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Glossary of Children's Hospital Terms


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ICU: Intensive care unit.

Ig (immunoglobulin): Immunoglobulins (abbreviated Ig) are an essential part of the body's immune system.  They attach to foreign substances, such as bacteria and destroy them. There are 5 classes of immunoglobulins: A, D, E, G, and M. 
  • IgA or immunoglobulin A: A major class of immunoglobulins found in serum and external body secretions such as saliva, tears, and sweat as well as in the gastrointestinal, respiratory, and genitourinary tracts.
  • IgD or immunoglobulin D: A class of immunoglobulins found as antibodies on the surface of B cells (B-lymphocytes). Almost nothing is known about the normal function of IgD.
  • IgE or immunoglobulin E: A class that includes the antibodies elicited by an allergic substance (allergen). A person who has an allergy usually has elevated blood levels of IgE.  IgE antibodies attack the invading army of allergens.
  • IgG or immunoglobulin G: A major class including many of the most common antibodies circulating in the blood. Also known as gamma globulin. Intravenous IgG is sometimes given to aid in fighting infections or immune diseases.
  • IgM or immunoglobulin M: A major class of immunoglobulins. IgM includes the antibodies that are produced first in an immune response and are later replaced by other types of antibodies.  Their presence indicates acute or recent infection.
IM or IntraMuscular: An intramuscular (IM) medication is given by needle into the muscle. This is as opposed to a medication that is given by a needle into the skin (intradermal) or just below the skin (subcutaneous) or into a vein (intravenous).
IV or Intravenous: Meaning into a vein. Intravenous (IV) antibiotics are a solution containing antibiotics that is administered directly into the venous circulation via a syringe or intravenous catheter (tube).  IV may also refer to the actual solution that is administered intravenously or to the device used to administer an intravenous solution.
IV pump: The machine that controls the delivery of fluids and medications through an intravenous catheter.
Ileus: Obstruction of the intestine due to it being paralyzed. The paralysis does not need to be complete to cause ileus, but the intestine must be so inactive that it prohibits the passage of food and leads to blockage of the intestine. Ileus commonly follows some types of surgery. It can result also from certain drugs, injuries, and illnesses. Despite the cause, ileus causes constipation and bloating. On listening to the abdomen with a stethoscope, no bowel sounds are heard (because the bowel is inactive). It may also be called paralytic ileus. It is usually a transient problem.
Immune system: The body's system of defenses against disease or allergies. The immune system is primarily composed of white blood cells and antibodies, but includes other agents as well.
Immunosuppressed or Immunocompromised: The state where the body has a reduced ability to adequately fight infections.
Incontinence: Inability to control excretions. Urinary incontinence is inability to keep urine in the bladder. Fecal incontinence is inability to retain feces in the rectum.
Infection: Invasion of any part of the body by germs. Bacteria, viruses, and fungi are the major germs that infect humans.
Infiltrate: To penetrate. If an IV infiltrates, the IV fluid penetrates outside the vein and into the surrounding tissue.
Inflammation: A basic way in which the body reacts to infection, irritation or other injury, the key features being redness, warmth, swelling and pain. Inflammation is now recognized as a type of nonspecific immune response.
Informed consent: The process whereby a patient/parent/legal guardian is given information about a specific surgery or treatment including its intended result and possible complications.  Informed consent must be obtained before the procedure or treatment is done except in an emergency situation.  Where English is not the primary language, Providence Hospital offers a program to provide translators to explain treatments and options.
Infuse: In medicine, an infusion is the therapeutic introduction of a fluid other than blood into a vein.  The infused fluid might, for example, be a saline (salt) solution.
Intake and Output (I & O): An accounting of fluid taken in, lost or secreted.
Intercostal space: The space between any 2 ribs.
Intra-arterially: Meaning inside of an artery.
Intracellular fluid: The fluid normally present inside of each body cell.
Intubation: The process of putting a tube into a hollow organ or passageway, often into the airway. The opposite of intubation is extubation.
Irrigate: To wash out. For example, to clean a wound.
Ischemia: Inadequate blood supply (circulation) to a local area due to blockage of the blood vessels.
Isolation: To keep exposure to a minimum because of possibility of infecting the patient or a patient infecting others.
Isotonic solution: A solution that has the same salt concentration as the normal cells of the body and the blood.  An isotonic beverage (such as Gatorade) may be drunk to replace the fluid and minerals that the body uses during physical activity.