I started freaking since it doesn't seem beneficial to have a reduced cardiac output. Am I giving myself a low cardiac output, a la congestive heart failure, for 8 hours each night by using CPAP? I did some digging into the research papers and articles, and indeed, I found that:Higher pressures are good at maintaining open airways but can depress cardiac output Prof. Brian Glenville
So is seems that CPAP causes a reduction in cardiac output for non-CHF patients and an increase in cardiac output for CHF patients. What is lacking with these kind of statements is the interrelationship with differing health conditions and if a reduction of left-ventricular preload really happens in you (someone with no, or mild, or severe CHF) and to what degree, if it is at all harmful if it does occur, and if it is harmful, is the detriment overcome by the benefits of treating a breathing disorder. This interplay of cardiac response and breathing response, and any other biological response, to CPAP seems to be not well understood. I have not found information to substantiate any harmful effects of the apparent reduction in left-ventricular preload in otherwise non-CHF patients.CPAP decreases cardiac output by reducing left-ventricular preload without affecting afterload. In patients with congestive heart failure (CHF), however, because cardiac output is relatively insensitive to changes in preload (but very sensitive to changes in afterload), CPAP-induced reductions in left-ventricular transmural pressure can augment cardiac output (http://www.sleepreviewmag.com/issues/ar ... -01_03.asp) (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1765907/).
There are many CPAP benefits for CHF patients that don't have OSA: reducing LV (left-ventricular) transmural pressure gradient and LV end diastolic volume, assisting inspiratory muscles, increasing end expiratory lung volume, and impeding venous return. None of these have anything to do with OSA. Additional health benefits are provided by treating the OSA as well.
I suspect that reduced left-ventricular preload is a non-issue for most of us. But, the Newswire Today article includes the next statement:
What was the POC clinical trial for, to determine the therapeutic results for treating ventilation issues providing a bridge between full ventilation and self-ventilation related to post-op open heart surgery? Without more, we have no clue if the trial was for OSA therapy or for the former.Eran Lavi – Discover Medical's CEO explains that in a recent POC clinical trial, it showed that Discover Medical Device’s revolutionary mask – the SomnuSeal require less air pressure than traditional masks in order to achieve the same therapeutic results. In general the reduction of required air pressure was reduced from 8.8±2.4 H2O to 6.4±1.2 H2O.
While for cardiac patients without CHF in post-op cardiac ICU may be at a critical stage that any reduction of left-ventricular preload might be detrimental, it may be of no consequence to us daily users. I would wager to guess that most patients undergoing open heart surgery has some degree of CHF (and probably everyone over the age of 30), and therefore has a lower response to a reduction of left-ventricular preload and would benefit from the increased pressure.
Maybe the title of the article should be:
Frankly, the reduction in air pressure reported seems to be in the noise of daily fluctuation needs anyway similar to what my APAP is doing to me.______ Mask Will Help Cardiac Patients Without CHF But May Be Detrimental to Those with CHF
Question: Has any doctor ever warned you that a side effect of CPAP therapy is reduced cardiac output? If so, how did the doctor weigh the cons of reduced cardiac output with the pros of overcoming OSA?
It seems to me that they are grasping at anything to market differentiate their stick-in-your-mouth "mask" product. The computer generated design on the website looks like it would shoot a flat jet of air down your throat possibly producing a gag reflex. Maybe works if you are in cardiac intensive care and knocked out.
Just my opinion and observation, not a thorough tech review. I welcome discussion and to learn where I am going wrong with my analysis.
Eran Lavi – Discover Medical's CEO explains that in a recent POC clinical trial, it showed that Discover Medical Device’s revolutionary mask – the SomnuSeal require less air pressure than traditional masks in order to achieve the same therapeutic results. In general the reduction of required air pressure was reduced from 8.8±2.4 H2O to 6.4±1.2 H2O.
Prof. Brian Glenville (former head of Department of Cardiothoracic Surgery at the Hadassah University Hospital in Ein-Kerem, Jerusalem) further explains:
CPAP is often used as a weaning strategy in patients following open heart surgery. These patients do not need full ventilation but they are not ready to transition to self ventilation with an enriched oxygen mask or nasal speculae. CPAP is an ideal intermediate method to bridge that gap. However, the problems associated with its use are principally twofold. On the one side, the pressure needed by straps to force a perfect seal with the mask, is often poorly tolerated. This is even more pronounced if the patient is confused e.g. from hypoxaemia. The second issue is with the pressure of CPAP itself. Higher pressures are good at maintaining open airways but can depress cardiac output. In the postoperative cardiac patient, cardiac output may be impaired and small amounts of CPAP may be poorly tolerated by the heart. The SomnuSeal mask is designed to address both of these issues. The mask fits well without the need for straps to be tightened to unpleasant levels, merely to hold position. Secondly, the mask has been shown to operate at lower CPAP levels and allow cardiac output to be preserved. In short, the SomnuSeal mask is an ideal choice for delivering CPAP in the postoperative cardiac patient.
