Adequate pulmonary ventilation during anesthesia is essential for maximum protection of the patient during surgical operations. Allbritten, Haupt, and Amadeo1 have shown that a decrease in effective pulmonary ventilation frequently occurs during anesthesia and that a considerable increase in the minute volume of ventilation is required to provide a consistently adequate pulmonary ventilation. They also demonstrated that consistently adequate pulmonary ventilation could be provided without excessive airway pressure by assisting the deflation phase of respiration as well as the inflation phase during anesthesia. Adequacy of ventilation was directly related to ventilatory volume. As an outgrowth of this interest in the importance of the volume of pulmonary ventilation during anesthesia, this present study was conducted to show the relationship of lung volume to airway pressure both in the conscious patient and in the anesthetized patient undergoing surgical operation and to determine what factors influence this relationship.
Rohrer and co-workers2