++
This chapter outlines commonly ordered blood chemistry, immunology,
and serology tests and other common laboratory investigations. Normal
values and a guide to the diagnosis of common abnormalities are
provided. Additional tests are described in the following chapters:
hematology, Chapter 5; urine studies, Chapter 6; microbiology, Chapter 7; and Blood Gases, Chapter 8. Increased
or decreased values that are not clinically useful usually are not
listed. Because each laboratory has its own set of normal reference
intervals, the normal values given should be used only as a guide.
Unless specified, values reflect normal levels in adults. The method
of collection is included because laboratories have attempted to
standardize collection methods; however, be aware that some labs
may have other collection methods. Blood specimen tubes are listed
in Chapter 13, Table 13–8.
++
Most laboratories offer AMA-recommended “panel” tests,
whereby multiple determinations are performed on a single sample.
Although labs may vary, common chemistry panels include the following:
++
- AMA Electrolyte Panel: Sodium,
potassium, chloride, CO2
- AMA Basic Metabolic Panel: Calcium,
CO2, chloride, creatinine, glucose, potassium, sodium,
BUN
- AMA Comprehensive Metabolic Panel: albumin,
ALT, AST, total bilirubin, calcium, chloride, CO2, creatinine,
glucose, alkaline phosphatase, potassium, total protein, sodium,
BUN
- AMA Renal Function Panel: Albumin,
calcium, CO2, chloride, creatinine, glucose, phosphorus
serum, potassium, sodium, BUN
- AMA Hepatic Function Panel: Total
protein, albumin, total bilirubin, direct bilirubin, alkaline phosphate,
AST, ALT
- AMA Lipid Panel: Cholesterol,
HDL, LDL (calculated from cholesterol and
hydroxycholesterol [HC]), triglycerides
+++
Other Common Panel Tests
++
- Chem-7 Panel/SMA-7: BUN,
creatinine, electrolytes (Na, K, Cl, CO2), glucose
- Health Screen-12/SMA-12: Albumin,
alkaline phosphatase, AST (SGOT), bilirubin (total), calcium, cholesterol,
creatinine, glucose, LDH, phosphate, protein (total), uric acid
- Cardiac Enzymes: CK-MB (if total
CK > 150 IU/L), troponin
++
Every reimbursable laboratory test has an associated CPT code
used for billing transactions. The CPT (Current
Procedural Terminology) system was developed by and is a registered
trademark of the American Medical Association (AMA). CPT codes have
been incorporated as the standard code set for Medicare and Medicaid reimbursement.
They also are used in the Health Insurance Portability and Accountability
Act (HIPAA) and have been adopted by private insurance carriers
and managed care companies.
++
CPT codes are designated for services that are part of “contemporary
medical practice and being performed by many physicians in clinical
practice in multiple locations.” Each of the codes consists
of a five-digit number that is associated with a text descriptor
(eg, 82565, Creatinine; blood).
++
To comply with government regulations as specified by the Centers
for Medicare & Medicaid Services (CMS), clinical pathology laboratories
require physicians who order tests to provide appropriate International Classification of Disease,
Ninth Revision (ICD-9) diagnosis
and procedure codes that in turn indicate which laboratory tests
are reimbursable.
++