2.1 Case history / examination
A 70-year-old Japanese woman with a medical history of bronchial asthma, rheumatoid arthritis, and hypertension had been prescribed a fluticasone-vilanterol combination inhaler for asthma and tacrolimus, iguratimod, and golimumab for rheumatoid arthritis. She had not experienced asthma exacerbation during the previous decade. She was a never-smoker with pollen allergy and had no history of drug allergies. Although she had a slight cough and dyspnea for a few days, she received the second dose of the mRNA-based COVID-19 vaccine BNT162b2 (Pfizer-BioNTech) and took acetaminophen to prevent fever. Approximately 12 h after vaccination, her respiratory symptoms worsened, and the patient was transported to our emergency room by ambulance. The percutaneous oxygen saturation (SpO2) was 86% (reservoir mask O2, 15 L/min). Physical examination revealed decreased respiratory sounds and a silent chest. Wheezing emerged after nebulization with the SABA procaterol. The patient had no edema, rash, or aggravation of joint symptoms.
The initial blood test showed an increased white blood cell count with eosinophilia, a negative C-reactive protein test, and increased total immunoglobulin (Ig)E. Arterial blood gas analysis before intubation revealed acute hypercapnic respiratory failure (Table 1). A 12-lead electrocardiogram demonstrated sinus rhythm with ST elevation (V2-V5, Figure 1 ), but the creatine kinase MB and troponin I levels were not elevated. Chest radiography and thoracoabdominal contrast-enhanced computed tomography revealed no acute pulmonary abnormalities. Bronchial wall thickening and a calcified nodule were detected in the lower lobe of the right lung. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid test results were negative. In the emergency department, she had a depressed level of consciousness; therefore, endotracheal intubation was performed, and intravenous corticosteroids were administered. To rule out cardiogenic disease, coronary angiography was performed, which revealed no significant coronary artery disease. However, left ventriculography and ultrasonic cardiography revealed apical akinetic expansion (apical ballooning) and severe hypokinesia of the mid-ventricular segments, with slightly reduced systolic function (ejection fraction, 47%,Figure 2,3 ).