Hemorrhage is a cause of death in both combat and civilian
injuries. The specific objectives of this research were: (1) to determine the pathophysiologic effects of combined
injuries from sublethal amounts of an
organophosphate (
soman) along with
hypovolemic shock, and (2) to determine the efficacy of
atropine sulfate and
pralidoxime (2-PAM)
therapy for
organophosphate poisoning when combined
injuries occur. Four groups of six beagle dogs/group were used: Group V/H, vehicle administration followed by
hemorrhage; Group S/H,
soman administration followed by
hemorrhage; Group S/A/H,
soman followed by
antidote (
atropine and 2-PAM) and then
hemorrhage; and Group S,
soman only.
Acetylcholinesterase (AChE) activity, hemodynamic parameters, regional blood flow, plasma
enzyme, and hematological changes were monitored.
Soman rapidly decreased AChE activity in RBCs, plasma, and brain tissue. Treatment with
atropine and
2-PAM resulted in only slight reactivation of AChE; they helped maintain blood
gases,
cortisol, plasma
enzymes, inspiratory volume, and blood pressure nearer baseline values. The effects of combined
injuries appear to be greater than those of either injury alone. This was indicated by increased plasma
lactate, plasma
enzymes indicative of tissue damage (
aspartate amine transferase and
creatine kinase), and increased lethality in dogs subjected to both
soman and
hemorrhage (5/12 died). All dogs subjected to only one insult survived the 6-hr experiment.