mosbys diagnostic and laboratory test reference 12th ed

The User’s Guide to Test Preparation and Procedures section outlines the responsi-bilities of health care providers to ensure that the tests are accu-rately and safely performed.. Use of

ROUTINE BLOOD TESTING

Many diagnostic and laboratory tests include the direction to perform routine blood testing and/or routine urine testing The protocol for those tests is presented here and will be cross-referenced within the many tests requiring them.

Before

Explain the procedure to the patient

Tell the patient if fasting is necessary (Fasting is most commonly required with glucose and lipid studies.)

If fasting is required, instruct the patient not to consume any food or fluids Only water is permitted Fasting requirements usually vary from 8 to 12 hours

Instruct the patient to continue taking medications unless told otherwise by the healthcare provider

During

• Collect the blood in a properly color-coded test tube (Table A, page xiv), which indicates the presence or absence of additives Tube stopper colors may vary with different manufacturers If uncertain, verify with the laboratory

ROUTINE URINE TESTING

Many diagnostic and laboratory tests include the direction to perform routine blood testing and/or routine urine testing The protocol for those tests is presented here and will be cross-referenced within the many tests requiring them.

Before

Explain the procedure to the patient

Inform the patient if food or fluid restrictions are needed

During

Random, fresh, or spot specimen:

• Instruct the patient to urinate into an appropriate sterile container

non-24-hour specimen:

1 Begin the 24-hour collection by discarding the first specimen

2 Collect all urine voided during the next 24 hours

3 Show the patient where to store the urine

4 Keep the urine on ice or refrigerated during the collection period Foley bags are kept in a basin of ice Some collec-tions require a preservative Check with the laboratory

5 Post the hours for the urine collection in a prominent place to prevent accidentally discarding a specimen

6 Instruct the patient to void before defecating so that urine

is not contaminated by stool

7 Remind the patient not to put toilet paper in the urine collection container

8 Collect the last specimen as close as possible to the end of the 24-hour period Add this urine to the collection

After

• Transport the specimen promptly to the laboratory

= Patient teaching

DIAGNOSTIC AND LABORATORY TEST

REFERENCE

Twelfth Edition

Kathleen Deska Pagana, PhD, RN

Professor Emeritus Department of Nursing

Lycoming College Williamsport, Pennsylvania

http://www.KathleenPagana.com

President, Pagana Keynotes & Presentations

Timothy J Pagana, MD, FACS

Medical Director The Kathryn Candor Lundy Breast Health Center

Susquehanna Health System

Williamsport, Pennsylvania

Theresa Noel Pagana, MD, FAAEM

Emergency Medicine Physician

Virtua Voorhees Hospital

Voorhees, New Jersey

All rights reserved No part of this publication may be reproduced or transmitted in any

form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

ISBN: 978-0-323-22576-2

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Notice

Knowledge and best practice in this field are constantly changing As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge

in evaluating and using any information, methods, compounds, or experiments described herein In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility With respect to any drug or pharmaceutical products identified, readers are advised

to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose

or formula, the method and duration of administration, and contraindications It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions.

To the fullest extent of the law, neither the Publisher nor the authors, contributors,

or editors assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

With love and adoration,

we dedicate this book to our grandchildren:

Ella Marie Gaul

Jocelyn Elizabeth Gaul

Timothy William Gaul

Justin Aquinas Gaul

Juliana Kathleen Pericci

Luke Michael Pericci

John Henry Bullen, V

reviewers

Crystal Botkin, MPH, CNMT, PET

Assistant Professor and Clinical Coordinator

Nuclear Medicine Technology Program

Doisy College of Health Sciences

Saint Louis University

St Louis, Missouri

Noelle C Bowdler, MD

Clinical Professor of Obstetrics and Gynecology

University of Iowa Hospitals and Clinics

Iowa City, Iowa

Eileen M Burd, PhD, D(ABMM)

Director, Clinical Microbiology

Laurence M Demers, PhD, DSc, DABCC, FACB

Distinguished Professor Emeritus, Pathology and Medicine M.S Hershey Medical Center

Pennsylvania State University

Medical Director, Clinical Pathology

Pathology Consultants of South Broward

Memorial Healthcare System

Hollywood, Florida

reviewers v Chuany Mark Lu, MD, PhD

Professor of Laboratory Medicine

University of California

Chief, Hematology and Hematopathology/Laboratory Medicine Service

Veterans Affairs Medical Center

San Francisco, California

Alexander J McAdam, MD, PhD

Associate Professor of Pathology

Harvard Medical School

Boston, Massachusetts

Ravinder Jit Singh, PhD

Director of Endocrine Laboratory

Mayo Clinic

Rochester, Minnesota

vi

preface

The 12th edition of Mosby’s Diagnostic and Laboratory Test

Reference provides the user with an up-to-date, essential

refer-ence that allows easy access to clinically relevant laboratory and diagnostic tests A unique feature of this handbook is its consis-tent format, which allows for quick reference without sacrificing the depth of detail necessary for a thorough understanding of diagnostic and laboratory testing All tests begin on a new page and are listed in alphabetical order by their complete names The alphabetical format is a strong feature of the book; it allows the user to locate tests quickly without first having to place them in

an appropriate category or body system The User’s Guide to Test Preparation and Procedures section outlines the responsi-bilities of health care providers to ensure that the tests are accu-rately and safely performed Use of this guide should eliminate the need for test repetition resulting from problems with patient preparation, test procedures, or collection techniques Every fea-ture of this book is designed to provide pertinent information

in a sequence that best simulates priorities in the clinical setting.The following information is provided, wherever applicable, for effective diagnostic and laboratory testing:

Name of test Tests are listed by their complete names A

complete list of abbreviations and alternate test names follows each main entry

Type of test This section identifies whether the test is, for

example, an x-ray procedure, ultrasound, nuclear scan, blood test, urine test, sputum test, or microscopic examination of tis-sue This section helps the reader identify the source of the labo-ratory specimen or location of the diagnostic procedure

