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RT (CRT/RRT) study materials
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RT (CRT/RRT) practice questions

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Question 1Patient Data

When preparing to draw an arterial blood gas sample, which pair of identifiers is acceptable for verifying the patient?

  1. Insurance provider and medical record number
  2. Room number and bed position
  3. Diagnosis and ordering physician
  4. Full name and date of birth Correct answer.

Explanation

Patient verification requires two independent identifiers, such as full name and date of birth or full name and medical record number. Room and bed assignments can change and do not uniquely identify a person.

Question 2Patient Data

What respiratory rate range is generally considered normal for a resting adult?

  1. 6 to 10 breaths/min
  2. 30 to 36 breaths/min
  3. 22 to 28 breaths/min
  4. 12 to 20 breaths/min Correct answer.

Explanation

A resting adult respiratory rate is normally about 12 to 20 breaths/min. Rates below this range suggest bradypnea, while rates above it suggest tachypnea.

Question 3Patient Data

A pulse oximeter reading of 97% on room air for a healthy adult is best interpreted as:

  1. Mild hypoxemia
  2. Hyperoxia requiring oxygen reduction
  3. Severe hypoxemia
  4. Within the normal range Correct answer.

Explanation

Pulse oximetry values around 94% to 100% on room air are generally normal for a healthy adult. Lower values may indicate hypoxemia and require clinical correlation.

Question 4Patient Data

Which information should be documented when a patient reports an allergy to a medication?

  1. Only the patient's statement that an allergy exists
  2. The medication, reaction, and severity Correct answer.
  3. Only the date the medication was last given
  4. The prescribing physician's name only

Explanation

A complete allergy entry identifies the medication and describes the reaction and its severity. This helps clinicians avoid the agent and choose safe alternatives.

Question 5Patient Data

Which resting heart rate is within the normal adult range?

  1. 42 beats/min
  2. 118 beats/min
  3. 78 beats/min Correct answer.
  4. 136 beats/min

Explanation

The normal resting adult heart rate is generally 60 to 100 beats/min. Values below 60 suggest bradycardia, and values above 100 suggest tachycardia.

Question 6Patient Data

Which oral temperature is most consistent with a normal adult value?

  1. 34.0°C (93.2°F)
  2. 39.5°C (103.1°F)
  3. 41.0°C (105.8°F)
  4. 37.0°C (98.6°F) Correct answer.

Explanation

Normal oral temperature is approximately 36.5°C to 37.5°C (97.7°F to 99.5°F). A value of 37.0°C (98.6°F) falls within this range.

Question 7Patient Data

When a sputum culture is ordered, which action best improves the usefulness of the specimen?

  1. Store the specimen at room temperature overnight
  2. Delay collection until after antibiotics are started
  3. Collect deep sputum before antibiotics Correct answer.
  4. Collect saliva after a meal

Explanation

A deep expectorated sputum specimen is more likely to represent lower respiratory secretions than saliva. Collecting it before antibiotics improves the chance of recovering the causative organism.

Question 8Patient Data

Who is responsible for obtaining informed consent for a procedure?

  1. Any available hospital volunteer
  2. The respiratory therapist assigned to the procedure
  3. The patient's insurance case manager
  4. The practitioner performing the procedure Correct answer.

Explanation

Informed consent is obtained by the practitioner who will perform the procedure, after discussing its risks, benefits, and alternatives. Other staff may witness or verify documentation but do not replace that responsibility.

Question 9Patient Data

A patient has smoked one pack per day for 20 years. What is the smoking history in pack-years?

  1. 40 pack-years
  2. 200 pack-years
  3. 10 pack-years
  4. 20 pack-years Correct answer.

Explanation

Pack-years are calculated by multiplying packs smoked per day by the number of years smoked. One pack per day for 20 years equals 20 pack-years.

Question 10Patient Data

An ABG shows pH 7.28, PaCO2 55 mm Hg, and HCO3- 24 mEq/L. Which interpretation is most accurate?

