1. Humidity & Aerosol

2. B. remain 100% and excess water will rain out.
A gas is saturated with 100% relative humidity at 32.2 ° C (90 ° F). As the gas cools to 26.7 ° C (80 ° F), the relative humidity will
A. increase by 10%.
B. remain 100% and excess water will rain out.
C. decrease as a result of cooling of the gas.
D. decrease as water condenses.
EXPLANATIONS:
(u) A. Relative humidity greater than 100% is impossible.
(c) B. Reduction in temperature will result in a constant 100% relative humidity and cause water vapor to condense ("rain out").
(u) C. Although condensation will occur as the gas cools, it will still remain fully saturated at its given temperature, and therefore the relative humidity will remain at 100%.
(u) D. Although condensation will occur as the gas cools, it will still remain fully saturated at its given temperature, and therefore the relative humidity will remain at 100%.

3. DPI with holding chamber MDI with holding chamber
A 4-year-old asthma patient is about to be discharged and needs to take an inhaled bronchodilator medication at home. What device would you recommend be used?
SPAG
DPI
DPI with holding chamber
MDI with holding chamber
A is for Ribavirin
B not recommend for young children because they cannot generate the required flow rate
C do not come with holding chambers
D Correct

4. A 2-year old child recently diagnosed with laryngotracheobronchitis requires the administration of 40% oxygen. What is the most appropriate method for delivering the oxygen?
Oxyhood connected to a blender set at 40% and 10 L/min
Heated aerosol mask set at 15 L/min and 40%
Venturi mask set at40%
Aerosol tent at 40%

5. A heat moisture exchanger is most appropriate for a patient
A. who is receiving noninvasive positive pressure ventilation.
B. with ARDS who is receiving mechanical ventilation.
C. who is receiving mechanical ventilation in the PACU.
D. with a bronchopleural fistula who is receiving mechanical ventilation.
EXPLANATIONS:
(u) A. Noninvasive positive pressure ventilation does not use an artificial airway.
(u) B. A patient with ARDS will require mechanical ventilation and humidification for several days. See explanation C.
(c) C. A heat moisture exchanger should be considered for short-term mechanical ventilation.
(a) D. A heat moisture exchanger is contraindicated in a bronchopleural fistula.

6. All 100 ml of aerosol tubing as a reservoir on the T adaptor
A comatose patient is intubated and receiving 35% O2 with aerosol through a T-adaptor. While watching the patient breathe, you notice that during each inspiration the mist disappears from the downstream end of the T-adapter. What would you recommend?
All 100 ml of aerosol tubing as a reservoir on the T adaptor
Change the O2 to 30% and increase the flow
Change the O2 to 40% and decrease the flow
Tell the patient not to breathe so deeply
It is a good idea to also increase the flow, however a is the best answer because it does not require changing the FiO2

7. A. Operation is most efficient at room temperature.
What is a major advantage of a wick humidifier compared with other types of humidifiers?
A. Operation is most efficient at room temperature.
B. Both molecular and particulate water are produced.
C. A relative humidity of 100% is easily produced.
D. A baffle is not needed to produce the desired humidity.
EXPLANATIONS:
(u) A. Operation is not meant to be at room temperature.
(u) B. A wick humidifier produces water vapor only.
(c) C. Due to heating and a large damp surface area, high humidity is produced.
(u) D. Since particulate water is not produced, a baffle is not necessary.

8. A physician calls you to evaluate a 40-year-old patient with bronchitis and make a recommendation for an aerosol delivery system. The patient’s breath sounds indicate the presence of large airway secretions. Despite a good cough effort the patient has difficulty expectorating them. What would you recommend ?
Handheld nebulizer with 3 cc of normal saline every 4 hours
Place the patient into a mist tent
Start a continuous ultrasonic nebulizer to an aerosol mask
Start a Cascade-type humidifier at 95°F to an aerosol mask

9. A. entraining water from the capillary tube
Which of the following is the major function of the baffle in a nebulizer?
A. entraining water from the capillary tube
B. providing aerosol particles that are consistently small
C. mixing aerosol particles with the main gas flow
D. promoting laminar inspiratory flow
EXPLANATIONS:
(u) A. The capillary tube delivers water from the reservoir to the jet.
(c) B. An object that is in the path of the aerosol stream can function as a baffle to cause larger particles to return to the liquid reservoir and only allow small particles to travel on to the patient through the gas stream.
(u) C. A baffle usually prevents larger aerosol particles from entering the main gas flow.
(u) D. Baffles cause turbulent flow, enhancing the return of larger particles to the reservoir.

