Study On The Effect Of Hemoperfusion With Activated Charcoal On Severely Acute Organophosphorus Pesticide Poisoning

Acute organophosphorus pesticide poisoning often occurs in our country,the amounts of AOPP patients reaching to several ten thousands every year[1]. Classical therapeutic measures against mild and moderate AOPP cases could get a good result, but it was disappointed in treating severe AOPP patients who are associated with a high mortality rate of 10%-20%. The therapeutic manners against AOPP included decreasing the adsorption of toxin and using antidote and supoport treatment. Up to now, the administration of antidote(pralidoxime) and atropine is already performed well, and support treatment also show a preferable look by using machnical ventilation and adept at cardiac pulmonary cerebral resuscitation and so on. Gastric lavage and blood purification such as hemoperfusion were used to decrease the adsorption of toxin. However, hemoperfusion,as extracorporeal poison-eliminated technology, was explored to clinical treatment at 1970' s, and at present, whether or not hemoperfusion with coated acitivated charcoal should be used in eliminating organophosphates is still not sure. Because of excessive kinds of OP and the complexity of clinical symptoms, no comprehensive trials were performed to investigate the effect of hemoperfusion with coated activated charcoal on severly organophosphorus pesticide poisoning. Thus hemoperfusion trials in vitroand on animals and on clinical cases of oral intoxication with organophosphates were examined.Here hemoperfusion trials in vitro was mainly performed. Several kinds of organophosphate pesticides with different poisoning and different adipose-solubility and water-solubility and antidote atropine were added into 0.9% sodium chloride solution respectively. Concentration were chosen which were known to occur in the blood in cases of severe intoxication in man. The contaminated solution was filled into simulated hemoperfusion tract from which it was fed by means of a peristaltic pump(flow rate:300ml/h) through the activated charcoal column, and it was recirculated for 3 hours.We observed the factors such as the curve of organophosphates concentration to time , and the clearance rate, and the saturation time and so on. The DDVP and atropine mixed trials also tested in order to observe the concentration ratio and etc. We choose the kind of organophosphate (DDVP) which was preferably adsorbed by activated charcoal , and use DDVP in blood trials. The following parameters in blood trials were observedrthe DDVP concentration and plasma cholinesterase activity and etc. Hemoperfusion trials in eliminating atropine solution and organophosphate-atropine mixed solution were also examined. The results showed that in the sodium chloride solution trials the activated charcoal gave a good adsorption to organophosphates with different poisoning and different adipose-solubility and water-solubility. The adsorption rate could reach above 90% in 2 hours, and it was not accelerated in following time, and evenit showed a decendant tendency. The high concentration the OP was, the fast the activated charcoal adsorbed. In blood trials the plasma cholinesterase activity got a remarked improvement whereas it decreased in the control group. The DDVP plasma concentration showed no change, but the solution which was pulled off the activated charcoal column showed that the adsorption rate was about 30% or so. The adsorption of DDVP by activated charcoal was higher than that of atropine. The concentration of DDVP should be 2. 272ug/ml yet the actual concentration was 0. 4138 ug/ml.According to the results of sodium chloride solution trials, it is considered that activated charcoal can perfectly adsorb different kinds of OP with different poisoning and different adipose-solubility and water-solubility;the high concentration the OP was, the fast the activated charcoal adsorbed ;hemoperfusion time should be controlled in 2 hours in order to prevent the release of OP from activated charcoal;the adsorption of DDVP by activated charcoal was higher than that of atropine. According to the results of fresh human blood trials , hemoperfusion with activated charcoal can adsorb a part of DDVP in the blood;to a certain concentration of DDVP, hemoperfusion can greatly improve the plasma cholinesterase activity by cleaning some DDVP; the adsorption of DDVP by activated charcoal was higher than that of atropine in the blood; the adsorption of activated charcoal to DDVP in blood was greatly lower than that in 0. 9% sodium chloride solution,according to the conclusion that the adsorption of middle-molecular and high-molecular weight solutes is particularly...