NBRC TMC – 3 Versions Test Bank
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
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1. A patient with acute respiratory distress has a PaO₂ of 48 mmHg
while breathing room air. Which condition is most directly
indicated by this finding?
a. Hypercapnia
b. Hypoxemia
c. Metabolic alkalosis
d. Respiratory alkalosis
Rationale: PaO₂ reflects the partial pressure of oxygen dissolved in
arterial blood. A PaO₂ of 48 mmHg is significantly below the expected
range and indicates hypoxemia. Hypercapnia would be assessed
primarily through the PaCO₂ value.
, 2. Which arterial blood gas pattern is most consistent with
uncompensated respiratory acidosis?
a. pH 7.50, PaCO₂ 30 mmHg, HCO₃⁻ 24 mEq/L
b. pH 7.30, PaCO₂ 30 mmHg, HCO₃⁻ 18 mEq/L
c. pH 7.30, PaCO₂ 50 mmHg, HCO₃⁻ 24 mEq/L
d. pH 7.50, PaCO₂ 50 mmHg, HCO₃⁻ 30 mEq/L
Rationale: Respiratory acidosis is characterized by a decreased pH and
elevated PaCO₂. In an uncompensated state, the bicarbonate remains
within the normal range. Therefore, pH 7.30, PaCO₂ 50 mmHg, and
HCO₃⁻ 24 mEq/L represent uncompensated respiratory acidosis.
3. Which finding is most characteristic of chronic respiratory acidosis
with renal compensation?
a. Decreased PaCO₂ and decreased HCO₃⁻
b. Increased PaCO₂ and decreased HCO₃⁻
c. Normal PaCO₂ and increased HCO₃⁻
d. Increased PaCO₂ and increased HCO₃⁻
Rationale: Chronic elevation of PaCO₂ causes the kidneys to retain
bicarbonate to buffer the increased acid load. Consequently, both
PaCO₂ and HCO₃⁻ are elevated, while the pH may be closer to normal
than in an acute uncompensated disorder.
, 4. A patient with COPD has a pulse oximeter reading of 86%. What is
the respiratory therapist's most appropriate initial action?
a. Immediately discontinue oxygen therapy
b. Assess the patient and verify the accuracy of the SpO₂ reading
c. Administer sodium bicarbonate
d. Begin chest compressions
Rationale: A low SpO₂ requires assessment of the patient first. The
therapist should evaluate respiratory effort, airway, circulation, probe
placement, perfusion, and other factors that can produce an
inaccurate reading. Treatment should then be based on the patient's
overall condition and prescribed oxygen target.
5. Which parameter is directly measured during spirometry?
a. Residual volume
b. Functional residual capacity
c. Forced vital capacity
d. Total lung capacity
Rationale: Spirometry directly measures volumes and flows involved
in exhalation and inhalation, including forced vital capacity (FVC) and
forced expiratory volume in one second (FEV₁). Residual volume, FRC,
and TLC require additional techniques because they include gas that
cannot be exhaled.
, 6. A patient has an FEV₁ of 1.8 L and an FVC of 3.0 L. What is the
FEV₁/FVC ratio?
a. 40%
b. 50%
c. 60%
d. 80%
Rationale: The ratio is calculated by dividing FEV₁ by FVC and
multiplying by 100. Thus, 1.8 ÷ 3.0 × 100 = 60%. A reduced FEV₁/FVC
ratio is characteristic of an obstructive ventilatory defect.
7. Which pulmonary function pattern is most consistent with
restrictive lung disease?
a. Decreased FEV₁ with markedly decreased FEV₁/FVC ratio
b. Increased FVC with normal TLC
c. Decreased TLC with a normal or increased FEV₁/FVC ratio
d. Increased residual volume with decreased FEV₁/FVC ratio
Rationale: Restrictive disorders reduce the amount of air the lungs can
contain, resulting in a decreased TLC. Because both FEV₁ and FVC
decrease proportionally, the FEV₁/FVC ratio is typically normal or
increased.
