A long-term follow-up of lung function in survivors of paraquat poisoning

1. Respiratory failure is a frequent cause of death in moderate to severe paraquat poisoning, and a transient fall in the gas transfer factor may be seen in mild poisoning. 2. The objectives of this study were to detect long-term changes in lung function in survivors of paraquat poisoning. 3. We analyzed 12 survivors retrospectively for age, sex, signs and symptoms, laboratory findings, chest X-ray findings, serum paraquat level, and lung function test. The first and the follow-up lung tests were performed at 3.7+/-1.4 weeks and 3.4+/-1.4 years, respectively. 4. Serum paraquat levels were assayed in all patients and 3/12 were above the Proudfoot's predictive line. Liver dysfunction (GOT > 50) and renal dysfunction (BUN > 30) were noted in 5/12 and 8/12, respectively. D(L)/V(A) was lower than the normal limit in the first study (3.9+/-0.6 L), but increased significantly and returned to the normal range in the follow-up study (4.5+/-0.6 L). %VC was within the normal range in either examination, but significantly decreased in the follow-up. %TLC was within the normal range in the first study (87+/-13%), but significantly decreased below the normal limit in the follow-up (81+/-13%). 5. These results indicate that survivors of paraquat poisoning may be left with a restrictive type of pulmonary dysfunction and suggest that a long-term follow-up of lung function may be necessary for survivors of paraquat poisoning.