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27 Cards in this Set

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What does the test result mean?
A low level of blood sodium means you have hyponatremia, which is usually due to too much sodium loss, too much water intake or retention, or to fluid accumulation in the body (edema). If sodium falls quickly, you may feel weak and fatigued; in severe cases, you may experience confusion or even fall into a coma. When sodium falls slowly, however, there may be no symptoms. That is why sodium levels are often checked even if you don’t have any symptoms.
Hyponatremia is rarely due to decreased sodium intake (deficient dietary intake or deficient sodium in IV fluids). Most commonly, it is due to sodium loss (Addison's disease, diarrhea, excessive sweating, diuretic administration, or kidney disease). In some cases, it is due to increased water (drinking too much water, heart failure, cirrhosis, kidney diseases that cause protein loss [nephrotic syndrome]). In a number of diseases (particularly those involving the brain and the lungs, many kinds of cancer, and with some drugs), your body makes too much anti-diuretic hormone (ADH), causing you to keep too much water in your body.

A high blood sodium level means you have hypernatremia and is almost always due to dehydration without enough water intake. Symptoms include dry mucous membranes, thirst, agitation, restlessness, acting irrationally, and coma or convulsions if levels rise extremely high. In rare cases, hypernatremia may be due to increased salt intake without enough water, Cushing syndrome, or a condition caused by too little ADH, called diabetes insipidus.

Sodium urine concentrations must be evaluated in association with blood levels. Concentrations may mirror blood levels or be the opposite. The body normally excretes excess sodium, so the concentration in the urine may be elevated because it is elevated in the blood. It may also be elevated in the urine when the body is losing too much sodium. In this case, the blood level would be normal to low. If blood sodium levels are low due to insufficient intake, then urine concentrations will also be low.

-Decreased urinary sodium levels may indicate dehydration, congestive heart failure, liver disease, or nephrotic syndrome.
-Increased urinary sodium levels may indicate diuretic use or Addison's disease.

Sodium levels are often evaluated in relation to other electrolytes and can be used to calculate anion gap in order to identify the cause of acidosis.

What does the test result mean?
Increased potassium levels indicate hyperkalemia. Increased levels may also indicate the following health conditions:
acute or chronic kidney failure
Addison's disease
hypoaldosteronism (see Aldosterone)
injury to tissue
excessive dietary potassium intake (for example, fruits are particularly high in potassium, so excessive intake of fruits or juices may contribute to high potassium)
excessive intravenous potassium intake
Certain drugs can also cause hyperkalemia in a small percent of patients. Among them are non-steroidal anti-inflammatory drugs (such as Advil, Motrin, and Nuprin); beta blockers (such as propanolol and atenolol), angiotensin-converting enzyme inhibitors (such as captopril, enalapril, and lisinopril), and potassium-sparing diuretics (such as triamterene, amiloride, and spironolactone).

Decreased levels of potassium indicate hypokalemia. Decreased levels may occur in a number of conditions, particularly:

Hyperaldosteronism (see Aldosterone)
deficient potassium intake (rare)
as a complication of acetaminophen overdose
In diabetes, your potassium may fall after you take insulin, particularly if your diabetes had been out of control for a while. Low potassium is commonly due to "water pills" (diuretics); if you are taking these, your doctor will check your potassium level regularly.

Additionally, certain drugs such as corticosteroids, beta-adrenergic agonists such as isoproterenol, alpha-adrenergic antagonists such as clonidine, antibiotics such as gentamicin and carbenicillin, and the antifungal agent amphotericin B can cause loss of potassium.

