NURSING PATHOPHYSIOLOGY EXAM #2: ALTERATIONS IN GAS EXCHANGE
(2026/2027) | CASE STUDY & STANDARD QUESTIONS WITH CORRECT ANSWERS
Advanced Pathophysiology Examination: Focus on Respiratory & Hematologic Systems | Core
Domains: Pulmonary Anatomy & Physiology Review, Hypoxia & Hypoxemia Mechanisms, Obstructive
& Restrictive Lung Diseases, Pulmonary Vascular Disorders, ARDS, Gas Transport & Hemoglobin
Disorders, Acid-Base Imbalances, and Clinical Correlation with Diagnostics | Graduate-Level Nursing
Focus | Case Study & Clinical Application Exam Format
Exam Structure
This exam for the 2026/2027 cycle is a 50-question assessment that includes several in-depth case study
questions requiring analysis of patient scenarios, alongside standard multiple-choice items, to test the
integration of respiratory and hematologic pathophysiology with clinical presentation.
Answer Format
All correct answers must be presented in bold and green, followed by rationales that link
pathophysiological mechanisms to the specific clinical findings and diagnostic data presented in the case
studies and questions.
Questions (50 Total)
1.
A patient with severe anemia has a PaO₂ of 95 mm Hg but an SpO₂ of 98% and appears cyanotic.
What type of hypoxia is present?
A. Hypoxic hypoxia
B. Anemic hypoxia
C. Stagnant hypoxia
D. Histotoxic hypoxia
Despite normal PaO₂ and SpO₂, the patient has reduced hemoglobin, limiting oxygen-carrying capacity.
Tissues receive insufficient oxygen, causing functional hypoxia and possible cyanosis due to increased
deoxygenated hemoglobin in capillaries.
2.
A 65-year-old smoker presents with dyspnea, chronic cough, and barrel chest. ABG: pH 7.36, PaCO₂ 58
mm Hg, HCO₃⁻ 32 mEq/L.
,What is the most likely diagnosis?
A. Asthma
B. Chronic bronchitis (COPD)
C. Pulmonary fibrosis
D. Pneumonia
Chronic bronchitis—a form of COPD—is characterized by chronic productive cough and airflow
limitation in smokers. The ABG shows compensated respiratory acidosis, typical of stable COPD. Barrel
chest results from hyperinflation.
3. Atelectasis refers to:
A. Air in the pleural space
B. Collapse of alveoli
C. Fluid in the lungs
D. Chronic airway dilation
Atelectasis is alveolar collapse, often postoperative due to shallow breathing or mucus plugging. It
impairs gas exchange and appears as opacity on chest X-ray. Prevention includes incentive spirometry
and early ambulation.
4.
A postoperative client suddenly develops dyspnea, tachycardia, and pleuritic chest pain. D-dimer is
elevated.
What is the priority action?
A. Administer oxygen and obtain CT pulmonary angiography
B. Administer oxygen and obtain CT pulmonary angiography
C. Start antibiotics
D. Give antacids
This presentation suggests pulmonary embolism (PE). Oxygen supports oxygenation while CT
pulmonary angiography (CTPA) is the gold standard for diagnosis. Anticoagulation should not be
delayed if PE is highly suspected.
, 5.
A client with sepsis develops acute respiratory distress, bilateral infiltrates on CXR, and PaO₂/FiO₂ ratio of
180.
What condition is present?
A. Pneumonia
B. Acute Respiratory Distress Syndrome (ARDS)
C. Pulmonary edema
D. Atelectasis
ARDS is defined by acute onset, bilateral opacities on imaging, non-cardiogenic origin, and PaO₂/FiO₂
≤300 (moderate ARDS: 100–200). It results from inflammatory lung injury causing non-cardiogenic
pulmonary edema.
6. Carbon monoxide (CO) poisoning causes tissue hypoxia primarily by:
A. Reducing PaO₂
B. Binding to hemoglobin with 200x greater affinity than oxygen
C. Causing methemoglobinemia
D. Decreasing cardiac output
CO binds to hemoglobin forming carboxyhemoglobin (COHb), which cannot carry oxygen. It also shifts
the oxyhemoglobin dissociation curve left, impairing oxygen release to tissues—leading to histotoxic
hypoxia.
7.
A patient with diabetic ketoacidosis (DKA) has Kussmaul respirations.
