Difference between BiPAP vs CPAP Therapy: Explained

CPAP (Continuous Positive Airway Pressure) and BiPAP (Bilevel Positive Airway Pressure) are both non-invasive ventilation therapies used to treat respiratory disorders, primarily sleep apnea and chronic obstructive pulmonary disease (COPD).

CPAP Basics

A continuous positive airway pressure (CPAP) machine directs pressurized air — usually set between 4 and 20 cm H2O — into a user’s airway National Heart, Lung, and Blood Institute (NHLBI)The NHLBI is the nation’s leader in the prevention and treatment of heart, lung, blood and sleep disorders. This pressure keeps air passages open and ensures the user can breathe properly, allowing them to avoid the pauses in breathing (or apnoea’s) that are the primary symptom of sleep apnoea.

CPAP machines continuously pump air at one pressure setting rather than varying in pressure between the inhale and exhale, which can cause some people to feel as though they cannot exhale properly or that they are choking. Most users adjust to CPAP relatively quickly, while others find BiPAP easier to tolerate.

Unlike BiPAP machines, CPAP machines are available in a range of sizes. The most common type is intended to be used at home and is slightly smaller than a shoebox, while travel versions may be small enough to fit in the palm of your hand. Travel models sometimes have backup batteries for use while camping, and FAA-approved models are available for use on planes.

BiPAP Basics

Bilevel positive airway pressure machines have distinct air pressure settings for inhalation (IPAP) and exhalation (EPAP). The EPAP setting is usually significantly lighter than the IPAP setting, allowing users to breathe more naturally and not feel as though they are fighting against the machine when they exhale. Most BiPAP machines have a range of approximately 4 to 30 cm H2O.

BiPAP machines have up to three settings for the switch between IPAP and EPAP.

• Spontaneous: Spontaneous switching automatically senses the user’s breathing pattern and switches between the two pressure levels when they naturally inhale and exhale. The majority of BiPAP users rely on this setting, and it is standard for BiPAP devices.
• Timed: Timed switching allows users to program how long each IPAP and EPAP phase should last. This ensures users take the correct number of breaths per minute and can function much like a ventilator.
• Spontaneous/timed: This setting is primarily spontaneous, following the user’s natural breathing patterns. On this setting, timed switching turns on when the machine senses that the user has dropped below a set number of breaths per minute.

Additionally, BiPAP machines can be fixed or auto-adjusting.

• Fixed: The IPAP and EPAP settings of a fixed BiPAP machine are pre-set and do not change throughout the night.
• Auto-adjusting: An auto-adjusting BiPAP machine has a range set for both IPAP and EPAP. This allows the machine to adjust automatically throughout the night in response to how the sleeper is breathing.

COMPARING CPAP vs BiPAP

If you are comparing CPAP vs BiPAP to treat your sleep apnea, here are some factors to consider!

• Type of Sleep Apnea: CPAP is typically used to treat most cases of Obstructive Sleep Apnea and may be prescribed to people with mild Central Sleep Apnea (CSA). BiPAP is more likely to be suggested for those with CSA and other serious breathing conditions.
• Portability: There is no ultra-portable BiPAP machine, while there are portable travel CPAP machines.
• Air Pressure: BiPAP machines feature air pressures that go up to 25 cm of H2O, while CPAP stops at 20.
• Cost: CPAP devices tend to be more cost-effective as it is usually cheaper to purchase out of pocket and easier to get approval through insurance.
• Easy to Use: BiPAP machines are usually more complex compared to CPAP. Therefore, a CPAP machine may be easier to use for those who struggle with technology.
• Availability: Because they are so popular, CPAP machines are definitely easier to find, and there are more diverse options and unique features to choose from.

Key Differences:

CPAP:

1. Delivers constant pressure throughout breathing cycle
2. Single pressure setting (e.g., 10 cmH2O)
3. Maintains airway patency during inhalation and exhalation
4. Typically used for obstructive sleep apnea (OSA)

BiPAP:

1. Delivers two different pressure levels:
   • Inspiratory Positive Airway Pressure (IPAP): higher pressure during inhalation
   • Expiratory Positive Airway Pressure (EPAP): lower pressure during exhalation
2. Dual pressure settings (e.g., IPAP 15 cmH2O, EPAP 8 cmH2O)
3. Helps with both inhalation and exhalation
4. Often used for:
   • Central sleep apnea
   • Complex sleep apnea
   • COPD
   • Respiratory failure

Comparison Chart:

Clinical Considerations:

1. Patient tolerance: BiPAP may be more comfortable for patients with difficulty exhaling against constant pressure.
2. Respiratory muscle strength: BiPAP may be beneficial for patients with weakened respiratory muscles.
3. Sleep study results: BiPAP may be recommended for patients with complex sleep apnea or central sleep apnea.

