Can anyone tell me (or point me towards an explanation of ) the difference between a BiPap machine and a ventilator? Is there a clear dividing line between them?

Is it that ventilators provide fixed volume? If so, does that make the Respironics AVAPS a ventilator or a BiPap? (Their website says "BiPAP®AVAPS™ is Respironics' newest noninvasive ventilator" ).

Is there something else that makes a ventilator a ventilator?

For bureaucratic reasons the answers to these questions have suddenly become very important.

I'm a run of the mill cpap user and understand the operation of cpaps and basic Bipaps but not fancier Bipaps and not ventilators.

Thanks,

Midnightowl

Isn't a ventilator for people who don't breathe at all on their own, and may often be unconscious? A bipap can help trigger breathing to an extent if you have centrals, but I think you're still breathing, even if you need a nudge on occasion to do it. This may be too simple, but do you mind saying what the specific issues in question that were raised for you financially?

MidnightOwl wrote:Can anyone tell me (or point me towards an explanation of ) the difference between a BiPap machine and a ventilator?

Well, let's find some definitions that can help. Here's a definitions for a ventilator:

http://www.answers.com/topic/mechanical-ventilation

Where I quote:

Definition

Mechanical ventilation is the use of a mechanical device (machine) to inflate and deflate the lungs.

Purpose

Mechanical ventilation provides the force needed to deliver air to the lungs in a patient whose own ventilatory abilities are diminished or lost.

Description

Breathing requires the movement of air into and out of the lungs. This is normally accomplished by the diaphragm and chest muscles. A variety of medical conditions can impair the ability of these muscles to accomplish this task, including:

• muscular dystrophies
• motor neuron disease, including ALS
• damage to the brain's respiratory centers
• polio
• myasthenia gravis
• myopathies affecting the respiratory muscles
• scoliosis

Mechanical ventilation may also be used when the airway is obstructed, especially at night in sleep apnea.

Though an xPAP unit can be termed a ventilator, it is typically only referred to as a Positive Airway Pressure device (hence "xPAP"). The difference is that most of these units do not deliver so much pressure that it will truly inflate the lungs.

A BiPAP unit is short for a Bi-Level Positive Airway Pressure unit. Most BiPAP units only deliver in increased pressure when your body starts to inhale. Otherwise, they provide the exhalation pressure (a lower pressure value) to decrease the pressure against which you must breathe when you exhale.

Some BiPAP units include a Spontaneous/Timed (S/T) feature. That is, they will either provide the inhalation pressure either when you inhale or after a certain amount of time is reached. This can help remind the body to inhale.

The next level of machine is a BiPAP AutoSV unit (or AdaptSV, depending on the manufacturer). While this unit does not have enough "power" to inflate or deflate the lungs, it tracks the breathing pattern of the patient and helps regulate the breathing. This brand of BiPAP unit is generally considered to be a noninvasive ventilator, since it addresses much more serious problems with the regulation of breathing.

Finally, from my understanding as I read this board and material from Respironics, the AVAPS unit does have enough pressure to help inflate and deflate the lungs. It is designed to help patients with seriously compromised breathing system. It definitely is considered to be a noninvasive ventilator.

So, while even a CPAP unit might be called a ventilator, typically only a unit that will help to mechanically inflate and deflate the lungs is considered a ventilator. But that line can become a bit grey. However, most people and professionals do not refer to the garden variety BiPAP unit as a ventilator.

Hope that helps.

The lines are somewhat blurred, since any machine that delivers two pressures is, in a sense, doing part of the breathing work. But home machines for treating sleep-disorderd breathing are not the same machines as, for example, those designed to be used in hospitals to help patients who need to be on a ventilator. So depending on the context of the discussion, I would tend to define the difference according to whether or not a particular machine was designed for treating sleep disorders at home. If it was, then calling that machine a ventilator outside the context of a discussion on sleep-disordered breathing could easily be misleading and lead to misunderstandings, I believe.

Any BiLevel machine that has a backup rate and alrams is classified as a ventilator. These BiLevel machines CAN infact be used to ventilate a patient non-invasively.


AKCPAPGUY

Oh yes! You just reminded me of a recent story where EMT's picked up a patient in cardiac arrest, but the regular defibrillator they normally carried in the ambulance was not working for some reason. The patient, however, had a Cpap machine at home and the EMT's used it at high pressure to take the patient to the hospital, and said it may well have saved his life.

I'm not sure how a CPAP took the place of a defibrillator, but I guess whatever kept him alive to get to the hospital.


AKCPAPGUY

My VPAP Auto has no alarm or backup rate, but it sure makes me feel ventilated. I don't think a hospital doc would be very happy if he told an RT he wanted a patient on a ventilator and later found a cute little home machine hooked to a Swift LT the next day, though.

