M. J. Oppenheimer

Pulmonary (venous) air embolism

Abstract Pulmonary (venous) air embolism is a catastrophe which may occur under a variety of circumstances in medical practice. It must be distinguished from arterial air embolism. Our studies in the experimental animal have shown that important factors in determining whether death or survival will occur are: (1) the amount of air which gains admission to the circulation, (2) the speed with which it enters, (3) the position of the body at the time of the embolic accident, and (4) the efficacy of the respiratory excretory mechanism. Death, when it occurs, is due to circulatory obstruction resulting from an air trap in the right ventricular outflow tract. Displacement of the air trap by turning the body into the left lateral position may be life saving even after the right ventricular contractions have become feeble and death seems imminent. Pulmonary air embolism provides a valuable means of studying experimentally the effects of acute right ventricular dilatation produced by obstruction. The rapid and profound electrocardiographic changes which occur under these circumstances include an excellent demonstration of the effects of myocardial ischemia, and also, in some instances, the demonstration of right ventricular conduction defects. The observations of Bayley and LaDue concerning the ischemia-injury pattern are confirmed.

Arterial air embolism.

Abstract Arterial air embolism is an infrequent but often disastrous complication of various thoracic therapeutic procedures. Occasionally it may result paradoxically from air entering the systemic veins and reaching the systemic arteries through a septal defect, or possibly by other mechanisms. The serious manifestations are the result of obstruction by air bubbles of cerebral and coronary vessels, together with spasm of these vessels induced by the irritation of the gas. Animal experiments indicate that air introduced into the coronary circulation, either directly or by injection into the pulmonary vein or left auricle, produces ischemia of the myocardium in areas supplied by involved vessels. The ischemia is demonstrable grossly and by electrocardiographic examination. It may be very temporary, with speedy recovery, or it may persist even after the apparent complete disappearance of the gas bubbles. Death from ventricular fibrillation may result within a very short time after the injection of the air. The distribution of air within the arterial circulation is determined by the principle of air buoyancy. This principle may be made use of in the therapy of arterial air embolism.

THE SAFETY OF INTRAVASCULAR CARBON DIOXIDE AND ITS USE FOR ROENTGENOLOGIC VISUALIZATION OF INTRACARDIAC STRUCTURES

Excerpt The injection of air into body cavities or tissues is a method that has been used for diagnostic purposes (e.g., perirenal insufflation, Rubins test, etc.) and also for therapy (e.g., pneu...

Electrocardiographic Changes Produced by Potassium and Other Ions Injected into the Coronary Arteries of Intact Dogs

Ions injected into the circumflex branch of the left coronary artery of the intact dog produce sequential electrocardiographic changes different from those produced by exposure of the entire heart to these ions. Of all substances tested, the contour of the surface electrocardiogram is most sensitive to potassium. The electrocardiographic sequence of alterations produced by potassium so injected are characteristic and similar to those produced by subtotal and total occlusion of a coronary artery.

Role of the small intestine during emesis

Intestinal activity precedes the act of vomiting when studied in exteriorized loops (7). It is suggested tentatively that this activity is antiperistaltic.

Technic of Transseptal Catheterization of the Left Atrium, Pulmonary Veins, and Left Ventricle in the Dog

The authors have experienced considerable difficulty (3) in attempting to catheterize the left atrium and ventricle of the dog by the transseptal approach beginning from a femoral vein (5, 6). Moreover, other purposes necessitated recording left ventricular pressure without obstructing carotid flow (4). These two facts, a low incidence of success when a catheter was introduced by the transseptal route into the left atrium, starting from a femoral vein, and research projects which demanded uncompromised carotid arteries while recording left ventricular pressures, led to the development of the method presented in this communication. The procedure is easily learned and highly successful in the transseptal approach to the left atrium and ventricle of the dog (1, 2). The site of introduction of the catheter into the venous system is the right external jugular vein. This method should be safe (in this case, for the dog) and technically simple and also give consistent access to the left atrium and ventricle. On ...

Pulmonary Circulation Time in Man at Low Body Temperatures

Summary Pulmonary circulation time is prolonged in humans whose internal temperature is reduced toward 85°F when exposed to low environmental temperatures. It is suggested that diminished output of the right heart is a large factor. Correlations between fall in rectal temperature and prolongation in circulation time exist only when the femoral vein is the site of injection. Shivering shortens circulation time or minimizes prolongation due to hypothermia.

Influence of cathartics on the activity of small intestine

Although the various cathartics influence the amplitude and character of contractions in exteriorized loops of small intestine they fail to change the rate. After administration of magnesium sulfate the feeding responses are suppressed. Of the drugs studied cascara sagrada disturbs activity (motility and feeding responses) least.

The effect of elevated metabolism on rate of intestinal contractions.

1. Thyroid extract, in doses sufficient to elevate metabolism fifty per cent, does not alter the rate of contraction in exteriorized intestinal loops in dogs (Fig. 1) except in a segment just above the ileocecal valve (Fig. 2). 2. Alpha 1, 2, 4 dinitrophenol, in doses sufficient to elevate metabolism over 200–500% does not increase the rate of contraction (Fig. 3) in exteriorized intestinal loops in dogs. 3. Feeding reactions are poor with both these drugs.

Effect of Carbon Dioxide and Other Gases on Electrocardiogram of the Right Ventricle.

Conclusion The rapid intravenous injection of gases or mineral oil in sufficient quantities to replace blood in the right ventricle of dogs will cause the reduction or loss of the initial ventricular deflection of the electrocardiogram in direct leads from the epicardial surface of the right ventricle.