Tracheostomy and respiratory dead space in emphysema

Abstract
Acute experimentation to judge the effects of reduction of dead space with tracheostomy breathing was performed on four subjects with lower airway obstruction (bronchitis and emphysema) and on two subjects with upper airway obstruction (carcinoma of the larynx and tracheal stenosis). With tracheostomy breathing, the reduction in dead space led to a decrease in minute ventilation except in the two patients with upper airway obstruction. Alveolar ventilation decreased except when alveolar hypoventilation was present to start with. There was no change or an increase in Pacoco2 and H+ in the subjects with lower airway obstruction and small increases in arterial oxygen saturation and Paoo2 occurred. A decrease in Pacoco2 and H+ occurred in one of two patients with upper airway obstruction. Reduction of dead space per se with tracheostomy breathing brings about small changes in alveolar ventilation and gas exchange in the lungs of patients with chronic bronchitis and emphysema. Note:(With the Technical Assistance of Roy Engstrom, Mabel Pearson, and Tom Purcell) physiological dead space and tracheostomy; arterial blood gases with tracheostomy breathing; tracheostomy versus mouth breathing; emphysema and tracheostomy breathing Submitted on February 11, 1963