The Value Of Initial Clinical Datas Of Patients With Paraquat Poisoning For Prognosis And The Intervention Effection Of Blood Purification Therapy

[Background and objective]Paraquat (PQ), an organic heterocyclic herbicide,is widely used, which has high toxicity to humans and animals. Paraquat can be absorbed through the gastrointestinal, respiratory and skin mucous membrane, oral poisoning as the principal way of poisoning. The mortality rates of oral paraquat poisoning reported in the literature is inconsistent, mostly in more than 50%. Early,patients with paraquat poisoning can only show oropharyngeal and localized corrosion damage of the esophagus, even asymptomatic, and then some patients progress rapidly, even die a few hours or days, only a small number of patients can survive after acute period.There is no specific antidote for paraquat poisoning, and there is no effective therapy. Paraquat is general distribution through the circulation, causing multiple organ system dysfunction, even death.Due to a poor prognosis, paraquat poisoning has attracted worldwide attention now.Detection of blood concentration of paraquat in paraquat poisoning patients is a valuable to treatment of the disease and the prognosis. But there is no satisfactory method of rapid detection of paraquat in plasma. Existing detection methods are more cumbersome, time-consuming and not conducive to clinical practice. Therefore establish a specific, sensitive and rapid detection method of plasma paraquat concentration. And the method would contribute to estimate poisoning severity, establish prognostic indicators, and evaluate clinical treatment effect. Accurate judgement of the prognosis of paraquat poisoning patients can avoid excessive medical treatment for those who are hopeless or mild poisoning patients with inappropriate, save medical resources, and reduce the financial burden on patients.Damage of paraquat occurs mainly in lungs, which may be through redox reactions and continue to produce oxygen free radicals. Several early response gene expression can be induced by oxidant and activating transcription factors, leading to inflammatory response. Experiments in vitro and in vivo showed that, in addition to lung damage, paraquat also cause liver, kidney, heart, pancreas, brain and other organ damage. Currently there is no uniform standard for prognosis of paraquat, resulting in making therapy has some blindness. There is no accurate grasp of timing and dose in the using of blood purification, glucocorticoids, and immunosuppressants. There may be excessive medical treatment for patients with mild, but had no effective role for critically patients. This study attempts to investigate the main factors affecting the prognosis of patients with paraquat poisoning by poisonous dosage and initial laboratory data.Mechanism of paraquat poisoning injury is not clear now. Some study suggest that the imbalance of cytokine network is an important cause of paraquat intoxication induced pulmonary injury. So clearing the blood of paraquat and expression of cytokines as soon as possible is the key method to successful treatment, and exploring new nethord for removing poison is the key point of clinical poisoning treatment. Early blood perfusion can remove paraquat absorbed into the bloodstream. And it is widely used in the treatment of patients with paraquat poisoning, but curative effect has not to achieve satisfactory result. Hemofiltration is often used in severe acute pancreatitis, sepsis, circulatory instability of renal failure, multiple organ dysfunction syndromes, and other critical patients. It can remove inflammatory factor, adjust immune system, improve tissue oxygenation, reduce volum overload, and so on. In this study, we detected the changes in plasma drug concentration of acute paraquat poisoning patients before and after the blood perfusion and the changes in serum cytokine concentrations before and after CVVH. The intervention effect of HP+ CVVH therapy in acute paraquat poisoning and its influence on prognosis was evaluated.[Methods]1. Research objects and groups2014.06-2015.05, the patients with oral paraquat poisoning in emergency department of Binzhou Medical University Hospital were selected, commit time less than 24 hours, aged 18 to 70 years old.This study uses two grouping scheme.Programme I:With the death or follow-up 2 months as an end point, the patients were divided into survive group and death group. The paraquat dosis, plasma concentration of paraquat, plasma urea nitrogen (BUN), creatinine (CREA), alanine aminotransferase (ALT), aspertate aminotransferase (AST), direct bilirubin (DBIL) and indirect bilirubin (IBIL), amylase (AMY), creatine kinase isoenzyme (CK-MB), peripheral blood leukocyte count (WBC), neutrophil percentage (N%) at admission in patients were recorded. Generally condition of the patients, paraquat dosis, plasma concentration of paraquat, hepatic function, renal function, amylase, myocardial enzymes, and white blood cell index between the two groups were compared. Logistic regression analysis was carried out to analyse the effects of various parameters on survival rate.Programme Ⅱ:According to whether accept blood purification therapy, patients were divided into control group and blood purification group:two groups accept general medical treatment, blood purification group also accept blood perfusion combined hemofiltration treatment. Patients began HP treatment within 1 hours after admission. HP continued for about 2 hours, and followed by CVVH therapy immediatly, last 48 hours. The plasma concentration of paraquat, transforming growth factor beta (TGF-β), tumor necrosis factor alpha (TNF-a), interleukin 1 (IL-1)of control group were detected when the patient was admitted to hospital,3 hours after admission,51 hours after admission. The same indicators of blood purification group were detected on patients soon after admission, HP therapy (3h) and CVVH therapy (51h). Plasma concentration of paraquat of two groups were compared after general treatment(3h) or HP therapy. Plasma concentration of IL-1-、TNF-α and TGF-β of two groups were compared after general treatment(51h) or HP+CVVH therapy. Plasma concentration of paraquat of blood purification group were compared before and after HP therapy. Plasma concentration of IL-1-、TNF-a and TGF-β of blood purification group were compared before and after CVVH therapy. The overall survival time and mortality of patients were compared. The mortality and survival