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The Harmful Effects and Treatment of Coronary Air Embolism During Open-Heart Surgery

1972; Elsevier BV; Volume: 14; Issue: 1 Linguagem: Inglês

10.1016/s0003-4975(10)65197-1

1552-6259

Claire Justice, John K. Leach, W. Sterling Edwards,

Cardiovascular and Diving-Related Complications

Residual coronary air embolism after heart-lung bypass is an occasional cause of poor myocardial contractility and low cardiac output.To quantitate the amount of myocardial depression from given amounts of air and to explore the most efficient way to remove coronary air, 19 dog experiments were carried out.During extracorporeal circulation, balloons were inserted into the right and left ventricular cavities to measure isovolumetric myocardial contractility.Small amounts of air injected into the aortic root caused transient myocardial depression with rapid recovery.Repeated injections of small amounts of air produced an additive effect-more depression and slower recovery with each injection.A pure peripheral vasoconstrictor was not as effective as an inotropic drug such as ephedrine or isoproterenol in improving contractility.By far the most effective method of removing air from the coronary arteries and improving contractility and color of the myocardium was to increase the perfusion flow rate for one minute to one and one-half to two times normal.Large amounts of foam appeared from the coronary sinus when flow rates were increased, and hearts intractable to electrical defibrillation became pink and responded to a single shock.oronary air embolization has long been a recognized hazard of openheart operations, and numerous techniques have been devised for C its prevention, including ventricular suction vents, aortic needle vents, induced ventricular fibrillation, and induced mitral insufficiency.It has been established that a small amount of air in a major coronary artery can cause a serious depression of ventricular function [l-123.It has beengenerally assumed that the presence of coronary air is not of serious consequence if it occurs during artificial support of the circulation by heart-lung bypass and that it will be forced on through by the artificially maintained systemic pressure, causing little permanent damage.Therefore, this study was devised (1) to quantitate the effects of measured amounts of coronary air on myocardial contractility during bypass;(2) to determine the best