High Total Calcium - Hypercalcemia

Two of the more common causes of hypercalcemia are:

Hyperparathyroidism, an increase in parathyroid gland function: This condition is usually caused by a benign tumor of the parathyroid gland. This form of hypercalcemia is usually mild and can be present for many years before being noticed.
Cancer: Cancer can cause hypercalcemia when it spreads to the bones and causes the release of calcium from the bone into the blood or when a cancer produces a hormone similar to PTH, resulting in increased calcium levels.
Some other causes of hypercalcemia include:

Prolonged immobilization
Excess Vitamin D intake
Kidney transplant
Low Total Calcium - Hypocalcemia

The most common cause of low total calcium is:

Low blood protein levels, especially a low level of albumin. In this condition, only the bound calcium is low. Ionized calcium remains normal and calcium metabolism is being regulated appropriately.
Some other causes of hypocalcemia include:

Underactive parathyroid gland (hypoparathyroidism)
Inherited resistance to the effects of parathyroid hormone
Extreme deficiency in dietary calcium
Decreased levels of vitamin D
Magnesium deficiency
Increased levels of phosphorus
Acute inflammation of the pancreas (pancreatitis)
Renal failure
Urinary calcium levels may be affected by the same conditions and diseases that affect blood levels (listed above). In cases of suspected kidney stones, the cause may be due a high level of calcium in the urine. Hypercalciuria is an inherited disordered that can lead to kidney stones. Hypercalcuria causes increased calcium in the urine, which leads to the formation of crystals in the kidneys and other parts of the urinary tract. It may be the cause of kidney stones in about half of affected people.

What does the test result mean?

Low levels of magnesium may indicate that a person is not consuming or absorbing enough or is excreting too much magnesium. Deficiencies are typically seen with:
Low dietary intake (seen in the elderly, malnourished, and with alcoholism)
Gastrointestinal disorders (such as Crohn's disease)
Uncontrolled diabetes
Long-term diuretic use
Prolonged diarrhea
Post surgery
Severe burns
Toxemia of pregnancy
Increased levels of magnesium are rarely due to dietary sources but are usually the result of an excretion problem or excessive supplementation. Increased levels are seen in:

Kidney failure
Diabetic acidosis (when first seen)
Addison's disease
Use of magnesium-containing antacids or laxatives

What does the test result mean?

Low levels of phosphorus (hypophosphatemia) may be due to or associated with:
Hypercalcemia, especially due to hyperparathyroidism
Overuse of diuretics
Severe burns
Diabetic ketoacidosis (after treatment)
Chronic antacid use
Rickets and osteomalacia (due to Vitamin D deficiencies)
Higher than normal levels of phosphorus (hyperphosphatemia) may be due to or associated with:

Kidney failure
Diabetic ketoacidosis (when first seen)
Increased dietary intake (phosphate supplementation)

What does the test result mean?
Increased BUN levels suggest impaired kidney function. This may be due to acute or chronic kidney disease, damage, or failure. It may also be due to a condition that results in decreased blood flow to the kidneys, such as congestive heart failure, shock, stress, recent heart attack, or severe burns, to conditions that cause obstruction of urine flow, or to dehydration.
BUN concentrations may be elevated when there is excessive protein breakdown (catabolism), significantly increased protein in the diet, or gastrointestinal bleeding (because of the proteins present in the blood).

Low BUN levels are not common and are not usually a cause for concern. They may be seen in severe liver disease, malnutrition, and sometimes when a patient is overhydrated (too much fluid volume), but the BUN test is not usually used to diagnose or monitor these conditions.

Both decreased and increased BUN concentrations may be seen during a normal pregnancy.

If one kidney is fully functional, BUN concentrations may be normal even when significant dysfunction is present in the other kidney.

What does the test result mean?
Increased creatinine levels in the blood suggest diseases or conditions that affect kidney function. These can include:
Damage to or swelling of blood vessels in the kidneys (glomerulonephritis) caused by, for example, infection or autoimmune diseases
Bacterial infection of the kidneys (pyelonephritis)
Death of cells in the kidneys’ small tubes (acute tubular necrosis) caused, for example, by drugs or toxins
Prostate disease, kidney stone, or other causes of urinary tract obstruction
Reduced blood flow to the kidney due to shock, dehydration, congestive heart failure, atherosclerosis, or complications of diabetes
Creatinine blood levels can also increase temporarily as a result of muscle injury and are generally slightly lower during pregnancy.

