Which of the following statement(s) is/are true concerning carbon monoxide and cyanide exposure?

c. The half-life of carbon monoxide is reduced by a factor of 5 with ventilation with 100% oxygen

Both carbon monoxide and cyanide are commonly inhaled by victims of closed space fires. Patients with significant amounts of carboxyhemoglobin suffer from a marked reduction in their ability to deliver oxygen to peripheral tissues despite a normal arterial partial pressure of oxygen. Its 2.5 hour half-life is reduced by a factor of 5 by ventilation with 100% oxygen. Fire victims who are well ventilated with high concentrations of oxygen by emergency response personnel from the time of extrication commonly have normal carboxyhemoglobin values (< 5%) on initial evaluation despite significant exposure to carbon monoxide at the time of injury. Carboxyhemoglobin is not sensed by standard transmission pulse oximetry, so a normal oxygen saturation on such a monitor does not preclude the possibility of significant carboxy-hemoglobinemia.

Hydrogen cyanide, which is commonly present in the smoke of structural fires, interferes with oxidative metabolism at the cellular level resulting in lactic acidosis. With proper ventilation and fluid resuscitation, the cyanide-induced acidosis corrects in most cases and specific treatment with sodium thiosulfate is not generally required.