Zusammenfassung der Ressource
Hypoxemia
- 1. Hypoventilation
Anmerkungen:
- - drop in ventilation
-depression of resp. centre in brain
-airway obstruction
-disease of nerves supplying resp. muscles
-thoracic wall injury
- 4. Intrapulmonary shunting: Low V/Q
Anmerkungen:
- -most common
-blood passes thru pulmonary system without being involved in gas exchange--> unoxygenated blood reenters arterial system & dilutes oxygenated blood
-atelectasis, consolidated pneumonia
- 2. Impaired diffusion
Anmerkungen:
- -pathological changes--> poor O2 transfer into arterial blood
-Fick's Law: surface area
-membrane thickness
-Gas solubility- CO2 vs. O2
-pressure gradient
- 3. V/Q mismatch
- High V/Q mismatch= dead space
Anmerkungen:
- -No blood supply
-Ventilation exceeds perfusion
-Pulmonary embolism, cardiac failure
- Low V/Q mismatch: shunt
Anmerkungen:
- -Perfusion exceeds ventilation
-blood passing unventilated alveoli--> doxygenated blood entering arterial system
-atelectasis (collapsed alveoli), pneumonia (consolidated alveoli). asthma (fluid filled alveoli)