Gaseous coronary embolism as a cause of myocardial ischemia during coronary artery bypass grafting

Massive air embolus to the left ventricle: diagnosis and monitoring by serial echocardiography

Air embolization is an unusual but potentially dangerous complication in left heart catheterization. Microbubbles can be detected with two-dimensional echocardiography, which is often used for this purpose during open heart and bypass surgeries. Permanent neurologic sequelae and hemodynamic collapse can result from embolization of air bubbles to the cerebral and coronary circulations, respectively. Hyperbaric oxygen is the treatment of choice for cerebral air embolization. We present a 39-year-old man who had air embolization during left ventriculography in the form of a large pocket of "pooled" air. The patient was treated with conservative therapy successfully. Two-dimensional transthoracic echocardiography was used to document the presence of the air and follow its dissolution.

Oxygen venous embolism after the use of hydrogen peroxide during lumbar discectomy

PURPOSE

The knee-prone position is commonly used for patients undergoing spinal surgery. Venous air embolism in such a position may be produced by the negative venous pressure gradient between the ambient air and the venous plexuses of the spinous process. When hydrogen peroxide is used to cleanse the wound, oxygen is produced. We report a case of suspected oxygen venous embolism during lumbar discectomy in the knee-prone position after use of H2O2.

CLINICAL FEATURES

Immediately after irrigation of a discectomy wound with H2O2, a dramatic decrease of the PETCO2, blood pressure and oxygen saturation coincident with ST segment elevation occurred suggesting a coronary gas embolism. Symptomatic treatment was initiated immediately and the patient recovered without any sequelae.

CONCLUSION

Although hydrogen peroxide has an innocuous reputation, cases of accidental ingestion or massive gas embolism after wound irrigation leading to death have been reported. A review of the literature suggests that many of the clinical and physiopathological features of air and oxygen emboli are similar. For both, measures of prevention and treatment of complications are similar. We argue that the use of hydrogen peroxide should be avoided during procedures where the position of the patient (sitting, knee-prone) increases the risk of gas embolism and that hydrogen peroxide is a potentially dangerous solution.

Impact of embolization during coronary artery bypass grafting on outcome and length of stay

BACKGROUND

Transcranial Doppler ultrasonography detects emboli in most patients during coronary artery bypass grafting. However, the significance of these emboli has not yet been established.

METHODS

We monitored 82 patients during coronary artery bypass grafting with this technique and related the numbers of emboli to the outcomes and length of hospital stay.

RESULTS

We detected cerebral emboli in all patients. Patients with stroke (n = 4; 4.9%) had a mean of 449 emboli, as compared with 169 emboli in patients without stroke (n = 78) (p = 0.005). Patients with major cardiac complications (n = 7) had a mean of 392 emboli, as compared with 163 in patients without such complications (n = 75) (p = 0.003). The mean hospital stay of survivors was 8.6 days in patients with fewer than 100 emboli (n = 40), 13.5 days in patients with 101 to 300 emboli (n = 23), 16.3 days in those with 301 to 500 emboli (n = 16), and 55.8 days in patients with more than 500 emboli (n = 6) (p = 0.0007). This relation was unchanged when patients with complications were excluded. The correlation between embolization and outcome was independent of the extent of aortic atheroma or age.

CONCLUSIONS

Emboli detected during coronary artery bypass grafting are significantly related to major cardiac and neurologic complications and affect length of stay in all patients, even in the absence of such specific complications.