In hospital settings, the terms “NIV” and “BiPAP” are often used synonymously. However, when patients are being discharged to home care, the exact terminology used by physicians is essential in order to prescribe the precise therapy.

By Bill Pruitt, MBA, RRT, CPFT, AE-C, FAARC

Published: May 24, 2021


As technology advances in the sophistication of medical equipment in the home, as home monitoring to provide reports back to the primary care provider, and as the move toward the “medical home” continues, in-home respiratory support in particular is growing. The medical home allows patients to be cared for at home where in the past this care was only provided in the hospital.1 With the increasing move to handle complex care at home, the right terminology for exactly what is needed becomes very important.

CPAP, BiPAP, or NIV?

Patients with chronic respiratory issues may have support at home provided by Continuous Positive Airway Pressure (CPAP) at the minimum to support oxygenation, or may need more mechanical support during inspiration and will be changed to Bilevel Positive Pressure (BiPAP). This provides the expiratory positive pressure (CPAP) and adds a pressure supported breath to increase tidal volume. Beyond this, some patients will have higher complexity in their health issues due to respiratory disease or comorbid conditions, or have a high risk of quickly digressing into respiratory failure. These patients include those with neuromuscular disease, chest wall deformity, central hypoventilation or obesity hypoventilation, severe obstructive sleep apnea, failure to improve with nasal CPAP, and COPD with severe hypercapnia or nocturnal desaturation. For these patients, CPAP and BiPAP will not provide enough support or may not have appropriate alarms, so noninvasive ventilation (NIV) may be required.2

All three devices are used noninvasively, but BiPAP and NIV will provide more support to the patient by providing pressure supported inspiratory breaths (set as inspiratory positive airway pressure of IPAP) along with an elevated baseline pressure (set as an expiratory positive airway pressure of EPAP). However, in discussing BiPAP or NIV for home use, there are potential problems with the particular discharge orders that may result in the wrong approach being delivered. This article will explore why terminology matters when patients with chronic respiratory issues are discharged to a medical home.

In the acute care setting many patients need ventilatory support to provide some rest for the muscles of ventilation (to “buy time” for recovery or prevent acute respiratory failure) and/or assistance in removing excessive CO2 levels. To initiate this level of support in the hospital a physician may order BiPAP or NIV … and often these terms are synonymous. In published research dealing with acute care these terms are used interchangeably.3

The respiratory therapy staff frequently has a history of dealing with these patients during the admission and are aware of the circumstances and the patient’s particular need for support. Either “BiPAP” or “NIV” orders from the physician will result in a complex device set up to handle the support with the full alarm package, breath-by-breath assessment of tidal volume, assessment of minute ventilation, close monitoring of pressures, back-up settings for hypoventilation or apnea, settings for respiratory rate (frequency), and settings for desired tidal volume and minute ventilation.

In addition, NIV machines (for example the Philips Trilogy Evo) offer a variety of modes including volume control, pressure control, continuous mandatory ventilation (CMV or sometimes referred to as A/C), synchronized intermittent mechanical ventilation (SIMV), pressure support ventilation (PSV), and Average Volume‐Assured Pressure Support–Automated Expiratory positive airway pressure (AVAPS–AE).

On the other hand, if the hospitalized patient has an order for BiPAP due to issues like obstructive sleep apnea (OSA), a less complex machine (not a NIV device) will be initiated to provide BiPAP (for example the Dreamstation). Often the BiPAP machines used in the hospital are the same (or very similar to) devices used in the home for sleep disturbances. Compared to the NIV devices, this device does not incorporate the same monitoring, alarms, back-up settings for apnea, and does not provide as wide a range in modes or settings.

When asked about BiPAP versus NIV in the home, William A Broughton, MD, Professor Medicine, board certified in Pulmonary and Sleep Medicine (Mobile, AL) had this response: “BiPAP in its simplest forms comes in two forms: spontaneous mode (which only executes a pressure change triggered by spontaneous breathing) and spontaneous/timed mode (which executes with spontaneous breathing and at fixed rate if no spontaneous breathing occurs). In COPD, spontaneous mode can be useful. Executing with patient-triggered breaths, it can provide a PSV-like support and augment tidal volume. Tidal volume (TV) can be estimated in the lab in real time or from the compliance.“

“Spontaneous/Timed mode (S/T) is more useful in situations with unstable respiratory drive, like congenital alveolar hypoventilation or central sleep apnea (CSA). Generally, the home models used for BiPAP don’t offer the alarms,” Dr Broughton added. “When alarms and more exacting volume delivery is required, more complex devices like the Trilogy home ventilator are used. These are complex devices that require a background and familiarity to use them expertly. These involve a fixed or variable EPAP, a minimum PSV/IPAP and a maximum PSV/IPAP. TV targets and rates are entered as well.”

However, if the patient is being discharged, the physician needs to use the right terminology for the home. If a physician prescribes “BiPAP,” this can result in the selection of a device that more closely functions like a hospital BiPAP device used for sleep and is not equivalent to what a BiPAP order in the acute care setting might entail (as described above). If the physician prescribes “Home NIV,” this triggers the selection of a device that more closely functions like a hospital NIV device with the alarms, monitoring, the variety of settings and back-up settings comparable to what would be provided in the hospital environment.

Why Is This Terminology Important?

Consider this scenario: a COPD patient is admitted to the hospital for an acute exacerbation and has orders to be placed on BiPAP. The device utilized for this may be a V-60 or another critical care ventilator that can provide BiPAP as a non-invasive option with the intent that complete and timely monitoring, alarms, and settings be initiated. When it’s time to be discharged the physician prescribes BiPAP as had been the case in the admitting orders, with the intent that the full monitoring, alarms, settings, etc, are included. The problem here is that rather than obtaining a NIV device, the COPD patient may receive a device designed for sleep. If the physician wants to ensure an NIV device, they need to prescribe “NIV” rather than “BiPAP” for the home.

