Fraction of inspired oxygen fio 2 is the molar or volumetric fraction of oxygen in the inhaled gas medical patients experiencing difficulty breathing are provided with oxygen enriched air which means a higher than atmospheric fio 2 natural air includes 21 oxygen which is equivalent to fio 2 of 0 21.
Fio2 room air ค อ.
Now we have a simple face mask.
Now consider you are receiving 10 l min of oxygen via a face mask at an fio2 of 100.
Different devices deliver to the patient more or less of a of what is coming in from the tank.
Impair pulmonary gas exchange ค อม ความผ ดปกต ในการแลกเปล ยนแก สของปอด ซ งม กลไกต างๆได แก o hypoventilation o diffusion defect o v q abnormality o shunt hypoxemia.
Everybody breathing 100 oxygen via nrb will have an pao2 500.
The fio2 coming from a portable oxygen concentrator can vary anywhere from 90 96 fio2.
The natural air we breathe contains 21 oxygen 21 fio2 and 79 nitrogen at all times with some trace gases.
If you are breathing in normally at a peak inspiratory flow rate of 30 l min at room air with an fio2 of 21 you can easily calculate the average fio2 you are breathing in an almost redundant formula.
Up to 1 00 which means 100 oxygen.
How is the 40 60 of oxygen calculated from 1 6l min.
Hospital grade oxygen found in a medical facility can reach 99 fio2.
Of room air plus the oxygen from the supplemental device.
So now you can figure out the max pao2 on any fio2.
Everybody breathing room air 21 will have an pao2 100.
97 p a o 2 100 mmhg tissue requires at least 10 mmhg at mitochondria venous blood p v o 2 40 mmhg o 2 content of expired air 16 3.
Fio2 p f ratio pao2.
30 x 21 630 630 30 21.
These masks cover the patients nose and mouth and offer fio2 rates from 40 60 at 1 6 l min.
Fio2 fraction of inspired oxygen o 2 content of air 20 93 po 2 160 mmhg alveolar air 14 2 p a o 2 104 mmhg arterial blood sat.
So room air administered o2 fio2.
Fio2 aka the amount of air they are actually getting.
P f ratio 100 0 2 500.
We can never accurately know what the fio 2 of a patient is unless we accurately know what their peak inspiratory flow is or we are delivering high flow oxygen at a.
From these ranges most oxygen concentrators can deliver 90 fio2.