Normal findings Where applicable, normal values are listed

for the infant, child, adult, and elderly person Also, where priate, values are separated into male and female It is important

appro-to realize that normal ranges of laboraappro-tory tests vary from tion to institution This variability is even more obvious among the various laboratory textbooks For this reason, we have delib-erately chosen not to add a table of normal values as an appendix, and we encourage the user to check the normal values at the institution where the test is performed This should be relatively easy because laboratory reports include normal values Results are given in both conventional units and the International System

institu-of Units (SI units) where possible

PB preface preface vii

Possible critical values These values give an indication of

results that are well outside the normal range These results require health care provider notification and usually result in some type of intervention The Joint Commission is looking at the timely and reliable communication of critical laboratory val-ues as one of its patient safety goals

Test explanation and related physiology This section

pro-vides a concise yet comprehensive description of each test It includes fundamental information about the test itself, specific indications for the test, how the test is performed, what disease

or disorder the various results may show, how it will affect the patient or client, and relevant pathophysiology that will enhance understanding of the test

Contraindications These data are crucial because they alert

health care providers to patients to whom the test should not

be administered Patients highlighted in this section frequently include those who are pregnant, are allergic to iodinated or con-trast dyes, or have bleeding disorders

Potential complications This section alerts the user to

potential problems that necessitate astute assessments and interventions For example, if a potential complication is renal failure, the implication may be to hydrate the patient before the test and force fluids after the test A typical potential com-plication for many x-ray procedures is allergy to iodinated dye Patient symptoms and appropriate interventions are described

in detail

Interfering factors This section contains pertinent

informa-tion because many factors can invalidate the test or make the test results unreliable An important feature is the inclusion of drugs that can interfere with test results Drugs that increase or decrease test values are always listed at the end of this section for consistency and quick access A drug symbol ( ) is used to emphasize these drug interferences

Procedure and patient care This section emphasizes the

role of nurses and other health care providers in diagnostic and laboratory testing by addressing psychosocial and physiologic interventions Patient teaching priorities are noted with a spe-cial icon ( ) to highlight information to be communicated to patients For quick access to essential information, this section is divided into before, during, and after time sequences

Before This section addresses the need to explain the

pro-cedure and to allay patient concerns or anxieties If patient consent is usually required, this is listed as a bulleted item

viii preface preface ix

Other important features include requirements such as fasting,

obtaining baseline values, and performing bowel preparations

During This section gives specific directions for clinical

specimen studies (e.g., urine and blood studies) Diagnostic

procedures and their variations are described in a numbered,

usually step-by-step format Important information, such as

who performs the test, where the study is performed, patient

sensation, and duration of the procedure, is bulleted for

emphasis The duration of the procedure is very helpful for

patient teaching because it indicates the time generally

allot-ted for each study

After This section includes vital information that the

nurse or other health care provider should heed or convey

after the test Examples include such factors as maintaining

bed rest, comparing pulses with baseline values, encouraging

fluid intake, and observing the patient for signs and symptoms

of sepsis

Abnormal findings As the name implies, this section lists

the abnormal findings for each study Diseases or conditions that

may be indicated by increased ( ) or decreased ( ) values are

listed where appropriate

Notes This blank space at the end of the tests facilitates

indi-vidualizing the studies according to the institution at which the

test is performed Variations in any area of the test (e.g., patient

preparation, test procedure, normal values, postprocedural care)

can be noted here

This logical format emphasizes clinically relevant information

The clarity of this format allows for quick understanding of

con-tent essential to both students and health care providers Color

has been used to help locate tests and to highlight critical

infor-mation (e.g., possible critical values) Color is also used in the

illustrations to enhance the reader’s understanding of many

diag-nostic procedures (e.g., bronchoscopy, fetoscopy, ERCP,

peri-cardiocentesis, TEE) Many tables are used to simplify complex

material on such topics as bioterrorism infectious agents, blood

collection tubes, hepatitis testing, and protein electrophoresis

Extensive cross-referencing exists throughout the book, which

facilitates understanding and helps the user tie together or locate

related studies, such as hemoglobin and hematocrit

New to this edition are standard guidelines for routine blood

and urine testing located on the inside front cover for easy access

A list of abbreviations for test names is included on the book’s

endpapers Appendix A includes a list of studies according to body

viii preface preface ix

system This list may familiarize the user with other related studies

the patient or client may need or the user may want to review This should be especially useful for students and health care pro-viders working in specialized areas Appendix B provides a list

of studies according to test type This list may help the user read

and learn about similarly performed tests and procedures (e.g., barium enema and barium swallow) Appendix C provides a list

of blood tests used for disease and organ panels Appendix D vides a list of symbols and units of measurement Finally, a compre-

pro-hensive index includes the names of all tests, their synonyms and abbreviations, and any other relevant terms found in the tests.Many new studies, such as galectin-3, nicotine and metabo-lites, pepsinogen, and thromboelastography, have been added All other studies have been revised and updated Outdated stud-ies have been eliminated

We sincerely thank our editors for their enthusiasm and tinued support We are most grateful to the many nurses and other health care providers who made the first eleven editions of this book so successful Thank you so much This success vali-dated the need for a user-friendly and quick-reference approach

con-to laboracon-tory and diagnostic testing

We invite additional comments from current users of this book so that we may continue to provide useful, relevant diag-nostic and laboratory test information to users of future editions

