Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (2 page)

Jacques Wallach, pathologist, educator, and author of this book left us on August 10, 2010. He was 84. Forty years before that, he wrote the first edition, widely recognized as a necessary resource for both busy house staff and seasoned clinicians alike. It was the product of his vast experience as a clinical pathologist, his unquenchable thirst for medical knowledge, and his passion for teaching. He devoted tireless hours of research toward updating this book seven times since then. Several hundreds of thousands of copies have been distributed in numerous translations throughout the world.

As a resident in Internal Medicine in the mid-1980s, my first encounter with this book came in the early hours before our daily morning report, as my fellow house officers scurried to review the overnight admissions prior to presenting these cases to the Department Chief. The ensuing hour was usually punctuated by moments when one or more of us incurred the Chief’s wrath for failure to accurately appreciate the patient’s disorder or appropriately intervene. In an effort to avoid a similar fate, each of us would keep a copy of the book in an overfilled pocket of our lab coat to review quickly prior to this daily inquisition. Years later, I witnessed many students and house officers under my supervision do same, often secretly racing each other to the passage contained therein that would earn them the sought after recognition of their peers.

In the years that followed, I saw the third edition of the book become the fourth, fifth, and so on, never really appreciating the work that Jacques put into each update. Like many of us, however, I did appreciate the place that each update had among my collection of those clinical books, which were always kept within easy reach and never seemed to collect any dust in my personal medical library.

When I first met Jacques, I was impressed by his dedication and commitment to medical education. He taught pathology at Albert Einstein, Rutgers, and SUNY Downstate and consulted for Children’s Specialized Hospital in Mountainside, South Amboy Memorial Hospital, Kings County Hospital in Brooklyn, and for the Bronx Zoo. He also wrote
Rheumatic Heart Disease
(1962) and
Interpretation of Pediatric Tests
(1983) as well as over 40 articles for peer review medical journals. He was a Fellow of the American College of Physicians, the American Society of Clinical Pathologists, the College of American Pathologists, and the New York Academy of Medicine. From 1975 to 1985, he donated his time and expertise in pathology to laboratories around the world. His office was crammed with countless notes he made while researching, scrolled on small pieces of paper, and filed between the pages of dozens of medical books and journals, waiting their turn to adorn the pages of his next book. It was like he realized that clinicians and patients around the world depended on him to unlock the keys to their own medical mysteries, and he did not take that responsibility lightly. More recently, Jacques asked me to join his small list of distinguished contributors and lend some assistance in my own area of expertise. To contribute in some small way to his labor of love was truly an honor.

As the devoted teacher, nothing was more rewarding to Jacques than being able to impart the wisdom he had worked hard to accumulate to the pupil looking for guidance. This ninth edition and all subsequent editions, now entitled
Wallach’s Interpretation of Diagnostic Tests
, represent his legacy and his ongoing gift to physicians around the world who continue to use his guidance everyday to care for their patients. I have no doubt that nothing would have made him happier.

A
NTHONY
G. A
UTERI
, MD

Preface

In the 10th edition of Wallach’s, the authors continue to modify the content and organization based on feedback from readers as well as attempting to keep pace with a rapidly changing health care environment. Since the main focus of the textbook is to stress the most efficient use of clinical lab testing, we have changed the format so that the first section will now be devoted to disease states. Moreover, we have extended the presentation of the patient’s chief complaints and physical findings format to additional chapters such as pulmonary, cardiac, and neurologic disease states. We have added chapters on HLA, Transfusion Medicine, and OBGYN and updated the chapters on Molecular Diagnostics and Cardiology.

The second section will now list the individual lab tests in alphabetical order stressing the integration of the clinical laboratory results in the clinical decision-making process. When appropriate, tests will include the sensitivity, specificity, and positive and negative probability. Infectious disease assays as before are listed separately.

We have enhanced the index to make it easier for the reader to locate the subjects of interest. In addition, we have created a robust electronic version, which will include “hypertexting” of tests mentioned in the disease section referring back to the individual test section. This textbook does not include references to pathophysiology or therapy. However, common pitfalls and limitations of testing as well as identifying appropriate tests for specific clinical presentations are addressed.

As in previous editions, this textbook is geared to the primary care physician, subspecialists, physician’s assistant, nurse practitioner, as well as medical and nursing students. The 10th edition is not an exhaustive catalogue of disease states but a practical guide. We would appreciate continued feedback about changes we have instituted and further comments.

