Question 1

A heated humidifier should trigger both auditory and visual alarms and interrupt power to the heater when the delivered temperature exceeds which of the following?

Accepted Answer

The delivered temperature should not exceed 37°C to prevent thermal injury to the patient. A temperature of 40°C is well above the safe range, and alarms should be triggered to prevent harm to the patient. Therefore, choice D is the best choice.

Question 2

Which of the following are necessary features to look for in selecting a heated humidifier?
1) Water level readily visible
2) Over-temperature protection
3) Auditory and visual alarms
4) Minimal temperature overshoot

Accepted Answer

All listed features are important for the safety and effectiveness of a heated humidifier. A visible water level ensures the device is properly filled, over-temperature protection prevents overheating, auditory and visual alarms alert users to issues, and minimal temperature overshoot ensures the device heats to the intended temperature without exceeding it.

Question 3

Which of the following are contraindications for heat and moisture exchangers?
1) Presence of thick, copious, or bloody secretions
2) Presence of a large leak around artificial airway
3) When a patient is suffering from hyperpyrexia
4) When a patient's minute ventilation exceeds 10 L/min

Accepted Answer

Heat and moisture exchangers are contraindicated in the presence of thick, copious, or bloody secretions because they can clog the device. A large leak around the artificial airway can also compromise the effectiveness of the heat and moisture exchanger. When a patient's minute ventilation exceeds 10 L/min, the device may not be able to adequately condition the increased airflow, making these situations contraindications. Hyperpyrexia (extremely high fever) is not specifically a contraindication for using heat and moisture exchangers.

Question 4

The temperature of gas delivered to a patient's airway by a servo-controlled heated humidifier should not vary by more than how much?

Accepted Answer

The temperature of gas delivered to a patient's airway by a servo-controlled heated humidifier should not vary by more than 2° C to ensure patient safety and comfort.

Question 5

An ideal heat and moisture exchanger (HME) should have an efficiency rating of at least which of the following?

Accepted Answer

The ideal HME should operate at 70% efficiency or better.

Question 6

A patient receiving ventilatory support is being provided with humidification using a heat and moisture exchanger (HME). A physician orders a bronchodilator drug administered through a metered dose inhaler (MDI) via the ventilator circuit. Which of the following must be performed to ensure delivery of the drug to the patient?

Accepted Answer

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

Question 7

Which of the following statements is false of heat and moisture exchangers (HMEs)?

Accepted Answer

As shown in Table 38-3, the moisture output of HMEs tends to fall at high volumes and rates of breathing. In addition, high inspiratory flows and high FiO₂ levels can decrease HME efficiency. Flow resistance through the HME also is important. When an HME is dry, resistance across most devices is minimal. However, because of water absorption, HME flow resistance increases after several hours' use. For some patients, the increased resistance imposed by the HME may not be well tolerated, particularly if the underlying lung disease already causes increased work of breathing. Because HMEs eliminate the problem of breathing-circuit condensation, many consider these devices (especially hydrophobic filter HMEs) to be helpful in preventing nosocomial infections.

Question 8

Which of the following automatic feed systems are used to regulate water levels when using a humidifier with a continuous feed system?
1) Leveling reservoirs
2) Flotation controls
3) Optical sensors

Accepted Answer

All three options, leveling reservoirs, flotation controls, and optical sensors, are methods used to regulate water levels in various systems, including humidifiers with continuous feed systems. Leveling reservoirs help maintain a constant water level, flotation controls use the principle of buoyancy to adjust water flow, and optical sensors can detect water levels and adjust accordingly.

Question 9

Which of the following are potential hazards of using a heated humidifier during mechanical ventilation?
1) Aerosolization of condensate during disconnection
2) Underhydration or impaction of secretions
3) Hypoventilation due to increased dead space
4) Unintended tracheal lavage from condensate

Accepted Answer

1) Aerosolization of condensate during disconnection is a potential hazard because it could lead to the spread of infectious agents. 
2) Underhydration or impaction of secretions is a potential hazard because the humidifier could over-humidify the airway or cause secretions to become too thick, leading to potential airway obstruction. 
3) Hypoventilation due to increased dead space is a potential hazard because the increased volume of the heated humidifier could add to the ventilator circuit's dead space, leading to hypoventilation. 
4) Unintended tracheal lavage from condensate is a potential hazard because it could lead to aspiration or infection.

Question 10

A patient receiving nasal O₂ at 3 L/min complains of nasal dryness and irritation. Which of the following actions would be appropriate?

Accepted Answer

For the occasional patient who complains of nasal dryness or irritation when receiving low-flow O₂, a humidifier should be added to the delivery system.

Question 11

What are some potential problems with manually refilled heated humidifier reservoirs?
1) Cross contamination and infection
2) Variable compliance or delivered volume
3) Delivery of dry and/or hot gases

Accepted Answer

Manually refilled heated humidifier reservoirs can lead to cross contamination and infection due to improper handling, variable compliance or delivered volume due to inconsistent refilling practices, and the delivery of dry and/or hot gases if the humidification system is not properly managed.

Question 12

Which of the following is false about a simple heated humidifier (one that does not incorporate a servo-control mechanism)?

