Question 1

When is a heat and moisture exchanger (HME) performing well?

Accepted Answer

Lacking direct measurement of humidity, observation of this minimal condensate is the most reliable indicator that the gas is fully saturated at the specified temperature.

Question 2

Hazards and complications of bland aerosol therapy include which of the following?
1) Bronchospasm
2) Overhydration
3) Infection
4) Hemoconcentration

Accepted Answer

Bland aerosol therapy can lead to bronchospasm, especially in patients with reactive airway disease, due to the cooling or drying effect of the aerosol. Overhydration is a risk when excessive amounts of fluid are inhaled, particularly in patients with compromised lung function. Infection risk increases due to potential contamination of the aerosol solution or equipment. Hemoconcentration is not typically associated with bland aerosol therapy.

Question 3

Which of the following are the proper temperature alarm settings for a heated humidifier used during mechanical ventilation? High Low

Accepted Answer

The AARC has published Clinical Practice Guideline: Humidification During Mechanical Ventilation. Excerpts are in CPG 38-1.

Question 4

In checking a servo-controlled heated-wire humidifier system, you notice that a few drops of condensate tend to form but only near the patient's airway. Based on this observation, what can you conclude?

Accepted Answer

To ensure that the inspired gas is being properly conditioned, clinicians should always adjust the temperature differential to the point that a few drops of condensation form near the patient "wye." Lacking direct measurement of humidity, observation of this minimal condensate is the most reliable indicator that the gas is fully saturated at the specified temperature.

Question 5

Which of the following is false about heated humidifier condensate?

Accepted Answer

Condensation can disrupt or occlude gas flow through the circuit, potentially altering FiO₂ and/or ventilator function. Moreover, condensate can work its way toward the patient and be aspirated. For these reasons, circuits must be positioned to drain condensate away from the patient and must be checked often, and excess condensate must be drained from heated humidifier breathing circuits on a regular basis. Typically, patients contaminate ventilator circuits within hours, and condensate is colonized with bacteria and thus poses an infection risk. To avoid problems in this area, health care personnel should treat all breathing-circuit condensate as infectious waste.

Question 6

For which of the following patients might you recommend administration of a hypertonic saline aerosol?
1) Acquired immune deficiency syndrome (AIDS) patient with severe pneumonia symptoms
2) Patient with a bypassed upper airway
3) Patient suspected of having tuberculosis

Accepted Answer

The answer of For which of the following patients might...

Question 7

Which of the following are acceptable means to help minimize the problems caused by condensation in heated humidifier circuits?
1) Installing water traps in the circuit
2) Using a heated-wire circuit
3) Setting heater temperature to 25° to 28° C

Accepted Answer

Installing water traps and using a heated-wire circuit are effective methods to minimize condensation in humidifier circuits. Setting the heater temperature to 25° to 28° C is not typically effective for this purpose.

Question 8

During routine use on an intubated patient, a heated humidifier should deliver inspired gas at which of the following?

Accepted Answer

The AARC has published Clinical Practice Guideline: Humidification During Mechanical Ventilation. Excerpts are in CPG 38-1.

Question 9

When using nebulizers, where should you place them to minimize risk of contamination?

Accepted Answer

To minimize this risk, place nebulizers in a superior position, so that any condensate travels downstream from the nebulizer.

Question 10

A patient has been supported by a mechanical ventilator using a heat and moisture exchanger for the last 3 days. Suctioning reveals an increase in the amount and tenacity of secretions. Which of the following actions is indicated?

Accepted Answer

The AARC has published Clinical Practice Guideline: Humidification During Mechanical Ventilation. Excerpts are in CPG 38-1.

Question 11

Which of the following barrier precautions should be used when heated humidifier circuits are changed or removed?
1) Wearing gloves
2) Wearing goggles
3) 5-min hand scrub

Accepted Answer

When heated humidifier circuits are changed or removed, it is recommended to use gloves and goggles as barrier precautions. These precautions help prevent exposure to any potential infectious material that may be present in the circuit, as well as protect the healthcare worker from any splashing or spraying that may occur during the process. A 5-minute hand scrub is not specified as a recommended barrier precaution in this scenario.

Question 12

For which of the following patients would you recommend bland aerosol therapy administration?
1) Patient with a history of airway hyperresponsiveness
2) Patient with a bypassed upper airway
3) Patient with active bronchoconstriction

Accepted Answer

Bland aerosol therapy is recommended for patients with a bypassed upper airway to help maintain airway moisture, as they cannot benefit from the natural humidification process. Patients with airway hyperresponsiveness or active bronchoconstriction may experience worsening symptoms with aerosol therapy, making it less suitable for these conditions.

Question 13

The amount of condensation occurring in a heated, humidified gas delivery system depends on which of the following?
1) Length, diameter, and mass of the circuit
2) Temperature differential along the circuit
3) Ambient temperature
4) Rate of gas flow through the circuit

Accepted Answer

The amount of condensation in a heated, humidified gas delivery system is influenced by the length, diameter, and mass of the circuit (which affect heat retention and loss), the temperature differential along the circuit (which affects the point at which condensation occurs), the ambient temperature (which can influence the temperature differential and thus condensation), and the rate of gas flow through the circuit (which can affect both the temperature and the amount of moisture the gas can carry).

Question 14

When using water traps to help minimize the problems caused by condensation in a heated-humidifier ventilator circuit, where would you place the traps?

