Calculate the PaO2/FiO2 ratio when PaO2 is 260 mmHg and FiO2 is 0.80.

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Calculate the PaO2/FiO2 ratio when PaO2 is 260 mmHg and FiO2 is 0.80.

The PaO2/FiO2 ratio shows how well oxygen moves from the lungs into the blood by dividing the arterial oxygen pressure by the inspired oxygen fraction. With PaO2 = 260 mmHg and FiO2 = 0.80, you compute 260 ÷ 0.80 = 325. So the ratio is 325. A value above 300 generally indicates normal oxygenation given the high FiO2, whereas lower values (200–300, 100–200, <100) are used to gauge levels of oxygenation impairment such as in ARDS.

The PaO2/FiO2 ratio shows how well oxygen moves from the lungs into the blood by dividing the arterial oxygen pressure by the inspired oxygen fraction. With PaO2 = 260 mmHg and FiO2 = 0.80, you compute 260 ÷ 0.80 = 325. So the ratio is 325. A value above 300 generally indicates normal oxygenation given the high FiO2, whereas lower values (200–300, 100–200, <100) are used to gauge levels of oxygenation impairment such as in ARDS.

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