A Manual of Laboratory Diagnostic Tests [antikvár]

PREFACE This third edition of A Manual of Laboratory Diagnostic Tests is intended to be a comprehensive and up-to-date diagnostic reference manual for health-care practitioners and a teaching/learning tool for students in a variety of health-care areas: nursing, medicine, dentistry, medical assistants, medical technology, radiologic technology, physical therapy, and others. The preparation of this third edition is based on critical comments and suggestions from those who have read and used previous editions: practitioners, educators, and students, as well as on extensive library, laboratory, and hospital research. The decision to include new tests takes into consideration trends and issues in diagnostic health care and practice. For example, there is a definite tendency to substitute newer for older technologies. There has been a marked reduction over the past decade in the use of contrast radiology, with the exception of computed tomography (CT scan) and cardiac catheterizations. The number of cardiac catheterizations, especially for persons with myocardial infarction, has been on the rise, as has the use of Holter monitors. In what may be a possible substitution of one technology for another in regard to contrast x-ray filming, there is a significant growth rate in the use of diagnostic ultrasound. An important issue is the cost of health care. It is interesting to note that in studies done to determine whether or not changes in clinical practice had contributed to rising hospital costs, it was found that there was little change in total use of services from the 1970s to the 1980s. Findings showed that use of laboratory services remained the same and that, contrary to "conventional wisdom," laboratory tests did not contribute to rising costs. Moreover new imagery techniques were commonly substituted for older, more invasive procedures. This edition also reflects a definite trend to report laboratory test data in Systeme International (SI) units. This is a common practice in much of the world where such units are used on a daily basis in patient care and in research studies and publications. However, the underlying reason for advocating change to SI units is that biological components react on a molar basis in vivo. Normal values in this edition are reported in both conventional units and, whenever available, in units of the SI system. Alerts are given for panic (crisis or critical) laboratory values that have life and death significance to the patient and need to be reported to the attending physician immediately.