Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 0 0 2026 02 27 1551 1551 Erick Tanara Departement of Anesthesiology and Reanimation, Faculty of Medicine, Universitas Airlangga, Surabaya, Indonesia. & Dr.Soetomo General Academic Hospital, Rumah Sakit Dokter Soetomo, Surabaya, Indonesia. Fajar Perdhana Departement of Anesthesiology and Reanimation, Faculty of Medicine, Universitas Airlangga, Surabaya, Indonesia. & Dr.Soetomo General Academic Hospital, Rumah Sakit Dokter Soetomo, Surabaya, Indonesia. 2025 12 31 2026 01 07 Myasthenia gravis (MG) is an autoimmune disorder affecting the neuromuscular junction. This condition is often associated with respiratory and bulbar muscles and increases the risk of aspiration and respiratory failure. Studies have shown that respiratory issues, such as pneumonia, may lead to higher morbidity and mortality. A 54-year-old woman was admitted to an intensive care unit (ICU) due to myasthenic crisis triggered by pneumonia. Her condition was complicated by progressive dyspnea, dysphagia, recurrent choking, and cough. After admission, she exhibited respiratory issues (a PF ratio = 265) while receiving high-flow nasal cannula (HFNC) support, and elevated procalcitonin levels. Because the ROX index keeps declining, she decided to undergo elective intubation and received mechanical ventilation. The treatment was initially administered using pressure-controlled settings, followed by an adaptive support mode. Sputum culture identified Acinetobacter baumannii and Streptococcus pneumoniae, which were sensitive to cefoperazone–sulbactam. After 14 days of the regimen, there was a gradual clinical improvement and a decrease in procalcitonin levels. The patient also received pyridostigmine dosing, intravenous methylprednisolone, plasma exchange, and enteral nutrition. Due to prolonged ventilator dependence, a percutaneous dilatational tracheostomy was performed, facilitating successful weaning and transfer to a lower-care unit. This case highlights the importance of early recognition of HFNC failure, timely transition to invasive ventilation, and integrated multidisciplinary management (immunologic, antimicrobial, ventilatory, and nutritional strategies) in patients with myasthenic crisis complicated by pneumonia. https://aacc.tums.ac.ir/index.php/aacc/article/view/1551