TMC THERAPIST MULTIPLE CHOICE
PRACTICE EXAMINATION
2026/2027 Edition
National Board for Respiratory Care (NBRC)
160 Scored Questions + 20 Unscored Pretest Items = 180 Total
Verified Solutions | NGN-Aligned | CRT/RRT Preparation
100% Correct | Graded A+
Based on: NBRC TMC Examination Content Outline 2023-2027 | Egan's Fundamentals of Respiratory Care | Pilbeam's Mechanical
Ventilation | Cairo's Cardiopulmonary Anatomy & Physiology | Des Jardins' Clinical Manifestations | AARC Clinical Practice Guidelines |
ARDSNet Protocol | AHA ACLS Guidelines | ATS/ERS Standards
EXAM INFORMATION & STRUCTURE
Exam Name: Therapist Multiple Choice (TMC) Examination
Administering Body: National Board for Respiratory Care (NBRC)
Testing Format: Computer-based, proctored at Pearson VUE testing centers
Total Items: 180 (160 scored + 20 unscored pretest items)
Testing Time: 3 hours (180 minutes)
Passing Criteria: Two cut scores — CRT threshold (lower) and RRT threshold (higher)
Item Types: Single-best-answer multiple choice and scenario-based items
Question Style: All questions bold | Correct answers bold green | Rationales italic
DOMAIN COVERAGE SUMMARY
Patient Data Evaluation (Q1–Q32) — 32 Questions
Topics: ABG Interpretation, PFTs, Hemodynamic Monitoring, Lab Data, Imaging, Physical Assessment
Equipment/Infection Control/QA (Q33–Q62) — 30 Questions
Topics: Ventilator Circuits, Humidification, Aerosol Devices, Oxygen Delivery, Sterilization, Calibration, Infection Control
Oxygen Therapy & Airway Management (Q63–Q88) — 26 Questions
Topics: Oxygen Therapy Devices/FiO₂, Airway Mgmt, Suctioning, ET Tubes, Tracheostomy, CPAP/BiPAP, CPT
Mechanical Ventilation (Q89–Q130) — 42 Questions
Topics: ACV/SIMV/PSV/PCV/APRV/HFOV, Settings, Alarms, Waveforms, Weaning, ARDSNet Protocol, Neonatal
Ventilation
Respiratory Pharmacology (Q131–Q140) — 10 Questions
Topics: Bronchodilators (SABA/LABA/Anticholinergics), ICS, Mucolytics, NMBAs, Sedatives, Nitric Oxide, Prostacyclin
,Cardiopulmonary Pathophysiology (Q141–Q150) — 10 Questions
Topics: COPD, Asthma, CHF, ARDS, PE, Restrictive Disease, GBS, Myasthenia Gravis, Neonatal RDS
Patient Education & Care Coordination (Q151–Q152) — 2 Questions
Topics: Home Oxygen Safety, Pulmonary Rehabilitation, Smoking Cessation, Inhaler Technique
Special Populations & Clinical Scenarios (Q153–Q154) — 2 Questions
Topics: Neonatal/Pediatric Respiratory Care, Geriatric Considerations, Trauma Management
Safety & Emergency Response (Q155–Q156) — 2 Questions
Topics: Fire Safety, Code Blue/Rapid Response, Equipment Emergency Protocols
Legal/Ethical Responsibilities (Q157–Q158) — 2 Questions
Topics: Scope of Practice, Documentation, Informed Consent, Patient Rights
NGN Clinical Decision-Making (Q159–Q160) — 2 Questions
Topics: Scenario-Based Clinical Decision-Making, Ordered Response, SATA Items
Unscored Pretest Items: Q161–Q180 (20 items; indistinguishable from scored items on actual exam)
1. A respiratory therapist reviews the following ABG results: pH 7.30, PaCO2 50 mmHg,
PaO2 65 mmHg, HCO3- 24 mEq/L. Which interpretation is correct?
