Bronchiolitis Obliterans With Recurrent Pneumothorax After Allogeneic Bone Marrow Transplantation

Bronchiolitis obliterans syndrome (BOS) is a non-infectious pulmonary complication that can occur in patients who have undergone allogeneic bone marrow transplantation (BMT). BOS is characterized by the irreversible narrowing and obstruction of bronchi, resulting in severe respiratory distress and poor outcomes. This case report focuses on the complex management of a patient with a multifaceted medical history. A 20-year-old man was initially diagnosed with precursor B lymphoblastic lymphoma and subsequently underwent allogeneic BMT. Nine months later, the patient was diagnosed with bronchiolitis obliterans with graft-versus-host disease, resulting in the development of BOS. Remarkably, 12 years after BMT, the patient was registered for lung transplantation. However, one year after registration, the patient developed a left pneumothorax. Despite rigorous efforts, including continuous thoracic drainage and autologous pleurodesis, the pneumothorax did not respond to treatment and required video-assisted thoracic surgery (VATS) bullectomy. The preoperative assessment revealed a challenging clinical finding characterized by the need for home oxygen therapy (5 L/min with a nasal cannula), severe Hugh-Jones classification IV-V, and marked hypercapnia (partial pressure of carbon dioxide (pCO₂), 76 mmHg). Imaging studies, including high-resolution computed tomography and chest radiography, revealed hyperinflation, emphysematous changes, and bronchiectasis across all lung lobes, further complicating the patient's condition. Intraoperative management had the unique challenges of persistent hypoxia (P/F ratio 65-80), positive end-expiratory pressure of 5 cmH₂O, and low tidal volumes (1.6-2.0 mL/kg) during one-lung ventilation. To address these problems, both-lung ventilation had to be performed intermittently. However, hyperventilation remained unmanageable, with maximum pCO2 values reaching 140 mmHg. Following surgery, the patient had to be admitted to the intensive care unit in an intubated state. Fortunately, the following day, the patient's condition improved markedly, his state of consciousness was clear (Glasgow Coma Scale 15) and his pCO₂ level improved (66 mmHg) with spontaneous breath. This course of events allowed extubation and the patient was discharged to the general ward only two days after surgery. This case highlights the critical importance of a comprehensive preoperative assessment, including advanced imaging, when managing patients with BOS and complex pulmonary complications. Furthermore, it highlights the complexity and difficulty of perioperative respiratory management in such cases.