  1. Respiratory alkalosis without metabolic compensation
  2. Metabolic alkalosis with respiratory compensation
  3. Acute respiratory acidosis without compensation Correct answer.
  4. Metabolic acidosis with respiratory compensation

Explanation

The low pH indicates acidemia, and the elevated PaCO2 identifies a respiratory cause. A normal HCO3- of 24 mEq/L shows that metabolic compensation has not yet developed, consistent with acute respiratory acidosis.

Question 11Patient Data

Which spirometry pattern is most characteristic of obstructive lung disease?

  1. Reduced FEV1/FVC ratio with a reduced FEV1 Correct answer.
  2. Increased FVC with a normal FEV1/FVC ratio
  3. Increased FEV1/FVC ratio with reduced total lung capacity
  4. Normal FEV1/FVC ratio with reduced diffusing capacity only

Explanation

Obstructive disease slows expiratory airflow, so FEV1 falls and the FEV1/FVC ratio is reduced. Total lung capacity is often increased rather than reduced.

Question 12Patient Data

Which laboratory finding is most consistent with anemia?

  1. Platelet count 350,000/mm3
  2. Hemoglobin 9 g/dL Correct answer.
  3. Hematocrit 55%
  4. Hemoglobin 18 g/dL

Explanation

Anemia is defined by a reduction in hemoglobin concentration or hematocrit. A hemoglobin of 9 g/dL is below the usual adult reference range and supports anemia.

Question 13Patient Data

A patient's personal best peak expiratory flow is 500 L/min. A current reading of 300 L/min is what percentage of personal best?

  1. 167%
  2. 80%
  3. 40%
  4. 60% Correct answer.

Explanation

Peak flow as a percentage of personal best is calculated as current reading divided by personal best, multiplied by 100. 300 ÷ 500 × 100 equals 60%.

Question 14Patient Data

An ECG shows a regular rhythm with four large boxes between R waves. What is the approximate heart rate?

  1. 50 beats/min
  2. 60 beats/min
  3. 75 beats/min Correct answer.
  4. 100 beats/min

Explanation

For a regular rhythm, heart rate can be estimated by dividing 300 by the number of large boxes between R waves. 300 ÷ 4 equals 75 beats/min.

Question 15Patient Data

Which central venous pressure reading is within the usual normal adult range?

  1. 18 mm Hg
  2. −2 mm Hg
  3. 1 mm Hg
  4. 6 mm Hg Correct answer.

Explanation

Central venous pressure in a normal adult is commonly about 2 to 8 mm Hg. A reading of 6 mm Hg falls within that range.

Question 16Patient Data

A patient with severe anemia may have a normal pulse oximetry reading because oximetry primarily measures:

  1. Arterial oxygen tension directly
  2. Total oxygen content of the blood
  3. Hemoglobin oxygen saturation Correct answer.
  4. Dissolved oxygen in plasma

Explanation

Pulse oximetry estimates the percentage of hemoglobin binding sites saturated with oxygen. It does not measure hemoglobin concentration, so oxygen content can be low even when saturation appears normal.

Question 17Patient Data

A normal time-based capnogram in a spontaneously breathing patient most commonly has which appearance?

  1. A steady flat line
  2. Random irregular spikes
  3. A rectangular waveform Correct answer.
  4. A continuous sine wave

Explanation

A normal capnogram has a rapid inspiratory upstroke, an alveolar plateau, and a rapid inspiratory downstroke, producing a roughly rectangular shape. The plateau reflects alveolar gas.

Question 18Patient Data

When a respiratory therapist must add a late entry to a patient's medical record, the entry should include:

  1. The patient's verbal approval of the change
  2. Only the therapist's initials and no date
  3. A statement that the record was altered
  4. Original and late-entry dates and times Correct answer.

Explanation

A late entry should be clearly labeled and include the date and time of the original event as well as the date and time the entry is made. This preserves an accurate legal record.

Question 19Patient Data

An elevated B-type natriuretic peptide (BNP) is most consistent with:

  1. Bacterial meningitis
  2. Acute kidney stone
  3. Heart failure Correct answer.
  4. Severe anemia

Explanation

BNP is released when ventricular myocardium is stretched, as in heart failure. Elevated values support ventricular volume or pressure overload but must be interpreted with the clinical picture.

