INTRODUCTION: Argon plasma coagulation (APC) is a non-contact mode of electrical coagulation that uses electricity generated heat to destroy tissue with immediate effect (1). It is commonly used during therapeutic bronchoscopic for debulking of endobronchial lesions, coagulation of visible endobronchial hemorrhage and treatment of stent induced granulation tissue. APC is considered to be relatively safe when used by experienced personnel. However, there have been cases of systemic, life-threatening gas embolism reported as a complication of its use (2). We report a case of life-threatening gas embolism associated with APC with successful recovery.
CASE PRESENTATION: A 66-year-old woman with a history of resected colon cancer with lung metastasis, s/p left lower lobe lobectomy complicated by endobronchial involvement with hemoptysis and central airway obstruction requiring rigid bronchoscopy, mechanical debridement and APC 6 months ago. The patient returns with an obstructing left main stem lesion and hemoptysis. She was admitted to the hospital and underwent successful left bronchial artery branch embolization. She was then taken to the operating room for a rigid bronchoscopy with mechanical tumor debridement and argon plasma coagulation which was complicated by gas emboli. A transesophageal echocardiogram (TEE) prior to the procedure was normal. A TEE during APC showed significant amount of gas emboli in the left atrium and left ventricle immediately after APC was commenced. The procedure was terminated immediately. The patient was placed in the Trendeleburg position. Within 15 seconds the electrocardiographic rhythm showed ST depression and T wave inversions. This was followed by hypotension and shock. The rigid bronchoscope was removed and the patient was intubated with endotracheal tube. The LV was globally depressed transiently and improved with resuscitation using epinephrine and phenylephrine. Subsequently with positive pressure ventilation, large amounts of gas emboli were seen during positive pressure breaths and decreased during apnea. A repeat flexible bronchoscopy was performed with no evidence of bleeding. At the end of the case, patient was extubated and transferred to the ICU for monitoring. The patient had complete recovery with no evidence of CNS/ systemic emboli. A transthoracic echo prior to discharge did not show evidence of residual ventricular dysfunction.
DISCUSSIONS: The exact etiology of gas embolism with APC remains unclear. However, in our case, a bronchial-vascular fistula created by the coagulation of the tumor is the most likely explanation. Our case highlights a significant lag time between the appearance of gas emboli detected by the TEE and the ECG changes. This may delay implementation of appropriate therapy and may impact the patient’s outcome.
CONCLUSION: APC is an important tool available to the interventional pulmonologist. Although gas embolism is infrequent, it is life threatening and raises the question for the need of intra operative monitoring with a TEE for all these cases where APC is being used.
DISCLOSURE: Samaan Rafeq, No Financial Disclosure Information; No Product/Research Disclosure Information