SESSION TYPE: Bronchology Cases
PRESENTED ON: Wednesday, October 24, 2012 at 11:15 AM - 12:30 PM
INTRODUCTION: Cerebral artery air embolism (CAE) is a rare event usually associated with vascular or surgical procedures, with only a few case reports noted following bronchoscopy. We report the first documented case of CAE associated with electromagnetic navigational bronchoscopy..
CASE PRESENTATION: A 61 year old male was referred for evaluation of a distal left lower lobe mass. An uneventful navigational bronchoscopy with biopsies and lavage was performed. About an hour after the procedure, he was noted to be disoriented with a right gaze preference and left sided weakness, followed by a generalized seizure and brief episode of pulselessness. A CT of the head revealed two foci in the right hemisphere consistent with CAE. He was emergently transferred to a hyperbaric oxygen chamber where he received several treatments. A brain MRI did not reveal any stenosis and transcranial dopplers were negative for microemboli. His workup included a negative echocardiogram for cardiac shunt and an EEG without epileptiform foci. He recovered fully without any neurologic sequelae from the CAE.
DISCUSSION: Air embolism occurs with gas entry into a vessel and a pressure gradient driving air into the vessel. Air may enter directly into an artery or from the venous system through a shunt. CAE occurs when air lodges in cerebral arteries disrupting distal blood flow either by direct occlusion and/or inflammatory response. It is known to occur during SCUBA diving, peripartum and medical procedures that involve cannulation of blood vessels or insufflation of air. Navigational bronchoscopy differs from traditional bronchoscopy with guide catheters that are inserted more distally than during typical bronchoscopy. Transbronchial biopsies may create a portal of entry into a pulmonary vein with air entry from the pressure gradient created during subsequent bronchoalveolar lavage, leading to CAE. Optimal management of CAE involves timely recognition and treatment with hyperbaric oxygen which increases atmospheric pressure. This compresses air bubbles and hastens nitrogen resorption while promoting restoration of distal blood flow, decreasing endothelial damage and mitigating reperfusion injury and cerebral edema.
CONCLUSIONS: Bronchoscopy is a rare cause of CAE, with only a handful of previously reported cases. Whether the distal sampling techniques associated with navigational bronchoscopy increase this occurrence remains to be seen. Suspicion for CAE must be high for any patient with a new neurologic deficit post-procedure.
1) Muth et al. Gas embolism. The New England Journal of Medicine. 2000. 342:476-482
2) Shetty P et al. Fatal cerebral air embolism as a complication of transbronchoscopic lung biopsy: A case report. Australasian Radiology. 2002;45(2):215-17.
3) Azola A et al. Fatal cerebral air embolism following uneventful flexible bronchoscopy. Respiration. 2010;80(6):569
DISCLOSURE: The following authors have nothing to disclose: Keren Fogelfeld, Richie Rana, Guy Soo Hoo
No Product/Research Disclosure InformationWest Los Angeles VA Hospital, Los Angeles, CA