Question 20Patient Data

Which pulmonary function finding is most consistent with a restrictive lung pattern?

  1. Normal total lung capacity with reduced diffusing capacity
  2. Reduced total lung capacity with a normal ratio Correct answer.
  3. Increased residual volume with air trapping
  4. Reduced FEV1/FVC ratio with hyperinflation

Explanation

Restrictive disease reduces lung volumes, especially total lung capacity. The FEV1/FVC ratio is usually normal or increased because airflow is not the primary limitation.

Question 21Patient Data

An ABG shows pH 7.50, PaCO2 46 mm Hg, and HCO3- 34 mEq/L. Which acid-base disturbance is present?

  1. Metabolic alkalosis with respiratory compensation Correct answer.
  2. Metabolic acidosis with respiratory compensation
  3. Respiratory acidosis with metabolic compensation
  4. Respiratory alkalosis with metabolic compensation

Explanation

The elevated pH indicates alkalemia, and the elevated HCO3- identifies a metabolic alkalosis. The elevated PaCO2 reflects compensatory hypoventilation.

Question 22Patient Data

After bronchodilator therapy, an adult's FEV1 increases by 15% and 250 mL from baseline. This response is best described as:

  1. A fixed restrictive defect
  2. Significant bronchodilator response Correct answer.
  3. Normal diurnal variation only
  4. No meaningful bronchodilator response

Explanation

A significant bronchodilator response is generally defined as an increase in FEV1 of at least 12% and at least 200 mL from baseline. This patient meets both criteria.

Question 23Patient Data

A pulmonary artery occlusion (wedge) pressure of 20 mm Hg in an adult most likely indicates:

  1. Normal left ventricular filling pressure
  2. Pulmonary artery hypertension alone
  3. Elevated left heart filling pressure Correct answer.
  4. Hypovolemia

Explanation

A pulmonary artery occlusion pressure estimates left atrial pressure and left ventricular filling. Normal is roughly 6 to 12 mm Hg, so 20 mm Hg suggests elevated left heart filling pressures.

Question 24Patient Data

An ECG shows an irregularly irregular rhythm with no distinct P waves and a ventricular rate of 130 beats/min. This is most consistent with:

  1. Ventricular fibrillation
  2. Sinus tachycardia
  3. First-degree heart block
  4. Atrial fibrillation Correct answer.

Explanation

An irregularly irregular rhythm without distinct P waves is characteristic of atrial fibrillation. A ventricular rate of 130 beats/min indicates a rapid ventricular response.

Question 25Patient Data

Which calculation best estimates arterial oxygen content (CaO2)?

  1. (SaO2 ÷ PaO2) × 0.003 × hemoglobin
  2. (PaO2 × FiO2) + (0.003 × hemoglobin concentration)
  3. (1.34 × Hb × SaO2) + (0.003 × PaO2) Correct answer.
  4. (Hemoglobin × PaCO2) ÷ 1.34 + 0.003

Explanation

Arterial oxygen content is estimated from oxygen bound to hemoglobin plus dissolved oxygen. The bound portion uses 1.34 mL O2 per gram of hemoglobin times hemoglobin concentration times arterial saturation, and dissolved oxygen is about 0.003 times PaO2.

Question 26Patient Data

Which respiratory rate range is considered normal for a resting adult?

  1. 22 to 28 breaths/min
  2. 4 to 8 breaths/min
  3. 12 to 20 breaths/min Correct answer.
  4. 30 to 40 breaths/min

Explanation

A normal resting respiratory rate for an adult is 12 to 20 breaths/min. Rates below 12 are termed bradypnea, and rates above 20 are termed tachypnea.

Question 27Patient Data

Before drawing an arterial blood gas, which practice best confirms the correct patient?

  1. Ask the nurse which bed is assigned
  2. Read the name on the specimen label
  3. Confirm name and date of birth Correct answer.
  4. Check the room number on the door

Explanation

At least two identifiers, such as full name and date of birth, must be verified before any procedure or specimen collection. Room numbers, bed assignments, and labels can be incorrect and are not acceptable patient identifiers.

Question 28Patient Data

Which description best characterizes a wheeze?