A. Uncompensated respiratory acidosis
B. Partially compensated respiratory acidosis
C. Metabolic alkalosis with respiratory compensation
D. Fully compensated respiratory acidosis
Rationale: The ABG shows pH 7.30 (below normal 7.35-7.45), PaCO2 50 mmHg (above normal 35-45 mmHg),
and HCO3- 24 mEq/L (normal 22-26 mEq/L). The low pH indicates acidemia, the elevated PaCO2 indicates the
primary cause is respiratory (retention of CO2), and the normal HCO3- indicates no metabolic compensation has
occurred yet. Therefore, this is uncompensated respiratory acidosis, commonly seen in acute ventilatory failure
such as in COPD exacerbation or airway obstruction.
【Patient Data Evaluation】 [MC]
2. A patient's ABG results are: pH 7.52, PaCO2 28 mmHg, PaO2 92 mmHg, HCO3- 22 mEq/L.
Which condition does this represent?
A. Uncompensated metabolic acidosis
B. Acute respiratory alkalosis
C. Chronic respiratory acidosis
D. Metabolic alkalosis
Rationale: The pH is 7.52 (alkaline), PaCO2 is 28 mmHg (low), PaO2 is 92 mmHg (normal), and HCO3- is 22
mEq/L (normal). The alkaline pH with decreased PaCO2 indicates the primary disturbance is respiratory
alkalosis caused by hyperventilation (alveolar hyperventilation). The normal HCO3- confirms no renal
compensation has occurred, making this an acute respiratory alkalosis. Common causes include
anxiety/hyperventilation syndrome, pain, fever, early sepsis, or hypoxemia-driven hyperventilation.
【Patient Data Evaluation】 [MC]
3. A respiratory therapist evaluates a patient with the following ABG: pH 7.34, PaCO2 60
mmHg, HCO3- 32 mEq/L. What is the correct interpretation?
A. Acute respiratory acidosis
B. Partially compensated respiratory acidosis
C. Uncompensated metabolic alkalosis
D. Fully compensated respiratory acidosis
Rationale: The pH 7.34 is slightly below normal (acidemic), PaCO2 60 mmHg is elevated (respiratory acidosis),
and HCO3- 32 mEq/L is elevated above normal (metabolic compensation/renal retention of bicarbonate).
Because the HCO3- has increased in response to chronic CO2 retention but the pH has not fully returned to
normal (not yet 7.35-7.45), this represents partially compensated respiratory acidosis. This pattern is classic for
chronic COPD with acute exacerbation.
【Patient Data Evaluation】 [MC]
4. The following ABG results are obtained: pH 7.25, PaCO2 40 mmHg, HCO3- 15 mEq/L.
Which interpretation is correct?
A. Uncompensated metabolic acidosis
B. Partially compensated metabolic acidosis
C. Respiratory alkalosis with metabolic compensation
, D. Mixed acid-base disorder
Rationale: The pH 7.25 indicates acidemia, PaCO2 40 mmHg is normal, and HCO3- 15 mEq/L is low (normal
22-26 mEq/L). The low pH with decreased HCO3- identifies the primary disorder as metabolic acidosis. The
normal PaCO2 indicates no respiratory compensation has occurred yet. Causes include lactic acidosis, diabetic
ketoacidosis, renal failure, or severe diarrhea. The expected respiratory compensation (PaCO2 decrease per
Winter's formula: 1.5 × HCO3- + 8 ± 2 = 30.5 ± 2) has not yet begun.
【Patient Data Evaluation】 [MC]
5. A patient has the following ABG: pH 7.48, PaCO2 42 mmHg, HCO3- 34 mEq/L. Which
acid-base imbalance is present?
A. Uncompensated respiratory alkalosis
B. Partially compensated metabolic alkalosis
C. Fully compensated metabolic alkalosis
D. Mixed respiratory and metabolic alkalosis
Rationale: The pH 7.48 is above normal (alkalemia), PaCO2 42 mmHg is normal, and HCO3- 34 mEq/L is
elevated. The alkaline pH with elevated HCO3- indicates metabolic alkalosis as the primary disorder. The normal
PaCO2 indicates that respiratory compensation (hypoventilation to retain CO2) has not yet occurred. This
pattern is seen with vomiting, nasogastric suctioning, diuretic use, or excessive bicarbonate administration. The
expected PaCO2 compensation would be 0.7 × change in HCO3- + 21.
【Patient Data Evaluation】 [MC]
6. A respiratory therapist reviews spirometry results: FEV1/FVC ratio 0.62, FEV1 55%
predicted, FVC 88% predicted. Which interpretation is correct?
