• Hyperventilation, useful in preventing or treating atelectasis, was induced by having patients breathe through a sufficiently long tube. A rubber tube with internal diameter of 3.2 cm. and length of 125 cm. was found to add 1,000 cc. to the physiological dead air space and it more than doubled the patient's initial tidal volume. Increasing the volume of the tube caused corresponding increases in the carbon dioxide content of alveolar air and the respiratory minute volume without much rate change. Blowing 100% oxygen into the open end of the tube prevented hypoxia without abolishing the hyperpnea and showed that the alveolar carbon dioxide was the critical factor. The effectiveness of the deadspace rebreathing tube for inducing hyperpnea has been tested in more than 1,000 cases. This device is more effective than the paper bag and less expensive than carbon dioxide. It is recommended for both the prevention of postoperative atelectasis and the treatment of established atelectasis.
Schwartz SI, Dale WA, Rahn H. DEAD-SPACE REBREATHING TUBE FOR PREVENTION OF ATELECTASIS. JAMA. 1957;163(14):1248-1251. doi:10.1001/jama.1957.02970490046010