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? A) Excessive time since sample collection B) Exposure of the blood sample to air C) Excessive heparin in the sample D) Sample admixture with venous blood

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Quizplus · Accepted Answer

The PaO2 and PaCO2 values in this sample suggest exposure to air, a common error that can occur during sample collection or handling. Excessive time since sample collection (A) could lead to decreased PaO2 and increased PaCO2, but not to the values observed in this patient. Excessive heparin (C) would affect the coagulation status of the blood but not the gas values. Sample admixture with venous blood (D) would cause a mixed venous-arterial blood gas result, with a lower PaO2 and higher PaCO2 than observed in this case.

When Analyzing an ABG Sample from a Patient with Acute