Therefore, your PR interval may or may not be short and I wouldn't worry until you receive a full report. The PR interval is short in children and lengthens as we get older. A normal value in adults is 120 to 200 milliseconds. It is however shorter than 120ms in approximately 2 to 4% of the adult population.
It is SaO2 that measures oxygen saturation of hemoglobin, and it should be clear that it depends on the partial pressure of arterial oxygen. If PaO2 drops, there's less dissolved oxygen, and therefore less saturation of hemoglobin with oxygen.
2. Examine the PCO2 number on your report. This number is the amount of carbon dioxide in the blood. It is the respiratory component in acid-base balance. It is measured in millimeters of mercury (mmHg). The normal level for PCO2 is between 35 to 45 mmHg.1  The condition of respiratory alkalosis is present if the PCO2 number is below 35 mmHg. 2  This means there is too little carbon dioxide in the blood. 3  A person with this condition can be breathing very fast (hyperventilating).he normal level for PCO2 is between 35 to 45 mmHg. 1  The condition of respiratory alkalosis is present if the PCO2 number is below 35 mmHg. 2  The condition of respiratory acidosis is present if the PCO2 number is above 45 mmHg.