ABSTRACT
Objective In order to extrapolate the respiratory dysfunction of patients in early stage of acute organophosphorus pesticide poisoning (AOPP),transpulmonary thermodilution technique was used in swine models of severe acute dichlorvos poisoning (SADP) to evaluate respiratory function.Methods Twenty healthy female swine were randomly divided into dichlorvos ( n =7 ),atropine ( n =7 ) and control (n =6) groups.In the dichlorvos group,the swine were administered with 80％ emulsified dichlorvos (100mg/kg) via the gastric tube toinduce SADP.In the atropine group,swinewere administered with dichlorvos,and 0.5h later,atropine was injected to obtain and maintain atropinization.The swine of control group were administered with saline solution instead.Arterial and venous blood samples were collected 0,0.5,1,2,4 and 6 hours after modeling for blood gas analysis and detecting acetylcholinesterase levels.Both extravascular lung water index (EVLWI) and pulmonary vascular permeability index ( PVPI ) were measured by using PiCCO (pulse indicator continuous cardiac output ). At the termination of the experiment,the animals were sacrificed and the lung wet/dry weight ratio was determined and histopathological changes of lung tissue were also observed under microscope.Results In the dichlorvos group,EVLWI and PVPI were substantially increased from 0.5 h to 6 h after modeling but PaO2/FiO2 decreased from 0-6 h after modeling.In the atropine group,EVLWI and PVPI increased initially,but then they decreased 1 h afterwards and PaO2/FiO2 was also gradually decreased from 0-1 h.In both dichlorvos group and atropine group,the EVLWI was negatively correlated with PO2/FiO2 and positively correlated with PVPI.Compared with the control group,the lung wet/dry weight ratio increased markedly in the dichlorvos group and mildly increased in the atropine group.Meanwhile,the histopathological changes of lung tissue were obvious in the dichlorvos group and mild in the atropine group.Conclusions SADP swine experienced substantial changes in respiratory function. EVLWI was a reliable and valuable indicator for evaluating respiratory function in the early stage of AOPP.