Posture/Positioning- Dead space decreases with the supine position increases during the sitting position.Age- extrathoracic causes in infants and children increase dead space compared to adults.Though anatomical dead space is considered a fixed quantity, the patient’s age, posture, and pathology can affect the actual measurement. => anatomical dead space increases by 20mL for each L of lung volumeĮ.g.Fowler’s dead space measurement is dependent on the patient’s size. => at infancy, anatomical dead space is higher for body weight (3.3mL/kg) => modified: V D/V T = (P aCO2 - P ECO2)/P aCO2Īdditional notes Factors influencing anatomical dead space NB: P ECO2 is the partial pressure in MIXED expired gas, NOT end-tidal gasĮnghoff modification - using measured arterial PaCO2 as an estimate of the ideal alveolar PACO2
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |