NBRC TMC / CRT / RRT
2026–2027 Enhanced Respiratory Therapy
Study Guide
Original exam-oriented review inspired by the public preview of a Stuvia study resource
Important: This is an original study guide, not the actual NBRC examination, not an official NBRC publication, and not a
reproduction of a paid test bank. The seller's claims such as “actual exam,” “verified,” or “pass guaranteed” are not
independently established.
Current-transition note: NBRC materials indicate the existing TMC remains the relevant examination through December
31, 2026, while the new Respiratory Therapy Examination takes effect January 2027. Candidates should study against
the official outline for the date they will test.
Designed for: TMC preparation, CRT/RRT decision-making, clinical reasoning, ABG
interpretation, mechanical ventilation, cardiopulmonary disease, neonatal/pediatric care,
pharmacology, diagnostics, and rapid exam review.
NBRC TMC / CRT / RRT 2026–2027 Enhanced Study Guide — Original educational material Page 1
, 1. Source Review & How to Use This Guide
The public Stuvia page describes a 64-page, 2025/2026 resource containing 140 questions, divided into a CRT-oriented
set and a smaller RRT-oriented set. The public preview begins with patient-data and assessment cases involving ABGs,
hemodynamics, P/F ratio, metabolic/respiratory compensation, and pancreatitis severity. The preview also illustrates why
answer validation matters: at least one displayed rationale infers missing Ranson criteria rather than calculating only from
the data actually supplied. That type of reasoning should not be copied into exam preparation.
Study rule: When a question gives incomplete data, do not invent values. Select the answer supported by the information
provided, or recognize that the item is flawed. On a real credentialing examination, use the complete stem and the official
scoring framework.
This guide expands the visible subject matter into a broader, original curriculum. It emphasizes mechanisms, formulas,
clinical patterns, ventilator reasoning, patient safety, and test-taking strategy rather than reproducing source wording.
2. Exam Structure & 2027 Transition
Through December 31, 2026: the NBRC TMC is a 160-item multiple-choice examination: 140 scored items plus 20
pretest items, with three hours allotted. Two cut scores determine whether a passing candidate receives the CRT or RRT
credential from the RT examination pathway.
Beginning January 2027: NBRC's new Respiratory Therapy Examination contains 185 multiple-choice items, including
160 scored items and 25 pretest items, with a four-hour testing period. The new detailed content outline divides the
examination into a Breadth of Knowledge portion (100 items) and a Depth of Clinical Judgement portion (60 items).
Practical implication: A “2026/2027” study product can straddle two different exam structures. Always match your study
plan to your actual test date and the official NBRC outline in force on that date.
3. Patient Data & Clinical Assessment
Primary survey mindset
Prioritize airway, breathing, circulation, mental status, oxygenation/ventilation, work of breathing, and immediate threats. A
respiratory therapist question often asks what should be assessed or addressed first rather than what diagnosis is most
elegant.
Oxygenation vs ventilation
Oxygenation is primarily reflected by PaO2/SpO2 and the effectiveness of gas exchange. Ventilation is reflected by
PaCO2 and alveolar ventilation. A patient can be hypoxemic without being hypercapnic and vice versa.
Trend over isolated values
Compare current ABGs, ventilator pressures, SpO2, respiratory rate, mental status, and hemodynamics with prior values.
A worsening trend can be more clinically important than a single borderline measurement.
Red flags
Sudden increased work of breathing, altered mental status, silent chest in severe asthma, new unilateral absent breath
sounds, rapidly falling blood pressure, severe hypoxemia despite increasing support, and abrupt ventilator-pressure
changes require prompt evaluation.
4. ABG Interpretation & Acid–Base
Six-step method
NBRC TMC / CRT / RRT 2026–2027 Enhanced Study Guide — Original educational material Page 2
, 1) pH: acidemia or alkalemia. 2) PaCO2: respiratory component. 3) HCO3−: metabolic component. 4) Identify the primary
disorder. 5) Check expected compensation. 6) Evaluate oxygenation and clinical context.
Acute respiratory acidosis
PaCO2 rises and pH falls. Acute compensation is approximately +1 mEq/L HCO3− for each 10-mmHg PaCO2 rise above
40.
Chronic respiratory acidosis
Renal compensation is larger: approximately +3.5–4 mEq/L HCO3− per 10-mmHg PaCO2 rise. Chronic COPD with CO2
retention is the classic pattern.
Acute respiratory alkalosis
PaCO2 falls and pH rises; HCO3− falls only modestly. Think hyperventilation from pain, anxiety, hypoxemia, fever,
pregnancy, or early systemic illness.
Metabolic acidosis
HCO3− is low. Use Winter's formula: expected PaCO2 ≈ 1.5 × HCO3− + 8 ± 2. A measured PaCO2 outside the expected
range suggests a second respiratory disorder.
Metabolic alkalosis
HCO3− is high. A common bedside estimate for expected PaCO2 is about 0.7 × HCO3− + 20 ± 5. Excessive deviation
suggests an additional respiratory process.
Anion gap
AG = Na − (Cl + HCO3−). An elevated gap suggests accumulation of unmeasured anions. Interpret with albumin and the
clinical context.
Exam trap
Do not label compensation as a second primary disorder merely because PaCO2 or HCO3− moved in the expected
direction. Compensation is supposed to move in the opposite direction from the primary abnormality.
5. Oxygenation, A–a Gradient & P/F Ratio
P/F ratio
P/F = PaO2 / FiO2, with FiO2 written as a decimal. Example: PaO2 58 on FiO2 0.60 gives approximately 97.
A–a gradient
The alveolar–arterial oxygen gradient helps distinguish hypoxemia due to hypoventilation or low inspired oxygen from
impaired gas exchange such as V/Q mismatch, diffusion limitation, or shunt.
Oxygen delivery
DO2 depends on cardiac output and arterial oxygen content. Hemoglobin concentration and saturation matter; increasing
PaO2 above normal does not linearly increase oxygen content because dissolved oxygen contributes only a small fraction.
ARDS reasoning
In acute hypoxemic respiratory failure, consider P/F ratio, PEEP, chest imaging, timing, and noncardiogenic pulmonary
edema criteria. Avoid diagnosing severity from the P/F number alone without the required clinical context.
NBRC TMC / CRT / RRT 2026–2027 Enhanced Study Guide — Original educational material Page 3
2026–2027 Enhanced Respiratory Therapy
Study Guide
Original exam-oriented review inspired by the public preview of a Stuvia study resource
Important: This is an original study guide, not the actual NBRC examination, not an official NBRC publication, and not a
reproduction of a paid test bank. The seller's claims such as “actual exam,” “verified,” or “pass guaranteed” are not
independently established.
Current-transition note: NBRC materials indicate the existing TMC remains the relevant examination through December
31, 2026, while the new Respiratory Therapy Examination takes effect January 2027. Candidates should study against
the official outline for the date they will test.
Designed for: TMC preparation, CRT/RRT decision-making, clinical reasoning, ABG
interpretation, mechanical ventilation, cardiopulmonary disease, neonatal/pediatric care,
pharmacology, diagnostics, and rapid exam review.
NBRC TMC / CRT / RRT 2026–2027 Enhanced Study Guide — Original educational material Page 1
, 1. Source Review & How to Use This Guide
The public Stuvia page describes a 64-page, 2025/2026 resource containing 140 questions, divided into a CRT-oriented
set and a smaller RRT-oriented set. The public preview begins with patient-data and assessment cases involving ABGs,
hemodynamics, P/F ratio, metabolic/respiratory compensation, and pancreatitis severity. The preview also illustrates why
answer validation matters: at least one displayed rationale infers missing Ranson criteria rather than calculating only from
the data actually supplied. That type of reasoning should not be copied into exam preparation.
Study rule: When a question gives incomplete data, do not invent values. Select the answer supported by the information
provided, or recognize that the item is flawed. On a real credentialing examination, use the complete stem and the official
scoring framework.
This guide expands the visible subject matter into a broader, original curriculum. It emphasizes mechanisms, formulas,
clinical patterns, ventilator reasoning, patient safety, and test-taking strategy rather than reproducing source wording.
2. Exam Structure & 2027 Transition
Through December 31, 2026: the NBRC TMC is a 160-item multiple-choice examination: 140 scored items plus 20
pretest items, with three hours allotted. Two cut scores determine whether a passing candidate receives the CRT or RRT
credential from the RT examination pathway.
