Department of Emergency Medicine Peking Union Medical College Hospital Peking Union Medical College and Chinese Academy of Medical Sciences Beijing China;
Department of Emergency Medicine the First Affi liated Hospital of Zhengzhou University Zhengzhou China;
Accident and Emergency Medicine Academic Unit Prince of Wales Hospital the Chinese University of Hong Kong Hong Kong China;
Department of Emergency Medicine the Fourth Affi liated Hospital of Jishou University Huaihua China;
Department of Emergency Medicine the First Affi liated Hospital of Zunyi Medical University Zunyi China;
Department of Emergency Medicine Chifeng Municipal Hospital Chifeng China;
Department of Emergency Medicine Xingyi People''s Hospital Xingyi China;
Penehyclidine; Organophosphorus pesticide poisoning; Meta-analysis;