Accession Number : ADP008838

Title :   Physiology and Pathophysiology of Respiratory Arrest by Cyanide Poisoning.

Corporate Author : ARMY MEDICAL RESEARCH INST OF CHEMICAL DEFENSE ABERDEEN PROVING GROUND MD

Personal Author(s) : Klimmek, Reinhard

Report Date : 13 MAY 1993

Pagination or Media Count : 9

Abstract : Respiratory arrest, preceded by hyperventilation, is the primary cause of death in acute cyanide poisoning. Hyperventilation followed by apnea is also observed without intoxication. Hyperventilation and apnea in untoxicated subjects and animals are analysed for the underlying physiological and biochemical changes and compared with those found during cyanide poisoning. The study reveals that the respiratory autoregulation appears to be the same under both conditions. Respiratory arrest is controlled by cerebral PCO2 and can occur without hypoxia or inhibition of cytochrome oxidase. It is postulated that respiratory arrest is a 'desperate act' thrusted on the respiratory neurons by a critical exhaustion of their energy store (ATP) due to the rapid firing in the period of hyperventilation. The point of no return may be reached when anoxia and/or partial inhibition of cytochrome oxidase prevent the neurons from replenishing the ATP store. The formation of Fe3+ cyanide complexes. exemplified by the metHb producer DMAP, appears to give the best results with regard to the restoration of spontaneous respiration. The study of respiratory autoregulation may also be helpful in developing and understanding other therapeutic approaches.

Descriptors :   *ANOXIA, *CYANIDES, *POISONING, ADENOSINE PHOSPHATES, APPROACH, CYTOCHROME OXIDASE, DEATH, HYPERVENTILATION, HYPOXIA, INHIBITION, INTOXICATION, NERVE CELLS, OXIDOREDUCTASES, RESPIRATION, GERMANY.

Subject Categories : Toxicology

Distribution Statement : APPROVED FOR PUBLIC RELEASE