Humidity & Aerosol
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.
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?
A.SPAG
B.DPI
C.DPI with holding chamber
D.MDI with holding chamber
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?
A. Oxyhood connected to a blender set at
40% and 10 L/min
B. Heated aerosol mask set at 15 L/min and
40%
C. Venturi mask set at40%
D. Aerosol tent at 40%
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.
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?
A. All 100 ml of aerosol tubing as a reservoir on the T
adaptor
B. Change the O2 to 30% and increase the flow
C. Change the O2 to 40% and decrease the flow
D. Tell the patient not to breathe so deeply
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.
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 ?
A. Handheld nebulizer with 3 cc of normal saline every 4
hours
B. Place the patient into a mist tent
C. Start a continuous ultrasonic nebulizer to an aerosol mask
D. Start a Cascade-type humidifier at 95°F to an aerosol
mask
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
A patient’s humidity deficit is going to be the
smallest under which of the following conditions:
A.Breathing regular hospital room air at 72° f and
40% relative humidity
B.Breathing outside air at 80° F and 50% relative
humidity
C.Breathing 6 L/min of O2 through a nasal cannula
running through an unheated bubble humudufier
D.Breathing 40% O2 through a wick type humidifier
at 95° F to an aerosol mask
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
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
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.
Your patient has a temperature of 98.6° F.
To saturate the inhaled air, how much
absolute humidity must be provided by
the humidifier?
A.37° C
B.47 mmHg
C.760 mmHg
D.44 mg/L
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
0.45. 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.
The End
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?
A.1 to 3 micrometers
B.2 to 5 micrometers
C.5 to 7 micrometers
D.10 micrometers or larger
An ultrasonic nebulizer would be recommended for
aerosol therapy for the following reason:
A.It delivers a wide variety of aerosol droplets
B.Its aerosol droplets are between 10 and 20
micrometers in diameter
C.It delivers uniform aerosol droplets of about 4 - 6
micrometers in diameter
D.It can be used to nebulize bland aerosols and
liquid medications into an aerosol
Your patient has an endotracheal tube. Which of
the following devices would be the least effective
in reducing this patient’s humidity deficit?
A.Wick-type humidifier set at 35° C
B.Cascade –type humidifer set at 35°
C.Unheated bubble humidifier
D.Ultrasonic humidifier
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?
I. Condensation will occur
II. The gas will warm and expand as it travels to the
patient
III. The gas will remain saturated
IV. The relative humidity will decrease
V. The relative humidity will increase
A. I and III
B. IV
C. I and V
D. I and IV