Figure 5-14 An air embolus equaling 0.55 mL/kg killed 50% of rabbits breathing oxygen. If the inspired gas mixture contained 75% nitrous oxide, only 0.16 mL/kg was required to kill one half of the animals. (Adapted from Munson ES, Merrick HC: Effect of nitrous oxide on venous air embolism. Anesthesiology 27:783–787, 1966.)