Two Successfully Treated Cases of Pulmonary Fibrosis Due to Paraquat Poisoning

ABSTRACT

Paraquat poisoning can cause severe multiple organ failure involving the kidneys, liver, lungs, adrenals, and central nervous system. The toxic effect of paraquat on the lung manifests as pulmonary edema, hypoxia, respiratory failure, and pulmonary fibrosis. However, optimal guidelines for treatment of lung fibrosis following paraquat ingestion are not available. We experienced two cases, a 45-year-old Korean male and a 66-year-old Korean male, who visited the emergency center because of paraquat poisoning. They initially received methylprednisolone pulse therapy and cyclophosphamide. Then they experienced pulmonary fibrosis approximately 10 days after admission during renal recovery. Although steroid pulse therapy with cyclophosphamide was reported to reduce mortality due to paraquat poisoning, the side effects of cyclophosphamide treatment were concerning in our patients, who had already received cyclophosphamide. Therefore, we decided to repeat steroid pulse therapy without cyclophosphamide. Fortunately, pulmonary fibrosis in these two patients resolved after repeated steroid pulse therapy. Thus, steroid pulse therapy alone could benefit patients with lung fibrosis, who have already received steroid and cyclophosphamide treatment. Herein, we report on two cases of pulmonary fibrosis due to paraquat poisoning that were treated successfully with repeated steroid pulse therapy.