A new method for predicting the outcome and survival period in paraquat poisoning.

1. To elucidate the importance of lung damage in the prognosis of paraquat poisoning, the respiratory index (RI: A-aDO2/PO2) was analysed in 51 patients with paraquat poisoning. 2. Progressive deterioration of the RI was observed in 43 non-survivors, but not in 8 survivors. In addition, the RI of non-survivors became greater than 1.5 in the course of their poisoning, while that of the survivors remained less than 1.5. 3. The level of the RI (i.e. whether it became greater than 1.5 or not) was found to be a good indicator for the prognosis for life. 4. The RI-time, defined as the time taken from ingestion for the RI to be greater than 1.5, was found to be a good indicator for predicting the survival period in fatal cases. 5. As a result, we conclude that it is important and useful to examine a series of RI and the RI-time in poisoned patients not only to provide proper respiratory care, but also to predict outcome and survival period.