WGU D236 Pathophysiology Pre-Assessment
(PA) Practice - 2026/2027 | Diagnostic Readiness
Exam | Competency Evaluation
Domain 1: Foundational Concepts (12 Questions)
1. A patient with diabetic ketoacidosis (DKA) would most likely present with which
arterial blood gas (ABG) result?
A. pH 7.50, PaCO₂ 30, HCO₃⁻ 24
B. pH 7.30, PaCO₂ 35, HCO₃⁻ 18
C. pH 7.48, PaCO₂ 48, HCO₃⁻ 32
D. pH 7.32, PaCO₂ 50, HCO₃⁻ 26
Verified Answer: B
Diagnostic Rationale: DKA causes metabolic acidosis (↓ pH, ↓ HCO₃⁻). Option B shows
pH 7.30 & HCO₃⁻ 18 – classic metabolic acidosis with no respiratory compensation yet
(normal PaCO₂), common in acute presentation.
2. A patient with prolonged vomiting has K⁺ 2.8 mmol/L and pH 7.50. The primary
mechanism for the hypokalemia is:
A. Renal K⁺ wasting from metabolic acidosis
B. Gastric fluid loss + metabolic alkalosis → ↑ renal K⁺ secretion
,C. Intracellular shift from insulin excess
D. Decreased dietary intake only
Verified Answer: B
Diagnostic Rationale: **Vomiting = loss of gastric HCl → metabolic alkalosis → ↑ distal
H⁺ secretion → K⁺ loss in urine (B). Option A describes acidosis, C = insulin effect, D is
insufficient alone.
3. A patient with SIADH has Na⁺ 128 mmol/L. The expected urine osmolality is:
A. 100 mOsm/kg (dilute)
B. 450 mOsm/kg (concentrated)
C. 285 mOsm/kg (isotonic)
D. 50 mOsm/kg (very dilute)
Verified Answer: B
Diagnostic Rationale: **SIADH = excess ADH → water retention & concentrated urine (B:
450) despite low serum Na⁺. Options A & D are dilute (inappropriate for SIADH), C =
normal.
4. A patient with burn injury develops compartment syndrome. The cellular event is:
A. Edema within fascia → ↑ pressure → ischemia (correct)
B. Immediate coagulation necrosis only
C. Auto-antibody attack on muscle
D. Venous thrombosis only
, Verified Answer: A
Diagnostic Rationale: **Compartment syndrome = edema in closed fascial space → ↑
pressure → ↓ perfusion (A). B = third-degree burn, C = autoimmune, D is partial.
5. A patient with hereditary hemochromatosis has bronze skin. The cause is:
A. Iron deposition in skin + melanin ↑ (correct)
B. Bilirubin accumulation
C. ACTH cross-reactivity (incorrect; that is Addison)
D. Vitamin D excess
Verified Answer: A
Diagnostic Rationale: **Hemochromatosis = iron deposits + melanin increase → bronze
pigmentation (A). Option C describes Addison’s disease.
6. A patient with Cushing syndrome has hypokalemia. The mechanism is:
A. ↑ aldosterone effect → K⁺ wasting (correct)
B. ↓ renal perfusion
C. ADH excess
D. Metabolic acidosis
Verified Answer: A
Diagnostic Rationale: **Cortisol has mineralocorticoid activity → Na⁺ retention & K⁺ loss
(A). Other options do not cause K⁺ loss.
(PA) Practice - 2026/2027 | Diagnostic Readiness
Exam | Competency Evaluation
Domain 1: Foundational Concepts (12 Questions)
1. A patient with diabetic ketoacidosis (DKA) would most likely present with which
arterial blood gas (ABG) result?
A. pH 7.50, PaCO₂ 30, HCO₃⁻ 24
B. pH 7.30, PaCO₂ 35, HCO₃⁻ 18
C. pH 7.48, PaCO₂ 48, HCO₃⁻ 32
D. pH 7.32, PaCO₂ 50, HCO₃⁻ 26
Verified Answer: B
Diagnostic Rationale: DKA causes metabolic acidosis (↓ pH, ↓ HCO₃⁻). Option B shows
pH 7.30 & HCO₃⁻ 18 – classic metabolic acidosis with no respiratory compensation yet
(normal PaCO₂), common in acute presentation.
2. A patient with prolonged vomiting has K⁺ 2.8 mmol/L and pH 7.50. The primary
mechanism for the hypokalemia is:
A. Renal K⁺ wasting from metabolic acidosis
B. Gastric fluid loss + metabolic alkalosis → ↑ renal K⁺ secretion
,C. Intracellular shift from insulin excess
D. Decreased dietary intake only
Verified Answer: B
Diagnostic Rationale: **Vomiting = loss of gastric HCl → metabolic alkalosis → ↑ distal
H⁺ secretion → K⁺ loss in urine (B). Option A describes acidosis, C = insulin effect, D is
insufficient alone.
3. A patient with SIADH has Na⁺ 128 mmol/L. The expected urine osmolality is:
A. 100 mOsm/kg (dilute)
B. 450 mOsm/kg (concentrated)
C. 285 mOsm/kg (isotonic)
D. 50 mOsm/kg (very dilute)
Verified Answer: B
Diagnostic Rationale: **SIADH = excess ADH → water retention & concentrated urine (B:
450) despite low serum Na⁺. Options A & D are dilute (inappropriate for SIADH), C =
normal.
4. A patient with burn injury develops compartment syndrome. The cellular event is:
A. Edema within fascia → ↑ pressure → ischemia (correct)
B. Immediate coagulation necrosis only
C. Auto-antibody attack on muscle
D. Venous thrombosis only
, Verified Answer: A
Diagnostic Rationale: **Compartment syndrome = edema in closed fascial space → ↑
pressure → ↓ perfusion (A). B = third-degree burn, C = autoimmune, D is partial.
5. A patient with hereditary hemochromatosis has bronze skin. The cause is:
A. Iron deposition in skin + melanin ↑ (correct)
B. Bilirubin accumulation
C. ACTH cross-reactivity (incorrect; that is Addison)
D. Vitamin D excess
Verified Answer: A
Diagnostic Rationale: **Hemochromatosis = iron deposits + melanin increase → bronze
pigmentation (A). Option C describes Addison’s disease.
6. A patient with Cushing syndrome has hypokalemia. The mechanism is:
A. ↑ aldosterone effect → K⁺ wasting (correct)
B. ↓ renal perfusion
C. ADH excess
D. Metabolic acidosis
Verified Answer: A
Diagnostic Rationale: **Cortisol has mineralocorticoid activity → Na⁺ retention & K⁺ loss
(A). Other options do not cause K⁺ loss.