Kathleen D Pagana Timothy J Pagana Theresa N Pagana

Appendix C: Disease and organ panels, 1026

Appendix D: Symbols and units of measurement, 1030

Bibliography, 1032

Index, 1036

Figure 5 Bilirubin metabolism and excretion, 143

Figure 6 Bone marrow aspiration, 169

Figure 7 Bronchoscopy, 194

Figure 8 Cardiac catheterization, 216

Figure 9 Chorionic villus sampling, 255

Figure 10 Hemostasis and fibrinolysis, 264

Figure 11 Colposcopy, 274

Figure 12 Cardiac enzymes after myocardial infarction, 309

Figure 13 Cystoscopic examination of the male bladder, 326

Figure 14 Ureteral catheterization through the cystoscope, 327

Figure 15 Disseminated intravascular coagulation, 346

Figure 16 Ductoscopy, 354

Figure 17 ECG planes of reference, 360

Figure 18 Electrocardiography, 361

Figure 19 Endoscopic retrograde cholangiopancreatography, 386

Figure 20 Esophageal function studies, 400

Figure 27 Liver biopsy, 591

Figure 28 Lumbar puncture, 602

Figure 29 Transbronchial needle biopsy, 605

Figure 30 Stereotactic breast biopsy, 625

Figure 31 Oximetry, 674

Figure 32 Papanicolaou (Pap) smear, 683

Figure 33 Paracentesis, 685

Figure 34 Pericardiocentesis, 702

Figure 35 Rectal ultrasonography, 754

Figure 36 Lung volumes and capacities, 774

Figure 37 Renal biopsy, 793

Figure 38 Renovascular hypertension, 801

Figure 39 Rectal culture of the female, 831

Figure 40 Urethral culture of the male, 832

Figure 41 Thoracentesis, 884

Figure 42 Fibrin clot formation, 894

Figure 43 Transesophageal echocardiography, 922

xi

user’s guide to test preparation and procedures

Health care economics demands that laboratory and tic testing be performed accurately and in the least amount of time possible Tests should not have to be repeated because of improper patient preparation, test procedure, or specimen collec-tion technique The following guidelines delineate the responsi-bilities of health care providers to ensure safety of test procedures and accuracy of test results Guidelines are described for the fol-lowing major types of tests: blood, urine, stool, x-ray, nuclear scanning, ultrasound, and endoscopy

diagnos-Blood tests

Overview

Blood studies are used to assess a multitude of body processes and disorders Common studies include enzymes, serum lipids, electrolyte levels, red and white blood cell counts, clotting factors, hormone levels, and levels of breakdown products (e.g., blood urea nitrogen)

Multiphasic screening machines can perform many blood tests

simultaneously using a very small blood sample The advantages of using these machines are that results are available quickly and the cost is lower when compared with individually performing each test.Appendix C provides a list of current disease and organ pan-els For example, the basic metabolic panel and the comprehen-sive metabolic panel have replaced the Chem-7 and Chem-12 panels These changes are the result of federal guidelines that have standardized the nomenclature for chemistry panels

• If ordered, withhold medications until the blood is drawn

• Record the time of day when the blood test is drawn Some blood test results (e.g., those for cortisol) vary according

to a diurnal pattern, and this must be considered when blood levels are interpreted

• In general, two or three blood tests can be done per tube

of blood collected (e.g., two or three chemistry tests from one red-top tube of blood)

user’s guide to test preparation and procedures xiii u

• Note the patient’s position for certain tests (e.g., renin, because levels are affected by body position)

• Collect the blood in a properly color-coded test tube Blood collection tubes have color-coded stoppers to indi-cate the presence or absence of different types of additives (preservatives and anticoagulants) A preservative prevents change in the specimen, and an anticoagulant inhibits clot formation or coagulation Charts are available from the lab-oratory indicating the type of tube needed for each partic-ular blood test A representative chart is shown in Table A,

p xiv

• Follow the recommended order of draw when collecting

blood in tubes Draw specimens into nonadditive (e.g., red-top) tubes before drawing them into tubes with addi-tives This prevents contamination of the blood specimen with additives that may cause incorrect test results Fill the tubes in the following order:

1 Blood culture tubes (to maintain sterility)

2 Nonadditive tubes (e.g., red-top)

3 Coagulation tubes (e.g., blue-top)

4 Heparin tubes (e.g., green-top)

5 Ethylenediaminetetraacetic acid (EDTA) tubes (e.g., lavender-top)

6 Oxalate/fluoride tubes (e.g., gray-top)

• To obtain valid results, do not fasten the tourniquet for longer than 1 minute Prolonged tourniquet application can cause stasis and hemoconcentration

• Collect the blood specimen from the arm without an venous (IV) device, if possible IV infusion can influence test results

intra-• Do not use the arm bearing a dialysis arteriovenous fistula for venipuncture unless the physician specifically autho-rizes it

• Because of the risk of cellulitis, do not take specimens from the side on which a mastectomy or axillary lymph node dissection was performed

• Follow the unit guidelines for drawing blood from an indwelling venous catheter (e.g., a triple-lumen catheter) Guidelines will specify the amount of blood to be drawn from the catheter and discarded before blood is collected for laboratory studies The guidelines will also indicate the amount and type of solution needed to flush the catheter after drawing the blood to prevent clotting

TABLE A Common blood collection tubes

Blood urea nitrogen

gel for serum separator

Serum separator tube for serum determinatives in chemistry and serology

Chemistry, serology

Heparin/ethylene-diaminetetraacetic acid (EDTA)

Purple or

Glucose

user’s guide to test preparation and procedures xv u

• Do not shake the blood specimen Hemolysis may result from vigorous shaking and can invalidate test results Use gentle inversions

• Collect blood cultures before the initiation of antibiotic

therapy Blood cultures are often drawn when the patient manifests a fever Often two or three cultures are taken at 30-minute intervals from different venipuncture sites

• Skin punctures can be used for blood tests on capillary blood

Common puncture sites include the fingertips, earlobes, and heel surfaces Fingertips are often used for small children, and the heel is the most commonly used site for infants

• Ensure that the blood tubes are correctly labeled and delivered to the laboratory

• After the specimen is drawn, apply pressure or a sure dressing to the venipuncture site Assess the site for bleeding

pres-• If the patient fasted before the blood test, reinstitute the appropriate diet

Urine tests

Overview

Urine tests are easy to obtain and provide valuable information about many body system functions (e.g., kidney function, glu-cose metabolism, and various hormone levels) The ability of the patient to collect specimens appropriately should be assessed to determine the need for assistance

Guidelines

• Observe universal precautions in collecting a urine specimen

• Use the first morning specimen for routine urinalysis because it is more concentrated To collect a first morn-ing specimen, have the patient void before going to bed and collect the first urine specimen immediately upon rising

• Random urine specimens can be collected at any time

They are usually obtained during daytime hours and out any prior patient preparation

with-• If a culture and sensitivity (C&S) study is required or if the

specimen is likely to be contaminated by vaginal discharge or

bleeding, collect a clean-catch or midstream specimen This

requires meticulous cleansing of the urinary meatus with

an antiseptic preparation to reduce contamination of the specimen by external organisms Then the cleansing agent must be completely removed because it may contaminate

xvi user’s guide to test preparation and procedures

the specimen Obtain the midstream collection by doing the

following:

1 Have the patient begin to urinate in a bedpan, urinal,

or toilet and then stop urinating (This washes the urine out of the distal urethra.)

