Abstracts of Recent Publications by the Guthrie Clinic Staff

Abstract

The Vienna Physicians’ Society recently had as a visiting lecturer Dr. Donald Guthrie of Sayre, Pa. He described the mechanism of the air embolisms that may occur in the course of a surgical intervention, especially if the thyroid is involved. Arterial embolism is more dangerous than a venous embolism, since it may lead to embolism in the brain or in the coronary arteries. In the first rank of blood vessels, predisposed to venous embolism, are those veins which are strongly intergrown with the deep cervical fascias. Fatal air embolism in man was first described in 1818, although in medieval times animals were put to death by intravenous insufflation of air. Fatalities from air embolism depend on mechanical and biologic factors; the blood becomes frothy and is forced back into the veins by the systole, a small amount of blood reaching the lungs and the left ventricle. The anemia that ensues in the region of the fourth ventricle (a vital center) causes cessation of respiration. Death occurs only if the amount of entering air exceeds a certain magnitude; the patient may be saved by timely artificial respiration. Small quantities of air cause dyspnea and a fall in blood pressure. Exophthalmic goiter patients are in greater peril if an air embolus appears than patients with other forms of thyroid disease. Diagnosis is easily established by the typical sounds that accompany entrance of air into the vascular system: a hissing sound and a “mill-wheel sound”; the latter is audible at a distance of 1 or 2 meters. Gas bubbles are often observed on the retinal blood vessels. The speaker has observed four embolic accidents, one fatal, which occurred during thyroidectomies. The best treatment is a speedy prophylactic ligature of the exposed vein; one should take care not to apply too great a number of Kocher’s forceps. In operation for recurrent goiter the cicatrices are a great source of annoyance. In case of collapse the immediate indication is artificial respiration by means of oxygen and carbon dioxide, since the impairment of respiration precedes the cardiac dysfunction. Intracordial injection of a 2 per thousand solution of epinephrine can also be tried. In the general discussion of Dr. Guthrie’s paper, Professor Denk said that among 378 thyroidectomies observed by him during the past four years there had been three cases of embolism, two mild and one fatal. Professor Ranzi reported similar experiences. He said that in most instances air embolism runs a favorable course. Should an embolic accident occur the patient should immediately be shifted and the field of operation covered with cloths or gauze and common salt solution. Professor Finsterer usually performs a thyroidectomy with the patient in Trendelenburg’s position. He considers this the best prophylactic measure that can be taken against embolism. The drawing off of the intruding air by means of a glass tube or of a ureteral catheter advanced from the cubital vein toward the heart is recommended by many. Professor Werkgartner has gone over the necropsies for all the years since 1919 at the Institute of Legal Medicine. Since that year fifty cases of fatal embolism have been reported. Included in this number are embolic accidents connected with induced abortions and puncture wounds. In fatal cases Professor Werkgartner observed from 70 to 120 cc. of air in the right side of the heart. At necropsy it is often most difficult to determine the exact point at which the air entered. It is usually apparent that the frothy blood has been forced by the systole into the pulmonary artery and the larger veins and that relaxation of the heart has caused it to recede, so that blood no longer reaches the periphery of the lungs.