The Value Of Arterial Blood Gas Analysis In The Evaluation Of Acute Paraquat Poisoning Patients

Paraquat poisoning has become a common disease of the emergencydepartment in China. The poisoning dose of paraquat is very small, andthe mechanism of paraquat poisoning is not yet fully clear. due to the lackof effective and specific treatment，paraquat poisoning can cause highmortality, and has brought great challenges to emergency doctors.Therefore, finding practical prognostic factors which related to paraquatpoisoning can guid clinical treatments, especially to explore some earlylaboratory indicators that are easy to get in clinic，which will make itmore sense.Objective A study was made by observation of acute paraquatpoisoning patients clinical data, blood gas analysis and other indicators atthe time they admitted to our hospital，our aim was to find the value ofarterial blood gas analysis in the evaluation of acute paraquat poisoningpatients.Methods Acute paraquat poisoning patients who admitted into ourhospital emergency department and ICU hospitalization from January,2011to October,2012were collected. A total of68cases became the finalselected after exclusion some patients who did not meet our conditions. Basic routines，laboratory tests and blood gas analysis of the patientswere recorded at the time they admitted into our hospital. If patients diedin hospital, we will record the time of their deaths, We would call all ourpatients by phone who had leaved hospital and followed up for twomonths. Our patients were divided into survival group and death groupaccording to whether they died in two months or not, and according totheir time of survival, the death group will further be divided. Accordingto the BE value of the blood gas analysis, We will again group all of thepatients into three groups: BE＞-2.0mmol/L；-5.0mmol/L≤BE≤-2.0mmol/L and BE<-5.0mmol/L, The routine general clinical datas,laboratory examinations, blood gas analysis and case fatality rates wouldbe compared and analysed among the three groups according to ourgrouping. SPSS17.0statistical software were adopt to process andanalysis these data indicators, ROC curve were also used to judge theindicators distinguish ability in prognosis of patients with paraquatpoisoning.Results （1）There are no statistical significances between survivalgroup and death group in age, gender, admission time, gastric lavage timeand PH, PO₂（P>0.05），But in the amount of poison, blood CR, BE value,HCO₃-, PCO₂, lactic acid, there have significant differences between thetwo groups （P <0.01）；（2）There are no statistical differences in age, sex,time of gastric lavage time, admission time, blood PH, PO₂among early death group（d≤3d），medium-term death group （3d＜d＜7d） and the latedeath group（d≥7d）（P>0.05），In terms of the amount of poison therewas statistically significant （P <0.01），In BE value, HCO₃-, PCO₂andlactic acid value there has significant difference （P<0.01）；（3）There areno statistical differences in age, sex, time of gastric lavage, admissiontime among the group of BE＞-2.0mmol/L，-5.0mmol/L≤BE≤-2.0mmol/L and BE<-5.0mmol/L, But in the amount of poison, the numberof deaths and case fatality rates there exist obvious differences （P <0.01），the smaller BE values of the group, the more quantity paraquatpatients commit, and the higher case fatality rate was, when BE <5mmol/L, the case fatality rate reaches100percent.（4） The value of BE,PCO₂, HCO₃-, lactic acid for judging the prognosis of the area under thecurve by the ROC curve analysis are:0.930（95%[CI]，0.869-0.991）,0.893（95%[CI],0.827-0.960）,0.924（95%[CI],0.873-0.924）,0.958（95%[CI],0.925-0.992） respectively, Optimal cut off value are-2.9mmol/L,32.5mmHg,22.2mmol/L,3.6mmol/L respectively.Conclusions （1） BE values, HCO₃-, PCO₂, lactic acid of the bloodgas analysis, which were collected at early time of poisoning can be anearly indicator for judging the prognosis of patients with paraquatpoisoning, the death patients has a decrease in BE values, HCO₃-, PCO₂，and increase in lactic acid.（2） BE values, HCO₃-, PCO₂and lactic acid ofthe early time blood gas analysis are associated with death in patients with paraquat poisoning, the shorter the time of survival, the smaller ofthe BE values, HCO₃-、PCO₂, and the larger of lactic acid values.（3） Asthe BE value, which is collected on admission, becomes smaller, the casefatality rate of the patients increase.（4） As indicators that can judge theprognosis of patients with paraquat poisoning, BE value, HCO₃-, PCO₂,lactic acid value have high values in sensitivity, but low in specific degree,It can be used as a sensitive but not specific indicators of prognosis forparaquat poisoning.