A 69-year-old man with severe COPD presents with worsening dyspnea. Vital signs show BP 152/88 mm Hg, HR 102/min, RR 28/min, temperature 37.2°C, and SpO2 88% on room air. Arterial blood gas reveals pH 7.36, PaCO2 60 mm Hg, and HCO3− 33 mEq/L. Serum chloride is 98 mEq/L. He denies recent vomiting. Which mechanism best explains the elevated bicarbonate concentration?
- A)Compensation for chronic respiratory alkalosis
- B)Acute intracellular buffering only
- C)Renal retention of bicarbonate in chronic respiratory acidosisGABARITO
- D)Primary metabolic alkalosis from vomiting
- E)Loss of bicarbonate in the urine
Explicação
Chronic CO2 retention in COPD causes chronic respiratory acidosis, and the kidneys compensate over days by increasing bicarbonate reabsorption and net acid excretion. The near-normal pH with elevated PaCO2 and elevated bicarbonate is the classic compensated pa... Ver explicação completa e trilha adaptativa →