(1143) Pulmonary Reperfusion Injury After Thrombectomy for Pulmonary Embolism

Introduction: Pulmonary embolism (PE) ranks as the third most common cause of cardiovascular death, though its estimated mortality is likely underrepresented as its presentation is highly variable. Depending on risk stratification, treatment ranges from oral anticoagulation to thrombectomy. This case details pulmonary reperfusion injury (PRI), a rare complication of thrombectomy, in a man who initially presented with an intermediate risk PE.

Description: A 50-year-old active-duty man presented to the emergency department with worsening exertional dyspnea and left-sided chest pain. Upon initial intake he was found to have an oxygen saturation (SpO2) of 74% on room air but was hemodynamically stable. SpO2 improved to 90+% on 30L heated high flow nasal cannula (HHFNC) and CT PE protocol demonstrated extensive bilateral PEs with evidence of right heart strain and left upper lobe infarct. Chemical biomarkers were within normal limits. The patient was started on a heparin drip and admitted to the ICU for acute hypoxic respiratory failure in the setting of intermediate risk PE.

The patient underwent successful catheter-directed pulmonary artery thrombectomy and had improved SpO2. The next day his chest pain returned and his partial pressure of oxygen (PaO2) ranged from 56-67mmHg despite HHFNC, requiring intubation. Bronchoscopy demonstrated copious serosanguineous fluid in the left lung concerning for necrotic tissue and PRI.

The patient was oxygenated on a low-tidal volume protocol and eventually liberated from the ventilator. Repeat CT chest demonstrated improved aeration of the left upper lobe. Over time his oxygen requirements decreased, and he was discharged with supplemental oxygen and three months of anticoagulation.

Discussion: PRI is a rare but potentially catastrophic complication of PEs managed with thrombectomy or thrombolysis. It is caused by a sudden increase of pulmonary blood flow with elevated pulmonary vascular resistance that disrupts the alveolar-capillary unit and causes increased vascular permeability. There is no specific treatment for PRI. Management is based on supportive care of the respiratory distress while minimizing further lung damage. Given the increasing use of catheter-directed interventions in PE treatment, PRI is a complication that may be seen more frequently.