10. Breathing regular hospital room air at 72° f and 40% relative humidity
A patient’s humidity deficit is going to be the smallest under which of the following conditions:
Breathing regular hospital room air at 72° f and 40% relative humidity
Breathing outside air at 80° F and 50% relative humidity
Breathing 6 L/min of O2 through a nasal cannula running through an unheated bubble humudufier
Breathing 40% O2 through a wick type humidifier at 95° F to an aerosol mask
Highest temp, holds most water, and most efficient humidifier

11. A. ultrasonic nebulizer B. large volume jet nebulizer
Which of the following devices can provide the greatest total fluid output?
A. ultrasonic nebulizer
B. large volume jet nebulizer
C. bubble humidifier
D. heated Cascade humidifier
EXPLANATIONS:
(c) A. An ultrasonic nebulizer has the ability to produce up to 6.0 mL/min of particulate water with 100% relative humidity of the gas.
(u) B. A large volume jet nebulizer has the ability to produce approximately 1.5 mL/min of particulate water with 100% relative humidity of the gas.
(u) C. A bubble humidifier would deliver 40% relative humidity to the patient.
(u) D. A heated Cascade humidifier can produce 100% relative humidity at body temperature; however, it cannot produce particulate water and does not meet or exceed the output of the ultrasonic nebulizer.

12. A. decreased temperature within the canopy
Which of the following is the most probable cause of insufficient aerosol output in a mist tent?
A. decreased temperature within the canopy
B. compressor switch in the off position
C. overfilled condensate bottle
D. a clogged capillary tube in the nebulizer
EXPLANATIONS:
(u) A. A decrease in the temperature inside the tent canopy does not cause a decrease in the mist.
(u) B. The compressor switch position does not affect aerosol output.
(u) C. Overfilling the condensate bottle does not affect aerosol output.
(c) D. If the capillary tube in the nebulizer is not drawing liquid, the mist will be decreased.

13. A. Increase the flowmeter from 5 to 8 L/min.
The respiratory therapist is called to check an oxyhood in the NICU. The unit is using a large volume nebulizer and an air/oxygen blender with a flowmeter. The therapist notes the pressure pop-off valve on the nebulizer is chattering. Which of the following actions is required?
A. Increase the flowmeter from 5 to 8 L/min.
B. Check the tubing to the oxyhood for an obstruction.
C. Reposition the capillary tube in the nebulizer.
D. Tighten the high pressure supply line connections to the blender.
EXPLANATIONS:
(u) A. An increase of 3 L/min would increase back pressure and would not correct this problem.
(c) B. An obstruction to the nebulizer outlet could cause the pressure pop-off valve to chatter.
(u) C. A malfunctioning capillary tube would affect nebulization, but not the pop-off valve.
(u) D. The 50 psi gas source does not contribute to activating the pop-off valve.

14. Your patient has a temperature of 98. 6° F
Your patient has a temperature of 98.6° F. To saturate the inhaled air, how much absolute humidity must be provided by the humidifier?
37° C
47 mmHg
760 mmHg
44 mg/L

15. A. Clear the nebulizer jet. B. Replace the nebulizer.
A patient is receiving an F I O 2 of 0.40 by a heated nebulizer connected to a T-piece. Five hours later, the F I O 2 analyzed at the nebulizer side of the T-piece is Which of the following should the respiratory therapist do to correct the problem?
A. Clear the nebulizer jet.
B. Replace the nebulizer.
C. Empty the condensate from the aerosol tubing.
D. Increase the flow to the nebulizer.
EXPLANATIONS:
(a) A. Clearing the nebulizer jet may improve nebulizer performance, but will usually not affect F I O 2 .
(u) B. Replacing the nebulizer is not necessary. Clearing the tubing of condensate should correct the problem.
(c) C. Condensate in the tubing would cause a higher F I O 2 by increasing back pressure to the air entrainment port, therefore reducing the dilution of oxygen with air.
(u) D. Increasing the flow might increase the delivered F I O 2 and would not correct the problem.

16. The End

17. To help prepare a patient for a laryngoscopy procedure, the physician has ordered her to inhale nebulized lidocaine (Xylocaine). You would select a nebulizer that generates what size particles?
1 to 3 micrometers
2 to 5 micrometers
5 to 7 micrometers
10 micrometers or larger

18. An ultrasonic nebulizer would be recommended for aerosol therapy for the following reason:
It delivers a wide variety of aerosol droplets
Its aerosol droplets are between 10 and 20 micrometers in diameter
It delivers uniform aerosol droplets of about micrometers in diameter
It can be used to nebulize bland aerosols and liquid medications into an aerosol

19. Your patient has an endotracheal tube
Your patient has an endotracheal tube. Which of the following devices would be the least effective in reducing this patient’s humidity deficit?
Wick-type humidifier set at 35° C
Cascade –type humidifer set at 35°
Unheated bubble humidifier
Ultrasonic humidifier

20. Your heated humidifier unit has a water reservoir temperature of 40°C
Your heated humidifier unit has a water reservoir temperature of 40°C. The humidified gas is traveling through large bore tubing to the patient. Which of the following statements are true?
Condensation will occur
The gas will warm and expand as it travels to the patient
The gas will remain saturated
The relative humidity will decrease
The relative humidity will increase
A. I and III
B. IV
C. I and V
D. I and IV