Influence of the length of time elapsed from ingestion of paraquat to hemoperfusion on prognosis in patients with acute paraquat poisoning

Objective To explore the influence of the length of time elapsed from ingestion of paraquat to hemoperfusion on prognosis in patients with acute paraquat poisoning.Methods The investigation was carried out with retrospective analysis.A total of 303 patients with acute paraquat poisoning were admitted to the Emergency Intensive Care Unit (EICU) of the First Affiliated Hospital of China Medical University from January 2009 to December 2012.According to the length of time between ingestion and hemoperfusion,patients were divided into three groups,Group A:the time interval between ingestion and hemoperfusion ＜ 4 h ; Group B:4h ≤ the time interval between ingestion and hemoperfusion ＜ 8 h; Group C:8 h≤the time interval between ingestion and hemoperfusion ＜ 12 h.Compared the extent of target organ injury,28-d mortality and the survival time of non-survivors among three groups for determining the influence of the length of time elapsed from ingestion to hemoperfusion on the prognosis of patients.Results Totally 303 patients with average age of 34.8 ± 10.8 years old (ranging from 15 to 72 years),and 117 male and 186 female.The median estimated amount of 20％ paraquat ingested was 50 mL (ranging from 10 to 270 mL,IQR:45 mL).The hemoperfusion was employed (3.6 ±1.2) times (ranging from 2 to 5 times) for every paitient within 24 h after ingestion.The overall mortality rate was 68.6％ (208/304)during a 28 days follow-up period,and only 95 of 303 patients survived.The median length of time between paraquat ingestion and hemoperfusion at the emergency department was 6.6 h (ranging from 1.4 to 11.5 h,IQR:3.5 h).However,it was 7.2 h (ranging from 3.1 to 11.5 h,IQR:2.4 h) in non-survivors and 4.9 h (ranging from 1.4 to 7.6 h,IQR:1.5 h) in survivors.The difference was statistically significant (U =2.014,P =0.043).The difference in 28-day mortality among three groups was statistically significant (x2 =9.27,P =0.009),and the difference in average survival time of non-survivors among three groups was statistically significant (F =3.31,P =0.038).The length of time between ingestion and hemoperfusion and the survival time of non-survivors was a negative correlation (r2 =0.421,P =0.045).The difference in ALTmax,SCrmax,AMYmax and PaO2 min,as the severity indicators of acute liver injury,acute kidney injury,acute pancreas injury and acute lung injury among the three groups were statistically significant (all P ＜ 0.05).Conclusions Employment of hemoperfusion within 4 h after ingestion can attenuate the degree of target organ injury,reducing 28 day mortality of patients with acute paraquat poisoning. Key words: Hemoperfusion;  Paraquat;  Poisoning;  Prognosis