A middle-aged woman has had asthma since childhood and has been a heavy smoker since her early teens. During the past few years, she has experienced progressive dyspnea (breathing difficulty) and somnolence (sleepiness). Physical examination reveals a cachectic (general ill health and malnutrition) female with shortness of breath, prolonged expirations, and frequent coughing. Laboratory data are as follows: arterial pH 7.35; arterial HCO₃^- 32 mEq/L; arterial PCO₂ 60 mmHg; and arterial PO₂, 60 mmHg. Which of the following is a likely diagnosis? A) Acute metabolic acidosis with renal compensation B) Acute respiratory acidosis without renal compensation C) Chronic metabolic acidosis with considerable renal compensation D) Chronic respiratory acidosis with considerable renal compensation E) Respiratory acidosis with metabolic acidosis

Question

Quizplus · Accepted Answer

The patient's symptoms and laboratory data indicate chronic respiratory acidosis with considerable renal compensation. The elevated arterial PCO2 (60 mmHg) suggests respiratory acidosis, and the normal pH (7.35) alongside an elevated bicarbonate level (32 mEq/L) indicates renal compensation for the chronic respiratory acidosis.

A Middle-Aged Woman Has Had Asthma Since Childhood and Has