Lipp Vis Nursing ChaptLWBK1630_C02_p013-068

Chapter 2 • Cardiovascular Care  15

TESTS

SERUM STUDIES Electrolytes • Potassium level—3.5 to 5.0 mEq/L • Excessive levels can lead to cardiac depression, dysrhythmias, and cardiac arrest • Calcium level—8.2 to 10.3 mEq/dL • Increased levels can cause shortening of the QT interval, bradycardia, and heart block • Low levels result from loop diuretics. Clinical manifestations include cardiac changes such as prolonged ST and QT intervals, and CHF • Magnesium level—1.3 to 2.1 mg/dL • Decreased levels can cause cardiac dysrhythmias: ventricular fibrillation (VF), torsades de pointes • Excessive levels can lead to bradycardia and conduction system blocks

• Sodium level—135 to 145 mEq/L • Etiology of low levels include CHF, diuretic therapy; clinical manifestations include peripheral and pulmonary edema • Chloride level—97 to 107 mEq/L • Low levels caused by diuretics • Etiology of high levels include CHF • Carbon dioxide level—23 to 29 mEq/L • Reduced by thiazide diuretics

Lipid Profile

Test

Measures

Level (mg/dL)

Classification

Total Cholesterol

< 200 200–239 ≥ 240

Measures all of the cholesterol in all the lipoprotein particles.

Desirable Borderline high High

High-Density Lipoprotein Cholesterol (HDL-C) Low-Density Lipoprotein Cholesterol (LDL-C)

≤ 40 ≥ 60

Measures the cholesterol in HDL particles; often called “good cholesterol” because it removes excess cholesterol and carries it to the liver for removal. Calculates the cholesterol in LDL particles; often called “bad cholesterol” because it deposits excess cholesterol in walls of blood vessels, which can contribute to atherosclerosis. Usually, the amount of LDL-C is calculated using the results of total cholesterol, HDL-C, and triglycerides

Low High

< 100 100–129 130–159 160–189 ≥ 190

Optimal Near optimal/above optimal Borderline high High Very high

Triglycerides

Measures all the triglycerides in all the lipoprotein particles; most is in the very low-density lipoproteins (VLDLs).

Less than 150 150–199 200–499 >500

Normal Borderline high High Very high