Low blood levels of creatinine are not common, but they are also not usually a cause for concern. They can be seen with conditions that result in decreased muscle mass.

Levels of 24-hour urine creatinine are evaluated with blood levels as part of a creatinine clearance test.

Random urine creatinine levels have no standard reference ranges. They are usually used with other tests to reference levels of other substances measured in the urine. Some examples include the microalbumin test and urine protein test.

What is being tested?
Glucose is a simple sugar that serves as the main source of energy for the body. The carbohydrates we eat are broken down into glucose (and a few other simple sugars), absorbed by the small intestine, and circulated throughout the body. Most of the body's cells require glucose for energy production; brain and nervous system cells not only rely on glucose for energy, they can only function when glucose levels in the blood remain above a certain level.
The body's use of glucose hinges on the availability of insulin, a hormone produced by the pancreas. Insulin acts as a traffic director, transporting glucose into the body's cells, directing the body to store excess energy as glycogen for short-term storage and/or as triglycerides in adipose (fat) cells. We cannot live without glucose or insulin, and they must be in balance.

Normally, blood glucose levels rise slightly after a meal, and insulin is secreted to lower them, with the amount of insulin released matched up with the size and content of the meal. If blood glucose levels drop too low, such as might occur in between meals or after a strenuous workout, glucagon (another pancreatic hormone) is secreted to tell the liver to turn some glycogen back into glucose, raising the blood glucose levels. If the glucose/insulin feedback mechanism is working properly, the amount of glucose in the blood remains fairly stable. If the balance is disrupted and glucose levels in the blood rise, then the body tries to restore the balance, both by increasing insulin production and by excreting glucose in the urine.

Severe, acute hyperglycemia or hypoglycemia can be life-threatening, causing organ failure, brain damage, coma, and, in extreme cases, death. Chronically high blood glucose levels can cause progressive damage to body organs such as the kidneys, eyes, heart and blood vessels, and nerves. Chronic hypoglycemia can lead to brain and nerve damage.

Some women may develop hyperglycemia during pregnancy, which is termed gestational diabetes. If untreated, this can cause these mothers to give birth to large babies who may have low glucose levels. Women who have had gestational diabetes may or may not go on to develop diabetes.

What does the test mean?
For monitoring glucose control, A1c is currently reported as a percentage, and it is recommended that diabetics aim to keep their A1c below 7%. The report for your A1c test also may include an estimated Average Glucose (eAG), which is a calculated result based on your A1c levels. The purpose of reporting eAG is to help you relate your A1c results to your everyday glucose monitoring levels. The formula for eAG converts percentage A1c to units of mg/dL or mmol/L so that you can compare it to your glucose levels from home monitoring systems or laboratory tests.
It should be noted that the eAG is still an evaluation of your glucose over the last couple of months. It will not match up exactly to any one daily glucose test result. The American Diabetes Association has adopted this calculation and provides a calculator and information on the eAG on their web site.

The closer a diabetic can keep their A1c to 6% without experiencing excessive hypoglycemia, the better their diabetes is in control. As the A1c and eAG increase, so does the risk of complications.

In screening and diagnosis, some results that may be seen include:

A nondiabetic person will have an A1c result between 4% and 6%.
Diabetes: A1c level is 6.5% (47 mmol/mol) or higher.
Pre-diabetes (increased risk of developing diabetes in the future): A1c is 5.7% - 6.4% (39 - 46 mmol/mol)

What does the test result mean?

The results indicate the percentage of each type of white blood cell that is present.
Neutrophils can increase in response to bacterial infection or inflammatory disease. Severe elevations in neutrophils may be caused by various bone marrow disorders, such as chronic myelogenous leukemia. Decreased neutrophil levels may be the result of severe infection or other conditions, such as responses to various medications, particularly chemotherapy.

