Inhalation of 75% Nitrous Oxide Rapidly Increases the Volume of a Pneumothorax (Open Symbols)

(From Eger EI II, Saidman LJ. Hazards of nitrous oxide anesthesia in bowel obstruction and pneumothorax. Anesthesiology. 1965;26:61-66, with permission.)

Inhalation of oxygen (solid symbols) does not alter the volume of the pneumothorax.