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Glossary of Children's Hospital Terms


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LFT’s or Liver Function Tests: are measurements from blood samples that reveal how well the liver is working.

L.O.C.: Loss of consciousness, level of consciousness.
LOS: Length of stay.
LP or Lumbar Puncture: A lumbar puncture is a procedure whereby spinal fluid is removed from the spinal canal for the purpose of diagnostic testing. Other names for a lumbar puncture (an LP) include spinal tap, and spinal puncture.  An LP can also be done for therapeutic purposes, namely as a way of administering antibiotics, cancer drugs, or anesthetic agents into the spinal canal.
Labile: Unstable, unsteady or changing.
Laceration: A cut.
Lactic acidosis: Acidosis due to the buildup of lactic acid (from glucose) when it is created faster than it can be metabolized. The signs are unusually deep and rapid breathing, vomiting, and abdominal pain. It can occur in out-of-control diabetes, shock, hypoxia, or anoxia.
Lactose intolerance: Inability to digest lactose, a component of milk and most other dairy products. Lactose is sometimes also used as an ingredient in other foods, so those with a lactase deficiency should check labels carefully.  The most common symptoms of lactase deficiency are diarrhea, bloating, and gas.
Laparoscopy: A type of surgery in which a small incision (cut) is made in the abdominal wall through which an instrument (a laparoscope) is placed to permit structures within the abdomen and pelvis to be seen. Tubes, probes, and other instruments can be introduced through the same opening. In this way, a number of surgical procedures can be performed without the need for a large surgical incision.
Laparotomy: An operation to open the abdomen.
Laryngoscope Blade:  a flexible lighted instrument used to look at the inside of the larynx (the voice box). The laryngoscope is inserted through the mouth.
Lavage: Washing out. For example, a gastric lavage is washing out the stomach to remove drugs or poisons.
Laxative: Something that loosens the bowels. Used to combat constipation.
Left ventricular failure: Refers to the condition in which the left ventricle or main pumping chamber of the heart is weakened, stiff, or otherwise unable to function at full capacity. Right ventricular failure also occurs.
Lesion:  A lesion can be almost any abnormality involving any tissue or organ due to any disease or any injury.  There are, not surprisingly, many types of lesions and ways of classifying and describing them.
Lethargy: Abnormal drowsiness, stupor.
Leukemia: A cancer of the bone marrow and blood that is characterized by the abnormal growth of white blood cells.
Leukocyte: A type of white blood cell.
Lower GI series: A series of x-rays of the colon and rectum that is taken after the patient is given a barium enema. (Barium is a white, chalky substance that outlines the colon and rectum on the x-ray).
Lung contusion: A bruise in the lung caused by an injury to the chest.
Lymphadenopathy: Abnormally enlarged lymph nodes. Commonly called "swollen glands."
Lymphocytes: A small white blood cell (leukocyte) that plays a large role in defending the body against disease.  Lymphocytes are responsible for immune responses. There are two main types of lymphocytes: B-cells and T-cells. The B-cells make antibodies that attack bacteria and toxins while the T-cells attack body cells themselves when they have been taken over by viruses or have become cancerous. Lymphocytes secrete products (lymphokines) that affect the functional activities of many other types of cells and are often present at sites of chronic inflammation.
Lymph nodes: Small, bean-shaped organs located throughout the lymphatic system. The lymph nodes store special cells that can trap cancer cells or bacteria that are traveling through the body in lymph fluid. Also called lymph glands.
Lysis: Destruction. Hemolysis (hemo-lysis) is the destruction of red blood cells with the release of hemoglobin; bacteriolysis (bacterio-lysis) is the destruction of bacteria.