A. Normal spirometry
B. Obstructive ventilatory defect
C. Restrictive ventilatory defect
D. Mixed obstructive and restrictive defect
Rationale: The FEV1/FVC ratio of 0.62 is below the normal threshold of 0.70 (or less than the lower limit of
normal), indicating an obstructive pattern. The FEV1 at 55% predicted is moderately reduced, while the FVC at
88% predicted is normal or near-normal. This pattern (reduced FEV1/FVC ratio with normal or minimally
reduced FVC) is classic for obstructive lung disease such as COPD or asthma. GOLD guidelines classify this as
moderate airflow obstruction (FEV1 50-79% predicted).
【Patient Data Evaluation】 [MC]
7. Spirometry results show: FEV1/FVC 0.78, FEV1 60% predicted, FVC 62% predicted, TLC
55% predicted. What pattern does this represent?
A. Obstructive ventilatory defect
B. Restrictive ventilatory defect
C. Mixed ventilatory defect
D. Normal spirometry with low effort
Rationale: The FEV1/FVC ratio of 0.78 is above 0.70 (normal), indicating no obstruction. However, both FEV1
(60% predicted) and FVC (62% predicted) are reduced proportionally, and the total lung capacity (TLC) at 55%
predicted is significantly reduced. This pattern of reduced lung volumes (FVC, TLC) with a normal or elevated
FEV1/FVC ratio is characteristic of a restrictive ventilatory defect. Causes include pulmonary fibrosis,
sarcoidosis, obesity, chest wall deformity, or neuromuscular disease.
【Patient Data Evaluation】 [MC]
8. A patient performs a flow-volume loop that shows a concave appearance of the expiratory
limb. What does this finding suggest?
A. Fixed upper airway obstruction
B. Variable extrathoracic obstruction
C. Intrapulmonary obstructive disease
D. Normal flow-volume loop
Rationale: A concave (scooped-out) appearance of the expiratory limb of the flow-volume loop is characteristic
of intrapulmonary obstructive disease such as COPD or asthma. The concavity reflects increased airway
resistance and reduced expiratory flow rates, particularly at mid-to-low lung volumes where small airways
collapse. Fixed upper airway obstruction shows a flattened loop (both inspiratory and expiratory), while variable
extrathoracic obstruction shows inspiratory flattening only.
【Patient Data Evaluation】 [MC]
, 9. A respiratory therapist measures peak inspiratory pressure (PIP/NIF) as -25 cmH2O.
What does this value suggest about the patient's ability to be weaned from mechanical
ventilation?
A. Excellent weaning potential; NIF exceeds -20 cmH2O
B. Poor weaning potential; NIF below -20 cmH2O threshold
C. Inconclusive; NIF must be repeated post-extubation
D. Normal value; no clinical significance
Rationale: The negative inspiratory force (NIF) or maximal inspiratory pressure (MIP) is a measurement of
respiratory muscle strength used to assess weaning readiness. An NIF more negative than -20 to -25 cmH2O (i.e.,
-25 cmH2O) indicates adequate inspiratory muscle strength for spontaneous breathing and successful weaning
from mechanical ventilation. Values less negative than -20 cmH2O suggest weakness and increased risk of
weaning failure and post-extubation respiratory distress.
【Patient Data Evaluation】 [MC]
10. A patient's vital capacity is measured at 8 mL/kg. What does this value indicate?
A. Adequate ventilatory reserve for extubation
B. Borderline; should be combined with other weaning parameters
C. Poor ventilatory reserve; weaning is contraindicated
D. Normal vital capacity for an adult
Rationale: Vital capacity (VC) measures the maximum volume of air a patient can exhale after a maximal
inhalation. A VC of less than 10 mL/kg (or less than 10-15 mL/kg depending on the source) indicates inadequate
ventilatory reserve and suggests the patient is at high risk for weaning failure. Normal VC is approximately 65-
75 mL/kg. A VC of 8 mL/kg is well below the minimum threshold of 10 mL/kg, indicating weaning from
mechanical ventilation is contraindicated at this time.
【Patient Data Evaluation】 [MC]
11. A respiratory therapist interprets a hemodynamic monitoring reading: CVP 8 mmHg,
PAP 25/12 mmHg, PCWP 10 mmHg, CO 4.5 L/min, SVR 1200 dynes·sec/cm⁵. Which
interpretation is most appropriate?
