Louis Cannon

Continuous monitoring of mixed venous oxygen saturation in septic shock

Fiberoptic pulmonary artery catheters provide a practical method for continuously measuring the amount of oxygen in mixed venous blood. To characterize the usefulness of mixed venous oxygen saturation in managing patients with sepsis, we performed serial hemodynamic measurements on 20 patients with documented septic shock. There was a highly significant positive correlation between increases or decreases of 5% or more in mixed venous oxygen saturation and corresponding changes in oxygen delivery (r = 0.95) and oxygen consumption (r = 0.96). Mixed venous oxygen saturation less than 65% was clinically unacceptable in patients with sepsis and was associated with a poor prognosis. In this study, measurement of mixed venous oxygen saturation was a valuable predictor of survival in patients with septic shock and provided a means of continuously monitoring the status of tissue oxygenation.

Diphenhydramine-induced toxic psychosis

A 24-year-old man presented to the emergency department with acute anticholinergic symptoms, hallucinations, and bizarre behavior following a large ingestion of diphenhydramine (Benadryl). Because of the large number of nonprescription preparations containing this antihistamine, similar ingestions are becoming increasingly frequent. Minor anticholinergic side effects associated with diphenhydramine are general medical knowledge. The effects of overdosage are less well known. The clinical presentation of toxic psychosis, its differential diagnosis, and its subsequent treatment are discussed.

Repetitive doses of activated charcoal in the treatment of poisoning

Activated charcoal has found a renewed role in the management of overdosed patients. Routinely administered to reduce the gastrointestinal (GI) absorption of many drugs, growing evidence indicates that repeated doses of charcoal also may enhance drug elimination. Some drugs are excreted into the bile or gastric fluids (phencyclidine, digoxin) and are reabsorbed. Other drugs (theophylline, phenobarbital) can diffuse from the plasma into the lumen of the GI tract. Activated charcoal is administered at regular intervals to sequester these toxins in the GI tract, eventually causing their excretion in feces. This article reviews the evidence for the safety and efficacy of repetitive charcoal therapy. While supportive management remains the mainstay of therapy in poisoned patients, activated charcoal is inexpensive, effective, simple to administer, and may obviate the need for more invasive methods of toxin removal.

Magnesium levels in cardiac arrest victims: Relationship between magnesium levels and successful resuscitation

Multivariate analysis was performed to evaluate significant differences between electrolytes, serum magnesium, and successful resuscitation in cardiac arrest victims in a prospective controlled study. Twenty-two cardiac arrest victims having ventricular fibrillation or tachycardia, electromechanical dissociation, or asystole were compared with 19 matched controls with no ventricular arrhythmias. Of the control group, one was hypermagnesemic (5%), 17 normomagnesemic (90%), and one hypomagnesemic (5%). In the arrest group, eight were hypermagnesemic (36%), nine normomagnesemic (41%), and five hypomagnesemic (23%). Thirteen of 22 cardiac arrest victims (59%) had an abnormal serum magnesium level. All hypermagnesemic and hypomagnesemic patients expired (100%). In the normomagnesemic group, four out of nine (44%) were successfully resuscitated. A positive correlation was identified between normomagnesemia and successful resuscitation (P less than .01). There was no correlation between other electrolytes and successful resuscitation (P greater than .05).

Teaching research in the emergency medicine residency curriculum

Research in emergency medicine is a necessary component for the growth and development of the academic discipline. Although the need exists for competent physician investigators, most graduates of emergency medicine residencies have had little structured education in research design or methodology. This is particularly true in community hospital programs with little funding allocated to research, limited facilities, and few staff members actively involved in research. Our purpose is to describe a research curriculum designed to operate within a community-based residency program. This curriculum identifies a detailed set of educational objectives in research techniques with the expectation that on completion of the residency program, the resident will be able to critically evaluate medical literature and independently design a research project. We have developed a specific plan for meeting these objectives with coordinated seminars, readings, journal clubs, research projects or exhibits, and professional conferences. We suggest some practical methods of motivating residents and attending staff to pursue clinical investigation.

A geriatrics curriculum for emergency medicine training programs

The growing number of elderly in the United States will continue to increase the demand for emergency services. Although the emergency medicine core curriculum, as defined by the American College of Emergency Physicians, requires mandatory training in pediatrics, there is no mention of geriatric care. A special body of knowledge regarding normal aging as well as the special presentation of disease in the elderly is required to provide optimum care for the aged patient. We present an integrated geriatric curriculum designed to operate within a three-year emergency medicine residency program. This curriculum identifies specific educational objectives for training in geriatric emergencies that can be summarized as follows: identify those impairments and functional disorders that often complicate diagnosis and therapy; acquire an understanding of how physiologic changes in aging affect normal laboratory and radiologic values; develop knowledge of drug side effects and interactions in this population; understand and treat the group of disease peculiar to the elderly; recognize diseases and injuries that present a different clinical picture in old age; and differentiate and treat common psychosocial emergencies in the elderly. These educational objectives are further defined using a specific interlinked framework of didactic presentations, journal clubs, case conferences, therapeutic audits, formal rotations, and consultants. This format will provide valuable educational experiences for the emergency medicine resident and may strengthen positive attitudes toward geriatric medicine.

Persistent hiccups as an unusual manifestation of hyponatremia

In two patients, persistent hiccups were an unusual presenting manifestation of hyponatremia. Persistent hiccups occur in a variety of serious diseases, including metabolic and electrolyte disorders. They may cause the victim significant distress and may be refractory to most treatments. Hiccups lasting more than 24 hours require investigation for an underlying organic etiology, with hyponatremia included in the differential diagnosis.

HYPOKALEMIC PERIODIC PARALYSIS

Generalized motor weakness is a common complaint in the emergency department and has a wide differential diagnosis that includes both organic and infectious etiologies. We report the case of a previously healthy young man with symptoms of muscular paralysis and associated hypokalemia. The clinical presentation of hypokalemic periodic paralysis, its differential diagnosis, and pertinent physical findings are discussed.