A female client who has chronic obstructive pulmonary disease (COPD) has presented in the emergency department with cough productive of yellow sputum and increasing shortness of breath. On room air, her blood gases are as follows: pH 7.30 mm Hg, PCO2 60 mm Hg, PO2 55 mm Hg, HCO3 32 mEq/L.
These arterial blood gases reflect:
A . Compensated respiratory acidosis
B . Normal blood gases
C . Uncompensated metabolic acidosis
D . Uncompensated respiratory acidosis
Answer: D
Explanation:
(A) In compensated respiratory acidosis, the pH level is normal, the PCO2level is elevated, and the HCO3level is elevated. The client’s primary alteration is an inability to remove CO2from the lungs, so over time, the kidneys increase reabsorption of HCO3to buffer the CO2.
(B) Normal ranges for arterial blood gases for adults and children are as follows: pH 7.35C7.45, PO280C100 mm Hg, PCO235C45 mm Hg, HCO321C28 mEq/L.
(C) In uncompensated metabolic acidosis the pH level is decreased, the PCO2level is normal, and the HCO3level is decreased. The client’s primary alteration is an inability to remove excess acid via thekidneys. The lungs are unable to clear the increased acid.
(D) In uncompensated respiratory acidosis, the pH level is decreased, the PCO2level is increased, and the HCO3level is normal. In a person with long-standing COPD, the HCO3level will rise gradually over time to compensate for the gradually increasing PCO2, and the person’s pH level will be normal. When a person with COPD becomes acutely ill, the kidneys do not have time to increase the reabsorption of HCO3, so the person’s pH level will reflect acidosis even though the HCO3is elevated.
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