Understanding Hemolytic Uremic Syndrome Medical Terms

This material was originally written by Barb Michelson, a mother whose daughter had E. coli O157:H7 and Hemolytic Uremic Syndrome in 1993. Michelson "wanted to provide information to parents that we searched for but couldn't find when our daughter was in the acute phase of illness with HUS. It has since been amended and updated.

A note from the author: E. coli O157:H7 and Hemolytic Uremic Syndrome. These terms sounded like a foreign language to us when our daughter first became ill. As parents who were suddenly thrust into emotional turmoil, my husband and I knew we needed to understand the language used in the world of medicine. We found no such resources available to parents so we decided to assemble this glossary. This probably will not cover every term you may need to know but hopefully it will help in some way to make things a little more understandable through this difficult and confusing time.

GLOSSARY

Anemia-a deficiency of red blood cells, the oxygen-carrying component of blood.

Anuric (oligoanuric)-(adjective) the state of producing no urine.

Anuria- (noun) no urine.

Arrhythmia-(noun) an abnormal heart rhythm. The result of abnormal electrical activity or electrical conduction in the heart. May be too fast, too slow, or irregular.

Biliary- (adjective) having to do with the liver or bile ducts.

Bradycardia- (noun) disease of heart muscle.

BUN (blood urea nitrogen)- blood work that measures the blood's content of urea. When you eat protein your blood carries some of it to your cells and what?s left over is a waste called urea (which contains nitrogen). Healthy kidneys get rid of urea in the urine and when the kidneys fail, urea stays in the blood. So, the BUN test is used primarily to evaluate renal (kidney) function by measuring the urea. It may also indicate liver disease or dehydration. In HUS, BUN level rises well above normal, indicating that kidneys are not filtering the blood properly.

Cardiomyopathy- (noun) a disease of heart muscle

CBC (complete blood count)- a series of tests in which the numbers of red blood cells, white blood cells and platelets in a given volume of blood are counted. CBC also measures hemoglobin content and packed cell volume (hematocrit) of red blood cells, assesses the size and shape of the red blood cells (blood smear), and determines the types and percentages of white blood cells. Components of the complete blood count (hemoglobin, hematocrit, white blood cells, platelets, etc.) can also be tested separately when a doctor wants to monitor a specific condition.

Chem 10 or 20- a battery of chemical tests (10 tests in a Chem 10 or 20 tests in a Chem 20) performed on serum (portion of blood without cells). It is usually performed with a CBC to test for electrolytes, creatinine, BUN, etc.

CNS (Central Nervous System)- The brain and spinal cord. In HUS, central nervous system involvement means that the brain has become involved.

Coagulopathy- (verb) the alteration of the mechanism that leads to normal clotting of the blood; may result in too much or too little clotting.

Colitis- (noun) an inflammation of the colon; the usual symptoms are diarrhea, sometimes with blood and mucus, and lower abdominal pain.

Creatinine-(noun) another waste product (from muscle activity) found in the bloodstream that is excreted in urine. Like BUN, creatinine is removed by healthy kidneys. In HUS, the creatinine rises well above normal, indicating kidneys are not filtering the blood properly.

Escherichia coli- (E. coli) a normal bacterial flora in the intestines of many animals, including humans. Normally E. coli serves a useful function in the body by suppressing the growth of harmful bacterial species and by synthesizing essential vitamins. There are pathogenic E. coli strains that cause human illness.

E. coli O157:H7- a pathogenic strain of E. coli rarely found in humans which produces a toxin that can cause severe damage to the lining of the intestine, the blood vessels and to blood cells.

EHEC (enterohemmorhagic E. coli)- (noun) E. coli bacteria which cause gastrointestinal bleeding most often by producing a blood poison (verotoxin).

Encephalitis- (noun) an inflammation of the brain.

Enteric- (adjective) of, relating to, or being within the intestine.

Epithelial cells- (noun) the cells which border tissues exposed to the environment such as the intestinal tract.

