Lab Values Cheat Sheet
ELEMENTS
Calcium
Description
- Calcium is a cation absorbed into the bloodstreamfromdietary sources and functions in bone formation, nerve impulse transmission, and contraction ofmyocardial and skeletal muscles.
- Calcium aids in blood clotting by converting prothrombin to thrombin.
Lab Value:
8.6 to 10 mg/dL
Nursing considerations
- Instruct the client to eat a diet with a normal calcium level (800 mg/day) for 3 days before the test.
- Instruct the client that fasting may be required for 8 hours before the test.
Magnesium
Description
- Magnesium is used as an index to determine metabolic activity and renal function.
- Magnesium is needed in the blood-clotting mechanism, regulates neuromuscular activity, acts as a cofactor that modifies the activity of many enzymes, and has an effect on the metabolism of calcium.
Lab Value:
1.6 to 2.6 mg/dL
Nursing considerations
- Prolonged use of magnesium products causes increased serum levels.
- Long-term parenteral nutrition therapy or excessive loss of body fluids may decrease serumlevels.
Phosphorus
Description
- Phosphorus is important in bone formation, energy storage and release, urinary acid-base buffering, and carbohydrate metabolism.
- Phosphorus is absorbed from food and is excreted by the kidneys.
- High concentrations of phosphorus are stored in bone and skeletal muscle.
Lab Value:
2.7 to 4.5 mg/dL
Nursing considerations:
Instruct the client to fast before the test.