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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
Measures all of the cholesterol in all the lipoprotein
particles.
<
200
200–239
≥
240
Desirable
Borderline high
High
High-Density
Lipoprotein
Cholesterol (HDL-C)
Measures the cholesterol in HDL particles; often called
“good cholesterol” because it removes excess cholesterol
and carries it to the liver for removal.
≤
40
≥
60
Low
High
Low-Density
Lipoprotein
Cholesterol (LDL-C)
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
<
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