## What is the partial pressure of CO2 and O2 in venous blood of a healthy human breathing room air?

approximately 40 to 45 mm Hg

## What should pO2 be on room air?

Room air is assumed to be FIO2 of 20%. A patient has SpO2 of 95% on 5 liters of oxygen. Based on the above information, the SpO2 of 95% is equal to a pO2 of 80 mmHg….Using the P/F Ratio to Identify Acute Respiratory Failure.

P/F ratio on oxygen of = pO2 on room air of
250 50 mmHg
200 40 mmHg
150 30 mmHg

## Is PaO2 the same as SpO2?

SaO2 is oxygen saturation of arterial blood, while SpO2 is oxygen saturation as detected by the pulse oximeter. The partial pressure of oxygen is expressed as PO2, and the partial pressure of arterial blood is expressed as PaO2.

## How do I get PaO2?

The alveolar gas equation is a formula used to approximate the partial pressure of oxygen in the alveolus (PAO2):PAO2=(PB−PH2O)FiO2−(PaCO2÷R)where PB is the barometric pressure, PH2O is the water vapor pressure (usually 47mmHg), FiO2 is the fractional concentration of inspired oxygen, and R is the gas exchange ratio.

## What is a normal fio2?

Natural air includes 21% oxygen, which is equivalent to FiO2 of 0.21. Oxygen-enriched air has a higher FiO2 than 0.21; up to 1.00 which means 100% oxygen. FiO2 is typically maintained below 0.5 even with mechanical ventilation, to avoid oxygen toxicity, but there are applications when up to 100% is routinely used.

## What is normal range for ABG?

Normal Values Partial pressure of oxygen (PaO2) – 75 – 100 mmHg. Partial pressure of carbon dioxide (PaCO2) – 38 – 42 mmHg. Arterial blood pH of 7.38 – 7.42. Oxygen saturation (SaO2) – 94 – 100%

## What is normal PaO2 for COPD?

Persons with COPD are typically separated into one of two catagories: “pink puffers” (normal PaCO2, PaO2 > 60 mmHg) or “blue bloaters” (PaCO2 > 45 mmHg, PaO2 < 60 mmHg). Pink puffers have severe emphysema, and characteristically are thin and free of signs of right heart failure.

## What lab values are important for COPD?

The following laboratory findings may be seen in patients suspected to have COPD.

• Pulse Oximetry.
• Arterial Blood Gas (ABG)
• Hematocrit.
• Blood Test.
• Serum Electrolytes.
• Sputum Culture.
• Human B-type Natriuretic Peptide.
• Alpha 1 Antitrypsin Levels.

## Why do COPD patients have high co2?

Patients with late-stage chronic obstructive pulmonary disease (COPD) are prone to CO2 retention, a condition which has been often attributed to increased ventilation-perfusion mismatch particularly during oxygen therapy.