Deck 10: Assessment of Respiratory Function

Question 1

While trying to use a finger probe to assess a patient's oxygenation status,the respiratory therapist finds that the pulse rate and the ECG monitor heart rate are not consistent and the oxygen saturation measured by pulse oximeter (S_pO₂)reading is blank.The patient is awake,alert,and in no obvious respiratory distress.The respiratory therapist should first take which of the following actions?
1)Change the probe site.
2)Draw an arterial blood gas.
3)Adjust the probe position on the finger.
4)Remove probe,perform a capillary refill test.

A) 1 and 2 only
B) 2 and 3 only
C) 3 and 4 only
D) 1 and 4 only

Answer 1

3 and 4 only

Question 2

The respiratory therapist has just stopped postural drainage for a 24-year-old patient with cystic fibrosis because of shortness of breath and slight cyanosis in the "head-down" position.The respiratory therapist should recommend which of the following adjustments to therapy?

A) Continue postural drainage and monitor patient with capnography.
B) Use only upright or flat postural drainage positions and draw an arterial blood gas (ABG).
C) Administer oxygen via nasal cannula and monitor with pulse oximetry.
D) Use a transcutaneous partial pressure of oxygen (PO₂)monitor to assess the extent of hypoxemia.

Answer 2

Administer oxygen via nasal cannula and monitor with pulse oximetry.

Question 3

The area represented by the letter "Y" in the figure is which of the following?

A) End-tidal carbon dioxide (EtCO₂)
B) Alveolar ventilation
C) Alveolar dead space
D) Airway dead space

Answer 3

Alveolar dead space

Question 4

During which phase of a capnograph does alveolar gas containing carbon dioxide (CO₂)mix with gas from the anatomical airways and the CO₂ concentration rises?

A) Phase 1
B) Phase 2
C) Phase 3
D) Phase 4

Question 5

Which of the following situations will cause an increase in the single breath carbon dioxide (CO₂)curve?

A) Decreased metabolic rate and decreased ventilation
B) Decreased metabolic rate and increased ventilation
C) Increased metabolic rate and increased ventilation
D) Increased metabolic rate and decreased ventilation

Question 6

For a given minute ventilation,partial pressure of end-tidal carbon dioxide (PetCO₂)is a function of which of the following?
1)Metabolic rate
2)Cardiac output
3)Alveolar deadspace
4)Physiologic shunt

A) 1 and 3 only
B) 1,2,and 3 only
C) 2,3 and 4 only
D) 1,2,3,and 4

Question 7

The partial pressure of end-tidal carbon dioxide (PetCO₂) reading is taken at what point in the figure?

A) Point A
B) Point B
C) Point C
D) Point D

Question 8

The normal range for arterial-to-end-tidal partial pressure of carbon dioxide [P(a-et)CO₂] is which of the following?

A) 2 to 4 mm Hg
B) 4 to 6 mm Hg
C) 6 to 8 mm Hg
D) 8 to 10 mm Hg

Question 9

A patient receiving mechanical ventilation is being continuously monitored for oxygen saturation measured by pulse oximeter (S_pO₂)for the last 48 hours.When initially applied,the S_pO₂ and the arterial oxygen saturation (S_aO₂),as well as the pulse on the pulse oximeter,ECG,and manual pulse,were consistent.During clinical rounds,the respiratory therapist notices that although the probe is appropriately placed and capillary refill is normal,the S_pO₂ reading is down to 90% from 95%.The most appropriate immediate action is to do which of the following?

A) Replace the probe.
B) Reposition the patient.
C) Draw an arterial blood gas.
D) Move the probe to a different site.

Question 10

A patient arrives in the emergency department via ambulance following rescue from a house fire.The instrument that would be most appropriate to assist the respiratory therapist in assessing this patient's oxygenation status is which of the following?

A) Capnograph
B) Pulse oximeter
C) Calorimeter
D) CO-Oximeter

Question 11

A pulse oximeter differentiates oxyhemoglobin from deoxygenated hemoglobin by which of the following methods?

A) Relating cyclical changes in light transmission through the sampling site
B) Shining and comparing two wavelengths of light through the sampling site
C) Direct measurement by a heated polarographic electrode applied to the skin
D) Using a color sensing device that absorbs one wavelength of light through the skin

Question 12

Pulse oximetry is most useful in which of the following situations?