Accepted Answer

One common method is to place water traps at low points in the circuit (both the inspiratory and expiratory limbs of ventilator circuits).

Question 15

How often should heat and moisture exchangers be inspected and replaced?

Accepted Answer

The AARC has published Clinical Practice Guideline: Humidification During Mechanical Ventilation. Excerpts are in CPG 38-1.

Question 16

When checking a patient attached to a servo-controlled heated-wire humidifier breathing circuit, you notice no visible condensate anywhere in the tubing. Based on this observation, you can conclude that the relative humidity of the delivered gas is which of the following?

Accepted Answer

If condensate cannot be seen, there is no way of knowing the level of relative humidity without direct measurement-it could be anywhere between 99% and 0%.

Question 17

For which of the following patients might you recommend bland aerosol therapy administration?
1) Patient with upper airway edema
2) Patient with a bypassed upper airway
3) Patient who must provide a sputum specimen

Accepted Answer

Bland aerosol therapy is beneficial for patients with upper airway edema to reduce swelling, for those with a bypassed upper airway to maintain airway moisture, and for patients needing to provide a sputum specimen by helping to mobilize secretions.

Question 18

Which of the following reduce the risk of nosocomial infection when using heated humidification systems?
1) Use of wick or membrane humidifiers
2) Use of heated-wire delivery circuits
3) High humidifier reservoir temperatures
4) Frequent changing of delivery circuits

Accepted Answer

1) Wick or membrane humidifiers reduce contamination risk by minimizing the aerosolization of water. 2) Heated-wire circuits prevent condensation, reducing the risk of microbial growth. 3) High temperatures can help to kill or inhibit the growth of pathogens.

Question 19

Which of the following are true when heated-wire circuits are used with heated humidifiers except:

Accepted Answer

When heated-wire circuits are used, the humidifier heats gas to a lower temperature (32° to 40° C) than it does with conventional circuits (45° to 50° C). The reduction in condensate in the tubing results in less water use, reduced need for drainage, and less infection risk for both patient and health care workers.

Question 20

What is the most reliable indicator that the gas delivered by a servo-controlled heated-wire humidifier system is fully saturated at the airway?

Accepted Answer

To ensure that the inspired gas is being properly conditioned, clinicians should always adjust the temperature differential to the point that a few drops of condensation form near the patient "wye." Lacking direct measurement of humidity, observation of this minimal condensate is the most reliable indicator that the gas is fully saturated at the specified temperature.

Quiz 38: Humidity and Bland Aerosol Therapy

When is a heat and moisture exchanger (HME) performing well?

Hazards and complications of bland aerosol therapy include which of the following? 1) Bronchospasm 2) Overhydration 3) Infection 4) Hemoconcentration

Which of the following are the proper temperature alarm settings for a heated humidifier used during mechanical ventilation? High Low

In checking a servo-controlled heated-wire humidifier system, you notice that a few drops of condensate tend to form but only near the patient's airway. Based on this observation, what can you conclude?

Which of the following is false about heated humidifier condensate?

For which of the following patients might you recommend administration of a hypertonic saline aerosol? 1) Acquired immune deficiency syndrome (AIDS) patient with severe pneumonia symptoms 2) Patient with a bypassed upper airway 3) Patient suspected of having tuberculosis

Which of the following are acceptable means to help minimize the problems caused by condensation in heated humidifier circuits? 1) Installing water traps in the circuit 2) Using a heated-wire circuit 3) Setting heater temperature to 25° to 28° C

During routine use on an intubated patient, a heated humidifier should deliver inspired gas at which of the following?

When using nebulizers, where should you place them to minimize risk of contamination?

A patient has been supported by a mechanical ventilator using a heat and moisture exchanger for the last 3 days. Suctioning reveals an increase in the amount and tenacity of secretions. Which of the following actions is indicated?

Which of the following barrier precautions should be used when heated humidifier circuits are changed or removed? 1) Wearing gloves 2) Wearing goggles 3) 5-min hand scrub

For which of the following patients would you recommend bland aerosol therapy administration? 1) Patient with a history of airway hyperresponsiveness 2) Patient with a bypassed upper airway 3) Patient with active bronchoconstriction

The amount of condensation occurring in a heated, humidified gas delivery system depends on which of the following? 1) Length, diameter, and mass of the circuit 2) Temperature differential along the circuit 3) Ambient temperature 4) Rate of gas flow through the circuit

When using water traps to help minimize the problems caused by condensation in a heated-humidifier ventilator circuit, where would you place the traps?

How often should heat and moisture exchangers be inspected and replaced?

When checking a patient attached to a servo-controlled heated-wire humidifier breathing circuit, you notice no visible condensate anywhere in the tubing. Based on this observation, you can conclude that the relative humidity of the delivered gas is which of the following?

For which of the following patients might you recommend bland aerosol therapy administration? 1) Patient with upper airway edema 2) Patient with a bypassed upper airway 3) Patient who must provide a sputum specimen

Which of the following reduce the risk of nosocomial infection when using heated humidification systems? 1) Use of wick or membrane humidifiers 2) Use of heated-wire delivery circuits 3) High humidifier reservoir temperatures 4) Frequent changing of delivery circuits

Which of the following are true when heated-wire circuits are used with heated humidifiers except:

What is the most reliable indicator that the gas delivered by a servo-controlled heated-wire humidifier system is fully saturated at the airway?