This is a compensatory mechanism for:
A. Metabolic alkalosis
B. Metabolic acidosis
C. Respiratory acidosis
(2026/2027) | CASE STUDY & STANDARD QUESTIONS WITH CORRECT ANSWERS
Advanced Pathophysiology Examination: Focus on Respiratory & Hematologic Systems | Core
Domains: Pulmonary Anatomy & Physiology Review, Hypoxia & Hypoxemia Mechanisms, Obstructive
& Restrictive Lung Diseases, Pulmonary Vascular Disorders, ARDS, Gas Transport & Hemoglobin
Disorders, Acid-Base Imbalances, and Clinical Correlation with Diagnostics | Graduate-Level Nursing
Focus | Case Study & Clinical Application Exam Format
Exam Structure
This exam for the 2026/2027 cycle is a 50-question assessment that includes several in-depth case study
questions requiring analysis of patient scenarios, alongside standard multiple-choice items, to test the
integration of respiratory and hematologic pathophysiology with clinical presentation.
Answer Format
All correct answers must be presented in bold and green, followed by rationales that link
pathophysiological mechanisms to the specific clinical findings and diagnostic data presented in the case
studies and questions.
Questions (50 Total)
1.
A patient with severe anemia has a PaO₂ of 95 mm Hg but an SpO₂ of 98% and appears cyanotic.
What type of hypoxia is present?
A. Hypoxic hypoxia
B. Anemic hypoxia
C. Stagnant hypoxia
D. Histotoxic hypoxia
Despite normal PaO₂ and SpO₂, the patient has reduced hemoglobin, limiting oxygen-carrying capacity.
Tissues receive insufficient oxygen, causing functional hypoxia and possible cyanosis due to increased
deoxygenated hemoglobin in capillaries.
2.
A 65-year-old smoker presents with dyspnea, chronic cough, and barrel chest. ABG: pH 7.36, PaCO₂ 58
mm Hg, HCO₃⁻ 32 mEq/L.
,What is the most likely diagnosis?
A. Asthma
B. Chronic bronchitis (COPD)
C. Pulmonary fibrosis
D. Pneumonia
Chronic bronchitis—a form of COPD—is characterized by chronic productive cough and airflow
limitation in smokers. The ABG shows compensated respiratory acidosis, typical of stable COPD. Barrel
chest results from hyperinflation.
3. Atelectasis refers to:
A. Air in the pleural space
B. Collapse of alveoli
C. Fluid in the lungs
D. Chronic airway dilation
Atelectasis is alveolar collapse, often postoperative due to shallow breathing or mucus plugging. It
impairs gas exchange and appears as opacity on chest X-ray. Prevention includes incentive spirometry
and early ambulation.
4.
A postoperative client suddenly develops dyspnea, tachycardia, and pleuritic chest pain. D-dimer is
elevated.
What is the priority action?
A. Administer oxygen and obtain CT pulmonary angiography
B. Administer oxygen and obtain CT pulmonary angiography
C. Start antibiotics
D. Give antacids
This presentation suggests pulmonary embolism (PE). Oxygen supports oxygenation while CT
pulmonary angiography (CTPA) is the gold standard for diagnosis. Anticoagulation should not be
delayed if PE is highly suspected.
, 5.
A client with sepsis develops acute respiratory distress, bilateral infiltrates on CXR, and PaO₂/FiO₂ ratio of
180.
What condition is present?
A. Pneumonia
B. Acute Respiratory Distress Syndrome (ARDS)
C. Pulmonary edema
D. Atelectasis
ARDS is defined by acute onset, bilateral opacities on imaging, non-cardiogenic origin, and PaO₂/FiO₂
≤300 (moderate ARDS: 100–200). It results from inflammatory lung injury causing non-cardiogenic
pulmonary edema.
6. Carbon monoxide (CO) poisoning causes tissue hypoxia primarily by:
A. Reducing PaO₂
B. Binding to hemoglobin with 200x greater affinity than oxygen
C. Causing methemoglobinemia
D. Decreasing cardiac output
CO binds to hemoglobin forming carboxyhemoglobin (COHb), which cannot carry oxygen. It also shifts
the oxyhemoglobin dissociation curve left, impairing oxygen release to tissues—leading to histotoxic
hypoxia.
7.
A patient with diabetic ketoacidosis (DKA) has Kussmaul respirations.
This is a compensatory mechanism for:
A. Metabolic alkalosis
B. Metabolic acidosis
C. Respiratory acidosis