A. Normal hemodynamic values
B. Left ventricular failure
C. Pulmonary hypertension
D. Right ventricular failure
Rationale: All values are within normal ranges: CVP 2-8 mmHg, PAP 15-30/4-12 mmHg, PCWP (PAOP) 6-12
mmHg, CO 4-8 L/min, and SVR 800-1200 dynes·sec/cm⁵. This indicates normal cardiac function and
hemodynamic status. Left ventricular failure would show elevated PCWP (>15 mmHg) and low CO. Pulmonary
hypertension would show elevated PAP. Right ventricular failure would show elevated CVP and PAP.
【Patient Data Evaluation】 [MC]
12. A patient's hemodynamic values show: PCWP 22 mmHg, CO 3.2 L/min, SVR 1500
dynes·sec/cm⁵. Which condition is most likely?
A. Hypovolemic shock
B. Cardiogenic shock
C. Septic shock
D. Normal findings
Rationale: The pulmonary capillary wedge pressure (PCWP) of 22 mmHg is elevated (normal 6-12 mmHg),
indicating left atrial and left ventricular pressure elevation due to pump failure. The cardiac output of 3.2 L/min
is decreased (normal 4-8 L/min), and SVR of 1500 dynes·sec/cm⁵ is elevated (normal 800-1200). This triad of
elevated PCWP (fluid overload/backing up into lungs), decreased CO (poor forward flow), and elevated SVR
(compensatory vasoconstriction) is classic for cardiogenic shock secondary to left ventricular failure.
【Patient Data Evaluation】 [MC]
13. A patient's mixed venous oxygen saturation (SvO₂) is 45%. Which condition is most likely
present?
A. Increased cardiac output
B. Decreased oxygen delivery or increased tissue oxygen consumption
C. Left-to-right cardiac shunt
D. Hypothermia
Rationale: Normal mixed venous oxygen saturation (SvO₂) is 60-80% (typically 65-75%). A SvO₂ of 45% is
significantly decreased, indicating that tissues are extracting more oxygen than usual from the blood. This occurs
PRACTICE EXAMINATION
2026/2027 Edition
National Board for Respiratory Care (NBRC)
160 Scored Questions + 20 Unscored Pretest Items = 180 Total
Verified Solutions | NGN-Aligned | CRT/RRT Preparation
100% Correct | Graded A+
Based on: NBRC TMC Examination Content Outline 2023-2027 | Egan's Fundamentals of Respiratory Care | Pilbeam's Mechanical
Ventilation | Cairo's Cardiopulmonary Anatomy & Physiology | Des Jardins' Clinical Manifestations | AARC Clinical Practice Guidelines |
ARDSNet Protocol | AHA ACLS Guidelines | ATS/ERS Standards
EXAM INFORMATION & STRUCTURE
Exam Name: Therapist Multiple Choice (TMC) Examination
Administering Body: National Board for Respiratory Care (NBRC)
Testing Format: Computer-based, proctored at Pearson VUE testing centers
Total Items: 180 (160 scored + 20 unscored pretest items)
Testing Time: 3 hours (180 minutes)
Passing Criteria: Two cut scores — CRT threshold (lower) and RRT threshold (higher)
Item Types: Single-best-answer multiple choice and scenario-based items
Question Style: All questions bold | Correct answers bold green | Rationales italic
DOMAIN COVERAGE SUMMARY
Patient Data Evaluation (Q1–Q32) — 32 Questions
Topics: ABG Interpretation, PFTs, Hemodynamic Monitoring, Lab Data, Imaging, Physical Assessment
Equipment/Infection Control/QA (Q33–Q62) — 30 Questions
Topics: Ventilator Circuits, Humidification, Aerosol Devices, Oxygen Delivery, Sterilization, Calibration, Infection Control
Oxygen Therapy & Airway Management (Q63–Q88) — 26 Questions
Topics: Oxygen Therapy Devices/FiO₂, Airway Mgmt, Suctioning, ET Tubes, Tracheostomy, CPAP/BiPAP, CPT
Mechanical Ventilation (Q89–Q130) — 42 Questions
Topics: ACV/SIMV/PSV/PCV/APRV/HFOV, Settings, Alarms, Waveforms, Weaning, ARDSNet Protocol, Neonatal