  1. Harsh low-pitched sound over the trachea
  2. Grinding sound over the pleura in both phases
  3. Continuous, high-pitched expiratory sound Correct answer.
  4. Brief popping sound heard on inspiration

Explanation

Wheezes are continuous, high-pitched musical sounds produced by narrowed airways and are heard mainly on expiration. Crackles are brief and discontinuous, harsh tracheal sounds are normal over the large airways, and a grating sound suggests a pleural rub.

Question 29Patient Data

Which document lets a patient state treatment preferences in advance in case they lose decision-making capacity?

  1. An advance directive Correct answer.
  2. A consultation report
  3. A discharge summary
  4. A progress note

Explanation

An advance directive is a legal document that records a patient's wishes for future medical care if they become unable to make decisions. Discharge summaries, consultation reports, and progress notes record care that has already been provided.

Question 30Patient Data

A respiratory therapist writes an incorrect value in a paper medical record. What is the correct way to fix the error?

  1. Cover it with correction fluid and rewrite
  2. Single-line it, then initial and date Correct answer.
  3. Erase the entry and rewrite the correct value
  4. Remove the page and rewrite the whole record

Explanation

The accepted correction is to draw a single line through the error so the original entry remains legible, then add initials and the date, often with the word "error." Erasing, using correction fluid, or removing pages alters the legal record.

Question 31Patient Data

A capnogram shows a gradually sloping upstroke that takes on a shark-fin shape. Which condition does this most suggest?

  1. Airflow obstruction, such as asthma Correct answer.
  2. Cardiac arrest with no perfusion
  3. A normal spontaneously breathing adult
  4. A leak around the endotracheal tube

Explanation

A sloping, shark-fin-shaped upstroke reflects uneven alveolar emptying caused by airflow obstruction. A normal capnogram has a steep, nearly vertical upstroke followed by a flat plateau.

Question 32Patient Data

An ECG rhythm strip shows a regular rate of 48 beats/min with an upright P wave before every QRS complex. Which interpretation is correct?

  1. Ventricular tachycardia
  2. Sinus tachycardia
  3. Sinus bradycardia Correct answer.
  4. Atrial fibrillation

Explanation

A regular rhythm slower than 60 beats/min with a P wave before every QRS complex is sinus bradycardia. The consistent P waves confirm that the rhythm originates in the sinus node.

Question 33Patient Data

A patient has a heart rate of 80 beats/min and a stroke volume of 70 mL. What is the cardiac output?

  1. 0.56 L/min
  2. 5.6 L/min Correct answer.
  3. 8.0 L/min
  4. 1.1 L/min

Explanation

Cardiac output equals heart rate multiplied by stroke volume: 80 beats/min × 70 mL = 5600 mL/min, or 5.6 L/min.

Question 34Patient Data

A patient has cold, mottled fingers and poor peripheral perfusion. How does this most affect pulse oximetry?

  1. It will read falsely high from vasoconstriction
  2. It is unaffected because it samples venous blood
  3. It may read falsely low from a poor signal Correct answer.
  4. It will remain accurate if the probe is on a finger

Explanation

Poor perfusion and cold extremities reduce signal quality and can make pulse oximetry read falsely low or fail to give a reading. Oximetry relies on pulsatile arterial blood, not venous blood.

Question 35Patient Data

A chest radiograph shows a region with no visible vascular markings beyond a clear lung edge. Which finding does this describe?

  1. Pneumothorax Correct answer.
  2. Atelectasis
  3. Pulmonary edema
  4. Pleural effusion

Explanation

A pneumothorax appears as an area without lung markings beyond a visible pleural line. Pleural effusion and atelectasis produce opacity, and pulmonary edema causes bilateral infiltrates.

Question 36Patient Data

An ABG shows pH 7.30, PaCO2 40 mm Hg, and HCO3- 19 mEq/L. Which interpretation is most accurate?

  1. Uncompensated respiratory acidosis
  2. Compensated metabolic alkalosis
  3. Respiratory alkalosis with compensation
  4. Uncompensated metabolic acidosis Correct answer.