2 Correctly position a sterile urine container, and have the patient void 3 to 4 ounces of urine into it

3 Cap the container

4 Allow the patient to finish voiding

• One-time composite urine specimens are collected over a

period that may range anywhere from 2 to 24 hours To collect a timed specimen, instruct the patient to void and

discard the first specimen This is noted as the start time of

the test Instruct the patient to save all subsequent urine

in a special container for the designated period Remind the patient to void before defecating so that urine is not contaminated by feces Also, instruct the patient not to put toilet paper in the collection container A preservative is usually used in the collection container At the end of the specified time period, have the patient void and then add this urine to the specimen container, thus completing the collection process

• Collection containers for 24-hour urine specimens should

hold 3 to 4 L of urine and have tight-fitting lids They should be labeled with the patient’s name, the starting col-lection date and time, the ending collection date and time, the name of the test, the preservative, and storage require-ments during collection

• Many urine collections require preservatives to maintain their stability during the collection period Some specimens are best preserved by being kept on ice or refrigerated

• Urinary catheterization may be needed for patients who

are unable to void This procedure is not preferred because

of patient discomfort and the risk of patient infection

• For patients with an indwelling urinary catheter, obtain a

specimen by aseptically inserting a needleless syringe into the catheter at a drainage port distal to the sleeve leading

to the balloon Aspirate urine and then place it in a sterile urine container The urine that accumulates in the plastic reservoir bag should never be used for a urine test

• Urine specimens from infants and young children are

usu-ally collected in a disposable pouch called a U bag This

bag has an adhesive backing around the opening to attach

to the child’s perineum After the bag is in place, check the

user’s guide to test preparation and procedures xvii u

child every 15 minutes to see if an adequate specimen has been collected Remove the specimen as soon as possible after the collection, and then label it and transport it to the laboratory

Stool tests

Overview

The examination of feces provides important information that aids in the differential diagnosis of various gastrointestinal dis-orders Fecal studies may also be used for microbiologic studies, chemical determinations, and parasitic examinations

Guidelines

• Observe universal precautions in collecting a stool specimen

• Collect stool specimens in a clean container with a fitted lid

• Do not mix urine and toilet paper with the stool specimen Both can contaminate the specimen and alter the results

• Fecal analysis for occult blood, white blood cells, or tative fecal fat requires only a small amount of a randomly collected specimen

quali-• Quantitative tests for daily fecal excretion of a particular substance require a minimum of a 3-day fecal collection This collection is necessary because the daily excre-tion of feces does not correlate well with the amount of food ingested by the patient in the same 24-hour period Refrigerate specimens or keep them on ice during the col-lection period Collect stool in a 1-gallon container

• A small amount of fecal blood that is not visually apparent

is termed occult blood Chemical tests using commercially

prepared slides are routinely used to detect fecal blood Numerous commercial slide tests use guaiac as the indica-tor These guaiac tests are routinely done on nursing units and in medical offices

• Consider various factors (e.g., other diagnostic tests and medications) in planning the stool collection For exam-ple, if the patient is scheduled for x-ray studies with barium sulfate, collect the stool specimen first Various medica-tions (e.g., tetracyclines and antidiarrheal preparations) affect the detection of intestinal parasites

• Some fecal collections require dietary restrictions before the collection (e.g., tests for occult blood)

• Correctly label and deliver stool specimens to the tory within 30 minutes after collection If you are unable

labora-to deliver the specimen within 30 minutes, it may be refrigerated for up to 2 hours

xviii user’s guide to test preparation and procedures

X-ray studies

Overview

Because of the ability of x-rays to penetrate tissues, x-ray ies provide a valuable picture of body structures X-ray studies can be as simple as a routine chest x-ray image or as complex as dye-enhanced cardiac catheterization With the concern about radiation exposure, it is important to realize that the patient may question if the proposed benefits outweigh the risks involved

stud-Guidelines

• Assess the patient for any similar or recent x-ray procedures

• Evaluate the patient for allergies to iodine dye Carefully

consider the following points:

◦ Many types of contrast media are used in radiographic studies For example, organic iodides and iodized oils are frequently used

◦ Allergic reactions to iodinated dye may vary from mild flushing, itching, and urticaria to severe, life-threatening anaphylaxis (evidenced by respiratory distress, drop

in blood pressure, or shock) In the unusual event of anaphylaxis, the patient is treated with diphenhydramine (Benadryl), steroids, and epinephrine Oxygen and endotracheal equipment should be on hand for immediate use

◦ The patient should always be assessed for allergies

to iodine dye before it is administered Inform the radiologist if an allergy to iodinated contrast is suspected The radiologist may prescribe Benadryl and steroid preparation to be administered before testing Usually, hypoallergenic nonionic contrast will be administered to allergic patients during the test

◦ After the x-ray procedure, evaluate the patient for a delayed reaction to dye (e.g., dyspnea, rashes, tachycardia, hives) This usually occurs within 2 to 6 hours after the test Treat with antihistamines or steroids

• Assess the patient for any evidence of dehydration or renal disease Usually blood urea nitrogen (BUN) and creati-nine tests are obtained prior to administration of iodine- containing intravenous contrast Hydration may be required prior to the administration of iodine

• Assess the patient for diabetes Diabetics are particularly susceptible to renal disease caused by the administra-tion of iodine-containing intravenous contrast Diabetic patients who take metformin (Glucophage) or glyburide

user’s guide to test preparation and procedures xix u

(Micronase) are particularly susceptible to lactic acidosis and hypoglycemia These medications may be discontin-ued for 1 to 4 days prior to and 1 to 2 days after the admin-istration of iodine Check with the x-ray department

• Women in their childbearing years should have x-ray examinations during menses or within 10 to 14 days after the onset of menses to avoid possible exposure to a fetus

• Pregnant women should not have x-ray procedures unless the benefits outweigh the risk of damage to the fetus

• Note whether other x-ray studies are being planned; ule them in the appropriate sequence For example, x-ray examinations that do not require contrast should precede examinations that do require contrast X-ray studies with barium should be scheduled after ultrasonography

sched-• Note the necessary dietary restrictions Such studies as barium enema and intravenous pyelogram (IVP) are more accurate if the patient is kept NPO (fasting from food and liquids) for several hours before the test

• Determine whether bowel preparations are necessary For example, barium enemas and IVPs require bowel-cleansing regimens

• Determine whether signed consent forms are required These are necessary for most invasive x-ray procedures

• Remove metal objects (e.g., necklaces, watches) because they can hinder visualization of the x-ray field

