Deck 6: Humidity and Aerosol Therapy

Question 1

What is the relative humidity when the absolute humidity is 15 mg H₂O/L and the capacity of a gas is 20.6 mg H₂O/L?

A) 15%
B) 20%
C) 30%
D) 72%

Answer 1

D
RH = (AH/capacity)* 100%.(15 mg/L/20.6 mg/L)* 100% = 72%.

Question 2

Which of the following statements about the isothermic saturation boundary is true?

A) Exercise causes the isothermic saturation boundary to shift higher in the trachea.
B) At 2 cm above the carina, inhaled gas reaches BTPS.
C) Inhalation through the mouth shifts the isothermic saturation boundary downward.
D) Below the isothermic saturation boundary, temperature and relative humidity are variables.

Answer 2

C
At the isothermic saturation boundary inhaled gas reaches BTPS,which is below the carina.The temperature and relative humidity are constant after that point.Because exercise causes an increase in the volume,rate,and type of breathing (i.e.,breathing through the mouth),the isothermic saturation boundary would shift downward.

Question 3

Which of the following statements is true?

A) Water that exists in the form of individual molecules in a gaseous state is humidity.
B) Water that exists in the form of individual molecules is an aerosol.
C) Water that exists in the form of particulate matter is relative humidity (RH).
D) Water that exerts no pressure is a vapor.

Answer 3

A
Humidity is water that exists in the form of individual molecules in the vaporous or gaseous state.An aerosol is a suspension of solid or liquid particles in a gas.Water vapor does exert pressure,although the pressure may vary.

Question 4

A patient is receiving albuterol through a small-volume nebulizer.Where in the body will the greatest effect take place?

A) Localized effect in the lungs
B) Systemic effect
C) Local and systemic effect
D) Depends on the size, temperature, and volume of the aerosol

Question 5

Inspired air is humidified and warmed through what two physical processes?
1)Condensation
2)Evaporation
3)Convection
4)Conduction

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

Question 6

Which of the following statements is true?

A) Fog and mist are considered water vapor.
B) Medical aerosols are much smaller than molecules of water.
C) Medical aerosols range from 0.2 mm to 50 mm.
D) All of the above are true.

Question 7

Which of the following is true about the physiologic control of heat and moisture exchange by the body?

A) The nose, oropharynx, and hypopharynx add heat and humidity during exhalation.
B) The nose, oropharynx, and hypopharynx cool gas and reclaim water during inhalation.
C) The inability of the nasal mucosa to reabsorb excessive amounts of exhaled condensation in cold weather causes a "runny nose."
D) The mouth is more efficient at reclaiming heat and water during exhalation than is the nose.

Question 8

At 20° C,water vapor pressure is measured as 15 mm Hg.If the maximum partial pressure at this temperature is 17.5 mm Hg,the relative humidity is:

A) 30%.
B) 50%.
C) 75%.
D) 85%.

Question 9

The isothermic saturation boundary is located just below the:

A) carina.
B) nasopharynx.
C) lobar bronchi.
D) mainstem bronchi.

Question 10

A water molecule at the surface contains enough kinetic activity to enter the vapor state.This is the definition of which of the following?

A) Evaporation
B) Vaporization
C) The boiling point
D) The critical point

Question 11

A large humidity deficit will cause:

A) a nonproductive cough.
B) increased cilia function.
C) increased movement of mucus.
D) decreased airway resistance.

Question 12

A pulse oximeter on a patient with a tracheostomy shows 89% saturation.The patient has a heated humidifier with a 40% air-entrainment tracheostomy collar.A rapid assessment shows no secretion production and equal breath sounds.Which of the following is the most appropriate first step?

A) Increase the oxygen delivered through the flowmeter.
B) Increase the air-entrainment device to 60%.
C) Apply positive pressure with bag-valve ventilation.
D) Check to see whether water is collected in the gas-delivery tube.

Question 13

Condensation will form in large-bore corrugated tubing during the delivery of bland aerosol because the:

A) gas is warmed by ambient air.
B) corrugated tubing is too short.
C) gas is cooled by ambient air.
D) particles are susceptible to gravity.

Question 14

When absolute humidity (AH)is constant and the temperature of the gas increases,the:

A) gas is saturated.
B) capacity decreases.
C) water content increases.
D) relative humidity decreases.

Question 15

At 37° C,water vapor exerts a partial pressure of ____ mm Hg and contains _____ mg H₂O/L.

