Airways and Airheads: A Case of Bronchoscopy-Induced Cerebral Arterial Gas Embolism.

SESSION TITLE: Bronchology/Interventional Student/Resident Case Report Posters IISESSION TYPE: Medical Student/Resident Case ReportPRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PMINTRODUCTION: Cerebral arterial gas embolism (CAGE) is a rare but potentially catastrophic result of introducing air into the systemic arterial circulation. It is usually associated with vascular procedures. We describe a case associated with endobronchial biopsies of invasive mycosis under positive pressure ventilation.CASE PRESENTATION: A 63-year-old man with idiopathic pulmonary fibrosis status post left single lung transplant and prior pulmonary embolism underwent outpatient bronchoscopy for anastomotic site stenosis. Outpatient medications included tacrolimus, mycophenolate, prednisone and warfarin, which was held for the procedure. Flexible bronchoscopy revealed circumferential anastomotic site stenosis and a lingular endobronchial mass with complete luminal obstruction. Rapid bleeding of approximately 150cc developed after biopsy of the mass. Topical epinephrine was administered and the bleeding stopped. The patient was ventilated through an endotracheal tube for the procedure. Pathology revealed fungal hyphae invasion of bronchial wall tissue with associated necrosis. Fungal identification remains pending with suspected Dematiaceous species. During recovery the patient became altered, dysarthric and ataxic with an episode of transient visual floaters. MRI revealed infarcts in the right cerebellar tonsil, inferior hemisphere, right occipital lobe and bilateral corona radiata. A dilated retinal exam was consistent with left retinal emboli. A search for a thrombotic source including brain and neck MRA, trans-thoracic echocardiogram with bubble, trans-cranial dopplers, chest CT angiogram and lower extremity dopplers were negative. A lumbar puncture was negative. A hypercoagulable work up was also unrevealing. The patient did well and was discharged with minimal deficits.DISCUSSION: CAGE is a rare complication associated with vascular procedures, pulmonary barotrauma and diving accidents. Presentation is similar to cerebral vascular accidents. Entry into the cerebral vasculature requires either direct introduction of air to the systemic arterial system or paradoxical embolization. CAGE secondary to bronchoscopic procedures has been reported with transbronchial biopsies, air cooled laser and argon plasma coagulation. In our patient, we hypothesize endobronchial hemorrhage from invasive mycosis during positive pressure ventilation lead to the introduction of air into the pulmonary veins.CONCLUSIONS: CAGE is a rare complication of bronchoscopic procedures. We report the first case of CAGE attributed to pulmonary invasive mycosis and endobronchial hemorrhage in the setting of positive pressure ventilation.Reference #1: Azzola A, von Garnier C, Chhajed PN, Schirp U, Tamm M. Fatal cerebral air embolism following uneventful flexible bronchoscopy. Respiration. 2010;80(6):569.Reference #2: Reddy C, Majid A, Michaud G et al. Gas embolism following bronchoscopic argon plasma coagulation: a case series. Chest. 2008;134(5):1066.DISCLOSURE: The following authors have nothing to disclose: Huawei Dong, Brandon Grimes, Scott Oh, Irawan SusantoNo Product/Research Disclosure Information.