A patient in the emergency department is receiving oxygen via a nonrebreather at 15 L/min. There ABG results are as follows:

This appears to be a typical ABG interpretation question, but after looking at the results, one major value should stand out like a sore thumb.

Before you even attempt to interpret the acid-base status, you should automatically know that a PaO2 of 569 torr on 100% oxygen is not only possible.

The PaCO2 and the Bicarb values are both in the normal ranges. That means that the pH should be normal as well, but it’s not— it’s decreased.

So taking everything into consideration, you know that the only possibility here is a laboratory error. The correct answer has to be C.

The correct answer is: C. Laboratory error