Accepted Answer

Humidifier heating systems also have a controller that regulates the element's electric power. In the simplest systems, the controller monitors the heating element, varying the delivered current to match either a preset or an adjustable temperature. In these systems, the patient's airway temperature has no effect on the controller.

Question 13

Which of the following are potential hazards of using heat and moisture exchangers?
1) Failure of low-pressure alarms to detect disconnection
2) Underhydration or impaction of secretions
3) Hypoventilation due to increased dead space
4) Unintended tracheal lavage from condensate

Accepted Answer

1) Failure of low-pressure alarms to detect disconnection: This is a potential risk of using heat and moisture exchangers. The low-pressure alarms may not detect disconnections, and the patient may not receive enough oxygen.
2) Underhydration or impaction of secretions: This is a potential hazard but is not specific to heat and moisture exchangers.
3) Hypoventilation due to increased dead space: Heat and moisture exchangers may increase dead space, leading to hypoventilation. This is a potential risk.
4) Unintended tracheal lavage from condensate: This is a potential hazard but is not specific to heat and moisture exchangers.

Question 14

For which of the following patients would you select a heated humidifier? 1) Patient receiving O₂ through a bypassed upper airway 2) Patient receiving long-term mechanical ventilation 3) Patient receiving O₂ through an oronasal mask

Accepted Answer

Heated humidifiers are often used for patients with bypassed upper airways (e.g., tracheostomy) and those receiving long-term mechanical ventilation to prevent drying of the airways and to ensure the air is adequately humidified, enhancing comfort and respiratory function.

Question 15

When using a servo-controlled heated humidifier to deliver gas to an infant, the thermistor probe should be placed where?

Accepted Answer

Place heated humidifier thermistor probes in the inspiratory limb of a ventilator circuit far enough from the patient Y adaptor to ensure that warm exhaled gas does not fool the controller system. Never place a thermistor probe in an isolette or a radiant warmer, where the probe is warmed externally and the humidifier is fooled into shutting down, reducing the humidity available to the patient.

Question 16

Where should you place the thermistor probe for a servo-controlled heated humidifier being used on a patient receiving mechanical ventilation?

Accepted Answer

The answer of Where should you place the thermistor probe...

Question 17

Conditions that can cause temperature "overshoot" with servo-controlled heated humidifiers include which of the following?
1) The unit is allowed to warm up without flow.
2) Flow is decreased during normal operation.
3) The airway temperature probe becomes dislodged.
4) The unit reservoir is refilled with sterile water.

Accepted Answer

All three conditions listed (1, 2, and 3) can cause temperature overshoot with servo-controlled heated humidifiers, while refilling the reservoir with sterile water (condition 4) is not directly related to temperature control.

Question 18

Which of the following are features of an ideal heat and moisture exchanger (HME)?
1) High compliance
2) Minimal dead space
3) 70% or higher efficiency
4) Minimal flow resistance

Accepted Answer

The answer of Which of the following are features of...

Question 19

What should happen when the remote temperature sensor of a heated humidifier becomes disconnected or fails?
1) Power to the heater should be interrupted.
2) Auditory and visual alarms should trigger.
3) The unit's outlet valve should lock closed.

Accepted Answer

When the remote temperature sensor of a heated humidifier becomes disconnected or fails, power to the heater should be interrupted to prevent overheating or underheating, and auditory and visual alarms should trigger to alert the user to the malfunction. There is no need for the unit's outlet valve to lock closed, as this action does not directly relate to the function of the temperature sensor or the safety measures needed in such a scenario.

Question 20

Characteristics of a servo-controlled heated humidifier include which of the following?
1) Monitors heater temperature.
2) Adjusts heater power automatically.
3) Provides automatic heater shutdown.
4) Includes temperature safety alarms.

Accepted Answer

A servo-controlled heated humidifier adjusts heater power automatically, provides automatic heater shutdown, and includes temperature safety alarms to ensure safe and effective operation.

Quiz 38: Humidity and Bland Aerosol Therapy

A heated humidifier should trigger both auditory and visual alarms and interrupt power to the heater when the delivered temperature exceeds which of the following?

Which of the following are necessary features to look for in selecting a heated humidifier? 1) Water level readily visible 2) Over-temperature protection 3) Auditory and visual alarms 4) Minimal temperature overshoot

Which of the following are contraindications for heat and moisture exchangers? 1) Presence of thick, copious, or bloody secretions 2) Presence of a large leak around artificial airway 3) When a patient is suffering from hyperpyrexia 4) When a patient's minute ventilation exceeds 10 L/min

The temperature of gas delivered to a patient's airway by a servo-controlled heated humidifier should not vary by more than how much?

An ideal heat and moisture exchanger (HME) should have an efficiency rating of at least which of the following?

Which of the following statements is false of heat and moisture exchangers (HMEs) ?

Which of the following automatic feed systems are used to regulate water levels when using a humidifier with a continuous feed system? 1) Leveling reservoirs 2) Flotation controls 3) Optical sensors

Which of the following are potential hazards of using a heated humidifier during mechanical ventilation? 1) Aerosolization of condensate during disconnection 2) Underhydration or impaction of secretions 3) Hypoventilation due to increased dead space 4) Unintended tracheal lavage from condensate

A patient receiving nasal O₂ at 3 L/min complains of nasal dryness and irritation. Which of the following actions would be appropriate?