A) 43.9; 47
B) 47; 43.9
C) 44; 44
D) 100; 100

Question 16

Which of the following are true about the function of the upper airways?
1)They cool inspired air.
2)They filter out secretions.
3)They humidify inspired air.
4)They keep the nasal mucosa moist.

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

Question 17

The relative humidity is 40% and the capacity is 32 mg H₂O/L.The absolute humidity of this gas is _____ mm Hg.

A) 1.3
B) 12.8
C) 60
D) 128

Question 18

If its relative humidity is 50% and its absolute humidity is 16 mg H₂O/L,the water vapor capacity of a gas is _____ mg H₂O/L.

A) 0.8
B) 3.2
C) 8
D) 32

Question 19

The structure that has a large surface area and therefore increases contact between inspired air and mucosa is the:

A) nose.
B) carina.
C) larynx.
D) epiglottis.

Question 20

Which of the following is true concerning water vapor?

A) It is a true gas.
B) It has a constant pressure.
C) It exerts a partial pressure.
D) It exists above its critical temperature.

Question 21

A high-flow nasal cannula set at 15 L has been running for a while without water.Which of the following could have happened?

A) The cilia function increases.
B) Turbulent convection stops.
C) Airway resistance decreases.
D) The isothermic saturation boundary shifts.

Question 22

The actual water vapor pressure at 37° C when the relative humidity is 50% is _____ mm Hg.

A) 18.5
B) 23.5
C) 22
D) 45

Question 23

A patient reports a dry nose and throat.He is receiving 6 L of O₂ through a nasal cannula. Which of the following is most appropriate to address the patient's dry nose and throat?

A) Decrease the oxygen flow rate to 3 L.
B) Add a low-flow bubble humidifier.
C) Suggest an aerosol treatment with a mucolytic agent.
D) Take no action.

Question 24

Indications for the use of warm,humidified gas are which of the following?
1)Patients with hypothermia
2)Patients with croup
3)Patients with bronchospasm
4)Patients with postextubation edema

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

Question 25

What is the relative humidity of air at 37° C if the actual water vapor pressure is 33 mm Hg?

A) 89%
B) 75%
C) 70%
D) 25%

Question 26

If the relative humidity of a gas is 55% and the capacity is 18 mg/L,the absolute humidity is _____ mg H₂O/L.

A) 10
B) 12
C) 22.5
D) 25.2

Question 27

The relative humidity of an inspired gas is greater than 60% of BTPS.Which of the following statements is true?

A) Production of mucus in the airways will increase.
B) The work of breathing will increase.
C) The airways will function normally.
D) Secretions will become thick and dehydrated.

Question 28

The respiratory therapist has been called because the nasal cannula with humidifier delivering 4 L/min is making a high-pitched whistle.The most probable cause of the problem is that the:

A) humidifier is leaking.
B) oxygen tubing is kinked.
C) oxygen tubing is too long.
D) nasal prong is not in place.

Question 29

Which of the following statements is true concerning bland aerosols?

A) Bland aerosols should not be delivered to patients with tracheostomies.
B) Ultrasonic nebulizers are inefficient at producing bland aerosols.
C) Sterile water and hypotonic, isotonic, and hypertonic solutions can be used.
D) Humidifiers must be heated to deliver bland aerosols.

Question 30

A nonrebreathing mask has been replaced by a high-flow nasal cannula humidifier set at 15 L/min.The benefit of this device to a patient is that it:

A) decreases airway resistance.
B) delivers medication to the airways.
C) prevents an increased humidity deficit.
D) dilutes thick secretions for easy removal.

Question 31

Which of the following humidifiers is classified as passive?

A) Bubble humidifier
B) Large-volume nebulizer
C) Passover humidifier
D) Heat and moisture exchanger

Question 32

The efficiency of a bubble humidifier is affected by which of the following?

A) Gas flow rate
B) Operating pressure
C) Aerosol production
D) Oxygen concentration

Question 33

Which of the following is a true statement about the delivery of warm,humidified gas to the lungs?

A) The gas delivered to the nose or mouth contains 95% relative humidity and has an absolute humidity of 28 mg/L to 34 mg/L at 29° C to 32° C.
B) The gas delivered to the hypopharynx contains 50% relative humidity and has an absolute humidity level of 10 mg/L at 22° C.
C) The gas delivered to the midtrachea contains 50% relative humidity and has an absolute humidity level of 36 mg/L to 40 mg/L at 31° C to 35° C.
D) The gas delivered to the midtrachea contains 100% relative humidity and has an absolute humidity level of 36 mg/L to 40 mg/L at 31° C to 35° C.

