Q. Carbon monoxide poisoning true is
a. It is having 10 times more affinity than oxygen
b. 60 percent is not deadly.
c. Concentration above 10% are dangerous and need observation
d. Concentration above 10% are dangerous and need treatment with pure oxygen
for more than 24 hours
Option A: Affinity of CO for Hb is 200-250 times that of oxygen. It causes a conformational change in Hb molecule and reduces affinity of Hb for O2, shifting the oxyhemoglobin dissociation curve to the left.
Option B: Concentrations less than 10% are usually asymptomatic. Concentrations >60% are fatal. Arterial carboxyhemoglobin level must be obtained because pulse oximetry can be falsely elevated.
Option C: Concentrations above 10 per cent are dangerous and need treatment with pure oxygen for more than 24 hours. Administration of 100% O2 reduces the half-life of CO from 250 minutes in room air to 40 to 60 minutes on 100% oxygen.