MASSIVE AIR EMBOLISM

Abstract

SESSION TITLE: Fellows Critical Care Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Air embolism is uncommon, but a potentially catastrophic medical emergency. Although minor cases of air embolism are asymptomatic and self-resolve, we present a case of a massive air embolism that caused the right ventricular failure and ultimately a cardiac arrest. CASE PRESENTATION: An 80-year-old female was brought to the emergency department(ED) with acute respiratory failure, after being found down at home. She was intubated in the field and mechanically ventilated. On arrival at the ED, she was hemodynamically stable. Laboratory workup was done and the patient was started on intravenous fluids and broad-spectrum antibiotics. She underwent a contrasted computed tomography (CT) of the chest and abdomen and was transferred to the intensive care unit(ICU). Soon after her arrival in the ICU, she went into a cardiac arrest. Cardiopulmonary resuscitation was performed with the successful return of spontaneous circulation. Her CT chest revealed a large air embolus in the right ventricle and pulmonary artery outflow tract, with additional scattered venous air emboli in the left brachiocephalic vein (Image 1). Intravenous fluids, inotropic support, hyperbaric oxygen were initiated and the patient was placed in the left lateral Trendelenburg position. The patient decompensated shortly and had another cardiac arrest and could not be revived. DISCUSSION: Air embolism can be arterial or venous depending on the cause. Surgery, trauma, intravascular catheters, and barotrauma such as from mechanical ventilation are common causes of air embolism. Arterial air emboli tend to cause microvascular occlusion in organs such as the brain and the heart. Smaller venous air emboli cause pulmonary microvascular occlusion and larger ones tend to obstruct pulmonary outflow tract mimicking cor pulmonale. Diagnosis is centered on high clinical suspicion and often aided by echocardiography to demonstrate intra-cardiac emboli or contrast-enhanced CT of the chest and/or pulmonary arteries to demonstrate emboli in the vasculature. In cases of large air embolism or hemodynamically unstable patients like ours, aggressive measures such as hyperbaric oxygen, mechanical ventilation, and intravenous fluids and vasopressors should be undertaken immediately. The patient should be moved to the left lateral decubitus head down position in cases of suspected venous air embolism and supine position in cases of suspected arterial air embolism. In some cases, air can be successfully aspirate from the right ventricle or pulmonary artery via a central venous catheter or pulmonary artery catheter with a limited benefit. CONCLUSIONS: This case highlights the importance of identifying an air embolism in a timely fashion as larger air emboli can be catastrophic. Prompt measures such as hyperbaric oxygen, patient positioning, and close hemodynamic monitoring should be initiated in cases of high clinical suspicion. Reference #1: Lowenstein E, Little JW 3rd, Lo HH. Prevention of cerebral embolization from flushing radial-artery cannulas. N Engl J Med 1971; 285:1414. Reference #2: Orebaugh SL. Venous air embolism: clinical and experimental considerations. Crit Care Med 1992; 20:1169. DISCLOSURES: No relevant relationships by Johnny Jaber, source=Web Response No relevant relationships by Saminder Kalra, source=Web Response No relevant relationships by Divya Patel, source=Web Response No relevant relationships by Raju Reddy, source=Web Response