Ventilation
Respiratory Pharmacology (Q131–Q140) — 10 Questions
Topics: Bronchodilators (SABA/LABA/Anticholinergics), ICS, Mucolytics, NMBAs, Sedatives, Nitric Oxide, Prostacyclin
,Cardiopulmonary Pathophysiology (Q141–Q150) — 10 Questions
Topics: COPD, Asthma, CHF, ARDS, PE, Restrictive Disease, GBS, Myasthenia Gravis, Neonatal RDS
Patient Education & Care Coordination (Q151–Q152) — 2 Questions
Topics: Home Oxygen Safety, Pulmonary Rehabilitation, Smoking Cessation, Inhaler Technique
Special Populations & Clinical Scenarios (Q153–Q154) — 2 Questions
Topics: Neonatal/Pediatric Respiratory Care, Geriatric Considerations, Trauma Management
Safety & Emergency Response (Q155–Q156) — 2 Questions
Topics: Fire Safety, Code Blue/Rapid Response, Equipment Emergency Protocols
Legal/Ethical Responsibilities (Q157–Q158) — 2 Questions
Topics: Scope of Practice, Documentation, Informed Consent, Patient Rights
NGN Clinical Decision-Making (Q159–Q160) — 2 Questions
Topics: Scenario-Based Clinical Decision-Making, Ordered Response, SATA Items
Unscored Pretest Items: Q161–Q180 (20 items; indistinguishable from scored items on actual exam)
1. A respiratory therapist reviews the following ABG results: pH 7.30, PaCO2 50 mmHg,
PaO2 65 mmHg, HCO3- 24 mEq/L. Which interpretation is correct?
A. Uncompensated respiratory acidosis
B. Partially compensated respiratory acidosis
C. Metabolic alkalosis with respiratory compensation
D. Fully compensated respiratory acidosis
Rationale: The ABG shows pH 7.30 (below normal 7.35-7.45), PaCO2 50 mmHg (above normal 35-45 mmHg),
and HCO3- 24 mEq/L (normal 22-26 mEq/L). The low pH indicates acidemia, the elevated PaCO2 indicates the
primary cause is respiratory (retention of CO2), and the normal HCO3- indicates no metabolic compensation has
occurred yet. Therefore, this is uncompensated respiratory acidosis, commonly seen in acute ventilatory failure
such as in COPD exacerbation or airway obstruction.
【Patient Data Evaluation】 [MC]
2. A patient's ABG results are: pH 7.52, PaCO2 28 mmHg, PaO2 92 mmHg, HCO3- 22 mEq/L.
Which condition does this represent?
A. Uncompensated metabolic acidosis
B. Acute respiratory alkalosis
C. Chronic respiratory acidosis
D. Metabolic alkalosis
Rationale: The pH is 7.52 (alkaline), PaCO2 is 28 mmHg (low), PaO2 is 92 mmHg (normal), and HCO3- is 22
mEq/L (normal). The alkaline pH with decreased PaCO2 indicates the primary disturbance is respiratory
alkalosis caused by hyperventilation (alveolar hyperventilation). The normal HCO3- confirms no renal
compensation has occurred, making this an acute respiratory alkalosis. Common causes include
anxiety/hyperventilation syndrome, pain, fever, early sepsis, or hypoxemia-driven hyperventilation.
【Patient Data Evaluation】 [MC]
3. A respiratory therapist evaluates a patient with the following ABG: pH 7.34, PaCO2 60
mmHg, HCO3- 32 mEq/L. What is the correct interpretation?
A. Acute respiratory acidosis
B. Partially compensated respiratory acidosis
C. Uncompensated metabolic alkalosis
D. Fully compensated respiratory acidosis
Rationale: The pH 7.34 is slightly below normal (acidemic), PaCO2 60 mmHg is elevated (respiratory acidosis),
and HCO3- 32 mEq/L is elevated above normal (metabolic compensation/renal retention of bicarbonate).
Because the HCO3- has increased in response to chronic CO2 retention but the pH has not fully returned to
normal (not yet 7.35-7.45), this represents partially compensated respiratory acidosis. This pattern is classic for
chronic COPD with acute exacerbation.
