringe are injected through the needle into the bloodstream. This is most easily done with an arm vein, especially one of the metacarpal veins. Often it is necessary to use a
tourniquetAn emergency tourniquet is a tightly tied band applied around a body part sometimes used in an attempt to stop severe traumatic bleeding. Tourniquets are also used during venipuncture and other medical procedures. Severe bleeding means the loss of more than 1,000 ml of blood. This flow of blood...
first to make 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; then the tourniquet is removed before injecting.
Peripheral IV lines
This is the most common intravenous access method in both
hospitalA hospital is an institution for health care providing patient treatment by specialized staff and equipment, and often but not always providing for longer-term patient stays....
s and pre-hospital services. A
peripheral IV lineIn medicine, a peripheral venous catheter is a catheter placed into a peripheral vein in order to administer medication or fluids...
consists of a short
catheterIn medicine a catheter is a tube that can be inserted into a body cavity, duct or vessel. Catheters thereby allow drainage, injection of fluids or access by surgical instruments. The process of inserting a catheter is catheterization. In most uses a catheter is a thin, flexible tube , although...
(a few centimeters long) inserted through the skin into a
peripheral veinPeripheral Veins are the veins not in the chest or abdomen . These veins lead deoxygenated blood from the capillaries in the extremities back to the heart....
, any vein that is not in the chest or abdomen. There are times, however, when underlying physiological factors (obesity, peripheral vascular disease and IV drug abuse, to name a few) make insertion into any available vein a medical necessity—particularly if the patient is
exsanguinatingExsanguination is the fatal process of total hypovolemia . It is most commonly known as "bleeding to death"...
. The adage "time is tissue" should be paramount during times like these or if the patient is at risk for a cardiac event.
ArmIn anatomy, an arm is one of the upper limbs of an animal. The term arm can also be used for analogous structures, such as one of the paired upper limbs of a four-legged animal, or the arms of cephalopods....
and
handThe hands are the two intricate, prehensile, multi-fingered body parts normally located at the end of each arm of a primate. They are the chief organs for physically manipulating the environment, used for both gross motor skills and fine motor skills...
veins are typically used although
legŁęg may refer to the following places in Poland:*A former name for the town of Ełk *Łęg, Lower Silesian Voivodeship *Łęg, Kuyavian-Pomeranian Voivodeship *Łęg, Łódź Voivodeship...
and
footThe foot is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion...
veins are occasionally used. Veins in the arm are the common site in emergency settings, commonly performed by nurses. On infants the
scalpThe scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly.-Layers:It is usually described as having five layers, which can be remembered with the mnemonic "SCALP":....
veins are sometimes used. The part of the catheter that remains outside the skin is called the connecting hub; it can be connected to a
syringeA syringe is a simple piston pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...
or an intravenous infusion line, or capped with a
bungBung may refer to:* Bung, an apparatus used to seal a container* Bung Bong, Victoria, in Australia* Bung, Nepal, a Village Development Committee in Nepal* Bung Enterprises, a defunct Hong Kong-based manufacturer of video game accessories...
between treatments. Ported
cannulaA cannula or canula is a tube that can be inserted into the body, often for the delivery or removal of fluid....
e have an injection port on the top that is often used to administer medicine. The caliber of cannula is commonly indicated in
gaugeAmerican wire gauge , also known as the Brown & Sharpe wire gauge, is a standardized wire gauge system used since 1857 predominantly in the United States for the diameters of round, solid, nonferrous, electrically conducting wire...
, with 14 being a very large cannula (used in resuscitation settings) and 24-26 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 actually deliver equivalent volumes of fluid faster than central lines, accounting for their popularity in emergency medicine; these lines are frequently called "large bores" or "trauma lines".
Blood can be drawn from a peripheral IV if necessary, but only if it is in a relatively large vein and only if the IV is newly inserted. Blood draws are typically taken with specialized IV access sets known as phlebotomy kits, and once the draw is complete, the needle is removed and the site is not used again. If a patient needs frequent venous access, the veins may scar and narrow, making any future access extremely difficult or impossible; this situation is known as a "blown vein," and the person attempting to obtain the access must find a new access site proximal to the "blown" area.
Originally, a peripheral IV was simply a needle that was taped in place and connected to tubing rather than to a syringe; this system is still used for blood donation sets, as the IV access will only be needed for a few minutes and the donor may not move while the needle is in place. Today, hospitals use a safer system in which the catheter is a flexible plastic tube that originally contains a needle to allow it to pierce the skin; the needle is then removed and discarded, while the soft catheter stays in the vein. This method is a variation of the
Seldinger techniqueThe Seldinger technique is a medical procedure to obtain safe access to blood vessels and other hollow organs. It is named after Dr. Sven-Ivar Seldinger , a Swedish radiologist from Mora, Dalarna County, who introduced the procedure in 1953....
