When analyzing an ABG sample from a patient with acute respiratory distress syndrome and refractory hypoxemia, you notice a PaO₂ of 141 mm Hg and a PaCO₂ of 14 mm Hg. Which of the following analytic errors should you suspect?

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Quizplus · Accepted Answer

A PaO2 reading of 141 mm Hg and a PaCO2 reading of 14 mm Hg are not physiologically possible and indicate an error in the ABG sample analysis. Exposure of the blood sample to air can lead to falsely elevated PaO2 values due to oxygen diffusing into the sample after collection. It is important to ensure that the sample is collected and analyzed promptly to avoid this error. Excessive heparin in the sample can cause falsely decreased PaCO2 values. Sample admixture with venous blood can also result in inaccurate ABG values but would typically result in a mixed acid-base disturbance rather than an isolated abnormality in PaO2 or PaCO2. Excessive time since sample collection is unlikely to be a factor since the ABG values would typically change very little over the course of a few hours.

When Analyzing an ABG Sample from a Patient with Acute