Interpreting and Correlating Abnormal Laboratory Values : Cardiac Function Tests

Diagnosis of Myocardial Infarction (MI) and Acute Coronary Syndrome

Fig. Getting MI attack

Since acute MI (AMI) requires rapid and accurate diagnosis, especially now that new treatment options with thrombolytic agents are available, the clinical laboratory has been called upon to provide serum diagnostic tests that can make this diagnosis at an early stage. Until recently, laboratory diagnosis was based on serial determinations of the MB fraction of creatine phosphokinase (CK-MB); confirmation of the diagnosis was provided by the so-called ‘flipped ratio’ of the isozymes of lactate dehydrogenase (LD) 24-36 hours after the initial acute event and/or by observation of the characteristic time courses for elevations of the three enzymes, CK, aspartate aminotransferase (AST) and LD.

Interpreting and Correlating Abnormal Laboratory Values : Liver Function Tests

The most common liver test abnormalities can be summarized to a set of six conditions as in Table 1. The principles for these patterns are explained as follows.

1.

All acute injuries and/or necrotic lesions in the liver primarily cause a marked rise in the levels of the aminotransferases, aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Cell injury and necrosis also cause the rise of other enzymes such as lactate dehydrogenase (LD). These include acute hepatitis

Interpreting and Correlating Abnormal Laboratory Values : Electrolyte Abnormalities

Electrolyte Abnormalities

Hyponatremia

The four most common causes of hyponatremia are given in Table 1 (See below), together with a fifth, rare, cause, Bartter's syndrome. A sixth, metabolic cause, diabetes mellitus, is also presented in this table. In all forms of hyponatremia, the chloride ion concentration is also generally low since chloride is the chief counter-ion for sodium.

Interpreting and Correlating Abnormal Laboratory Values : Glucose Abnormalities

The major purpose of performing analyte determinations in the clinical laboratory is to aid in the diagnosis and management of patients with disease and individuals in health assessment. In this regard, the clinical pathologist/Clinical Biochemist/Clinical Microbiologist are often called upon as a consultant to explain abnormal laboratory values, especially those that do not seem to correlate with one another, and to recommend or even to order laboratory tests that may lead to the correct diagnosis in the work-up of patients for particular medical problems.

POCT : Point of Care testing - Introduction, Utility and Management

Point-of-care testing (POCT) is an emerging concept in laboratory medicine and has attracted considerable interest in the medical literature. Recent experience has revealed a variety of applications for these new technologies in