Eosinophils can increase in response to allergic disorders, inflammation of the skin, and parasitic infections. They can also increase in response to some infections or to various bone marrow disorders. Decreased levels of eosinophils can occur as a result of infection.

Basophils can increase in cases of leukemia, chronic inflammation, the presence of a hypersensitivity reaction to food, or radiation therapy.

Lymphocytes can increase in cases of viral infection, leukemia, cancer of the bone marrow, or radiation therapy. Decreased lymphocyte levels can indicate diseases that affect the immune system, such as lupus, and the later stages of HIV infection.

Monocyte levels can increase in response to infection of all kinds as well as to inflammatory disorders. Monocyte counts are also increased in certain malignant disorders, including leukemia. Decreased monocyte levels can indicate bone marrow injury or failure and some forms of leukemia.

Since percentages might be misleading in some patients, absolute values of the various types of WBCs can also be reported, such as the absolute neutrophil count (ANC), also known as the absolute granulocyte count or AGC. Absolute values are calculated by multiplying the number of WBCs by the percentage of each type of white cell and can aid in diagnosing illness and monitoring therapy.

What does the test result mean?
Normal values in an adult are 12 to 18 grams per deciliter (100 milliliters) of blood. Above-normal hemoglobin levels may be the result of:
excess production of red blood cells in the bone marrow,
severe lung disease, or
several other conditions.
Below-normal hemoglobin levels may lead to anemia that can be the result of:

iron deficiency or other deficiencies, such as B12 and folate,
inherited hemoglobin defects, such as sickle cell anemia or thalassemias,
other inherited conditions, such as enzyme defects,
cirrhosis of the liver,
excessive bleeding,
excessive destruction of red blood cells,
kidney disease,
other chronic illnesses,
bone marrow failure or aplastic anemia, or
cancers that affect the bone marrow.

What does the test result mean?

Decreased hematocrit indicates anemia, such as that caused by iron deficiency or other deficiencies. Further testing may be necessary to determine the exact cause of the anemia.
Other conditions that can result in a low hematocrit include vitamin or mineral deficiencies, recent bleeding, cirrhosis of the liver, and malignancies.

The most common cause of increased hematocrit is dehydration, and with adequate fluid intake, the hematocrit returns to normal. However, it may reflect a condition called polycythemia vera—that is, when a person has more than the normal number of red blood cells. This can be due to a problem with the bone marrow or, more commonly, as compensation for inadequate lung function (the bone marrow manufactures more red blood cells in order to carry enough oxygen throughout your body). Anytime a hematocrit is persistently high, the cause should be determined in consultation with a doctor.

With regard to transfusions, this is normally not considered for otherwise healthy persons as long as the hemoglobin level is above 8 grams per deciliter or the hematocrit is above 24%.

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Is there anything else I should know?
Pregnancy usually causes slightly decreased hematocrit values due to extra fluid in the blood.
Living at high altitudes causes increased hematocrit values—this is your body’s response to the decreased oxygen available at these heights.

What does the test result mean?
In an adult, a normal count is about 150,000 to 450,000 platelets per microliter of blood.
If platelet levels fall below 20,000 per microliter, spontaneous bleeding may occur and is considered a life-threatening risk. Patients who have a bone marrow disease, such as leukemia or another cancer in the bone marrow, often experience excessive bleeding due to a significantly decreased number of platelets (thrombocytopenia). As the number of cancer cells increases in the bone marrow, normal bone marrow cells are crowded out, resulting in fewer platelet-producing cells.

Low number of platelets may be seen in some patients with long-term bleeding problems (e.g., chronic bleeding stomach ulcers), thus reducing the supply of platelets. Decreased platelet counts may also be seen in patients with Gram-negative sepsis.

