Background: The main cause of death in pulmonary embolism (PE) is right-heart failure due to acute pressure overload. In this sense, extracorporeal membrane oxygenation (ECMO) might be useful in maintaining hemodynamic stability and improving organ perfusion. Some previous studies have reported ECMO as a bridge to reperfusion therapy of PE. However, little is known about the patients that benefit from ECMO. Methods: Patients who underwent ECMO due to pulmonary thromboembolism at a single university-affiliated hospital between January 2010 and December 2018 were retrospectively reviewed. Results: During the study period, nine patients received ECMO in high-risk PE. The median age of the patients was 60 years (range, 22–76 years), and six (66.7%) were male. All nine patients had cardiac arrests, of which three occurred outside the hospital. All the patients received mechanical support with veno-arterial ECMO, and the median ECMO duration was 1.1 days (range, 0.2–14.0 days). ECMO with anticoagulation alone was performed in six (66.7%), and ECMO with reperfusion therapy was done in three (33.3%). The 30-day mortality rate was 77.8%. The median time taken from the first cardiac arrest to initiation of ECMO was 31 minutes (range, 30–32 minutes) in survivors (n=2) and 65 minutes (range, 33–482 minutes) in non-survivors (n=7). Conclusion High-risk PE with cardiac arrest has a high mortality rate despite aggressive management with ECMO and reperfusion therapy. Early decision to start ECMO and its rapid initiation might help save those with cardiac arrest in high-risk PE.

Drug-induced immune hemolytic anemia is a rare disease that occurs in 1 in 1 million individuals of the general population. Rifampin-induced immune hemolytic anemia is caused by drug-dependent antibodies and this can be treated without complication by drug cessation. Herein, we present a case of rifampin-induced immune hemolytic anemia in a patient with primary Sjogren's syndrome (pSS) which occurred during treatment of pulmonary tuberculosis. At admission, the patient's laboratory tests revealed hemolytic anemia and positive direct antiglobulin test result. Since the incidence of autoimmune hemolytic anemia (AIHA) in pSS is reported to be 3 percent, which is higher than that of the general population, differential diagnosis between AIHA and rifampin-induced immune hemolytic anemia was required for planning future anti-tuberculous treatment. We identified rifampin-dependent antibody by drug-induced immune complex test and diagnosed rifampin-induced immune hemolytic anemia. Based on this experience, if rifampin administration is considered in patients with systemic autoimmune disease such as pSS, which has a high incidence of AIHA, we suggest evaluating the presence and the cause of hemolytic anemia at baseline by testing serum lactate dehydrogenase, haptoglobin, and direct and indirect antiglobulin tests before drug administration to promptly identify the cause of hemolysis if hemolytic anemia develops.