. The external portion of the catheter, which is usually taped in place or secured with a self-adhesive dressing, consists of an inch or so of flexible tubing and a locking hub. For centrally placed IV lines, sets and flushes contain a small amount of the anticoagulant
heparinHeparin, a highly-sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule. It can also be used to form an inner anticoagulant surface on various experimental and medical devices such as test tubes and...
to keep the line from clotting off, and frequently are called "heparin locks" or "hep-locks". However, heparin is no longer recommended as a locking solution for peripheral IVs;
salineIn medicine, saline is a general term referring to a sterile solution of sodium chloride in water. It is used for intravenous infusion, rinsing contact lenses, and nasal irrigation. Saline solutions are available in various formulations for different purposes...
is now the solution of choice for a "vac lock".
A peripheral IV cannot be left in the vein indefinitely, because of the risk of insertion-site infection leading to
phlebitisPhlebitis 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. These clots can travel to the lungs, causing pulmonary embolisms which can be...
,
cellulitisCellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters,...
and
sepsisSepsis is a serious medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection.
. The US Centers for Disease Control and PreventionThe Centers for Disease Control and Prevention is a United States federal agency under the Department of Health and Human Services based in Atlanta, Georgia. It works to protect public health and safety by providing information to enhance health decisions, and it promotes health through...
updated their guidelines and now advise the cannula need to be replaced every 96 hours. This was based on studies organised to identify causes of Methicillin-resistant Staphylococcus aureusMethicillin-resistant Staphylococcus aureus is a bacterium responsible for difficult-to-treat infections in humans. It may also be referred to as multidrug-resistant Staphylococcus aureus or oxacillin-resistant Staphylococcus aureus...
MRSA infection in hospitals. In the United Kingdom, the UK Department of health published their finding about risk factors associated with increased MRSA infection, now include intravenous cannula, central venous catheters and urinary catheters as the main factors increasing the risk of spreading antibiotic resistant strain bacteriaAntibiotic resistance is the ability of a microorganism to withstand the effects of antibiotics. It is a specific type of drug resistance. Antibiotic resistance evolves via natural selection acting upon random mutation, but it can also be engineered by applying an evolutionary stress on a population...
in hospitals.
Central IV lines
Central IV linesIn medicine, a central venous catheter is a catheter placed into a large vein in the neck , chest or groin...
flow through a catheter with its tip within a large vein, usually the superior vena cavaThe superior vena cava is a large diameter, yet short vein that carries deoxygenated blood from the upper half of the body to the heart's right atrium....
or inferior vena cavaThe inferior vena cava is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart....
, or within the right atriumIn anatomy, the atrium , sometimes called auricle, refers to a chamber or space. It may be the atrium of the lateral ventricle in the brain or the blood collection chamber of a heart. It has a thin-walled structure that allows blood to return to the heart. There is at least one atrium in animals...
of the heart. This has several advantages over a peripheral IV:
- It can deliver fluids and medications that would be overly irritating to peripheral veins because of their concentration or chemical composition. These include some chemotherapy
Chemotherapy, in its most general sense, is the treatment of disease by chemicals especially by killing micro-organisms or cancerous cells. In popular usage, it refers to antineoplastic drugs used to treat cancer or the combination of these drugs into a cytotoxic standardized treatment regimen...
drugs and total parenteral nutritionParenteral 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...
.
- Medications reach the heart immediately, and are quickly distributed to the rest of the body.
- There is room for multiple parallel compartments (lumen) within the catheter, so that multiple medications can be delivered at once even if they would not be chemically compatible within a single tube.
- Caregivers can measure central venous pressure
Central venous pressure describes the pressure of blood in the thoracic vena cava, 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 into the arterial system....
and other physiological variables through the line.
Central IV lines carry risks of bleeding, infection, gangreneGangrene is a complication of necrosis or cell death characterized by the decay of body tissues, which become black and malodorous. It is caused by infection or ischemia, such as from thrombosis. It is usually the result of critically insufficient blood supply and is often associated with...
, and gas embolism (see Risks below).
GangreneGangrene is a complication of necrosis or cell death characterized by the decay of body tissues, which become black and malodorous. It is caused by infection or ischemia, such as from thrombosis. It is usually the result of critically insufficient blood supply and is often associated with...
is likely if the injection accidentally hits an arteryArteries are blood vessels that carry blood away from the heart. All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.The circulatory system is extremely important for sustaining life...