Explanation

A low pH with a low bicarbonate and a PaCO2 that has not fallen indicates a primary metabolic acidosis without respiratory compensation. In respiratory acidosis the PaCO2 would be elevated.

Question 37Patient Data

A patient's peak expiratory flow varies by 25% between morning and evening readings over a week. What does this most suggest?

  1. Poorly controlled asthma Correct answer.
  2. A restrictive lung disease
  3. Improving airway obstruction
  4. Normal diurnal variation

Explanation

Diurnal peak flow variability greater than 20% suggests variable airflow obstruction, as seen in poorly controlled asthma. Normal variation is generally less than 20%.

Question 38Patient Data

An ABG shows Na+ 140 mEq/L, Cl- 105 mEq/L, and HCO3- 18 mEq/L. What is the anion gap?

  1. 12 mEq/L
  2. 22 mEq/L
  3. 17 mEq/L Correct answer.
  4. 35 mEq/L

Explanation

Anion gap = Na+ − (Cl− + HCO3−) = 140 − (105 + 18) = 17 mEq/L. A value above about 12 mEq/L suggests a high-anion-gap metabolic acidosis.

Question 39Patient Data

A patient with diabetic ketoacidosis has an HCO3- of 12 mEq/L and a PaCO2 of 30 mm Hg. Using Winter's formula, which statement best describes the respiratory compensation?

  1. Excessive, producing a superimposed respiratory alkalosis
  2. Absent, because the PaCO2 has not changed
  3. Inadequate; a respiratory acidosis is also present Correct answer.
  4. Appropriate for the degree of metabolic acidosis

Explanation

Winter's formula predicts PaCO2 = 1.5 × HCO3− + 8 ± 2, which here is 24 to 28 mm Hg. The actual PaCO2 of 30 mm Hg is above that range, so respiratory compensation is inadequate and a respiratory acidosis coexists.

Question 40Patient Data

Which condition typically produces a reduced diffusing capacity for carbon monoxide (DLCO)?

  1. Emphysema Correct answer.
  2. Obesity
  3. Pulmonary hemorrhage
  4. Asthma

Explanation

DLCO measures gas transfer across the alveolar-capillary membrane and is typically reduced in emphysema because of loss of alveolar surface area. Asthma usually gives normal or increased values, obesity is usually normal, and pulmonary hemorrhage can increase DLCO.

Question 41Oxygen Supply and Therapy

A respiratory therapist is preparing to attach a regulator to a full oxygen cylinder. Which action is appropriate?

  1. Keep oil and grease away from the valve and regulator Correct answer.
  2. Lubricate the yoke threads with petroleum jelly to ease attachment
  3. Check for leaks by holding an open flame near the valve
  4. Lay the cylinder horizontally on the floor for storage

Explanation

Oxygen under pressure is a powerful oxidizer, and hydrocarbon residues such as oil, grease, or petroleum jelly can ignite violently in an oxygen-enriched environment. Cylinders should also be secured upright rather than laid flat, and leaks should be checked with soap solution or a commercial leak detector, never a flame.

Question 42Oxygen Supply and Therapy

Which oxygen flow range is appropriate for a standard adult nasal cannula?

  1. 0.1 to 0.5 L/min
  2. 8 to 12 L/min
  3. 12 to 15 L/min
  4. 1 to 6 L/min Correct answer.

Explanation

A nasal cannula is a low-flow device run at 1 to 6 L/min, which yields an FiO2 of roughly 0.24 to 0.44 depending on the patient's inspiratory flow and tidal volume. The device does not seal the airway, so flows above 6 L/min dry the nasal mucosa without reliably raising the inspired oxygen concentration.

Question 43Oxygen Supply and Therapy

What is the minimum oxygen flow that should be set on a simple face mask?

  1. 5 L/min Correct answer.
  2. 10 L/min
  3. 3 L/min
  4. 1 L/min

Explanation

A simple mask must receive at least 5 L/min so exhaled carbon dioxide is flushed out through the exhalation ports instead of being rebreathed. The usual operating range is 5 to 10 L/min, producing an FiO2 of about 0.35 to 0.50.