• Patient aftercare is determined by the type of x-ray dure For example, a patient having a simple chest x-ray study will not require postprocedure care However, inva-sive x-ray procedures involving contrast dyes (e.g., cardiac catheterization) require extensive nursing measures to detect potential complications

proce-Nuclear scanning

Overview

With the administration of a radionuclide and subsequent surement of the radiation of a particular organ, functional abnor-malities of various body areas (e.g., brain, heart, lung, bones) can

mea-be detected Because the half-lives of the radioisotopes are short, only minimal radiation exposure occurs

Guidelines

• Radiopharmaceuticals concentrate in target organs by ous mechanisms For example, some labeled compounds (e.g., hippuran) are cleared from the blood and excreted

vari-xx user’s guide to test preparation and procedures

by the kidneys Some phosphate compounds concentrate

in the bone and infarcted tissue Lung function can be studied by imaging the distribution of inhaled gases or aerosols

• Note whether the patient has had any recent exposure to radionuclides The previous study could interfere with the interpretation of the current study

• Note the patient’s age and current weight This tion is used to calculate the dose of radioactive substances

informa-• Nuclear scans are contraindicated in pregnant women and nursing mothers

• Many scanning procedures do not require special tion However, a few have special requirements For exam-ple, for bone scanning, the patient is encouraged to drink several glasses of water between the time of the injection

prepara-of the isotope and the actual scanning For some studies, blocking agents may need to be given to prevent other organs from taking up the isotope

• For most nuclear scans, a small amount of an specific radionuclide is given orally or injected intravenously After the radioisotope concentrates in the desired area, the area is scanned The scanning procedure usually takes place

organ-in the nuclear medicorgan-ine department

• Instruct the patient to lie still during the scanning

• Usually encourage the patient to drink extra fluids to enhance excretion of the radionuclide after the test is finished

• Although the amount of radionuclide excreted in the urine

is very low, rubber gloves are sometimes recommended if the urine must be handled Some hospitals may advise the patient to flush the toilet several times after voiding

Ultrasound studies

Overview

In diagnostic ultrasonography, harmless high-frequency sound waves are emitted and penetrate the organ being studied The sound waves bounce back to the sensor and are electronically converted into a picture of the organ Ultrasonography is used

to assess a variety of body areas, including the pelvis, abdomen, breast, heart, and pregnant uterus

Guidelines

• Most ultrasound procedures require little or no preparation However, the patient having a pelvic sonogram needs a full bladder, and the patient having an ultrasound examination

of the gallbladder must be kept NPO before the procedure

user’s guide to test preparation and procedures xxi u

• Ultrasound examinations are usually performed in an ultrasound room; however, they can be performed in the patient unit

• For ultrasound, a greasy paste is applied to the skin ing the desired organ This paste is used to enhance sound transmission and reception because air impedes transmis-sion of sound waves to the body

overly-• Because of the noninvasive nature of ultrasonography, no special measures are needed after the study except for help-ing the patient remove the ultrasound paste

• Ultrasound examinations have no radiation risk

• Ultrasound examinations can be repeated as many times as necessary without being harmful to the patient No cumu-lative effect has been seen

• Barium has an adverse effect on the quality of abdominal studies For this reason, schedule ultrasound of the abdo-men before barium studies

• Large amounts of gas in the bowel obstruct visualization

of the bowel This is because bowel gas is a reflector of sound

Endoscopy procedures

Overview

With the help of a lighted, flexible instrument, internal structures

of many areas of the body (e.g., stomach, colon, joints, bronchi, urinary system, and biliary tree) can be directly viewed The spe-cific purpose and procedure should be reviewed with the patient

Guidelines

• Preparation for an endoscopic procedure varies according

to the internal structure being examined For example, examination of the stomach (gastroscopy) will require the passage of an instrument through the esophagus and into the stomach The patient is kept NPO for 8 to 12 hours before the test to prevent gagging, vomiting, and aspira-tion For colonoscopy, an instrument is passed through the rectum and into the colon Therefore, the bowel must be cleansed and free of fecal material to afford proper visual-ization Arthroscopic examination of the knee joint is usu-ally done with the patient under general anesthesia, which necessitates routine preoperative care

• Schedule endoscopic examinations before barium studies

• Obtain a signed consent for endoscopic procedures

xxii user’s guide to test preparation and procedures

• Endoscopic procedures are preferably performed by a physician in a specially equipped endoscopy room or in an operating room However, some kinds can safely be per-formed at the bedside

• Air is instilled into the bowel during colon examinations to maintain patency of the bowel lumen and to afford better visualization This sometimes causes gas pains

• In addition to visualization of the desired area, special cedures can be performed Biopsies can be obtained, and bleeding ulcers can be cauterized Also, knee surgery can

pro-be performed during arthroscopy

• Specific postprocedure interventions are determined by the type of endoscopic examination performed All pro-cedures have the potential complication of perforation and bleeding Most procedures use some type of sedation; safety precautions should be observed until the effects of the sedatives have worn off

• After colonoscopy and similar studies, the patient may complain of rectal discomfort A warm tub bath may be soothing

• Usually keep the patient NPO for 2 hours after endoscopic procedures of the upper gastrointestinal system Be certain that swallow, gag, and cough reflexes are present before permitting fluids or liquids to be ingested orally

abdominal ultrasound 1

A

abdominal ultrasound (Abdominal sonogram)

Type of test Ultrasound

Normal findings Normal abdominal aorta, liver, gallbladder,

bile ducts, pancreas, kidneys, ureters, and bladder

Test explanation and related physiology

Through the use of reflected sound waves, ultrasonography provides accurate visualization of the abdominal aorta, liver, gallbladder, pancreas, bile ducts, kidneys, ureters, and bladder The technique of ultrasonography requires the emission of high- frequency sound waves from a transducer to penetrate the partic-ular organ being studied The sound waves are bounced back to the transducer and are then electronically converted into a picto-rial image (Figure 1) Real-time ultrasound provides an accurate picture of the organ being studied Doppler ultrasound provides information concerning blood flow to those organs

