Blood gas – respiratory failure — RACP Paediatrics MCQ

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EasyEmergencyBlood gas – respiratory failureRACP Paediatrics

A child presents with acute respiratory distress and suspected respiratory failure. What bedside investigation provides the most comprehensive assessment of gas exchange and acid-base status?

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Correct answer: E — Blood gas (capillary/arterial)

Blood gas analysis (capillary, arterial, or venous) provides: pH, pCO2 (ventilation adequacy), pO2 (oxygenation – arterial only), bicarbonate, base excess, and lactate. It rapidly identifies: respiratory failure (type 1 or 2), metabolic acidosis, and mixed acid-base disorders. Capillary blood gas is most commonly used in children; arterial for accurate pO2 assessment.

Reference: RCH Melbourne – 2023 – Respiratory Failure CPG; RACP Paediatric Curriculum – Emergency