Therapy, Mystery and Anxiety
It occurred to me that some patients will experience anxiety when a change occurs in their mode of therapy. For example, a relatively new patient (3 or so months into therapy) has struggled with fixed or auto CPAP and has recently begun therapy using a bilevel CPAP machine, and the new therapy has been like a brand new obstacle to overcome.
Without diminishing the very real challenge of CPAP therapy and how serious the anxiety can be, I wonder if I can throw some words down here in an attempt to alleviate, possibly, some of the anxiety and frustration associated with the change in modes and/or beginning of therapy, whether it be from fixed or auto CPAP to bilevel CPAP or even to advanced bilevel CPAP such as spontaneous/timed (S/T) machines and adaptive servo ventilator machines (ASV).
Some very well written posts with explanations about nomenclature and all of the abbreviations (cpap, vpap, bpap, asv, xpap…) exist on the forum and my worry for new folks and those transitioning to new modes of therapy is that there may be some mystique and rightfully acquired confusion about all the different ways to obtain the same results. Afterall, we are on the same path to the same goal; a good night's rest night after night.
So, in the beginning, we had single pressure (fixed) CPAP therapy that delivers a single pressure all night long. Often referred to as just CPAP. A breakthrough for people suffering from inconsistent and broken breathing while they slept (apnea). These machines are used when a patient experiences obstructive apnea and do not exhibit signs of central apnea, periodic breathing, or complex apnea (a mixture of every apnea).
Often times, and for various reasons, a single pressure is not the best means of therapy. A machine that delivers two different pressures is required for patient comfort or the enhanced ventilation of a patient. Bilevel CPAP therapy delivers two distinct pressures. One pressure for inhalation and a lower pressure for exhalation. The machine is called BiPAP (Philips-Respironics) or VPAP (Resmed), xPAP and BPAP. These terms are used interchangeably to describe bilevel (two pressure) CPAP therapy. It is arguable that Resmed auto CPAP machines that use expiratory pressure relief (EPR), in fact, are bilevel CPAP machines, because EPR uses two distinct pressures for inhale and exhale up to 3 cmH2O of pressure difference. For the purposes of this writing, I should note that the term bilevel applies to the machines that can deliver >3 cmH2O pressure differences between inhale and exhale pressures. A bilevel machine is still a CPAP machine, as it delivers a continuous pressure to the airway to prevent apnea. CPAP is continuous positive airway pressure. Bilevel CPAP is used to treat obstructive apnea and hypopnea. These machines are helpful for people with other pulmonary conditions such as COPD because of the difference in inhale and exhale pressure (pressure support) is used to alleviate respiratory effort.
We have the technology now for automatically adjusting machines to deliver the correct pressures on demand. By setting a range of pressures, we don't have to breathe against a fixed pressure all night long which may not need to be high all the time. An Auto CPAP is a machine that adjusts pressure when it senses a higher or lower pressure is required to keep an airway open. We start at a lower pressure and when the machine detects that the airway needs more pressure, it automatically raises pressure until the airway opens up. After a period of time without airway obstruction, the machine will begin to lower pressure for the comfort of the patient. This automatic change greatly increases the comfort level of the patient and is very effective at assuring that the correct pressure is being delivered when it is needed. Commonly referred to as APAP, autoPAP, auto, and auto CPAP, it is still a CPAP machine, it just has the capability of automatically adjusting pressure. Auto CPAP machines are used to treat obstructive apnea and hypopnea.
The combination of bilevel with automatic functions is called automatic bilevel CPAP. Essentially, a bilevel CPAP machine that automatically adjusts the exhale pressure and inhale pressure, and sometimes the difference between the two pressures. These machines are commonly referred to as auto bilevel machines, auto BiPAP, auto Vpap, Vauto. Once again, these are still CPAP machines that have different settings configurations and capabilities. These machines are prescribed to patients with the need of a bilevel CPAP machine and the flexibility of automatically adjusting pressures.
The capabilities of bilevel CPAP are further enhanced with advanced bilevel CPAP machines. These machines are referred to as bilevel S/T, BiPAP S/T, VPAP S/T, ASV, autoSV or bilevel with a backup rate. These high tech devices are for patients who experience unresolved central apnea or periodic breathing that requires the machine to initiate a breath when the patient will not on their own (spontaneously) or to stabilize breathing patterns into a uniform and natural flow of inhalation and exhalation. Specifically, the advanced bilevel CPAP machines will raise pressure to coax a patient into breathing and help to deliver a volume of air on a timed basis, whereas a patient may go for a period of time without breathing and without obstruction (central apnea). By the way, central apnea gets its name stemming from the central nervous system (brain and periphery) versus obstructive apnea which occurs via a physical blockage of the airway (relaxation of the muscle associated with keeping the airway open in a lot of cases).
I would like to reiterate that the purpose of this article is to hopefully expose some of the mystery of the various forms of therapy we all endure. That, in the light of this information, anyone that is worried about the new therapy they are receiving or starting all over again, will have a less mysterious approach to staying with therapy. I have only briefly skimmed the surface of the technology of these machines and have explained very little about the details and workings of these machines because I sometimes wonder if I take for granted that everyone knows the basics of operation, and for that, I apologize.
In summary, these machines in all their various forms and types and behaviors are basically CPAP machines. In all the hype that may be perceived about one machine type or mode, we are still getting CPAP therapy in one way or the other. Although all the machines will feel different in pressure and behavior, and some take more getting used to, its still CPAP therapy. For fresh eyes on the matter of CPAP therapy, there is a lot to learn, and for long time users, there is much more to learn. All the information can be very overwhelming and difficult to follow but getting down to the basics, it’s all just CPAP therapy.
I certainly don't want those struggling to think I, or anyone one on this forum, do not take your struggles seriously and everyone is sympathetic to your needs and truly wishes for a good night's rest for you. Hopefully, my perspective and explanation will ease some anxiety. In the end, we all are after a perfect 8 hours of sleep each and every night with days full of energy and well being.