ABSTRACT
The effects of acute hemorrhage complicated with cyanide posisoning on the hemodynamics were studied and compared with those simple cyanide poisoning in 24 dogs.Cyanide poisoning was induced by intravenous injection a lethal dose of NaCN of 2.5mg/kg,Acute hemorrhage was created by bleeding the dogs to an arterial pressure of 9.33 kPa(70mm Hg)within 2 minutes through a cannulated femoral artery.HR,CO,MAP,LVP,LVP (?)dp/bt max,and ECG were recorded.It was found that the excitatory response of cardiovascular functions was observed within 1 minute after cyanide poisoning,then a significant failure of the cardiavascular functions resulted in the rapid death of the animal 7~10 minutes after cyanide administration.In case when cyanide poisoning was complicated with acute hemorrhage,no excitatory response of the cardiovascular functions could be observed.An early cardiovascular collapse occurred which was characterized by a rapid fall of CO,MAP,LVP,LVP(?)dp/dt max as well as arrhythmia.All the dogs in this group died of acute failure of cardiovascular functions 4- 6 minutes after cyanide poisoning.The results of this study suggest that the failure of the cardiovascular functions is the main cause of death in case of acute hemorrhage complicated with cyanide poisoning.
ABSTRACT
Stroma-free methemoglobin solutions were prepared from dog and pig red blood cells. The procedure is based on oxidizing the ferrous iron in hemoglobin solution to the ferric state. Then all the cell membrane components (i.e.stroma) were removed through crystallization of the hemoglobin molecule in high ionic phosphate buffer, dialysis and repeated washing of crystals prior to solubilization. This method is feasible and reproducible. The methemoglobin solution obtained had similar potassium, sodium, chloride ion concentration and pH value as normol serum. Spectral maxima and minima were characteristic for methemoglobin.SFMS proved to be an effective antidote for cyanide intoxication. Its protection ratio was calculated to be 2.25 while the rats were treated with SFMS equal to 7 % of their total body hemoglobin. The potential advantages of SFMS over current antidotes include its immediate action with cyanide and doesn't compromise any of the patient's oxygen carrying capacity. In preliminary work, SFMS was given at levels of 4-10% total hemoglobin with little adverse effects.