Physiological Dead Space

West s zone 1 the difference between anatomical dead space and physiological dead space is alveolar dead space.

Physiological dead space. Alveoli with no perfusion i e. Medical definition of physiological dead space. Alveoli that fill with air but do not exchange gas to and from the capillaries contribute to physiologic dead space which ideally would be very low or almost zero.

Rather than representing it as a volume in ml kg it is better to represent it as a fraction of the tidal volume or minute volume largely because it tends to change together with the tidal volume. Anatomical dead space is that portion of the airways such as the mouth and trachea to the bronchioles which conducts gas to the alveoli. Physiological dead space is the part of the tidal volume which does not participate in gas exchange.

The total dead space in the entire respiratory system including the alveoli compare anatomical dead space. In simple words physiological dead space is the combination of anatomical dead space and alveolar dead space. What is physiological dead space.

Physiological dead space refers to the volume of air that fills conducting airways plus the volume of air that penetrates gas exchanging regions but does not involve in gas exchange. Its volume v d is determined by measuring the partial pressure of carbon dioxide in a sample of exhaled gas peco2 and in the arterial blood paco2 and with tidal volume of v t using the formula v d v t paco2 peco2 paco2. In the respiratory tract any nonfunctional alveoli that do not receive air that participates in gas exchange.

Measuring physiological dead space measure the amount of co2 eliminated from the lung in a single tidal volume collect one tidal volume of gas and measure the mixed expired co2 concentration physiological dead space equation. Dead space is the portion of each tidal volume that does not take part in gas exchange. 2003 by saunders an imprint of elsevier inc.

Possible causes include emphysema pneumothorax pneumonia pulmonary edema and constriction of bronchioles. The total dead space also known as physiological dead space is the sum of the anatomical dead space plus the alveolar dead space. Physiologic dead space the sum of the anatomic and alveolar dead spaces.