Humidification

Question 1

Need humidification because: (3)

Answer 1

• maintain function of cilia
• maintain surfactant properties
• reduce drying of secretions
  
  • atelectasis
  • airway obstruction from drying mucus plugs
  • thickened plugs may become infected

Question 2

The mass of water vapor present in a given volume of air:

Units?

Answer 2

absolute humidity

mg / liter or g / m³

1 m³ = 1000 liters

Question 3

Fully saturated air at 20ºC contains water present in vapor?

Answer 3

17 g / m³

Question 4

Types of HMEs

Answer 4

hydrophobic

hygroscopic

Question 5

Which HME has a small pore membrane?

Answer 5

hydrophobic

Question 6

Which HME is wool, foam coated with moisture retaining chemicals?

Answer 6

hygroscopic

Question 7

Which HME is more efficient at exchanging heat and moisture?

Answer 7

Hygroscopic

Question 8

Which HME has better filtration efficiency when both dry and wet?

Answer 8

hydrophobic

Question 9

Which HME more significantly decreases tidal volumes?

Answer 9

hydrophobic

Question 10

Which HME has significant resistance when wet?

Answer 10

hygroscopic

Question 11

Which HME has a greatly increased resistance when nebulized medications are added?

Answer 11

hygroscopic

Question 12

Which HME is more preferred for our purposes?

Answer 12

hydrophobic

Question 13

HMEs are very good on filtering bacteria but not as well as filtering viruses. True or false?

Answer 13

true

Question 14

Hazards of HMEs

Answer 14

• excessive breathing circuit resistance
• airway obstruction
• aspiration of HME material
• dead space rebreathing
• potential for airway disconnection

Question 15

A bubble-through humidifier with a _____ filter to reduce the size of bubbles and hence increase the surface area for evaporation.

Modern vaporizers use ___ humidifiers.

Answer 15

sintered

wick

Question 16

Gas bubbles through a perforated screen at the bottom of a wide tube, causes a foam of water and gas to pass up the tube. The large surface area of gas exposed to the water ensures that the gas is fully humidified in this type of humidifier.

Answer 16

cascade

Question 17

This type of humidifier is less ideal because such hot elements may cause chemical changes in the anesthetic agents or drugs

Answer 17

heated element

Question 18

Maximum deposition occurs in the alveoli for particles with an aerodynamic diameter of about ____ micron.

Larger particles are predominantly deposited in the large airways. In this size range smaller particles are predominantly _____.

Answer 18

3 mcm

exhaled

Question 19

Relative humidity in the upper trachea is ___%.

Answer 19

77%

Question 20

HME efficiency of humidifying is ___%.

Answer 20

57%

Question 21

Absolute humidity of 100% saturation at 37ºC is _______ g/m³

Answer 21

44 g/m³

Question 22

Absolute humidity in a normal patient is:

Answer 22

23 mg/liter

23 g/m³