RESUMEN
BACKGROUND: Open heart surgery is associated with important risk of cerebral and peripheral organ dysfunction, attributed in part to microbubbles generated in or not eliminated from the ECC. For elimination of microbubbles, a dynamic bubble trap (DBT) was developed for the arterial line of ECCs. METHODS: Bubble eliminating properties of an arterial filter were evaluated in four CABG patients and compared to the performance of the DBT in four patients. One patient received both devices. RESULTS: Elimination of bubbles between 40-120 microm was significantly higher with the DBT (88% vs. 57% with arterial filter, p=0.034). Reduction of bubbles below 40 microm was equivalent in both groups. The combination of both devices was most effective (94% for bubbles >40 microm). CONCLUSION: Arterial filter and DBT are equally effective in elimination of smaller gas bubbles. However, bigger bubbles possibly causing cerebral and peripheral organ damage are eliminated to a greater degree by the DBT.
Asunto(s)
Embolia Aérea/prevención & control , Circulación Extracorporea/efectos adversos , Puente de Arteria Coronaria/métodos , Embolia Aérea/etiología , Filtración , HumanosRESUMEN
BACKGROUND: Major risk of central or peripheral organ damage is attributed to air embolism from incompletely de-aired cardiac chambers after cardiac operations. Replacement of air by carbon dioxide insufflation into the thoracic cavity is widely used. Diffusion-weighted magnetic resonance imaging of the brain detects ischemia within minutes after onset. The reversibility of ischemia in cerebral tissue after massive gaseous emboli has not yet been described. METHODS: After selective catheterization of a common carotid artery in 15 pigs, boli of 1 mL/kg body weight of air (n = 5) or carbon dioxide (n = 5, "low dose") were applied. Five pigs received 2 mL/kg body weight of carbon dioxide ("high dose"). Diffusion-weighted magnetic resonance imaging of the brain was performed 2, 5, 10, 15, and 25 minutes after embolization. RESULTS: All animals of the "air" group showed important circulatory reactions leading to death of 2 animals. In the whole group, diffusion-weighted magnetic resonance imaging revealed irreversible hyperintense signals in both hemispheres. In the low-dose group, no change in signal intensity was observed in 2 pigs, and 3 others showed reversible changes in signal intensity, without important circulatory reactions. In 3 animals of the high-dose group, hyperintense signals were reversible, but 2 others presented with bilateral, irreversible signals in diffusion-weighted magnetic resonance imaging, accompanied by minor circulatory reactions. CONCLUSION: In contrast to the dramatic effect of air emboli, identical quantities of carbon dioxide injected into cerebral arteries of the pigs were not associated with major clinical symptoms. The early reversibility of ischemic reactions visualized in diffusion-weighted magnetic resonance imaging encourages the use of carbon dioxide insufflation as a protective method in cardiac surgery.