Beginning January 2027: NBRC's new Respiratory Therapy Examination contains 185 multiple-choice items, including
160 scored items and 25 pretest items, with a four-hour testing period. The new detailed content outline divides the
examination into a Breadth of Knowledge portion (100 items) and a Depth of Clinical Judgement portion (60 items).
Practical implication: A “2026/2027” study product can straddle two different exam structures. Always match your study
plan to your actual test date and the official NBRC outline in force on that date.
3. Patient Data & Clinical Assessment
Primary survey mindset
Prioritize airway, breathing, circulation, mental status, oxygenation/ventilation, work of breathing, and immediate threats. A
respiratory therapist question often asks what should be assessed or addressed first rather than what diagnosis is most
elegant.
Oxygenation vs ventilation
Oxygenation is primarily reflected by PaO2/SpO2 and the effectiveness of gas exchange. Ventilation is reflected by
PaCO2 and alveolar ventilation. A patient can be hypoxemic without being hypercapnic and vice versa.
Trend over isolated values
Compare current ABGs, ventilator pressures, SpO2, respiratory rate, mental status, and hemodynamics with prior values.
A worsening trend can be more clinically important than a single borderline measurement.
Red flags
Sudden increased work of breathing, altered mental status, silent chest in severe asthma, new unilateral absent breath
sounds, rapidly falling blood pressure, severe hypoxemia despite increasing support, and abrupt ventilator-pressure
changes require prompt evaluation.
4. ABG Interpretation & Acid–Base
Six-step method
NBRC TMC / CRT / RRT 2026–2027 Enhanced Study Guide — Original educational material Page 2
, 1) pH: acidemia or alkalemia. 2) PaCO2: respiratory component. 3) HCO3−: metabolic component. 4) Identify the primary
disorder. 5) Check expected compensation. 6) Evaluate oxygenation and clinical context.
Acute respiratory acidosis
PaCO2 rises and pH falls. Acute compensation is approximately +1 mEq/L HCO3− for each 10-mmHg PaCO2 rise above
40.
Chronic respiratory acidosis
Renal compensation is larger: approximately +3.5–4 mEq/L HCO3− per 10-mmHg PaCO2 rise. Chronic COPD with CO2
retention is the classic pattern.
Acute respiratory alkalosis
PaCO2 falls and pH rises; HCO3− falls only modestly. Think hyperventilation from pain, anxiety, hypoxemia, fever,
pregnancy, or early systemic illness.
Metabolic acidosis
HCO3− is low. Use Winter's formula: expected PaCO2 ≈ 1.5 × HCO3− + 8 ± 2. A measured PaCO2 outside the expected
range suggests a second respiratory disorder.
Metabolic alkalosis
HCO3− is high. A common bedside estimate for expected PaCO2 is about 0.7 × HCO3− + 20 ± 5. Excessive deviation
suggests an additional respiratory process.
Anion gap
AG = Na − (Cl + HCO3−). An elevated gap suggests accumulation of unmeasured anions. Interpret with albumin and the
clinical context.
Exam trap
Do not label compensation as a second primary disorder merely because PaCO2 or HCO3− moved in the expected
direction. Compensation is supposed to move in the opposite direction from the primary abnormality.
5. Oxygenation, A–a Gradient & P/F Ratio
P/F ratio
P/F = PaO2 / FiO2, with FiO2 written as a decimal. Example: PaO2 58 on FiO2 0.60 gives approximately 97.
A–a gradient
The alveolar–arterial oxygen gradient helps distinguish hypoxemia due to hypoventilation or low inspired oxygen from
impaired gas exchange such as V/Q mismatch, diffusion limitation, or shunt.
Oxygen delivery
DO2 depends on cardiac output and arterial oxygen content. Hemoglobin concentration and saturation matter; increasing
PaO2 above normal does not linearly increase oxygen content because dissolved oxygen contributes only a small fraction.
ARDS reasoning
In acute hypoxemic respiratory failure, consider P/F ratio, PEEP, chest imaging, timing, and noncardiogenic pulmonary
edema criteria. Avoid diagnosing severity from the P/F number alone without the required clinical context.
NBRC TMC / CRT / RRT 2026–2027 Enhanced Study Guide — Original educational material Page 3