Question 44Oxygen Supply and Therapy

A non-rebreather mask with a reservoir bag is running at 12 L/min for a spontaneously breathing adult. Which FiO2 range does this device typically provide?

  1. 0.40 to 0.50
  2. 0.60 to 0.80 Correct answer.
  3. 0.24 to 0.28
  4. 0.35 to 0.40

Explanation

When the reservoir bag is kept inflated and the mask seals reasonably well, a non-rebreather delivers roughly 0.60 to 0.80 FiO2 at 10 to 15 L/min, and the one-way valves prevent rebreathing of exhaled gas. It is the highest-FiO2 device among the standard low-flow systems.

Question 45Oxygen Supply and Therapy

An E cylinder gauge reads 1200 psi, and the prescribed flow is 4 L/min. Using a cylinder factor of 0.28 L/psi, how long will the cylinder last?

  1. 84 minutes Correct answer.
  2. 168 minutes
  3. 34 minutes
  4. 42 minutes

Explanation

Cylinder duration equals gauge pressure times the cylinder factor divided by flow: (1200 psi x 0.28 L/psi) / 4 L/min = 84 minutes. Some clinicians subtract a small residual pressure before calculating so the patient is not left with an empty cylinder.

Question 46Oxygen Supply and Therapy

Which SpO2 range is the appropriate target for a COPD patient with chronic CO2 retention who requires oxygen?

  1. 98% to 100%
  2. 88% to 92% Correct answer.
  3. 94% to 98%
  4. 80% to 85%

Explanation

In patients with chronic hypercapnia whose hypoxic drive sustains ventilation, oxygen should be titrated to an SpO2 of about 88% to 92% to avoid worsening hypercarbia and respiratory acidosis. Oxygen is still given for hypoxemia; the goal is controlled titration rather than withholding therapy.

Question 47Oxygen Supply and Therapy

A Venturi (air-entrainment) mask is ordered for a patient with COPD. Which characteristic is the main advantage of this device?

  1. It requires no humidification at any flow rate
  2. It provides a stable FiO2 despite variable breathing Correct answer.
  3. It delivers a higher FiO2 than any other low-flow device
  4. It eliminates the need for a flowmeter and tubing

Explanation

Air entrainment creates a total gas flow that exceeds the patient's peak inspiratory demand, so the FiO2 remains fixed at the set value regardless of respiratory rate or tidal volume. This predictability is why the Venturi mask is preferred when a precise, relatively low FiO2 must be maintained.

Question 48Oxygen Supply and Therapy

According to AARC guidance, humidification should be added to a nasal cannula when oxygen flow exceeds which rate?

  1. 10 L/min
  2. 2 L/min
  3. 1 L/min
  4. 4 L/min Correct answer.

Explanation

Above about 4 L/min the volume of dry gas exceeds what the upper airway can humidify, leading to mucosal drying, crusting, and thickened secretions. Devices that bypass the upper airway, such as artificial airways, always require humidification regardless of flow.

Question 49Oxygen Supply and Therapy

A therapist is mounting a small oxygen cylinder onto a yoke. The pin-index safety system exists to:

  1. Prevent attaching a cylinder of a different gas Correct answer.
  2. Prevent overfilling of the cylinder
  3. Release excess pressure if the cylinder overheats
  4. Measure the remaining gas volume in the cylinder

Explanation

Each medical gas has a unique arrangement of two pins that matches holes in the cylinder valve, so only the correct cylinder fits a given yoke. Large cylinders rely on the differently threaded outlets of the American Standard Safety System, and overpressure is handled by a separate relief device.

Question 50Oxygen Supply and Therapy

Which statement about the flammability of oxygen is accurate?

  1. Oxygen is inert and cannot support burning
  2. Oxygen is a flammable gas that ignites on contact with air
  3. It is nonflammable but speeds burning of other materials Correct answer.
  4. Oxygen extinguishes sparks because it is cooler than air

Explanation

Oxygen itself does not burn, but it is a powerful oxidizer that lowers the ignition temperature and increases the burning rate of fuels. That is why an oxygen-enriched atmosphere makes ordinary materials such as clothing, grease, and hair extremely hazardous.