Individuals with an autoimmune disorder (such as lupus or idiopathic thrombocytopenia purpura (ITP), where the body’s immune system creates antibodies that attack its own organs) can cause the destruction of platelets.

Certain drugs, such as acetaminophen, quinidine, sulfa drugs, digoxin, vancomycin, valium, and nitroglycerine, are just a few that have been associated with drug-induced decreased platelet counts. Patients undergoing chemotherapy or radiation therapy may also have a decreased platelet count. Up to 5% of pregnant women may experience thrombocytopenia at term.

Platelet consumption may be observed in renal diseases. Thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are seen in renal failure and can result in fewer circulating platelets in the blood. Similarly, a condition known as splenic sequestration, where platelets pool within the spleen, can also cause a platelet decrease.

More commonly (up to 1% of the population), easy bruising or bleeding may be due to an inherited disease called von Willebrand’s disease. While the platelets may be normal in number, their ability to stick together is impaired due to a decrease in von Willebrand's factor, a protein needed to initiate the clotting process. Many cases may go undiagnosed due to the mild nature of the disease. Many cases are discovered when a patient has to have surgery or a tooth extraction or when delivering a baby. However, some cases are more severe and can be aggravated by use of certain drugs, resulting in a life-threatening situation.

Increased platelet counts (thrombocytosis) may be seen in individuals who show no significant medical problems, while others may have a more significant blood problem called myeloproliferative disorder. Some, although they have an increased number of platelets, may have a tendency to bleed due to the lack of stickiness of the platelets; in others, the platelets retain their stickiness but, because they are increased in number, tend to stick to each other, forming clumps that can block a blood vessel and cause damage, including death (thromboembolism).

Is there anything else I should know?
Living in high altitudes, strenuous exercise, and being post partum may cause increased platelet levels. Drugs that may cause increased platelet levels include estrogen and oral contraceptives.
Decreased levels may be seen in women before menstruation.

Other inherited disorders caused by defective platelets or decreased/absent proteins that activate the platelets include Glanzmann's Thrombasthenia, Bernard-Soulier disease, Chediak-Higashi syndrome, Wiskott-Aldrich syndrome, May-Hegglin syndrome, and Down syndrome. The occurrence of these genetic abnormalities, however, is relatively rare.
4.2-6.1 mil
35 to 45
2-3 (therapeutic)
40-80 sec
45 (55 women)
100 or less if high risk
1, toxic at 2

What does the test result mean?
The therapeutic range for digoxin has been established over time as 0.5-2.0 ng/ml for those being treated for heart failure. Several new studies suggest a more narrow range, 0.5-1.0 ng/ml, may be appropriate for some people. The recommended range for someone with arrhythmia is 1.5-2.0 ng/ml. Most people find that their symptoms improve when their digoxin levels are within these ranges.
It is important to note that each person's response to medications is individual and other factors such as kidney function or concurrent medications may be involved. If someone's symptoms do not improve or if the person is experiencing side effects, then the doctor may need to adjust the digoxin dose up or down according to that person's needs.

If results do not fall within the therapeutic range but the person tested is not experiencing symptoms, then the doctor will evaluate the case and decide if it is necessary to adjust the person's dose. Whether or not the dose needs to be adjusted, the doctor may order additional digoxin tests to determine the resulting blood level.

Is there anything else I should know?
Several prescribed and over-the-counter drugs can affect the level and effectiveness of digoxin. It is important for those taking digoxin to tell their doctor about all medications and supplements they are taking and to notify the doctor when there are any changes in medication.
Digoxin is primarily cleared from your system by the kidneys. When someone has kidney problems, their doctor may want to monitor kidney function and blood potassium levels since kidney dysfunction and low levels of potassium can result in symptoms of digoxin toxicity.

In cases where toxic levels of digoxin are found, antidigoxin antisera may be administered to reverse the effects of the drug.
1, toxic at 2
10-20, toxic at 20
toxic at 20
toxic at 200