Diagnosing Information and Courses from MediaLab, Inc.

Coagulation tests provide information that is used in diagnosing coagulation disorders, evaluating hemostatic function prior to surgery, and monitoring the effectiveness of anticoagulant therapy.

The diagnosis of hereditary hemochromatosis (HH) is made through a combination of laboratory tests and medical evaluation of a patient's signs and symptoms. Iron overload is identified by tests that evaluate iron metabolism, while molecular assays are needed to document mutations in the HFE gene or others such as hepcidin, hemojuvelin, or transferrin receptor. Individuals with documented iron overload who exhibit signs and symptoms consistent with HH and who possess HFE or other mutations are considered to have HH. Other causes of secondary iron overload may need to be ruled out.An example of a testing algorithm is shown.

The Westgard rules can be very helpful in determining errors, but can be confusing. Here are some hints and guidelines on using the Westgard rules: Run at least two controls, one normal and one abnormal. Each should be plotted on its own chart. The Westgard rules call for accepting a run if the control measurements are within 2 standard deviations. However, it is still possible for all measurements to be within this limit, and still violate rules 10x or 41S. You may want to check for violation of these two rules, even if the run passes rule 12S. The 12S rule is meant to simplify and speed up error-checking, and using it may result in fewer errors detected. Visit the www.westgard.com for more information. For the 22S, 41S, and 10x rules, make sure you review the normal controls, the abnormal controls and a combination of the two. For example, the 10x rule applies if the past 3 normal controls and the past 7 abnormal controls have all been above their respective means. For the rules that look back over several runs, it may be necessary to look at the control charts for previous months. The rule that is broken provides a clue as to whether the error was systematic or random. This can aid in diagnosing the problem with the procedure. If any rule is broken, do not report patient results until the problem, if any, has been resolved. Once the problem has been resolved, it may be necessary to redo patient samples from previous runs, especially if the error was systematic.

It is important to be able to recognize the presence of these changes and then identify them for several reasons:If the changes are pathological, their identification may aid the physician in diagnosing a specific condition.If the changes are not pathological, their identification alerts the physician to the fact that the changes are present, thus avoiding a possible misdiagnosis.If reactive, it indicates that although the cells are functioning normally, they are reacting to a stimulus. Indicating the presence of such cells may aid in determining the diagnosis or monitoring the course of disease once a diagnosis has been made.