Cyanide poisoning causes

Anoxia According to Gordon (1944) the stoppage of vital functions depend upon tissue anoxia. Anoxia means "lack of oxygen". It may be: (1) Anoxic anoxia: In this type, oxygen cannot reach the blood, because of lack of oxygen in the lungs. This occurs: (a) from breathing in a contaminated atmosphere, e.g., from exposure to the fumes in wells and tanks, or from exposure to sewer gas, (b) from mechanical interference with the passage of air into or down the respiratory tract, e.g., in smothering, choking, hanging, strangulation, drowning, traumatic asphyxia and ceain forms of acute poisoning. (2) Anaemic anoxia: In this type, oxygen-carrying capacity of the blood is reduced, e.g., acute massive haemorrhage, poisoning by carbon monoxide, chlorates, nitrates, coaltar derivatives. (3) Stagnant anoxia: In this type, impaired circulation results in a reduction of oxygen delivery to the tissues, e.g., hea failure, embolism and shock. ( 4) Histotoxic anoxia: In this type, the enzymatic processes by which the oxygen in the blood is used by the tissues are blocked, e.g., acute cyanide poisoning. Ref:- k s narayan reddy; pg num:-137