MASSIVE AIR PULMONARY EMBOLISM: IS IT REAL?

Abstract

SESSION TITLE: Fellows Pulmonary Vascular Disease Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Air embolism is a rare but potentially catastrophic condition that occurs when air enters into the vasculature. Here we present a case of venous- air-embolism causing hemodynamic compromise that was treated with hyperbaric oxygen. CASE PRESENTATION: 63 years old female with COPD on LTOT presented at an outside hospital with worsening shortness of breath, found to be in hypercarbic respiratory failure presumable from acute exacerbation of COPD. Peripheral iv lines were placed, she was given fluids and placed on antibiotics, nebulizers and steroids. Patient rapidly deteriorated into refractory shock requiring pressors and hypoxia needing endotracheal intubation. Patient was also noted to have a seizure while in the ED. On transfer to our hospital, patient continued to remain in refractory shock and refractory hypoxia with PaO2/FiO2 ratio of 150. CXR showed changes consistent with obstructive lung disease. CT scan of chest was performed given unexplained hypoxia and shock which showed evidence of air in the main pulmonary artery extending into the segmental and subsegmental arteries with air also tracking from left subclavian vein into SVC. CT scan of head was unremarkable. Diagnosis of venous air embolism was made, and patient was placed in left lateral decubitus, Trendelenburg position with 100% FiO2 on the ventilator. Decision was made to proceed with hyperbaric oxygen therapy (HBO) due to severe hemodynamic instability. ENT was consulted for bilateral myringotomies prior to the therapy. Patient successfully received hyperbaric oxygen therapy for almost 7 hours, with complete resolution of air embolism on repeat CT scan of chest. Patient came off of vasopressors immediately after completion of treatment. She was extubated on day 4 of mechanical ventilation. DISCUSSION: Air embolism is a rare but potentially catastrophic condition that occurs when the air enters into the vasculature. It can be venous and arterial. Common causes include vascular intervention, surgery, trauma, barotrauma from mechanical ventilation and diving. Diagnosis require high clinical suspicion and imaging evidence. Treatment options are limited including positioning, HBO and direct removal of air. Venous embolisms are self-limiting if volume of air is <50 ml, beyond which patients can have direct and indirect effect of embolism. Based on indications different treatment tables are used for HBO therapy. It was thought that our patient had iatrogenic air embolism from IV access placed on the left arm. She was appropriately started on HBO as she was hemodynamically unstable. There is limited literature about direct removal of air using catheters and it is typically performed when catheters are already in place. CONCLUSIONS: Air embolism, especially pulmonary air embolism, is life threatening and prompt intervention with appropriate positioning and HBO are life saving measures. Reference #1: King, Melissa B., and Keith R. Harmon. “Unusual forms of pulmonary embolism.” Clinics in chest medicine 15.3 (1994): 561-580. Reference #2: Leach, R. M., P. J. Rees, and P. Wilmshurst. “Hyperbaric oxygen therapy.” Bmj 317.7166 (1998): 1140-1143. Reference #3: Bessereau, Jacques, et al. “Long-term outcome of iatrogenic gas embolism.” Intensive care medicine 36.7 (2010): 1180-1187. DISCLOSURES: No relevant relationships by Hassan Yousaf, source=Web Response