This wording from ResMed may be helpful:

Backup rate, S/T and T Modes (VPAP ST only)
For the treatment of neuromuscular and restrictive thoracic
diseases, VPAP ST provides a programmable backup
rate in S/T and T modes. Now even your noninvasive
ventilation patients can benefi t from Easy-Breathe quiet
performance and a sleek, travel-friendly package

http://www.resmed.com/us/assets/documents/product/vpap_s/product_brochure/1012690_vpap-s--vpap-st--vpap-auto-25_product-brochure_amer_eng.pdf

So if a person has a VPAP S/T and only uses it in S mode, is he using a ventilator?

All seems kinda blurry to me as a nonmedical guy.

Some thoughts ...

One easy way to think of what makes a ventilator different is it (as previously mentioned) has a timed mode and can deliever breath-out & breath-in pressures.
A Timed Bilevel can be set up to do this. My old PB330 is called a Ventilator in all its manuals.

In the classic sense a hospital ventilator as distinct from a home style ventilator, will typically be a 'volume ventilator' vs a 'pressure ventilator'. But some ventilator machines can be set to operate in many different modes & combinations of modes.

Volume ventilation is when a specific volume of air is delivered (i.e. keeps pushing the air & pressure until the user has taken the dialed up volume).
Pressure ventilation is when the machine delivers a different pressure (as most Bilevels we use do).

The Respironics AVAPS employs a combination of both types of ventilation (pressure & volume).

DSM

Julie wrote:Oh yes! You just reminded me of a recent story where EMT's picked up a patient in cardiac arrest, but the regular defibrillator they normally carried in the ambulance was not working for some reason. The patient, however, had a Cpap machine at home and the EMT's used it at high pressure to take the patient to the hospital, and said it may well have saved his life.

CPAP's are finding increasing use in emergency situations not because they are ventilators, that is, not because they are capable of inducing air flow in the lungs in a person who is not able to move air on their own (CPAP pressures are too low to do that reliably)

but rather because CPAP is able to increase blood oxygenation even without the administration of supplemental oxygen.

Oxygen transport across the alveoli into the blood is strictly a matter of passive diffusion. Oxygen concentration, or more precisely, oxygen partial pressure, is higher in the lungs than it is in the bloodstream, and therefore oxygen moves into the blood. With the addition of CPAP, while the oxygen concentration in the lungs is not changed, the partial pressure of the oxygen is increased, which increases the diffusion of oxygen into the blood.

Clever gadget.

Interesting. Based on this, it would seem that all PAP machines, even the ones delivering constant pressure, could be referred to as ventilators:

"Although continuous positive airway pressure is not a true ventilation mode, it is often referred to as a form of noninvasive ventilation. This technique delivers constant positive pressure during both inspiration and expiration, either by use of a flow generator with a high pressure gas source or by use of a portable compressor. Continuous positive airway pressure can only be used if the patient is breathing spontaneously because it cannot support ventilation in the absence of a respiratory drive. The physiologic effects of continuous positive airway pressure include augmentation of cardiac output and oxygen delivery, improved functional residual capacity and respiratory mechanics, reduced effort for breathing and decreased left ventricular afterload. In patients with left-sided heart failure, continuous positive airway pressure improves the shunt fraction and reduces the inspiratory work of breathing. In chronic obstructive pulmonary disease, continuous positive airway pressure reduces the work of breathing by counterbalancing the inspiratory threshold load imposed by the intrinsic positive end-expiratory pressure created by airflow obstruction.

"Pressure support ventilation allows the patient to control inspiratory and expiratory times while providing a set pressure. In conjunction with patient effort and respiratory mechanics, the set pressure determines the inspiratory flow and tidal volume. The combination of inspiratory assistance with expiratory positive airway pressure (also known as bilevel ventilation or bilevel positive airway pressure) is thought to reduce the work of breathing and to alleviate respiratory distress more effectively than continuous positive airway pressure alone."--http://www.cmaj.ca/cgi/content/full/177/10/1211

Things be gettin' blurrier and blurrier.

BiPAP = Bilevel Positive Airway Pressure (Non-invasive ventilation)
Ventilator= Mechanical delivery of breaths using various modes (IMV,Assist Control, Pressure Support, CPAP, APRV, Volume Ventilation) The list goes on and on depending upon the manufacturer and trademarked software incorporated into the device. Ventilators may provide invasive ventilation through endotracheal or tracheostomy tubes thereby controlling the patient's inspiratory efforts (Control). Ventilators are considered more technologically sophisticated than non-invasive ventilators (BiPAP) though BiPAP is a trademarked name of a company and not necessarily a generic term. The correct term is NIV (Non-invasive Ventilator).