Gathering Data Laboratory Tests/Diagnostic Procedures

Laboratory and other diagnostic studies are a part of the information-gathering stage providing supportive evidence. These studies aid in the management, maintenance, and restoration of health. In reviewing and interpreting laboratory tests, it is important to remember that the origin of the test material does not always correlate to an organ or body system (e.g., a urine test to detect the presence of bilirubin and urobilinogen could indicate liver disease, biliary obstruction, or hemolytic disease). In some cases, the results of a test are nonspecific, because they indicate only a disorder or abnormality and not the location of the cause of the problem (e.g., an elevated erythrocyte sedimentation rate suggests the presence but not the location of an inflammatory process).

In evaluating laboratory tests, it is advisable to consider which medications (e.g., heparin, promethazine) are being administered to the client, including over-the-counter and herbal supplements (e.g., vitamin E), because these have the potential to alter, blur, or falsify results, creating a misleading diagnostic picture.