Question 34

Appropriate use of an ultrasonic nebulizer will aid which of the following?

A) Ribavirin delivery
B) Sputum induction
C) Croup tent use
D) Pentamidine aerosolization

Question 35

Which of the following statements about humidifiers is appropriate?

A) The warmer the gas, the less water vapor it can hold.
B) Evaporation occurs more rapidly with a large water-to-gas surface area.
C) High peak flows improve the efficacy of a humidifier.
D) The mass of the water is inversely proportional to its capacity to transfer heat.

Question 36

A patient with a nasal cannula set to deliver 8 L/min of oxygen would be expected to report which of the following?
1)Dry,nonproductive cough
2)Increased work of breathing
3)Substernal pain
4)Thick,dehydrated secretions

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

Question 37

If the actual water vapor pressure is 40 mm Hg and the capacity is 55 mm Hg,the relative humidity is:

A) 88%.
B) 85%.
C) 80%.
D) 35%.

Question 38

When the temperature is 37° C and the relative humidity is 35%,the absolute humidity is _____ mg H₂O/L.

A) 11.9
B) 15.4
C) 16.5
D) 79.5

Question 39

A low-flow bubble humidifier is running at 4 L/min and is not whistling.Which action should be taken at this time?

A) No action should be taken because this is normal.
B) Increase the flow to make it whistle.
C) Replace the spring-loaded valve.
D) Change the unit because there is a leak.

Question 40

The efficiency of a bubble humidifier depends on which of the following?
1)Presence of a diffuser
2)Water level in the humidifier
3)Surface area between the gas and water
4)Length of the oxygen tubing being used

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

Question 41

A hypotonic solution with an ultrasonic nebulizer is ordered for a patient who has a history of hyperreactive airways.In such a situation,the respiratory therapist should recommend which of the following?
1)Refuse to give the treatment.
2)Suggest giving a bronchodilator before the hypotonic solution.
3)Suggest that an isotonic solution be used instead.
4)Administer oxygen before the hypotonic solution.

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

Question 42

An ultrasonic nebulizer is being used to deliver a hypotonic solution.The patient suddenly reports shortness of breath.The respiratory therapist auscultates,which reveals wheezing over both lung fields.Which of the following actions should be taken first?
1)Observe the patient.
2)Give the patient oxygen.
3)Add a bronchodilator to the treatment.
4)Immediately stop the treatment.

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

Question 43

Which of the following is not a complication from bland aerosol therapy?

A) Infection
B) Overhydration
C) Bronchospasm
D) Upper airway edema

Question 44

The respiratory therapist needs to deliver a bland aerosol to a 24-month-old child through a spinning disk device.The appropriate flow setting is ___ L/min to ___ L/min.

A) 3; 5
B) 6; 8
C) 10; 15
D) 20; 22

Question 45

You have to set up a continuous heated aerosol to a patient with a tracheostomy.Which of the following pieces of equipment will be needed?
1)Aerosol mask
2)Tracheostomy collar
3)Thermometer
4)Drain bag
5)Oxygen tubing
6)Corrugated tubing
7)Large-volume nebulizer
8)Ultrasonic nebulizer
9)Heating unit
10)Bubble humidifier

A) 1,5,and 10
B) 2,4,6,and 8
C) 1,4,6,7,and 9
D) 2,3,4,6,7,and 9

Question 46

You have been called because of an audible alarm from a heated air-entrainment large-volume jet nebulizer.The most-appropriate immediate action is to:

A) decrease the oxygen flow.
B) change the device to an injection nebulizer.
C) change the device to a high-flow heated humidifier.
D) turn off the heater power to prevent overheating.

Question 47

A heated air-entrainment large-volume jet nebulizer needs to be set up for a patient.In addition to the nebulizer,which of the following pieces of equipment are needed?
1)Heating device
2)Tracheostomy collar
3)Thermometer
4)Aerosol mask
5)Drain bag
6)Oxygen tubing
7)Corrugated tubing

A) 1,2,5,and 7
B) 4 and 7
C) 3,4,5,and 6
D) 1,3,4,5,and 7

Question 48

Which of the following presents the greatest risk for an infant being treated with a heated jet nebulizer?

