Hypoxemia does not depend on:
C i.e. HbAerial hypoxemia is defined as an aerial Poe (paial pressure of oxygen) less than 80 mmHg, who is breathing room air at sea level. And because the paial pressure of a gas is determined by the soluble fraction of gas and not by the amount carried chemically bound to hemoglobin - the Hb does not determine P02 and hypoxemia does not depend on Hb levelQ.- In CO poisoning effective hemoglobin that can carry 02 decreasesQ (because CO occupies Hb binding site) since P02 or aerial blood O2 remains normalQ, peripheral chemoreceptors are not stimulated and hyperventilation is not seen. In hypoxia, with the reduction of PO2 cerebral blood flow increases (d/t vaso dilatation)Q to maintain O2 delivery in the brain.The cerebral coex can tolerate acute hypoxia for 5-10 min at 28deg0:2, 20 min at 20degC, and 50 min at 50degC.- Hypoxic ischemia almost invariably involve hippocampus. The hippocampal CA1 neurons are vulnerable to even brief episodes of hypoxic ischemia.Hypoxemia & Hypoxia- Hypoxemia means low aerial oxygen tension in blood (i.e. low Pao2). Aerial hypoxemia is defined as an aerial paial pressure of O2 (i.e. Pao2) < 80 mmHg in an adult who is breathing room air at sea level.- Hypoxia is O2 deficinecy at the tissue level to carry out normal metabolic functions and often occurs when Pao2 is less than 60 mmHg. Anoxia means no O2 at all left in the tissue.-Hypercapnia is an increase in paial pressure of aerial CO2 (Paco2) above the normal range (40 + 2 mmHg) and hypocapnia is abnormally low Paco2 (< 35 mmHg).
PaCO2
Altitude
Hb
FIO2