four RNA extraction methods for the detection of small round structured viruses in faecal specimens. J. Virol. Methods. 57:195-201.

45. Schwab, K.J. et al. 1997. Use of heat release and an intemal RNA standard

control in reverse transcription-PCR detection of Norwalk virus from stool samples. J. Clin. Microbiol. 35:511-514.

46. Atmar, R.L. et al. 1995. Detection of Norwalk virus and hepatitis A virus in shellfish tissues with the PCR. Appl.

Environ. Microbiol. 61:3014-3018. 47. Le Guyader, F. et al. 1996. Detection

and analysis of a small round-structured virus strain in oysters implicated in an outbreak of acute gastroenteritis. Appl. Environ. Microbiol. 62:4268-4272.

Editorial

The Non-Physician Expert in Medical Malpractice Litigation Paul D. Ellner, Ph.D. Professor Emeritus Departments of Microbiology and

Pathology College of Physicians & Surgeons Columbia University New York, New York 10033

Medical malpractice litigation is an interesting and challenging field for the biomedical scientist. It offers the oppor- tunity to apply his or her specialized knowledge and experience in the legal arena by participating in the defense of a physician unjustly accused of injuring a patient or in supporting the claim of a patient who has been harmed by the negligence of a physician.

Medical malpractice litigation revolves around the theory of negligence. To prove negligence the plaintiff must establish: (i) a duty owed to the patient by the treating physician; (ii) a breach of that duty; (iii) injury or damage; and (iv) proximate cause. Breach of the duty owed to the patient requires proof of the acceptable standard care, a standard that has been defined as "what the reason- able person of ordinary prudence would do under like circumstances."

With the possible exception of limit- ed circumstances that are self-evident, known as res ipsa loquitor, an expert witness is required to define for the court the appropriate standards of care, and possibly testify as to how the defen- dent physician's actions conformed or deviated from these standards.

Federal Rule of Evidence (ER.E). 702 states: If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evi- dence or to determine a fact in issue, a witness qualified as an expert by knowl- edge, skill, experience, training, or edu-

cation may testify in the form of an opinion or otherwise.

Expert witnesses asked to testify in medical malpractice cases are usually physicians who specialize in a medical discipline related to the case. However, biomedical scientists who are not physi- cians can often provide cogent and relevant information and/or testimony. Qualifications to be accepted as an expert witness usually include a doc- toral degree in a basic medical science, teaching experience in a medical facility, publications in scientific journals, and membership in professional societies. Clinical chemists, pharmacologists, physiologists, microbiologists, immu- nologists, and others may furnish valu- able input by acting as a testifying expert or as a litigation consultant.

The testifying expert plays an active role in the legal controversy. He/she will be examined by the opposition at deposition and possibly later at trial. All of the expert's activities relating to the case, as well as his or her work prod- ucts, are discoverable. The expert's effectiveness as a witness during trial will be as much determined by his or her demeanor and presentation in court as by the factual material presented.

Since 1993, many courts have adopted the Daubert standard which holds that scientific testimony must be screened by the trial judge to assure its relevance and reliability. The Federal Judicial Center's Reference Manual on Scientific Evidence, intended as a guide for judges, lawyers, and experts, asks a fundamen- tal question: Is the expert qualified?

The opposition will try to negate or at least lessen the impact of the expert's testimony by raising the question of his/ her qualifications. A serious attempt will

be made to disqualify the non-physician expert on the basis of a lack of clinical experience, training, or education.

The litigation consultant who is not called as an expert witness is immune from these challenges. Like a coach at an athletic event, he/she does not partic- ipate in the contest but remains on the sidelines advising and counseling. The consultant is not subject to examination by the opposition, and his or her activi- ties and work products such as reports to the attorney, are not subject to discovery.

The following three cases illustrate how a non-physician expert effectively functioned as a consultant in mal- practice actions:

Case 1. The plaintiff cut his leg on a fence while chasing his horse. The emergency room physician treated the wound and sent him home. He returned several hours later in great pain, and was again treated by the physician. The following day the plaintiff consulted a surgeon who admitted him to the hospi- tal and performed extensive surgery on the man's leg. The surgeon remarked that the emergency room physician had not properly cleaned and drained the wound. The patient sued the emergency room physician for malpractice. Acting as a consultant for the defense, the non- physician expert, familiar with minor surgical procedures, reviewed the emergency room physician's and nurse's notes, and was able to advise the defense attorney that the treatment provided by the physician conformed to or exceeded the standard of care in such cases. The expert relied upon several textbooks of surgery.

Case 2. A women fell and injured her knee. Following treatment by a physi-

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cian in the emergency room of the local hospital, she subsequemly developed a severe infection that over the course of several years involved the bones of her leg. The non-physician expert acting as consultant for the plaintiff's attorney, was able to suggest that the treating physician closed the wound prematurely which predisposed to the infection. The consultant's opinion was based upon his review of the standards of care as pub- lished in several textbooks of surgery.