.
There are several types of central IVs, depending on the route that the catheter takes from the outside of the body to the vein.
Peripherally inserted central catheter
PICC lines are used when intravenous access is required over a prolonged period of time, as in the case of long chemotherapyChemotherapy, in its most general sense, is the treatment of disease by chemicals especially by killing micro-organisms or cancerous cells. In popular usage, it refers to antineoplastic drugs used to treat cancer or the combination of these drugs into a cytotoxic standardized treatment regimen...
regimens, extended antibioticIn common usage, an antibiotic is a substance or compound that kills or inhibits the growth of bacteria...
therapy, or total parenteral nutritionParenteral 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...
.
The PICC line is inserted into a peripheral vein using the Seldinger techniqueThe Seldinger technique is a medical procedure to obtain safe access to blood vessels and other hollow organs. It is named after Dr. Sven-Ivar Seldinger , a Swedish radiologist from Mora, Dalarna County, who introduced the procedure in 1953....
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 feel and estimation; an X-ray then verifies that the tip is in the right place.
A PICC may have two parallel compartments, each with its own external connector (double-lumen), or a single tube and connector (single-lumen). Triple connectors (triple-lumen) catheters and power-injectable PICCs are now available as well. From the outside, a single-lumen PICC resembles a peripheral IV, except that the tubing is slightly wider.
The insertion site must be covered by a larger sterile dressing than would be required for a peripheral IV, due to the higher risk of infection if bacteria travel up the catheter. However, a PICC poses less of a systemic infection risk than other central IVs, because bacteria would have to travel up the entire length of the narrow catheter before spreading through the bloodstream.
The chief advantage of a PICC over other types of central lines is that it is easy to insert, poses a relatively low risk of bleeding, is externally unobtrusive, and can be left in place for months to years for patients who require extended treatment. The chief disadvantage is that it must travel through a relatively small peripheral vein and is therefore limited in diameter, and also somewhat vulnerable to occlusion or damage from movement or squeezing of the arm.
Central venous lines
There are several types of catheters that take a more direct route into central veins. These are collectively called central venous linesIn medicine, a central venous catheter is a catheter placed into a large vein in the neck , chest or groin...
.
In the simplest type of central venous access, a catheter is inserted into a subclavianIn human anatomy, the subclavian veins are two large veins, one on either side of the body. Its diameter is approximately that of the small finger...
, internal jugularThe two internal jugular veins collect the blood from the brain, the superficial parts of the face, and the neck.-Path:The inferior petrosal sinus and the sigmoid sinus join to form each internal jugular vein, and begins in the posterior compartment of the jugular foramen, at the base of the...
, or (less commonly) a femoral veinIn the human body, the femoral vein is a blood vessel that accompanies the femoral artery in the femoral sheath. It begins at the adductor canal and is a continuation of the popliteal vein...
and advanced toward the heart until it reaches the superior vena cava or right atrium. Because all of these veins are larger than peripheral veins, central lines can deliver a higher volume of fluid and can have multiple lumens.
Another type of central line, called a Hickman lineA Hickman line is an intravenous catheter most often used for the administration of chemotherapy or other medications, as well as for the withdrawal of blood for analysis. Some types of Hickman lines are used mainly for the purpose of apheresis or dialysis...
or Broviac catheter, is inserted into the target vein and then "tunneled" under the skin to emerge a short distance away. This reduces the risk of infection, since bacteria from the skin surface are not able to travel directly into the vein; these catheters are also made of materials that resist infection and clotting.
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 however, 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 thrombusA thrombus , or blood clot, is the final product of the blood coagulation step in hemostasis. It is achieved via the aggregation of platelets that form a platelet plug, and the activation of the humoral coagulation system...
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.
Intravenous drip
An intravenous drip is the continuous infusion of fluids, with or without medications, through an IV access device. This may be to correct dehydrationDehydration is defined as excessive loss of body water. It is literally the removal of water from an object. In physiological terms, it entails a relative deficiency of water molecules in relation to other dissolved solutes...
or an electrolyteIn chemistry, an electrolyte is any substance containing free ions that behaves as an electrically conductive medium, usually when in a solution...
imbalance, to deliver medications, or for blood transfusionBlood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. 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...
.
IV fluids
There are two types of fluids that are used for intravenous drips; crystalloids and colloids. Crystalloids are aqueous solutionIn chemistry, a solution is a homogeneous mixture composed of two or more substances. In such a mixture, a solute is dissolved in another substance, known as a solvent. Gases may dissolve in liquids, for example, carbon dioxide or oxygen in water. Liquids may dissolve in other liquids. Gases can...
s of mineral salts or other water-soluble molecules. Colloids contain larger insoluble molecules, such as gelatinGelatin is a translucent, colorless, odorless, brittle, nearly tasteless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing. Substances containing gelatin or functioning...
