Joseph H. Davis

Pathophysiologic observations in prehospital ventricular fibrillation and sudden cardiac death.

In order to better understand the problem of prehospital sudden cardiac death (SCD) two groups of individuals were studied. One group was monitored by rescue squads during attempted rescue. These subjects were defibrillated from prehospital ventricular fibrillation (VF) and hospitalized if they survived or autopsied if they could not be resuscitated. The second group were SCDs which were witnessed and described by observers. Detailed past histories of both groups were collected, and either clinical or autopsy diagnoses were obtained.On the day of death or VF, one quarter reported new symptoms (primarily chest pain and dyspnea) preceding collapse by more than 30 minutes, one quarter reported symptoms lasting from 1 to 30 minutes, and one half collapsed instantaneously or within 1 minute of acute symptoms. A history of old myocardial infarction (MI) was present in 41% and of angina pectoris in 54%, and 27% reported new or changing symptoms within four weeks.In defibrillated survivors, “would-be SCDs,’ electrocardiographic (ECG) changes of acute myocardial infarction (AMI) or ischemia were nearly three times more frequent than changes detected histologically in SCDs, and in the former involved predominantly the anterior wall in contrast to the inferior wall in most autopsied deaths. This disparity implicates acute myocardial lesions, particularly of the anterior wall, in the majority of SCDs.Acute coronary lesions were found in 58% of SCDs autopsied. Most of these were ruptured plaques although almost one fifth of all autopsied SCDs had thromboses without intimal rupture. Severe chronic multivessel stenosis was present in most subjects, although 15% had only disease of a single vessel and in these, the left anterior descending (LAD) or left main coronary artery were involved in three quarters.The SCD population may be subgrouped into those with recent MI, those with only myocardial ischemia, and those with no detectable myocardial change. When rescuers were able to monitor prehospital SCDs, VF was found in the majority; however, 28% did have other terminal rhythms.

Preventable trauma deaths: Dade county, Florida

We reviewed 1,201 trauma deaths that occurred in Dade County, Florida, in 1982 in order to evaluate the need for an organized trauma network. There were 715 deaths (59.5%) at the scene. Of the remaining 486 patients who were transported to hospitals for treatment there were 240 central nervous system (CNS) deaths and 246 non-CNS deaths. Fifty-two (21.1%) preventable non-CNS trauma deaths were identified out of the 246 non-CNS deaths. The lack of an appropriate surgical procedure or a delay to surgery accounted for 82.7% of the preventable deaths. The preventable non-CNS death rate was 12.1% at the then functional Level I hospital and 26.4% at the other 22 hospitals (p less than 0.01). The ISS scores were similar for both the functional Level I hospital and the other hospitals. A trauma network involving seven hospitals is currently being established in Dade County, Florida. Applying the 1982 data to these hospitals reveals a preventable non-CNS death rate of 12.1% for the Level I hospital, 21.5% for the six planned Level II hospitals, and 30.0% for the other 16 hospitals. We conclude that: the severely injured should be triaged directly to trauma centers, and there is a need in Dade County, Florida, for an organized trauma system.

Intramedullary Pressure and Pulmonary Embolism of Femoral Medullary Contents in Dogs during Insertion of Bone Cement and a Prosthesis

Femoral medullary pressures and pulmonary embolization of medullary contents during the insertion of cement and a medullary rod in greyhounds were studied. In three animals, insertion of cement into the femoral shaft resulted in medullary pressures of between 290 and 900 torr and the appearance of medullary contents in the lungs within ten to 120 seconds. In five other animals, pulmonary embolization was not detectable when the rise in femoral medullary pressure was prevented by drilling a hole distal to the cemented area.

Fatal injuries to bicyclists: the experience of Dade County, Florida

Among 173 fatally injured bicyclists, the head or neck was the region most seriously injured in 86%. The frequency of injury to the head and neck region and the frequency of nonsurvivable (AIS 6) injury were highest among the cases aged 16 years or less. Vertebral fractures occurred most often in the highest cervical vertebra (C1) and progressively less often in lower vertebrae. The relationship between vertebral position and fracture likelihood is approximately log linear. Bicyclists with a relatively long time from injury to death tended to be older persons with survivable injuries. They often died from complications (pneumonia, pulmonary embolus) rather than directly from their injuries.

The Investigation of Electrical Deaths: A Report of 220 Fatalities

We present the results of our investigation of 220 electrocutions. The ratio of high voltage to low voltage electrocution is found to be nearly 1:1. Further, in low voltage electrocution deaths electrical burns were absent in over 40% of the cases. Our approach to the investigation of possible electrocution, including equipment analysis, is discussed.

Diagnostic and Therapeutic Problems of Parathion Poisonings

Abstract Because poisoning by parathion may simulate other more common diseases, its early diagnosis is not always easy. The ultimate outcome of such an intoxication is very largely dependent upon,...

Effect of Chronic Exposure to Ultrasonic Aerosols on the Lung

Exposure for six hours to aerosols produced by ultrasonic nebulizers has been shown not to affect adversely the lungs of experimental animals. In order to evaluate the effects of long term exposure, 16 puppies were exposed to ultrasonic aerosols of normal saline solution or distilled water for 72 hours. Pathological changes compatible with severe bronchopneumonia were seen in all 8 animals exposed to saline; only 2 puppies exposed to distilled water had obvious pulmonary lesions. No significant alteration in pulmonary surfactant activity or deflation pressure volume curves were demonstrated. We conclude that continuous wetting of the lung with a high output of ultrasonic aerosol may be deleterious when used for prolonged periods. The exact time necessary to produce these lesions with various fluids remains to be determined. It seems reasonable to speculate, however, that the more hypertonic the fluid the more rapidly these lesions will develop.

Can Sudden Cardiac Death be Murder

A problem faced by police, medical examiners, and prosecutors is the course of action to be pursued when a criminal act results in emotionally precipitated death in the absence of physical injury or contact. The determination of proximate causation may be difficult if there is no autopsy evidence of life-threatening physical trauma nor any historical evidence of physical contact between the victim and the assailant. The usual circumstance is a robbery or burglary during which, or shortly after, a victim collapses. The victim is usually found to be suffering from severe coronary atherosclerosis and its complications.

Death and Injury Caused by Methyl Bromide, An Insecticide Fumigant

Methyl bromide (MeBr) is used as an insecticide fumigant. Four deaths and three recent hospitalizations have resulted from exposures to MeBr in Dade County, FL. Six cases occurred during burglaries of tented houses over a nine-month period. In four lethal exposures, the symptoms of nausea, vomiting, and malaise preceded fulminant respiratory failure. Two of these also had seizures, delirium, and agitation. Serum or plasma bromide ion levels ranged from 40 to 583 mg/L. Pulmonary edema, hyaline membranes, and hemorrhagic alveolitis were present at autopsy along with varying degrees of cerebral edema. The nonlethal exposures resulted in symptoms of conjunctival irritation, headache, or nausea. Plasma bromide concentrations varied between 17.5 and 321 mg/L. Methyl bromide characteristics, use, morbidity, and mortality in Florida during the past 25 years are reviewed. Remedies for illegal entry are proposed.

Spontaneous Births into Toilets

Since inception of the Dade County Medical Examiner Department in 1956 and the end of 1982 a total of 18 spontaneous births into toilets were investigated. A retrospective review of these cases revealed a high degree of maternal denial of pregnancy and refusal of responsibility for the fetus by primiparous mothers of term births, the instances of most questionable manner of death. A consideration in the examination of these natal deaths should be investigation of maternal postnatal behavior along with the circumstances of birth and autopsy findings.