CPAP and Humidification Therapy

Peggy Powers, RRTClinical EducationFisher and Paykel Healthcare

Conflict of Interest Disclosure(s)

I do not have any potential conflicts of interest to disclose

MY CPAP GAVE ME A COLD!

Environment

Demographics/ClimateDemographics/Climate

• Desert• Ocean• Altitude• Swamp• Jungle

Background to Humidification

Background to Humidification

What is Humidity?

• Humidity is the amount of water vapor in a gas

• Describing humidity

– Absolute Humidity

– Relative Humidity

• Key humidity concepts

– Maximum Capacity

– Dew point

Absolute Humidity (AH)

30 mg

30 mg/L Absolute Humidity

15 mg/L Absolute Humidity

15 mg

1L

• mgH2O/L is usually referred to as mg/L

Relative Humidity (RH)

30 mg 30 mg

1L

• % = content/capacity x 100

50% Relative Humidity

15 mg 30 mg

100% Relative Humidity

Maximum Capacity

15 mg/L

17 mg/L

19 mg/L

22 mg/L

24 mg/L

27 mg/L

18 ºC 20ºC 22 ºC 24 ºC 26 ºC 28 ºC 30 ºC

30 mg/L

Dew Point

• The temperature at which water vapor begins to condense – Cooling process

• Here, the gas is fully saturated i.e. 100% Relative Humidity

Humidification & the Upper Airway

Anatomy of the Airway

Naso-pharynx

Oro-pharynx

Trachea

•Gross anatomy of the airway

•Three main regions:

• Naso-pharynx

• Oro-pharynx

• Trachea

Inspiration

22 °CRoom Air

7 mg/L, 35% RH

31 °CNaso/Oropharynx30 mg/L, 90% RH

36 °C Trachea

42 mg/L, 100% RH

37 °CIsothermic Saturation

Boundary44 mg/L, 100% RH

Nasal Symptoms

• The airway is a natural heated humidifier

• A constant flow of air delivered via CPAP can dry the nasal mucosa

• Excessive drying of the nasal mucosa increases nasal resistance, thereby increasing nasal discomfort

• Production of mucus is also increased to help humidify the additional air flow

• These factors can induce symptoms such as nasal congestion

Nasal Congestion

• Nasal congestion is a narrowing/blockage of the nasal passages

• It is usually due to membranes lining the nose becoming swollen from inflamed blood vessels.

• Nasal congestion is also known as nasal obstruction, blocked nose, runny nose, or stuffy nose.

Nasal Symptoms

• Nasal symptoms can be alleviated by the use of a humidifier with your CPAP

• When the flow of air is already humidified this reduces the demand on the bodies natural humidification system

Available Humidification Technologies

• No humidity

• Cold pass-over

• Conventional heated humidification

• Heated breathing tube

Humidification Delivery Modes

No Humidification

Effects of No Humidification

Cold Pass-Over Humidification

• An interim treatment for patients who complain of nasal symptoms after initiation of CPAP

• Passing of cold air over water

Effects of Cold Pass-over

• Heating the water filled chamber using a heater plate

• Air passing over the heated water adds moisture and humidifies the delivered air

• Turbulence induced in the chamber helps pick up humidity

Conventional Heated Humidification

Benefits of Conventional Heated Humidification

1. Alleviates reported nasal discomfort

2. Lowers therapy abandonment

3. Improves patient compliance

4. Reduces the incidence of mouth leak

Limitations of Conventional Heated Humidification

• Ambient air temperature

• Condensation

• Disruptive noise leading to fluctuating mask pressure

Condensation – Conventional Humidification

TUBE COOLING = CONDENSATION BUILD UP = PATIENT DISRUPTION

30 oC29 mg/L

20 oC

17 mg/L

Bacon et al, 2000

Condensation

• Copper wire coiled inside breathing tube

• Discounts the effects of changing ambient temperature

• Operates in its own controlled environment

Heated Breathing Tube (HBT)

Conventional vs HBT

Timeline 2hrs

Timeline 2hrs

TUBE COOLING - CONDENSATE FORMS

WARM TUBE: HEAT LOSS + HEAT GAIN = CONSTANT HEAT

Conventional Humidification

Heated Breathing Tube Humidification

18 mg/L

30mg/L

Conventional

HBT

30mg/L

30mg/L

HBT

Clinically Proven for A Better Nights Sleep

• FPH 40 years of experience in humidification technology

• 5 years of global ThermoSmart™ market experience

• Dedicated research program

THE ORIGINAL HEATED BREATHING TUBE

ThermoSmart™

Sensors & algorithms in place of RH and EOH sensors

Proven Clinical Research

START WITH THERMOSMART™

HBT

Clinical Summary

End