Oxygen deficit and irreversible hemorrhagic shock

A device was constructed to record continually the oxygen consumption of a dog and to summate as the oxygen deficit the difference between normal oxygen use and oxygen use during hypotension. Dogs were subjected to hypotension of 30 mm Hg and various oxygen deficits were allowed to accumulate. It was found that oxygen deficits of 100 mg/kg or less were not lethal. Oxygen deficits of 120 ml/kg produced an ld 50 , and oxygen deficits of 140 ml/kg or greater were invariably fatal. Digitalization was beneficial to the dogs. Dibenzylene and conditioning of the animals to periods of hypotension proved to be of no value when the animals were subjected to a definite oxygen deficit equal to that in control animals. Neither epinephrine nor norepinephrine changed the mortality rate for a given oxygen deficit.