Contraindications:

1. Unstable cardiovascular status
2. Severe respiratory acidosis
3. Recent facial or nasal surgery
4. Trauma or injury to the face or head

Monitoring and Adjustments:

1. Regular follow-up appointments
2. Sleep study adjustments
3. Pressure adjustments
4. Mask fit and comfort evaluations

CPAP Nursing Interventions

• Assess the patient’s respiratory status, vital signs, and need for CPAP therapy. The nurse should also assess the patient’s comfort level and tolerance for the CPAP mask.
• Prepare the equipment to ensure that the CPAP machine is functioning properly and that the appropriate pressure settings have been selected based on the patient’s needs. The nurse should also ensure that the mask or nasal prongs are properly fitted to the patient’s face or nose.
• Administer the therapy, starting by placing the CPAP mask or nasal prongs on the patient’s face or nose, ensuring a secure and comfortable fit. The nurse should then turn on the CPAP machine and adjust the pressure settings as needed to achieve the desired therapeutic effect.
• Monitor the patient’s respiratory status, vital signs, and response to therapy. The nurse should also ensure that the mask or nasal prongs remain properly fitted and that the patient is tolerating the therapy.
• Provide patient education on the purpose of the therapy, how to use and care for the equipment, and how to recognize and report any complications or concerns.
• Document the therapy in the patient’s medical record, including the duration and pressure settings of the therapy, the patient’s respiratory status and response to therapy, and any complications or concerns.

Nursing Considerations when Patient on BiPAP

• Respiratory Distress: BiPAP may be indicated in patients who are experiencing respiratory distress, such as difficulty breathing, shortness of breath, or rapid breathing.
• Oxygenation Issues: BiPAP may be used to improve oxygenation in patients with hypoxemia (low oxygen levels) or hypercapnia (high carbon dioxide levels).
• Respiratory Failure: BiPAP may be used as a non-invasive alternative to mechanical ventilation in patients with respiratory failure.
• Sleep Apnea: BiPAP may be used to treat sleep apnea in patients who cannot tolerate CPAP therapy.
• Post-Operative Care: BiPAP may be used in the post-operative care of patients who have undergone certain types of surgery, such as upper abdominal or thoracic surgery.

REFERENCES

1. Kenzie Dubs – CPAP vs. BiPAP Differences: How To Know if You Need a BiPAP Machine retrieved from https://www.cpap.com/blogs/cpap-therapy/difference-bipap-cpap
2. Jay Summer & Dr. Abhinav Singh, BiPAP vs. CPAP Machines: Breaking Down the Differences retrieved from https://www.sleepfoundation.org/cpap/cpap-vs-bipap
3. Kline, L. R. (2022, April 1). Clinical presentation and diagnosis of obstructive sleep apnea in adults. In N. Collop (Ed.). UpToDate., September 12, 2022, fromhttps://www.uptodate.com/contents/clinical-presentation-and-diagnosis-of-obstructive-sleep-apnea-in-adults
4. Pinto V.L., & Sharma S. (2022, May 2). Continuous positive airway pressure. In StatPearls. StatPearls Publishing., Retrieved September 12, 2022, fromhttps://www.ncbi.nlm.nih.gov/books/NBK482178/
5. Brown, L. K. & Lee, W. (2021, September 17). Titration of positive airway pressure therapy for adults with obstructive sleep apnea. In N. Collop (Ed.). UpToDate., Retrieved September 12, 2022, from https://www.uptodate.com/contents/titration-of-positive-airway-pressure-therapy-for-adults-with-obstructive-sleep-apnea

Stories are the threads that bind us; through them, we understand each other, grow, and heal.

JOHN NOORD

Connect with “Nurses Lab Editorial Team”

I hope you found this information helpful. Do you have any questions or comments? Kindly write in comments section. Subscribe the Blog with your email so you can stay updated on upcoming events and the latest articles.