Gas Embolism: Part I. Venous Gas Emboli

Abstract

Gas emboli syndromes occur in many different settings, and their medical significance ranges from being life-threatening emergencies to being totally innocuous. We discuss venous gas embolization in Part I of this review, and it can result from a variety of traumatic, diagnostic, therapeutic, and surgical interventions. The pathophysiological consequences depend on where the gas bubbles impact and obstruct the circulation—by creating an “air lock” in the right ventricle, by obstruction of pulmonary arterioles, and sometimes with passage into the arterial circulation (so called paradoxical emboli). Various monitoring techniques are available and are known to be useful in high-risk patients. Nevertheless, the diagnosis can be difficult to establish. Myriad and generally nonspecific clinical manifestations may be present; the patient may often exhibit signs and symptoms suggestive of other acute cardiopulmonary or central nervous system events. The classically described “mill-wheel murmur” is actually a rare finding, and it is transient at best. There are no specific diagnostic tests available, and clinicians, must depend on a high level of suspicion in the appropriate settings. Rapid identification of the problem, with prevention of further gas entry into the venous circulation, should be a routine measure. The left lateral decubitus position, administration of 100% oxygen, and hyperbaric oxygenation should all be considered, and they have been shown to be effective treatment modalities.