Humidity and Bland Aerosol Therapy

Question 1

Humidity and Temperature during normal breathing

Answer 1

Gases delivered to the nose and mouth should be conditioned to 22’C with 10 mg/L water vapor (50% relative humidity RH)

When being delivered to the trachea, gases should be warmed and humidified to 36’C with 35mg/L water vapor (>90% relative humidity)

22’C 10mg/L&raquo_space;> 36’C 35mg/L&raquo_space;> 37’C 44mg/L
32’C 34 mg/L«< 42mg/L«<37’C 44mg/L

Question 2

What is the humidifier?

Answer 2

It is a device that adds invisible molecular water to gas.

Question 3

What is a nebulizer?

Answer 3

A nebulizer generates and disperses liquid particles in a gas stream.
It is a drug delivery device used to administer medication.
Bland aerosols in the form of a mist that can be inhaled into the lungs

Question 4

T/F Water vapor (Humidity) CANNOT carry pathogens.

Answer 4

True

Question 5

T/F Aerosols and condensate CAN carry pathogens.

Answer 5

True

Question 6

T/F The higher the temperature the greater the water vapor content is of the delivered gas.

Answer 6

True

Question 7

The majors types of Humidifiers are: 4

Answer 7

1) Bubble humidifiers
2) Passover humidifiers
3) Moisture Exchangers (artificial nose, heat moisture exchangers HME/HCH )
4) Wick

Question 8

3 Types of Heat Moisture Exchanger HME (passive humidifiers) are:

Answer 8

1) Simple (only 50% efficient)
2) Hygroscopic (up to 70% efficient)
3) Hydrophobic (>= 70% efficient and filters microbes)

Question 9

Indications and Contraindications for Heat Moisture Exchanger HME: (both 3)

Answer 9

Indications..

1) Mechanical ventilation
2) Spontaneously breathing patients with an artificial airway
3) Transport

Contraindications..

1) Copious amounts of sputum
2) Patients receiving very small or very tidal breathing
3) High minute ventilation

Question 10

Common problems with humidification system: 3

Answer 10

1) Condensation
2) Cross contamination
3) Ensuring proper conditioning of the inspired gas

Question 11

What are the 4 types of unheated bubble humidifiers?

Answer 11

1) Aerway
2) Aquapak
3) McGaw
4) Travenol

Question 12

Poor humidification result in: 6

Answer 12

1) Heat and water loss
2) Thicker mucus
3) Damaged cilia
4) Damaged cells
5) Mucus plugging
6) Atelecasis due to V/Q mismatch, decreased compliance.

Question 13

Common problems with bland aerosol therapy: 6

Answer 13

1) cross contamination and infection
2) environmental safety
3) inadequate mist production
4) over hydration
5) bronchospasm
6) noise

Question 14

What is ISB?

Answer 14

isothermic saturation boundary

- the point normally 5 cm below the carina. The temperature is 37 degrees C and it has 100% relative humidity.

Question 15

What happens above the isothermic saturation boundary ISB?

Answer 15

Above isothermic saturation boundary, the temperature and humidity decrease during inspiration and increase during exhalation.

Question 16

What happens below the isothermic saturation boundary ISB?

Answer 16

Below the isothermic saturation boundary, the temperature and relative humidity remain constant (BTPS).
BTPS stands for Body Temperature (37°C), ambient Pressure and gas Saturated with water vapor

Question 17

What are the indications for humidification therapy? 4

Answer 17

1) Humidifying dry medical gases/flows greater than 4 l/min,
2) overcoming humidity deficit
created when upper airway is bypassed
3) managing hypothermia and
4) treating bronchospasm caused by cold air.

Question 18

What are the clinical signs/symptoms of inadequate airway humidification? 7

Answer 18

1) Atelectasis,
2) Dry nonproductive cough,
3) increased airway resistance,
4) increased incidence of infection,
5) increased work of breathing,
6) patient complaint of substernal pain and airway dryness, and
7) thick dehydrated secretions.