Which ABG pattern is most consistent with fully compensated respiratory acidosis?

Prepare for the Hurst Readiness Exam 2 with engaging quizzes, flashcards, and detailed explanations. Master your exam with confidence!

Multiple Choice

Which ABG pattern is most consistent with fully compensated respiratory acidosis?

Explanation:
In respiratory acidosis, carbon dioxide builds up because ventilation is inadequate. The body tries to compensate by retaining bicarbonate to counteract the acid, and when compensation is complete, the pH can sit near the normal range even though both CO2 and bicarbonate are elevated. The pattern with a high pCO2 (52), a high HCO3− (32), and a pH around 7.38 fits this scenario: CO2 is elevated, kidneys have increased bicarbonate to compensate, and the pH is essentially normal. This is the hallmark of fully compensated respiratory acidosis. Other patterns show the wrong balance: a low pH with normal CO2 suggests metabolic acidosis; a high pH with normal CO2 and high bicarbonate suggests metabolic alkalosis; a low pH with high CO2 but only modest bicarbonate points to acute respiratory acidosis with incomplete compensation.

In respiratory acidosis, carbon dioxide builds up because ventilation is inadequate. The body tries to compensate by retaining bicarbonate to counteract the acid, and when compensation is complete, the pH can sit near the normal range even though both CO2 and bicarbonate are elevated.

The pattern with a high pCO2 (52), a high HCO3− (32), and a pH around 7.38 fits this scenario: CO2 is elevated, kidneys have increased bicarbonate to compensate, and the pH is essentially normal. This is the hallmark of fully compensated respiratory acidosis.

Other patterns show the wrong balance: a low pH with normal CO2 suggests metabolic acidosis; a high pH with normal CO2 and high bicarbonate suggests metabolic alkalosis; a low pH with high CO2 but only modest bicarbonate points to acute respiratory acidosis with incomplete compensation.

More practice questions