Alveolar–arterial partial pressure difference as an early predictor for patients with acute paraquat poisoning

OBJECTIVE: Paraquat (PQ) is associated with high mortality rates in acute poisoning. This study aimed to determine the importance of the alveolar–arterial partial pressure difference (A-aDo(2)) in the expected consequences of acute PQ poisoning. METHODS: Patients who were hospitalized for PQ poisoning in 2018 were enrolled in this retrospective study. A-aDo(2) data were collected. Multivariate analysis was performed using binary logistic regression to determine whether A-aDo(2) is an independent risk factor for mortality from PQ. RESULTS: A total of 352 cases were analyzed. The mean PQ dose was 36.84 ± 50.30 mL (0.3–500 mL). There were 185 survivors and 167 non-survivors. The mean A-aDo(2) was not significantly correlated between survivors and non-survivors on day 1. However, there were significant differences in A-aDo(2) between survivors and non-survivors on days 3, 7, 14, and 21. Increased A-aDo(2) values were correlated with an increased mortality rate. The mean A-aDo(2) on day 14 showed the most significant difference between survivors and non-survivors. CONCLUSION: Our study suggests that A-aDo(2) plays an important role as a reference index, which could be a useful predictor in assessing acute PQ poisoning, especially on the 14th day after onset of poisoning.