ICU

CPAP: Operation, Principle, Handling, CPAP Mask and Cleaner

CPAP stands for Continuous Positive Airway Pressure. It consists of the humidifier, CPAP mask, and the tubing as its main external components which can be sterilized by another machine known as the CPAP cleaner.

CPAP is a type of non-invasive positive pressure ventilation in which a single positive pressure is applied to the patient and can be changed as per the requirement.

Difference between CPAP and BiPAP

( BiPAP VS CPAP )

CPAP BiPAP
Stands for Continuous Positive Airway Pressure Stands for Bilevel Positive Airway Pressure
It continuously provides a single airway pressure to the patient. However, the set value can be changed as per the requirement of the patient. It continuously provides two airway pressures to the patient. One is during the inspiration, while the other one is during expiration.
It is useful for the treatment of patients with normal breathing problems such as sleep apnea. If the condition of the patient becomes much more complex, then BiPAP is better.
Since a single high positive pressure is applied continuously, expiration might be difficult. Since a lower airway pressure is applied during expiration, breathing becomes much easier.
It is cheaper to purchase It is much more expensive in comparison to the CPAP.

Working Mechanism of CPAP

Block Diagram of CPAP

Image Source: https://www.researchgate.net/figure/The-block-diagram-of-the-experimental-CPAP-setup_fig1_221797667

Atmospheric air goes to the blower of the machine through the filters. The blower compresses the air and sends high-pressure air to the connecting tube. Then the air goes to the patient through the nasal mask.

The pressure sensor senses the air pressure in the connecting tube. This sensed pressure signal goes to the microprocessor. Then, the microprocessor analyzes the variation among the set and obtained pressure value. In case of any variation, it either increases or decreases the voltage signal of the driver motor. This, in turn, controls the speed of the blower. Based on the companies there can be some variations in the above block diagram.

Breathing Cycle Under CPAP

The graph shows that the breathing cycle under CPAP is almost the same as the normal breathing cycle.  Also, CPAP pressure is nearly equal to PEEP pressure.

Operation of CPAP Machine

  • Connect the AC cord to the machine and the power supply
  • Connect connecting tube, mask, and humidification tank (if needed)
  • Turn on the machine
  • Pre-heat the water of the humidifier before use (30 mins earlier)
  • The pressure value can range from 5 to 25 cm H2O. Set the value as per the direction of the doctor.
  • Set Ramp time to 30 or 45 mins (if needed). Ramp time is the time period for the positive pressure to reach the set value. Patients often set the starting pressure to  5 cm H2O.

Drawbacks 

  • Continuous high airflow might cause patients, difficult sleep
  • High air pressure might cause patients, difficult to expire
  • Chance of air leakage from the CPAP masks
  • Dry nose and mouth
  • Headache to some patients

Handling 

  • Use soap water to clean mask and humidification tank
  • Do not use alcohol to clean the CPAP machine. You can use Collins.
  • Always use distilled water in the humidification tank
  • An ultra-fine filter is disposable
  • The film filter is washable (life span: 6 months)
  • Check for any leakage in the tubing system.

CPAP Cleaner

Just by manually washing, you may not be able to clean the mask and the tube completely. Thus for better cleaning, you can use CPAP Cleaner to further clean the CPAP machine.

CPAP Mask

CPAP masks are different types of masks that are used for CPAP treatment. Different manufacturers have manufactured different types of masks. However, we will be talking about some of the most common CPAP masks, in this section.

Types of CPAP Masks

1. Nasal Prongs Mask

Nasal Prong Mask, CPAP Mask
Image Source: https://omnisleep.in/product/airmini-cpap-machine-with-p10-mask-nasal-mask/

This type of mask consists of two prongs that go into the nostrils. They are light and portable to use. There is not much leakage of the air. Patients can sleep comfortably using this mask. They can also talk and eat.

Even though this mask is portable to wear, it is not suitable for mouth breathers. It is only suitable for low airflow. If the set pressure in the machine goes to 15 cm H2O or more, the airflow will obstruct the passage of air through the nostrils. This causes two prongs of the mask to dislocate. Also, the tight attachment of prongs into the nostrils will cause difficulty in breathing out the air. It can also cause a swore nose.

2. Nasal Cradle Mask

CPAP Mask, Nasal Cradle Mask
Image Source: https://www.directhomemedical.com/airfit-n30-nasal-cpap-mask-resmed.html

This is the modified version of the nasal prong mask. Instead of two prongs, there are two cradles in the mask.

The only difference between the nasal prong and nasal cradle mask is that there is a chance of more air leakage via the cradle mask.

3. Nasal Mask

Nasal Mask, CPAP Mask
Image Source: https://www.smartmedicalbuyer.com/products/philips-respironics-true-blue-cpap-nasal-mask

A nasal mask covers the entire nose. It is light and portable to use. In comparison to previously stated masks, this mask is suitable for high airflow as well. It provides a tight seal across the face area. So, the chance of leakage of air is low. A patient can also talk and eat using this mask.

Due to the tight sealing of the mask, there is a high chance of skin irritation and red marks around the nose. It is only suitable for nose breathers.

4. Full Face Mask

Full Face Mask, CPAP Mask
Image Source: https://www.cpapstoreusa.com/product/resmed-airfit-f20-full-face-cpap-bipap-mask-with-headgear/

A full-face mask covers the entire face area. This includes the mouth and nose region. It is suitable for both nose and mouth breathers.

It is bulky and difficult to wear while sleeping. The mask may dislocate while sleeping. There is a high chance of air leakage. The patient cannot talk or eat using this mask. The elastic can cause red marks around the nose and ears.

5. Hybrid Mask

Hybrid Mask, CPAP Mask
Image Source: https://www.cpap-supply.com/Hybrid-CPAP-Mask-p/hyb500.htm

A hybrid mask is the combination of a full face mask and nasal cradles mask/nasal prongs mask.  The features of the hybrid mask are similar to that of the full face mask. The only difference is that there is a reduced chance of air leakage in this mask.

 

 

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