Again, why is this important? If there is risk of acute respiratory failure, hypoventilation, or apnea, the home NIV device will sound an immediate alarm where the home BiPAP unit will not. Home BiPAP units may provide information concerning episodes and events (like the apnea-hypopnea index) but these events are not linked to an immediate alarm to alert a caregiver in the home. The reports that show the events are generally gathered after the fact to allow for a review of the patient’s sleep and compliance with the orders over a period of days, weeks, or months.

When asked if this mix up between BiPAP and NIV occur and the wrong thing is prescribed at discharge, Dr Broughton responded: “Of course. That is most common when the final prescription comes from someone unfamiliar with the differences in these devices, say a primary care doctor trying to set up home care on a pulmonologist’s recommendation without fully understanding the situation.”

Other Considerations

A home BiPAP device will not provide a battery back-up for power failures or during travel where a NIV ventilator, like the Philips Trilogy Evo, will run independently from the external electrical course (now with a battery back-up reaching 15 hours). The home BiPAP units are not designed to be taken on a wheelchair or travel with the patient, while the home NIV devices have features that enable traveling or transporting. Devices such as the Trilogy Evo can be mounted onto a roll-stand or a wheelchair, with a mountable, easy-to-use carry bag. The device also “provides noninvasive and invasive ventilator support with added sensitivity for a wide range of adult and pediatric patients. Volume and pressure modes, AVAPS-AE, SpO2 and EtCO2 monitoring and alarms of every parameter allow for adaptable care. Flexibility of circuits allows it to be used in a wide range of patients.” 4-5

[Note: AVAPS-AE stands for Average Volume‐Assured Pressure Support—Automated Expiratory positive airway pressure. This automatically adjusts pressure support (inspiratory positive airway pressure, or IPAP) to maintain the target tidal volume, and automatically adjusts expiratory positive airway pressure (EPAP) to maintain a patent airway.]

Both the home BiPAP and the home NIV devices can administer supplemental oxygen, but the NIV devices will often be more precise in providing a particular set FiO2 while many BiPAP devices will bleed-in oxygen and not be able to provide a clearly defined, set FiO2. Home BiPAP units are designed to help patients overcome issues with OSA and go beyond a CPAP unit by providing the inspiratory boost (pressure support) to increase ventilation, providing support to the ventilatory muscles, increase TV, and decrease PaCO2 by noninvasive means (but they are limited in function compared to a NIV unit).

A device like the Philips Dreamstation has a small footprint and is lightweight to make it more practical in the home and when traveling. The home BiPAP often includes a built-in heated humidifier to improve comfort and compliance with the therapy, and Dreamstation is equipped with three humidification options: fixed, adaptive, and heated tube. The device has a feature called “EZ-Start” that can help patients gradually adapt to their prescribed level of therapy using an innovative pressure acclimation algorithm with automatic, personalized adjustments to PAP pressure over the first 30 days. Connectivity is also incorporated, with standard Bluetooth and optional cellular and Wi-Fi connectivity. Finally, these devices provide summary (and detailed) reports to the provider (usually by a Bluetooth connection) to allow for monitoring of the patient’s sleep habits, events, leak issues, and overall adherence to the therapy ordered.

Conclusion

When it comes to prescribing home NIV vs home BiPAP, terminology matters. Respiratory terminology and abbreviations are confusing (consider the difference between PEEP, CPAP, and EPAP). Moreover, if clear communication and intent have not been conveyed from the physician to the respiratory therapist or home care company at discharge, confusion between an order for “BiPAP” or “NIV” can result.

A Dreamstation is not equivalent to a Triology Evo, and sometimes BiPAP is not equivalent to NIV. Home BiPAP devices can provide a variety of settings and give excellent information to the clinician in summary formats for patient with OSA or other sleep disturbances. The home NIV devices go farther in providing more operational settings, more choices in  modes, immediate alarms to alert the patient or the caregiver, battery back-up for power failures or traveling, and overall flexibility for the more complex home patient. The key here is that the right device/approach needs to be ordered. Terminology really does matter when patients with chronic respiratory issues are discharged to a medical home.

RT

Bill Pruitt, MBA, RRT, CPFT, AE-C, FAARC, is a writer, lecturer, and consultant and recently retired from over 20 years teaching at the University of South Alabama in Cardiorespiratory Care. He also volunteers at the Pulmonary Clinic at Victory Health Partners in Mobile, AL. For more information contact [email protected].


References

  1. From the Agency for Healthcare Research and Quality- The Patient Centered Medical Home:  https://pcmh.ahrq.gov/page/defining-pcmh. Accessed 5/1/2021.
  2. King AC. Long-term home mechanical ventilation in the United States. Respiratory care. 2012 Jun 1; 57(6):921-32.
  3. Osadnik CR, Tee VS, Carson‐Chahhoud KV, Picot J, Wedzicha JA, Smith BJ. Non‐invasive ventilation for the management of acute hypercapnic respiratory failure due to exacerbation of chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews. 2017(7).
  4. From Philips website: https://www.usa.philips.com/healthcare/product/HC0055500/trilogy-evo-portable-hospital-to-home-ventilator. Accessed 5/5/2021.
  5. From Philips website: https://images.philips.com/is/content/PhilipsConsumer/Campaigns/CA20200320_covid/home-ventilation-workshop-trilogy-evo.pdf Accessed 5/6/2021.