【Patient Data Evaluation】 [MC]
4. The following ABG results are obtained: pH 7.25, PaCO2 40 mmHg, HCO3- 15 mEq/L.
Which interpretation is correct?
A. Uncompensated metabolic acidosis
B. Partially compensated metabolic acidosis
C. Respiratory alkalosis with metabolic compensation
, D. Mixed acid-base disorder
Rationale: The pH 7.25 indicates acidemia, PaCO2 40 mmHg is normal, and HCO3- 15 mEq/L is low (normal
22-26 mEq/L). The low pH with decreased HCO3- identifies the primary disorder as metabolic acidosis. The
normal PaCO2 indicates no respiratory compensation has occurred yet. Causes include lactic acidosis, diabetic
ketoacidosis, renal failure, or severe diarrhea. The expected respiratory compensation (PaCO2 decrease per
Winter's formula: 1.5 × HCO3- + 8 ± 2 = 30.5 ± 2) has not yet begun.
【Patient Data Evaluation】 [MC]
5. A patient has the following ABG: pH 7.48, PaCO2 42 mmHg, HCO3- 34 mEq/L. Which
acid-base imbalance is present?
A. Uncompensated respiratory alkalosis
B. Partially compensated metabolic alkalosis
C. Fully compensated metabolic alkalosis
D. Mixed respiratory and metabolic alkalosis
Rationale: The pH 7.48 is above normal (alkalemia), PaCO2 42 mmHg is normal, and HCO3- 34 mEq/L is
elevated. The alkaline pH with elevated HCO3- indicates metabolic alkalosis as the primary disorder. The normal
PaCO2 indicates that respiratory compensation (hypoventilation to retain CO2) has not yet occurred. This
pattern is seen with vomiting, nasogastric suctioning, diuretic use, or excessive bicarbonate administration. The
expected PaCO2 compensation would be 0.7 × change in HCO3- + 21.
【Patient Data Evaluation】 [MC]
6. A respiratory therapist reviews spirometry results: FEV1/FVC ratio 0.62, FEV1 55%
predicted, FVC 88% predicted. Which interpretation is correct?
A. Normal spirometry
B. Obstructive ventilatory defect
C. Restrictive ventilatory defect
D. Mixed obstructive and restrictive defect
Rationale: The FEV1/FVC ratio of 0.62 is below the normal threshold of 0.70 (or less than the lower limit of
normal), indicating an obstructive pattern. The FEV1 at 55% predicted is moderately reduced, while the FVC at
88% predicted is normal or near-normal. This pattern (reduced FEV1/FVC ratio with normal or minimally
reduced FVC) is classic for obstructive lung disease such as COPD or asthma. GOLD guidelines classify this as
moderate airflow obstruction (FEV1 50-79% predicted).
【Patient Data Evaluation】 [MC]
7. Spirometry results show: FEV1/FVC 0.78, FEV1 60% predicted, FVC 62% predicted, TLC
55% predicted. What pattern does this represent?
A. Obstructive ventilatory defect
B. Restrictive ventilatory defect
C. Mixed ventilatory defect
D. Normal spirometry with low effort
Rationale: The FEV1/FVC ratio of 0.78 is above 0.70 (normal), indicating no obstruction. However, both FEV1
(60% predicted) and FVC (62% predicted) are reduced proportionally, and the total lung capacity (TLC) at 55%
predicted is significantly reduced. This pattern of reduced lung volumes (FVC, TLC) with a normal or elevated
FEV1/FVC ratio is characteristic of a restrictive ventilatory defect. Causes include pulmonary fibrosis,
sarcoidosis, obesity, chest wall deformity, or neuromuscular disease.
【Patient Data Evaluation】 [MC]
8. A patient performs a flow-volume loop that shows a concave appearance of the expiratory
limb. What does this finding suggest?
A. Fixed upper airway obstruction
B. Variable extrathoracic obstruction
C. Intrapulmonary obstructive disease
D. Normal flow-volume loop
Rationale: A concave (scooped-out) appearance of the expiratory limb of the flow-volume loop is characteristic
of intrapulmonary obstructive disease such as COPD or asthma. The concavity reflects increased airway
resistance and reduced expiratory flow rates, particularly at mid-to-low lung volumes where small airways
collapse. Fixed upper airway obstruction shows a flattened loop (both inspiratory and expiratory), while variable
extrathoracic obstruction shows inspiratory flattening only.
