Archives des maladies du coeur et des vaisseaux
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Arch Mal Coeur Vaiss · Mar 1984
[Prevention of gas microemboli during cardiac surgery. Numerical control of cardiac cavity purging by an ultrasonic detector].
Despite all precautions taken by cardiac surgeons to eliminate air remaining in the cardiac cavities and pulmonary veins at the end of cardiopulmonary bypass, many micro bubbles probably remain and pass into the systemic circulation with a risk of deteriorations of cerebral or myocardial function. Over the last four years we have used ultrasound to try to prevent the risk of preoperative gas microemboli: the machine is equipped with a detector (a quartz oscillator coupled to a piezoelectric transducer emitting a continuous beam of ultrasound at a frequency of 5 Mhz) which allows the following variables to be determined: the time interval from the onset of detection, the total quantity of bubbles (arbitrary units) in the examined regions, the quantity of bubbles detected over a given time interval which can be adjusted from 15 to 120 seconds. The passage of bubbles is also indicated by light and sound alarms. ⋯ Therefore, after cardiopulmonary bypass, and despite all efforts at purging the air, we showed that numbers of microbubbles were ejected into the ascending aorta for a variable period of time: only some of them were eliminated by active aspiration through a trocar placed distal to the periaortic probe. The right coronary ostium was poorly protected against microbubbles because of its anatomical situation (6 cases in this series). We therefore established a protocol for the use of this apparatus to aid the purging of the cardiac cavities and pulmonary veins before stopping cardiopulmonary bypass: the manoeuvres, guided by the ultrasound probes, are performed before the left ventricle is allowed to eject blood into the ascending aorta.(ABSTRACT TRUNCATED AT 400 WORDS)