The kidney is ultrasonographically evaluated to diagnose and locate renal cysts, to differentiate renal cysts from solid renal tumors, to demonstrate renal and pelvic calculi, to docu-ment hydronephrosis, to guide a percutaneously inserted needle for cyst aspiration or biopsy, and to place a nephrostomy tube Ultrasound of the urologic tract is also used to detect malformed

or ectopic kidneys and perinephric abscesses Renal tion surveillance is possible with ultrasound One advantage of

transplanta-a kidney sonogrtransplanta-am over intrtransplanta-avenous pyelogrtransplanta-aphy (see p 778)

is that it can be performed on patients with impaired renal tion because no intravenous contrast is required

func-Endourethral urologic ultrasound can also be performed

through a stent that has a transducer at its end The stent probe

is placed into the urethra to examine that segment for diverticula The stent probe can then be advanced into the bladder where the depth of a tumor into the bladder wall can be measured With the use of wire lead guidance, the stent probe can be passed into the ureter where stones (especially those embedded into the sub-mucosa), tumors, or extraurethral compression can be identified and localized Finally, as the probe is advanced in the proximal ureter, renal tumors or cysts can be better delineated

The prostate and the testes are discussed on pp 754 and 816.Another use of sonography is in the assessment of the abdominal aorta for aneurysmal dilation Sonographic evi-dence of an aortic aneurysm greater than 5 cm or any size aneurysm that is documented to be significantly enlarging is an

2 abdominal ultrasound

indication for abdominal aorta aneurysm resection Ultrasound

is also an ideal way to evaluate aneurysm patients before and after surgery

Ultrasound is used to detect cystic structures of the liver

(e.g., benign cysts, hepatic abscesses, and dilated hepatic ducts) and solid intrahepatic tumors (primary and metastatic) Hepatic ultrasound also can be performed intraoperatively by using a ster-ile probe This technique allows for accurate location of small,

nonpalpable hepatic tumors or abscesses The gallbladder and

bile ducts can be visualized and examined for evidence of

gall-stones, polyps, or dilation secondary to obstructive strictures or

tumors The pancreas is examined for evidence of tumors,

pseu-docysts, acute inflammation, chronic inflammation, or pancreatic abscesses Ultrasound of the pancreas is frequently performed serially to document and demonstrate resolution of acute pan-creatic inflammatory processes

FIGURE 1 Ultrasound of the abdomen

abdominal ultrasound 3

A

Because this study requires no contrast material and has no associated radiation, it is especially useful in patients who are allergic to contrast and in those who are pregnant Fasting may

be preferred, but it is not mandatory (See discussion of pelvic ultrasonography [p 697] for sonographic evaluation of pelvic organs.)

Interfering factors

• Air impedes transmission of ultrasonic waves into the body The use of a lubricant is essential to ensure good transmission

of sound waves to and from the body

• Barium blocks transmission of ultrasonic waves For this son, ultrasonography of the abdomen should be performed before any barium contrast studies

rea-• Large amounts of gas in the bowel distort visualization of abdominal organs because bowel gas reflects sound Likewise, ultrasonic evaluation of the lungs yields poor results

• Obesity may affect the results of the study because sound waves are altered by fatty tissue

• Movement causes artifacts Some patients may need to be sedated to remain still Uncooperative patients (especially children) may not be candidates for ultrasonography

• Because ultrasonography requires direct contact of the ducer and the skin, it may not be possible to perform this study in postoperative patients with dressings

trans-• The quality of the ultrasound image and the sufficiency of the study depend to a very large part on the abilities of the ultra-sound technologist performing the study

Procedure and patient care

Before

Explain the procedure to the patient

Tell the patient that fasting may or may not be required, depending on the organ to be examined No fasting is required for ultrasonography of the abdominal aorta, kidney, liver, spleen, or pancreas Fasting, however, is preferred for ultrasound of the gallbladder and bile ducts

During

• Note the following procedural steps:

1 The patient is placed on the ultrasonography table in the prone or supine position, depending on the organ to be studied

4 abdominal ultrasound

2 A greasy conductive paste (coupling agent) is applied to the patient’s skin This paste is used to enhance sound wave transmission and reception

3 A transducer is placed over the skin

4 Pictures are taken of the reflections from the organs

• The test is completed in approximately 20 minutes, usually by

an ultrasound technologist, and is interpreted by a radiologist Tell the patient that this procedure causes no discomfort

After

• Remove the coupling agent from the patient’s skin

• Note that if a biopsy is done, refer to biopsy of the specific organ (e.g., liver or kidney biopsy)

Abdominal aorta

Aneurysm

Abdominal cavity

AscitesAbscess

notes

acetylcholine receptor antibody panel 5

ACh receptor (muscle) binding antibodies: ≤0.02 nmol/L

ACh receptor (muscle) modulating antibodies: 0 to 20% (reported

as % loss of AChR)

Striational (striated muscle) antibodies: <1:60

Test explanation and related physiology

These antibodies may cause blocks in neuromuscular

trans-mission by interfering with the binding of acetylcholine (ACh)

to ACh receptor (AChR) sites on the muscle membrane, thereby

preventing muscle contraction It is this phenomenon that acterizes myasthenia gravis (MG) Antibodies to AChR occur

char-in more than 85% of patients with acquired MG Lower levels are seen in patients with ocular MG only The presence of these antibodies is virtually diagnostic of MG, but a negative test does not exclude the disease The measured titers do not correspond well with the severity of MG in different patients In an indi-vidual patient, however, antibody levels are particularly useful in monitoring response to therapy As the patient improves, anti-body titers decrease In adults with MG, there is at least a 20% occurrence of thymoma or other neoplasm Neoplasms are an endogenous source of the antigens driving production of AChR autoantibodies

There are several AChR antibodies that can be associated with

MG The AChR-binding antibody can activate complement and lead to loss of AChR The AChR-modulating antibody causes

receptor endocytosis, resulting in loss of AChR expression, which correlates most closely with clinical severity of disease It is the most sensitive test A positive modulating antibody test may indicate subclinical MG, contraindicating the use of curare-like

drugs during surgery The AChR-blocking antibody may impair

binding of acetylcholine to the receptor, leading to poor muscle contraction It is the least sensitive test (positive in only 61% of patients with MG) Not all of the antibodies impair neuromuscu-lar transmission For example, striational antibodies are directed

at sarcomeric proteins that don’t impair neuromuscular function

Anti-striated muscle antibody (striated muscle antibody, IgG)

titers greater than or equal to 1:80 are suggestive of myasthenia This antibody is detectable in 30% to 40% of anti-AChR-negative

