Introduction

Table of Contents

The National Academy of Clinical Biochemistry

LABORATORY MEDICINE PRACTICE GUIDELINES

RECOMMENDATIONS FOR THE USE OF LABORATORY TESTS TO SUPPORT THE IMPAIRED AND OVERDOSED PATIENT FROM THE EMERGENCY DEPARTMENT

Draft Guidelines

We invite all with interest in Laboratory Support for Emergency Toxicology to review this draft Laboratory Medicine Practice Guideline (LMPG).  Your comments, suggestions, additions (including new references) and deletions are welcomed and may be e-mailed to Dr. Alan Wu, Chairman.  Please annotate your responses with the section, subsection and the paragraph in the draft document.  You are an important part of this process; your comments are important.  Please include your name and title with your comments so that you can be properly credited in the final produce.  These Draft Guidelines and suggestions for improvements will be discussed at the 2001 Annual Meeting of the American Association for Clinical Chemistry in Chicago, IL, July 29-August 2, 2001).

Committee

Alan H. B. Wu, Chair
Department of Pathology and Laboratory Medicine, Hartford Hospital, Hartford CT 06102

Larry A. Broussard
Department of Medical Technology, Louisiana State University Medical Center, New Orleans, LA 70112

Robert S. Hoffman
Department of Emergency Medicine, Bellevue Hospital Center, New York, NY 10016

Tai C. Kwong
Department of Pathology and Laboratory Medicine, and Emergency Medicine, University of Rochester Medical Center, Rochester, NY 14642

Charles McKay
Department of Emergency Medicine, Medical Toxicology, Hartford Hospital, Hartford, CT 06102

Thomas P. Moyer
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905

Edward M. Otten
Department of Emergency Medicine, University of Cincinnati Hospital, Cincinnati, OH 45267

Shirley L. Welch
Department of Pathology, Kaiser Permanente Regional Laboratory, Clackamas, OR 97015

Paul Wax
Emergency Medicine, University of Rochester Medical Center, Rochester, NY 14642

 

Introduction

This is the ninth in the series of Laboratory Medicine Practice Guidelines (formerly Standards of Laboratory Practice, SOLP) sponsored by the National Academy of Clinical Biochemistry (NACB).  An expert committee of emergency department (ED) physicians and clinical laboratory medicine toxicologists was assembled and prepared recommendations on the use of clinical laboratory tests to support the drug-impaired, or overdosed patient, or those exposed to various substances (clinical toxicology).  Particular reference is made to the management of these patients who present to hospitals and emergency departments.  Excluded from these discussions were drug testing conducted for the workplace, forensic and medical examiner toxicology, athletic drug testing, and testing for various compliance programs (criminal justice, psychiatric, physician health, etc).  Many of these other programs are guided by other recommendations and regulations, such as the Substance Abuse and Mental Health Services Administration, the American Academy of Forensic Sciences, International Olympic Committee, etc.  Recommendations for detection of drugs from newborns exposed during the intrauterine period were discussed in a previous NACB SOLP (1) and will not be repeated.  Some of the recommendations contained herein are specifically directed towards manufacturers of immunoassay reagents.  It is hoped that by documenting a clinical need for modified immunoassays, manufacturers would be willing to develop these new assays.

Data from the Drug Abuse Warning Network (DAWN) have shown that a significant number of emergency department visits are associated with the presence of alcohol and drugs as indicated by a positive laboratory test (2). Table 1 lists results for the first half of 1998. The statistics refer to patients aged 6 to 97 years, whose primary presenting problem was associated with drug use, but was not necessarily the sole reason for the ED visit.  This database is also not a measure of drug prevalence in the general population.  Moreover, these statistics are based on self-reporting by the user, and were not necessarily confirmed by laboratory testing.  Some drugs (e.g., cocaine and heroin) may have a higher association with ED visits than others because they result in greater acute toxicity.  Alcohol is not separately tabulated by DAWN. However, the National Hospital Ambulatory Medical Care Survey estimates an alcohol incidence of 27% of ED patients (3).   Together, these data indicate that nearly thirty million ED visits per year are associated with some form of drug use.

Table 1. Estimated Number of ED Drug Episodes and Drug mentions, January-June, 1998.a 

Drug or Class

% of Total ED Visits

Alcohol in combination

0.024

Cocaine

0.191

Heroine/Morphine

0.086

Analgesics (acetaminophen, aspirin, ibuprofen, propoxyphene, oxycodone, hydrocodone)

0.108

Benzodiazepines (alprazolam, diazepam, lorazepam, clonazepam, triazolam)

0.067

Marijuana/hashish

0.084

Tricyclic antidepressants (amitriptyline, doxepin, imipramine)

0.011

Barbiturates (phenobarbital, over-the-counter sleep aids)

0.013

Amphetamines (amphetamine and methamphetamine)

0.026

Phencyclidine

0.005

Lithium

0.004

Lysergic acid diethylamide

0.004

 aFrom the Office of Applied Statistics, the Drug Abuse Warning Network, 1998.  Total ED visits: 44,836,000; number of drug episodes: 272,770 (0.61%) , drug mentions: 493,096 (1.1%).

There are other substances that can contribute to significant acute clinical problems for which the laboratory might play an important role.  Some of these are tabulated each year by the Toxic Exposure Surveillance System (TESS) of the American Association of Poison Control Centers (4).  In 1998, for example, there were a reported 13,000 exposures to organophosphates, 18,000 to rodenticides (anticoagulants), 13,000 to heavy metals, 17,000 to carbon monoxide, and 2,000 to toluene.  It should be noted that the majority of these exposures were managed in a non-health care facility, usually at the site of exposure.

These guidelines cover five major parts: recommendations for drug testing to support emergency department toxicology, analytical and reporting issues for drugs of abuse testing, breath alcohol analysis, serum testing of ethyl alcohol and other volatiles, and assays for substance abuse and exposure.  Each of these topics opens with some background information, followed by the recommendations themselves, and discussion of the rationale for each recommendation.  These recommendations will be presented in open forum during Edutrak Sessions at the American Association for Clinical Chemistry Annual Meeting on August 1st -2nd, 2001 in Chicago, IL, and possibly the American College of Medical Toxicologists in September  2001 in Montreal.  Participants to each meeting will be able to discuss the merits of each recommendation.  Each recommendation will be graded according to the degree of consensus reached by the discussants of these conferences.  Revisions to these recommendations and the discussion by participants will be made prior to the submission of the final guideline for publication.

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