You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Aerial blood gas of a 5 year old child done at sea level gives the following results: pH 7.41, PaO2, 100 mmHg, and PaCO2, 40 mmHg. The child is being ventilated with 80% oxygen. What is the (A-a) DO2.- and explain in detail?
Alveolar air equation: Using the alveolar air equation - PAO2 = - Data: Fraction of O2 in the inspired air = 80% Barometric pressure = 760 mm Hg (sea level) Water vapor pressure = 47 mm Hg Respiratory quotient = 0.8 Hence, Alveolar PO2 = - = 570.4 - 50 = 520.4 mm Hg Aerial PO2 is given = 100 mm Hg Hence, (A - a) DO2 = 520.4 - 100 = 420.4 mm Hg