[Experimental treatment of respiratory failure caused by omethoate poisoning in rats].

OBJECTIVE

To examine the therapeutic effect of combined use of pralidoxime-Cl and atropine with artificial ventilation on respiratory muscle paralysis caused by omethoate poisoning in rats.

METHODS

Rats were administered with same doses of 2LD(50) omethoate and then treated with atropine (10 mg/kg) to resist effectively chlolinergic symptoms. When the rats had slow respiratory frequency and breathed with difficulty, the trachea was intubated and artificial ventilation was carried out (except for group A). The rats in group B were continuously treated with atropine. The doses of pralidoxime-Cl for group C, D and E were 15 mg/kg, 20 mg/kg and 40 mg/kg respectively, given at the same time as artificial ventilation and 1, 2 and 3 hours later. The dose of atropine was reduced to 1/3 to 2/3 of the first dose so as to maintain the rats atropinized. If the rat survived beyond 60 minutes after withdrawal of artificial ventilation, the combined treatment was considered successful. The function of isolated phrenic diaphragm of the rats was observed with MS-302 analyses instrument physiologically and pharmacologically.

RESULTS

None of the rats in group B successfully withdraw from artificial ventilation. The rats in group C all successfully withdraw from artificial ventilation in 3 hours and the function of the isolated phrenic muscle remained good. The survival rats in group D and E were very low after withdrawal, even though the function of isolated phrenic muscle was good.

CONCLUSIONS

The therapeutic effect of the combined use of suitable dose of pralidoxime-Cl and atropine with artificial ventilation on respiratory muscle paralysis caused by omethoate poisoning in rats was significant. This measure can facilitate reversal of the function of poisoned diaphragm and reduced the death rate in poisoned rats.