The conduction zone, from the nose to the respiratory bronchioles, is dead space. Therefore, reduction in the dead space.Īdministration of bronchodilator increases dead space. The size of the ET tube is smaller than the trachea. Intubation decreases dead space by 70 ml approx.

In upright position, there is decreased perfusion to the uppermost alveoli. Supine position decreases dead space and the dead space increases in upright position. Neck extension and jaw protrusion can increase the dead space twofold. Therefore, physiological dead space will also be decreased. Why?įlexion of head decreases anatomical dead space. Alveolar dead space is the volume of gas within unperfused alveoli (and thus not participating in gas exchange either) it is usually negligible in the healthy, awake patient.įlexion of the head decreases dead space. Anatomic dead space is the volume of gas within the conducting zone (as opposed to the transitional and respiratory zones) and includes the trachea, bronchus, bronchioles, and terminal bronchioles it is approximately 2 mL/kg in the upright position.

Physiologic or total dead space is the sum of anatomic dead space and alveolar dead space.

Physiologic dead space decresed