CASTS—These urinary sediments are formed by coagulation of aluminous material in the kidney tubules. They are cylindrical and vary in diameter depending on the size of the renal tubule or duct of their origin. The sides are parallel, and the ends are usually rounded. Casts in the urine always indicate some form of kidney disorder and should always be reported. If casts are present in large numbers, the urine is almost sure to be positive for albumin. Casts containing organized structures are:
Types of casts:
CYLINDROIDS—Resemble hyaline casts but are more slender and have a slender tail that is often twisted or curled. They frequently are seen along with hyaline casts and have the same significance.
Other microscopic structures found in urine are:
These are not generally pathologic unless present in very large numbers. Certain types of crystals are pathologic; therefore, all crystals seen should be reported.
As mentioned in the beginning of this chapter, hospital corpsmen are required to have a basic knowledge of laboratory procedures. It is not expected that all hospital corpsmen be proficient in all phases of this field, but it is essential that they know how to perform the tests mentioned in this chapter, since they are eligible for duty independent of a medical officer.
The hospital corpsman is not expected to make diagnoses from test findings or to institute definitive treatment based upon them; however, with the availability of modern communications facilities, the results of these tests will greatly assist him or her in giving a clearer clinical picture to the supporting medical officer.
Needless to say, accuracy, neatness, and attention to detail are essential to obtain optimum test results. Remember also that these tests are only aids to diagnosis—many other clinical factors must be taken into consideration before treatment can be started.
The ability to perform clinical laboratory tests is a commendable attribute of the hospital corpsman. However, the entire effort can come to naught if proper recording and filing practices are ignored and the test results go astray.
Since the test results are a part of the patient’s clinical picture, their accuracy and veracity are vital. Since they have a bearing upon the immediate and future medical history, they are made part of the medical record. Erroneous and inaccurate laboratory results have been known to cause extensive embarrassment and medical complications.
As a hospital corpsman, it is your responsibility to assure effective administration of all laboratory reports in your department and to make sure that they are properly filed.
When accepting laboratory requests and specimens, make absolutely certain that the patient is adequately identified. Proper identification can prevent a great number of errors.