Fibrin- (noun) the final product of the process of coagulation; a fibrin links of with similar molecules to make a fibrous meshwork that forms the basis of a bloodclot.

Fulminant presentation- a sudden, severe onset of symptoms.

Gastroenterology- the study of the stomach and intestine and their diseases.

Glomeruli- (noun) a network of blood capillaries contained within the end of a nephron, the site of primary filtration of blood waste products in the kidneys.

Glomerular filtration- (noun) the action provided by the glomeruli in the kidneys.

GFR (Glomerular Filtration Rate)- a measurement of how well the kidneys are filtering waste products and is a formula that is based on a patient's weight, gender, and race as well as on the BUN, creatinine, and serum albumin tests.

Heart failure- (noun) the inability of the heart to perform all the work needed for formal circulation.

Hematocrit- (Hct) the percentage of your blood that is made up of red blood cells.

Hemoglogin- (Hgb) the oxygen-carrying protein that gives your blood its red color.

Hemostasis- (noun) the control of bleeding caused by two integrated processes, the formation of the platelet plug, and the formation of the blood clot.

Hemoturia- (noun) blood in the urine.

Hemolytic Anemia-anemia that results from destruction of red blood cells.

Hemolytic Uremic Syndrome- A disorder marked by renal (kidney) failure, hemolytic anemia (breakdown of red blood cells), platelet deficiency, coagulation(clotting) defects, and variable neurologic (brain) malfunction.

Heparin- (noun) a naturally occurring substance which is a powerful short acting anti-coagulant (prevents blood clotting); is essential for the performance of open heart surgery.

Hypertension- (noun) high blood pressure; hypertension is symptomless until the symptoms of its complications, such as strokes, heart failure or kidney failure, develop.

Infarction- (noun) the death of some tissue, most often the result of inadequate blood supply caused by a blood clot.

Ischemia- (noun) an inadequate blood supply caused by constriction or blockage of blood vessels supplying it.

Lysis- (noun) the destruction of cells by damage or rupture of the cell membrane.

Microangiopathy- (noun) damage to the walls of the smallest blood vessels.

Motility- (noun) movement, as in the movement of food or waste through the gastrointestinal tract.

Necrosis- (noun) the death of tissue/cells, caused by disease, injury or interference of blood supply.

Nephrology-the specialty of medicine dealing with the kidneys.

Platelets (thrombocytes)- the tiny blood cells that initiate blood clotting. Platelets are necessary to form clotting in a healthy person. In HUS, platelets form into tiny clots in the bloodstream, thereby dramatically reducing platelets available for normal clotting and leaving the patient susceptible to excessive internal bleeding.

Platelet microthrombi-(noun) tiny blood clots.

Proteinuria- (noun) the presence of protein in the urine; may indicate damage to or disease of kidneys.

Red Blood Cells (RBCs)- Red blood cells carry oxygen to all parts of the body. In HUS, red blood cells are shredded faster than the body can replace them, so the body struggles to get oxygen to all necessary parts.

Renal- pertaining to the kidneys.

Serum albumin- is the amount of protein in the fluid part of your blood which is also a measurement of your general nutrition

Sequelae- (noun) consequences, symptoms

Thrombocytopenia- (noun) a reduction of the number of platelets in the blood.

Thrombosis (thrombi, microthrombi)-(noun) blood clot(s).

Urea- one of the nitrogenous waste products of protein metabolism. Urea is formed in the liver as the end product of protein metabolism. (see BUN)

Verotoxin- (noun) a poisonous molecule that damages or attacks the blood.

VTEC (verotoxin-producing E. coli)- (noun) an E. coli that puts a poison into the bloodstream and thereby injures blood.

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A Special Note to Parents: While your child is hospitalized with E. coli and/or Hemolytic Uremic Syndrome, focus on your child and information your doctors are sharing. Ask questions, and ask them more than once if needed. The medical team will help you comprehend the things you need to know.

Take care of yourselves through this stressful time. You can give the best care to your child only if you are rested and healthy.