A client is admitted to the emergency room with a respiratory rate of 7/min. Arterial blood gases (ABG) reveal the following values: pH 7.22, PaCO2 68 mm Hg, Base excess -2, PaO2 78 mm Hg, Saturation 80 Which of the following is an appropriate analysis of the ABGs?

Choice A rationale Respiratory acidosis fully compensated would require the pH to be back within the normal range of 7.35 to 7.45. In this case, the pH is 7.22, which is clearly acidic. For full compensation to occur, the kidneys would need to have retained enough bicarbonate to neutralize the high PCO2, which has not happened here. Therefore, this analysis is incorrect because the pH remains significantly outside of the physiological homeostatic range for the human body. Choice B rationale Metabolic acidosis is ruled out because the primary cause of the low pH is the elevated PaCO2 of 68 mmHg, not a low bicarbonate level. A respiratory rate of 7 per minute indicates severe hypoventilation, which causes the accumulation of carbon dioxide. In metabolic acidosis, the PaCO2 would typically be normal or low as the lungs try to compensate by blowing off acid, which is the opposite of what is occurring in this clinical case. Choice C rationale This is respiratory acidosis uncompensated because the pH is low at 7.22 and the PaCO2 is high at 68 mmHg, while the metabolic indicators like base excess and bicarbonate have not significantly shifted to correct the imbalance. The normal PaCO2 range is 35 to 45 mmHg. The low respiratory rate of 7 per minute directly leads to CO2 retention. Since the pH is still acidic, the body has not yet compensated for the respiratory failure. Choice D rationale Respiratory alkalosis would involve a pH above 7.45 and a PaCO2 below 35 mmHg, typically caused by hyperventilation. This client is experiencing the exact opposite with a respiratory rate of 7 per minute and an acidic pH. Alkalosis is characterized by a loss of acids or a gain of bases, neither of which is present in a patient who is hypoventilating and retaining carbon dioxide to the point of a 7.22 pH.