INTRODUCTION:Lung injury due to oxygen toxicity following bleomycin chemotherapy is a well-recognized clinical entity. Levels of supplemental oxygen causing pulmonary injury are usually elevated but have occasionally been reported in the low to moderate range. Unilateral bleomycin oxygen toxicity has not been previously reported.
CASE PRESENTATION:A 28-year old male diagnosed with primary mediastinal germ cell tumor received 3 cycles of bleomycin (total dose = 240 units), etoposide, and cisplatin therapy. There was an excellent response with significant decrease in tumor size. Thirteen days after the final dose of bleomycin, the patient underwent a right posterolateral thoracotomy with en bloc excision of the mediastinal mass and anterior segment of the right upper lobe of the lung. The operative time was just under 5 hours. Both lungs received short-term high oxygen concentration for pre-oxygenation prior to intubation. This was followed by approximately five hours of single-lung ventilation (left side) with inspired oxygen ranging from 40 to 60 percent. On the evening of the second postoperative day, the patient developed progressive dyspnea and left-sided pulmonary infiltrates with progression to acute respiratory distress syndrome requiring reintubation. Infection and diffuse alveolar hemorrhage were ruled out. Patient was treated with high dose steroid burst followed by steroid taper. He received inhaled nitric oxide and low tidal volume strategy. The patient underwent tracheostomy placement on the tenth postoperative day. Patient had an 81-day hospital course with prolonged ventilator wean. His minimal right-sided infiltrates resolved while his left-sided infiltrative process progressed. Despite aggressive investigation no other cause for the persistent infiltrate could be documented. The patient was diagnosed with unilateral bleomycin lung toxicity. Seven months following the initial surgery, with the assistance of an intensive pulmonary rehabilitation program, the patient has returned to most of his usual activities. He has persistent severe restriction on pulmonary function tests but no longer requires oxygen. A persistent interstitial infiltrate remains on the left lung on radiologic imaging.
DISCUSSIONS:Bleomycin-induced lung injury associated with oxygen use is believed to be an oxygen free radical phenomenon leading to pulmonary fibrosis. Previously reported thoracic surgery series involving significant volume of lung resection in the setting of prior bleomycin have shown poor outcomes. Those cases differ from our case in that a small volume of lung was resected en bloc with an extensive mediastinal resection of tumor. Bleomycin lung injury manifests itself most often as a bilateral process. However, this case illustrates an unusual manifestation of bleomycin-induced oxygen toxicity due to relative sparing of the lung isolated during surgery at the time of the increased oxygen exposure.
CONCLUSION:Bleomycin can predispose the lung to severe injury secondary to oxygen toxicity. This can occur with few other risk factors as in the case presented: young age, never smoker, normal renal function and low cumulative bleomycin dose. Lung isolation, often used in thoracic surgery, can be protective as it decreases oxygen exposure to the isolated lung. Conversely, it can lead to increased oxygen being delivered to the contralateral lung, thus predisposing it to increased risk of bleomycin-related injury. Such recognition may help further guide physicians in their post-operative management of similar cases.
DISCLOSURE:Cassie Kennedy, No Financial Disclosure Information; No Product/Research Disclosure Information