Page 123 - Critical Care Nursing Demystified

108 CRITICAL CARE NURSING DeMYSTIFIED

tissue is produced within the heart during an MI. The production of WBCs sur-
rounding the pericardial sac increases the likelihood of pericarditis in an MI.

NURSING ALERT

Signs and symptoms of both local and systemic infections must be explored and
monitored by the nurse in instances of elevated WBCs.

Laboratory Tools: Cholesterol Levels

The term hyperlipidemia is a broad term used to signify high plasma concentrations
of cholesterol and triglycerides in the bloodstream. These are used to evaluate a
patient’s risk for developing atherosclerosis and coronary heart disease. Cholesterol,
produced by the liver, is a lipid or fatty substance that is stored in cell membranes.

Cholesterol, HDL and LDL
Excess amounts of greater than 200 mg/dL is a precursor to the progression of
atherosclerosis. About 20% of cholesterol is HDL, or high-density lipoprotein.
HDL is the good or “HAPPY” cholesterol, because it removes unwanted cho-
lesterol from body cells. LDL, or low-density lipoprotein, is the “BAD” or Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
“LOUSY” cholesterol, because it TRANSPORTS cholesterol to the cells, where
it remains waiting to cause trouble unless it is removed by the “GOOD” or
“HAPPY” cholesterol. The desirable cholesterol level for adults is 130 mg/dL.

Triglycerides
Triglycerides are the most abundant group of lipids and are natural fats and oils
obtained from animal fats and vegetable oils. Triglycerides are useful for energy;
however, excesses are stored in the body as adipose tissue. Acceptable normal
adult triglyceride levels are 40 to 150 mg/dL.

Laboratory Tools: Cardiac Enzymes (Markers)

Isoenzymes
In times of tissue damage, certain enzymes or proteins that are found in mul-
tiple organ systems are released. Specific to the heart are cardiac enzymes,
which are released from damaged myocardial tissue cells and include

Creatine phophokinase (CPK), also known as CK or creatine kinase. When
broken down into component parts, the result yields isoenzymes that provide
diagnostic information specific to cardiac disease. CPK is composed of three
isoenzymes or subunits found in varying amounts in muscle and brain tissue.