PATHOPHYSIOLOGY OF DISEASE: AN
INTRODUCTION TO CLINICAL MEDICINE
8TH EDITION
AUTHOR(S)GARY D. HAMMER; STEPHEN J.
MCPHEE
TEST BANK
1
Reference
Ch. 1 — Homeostasis and Disease
Question Stem
A 68-year-old man with type 2 diabetes presents with confusion
and deep, rapid respirations. His arterial blood gas shows pH
7.25, HCO₃⁻ 16 mEq/L, PaCO₂ 30 mmHg. Which
pathophysiologic principle best explains his respiratory pattern?
Options
A. Respiratory acidosis from hypoventilation
B. Metabolic acidosis with respiratory compensation
,C. Primary respiratory alkalosis with renal compensation
D. Mixed metabolic alkalosis and respiratory acidosis
Correct Answer
B
Rationales
• Correct (B): The low HCO₃⁻ and acidemia indicate
metabolic acidosis; the low PaCO₂ with rapid respirations is
a compensatory respiratory alkalosis (hyperventilation) to
raise pH, consistent with physiologic compensation
described in homeostasis concepts.
• Incorrect (A): Respiratory acidosis results from
hypoventilation and would show elevated PaCO₂, not a low
PaCO₂.
• Incorrect (C): Primary respiratory alkalosis would have an
elevated pH with low PaCO₂ and a secondary metabolic
compensation (low HCO₃⁻), but pH here is acidemic.
• Incorrect (D): The arterial gas shows primary metabolic
acidosis with respiratory compensation, not a mixed
alkalosis/acidosis pattern.
Teaching Point
Respiratory hyperventilation compensates for metabolic
acidosis by lowering PaCO₂.
,Citation
Hammer & McPhee (2025). Pathophysiology of Disease (8th
Ed.). Ch. 1.
2
Reference
Ch. 1 — Homeostasis and Disease
Question Stem
A patient admitted for sepsis has blood pressure 78/42 mmHg
and lactic acid 6 mmol/L. Which statement best reflects the
pathophysiologic link between tissue hypoperfusion and lactic
acidosis?
Options
A. Hypoperfusion causes increased mitochondrial oxidative
phosphorylation.
B. Reduced oxygen delivery shifts metabolism toward anaerobic
glycolysis.
C. Lactic acid accumulates due to increased hepatic
gluconeogenesis.
D. Tissue hypoperfusion increases renal excretion of
bicarbonate.
Correct Answer
B
Rationales
, • Correct (B): Inadequate oxygen delivery forces cells to
depend on anaerobic glycolysis, increasing lactate
production — a core pathophysiologic mechanism in
shock.
• Incorrect (A): Oxidative phosphorylation decreases with
hypoxia; it does not increase.
• Incorrect (C): Hepatic gluconeogenesis consumes lactate
(Cori cycle) rather than causing its accumulation; hepatic
dysfunction may impair clearance, but that's not the
primary mechanism here.
• Incorrect (D): Hypoperfusion does not directly increase
renal bicarbonate excretion; renal response to acidosis is
complex and usually tries to conserve bicarbonate.
Teaching Point
Anaerobic glycolysis during hypoperfusion raises lactate levels.
Citation
Hammer & McPhee (2025). Pathophysiology of Disease (8th
Ed.). Ch. 1.
3
Reference
Ch. 1 — Mechanisms of Disease: Cellular Injury and Adaptation
Question Stem
A 55-year-old woman with chronic alcohol use develops
INTRODUCTION TO CLINICAL MEDICINE
8TH EDITION
AUTHOR(S)GARY D. HAMMER; STEPHEN J.
MCPHEE
TEST BANK
1
Reference
Ch. 1 — Homeostasis and Disease
Question Stem
A 68-year-old man with type 2 diabetes presents with confusion
and deep, rapid respirations. His arterial blood gas shows pH
7.25, HCO₃⁻ 16 mEq/L, PaCO₂ 30 mmHg. Which
pathophysiologic principle best explains his respiratory pattern?
Options
A. Respiratory acidosis from hypoventilation
B. Metabolic acidosis with respiratory compensation
,C. Primary respiratory alkalosis with renal compensation
D. Mixed metabolic alkalosis and respiratory acidosis
Correct Answer
B
Rationales
• Correct (B): The low HCO₃⁻ and acidemia indicate
metabolic acidosis; the low PaCO₂ with rapid respirations is
a compensatory respiratory alkalosis (hyperventilation) to
raise pH, consistent with physiologic compensation
described in homeostasis concepts.
• Incorrect (A): Respiratory acidosis results from
hypoventilation and would show elevated PaCO₂, not a low
PaCO₂.
• Incorrect (C): Primary respiratory alkalosis would have an
elevated pH with low PaCO₂ and a secondary metabolic
compensation (low HCO₃⁻), but pH here is acidemic.
• Incorrect (D): The arterial gas shows primary metabolic
acidosis with respiratory compensation, not a mixed
alkalosis/acidosis pattern.
Teaching Point
Respiratory hyperventilation compensates for metabolic
acidosis by lowering PaCO₂.
,Citation
Hammer & McPhee (2025). Pathophysiology of Disease (8th
Ed.). Ch. 1.
2
Reference
Ch. 1 — Homeostasis and Disease
Question Stem
A patient admitted for sepsis has blood pressure 78/42 mmHg
and lactic acid 6 mmol/L. Which statement best reflects the
pathophysiologic link between tissue hypoperfusion and lactic
acidosis?
Options
A. Hypoperfusion causes increased mitochondrial oxidative
phosphorylation.
B. Reduced oxygen delivery shifts metabolism toward anaerobic
glycolysis.
C. Lactic acid accumulates due to increased hepatic
gluconeogenesis.
D. Tissue hypoperfusion increases renal excretion of
bicarbonate.
Correct Answer
B
Rationales
, • Correct (B): Inadequate oxygen delivery forces cells to
depend on anaerobic glycolysis, increasing lactate
production — a core pathophysiologic mechanism in
shock.
• Incorrect (A): Oxidative phosphorylation decreases with
hypoxia; it does not increase.
• Incorrect (C): Hepatic gluconeogenesis consumes lactate
(Cori cycle) rather than causing its accumulation; hepatic
dysfunction may impair clearance, but that's not the
primary mechanism here.
• Incorrect (D): Hypoperfusion does not directly increase
renal bicarbonate excretion; renal response to acidosis is
complex and usually tries to conserve bicarbonate.
Teaching Point
Anaerobic glycolysis during hypoperfusion raises lactate levels.
Citation
Hammer & McPhee (2025). Pathophysiology of Disease (8th
Ed.). Ch. 1.
3
Reference
Ch. 1 — Mechanisms of Disease: Cellular Injury and Adaptation
Question Stem
A 55-year-old woman with chronic alcohol use develops