; bloodBlood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports waste products away from those same cells....
itself is a colloid.
Colloids preserve a high colloid osmotic pressure in the blood, while, on the other hand, this parameter is decreased by crystalloids due to hemodilution. However, there is still controversy to the actual difference in efficacy by this difference. Another difference is that crystalloids generally are much cheaper than colloids.
The most commonly used crystalloid fluid is normal salineIn medicine, saline is a general term referring to a sterile solution of sodium chloride in water. It is used for intravenous infusion, rinsing contact lenses, and nasal irrigation. Saline solutions are available in various formulations for different purposes...
, a solution of sodium chlorideSodium chloride, also known as salt, common salt, table salt, or halite, is an ionic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
at 0.9% concentration, which is close to the concentration in the blood (isotonicThe term isotonic may refer to;* Isotonic for the term associated with muscle contraction* An isotone in nuclear physics* Isotonic solutions, solutions that have equal osmotic pressure, such as the isotonic environment in cell biology...
). Ringer's lactate or Ringer's acetate is another isotonic solution often used for large-volume fluid replacement. A solution of 5% dextrose in water, sometimes called D5W, is often used instead if the patient is at risk for having low blood sugarBlood sugar concentration, or glucose level, refers to the amount of glucose present in the blood of a human or animal. Normally, in mammals the blood glucose level is maintained at a reference range between about 3.6 and 5.8 mM...
or high sodiumSodium is a metallic element with a symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals within "group 1"...
. The choice of fluids may also depend on the chemical properties of the medications being given.
Intravenous fluids must always be sterileSterilization refers to any process that effectively kills or eliminates transmissible agents from a surface, equipment, article of food or medication, or biological culture medium. Sterilization does not, however, remove prions...
.
Composition of common crystalloid solutions
| Solution |
Other Name |
[Na+](mmol/L) |
[Cl-](mmol/L) |
[Glucose](mmol/L) |
[Glucose](mg/dl) |
| D5W |
5% Dextrose |
0 |
0 |
278 |
5000 |
| 2/3D & 1/3S |
3.3% Dextrose / 0.3% saline |
51 |
51 |
185 |
3333 |
| Half-normal saline |
0.45% NaCl |
77 |
77 |
0 |
0 |
| Normal saline |
0.9% NaCl |
154 |
154 |
0 |
0 |
| Ringer's lactate |
Lactated Ringer |
130 |
109 |
0 |
0 |
Ringer's lactate also has 28 mmol/L lactate, 4 mmol/L K+ and 3 mmol/L Ca2+.
Ringer's acetate also has 28 mmol/L acetate, 4 mmol/L K+ and 3 mmol/L Ca2+.
Effect of adding one litre
| Solution |
Change in ECF Extracellular fluid usually denotes all body fluid outside of cells. The remainder is called intracellular fluid.In some animals, including mammals, the extracellular fluid can be divided into two major subcompartments, interstitial fluid and blood plasma...
|
Change in ICF |
| D5W |
333 mL |
667 mL |
| 2/3D & 1/3S |
556 mL |
444 mL |
| Half-normal saline |
667 mL |
333 mL |
| Normal saline |
1000 mL |
0 mL |
| Ringer's lactate |
900 mL |
100 mL |
Infusion equipment
A standard IV infusion set consists of a pre-filled, sterile container (glass bottle, plastic bottle or plastic bag) of fluids with an attached which 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 connectors to allow "piggybacking" of another infusion set onto the same line, e.g., adding a dose of antibiotics to a continuous fluid drip.
An infusion pumpAn 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....
allows precise control over the flow rate and total amount delivered, but 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.
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.
Intermittent infusion
Intermittent infusion is used when a patient requires medications only at certain times, and does not require additional fluid. It can use the same techniques as an intravenous drip (pump or gravity drip), but after the complete dose of medication has been given, the tubing is disconnected from the IV access device. Some medications are also given by IV push, meaning that a syringe is connected to the IV access device and the medication is injected directly (slowly, if it might irritate the vein or cause a too-rapid effect). 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.
Infection
Any break in the skin carries a risk of infection. Although IV insertion is a sterile procedure, skin-dwelling organisms such as Coagulase-negative staphylococcus or Candida albicansCandida albicans is a diploid fungus and a causal agent of opportunistic oral and genital infections in humans. Systemic fungal infections have emerged as important causes of morbidity and mortality in immunocompromised patients...
