PURPOSE: Air embolism (AE) is a complication during transthoracic needle biopsy (TNB). We report the case of venous and systemic AE during CT-guided TNB.
METHODS: A 27-year-old patient with a neoplasm of his testis underwent TNB of a right upper lobe pulmonary lesion. In supine position, the procedure was carried out under general anesthesia with positive pressure ventilation (PPV). During the intervention the radiologist observed accumulation of air bubbles in the left cardiac ventricle and atrium, in the right subclavian vein, the superior vena cava and the right atrium. A patent ovale foramen was diagnosed. The patient was kept head-down, FiO2 was set to 1.0 and treatment with heparin was started. Anaesthesia was maintained, the patient was not moved until the air bubbles were completely resorbed as proved by CT-scan. Neurological examination after weaning from ventilation was unremarkable.
CONCLUSION: There are numerous ways of AE occurring during CT-guided TNB. First, air can enter the pulmonary circulation when the needle tip is inserted into the pulmonary vein and the stylet is removed in spontaneous breathing patients. Second, air can enter through a bronchovenous fistula created by the needle passing through the lung parenchyma during elevated intralveolar pressure under PPV(1).Third, venous AE due to pressure infusion of contrast media (CM) for CT is frequently reported (2) and seemed to be the most likely cause in our patient. Venturi forces could have permitted air to enter via a stop-cock improperly fixed to the venous cannula. Pump failure including filter leakage is another possibility.
CLINICAL IMPLICATIONS: Prevention of AE due to administration of air during CM-infusion is a subject for institutional risk management. Stop-cocks and injection valves should not be used in intravenous lines supplied by pressure infusion devices. Adverse outcome may be avoided by placing the patient in a head-down position, increasing FiO2 to 1.0, commencing antithrombotic therapy, immobilizing and keeping the patient on the CT intervention table until AE is proved to have subsided.
DISCLOSURE: Franz Wiedermann, No Financial Disclosure Information; No Product/Research Disclosure Information