Urinalysis in Clinical Laboratory Practice

Helen M Free

• Publisher: CRC Press
• Year: 2018
• ISBN:
  9781351094368
• Edition: 1
• Topic: Medicina
• Subtopic: Bioquímica en medicina

This book discusses urinalysis in clinical laboratory practice, including a historical overview, methods, future endeavours.

Chapter 1

INTRODUCTION

Urine is a fluid which is continously formed in and excreted from the body. It provides important information with regard to many disorders and diseases. Accordingly, it is widely studied as an aid in diagnosing and monitoring the course of treatment of disease.¹ The information provided by urine in regard to health is somewhat more subtle and not so well-understood. It should be emphasized that urine information is of great importance in providing a profile of health, as well as of disease.

Urine has been referred to as a mirror which reflects activities within the body. It has also been identified as presenting a biopsy of the kidney. It is the principal route of waste removal of products of metabolism from the body. It is the human body’s chief pathway of response to provide some sort of regulation of the heterogeneous intake of foods and liquids.

Urine is an amazingly complex entity which has much information of a varied nature to contribute as a result of the measurement of many chemical and physical parameters. Table 1-1 emphasizes the fact that urine can provide information relative to many body systems and organs, and that its range of information extends much wider than just the kidney.

The analysis of urine can provide information about functions of the whole body as well as its many parts. Disorders of the kidney obviously modify the composition of the urine. But kidney disorders may also complicate many other body processes. Urine study may also reflect the situation when kidney function is normal, but other parts of the body are out of synchronization.

The magnitude of the attention which urine receives is attested to by a recent study² which dealt with only the low molecular weight constituents of human urine. This publication revealed that more than 1,000 technical and scientific papers related only to low molecular weight substances in urine appeared in the medical and scientific literature in 1 single year.

Free and Free³ have published an overview of urodynamics which includes various concepts on urine formation, composition, analysis, and study, along with specific facts related to the illustrated concepts.

TABLE 1-1

Information from Urine Study

Relates to:

Kidneys

Liver

Pancreas

Blood

Muscle

Electrolytes

Nutrition

Acid-Base equilibrium

Water balance

Carbohydrate, fat, and protein metabolism

Bone

Pregnancy

Inborn errors of metabolism

Drug abuse

Intoxications or poisoning

Urinary tract

Gastrointestinal tract

Hormones

Cardiovascular system

Infection

Respiratory system

Central nervous system

The present publication reviews information relating to the practical utility of urine study. It discusses a variety of methods for both the qualitative and quantitative analysis of urine. Some of the pitfalls are presented which can occur if both the urine specimen and its analysis are not treated with “tender loving care.” A brief glimpse of the history of urinalysis lends some perspective both to the present and to the subjective prediction which is made regarding the future of urinalysis.

REFERENCES

1.  Wilson, J. M. and Junger, G., Principles and Practice of Screening for Disease, Public Health Papers No. 34, World Health Organization, Geneva, 1968.

2.  Katz, S., Confer, A., Scott, C. D., Burtis, C. A., Jolley, R. L., Lee, N., McKee, S. A. Maryanoff, B. E., Pitt, W. W., and Warren, K. S., An Annotated Bibliography of Low-molecular-weight Constituents of Human Urine, Oak Ridge National Laboratory ORNL-TM, 1968, 2394.

3.  Free, A. H. and Free, H. M., Urodynamics, Concepts Relating to Urinalysis, Ames Company, Elkhart, Indiana, 1974.

Chapter 2

HISTORY

From earliest times, man has been curious about urine, and it has been suggested from quite crude ancient records that he recognized certain changes in urine which were associated with disease. Such changes were primarily those of color, consistency, and volume. The Babylonians and Sumerians studied the physical appearance of the urine and attempted to relate this to various forms of human ailments.¹ The early Hindu physicians also utilized urine as an aid to diagnosis. These doctors described “honey urine” as a urine which attracted ants, and pointed out that such urine was obtained from individuals having carbuncles. Primitive urinalysis in some instances included tasting the urine. Prior to the development of any written language for the recording and transmission of information, signs were used to denote certain important materials or substances. It is interesting to note that urine was one of the substances identified with a specific sign (Figure 2-1).²

As early as 400 B.C., Hippocrates made frequent reference in his writings to the importance of urine examinations in health and disease. He noted changes in urine during fevers in both children and adults, and mentioned differences in odor (probably due to ketonuria) and color (concentration?, blood?, bilirubin?, or porphyrin?). Approximately 500 years later, Galen (131–201 A.D.) again emphasized the importance of urine in the diagnosis and care of the patient. Moses Maimonides³ was an astute ancient physician who collected a series of aphorisms regarding the analysis of urine. It is of importance to appreciate that even in ancient times the urine was recognized as a fluid which could be utilized in the study of disease.

FIGURE 2-1. Ancient symbol for urine suggesting that it was one of the basic substances (elements) of nature.

Somewhat later, Theophilus Prostospatharius, a prominent medical diagnostician and captain of the guard of Emperor Heraclius, wrote a treatise on urine which was quoted for centuries. This document suggests that the examination of urine could be aided by applying heat to the specimen. He also proposed that the urine was derived from the blood.

Johannes Actuarius was the last of the Byzantine medical writers and died about 1283 A.D. He held the official position of uroscopist at the Byzantine court. Actuarius used a urine glass for observing the appearance and position of deposited sediment and suspended matter. A little later, in his treatise on diabetes, Avicenna mentioned the effect of food on the composition of the urine in this disease. Ismail of Jurjani, a prominent Persian physician of about 1000 A.D., described the practice of urine stu...