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 septicemia and can be rapid and life-threatening. An infected central IV poses a higher risk of septicemia, as it can deliver bacteria directly into the central circulation.
Phlebitis
PhlebitisPhlebitis 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. These clots can travel to the lungs, causing pulmonary embolisms which can be...
is irritation of a vein that is not caused by infection, but from 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, the peripheral veins of intravenous drug addicts, and of cancer patients undergoing chemotherapy, become hardened and difficult to access over time.
Infiltration
Infiltration occurs when an IV fluid accidentally enters the surrounding tissue rather than the vein. It is characterized by coolness and pallor to the skin as well as localized swelling or edema. It is usually not painful. It is treated by removing the intravenous access device and elevating the affected limb so that the collected fluids can drain away. Infiltration is one of the most common adverse effects of IV therapy and is usually not serious unless the infiltrated fluid is a medication damaging to the surrounding tissue, in which case the incident is known as extravasation.
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 hypertensionHypertension is a chronic medical condition in which the blood pressure is elevated. It is also referred to as high blood pressure or shortened to HT, HTN or HPN. The word "hypertension", by itself, normally refers to systemic, arterial hypertension.Hypertension can be classified as either...
, heart failure, and pulmonary edemaPulmonary edema , or oedema , is fluid accumulation in the lungs. It leads to impaired gas exchange and may cause respiratory failure. It is due to either failure of the heart to remove fluid from the lung circulation or a direct injury to the lung parenchyma...
.
Electrolyte imbalance
Administering a too-dilute or too-concentrated solution can disrupt the patient's balance of sodiumSodium is a metallic element with a symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals within "group 1"...
, potassiumPotassium is the chemical element with the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash...
, magnesiumMagnesium is a chemical element with the symbol Mg, atomic number 12 and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the earth's crust by mass, although ninth in the Universe as a whole...
, and other electrolyteIn chemistry, an electrolyte is any substance containing free ions that behaves as an electrically conductive medium, usually when in a solution...
s. Hospital patients usually receive blood tests to monitor these levels.
Embolism
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 embolismAn air embolism, or more generally gas embolism, is a physiological condition caused by gas bubbles in a vascular system. The most common context is a human body, in which case it refers to gas bubbles in the bloodstream...
. Peripheral IVs have a low risk of embolism, since large solid masses cannot travel through a narrow catheter, and 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 milliliters are thought to dissolve into the circulation harmlessly. Small volumes do not result in readily detectable symptoms, but ongoing studies hypothesize that these "micro-bubbles" may have some adverse effects. A larger amount of air, if delivered all at once, can cause life-threatening damage to pulmonaryThe lung or pulmonary system is the essential respiration organ in air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located in the chest on either side of the heart...
circulation, 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 heart defect causing a right-to-left shunt is vulnerable to embolism from smaller amounts of air. Fatality by air embolism is vanishingly rare, in part because it is also difficult to diagnose.
Extravasation
ExtravasationExtravasation is the accidental administration of intravenously infused medicinal drugs into the surrounding tissue, either by leakage , or direct exposure...
is the accidental administration of IV infused medicinal drugs into the surrounding tissue which are caustic to these tissues, either by leakage (e.g. because of brittle veins in very elderly patients), or directly (e.g. because the needle has punctured the vein and the infusion goes directly into the arm tissue). This occurs more frequently with chemotherapeutic agents.
See also
- Life support
Life support, in medicine is a broad term that applies to any therapy used to sustain a patients life while they are critically ill or injured. There are many therapies and techniques that may be used by clinicians to achieve the goal of sustaining life...
- Blood transfusion
Blood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. 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 substitutes
Blood substitutes are used to fill fluid volume and/or carry oxygen and other blood gases in the cardiovascular system. Although commonly used, the term is not accurate since human blood performs many important functions which blood substitutes may not...
- Oral rehydration therapy
Oral rehydration therapy is a simple, cheap, and effective treatment for dehydration associated with diarrhea, particularly gastroenteritis, such as that caused by cholera or rotavirus. ORT consists of a solution of salts and sugars which is taken by mouth...
- Bolus (medicine)
In medicine, a bolus is the administration of a medication, drug or other compound that is given to raise its concentration in blood to an effective level...
- Dialysis
In medicine, dialysis is primarily used to provide an artificial replacement for lost kidney function due to renal failure...
- Saline flush
A saline flush is the method of clearing out feeding tubes and intravenous lines of any food, medicine, or other perishable liquids so that they can keep the area of entering clean and sterile...
- Hypodermic needle
A hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body or extract liquids from the body...
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