L. M
ICHAEL
S
NYDER
, MD

G
ARY
L
APIDAS

M
ARY
A. W
ILLIAMSON
, MT (ASCP), P
H
D

Preface to the First Edition

Results of laboratory tests may aid in

Discovering occult disease

Preventing irreparable damage (e.g., phenylketonuria)

Early diagnosis after onset of signs or symptoms

Differential diagnosis of various possible diseases

Determining the stage of the disease

Estimating the activity of the disease

Detecting the recurrence of disease

Monitoring the effect of therapy

Genetic counseling in familial conditions

Medicolegal problems, such as paternity suits

This book is written to help the physician achieve these purposes the least amount of

Duplication of texts

Waste of patient’s money

Overtaxing of laboratory facilities and personnel

Loss of physician’s time Confusion caused by the increasing number, variety, and complexity of tests currently available. Some of these tests may be unrequested but performed as part of routine surveys or hospital admission multitest screening.

In order to provide quick reference and maximum availability and usefulness, this handy-sized book features

Tabular and graphic style of concise presentation

Emphasis on serial time changes in laboratory findings in various stages of disease

Omission of rarely performed, irrelevant, esoteric, and outmoded laboratory tests

Exclusion of discussion of physiologic mechanisms, metabolic pathways, clinical features, and nonlaboratory aspects of disease

Discussion of only the more important diseases that the physician encounters and should be able to diagnose

This book is not

An encyclopedic compendium of clinical pathology

A technical manual

A substitute for good clinical judgment and basic knowledge of medicine

Deliberately omitted are

Technical procedures and directions

Photographs and illustrations of anatomic changes (e.g., blood cells, karyotypes, isotope scans)

Discussions of quality control

Selection of a referral laboratory

Performance of laboratory tests in the clinician’s own office

Bibliographic references, except for the most general reference texts in medicine, hematology, and clinical pathology and for some recent references to specific conditions

The usefulness and need for a book of this style, organization, and contents have been increased by such current trends as

The frequent lack of personal assistance, advice, and consultation in large commercial laboratories and hospital departments of clinical pathology, which are often specialized and fragmented as well as impersonal

Greater demand for the physician’s time

The development of many new tests

Faculty and administrators still assume that this essential area of medicine can be learned “intuitively” as it was 20 years ago and that it therefore requires little formal training. This attitude ignores changes in the number and variety of tests now available as well as their increased sophistication and basic value in establishing a diagnosis.

The contents of this book are organized to answer the questions most often posed by physicians when they require assistance from the pathologist. There is no other single adequate source of information presented in this fashion. It appears from numerous comments I have received that this book has succeeded in meeting the needs not only of practicing physicians and medical students but also of pathologists, technologists, and other medical personnel. It has been adopted by many schools of nursing and of medical technology, physician’s assistant training programs, and medical schools. Such widespread acceptance confirms my original premise in writing this book and is most gratifying.

A perusal of the table of contents and index will quickly show the general organization of the material by type of laboratory test or organ system or certain other categories. In order to maintain a concise format, separate chapters have not been organized for such categories as newborn, pediatric, and geriatric periods or for primary psychiatric or dermatologic diseases. A complete index provides maximum access to this information.

Obviously, these data are not original but have been adapted from many sources over the years. Only the selection, organization, manner of presentation, and emphasis are original. I have formulated this point of view during 40 years as a clinician and pathologist, viewing with pride the important and growing role of the laboratory but deeply regretting its inappropriate utilization.

This book was written to improve laboratory utilization by making it simpler for the physician to select and interpret the most useful laboratory tests for his clinical problems.

J.W.

Contents

Contributors

Tribute to Jacques Wallach

Preface

Preface to the First Edition

Introduction

CHAPTER
1    FALTs: Factors Affecting Laboratory Tests
Lokinendi V. Rao

SECTION 1    DISEASE STATES

CHAPTER
2    Autoimmune Diseases
M. Rabie Al-Turkmani

CHAPTER
3    Cardiovascular Disorders
Craig S. Smith

CHAPTER
4    Central Nervous System Disorders
Juliana G. Szakacs

CHAPTER
5    Digestive Diseases
L. Michael Snyder and Michael J. Mitchell

CHAPTER
6    Endocrine Diseases
Hongbo Yu

CHAPTER
7    Genitourinary System Disorders
Charles R. Kiefer

CHAPTER
8    Gynecologic and Obstetric Disorders
Juliana G. Szakacs

CHAPTER
9    Hematologic Disorders
Liberto Pechet

CHAPTER
10  Hereditary and Genetic Diseases
Marzena M. Galdzicka, Patricia Minehart Miron, and Edward I. Ginns

CHAPTER
11  Infectious Diseases
Michael J. Mitchell

CHAPTER
12  Renal Disorders
M. Rabie Al-Turkmani

CHAPTER
13  Respiratory, Metabolic, and Acid–Base Disorders
Lokinendi V. Rao and Michael J. Mitchell

CHAPTER
14  Toxicology and Therapeutic Drug Monitoring
Amanda J. Jenkins