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. A patient with acute respiratory distress has a PaO₂ of 48 mmHg
while breathing room air. Which condition is most directly
indicated by this finding?
a. Hypercapnia
b. Hypoxemia
c. Metabolic alkalosis
d. Respiratory alkalosis
Rationale: PaO₂ reflects the partial pressure of oxygen dissolved in
arterial blood. A PaO₂ of 48 mmHg is significantly below the expected
range and indicates hypoxemia. Hypercapnia would be assessed
primarily through the PaCO₂ value.
, 2. Which arterial blood gas pattern is most consistent with
uncompensated respiratory acidosis?
a. pH 7.50, PaCO₂ 30 mmHg, HCO₃⁻ 24 mEq/L
b. pH 7.30, PaCO₂ 30 mmHg, HCO₃⁻ 18 mEq/L
c. pH 7.30, PaCO₂ 50 mmHg, HCO₃⁻ 24 mEq/L
d. pH 7.50, PaCO₂ 50 mmHg, HCO₃⁻ 30 mEq/L
Rationale: Respiratory acidosis is characterized by a decreased pH and
elevated PaCO₂. In an uncompensated state, the bicarbonate remains
within the normal range. Therefore, pH 7.30, PaCO₂ 50 mmHg, and
HCO₃⁻ 24 mEq/L represent uncompensated respiratory acidosis.
3. Which finding is most characteristic of chronic respiratory acidosis
with renal compensation?
a. Decreased PaCO₂ and decreased HCO₃⁻
b. Increased PaCO₂ and decreased HCO₃⁻
c. Normal PaCO₂ and increased HCO₃⁻
d. Increased PaCO₂ and increased HCO₃⁻
Rationale: Chronic elevation of PaCO₂ causes the kidneys to retain
bicarbonate to buffer the increased acid load. Consequently, both
PaCO₂ and HCO₃⁻ are elevated, while the pH may be closer to normal
than in an acute uncompensated disorder.
, 4. A patient with COPD has a pulse oximeter reading of 86%. What is
the respiratory therapist's most appropriate initial action?
a. Immediately discontinue oxygen therapy
b. Assess the patient and verify the accuracy of the SpO₂ reading
c. Administer sodium bicarbonate
d. Begin chest compressions
Rationale: A low SpO₂ requires assessment of the patient first. The
therapist should evaluate respiratory effort, airway, circulation, probe
placement, perfusion, and other factors that can produce an
inaccurate reading. Treatment should then be based on the patient's
overall condition and prescribed oxygen target.
5. Which parameter is directly measured during spirometry?
a. Residual volume
b. Functional residual capacity
c. Forced vital capacity
d. Total lung capacity
Rationale: Spirometry directly measures volumes and flows involved
in exhalation and inhalation, including forced vital capacity (FVC) and
forced expiratory volume in one second (FEV₁). Residual volume, FRC,
and TLC require additional techniques because they include gas that
cannot be exhaled.
, 6. A patient has an FEV₁ of 1.8 L and an FVC of 3.0 L. What is the
FEV₁/FVC ratio?
a. 40%
b. 50%
c. 60%
d. 80%
Rationale: The ratio is calculated by dividing FEV₁ by FVC and
multiplying by 100. Thus, 1.8 ÷ 3.0 × 100 = 60%. A reduced FEV₁/FVC
ratio is characteristic of an obstructive ventilatory defect.
7. Which pulmonary function pattern is most consistent with
restrictive lung disease?
a. Decreased FEV₁ with markedly decreased FEV₁/FVC ratio
b. Increased FVC with normal TLC
c. Decreased TLC with a normal or increased FEV₁/FVC ratio
d. Increased residual volume with decreased FEV₁/FVC ratio
Rationale: Restrictive disorders reduce the amount of air the lungs can
contain, resulting in a decreased TLC. Because both FEV₁ and FVC
decrease proportionally, the FEV₁/FVC ratio is typically normal or
increased.