A) Determining when to extubate an adult
B) Prescribing oxygen therapy for neonates
C) Monitoring patients undergoing chest physical therapy
D) Establishing initial oxygen necessity for home care patients

Question 13

A patient in the intensive care unit is receiving mechanical ventilation,has a pulmonary artery catheter in place,and is being monitored continuously with a capnometer.The patient's arterial partial pressure of carbon dioxide (P_aCO₂)is 41 mm Hg and the partial pressure of end-tidal carbon dioxide (PetCO₂)is 36 mm Hg.There is a sudden decrease in the PetCO₂ to 18 mm Hg causing an alarm to sound.The most likely cause of this development is which of the following?

A) Hypovolemia
B) Apneic episode
C) Pulmonary embolism
D) Increased cardiac output

Question 14

A pulse oximeter reading will be most accurate when used with a patient in which of the following situations?

A) An intensive care unit patient with hyperbilirubinemia
B) A hypotensive patient receiving peripheral vasoconstrictors
C) An emergency department patient with evidence of smoke inhalation
D) An open heart patient receiving extracorporeal membrane oxygenation

Question 15

An arterial blood gas should be done to confirm pulse oximetry findings less than a minimum of _____________.

A) 60%
B) 70%
C) 80%
D) 90%

Question 16

During shift report,the day shift respiratory therapist informs the night shift respiratory therapist about a freshly postoperative patient who is receiving full support via mechanical ventilation.At the time of the last patient-ventilator system check the patient had not awaken from anesthesia.During first rounds on the day shift the respiratory therapist notes the capnography shown in the figure.The most appropriate action to take would be to do which of the following?

A) Administer a bronchodilator.
B) Begin the weaning process.
C) Fix the leak in the sampling line.
D) Reinflate the ET tube cuff.

Question 17

The change in the single breath carbon dioxide (CO₂) curve from "A" to "B" shown in the figure may be as a result of which of the following?

A) Hypervolemia
B) Decreased positive-end-expiratory pressure (PEEP)
C) Increased mean airway pressure
D) Excessive bronchodilator administration

Question 18

The capnogram in the figure is indicative of which of the following conditions?

A) Chronic obstructive pulmonary disease (COPD)
B) Cardiac arrest
C) Hyperventilation
D) Pulmonary embolism

Question 19

During which phase of a capnogram does inhalation occur?

A) Phase 1
B) Phase 2
C) Phase 3
D) Phase 4

Question 20

The area under the curve of a single breath carbon dioxide curve (SBCO₂)represents which of the following?

A) Tidal volume
B) Alveolar dead space
C) Physiologic dead space
D) Effective alveolar ventilation

Question 21

Components of an indirect calorimeter may include which of the following?
1)Pressure manometer
2)Pneumotachometer
3)Pressure-sensitive transducer
4)Oxygen and carbon dioxide analyzers

A) 1 and 2 only
B) 2 and 4 only
C) 2,3,and 4 only
D) 1,2,3,and 4

Question 22

During calibration of a transcutaneous monitor the respiratory therapist notices a signal drift.The respiratory therapist should do which of the following?

A) Increase the probe temperature.
B) Replace the monitor and call for repair.
C) Add more electrolyte gel to the patient's skin.
D) Change the electrolyte and sensor's membrane.

Question 23

The clinical data that should be recorded when making transcutaneous measurements include which of the following?
1)Electrode temperature
2)Skin temperature
3)Probe placement
4)Fractional Inspired Oxygen (FiO₂)

A) 1 and 3 only
B) 1 and 2 only
C) 2,3,and 4 only
D) 1,2,3 and 4

Question 24

What type of electrode is used by a transcutaneous partial pressure of carbon dioxide (PtcCO₂)device?

A) Galvanic
B) Polarographic
C) Paramagnetic
D) Stow-Severinghaus

Question 25

To properly operate,the transcutaneous partial pressure of oxygen electrode needs to be at what temperature range?

A) 32° C to 35° C
B) 36° C to 39° C
C) 42° C to 45° C
D) 46° C to 49° C

Question 26

An energy expenditure (EE)of 20 kcal/hr/m² for an adult is indicative of which of the following conditions?

A) Pregnancy
B) Starvation
C) Hyperthyroidism
D) Stimulant drugs

Question 27

The condition that is associated with a reduction in exhaled nitric oxide is which of the following?

A) Alveolitis
B) Cystic fibrosis
C) Chronic bronchitis
D) Airway viral infection

Question 28

The respiratory quotient (RQ)value associated with substrate utilization patterns in normal,healthy individuals is which of the following?