【Patient Data Evaluation】 [MC]
, 9. A respiratory therapist measures peak inspiratory pressure (PIP/NIF) as -25 cmH2O.
What does this value suggest about the patient's ability to be weaned from mechanical
ventilation?
A. Excellent weaning potential; NIF exceeds -20 cmH2O
B. Poor weaning potential; NIF below -20 cmH2O threshold
C. Inconclusive; NIF must be repeated post-extubation
D. Normal value; no clinical significance
Rationale: The negative inspiratory force (NIF) or maximal inspiratory pressure (MIP) is a measurement of
respiratory muscle strength used to assess weaning readiness. An NIF more negative than -20 to -25 cmH2O (i.e.,
-25 cmH2O) indicates adequate inspiratory muscle strength for spontaneous breathing and successful weaning
from mechanical ventilation. Values less negative than -20 cmH2O suggest weakness and increased risk of
weaning failure and post-extubation respiratory distress.
【Patient Data Evaluation】 [MC]
10. A patient's vital capacity is measured at 8 mL/kg. What does this value indicate?
A. Adequate ventilatory reserve for extubation
B. Borderline; should be combined with other weaning parameters
C. Poor ventilatory reserve; weaning is contraindicated
D. Normal vital capacity for an adult
Rationale: Vital capacity (VC) measures the maximum volume of air a patient can exhale after a maximal
inhalation. A VC of less than 10 mL/kg (or less than 10-15 mL/kg depending on the source) indicates inadequate
ventilatory reserve and suggests the patient is at high risk for weaning failure. Normal VC is approximately 65-
75 mL/kg. A VC of 8 mL/kg is well below the minimum threshold of 10 mL/kg, indicating weaning from
mechanical ventilation is contraindicated at this time.
【Patient Data Evaluation】 [MC]
11. A respiratory therapist interprets a hemodynamic monitoring reading: CVP 8 mmHg,
PAP 25/12 mmHg, PCWP 10 mmHg, CO 4.5 L/min, SVR 1200 dynes·sec/cm⁵. Which
interpretation is most appropriate?
A. Normal hemodynamic values
B. Left ventricular failure
C. Pulmonary hypertension
D. Right ventricular failure
Rationale: All values are within normal ranges: CVP 2-8 mmHg, PAP 15-30/4-12 mmHg, PCWP (PAOP) 6-12
mmHg, CO 4-8 L/min, and SVR 800-1200 dynes·sec/cm⁵. This indicates normal cardiac function and
hemodynamic status. Left ventricular failure would show elevated PCWP (>15 mmHg) and low CO. Pulmonary
hypertension would show elevated PAP. Right ventricular failure would show elevated CVP and PAP.
【Patient Data Evaluation】 [MC]
12. A patient's hemodynamic values show: PCWP 22 mmHg, CO 3.2 L/min, SVR 1500
dynes·sec/cm⁵. Which condition is most likely?
A. Hypovolemic shock
B. Cardiogenic shock
C. Septic shock
D. Normal findings
Rationale: The pulmonary capillary wedge pressure (PCWP) of 22 mmHg is elevated (normal 6-12 mmHg),
indicating left atrial and left ventricular pressure elevation due to pump failure. The cardiac output of 3.2 L/min
is decreased (normal 4-8 L/min), and SVR of 1500 dynes·sec/cm⁵ is elevated (normal 800-1200). This triad of
elevated PCWP (fluid overload/backing up into lungs), decreased CO (poor forward flow), and elevated SVR
(compensatory vasoconstriction) is classic for cardiogenic shock secondary to left ventricular failure.
【Patient Data Evaluation】 [MC]
13. A patient's mixed venous oxygen saturation (SvO₂) is 45%. Which condition is most likely
present?
A. Increased cardiac output
B. Decreased oxygen delivery or increased tissue oxygen consumption
C. Left-to-right cardiac shunt
D. Hypothermia
Rationale: Normal mixed venous oxygen saturation (SvO₂) is 60-80% (typically 65-75%). A SvO₂ of 45% is
significantly decreased, indicating that tissues are extracting more oxygen than usual from the blood. This occurs