time of the deaths of two groups were compared.2. Method establishment for determination of plasma concentration of paraquat in paraquat poisoning patientsThe plasma samples were deproteimized with 35% perchlorld acid. The mobile phase consisted of O.lmol·L-1 phosphate buffer(75mmol·L-1 sodium heptanesulfonate)-acetonitrile(88:12),adjusted pH to 3.0 by triethylamine, at a flowrate of 1.0mL·min-1, and the detection occurred at 258 nm, column temperature at 28℃. Specificity test under the condition of the chromatographic methods was carried out, a standard curve was establish, absolute recovery, relative recovery, precision in intra-day and inter-day was detected, and freeze-thaw stability experiment were carried out.3. Morphological analysis of lung and liver of death patientsThe lung, liver specimens from some patients of death was extract and analysed by routine HE staining.4. Detection of plasma cytokinesPlasma level of IL-1、TNF-β and TGF-β were detected by biotin double antibody sandwich enzyme-linked immunosorbent technique.[Results]1. Method for the determination of paraquat in plasma in patients with paraquat poisoningUnder the chromatographic conditions in this study, the shape of paraquat in plasma was well and completely, without impurities peak interference within the plasma. Retention time of paraquat is about 6-9min. This method has perfect specificity. The standard curve regression of plasma concentration of paraquat equation for y=0.000011x-0.9956, r=0.998, y for paraquat concentration (μg·mL-1), x as the peak area. A good linearity was obtained in the concentration range of 0.2～500μg·mL-1. The minimum detection limit (S/N=3) up to 0.1μg·mL-1. The average absolute recovery was 100.6%, RSD less than 3%; The average relative recovery was 101.31%, RSD less than 6%. The RSDs of precision in intra-day and inter-day were less than 6%. Under the experimental conditions, after repeated freeze-thaw cycles and freezing, concentration of paraquat showed no significant difference.2. The prediction value of initial clinical data to the prognosis of patients with paraquat poisoning.Statistical analysis showed that:the dose of survival group was less than that of death group obviously (32.50±14.07ml VS118.27±141.90ml). Plasma concentration of paraquat of survival group was lower than that of death group significantly (7.26± 4.52mg/L VS 17.72±7.53mg/L). ALT、AST、DBIL levels of survival group were lower than those of death group significantly, and IBIL level group have no obvious difference compared with death group. BUN、CREA and AMY、CK-MB level of survival group were lower than those of death group significantly. Leukocyte level of survival group was lower than that of death group, and neutrophil percentage has no obvious difference compared with death group.The white blood cell levels and neutrophil percentage of survival group were(9.13±1.71) X 109/L and (82.59± 7.47)% respectively, while which of death group were (21.98±9.00) X 109/L and (85.55±10.47)% respectively. Logistic regression analysis found that plasma concentration of paraquat have obvious influence on survival..3. Morphologic characteristics of paraquat induced lung injuryMorphological change of lung injury have the following characteristics:destroyed, alveolar epithelial injury, alveolar septal fracture, fusion, part of alveolar septal widened, little exudate in alveolar cavities, red blood cells can be found in part of the alveolar cavities.4. The changes in plasma concentration of paraquat and inflammatory markers after blood purification therapy. The correlation of blood purification therapy and prognosis.On admission, the plasma concentration of paraquat and cytokine (TNF-α、 TGF-β、IL-1) had no obvious difference between blood purification group and the control group.3h after admission, the plasma concentration of paraquat of blood purification group was reduced obviously because of HP.51h after admission, after CWH, IL-1、TNF-α and TGF-(3 levels of blood purification group were lower than that of control group significantly. After HP therapy, paraquat plasma concentration of patients was decreased obviously, by(15.27±9.08) mg/L fell to (3.37±1.95) mg/L. After CVVH therapy, patients’ plasma IL-1、TNF-α、TGF-β levels were reduced significantly. The average survival time of the deaths of blood purification group was higher than that of control group significantly. Howere, no difference in overall mortality was founded between blood purification group and control group.[Conclusion]1. High performance liquid chromatography (HPLC) was used for the determination of plasma concentration of paraquat. In this method, the peak shape of paraquat was good, the retention time was appropriate, both the precision and the recovery meeted requirements of the methodology. And the analysis process was simple, the whole detection process could be finished within 30 minutes. Therefore, HPLC can be applied to rapid detection of plasma concentration of paraquat for poisoning patients with paraquat. So HPLC is great importance for the judgment of clinical condition, treatment and prognosis of paraquat poisoning patients.2. Average paraquat dose of survival group was less than that of death group obviously. On admission to hospital, the plasma level of ALT, AST, DBIL, BUN, CREA, AMY, CK-MB, peripheral blood WBC of the survival group was lower than that of the death group. However, no obvious difference was found in IBIL and neutrophil percentage between survival group and death group. With the help of Logistics regression analysis, plasma concentration of paraquat was found to have obvious influence on patients’ survival. Alveolar epithelial damage, fracture and fusion of the alveolar interval, alveolar interval broadening in some areas and little exudate in alveolar cavity was the morphology change in lung injury. Plasma concentration of paraquat is the key factor to the survival of patients. Initial clinical data can be used to preliminarily evaluate the condition of patients with paraquat poisoning, and it can help predict prognosis.3. HP-CVVH can obviously reduce plasma paraquat concentration of patients with paraquat poisoning. And the therapy can reduce the levels of serum cytokines such as IL-1、TNF-α and TGF-β significantly. HP-CVVH has a certain effect in the treatment of acute paraquat poisoning, and it can prolong the survival time of poisoning patients. However, the study showed that HP-CVVH could not reduce the mortality of patients with paraquat poisoning.