When four forensic pathologists tell physiologists about the deaths that puzzle them, they will do so with the hope of sparking laboratory research to help define the cause of these deaths and prevent more of them.

The four pathologists, all medical examiners and professors, will present their insights, as well as uncertainties, about deaths that happen as struggling individuals are arrested, as infants sleep in their cribs, and following years of drug abuse. By sharing these experiences with physiologists, the medical examiners hope to spur research to clarify how these deaths occur, how to identify them during autopsy, and how to prevent them.

The Physiology in Focus program, “Forensic Medicine,” will take place at the 120th annual meeting of The American Physiological Society (APS), which coincides with Experimental Biology 2007, a conference expected to attract 12,000 scientists from across the globe. The session will take place at 8 a.m., Tuesday, May 1 in Ballroom B of the Washington Convention Center.

Cause of death can be murky
“The portrayals of medical examiners on television and in movies and books follow the requirements of dramatic construction,” noted Gregory G. Davis, M.D., who will lead the session. In these stories, medical examiners, for instance, nail down the precise cause of death and the exact time. Or they pinpoint the number of pills a person took before dying of an overdose. Such precise pronouncements are often not possible for the real life medical examiner.

In real life, the cause of death may not be entirely clear, and this is especially difficult for families when the deceased is young, said Davis, who is an associate professor at the University of Alabama at Birmingham and associate Jefferson County coroner and medical examiner. One of the hardest things Davis must do is tell a family he does not know why their child died, even after performing an autopsy.

The speakers at the Forensic Medicine symposium and the cases they will discuss are as follows:

Deaths associated with police restraint or force
J. Keith Pinckard, M.D., Ph.D., an assistant professor at the University of Texas Southwestern Medical Center and Southwestern Institute of Forensic Science, both in Dallas, will discuss sudden deaths that occur when police restrain or use force to subdue an individual who may be violent or highly agitated, as in the case of cocaine-induced agitated delirium.

These deaths are likely due to a combination of the restraint and force used and the individual’s physiological condition. Restraints include choke holds, carotid sleeper holds and hog-tying. Force includes the use of Tasers, a device to zap uncooperative individuals with electrical pulses of high voltage and low amperage. In some cases, deaths have occurred after both restraint and force were used together and in other cases when either restraint or force was used.

Research is needed to help explain what factors contributed to these sudden deaths. It is likely they are due to a complex interaction of factors such as intoxication, mental illness, or health status, combined with a violent, even if brief, struggle.

Deaths due to asphyxia
Amy C. Gruszecki, D.O., an assistant professor at the University of Texas Southwestern Medical Center and the Southwestern Institute of Forensic Science, both in Dallas, will discuss sudden deaths due to asphyxia, including drowning, suicide by hanging and sudden infant death syndrome (SIDS).

After researchers noticed that infants who sleep on their backs had much lower death rates than those whose parents placed them on their stomachs, pediatricians recommended infants sleep on their backs. SIDS deaths dropped 40 percent. However, SIDS remains a problem and little is known about why it strikes some children and not others. In at least some cases, research has already shown that some infants have immature development of nerve pathways in their brains. More research is needed to be able to identify SIDS at autopsy and to prevent more of these deaths.

Deaths associated with drug abuse
People who have a history of chronic abuse of cocaine and opiate drugs have an increased risk of dying, even when they have no drugs in their system, noted Dr. Davis, who will lead this discussion. Research shows that chronic cocaine use increases the risk of blood clots, hardening of the arteries, and thickening of the heart muscle, among other effects. More research could help identify the physiological changes that could lead to a sudden death so that these deaths could be identified when they happen and possibly be prevented.

Jeffrey M. Jentzen, M.D., of the Milwaukee County Medical Examiner’s office and a professor at the Medical College of Wisconsin, also in Milwaukee, will look at genetic variations accounting for differences in metabolic rate among individuals. Because people metabolize pills at different rates, for example, medical examiners are unable to precisely determine at autopsy how many pills the victim took.

When prescribing drugs, it is important for the doctor to know if the patient is a slow metabolizer, because these patients may inadvertently overdose on drugs such as methadone, which remains in the body for a relatively long time. Recent research suggests that up to 60 percent of methadone deaths may be related to genetic variations that result in varied metabolic rates. Pharmacogenomic testing at autopsy could become a major tool in explaining some of these sudden deaths.

Source: American Physiological Society.