Respiratory failure occurs 1) 40 - 50 % of carboxy haemoglobin in blood in carbon monoxide poisoning 2) 70 - 80 % CO2 Concentration in carbon dioxide poisoning

In CO poisoning, respiratory failure occurs at 70 - 80% of carboxyhemoglobin in blood In CO2 poisoning, respiratory failure occurs at 40 - 50% of CO2 concentration in blood Patient with 70-80 % of carboxyhemoglobin in blood presents in coma with depressed or absent reflexes, thready pulse, irregular respiration which results in death. EFFECTs OF CO INTOXICATION : 0-10% - No symptoms 10 - 20% - Mild head ache 20 -30% - Emotional instability 30 -40% - increase head ache, confusion 50 -60% - Mimics drunkenness >70% - coma, death