Case 3. An infant developed severe seizures several hours after delivery, and the obstetrician was sued for per- mitting prolonged labor that compro- mised the oxygen supply of the fetus resulting in brain damage. The non- physician expert, acting as consultant for the defense, reviewed the mother's prenatal history and advised the defense attorney that the infant's seizures could

have been caused by a specific infec- tious disease contracted by the mother during her pregnancy.

In the first two cases, the consultant dealt with the standard of care; the third case was concerned with proximate cause.

An expert's opinion may be based upon his/her personal experience, experiments that he/she has conducted that directly relate to the case, or on scientific articles published by others (ER.E. 703). In some instances stan- dards of care have been published by professional organizations, and the non- physician expert may refer to and rely upon such sources. The Hearsay Rule (ER.E. 803) exempts material from learned treatises relied upon by the expert witness in direct examination. The rule notes that "statements con- tained in published treatises, periodicals, or pamphlets on a subject of...medicine,

or other science or art, established as a reliable authority by the testimony or admission of the witness.., may be read into evidence . . . . "

Non-physician biomedical scientists explaining aspects of anatomy, bio- chemistry, pharmacology, immunology, microbiology, pathology, or other basic medical sciences can be very effective as testifying experts for either plaintiff or defense. It is the writer's opinion that for psychological rather than legal reasons, it is easier for a non-physician expert to defend or justify a physician's actions than to disparage or criticize a doctor's treatment. Hence, non-physician experts dealing with questions relating to standards of care, especially when working for the plaintiff's attorney, may be more useful as litigation consultants.

Case R e p o r t

MoraxeUa catarrhalis Bacteremia Fernando Garcia-Garrote Sc. D. Ana Menasalvas, M.D. Lucifi Martfnez-S~inchez, Pharm. D. Emilia Cercenado, Pharm. D. Luis Alcal~i, Pharm. D. Emilio Bouza, M.D., Ph.D. Servicio de Microbiologia Clinica y

Enfemedades lnfecciosas Hospital General Universitario

"Gregorio Mara~on" 28009 Madrid, Spain

Moraxella catarrhalis is a sapro- phytic microorganism of the upper respiratory tract that has received con- siderable interest during the past years as a respiratory tract pathogen in pedi- atric patients and immunocompromised adults (1). It has also been of interest to microbiologists for its taxonomic posi- tion. It was originally classified in the Neisseria and Branhamella genera. However, it rarely causes systemic infections (2,3). We report a case of M. catarrhalis bacteremia in an immunosuppressed patient.

A 74-year-old woman was admitted to the hospital because of a 1-month history of weight loss, fever, asthenia,

and abdominal pain. On admission, the patient was cachectic and presented with liver and spleen enlargement. A chest Xray demonstrated a bilateral lung infiltrate with pleural effusion and multiple nodular images. The abdominal CT scan showed retroperitoneal lymph node enlargement and multiple, low density, space-occupying lesions in the liver. A presumptive diagnosis of carci- noma was established although the pri- mary tumor was not found. Three blood cultures were obtained and empirical therapy with cefotaxime was instituted. The clinical status of the patient deteri- orated and she died one week after admission, three days after the isolation of ~-lactamase-positive M. catarrhalis from all three blood cultures.

Discussion M. catarrhalis is a non-motile,

gram-negative, oxidase-catalase-posi- tive diplococcus. It grows well on both blood and chocolate agar at 35°C either in the air or in an atmosphere of 5 to 7% CO2. After 18 to 24 h, the colonies are small, round, entire, whitish-gray, opaque, and smooth. Nitrate reduction,

Clinical Microbiology Newsletter 19:23,1997 ©1997 Elsevier Science Inc.

inability to produce acid from carbohy- drates and tributyrin hydrolysis allows differentiation from microorganisms of the genus Neisseria. DNAse production distinguishes M. catarrhalis from other Moraxella species.

M. catarrhalis has frequently been associated with a variety of clinical dis- eases involving the respiratory tract, and in the last two decades it has been implicated in a wide variety of human infections ranging from systemic, life- threatening diseases to acute, localized processes (2-7).

M. catarrhalis bacteremia is uncom- mon and its incidence cannot be esti- mated with accuracy, but a recent literature review reports 58 cases since 1925 (7). Most cases of M. catarrhalis bacteremia have been described in patients with chronic underlying condi- tions. Neutropenia, immunoglobulin abnormalities, and hematologic malig- nancies contribute to increased patho- genicity of this microorganism, thereby predisposing the individuals to more severe infections like bacteremia (2,3,7). However, fatal cases have also

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