6 acetylcholine receptor antibody panel

patients (particularly those with bulbar symptoms only) However, striated muscle antibody can be found in rheumatic fever, myocar-dial infarction, and a variety of postcardiotomy states

Drugs that may cause increased levels include muscle paralytic

medicines (succinylcholine) and snake venom

Immunosuppressive drugs may suppress the formation

of these antibodies in patients with subclinical MG

Procedure and patient care

• See inside front cover for Routine Blood Testing

acid phosphatase 7

A

acid phosphatase (Prostatic acid phosphatase [PAP],

Tartrate-resistant acid phosphatase [TRAP])

Type of test Blood

Normal findings

Adult/elderly: 0.13-0.63 units/L (Roy, Brower, Hayden; 37 ° C)

or 2.2-10.5 units/L (SI units)

Child: 8.6-12.6 units/mL (30 ° C)

Newborn: 10.4-16.4 units/mL (30 ° C)

Test explanation and related physiology

Acid phosphatase is found in many tissues, including liver, red blood cells, bone marrow, and platelets The highest levels are found in the prostate gland—the PAP isoenzyme Usually (but not always) elevated levels are seen in patients with prostatic can-cer that has metastasized beyond the capsule to other parts of the body, especially bone The degree of elevation indicates the extent of disease

Because acid phosphatase is also found at high concentrations

in seminal fluid, this test can be performed on vaginal secretions

to investigate alleged rape This is now the primary use of PAP testing High levels of acid phosphatase also exist in white blood cells (mostly monocytes and lymphocytes) They are helpful in determining the clinical course of patients with lymphoprolif-erative diseases and hairy cell leukemia Acid phosphatase is a lysosomal enzyme Therefore, lysosomal storage diseases (e.g., Gaucher disease and Niemann-Pick disease) are associated with elevated levels

Interfering factors

• Alkaline and acid phosphatase are very similar enzymes that differ in the pH at which they are identified Any condition associated with very high levels of alkaline phosphatase may falsely indicate high acid phosphatase levels

• Falsely high levels of acid phosphatase may occur in males after a digital examination or after instrumentation of the prostate (e.g., cystoscopy) because of prostatic stimulation

Drugs that may cause increased levels of acid phosphatase

include alglucerase, androgens (in females), and clofibrate

Drugs that may cause decreased levels include alcohol,

fluo-rides, heparin, oxalates, and phosphates

8 acid phosphatase

Procedure and patient care

• See inside front cover for Routine Blood Testing

• Fasting: no

• Blood tube commonly used: red

• Avoid hemolysis Red blood cells contain acid phosphatase

• Note on the laboratory slip if the patient has had a prostatic examination or instrumentation of the prostate within the last

24 hours

• Do not leave the specimen at room temperature for 1 hour or

longer, because the enzyme is heat- and pH-sensitive and its activity will decrease

Metastasis to the bone

Sickle cell crisis

activated clotting time 9

A

activated clotting time (ACT, Activated coagulation time)

Type of test Blood

Normal findings 70-120 sec

Therapeutic range for anticoagulation: 150-600 sec

(Normal ranges and anticoagulation ranges vary according to type of laboratory procedure and particular therapy.)

Possible critical values Depends upon use for the test and clinical situation

Test explanation and related physiology

The ACT is primarily used to measure the anticoagulant effect

of heparin or other direct thrombin inhibitors during cardiac angioplasty, hemodialysis, and cardiopulmonary bypass (CPB) surgery This test measures the time for whole blood to clot after

the addition of particulate activators It is similar to the activated

partial thromboplastin time (APTT, p 693) in that it measures

the ability of the intrinsic pathway to begin clot formation by

activating factor XII (see Figure 10, p 264) By checking the blood clotting status with ACT, the response to unfractionated heparin therapy can be monitored

Both the APTT and the ACT can be used to monitor heparin therapy for patients during CPB However, the ACT has several advantages over the APTT First, the ACT is more accurate than the APTT when high doses of heparin are used for anticoagu-lation This makes it especially useful during clinical situations requiring high-dose heparin, such as during CPB, when high-dose anticoagulation is necessary at levels 10 times those used for venous thrombosis The APTT is not measurable at these high doses The accepted goal for the ACT is 400 to 480 seconds during CPB

Second, the ACT is both less expensive and more easily formed, even at the bedside This allows for immediate accessibil-ity and decreased turnaround time The capability to perform the ACT at the point of care makes the ACT particularly useful for patients requiring angioplasty, hemodialysis, and CPB

per-A nomogram is often used as a guide to reach the desired level

of anticoagulation This nomogram is used in determining the dose of protamine to neutralize the heparin upon completion of these procedures The ACT is used in determining when it is safe

to remove the vascular access upon completion of these

proce-dures The benefits of the modified ACT test are that it requires

a smaller-volume blood specimen; it can be automated; it can use

10 activated clotting time

standardized blood/reagent mixing; and it provides faster ting time results than the conventional ACT The modified ACT

clot-is now being used more frequently

kid-• A clotted specimen can increase ACT measurements

Procedure and patient care

• See inside front cover for Routine Blood Testing

• Fasting: no

• Blood tube commonly used: verify with lab

• Less than 1 mL of blood is collected and placed in a machine

at the bedside When a clot forms, the ACT value is displayed

• If the patient is receiving a continuous heparin drip, the blood sample is obtained from the arm without the intravenous catheter

• The bleeding time will be prolonged because of tion therapy

anticoagula-• Assess the patient to detect possible bleeding Check for blood

in the urine and all other excretions, and assess the patient for bruises, petechiae, and low back pain

Abnormal findings

Increased levels Decreased levels

Heparin administration Thrombosis

Clotting factor deficiencies

Cirrhosis of the liver

Lupus inhibitor

Warfarin administration

notes

adrenocorticotropic hormone 11

A

adrenocorticotropic hormone (ACTH, Corticotropin)

Type of test Blood

Normal findings

Adult/elderly:

Female: 19 years and older: 6-58 pg/mL

Male: 19 years and older: 7-69 pg/mL

Children:

Male and female: 10-18 years: 6-55 pg/mL

Male and female: 1 week-9 years: 5-46 pg/mL

Test explanation and related physiology

The ACTH tests the anterior pituitary gland function and provides the greatest insight into the causes of either Cushing syndrome (overproduction of cortisol) or Addison disease (underproduction of cortisol) An elaborate feedback mechanism for cortisol exists to coordinate the function of the hypothala-mus, pituitary gland, and adrenal glands ACTH is an impor-tant part of this mechanism Corticotropin-releasing hormone (CRH) is made in the hypothalamus This stimulates ACTH production in the anterior pituitary gland This, in turn, stimu-lates the adrenal cortex to produce cortisol The rising levels of cortisol act as negative feedback and curtail further production

of CRH and ACTH

In the patient with Cushing syndrome, an elevated ACTH level can be caused by a pituitary or a nonpituitary (ectopic) ACTH-producing tumor, usually in the lung, pancreas, thymus,

or ovary ACTH levels over 200 pg/mL usually indicate pic ACTH production If the ACTH level is below normal in a patient with Cushing syndrome, an adrenal adenoma or carci-noma is probably the cause of the hyperfunction

ecto-In patients with Addison disease, an elevated ACTH level indicates primary adrenal gland failure, as in adrenal gland destruction caused by infarction, hemorrhage, or autoimmunity; surgical removal of the adrenal gland; congenital enzyme defi-ciency; or adrenal suppression after prolonged ingestion of exog-enous steroids If the ACTH level is below normal in a patient with adrenal insufficiency, hypopituitarism is most probably the cause of the hypofunction

One must be aware that there is a diurnal variation of ACTH levels that corresponds to variation of cortisol levels Levels in evening (8 pm to 10 pm) samples are usually one half to two thirds those of morning (4 am to 8 am) specimens This diurnal variation

12 adrenocorticotropic hormone

is lost when disease (especially neoplasm) affects the pituitary or adrenal glands Likewise, stress can blunt or eliminate this nor-mal diurnal variation

Interfering factors

• Stress (trauma, pyrogens, or hypoglycemia) and pregnancy can increase levels

• Recently administered radioisotope scans can affect levels

Drugs that may cause increased ACTH levels include

amino-glutethimide, amphetamines, estrogens, ethanol, insulin, metyrapone, spironolactone, and vasopressin

Corticosteroids may decrease ACTH levels.

Procedure and patient care

• See inside front cover for Routine Blood Testing

• Fasting: yes

• Blood tube commonly used: green

• Evaluate the patient for stress factors that could invalidate the test results

• Evaluate the patient for sleep pattern abnormalities With a normal sleep pattern, the ACTH level is the highest between

4 am and 8 am and the lowest around 9 pm

• Chill the blood tube to prevent enzymatic degradation of ACTH

• Place the specimen in ice water and send it to the chemistry laboratory immediately ACTH is a very unstable peptide in plasma and should be stored at −20 ° C to prevent artificially low values

Abnormal findings

Increased levels Decreased levels

Addison disease (primary

Cushing syndromeHypopituitarismAdrenal adenoma or carcinoma

Steroid administration

notes

ACTH stimulation test with cosyntropin 13adrenocorticotropic hormone stimulation test

with cosyntropin (ACTH stimulation test, Cortisol stimulation test)

Type of test Blood

Normal findings

Rapid test: cortisol levels increase more than 7 mcg/dL above baseline

24-hour test: cortisol levels greater than 40 mcg/dL

3-day test: cortisol levels greater than 40 mcg/dL

Test explanation and related physiology

This test is performed on patients found to have an adrenal insufficiency An increase in plasma cortisol levels after the infu-sion of an ACTH-like drug indicates that the adrenal gland is normal and is capable of functioning if stimulated In that case, the cause of the adrenal insufficiency would lie within the pitu-itary gland (hypopituitarism, which is called secondary adrenal insufficiency) If little or no rise in cortisol levels occurs after the administration of the ACTH-like drug, the adrenal gland is the source of the problem and cannot secrete cortisol This is called primary adrenal insufficiency (Addison disease), which may be caused by adrenal hemorrhage, infarction, autoimmunity, meta-static tumor, surgical removal of the adrenal glands, or congeni-tal adrenal enzyme deficiency

This test can also be used in the evaluation of patients with Cushing syndrome Patients with Cushing syndrome caused by bilateral adrenal hyperplasia have an exaggerated cortisol eleva-tion in response to the administration of the ACTH-like drug Those experiencing Cushing syndrome as a result of hyperfunc-tioning adrenal tumors (which are usually autonomous and rela-tively insensitive to ACTH) have little or no increase in cortisol levels over baseline values

Cosyntropin (Cortrosyn) is a synthetic subunit of ACTH that has the same corticosteroid-stimulating effect as endog-enous ACTH in healthy persons During this test, cosyntropin is administered to the patient, and the ability of the adrenal gland

to respond is measured by plasma cortisol levels

The rapid stimulation test is only a screening test A normal

response excludes adrenal insufficiency An abnormal response, however, requires a 24-hour to 3-day prolonged ACTH stimu-lation test to differentiate primary insufficiency from secondary insufficiency It should be noted that the adrenal gland can also

be stimulated by insulin-induced hypoglycemia as a stressing

14 ACTH stimulation test with cosyntropin

agent When insulin is the stimulant, cortisol and glucose levels are measured

Interfering factors

Drugs that may cause artificially increased cortisol levels

include corticosteroids, estrogens, and spironolactone

Procedure and patient care

• See inside front cover for Routine Blood Testing

• Administer an IV injection of cosyntropin over a 2-minute period as prescribed

• Measure plasma cortisol levels 30 and 60 minutes after drug administration

24-hour test

• Obtain a baseline plasma cortisol level

• Start an IV infusion of synthetic cosyntropin

• Administer the solution as prescribed for 24 hours

• After 24 hours, obtain another plasma cortisol level

3-day test

• Obtain a baseline plasma cortisol level

• Administer the prescribed dose of cosyntropin IV over an 8-hour period for 2 to 3 consecutive days

• Measure plasma cortisol levels at 12, 24, 36, 48, 60, and 72 hours after the start of the test

Exogenous steroid ingestion

Endogenous steroid production from a nonendocrine tumor

Normal or below normal response (primary adrenal insufficiency)

Addison disease

Adrenal infarction/hemorrhage

Metastatic tumor to the adrenal gland

Congenital enzyme adrenal insufficiency

Surgical removal of the adrenal gland

In Cushing syndrome

Increase above normal response

Bilateral adrenal hyperplasia

Normal or below normal response

Adrenal adenoma

Adrenal carcinoma

ACTH-producing nonadrenal tumor

Chronic steroid use

notes