ABG in acute asthma typically shows which pattern?

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Multiple Choice

ABG in acute asthma typically shows which pattern?

During an acute asthma attack, the pattern on ABG is driven by ventilatory changes: acute alveolar hyperventilation with hypoxemia. The airways constrict and work of breathing increases, so the patient tends to hyperventilate to try to move air in and out more effectively. This rapid breathing blows off CO2, lowering the PaCO2 and raising the pH, which gives a respiratory alkalosis. At the same time, ventilation-perfusion mismatch from bronchospasm and mucus plugging impairs oxygen transfer, so PaO2 drops, causing hypoxemia. Put together, the ABG shows low CO2 with alkalemia and reduced oxygen tension, characteristic of acute asthma. If fatigue sets in and ventilation falls, PaCO2 can rise, signaling possible impending distress, but the typical early pattern is hyperventilation with hypoxemia.

During an acute asthma attack, the pattern on ABG is driven by ventilatory changes: acute alveolar hyperventilation with hypoxemia. The airways constrict and work of breathing increases, so the patient tends to hyperventilate to try to move air in and out more effectively. This rapid breathing blows off CO2, lowering the PaCO2 and raising the pH, which gives a respiratory alkalosis. At the same time, ventilation-perfusion mismatch from bronchospasm and mucus plugging impairs oxygen transfer, so PaO2 drops, causing hypoxemia. Put together, the ABG shows low CO2 with alkalemia and reduced oxygen tension, characteristic of acute asthma. If fatigue sets in and ventilation falls, PaCO2 can rise, signaling possible impending distress, but the typical early pattern is hyperventilation with hypoxemia.

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