Virginia Research Day 2021

Medical Resident Research Case Reports

18 Survival From Sub-Massive Pulmonary Embolus With Half Dose Systemic Thrombolysis

Stephen Canfield, DO, MS; Ryan O’Connell, DO Corresponding author: michael.moore1@LPNT.net

SOVAH Health Internal Medicine Residency Program

Context: Sub-massive pulmonary embolism (SMPE) is associated with significant right ventricular dysfunction which carries high morbidity and mortality. Compared with massive and non-massive pulmonary embolus (PE), no evidence-based medicine exists for optimal SMPE management. Case Report: A 64-year-old African American female with a past medical history of unprovoked PE 5 years ago treated with rivaroxaban for 3 years presented with 1 week of worsening shortness of breath. Medical History: PE five years ago and tubal ligation. No medications. Family History (Hx): Sister had deep vein thrombosis (DVT) after knee replacement surgery Social Hx: Sedentary office manager who is independent and performs all usual daily activities. No history of tobacco, alcohol, or illicit drug use. Pertinent Review of Systems: Recent diaphoresis, pleuritic chest pain, shortness of breath. Pertinent Physical Exam: Temp 97.6, Blood pressure 132/90, pulse 130, respiratory rate 26,

required 2L nasal cannula d/t oxygen desaturation in 80s%. No acute distress. Normal S1 and S1, no gallop. Regular rhythm tachycardia. No respiratory distress, rhonchi, wheeze, jugular vein distention, pleural rub or calf tenderness. Pertinent Lab: WBC 8,360, Hgb 14.8, Troponin 1.44, BNP 59, D-dimer 7.32, PTT 28, PT/INR 1.2/13.8. No hypercoagulation studies were done. ECG: Regular rhythm rate 128, prominent S-waves in lead I, Q-and T-waves in lead III (S1Q3T3 pattern). CT Pulmonary Angiogram had large saddle embolus in the left and right pulmonary arteries. Echocardiogram: Ejection fraction >65% with severely dilated right ventricular (RV) and severely decreased RV function. Diagnosis: Acute hypoxic respiratory failure secondary to acute high-risk, sub-massive saddle PE. Treatment: Heparin loading bolus followed by heparin drip. Heparin drip was put on hold for 10 mg tPA bolus followed by 40 mg tPA infusion over 2 hours. Repeat PTT 161 and fibrinogen levels 155, so heparin drip was resumed and continued for 36 following tPA. Patient was monitored in the ICU during and following tPA. Her symptoms and

hypoxia resolved within 48 hours of tPA. She had no signs of symptoms of severe bleeding. Bilateral lower extremity ultrasound discovered deep vein thromboses, so an inferior vena cava filter was placed. Patient was discharged home feeling well on rivaroxaban 15 mg BID for 21 days followed by 20 mg daily, indefinitely. Comment: Studies have shown that treating SMPE with anticoagulation alone had worse outcomes than with full-dose systemic thrombolysis which carries risk for severe bleeding. Currently, catheter-directed thrombolysis; low-dose systemic thrombolysis; and embolectomy are being investigated. It was fortunate that our patient responded so well to half dose thrombolytic treatment.

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