What are some potential problems with manually refilled heated humidifier reservoirs? 1) Cross contamination and infection 2) Variable compliance or delivered volume 3) Delivery of dry and/or hot gases

Which of the following is false about a simple heated humidifier (one that does not incorporate a servo-control mechanism) ?

Which of the following are potential hazards of using heat and moisture exchangers? 1) Failure of low-pressure alarms to detect disconnection 2) Underhydration or impaction of secretions 3) Hypoventilation due to increased dead space 4) Unintended tracheal lavage from condensate

For which of the following patients would you select a heated humidifier? 1) Patient receiving O₂ through a bypassed upper airway 2) Patient receiving long-term mechanical ventilation 3) Patient receiving O₂ through an oronasal mask

When using a servo-controlled heated humidifier to deliver gas to an infant, the thermistor probe should be placed where?

Where should you place the thermistor probe for a servo-controlled heated humidifier being used on a patient receiving mechanical ventilation?

Which of the following are features of an ideal heat and moisture exchanger (HME) ? 1) High compliance 2) Minimal dead space 3) 70% or higher efficiency 4) Minimal flow resistance

What should happen when the remote temperature sensor of a heated humidifier becomes disconnected or fails? 1) Power to the heater should be interrupted. 2) Auditory and visual alarms should trigger. 3) The unit's outlet valve should lock closed.

Characteristics of a servo-controlled heated humidifier include which of the following? 1) Monitors heater temperature. 2) Adjusts heater power automatically. 3) Provides automatic heater shutdown. 4) Includes temperature safety alarms.

Quiz 38: Humidity and Bland Aerosol Therapy

A heated humidifier should trigger both auditory and visual alarms and interrupt power to the heater when the delivered temperature exceeds which of the following?

Which of the following are necessary features to look for in selecting a heated humidifier? 1) Water level readily visible 2) Over-temperature protection 3) Auditory and visual alarms 4) Minimal temperature overshoot

Which of the following are contraindications for heat and moisture exchangers? 1) Presence of thick, copious, or bloody secretions 2) Presence of a large leak around artificial airway 3) When a patient is suffering from hyperpyrexia 4) When a patient's minute ventilation exceeds 10 L/min

The temperature of gas delivered to a patient's airway by a servo-controlled heated humidifier should not vary by more than how much?

An ideal heat and moisture exchanger (HME) should have an efficiency rating of at least which of the following?

Which of the following statements is false of heat and moisture exchangers (HMEs) ?

Which of the following automatic feed systems are used to regulate water levels when using a humidifier with a continuous feed system? 1) Leveling reservoirs 2) Flotation controls 3) Optical sensors

Which of the following are potential hazards of using a heated humidifier during mechanical ventilation? 1) Aerosolization of condensate during disconnection 2) Underhydration or impaction of secretions 3) Hypoventilation due to increased dead space 4) Unintended tracheal lavage from condensate

A patient receiving nasal O2 at 3 L/min complains of nasal dryness and irritation. Which of the following actions would be appropriate?

What are some potential problems with manually refilled heated humidifier reservoirs? 1) Cross contamination and infection 2) Variable compliance or delivered volume 3) Delivery of dry and/or hot gases

Which of the following is false about a simple heated humidifier (one that does not incorporate a servo-control mechanism) ?

Which of the following are potential hazards of using heat and moisture exchangers? 1) Failure of low-pressure alarms to detect disconnection 2) Underhydration or impaction of secretions 3) Hypoventilation due to increased dead space 4) Unintended tracheal lavage from condensate

For which of the following patients would you select a heated humidifier? 1) Patient receiving O2 through a bypassed upper airway 2) Patient receiving long-term mechanical ventilation 3) Patient receiving O2 through an oronasal mask

When using a servo-controlled heated humidifier to deliver gas to an infant, the thermistor probe should be placed where?

Where should you place the thermistor probe for a servo-controlled heated humidifier being used on a patient receiving mechanical ventilation?

Which of the following are features of an ideal heat and moisture exchanger (HME) ? 1) High compliance 2) Minimal dead space 3) 70% or higher efficiency 4) Minimal flow resistance

What should happen when the remote temperature sensor of a heated humidifier becomes disconnected or fails? 1) Power to the heater should be interrupted. 2) Auditory and visual alarms should trigger. 3) The unit's outlet valve should lock closed.

Characteristics of a servo-controlled heated humidifier include which of the following? 1) Monitors heater temperature. 2) Adjusts heater power automatically. 3) Provides automatic heater shutdown. 4) Includes temperature safety alarms.

A patient receiving nasal O₂ at 3 L/min complains of nasal dryness and irritation. Which of the following actions would be appropriate?

For which of the following patients would you select a heated humidifier? 1) Patient receiving O₂ through a bypassed upper airway 2) Patient receiving long-term mechanical ventilation 3) Patient receiving O₂ through an oronasal mask