A) Infection
B) Bronchospasm
C) Overhydration
D) Tachycardia

Question 49

Creation of aerosol particles within a small volume nebulizer is based on:

A) Stokes' law.
B) Brownian motion.
C) the Bernoulli principle.
D) Reynolds' number.

Question 50

Which of the following statements regarding large-volume jet nebulizers is true?

A) Gas is brought down the siphon tube into the liquid.
B) Lateral pressure increases around the air-entrainment ports.
C) Baffling removes the larger particles from the generated aerosol.
D) Inspiratory flow can be increased by closing the air-entrainment ports.

Question 51

The device that presents the least risk of cross-contamination as a room humidifier is which of the following?

A) Bubble humidifier
B) Large-volume nebulizer
C) Wick humidifier
D) Ultrasonic nebulizer

Question 52

A patient wants to use a spinning disk nebulizer at home.The patient should be aware that it:

A) increases the ambient relative humidity.
B) is a mechanical aerosol generator.
C) can be a source of bacterial contamination to the environment.
D) can deliver 20 mL/min.

Question 53

Which of the following devices would be the least effective in reducing a patient's humidity deficit while intubated?

A) A heat and moisture exchanger
B) An unheated bubble humidifier
C) A wick humidifier set at 35° C
D) Heated air-entrainment nebulizer

Question 54

A patient has a heated air-entrainment large-volume jet nebulizer.The aerosol disappears completely during each inspiration.The most-appropriate action to take is to:

A) decrease the oxygen flow to the large-volume nebulizer.
B) increase the oxygen flow to the large-volume nebulizer.
C) decrease the heat level.
D) remove the corrugated reservoir tubing.

Question 55

To produce clinically useful aerosol particles through a small-volume nebulizer,the gas flow rate should be set at ___ L/min to ___ L/min.

A) 12; 15
B) 10; 12
C) 6; 10
D) 3; 6

Question 56

Which of the following is true concerning heat and moisture exchangers?

A) They are passover type A humidifiers.
B) They might reduce the incidence of nosocomial infections.
C) They are best-suited for long-term use on mechanical ventilators.
D) They are able to provide a humidity output of 10 mg/L to 44 mg/L at 35° C.

Question 57

A sputum induction is needed for a 55-year-old female patient.Which of the following devices will be most appropriate?

A) Spinning disk nebulizer
B) Wick humidifier
C) Ultrasonic nebulizer
D) Large-volume jet nebulizer

Question 58

Driving a small-volume nebulizer with heliox,instead of air or oxygen,has what effect on the aerosol produced?

A) Increases upper airway impaction
B) Creates larger particles
C) Decreases the aerosol output
D) Increases the turbulence of the aerosol

Question 59

An individual's humidity deficit will be the smallest when breathing:

A) oxygen through a heated-wick humidifier.
B) room air through a heat and moisture exchanger.
C) room air at 30° C and 50% relative humidity.
D) by nasal cannula (6 L/min) with a bubble humidifier.

Question 60

A respiratory therapist needs to deliver hypotonic solution to a patient through a large-volume jet nebulizer.The gas flow setting should be ___ L/min to ___ L/min.

A) 2; 4
B) 4; 6
C) 6; 8
D) 6; 15

Question 61

Which of the following are the gram-negative bacilli that are responsible for nosocomial infections when aerosol generators are in use?

A) Pseudomonas aeruginosa and Streptococcus pneumoniae
B) Legionella pneumophila and Streptococcus pneumoniae
C) Pseudomonas aeruginosa and Legionella pneumophila
D) Legionella pneumophila and Streptococcus viridans

Question 62

A metered dose inhaler should be held away from the mouth during actuation to:

A) decrease the effect of inertial impaction on the particles.
B) decrease the effect of gravity on the particles.
C) ensure deposition in the oropharynx.
D) prevent cross-contamination.

Question 63

Which of the following will correct the problem of tubing condensation within the ventilator circuit?

A) Water traps
B) Increase the room temperature
C) Hot-wire circuit
D) Both A and C

Question 64

A patient with subglottic edema might benefit from what type of humidity or aerosol therapy?

A) Continuous heated bland aerosol
B) Humidity from a bubble humidifier
C) Continuous cold-nebulized bland aerosol
D) Dry-powder inhaler with a bronchodilator

Question 65

Use of a heat and moisture exchanger is beneficial to a patient with a(n):

A) tracheostomy who is receiving low-flow oxygen.
B) tracheostomy who is receiving room air.
C) open stoma.
D) All of the above.

