Therapeutic effects of gastric lavage with fuller earth combined with QingyiⅡ catharsis in treatment of oral paraquat poisoning in rabbits / 中华危重病急救医学

ABSTRACT

ObjectiveTo observe the therapeutic effects of gastric lavage with fuller earth combined with QingyiⅡ catharsis in treatment of oral paraquat poisoning in rabbits.Methods Thirty healthy adult Japanese white rabbits were randomly divided into five groups namely control group, model group, gastric lavage group (lavage of 10%fuller earth suspension), catharsis group (QingyiⅡ catharsis), and combination group (10 minutes after gastric lavage of fuller earth suspension liquid, giving QingyiⅡ for catharsis), with 6 rabbits in each group. All groups were challenged with paraquat (100 mg/kg) diluted to 5 mL with normal saline by lavage to reproduce the model of acute poisoning, while the control group was given 5 mL of normal saline instead. Each treatment group was treated accordingly at 1 hour after gavages of paraquat, and treatment continued for 3 days. The animal survival rate was observed. Venous blood samples were collected from ear marginal vein to determine the plasma concentration of paraquat by ultraviolet spectrophotometer at 1, 2, 4, 8 and 24 hours after the poisoning. The animals were sacrificed by intravenous air injection on the 8th day after the poisoning, and the right lower lobe of lung was harvested to observe the lung tissue pathological changes with hematoxylin-eosin (HE) staining.Results① Survival rate the surviving rate of the combination group (6 rabbits) was higher than that of gastric lavage group (5 rabbits), catharsis group (2 rabbits) and model group (0 rabbit) on the 2nd day with statistically significant difference (P< 0.001). The survival rate on the 7th day in combination group (5 rabbits) was higher than that of gastric lavage group (3 rabbits), and catharsis group (0 rabbit) with statistically significant difference (P = 0.003).② Plasma concentrations of paraquat plasma paraquat concentration in all groups peaked at 2 hours after intoxication, and its levels in the gastric lavage, catharsis and combination groups were significantly lower than that of the model group (mg/L 1.830±0.068, 1.890±0.048, 1.800±0.052 vs. 1.960±0.063, allP< 0.01). As the time prolonged, the plasma concentration of paraquat was lowest in combination group than that of gastric lavage group and catharsis group (allP< 0.01). Gastric lavage and catharsis had interaction at 4 hours in combination group [F = 5.194,P = 0.034; the concentrations of paraquat (mg/L) was 0.670±0.057 vs. 1.010±0.018, 1.210±0.052].③ Lung histopathology obvious expansion and hyperemia of the alveolar capillary, widened alveolar septum, a large number of inflammatory cell infiltrations were observed in model group and catharsis group. Lung histopathology was more improved in combination group and gastric lavage group, and it was improved more obviously in combination group than that in gastric lavage group.Conclusions Early start of gastric lavage with fuller earth combined with QingyiⅡ catharsis, can reduce the animal plasma concentrations of paraquat in oral paraquat poisoning rabbits. At the same time, it can alleviate the degree of lung injury and significantly improve survival rates compared with the single gastric lavage or catharsis alone. Gastric lavage with fuller earth combined with QingyiⅡ catharsis can improve the prognosis of animal synergistically.