5 causes of hypoxemia

A-a gradient normal (less than 15mmhg) ✅

4) hypoxic mixture or reduced fio2

5) hypoventilation

A-a gradient increased

2) diffusion limitation

3) V/Q mismatch

1) shunt

difference between

PAO2 alveolar oxygen

paO2 arterial oxygen

determines cause of hypoxemia

fixed with supp. O2

fixed with supp. O2

not fixed with supp. O2

fixed with supp O2

fixed with supp O2

not enough o2 in inspired gas

inadequate air transfer in and out of lungs

pulmonary blood bypasses alveoli

capillary thickening hinders O2 diffusion

poor matching of V/Q

wide variation between PAO2 and paO2 =significant shunt

will be A-a gradient increased

PULMONARY EDEMA

PULMONARY FIBROSIS

COPD

OPIOID OVERDOSE

HIGH ALTITUDE