Question 66

Continuous bland aerosol administration can be hazardous when administered to patients with:
1)asthma.
2)pneumonia.
3)cystic fibrosis.
4)ineffective cough mechanisms.

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

Question 67

One criterion for the use of a dry-powder inhaler is the patient's ability to:

A) coordinate inspiration with actuation.
B) hold the dry-powder inhaler 4 cm from the mouth.
C) empty the powder into the dry-powder inhaler.
D) inspire at flows greater than 40 L/min.

Question 68

Which of the following are contraindications for heat moisture exchanger (HME)use?
1)Hypothermia
2)Uncuffed endotracheal tubes
3)With heated humidification
4)Decrease volume of secretions

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

Question 69

Which of the following are true about the use of a metered dose inhaler?
1)Inertial impaction can be reduced if the patient holds the inhaler in the mouth.
2)Smaller particles will be produced in a cold environment.
3)Larger particles will be produced in a cold environment.
4)The optimum temperature for an inhaler canister is 37° c.
5)The inhaler needs to be shaken before actuation.

A) 1,3,and 4
B) 2 and 4
C) 2 and 5
D) 3,4,and 5

Question 70

Which of the following treatments would provide sufficient humidity to a conscious patient with a core temperature less than 36° C who had nearly drowned?

A) Heat and moisture exchanger
B) Heated aerosol or humidifier
C) Heated aerosol with humidifier
D) Systemic hydration

Question 71

Which of the following devices can be used to administer a continuous bland aerosol?
1)Face tent
2)Simple mask
3)Nonrebreathing mask
4)Tracheostomy collar

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

Question 72

Reactive bronchospasm and increased airway resistance can be caused by:

A) warm humidity.
B) warm aerosol.
C) aerosolized normal saline.
D) cold high-density aerosol.

Question 73

A heat and moisture exchanger is best placed where in the ventilator circuit?

A) Directly at the patient Y-connector
B) Twenty centimeters away from the endotracheal tube
C) At the ventilator outlet
D) At the ventilator inlet

Question 74

Continuous bland aerosol is being delivered to an intubated patient through a large-volume nebulizer and a Briggs adapter.A clinical assessment reveals bronchoconstriction.Which of the following is the most appropriate recommendation?

A) Switch to an ultrasonic nebulizer.
B) Change to a heated-wick humidifier.
C) Add a heater to the large-volume nebulizer.
D) Decrease the flow rate to the large-volume nebulizer.

Question 75

Which of the following devices or methods would be appropriate to provide sufficient humidity for an intubated patient with an uncuffed endotracheal tube who has thick,bloody secretions?

A) Heat and moisture exchanger
B) Heated humidifier
C) Heated humidifier with a heat and moisture exchanger
D) Systemic hydration

Question 76

It is appropriate to suggest which of the following to provide humidification for an intubated patient with a cuffed endotracheal tube,no secretions,and a tidal volume of 500 mL?

A) A heat and moisture exchanger
B) Heated aerosol or humidifier
C) Heated aerosol with humidifier
D) Systemic hydration

Question 77

Which of the following is appropriate to provide humidity to a patient with cold air reactive airways?

A) HME
B) Heated aerosol
C) Heated humidifier
D) Systemic hydration

Question 78

Which of the following is the optimal technique for use of a metered dose inhaler?
1)Actuating the inhaler with the mouthpiece 4 cm from the patient's opened mouth
2)Placing the inhaler in the mouth and closing the lips tightly
3)Holding breath for 5 to 10 seconds after inhalation
4)Not waiting between actuations
5)Inhaling the aerosol quickly

A) 1 and 3
B) 1,3,and 4
C) 2,3,and 5
D) 2,4,and 5

Question 79

Which of the following offers the most accurate and reliable method for measuring the temperature and humidity level within a ventilator circuit?

A) Humidity control of hot-wire humidification system
B) Oxygen analyzer
C) Hygrometer-thermometer
D) Not able to measure humidity level

Question 80

Which of the following offers the best method for delivering ribavirin?

A) A small-volume nebulizer and an aerosol mask
B) An LVN, large-bore tubing, and a Briggs adapter
C) SPAG-2, large-bore tubing, and an oxygen hood
D) SPAG-2, large-bore tubing, and an aerosol mask