A) 0.7
B) 0.8
C) 0.9
D) 1.0

Question 29

Exhaled nitric oxide is used to monitor the effectiveness of which drug used in the treatment of asthma?

A) Anticholinergic bronchodilators
B) Beta adrenergic bronchodilators
C) Corticosteroids
D) Leukotriene inhibitors

Question 30

A patient is receiving mechanical ventilation with a fractional inspired oxygen (F_IO₂)of 0.85 and a positive-end-expiratory pressure (PEEP)of 5 cm H₂O.His arterial partial pressure of oxygen (P_aO₂)is 68 mm Hg,arterial oxygen saturation (S_aO₂)is 88%,and partial pressure of end-tidal carbon dioxide (PetCO₂) is 32 mm Hg.Over the next few minutes his PEEP is titrated resulting in the following data: At 0740 the single breath carbon dioxide curve (SBCO₂)curve shifted to the right.What action should the respiratory therapist take at this time?

A) Increase the F_IO₂ to 0.90.
B) Reduce the set tidal volume.
C) Continue to increase the PEEP.
D) Reduce the PEEP to 12 cm H₂O.

Question 31

A patient whose carbon dioxide (CO₂)production is 390 mL/min and oxygen (O₂)consumption is 375 mL/min is most likely experiencing which of the following?

A) Ketosis
B) Severe sepsis
C) Hyperventilation
D) Too much carbohydrate intake

Question 32

Select the ventilator flowmeter that will read accurately when used with heliox.

A) Turbine
B) Vortex ultrasonic
C) Variable capacitance
D) Variable orifice pneumotachometer

Question 33

A strain gauge transducer is being used to measure airway pressures during mechanical ventilation.The transducer measures 18 mm Hg.However,you are required to document pressures in cm H₂O.What should you document?

A) 39.6 cm H₂O
B) 24.5 cm H₂O
C) 13.2 cm H₂O
D) 2.4 cm H₂O

Question 34

An energy expenditure (EE)of 60 kcal/hr/m² for an adult is indicative of which of the following conditions?

A) Burns
B) Sedation
C) Starvation
D) Hypothermia

Question 35

A transcutaneous partial pressure of oxygen (PtcO₂)reading is inaccurate in all of the following situations EXCEPT:

A) Hypothermia
B) Septic Shock
C) Infant Respiratory Distress Syndrome
D) Elevated peripheral (cutaneous)resistance

Question 36

To measure plateau pressure,inspiration should be held for how many seconds?

A) 1 - 2
B) 2 - 3
C) 3 - 4
D) 4 - 5

Question 37

A mechanically ventilated patient with chronic obstructive pulmonary disease is in the process of being weaned from mechanical ventilation.A diet containing which of the following will be most beneficial to this process?

A) High protein,low fats and carbohydrates
B) Low fats and proteins,high carbohydrates
C) Low carbohydrate with increased fats and proteins
D) Equal amounts of carbohydrates,fats,and proteins

Question 38

The newest types of mechanical ventilators use which of the following devices to measure airway pressures?

A) Barometers
B) Aneroid manometers
C) Electromechanical transducers
D) Variable orifice pneumotachometers

Question 39

What type of electrode is used by a transcutaneous partial pressure of oxygen (PtcO₂)device?

A) Galvanic
B) Polarographic
C) Paramagnetic
D) Stow-Severinghaus

Question 40

How often should the respiratory therapist reposition the sensor of a transcutaneous monitor?

A) 30 minutes to 1 hour
B) 1 to 3 hours
C) 4 to 6 hours
D) 7 to 9 hours

Question 41

The energy required to move gas through the airways and expand the thorax is known as which of the following?

A) Airway resistance
B) Dynamic compliance
C) Intrinsic work of breathing
D) Extrinsic work of breathing

Question 42

Calculate dynamic compliance given the following clinical data: tidal volume 600 mL,peak inspiratory pressure (PIP)28 cm H₂O,plateau pressure (P_plateau)15 cm H₂O,positive-end-expiratory pressure (PEEP)10 cm H₂O,C_T 2 mL/cm H₂O.

A) 30.2 mL/cm H₂O
B) 31.3 mL/cm H₂O
C) 38 mL/cm H₂O
D) 44.1 mL/cm H₂O

Question 43

Bidirectional flow can be measured by which of the following devices?

A) Turbine flowmeter
B) Piezoelectric transducer
C) Ultrasonic vortex flowmeter
D) Variable orifice pneumotachometer

Question 44

Calculate the airway resistance given the following clinical data: flow rate 60 L/min,PIP 28 cm H₂O,P_plateau 21 cm H₂O,PEEP 8 cm H₂O.

A) 7 cm H₂O/L/sec
B) 13 cm H₂O/L/sec
C) 20 cm H₂O/L/sec
D) 28 cm H₂O/L/sec

Question 45

At which point in the pressure-time curve of a spontaneous breath should the transdiaphragmatic pressure be greatest?

A) Mid-inspiration
B) Mid-expiration
C) End of exhalation
D) Beginning of inspiration

Question 46

During the application of positive-end-expiratory pressure (PEEP),the monitoring of which pressure will alert the respiratory therapist specifically to alveolar overdistention?

A) Peak inspiratory pressure (PIP)
B) Plateau pressure (P_plateau)
C) Mean airway pressure ()
D) Transairway pressure (P_TA)

Question 47

Calculate the static compliance given the following clinical data: tidal volume 600 mL,peak inspiratory pressure (PIP)40 cm H₂O,plateau pressure (P_plateau)30 cm H₂O,positive-end-expiratory pressure (PEEP)15 cm H₂O,tubing compliance (C_T)2 mL/cm H₂O.

A) 14.5 mL/cm H₂O
B) 38 mL/cm H₂O
C) 55 mL/cm H₂O
D) 58 mL/cm H₂O

Question 48

Calculate the static compliance given the following clinical data: tidal volume 500 mL,peak inspiratory pressure (PIP)35 cm H₂O,plateau pressure (P_plateau)25 cm H₂O,positive-end-expiratory pressure (PEEP)12 cm H₂O,measured unintended positive-end-expiratory pressure (auto-PEEP)3 cm H₂O,tubing compliance (C_T)2.5 mL/cm H₂O.

A) 17.5 mL/cm H₂O
B) 34 mL/cm H₂O
C) 36 mL/cm H₂O
D) 47.5 mL/cm H₂O

Question 49

An increase in intrinsic work of breathing due to a decrease in static compliance is caused by which of the following?

A) Emphysema
B) Bronchospasm
C) Pulmonary fibrosis
D) Airway inflammation

Question 50

A patient-ventilator system check reveals the following information: peak inspiratory pressure (PIP)32 cm H₂O,positive-end-expiratory pressure (PEEP)12 cm H₂O,plateau pressure (P_plateau)20 cm H₂O,inspiratory time (T_I)1 second,set frequency 12/minute.Calculate the mean airway pressure.

A) 4 cm H₂O
B) 8 cm H₂O
C) 12 cm H₂O
D) 14 cm H₂O

Question 51

The best assessment of the function of the diaphragm during inspiration is obtained by measuring which of the following?

A) Airway resistance
B) Pressure-time product
C) Pressure-volume curve
D) Maximum inspiratory pressure

Question 52

Calculate the dynamic compliance given the following clinical data: tidal volume 500 mL,peak inspiratory time (PIP)35 cm H₂O,plateau pressure (P_plateau)20 cm H₂O,positive-end-expiratory pressure (PEEP)5 cm H₂O,tubing compliance (C_T)2.5 mL/cm H₂O.

A) 11.8 mL/cm H₂O
B) 14.2 mL/cm H₂O
C) 25 mL/cm H₂O
D) 46.2 mL/cm H₂O

Question 53

A patient-ventilator system check reveals the following information: peak inspiratory pressure (PIP)27 cm H₂O,positive-end-expiratory pressure (PEEP)5 cm H₂O,plateau pressure (P_plateau)14 cm H₂O,inspiratory time (T_I)0.75 second,set frequency 20/minute.Calculate the mean airway pressure.

A) 6.75 cm H₂O
B) 7.75 cm H₂O
C) 11.75 cm H₂O
D) 12.37 cm H₂O

Question 54

Calculate the airway resistance given the following clinical data: flow rate 60 L/min,peak inspiratory pressure (PIP)42 cm H₂O,plateau pressure (P_plateau)15 cm H₂O,positive-end-expiratory pressure (PEEP)5 cm H₂O.

A) 10 cm H₂O/L/sec
B) 30 cm H₂O/L/sec
C) 37 cm H₂O/L/sec
D) 42 cm H₂O/L/sec