Full face and pillow masks -> different pressure and AHI count...

[CoyoteV8]

Thanks for the responses, I will try to experience both the F10 and the P10 until I settle with either one...

[1howardg]

I have the ResMed AirCurve 10 VAuto. And in the clinical setup, you need to set the kind of mask you are using, full face, pillows, or nasal. If this is not set to the correct mask, your numbers will be wrong. Check your settings.

[VisitorX]

Hi - These journal abstracts suggest that higher pressures are needed with a full face mask:

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Sleep Med. 2014 Jun;15(6):619-24. doi: 10.1016/j.sleep.2014.01.011. Epub 2014 Feb 8.

A randomised controlled trial on the effect of mask choice on residual respiratory events with continuous positive airway pressure treatment.
Ebben MR1, Narizhnaya M2, Segal AZ3, Barone D4, Krieger AC5.

Abstract
INTRODUCTION:
It has been found that mask style can affect the amount of continuous positive airway pressure (CPAP) required to reduce an apnoea/hyponoea index (AHI) to < 5/h on a titration study. However, it was not previously known whether switching from one CPAP mask style to another post titration could affect the residual AHI with CPAP. The purpose of this study was to investigate the differences in residual AHI with CPAP treatment between oronasal and nasal masks.

METHODS:
Twenty-one subjects (age mean (M)=62.9, body mass index (BMI) M=29.6 kg/m2) were randomised (14 subjects completed the protocol) to undergo an in-laboratory CPAP titration with either a nasal mask or an oronasal mask. Subjects were then assigned this mask for 3weeks of at-home CPAP use with the optimal treatment pressure determined on the laboratory study (CPAP M=8.4 cm of H2O). At the end of this 3-week period, data were collected from the CPAP machine and the subject was given the other mask to use with the same CPAP settings for the next 3weeks at home (if the nasal mask was given initially, the oronasal one was given later and vice versa). On completion of the second 3-week period, data on residual AHI were again collected and compared with the first 3-week period on CPAP.

RESULTS:
A Wilcoxon Signed-Rank Test (two-tailed) revealed that residual AHI with CPAP treatment was significantly higher with the oronasal compared with the nasal mask (z = -3.296, p<0.001). All 14 subjects had a higher residual AHI with the oronasal versus nasal mask, and 50% of the subjects had a residual AHI >10/h in the oronasal mask condition, even though all of these subjects were titrated to an AHI of < 5/h in the laboratory.

CONCLUSION:
A higher residual AHI was seen in all patients with the use of an oronasal mask compared with a nasal mask. Switching to an oronasal mask post titration results in an increase in residual AHI with CPAP treatment, and pressure adjustment may be warranted.

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Crit Care. 2013 Dec 23;17(6):R300. doi: 10.1186/cc13169.

Continuous positive airway pressure and ventilation are more effective with a nasal mask than a full face mask in unconscious subjects: a randomized controlled trial.
Oto J, Li Q, Kimball WR, Wang J, Sabouri AS, Harrell PG, Kacmarek RM, Jiang Y.

Abstract
INTRODUCTION:
Upper airway obstruction (UAO) is a major problem in unconscious subjects, making full face mask ventilation difficult. The mechanism of UAO in unconscious subjects shares many similarities with that of obstructive sleep apnea (OSA), especially the hypotonic upper airway seen during rapid eye movement sleep. Continuous positive airway pressure (CPAP) via nasal mask is more effective at maintaining airway patency than a full face mask in patients with OSA. We hypothesized that CPAP via nasal mask and ventilation (nCPAP) would be more effective than full face mask CPAP and ventilation (FmCPAP) for unconscious subjects, and we tested our hypothesis during induction of general anesthesia for elective surgery.

METHODS:
In total, 73 adult subjects requiring general anesthesia were randomly assigned to one of four groups: nCPAP P0, nCPAP P5, FmCPAP P0, and FmCPAP P5, where P0 and P5 represent positive end-expiratory pressure (PEEP) 0 and 5 cm H2O applied prior to induction. After apnea, ventilation was initiated with pressure control ventilation at a peak inspiratory pressure over PEEP (PIP/PEEP) of 20/0, then 20/5, and finally 20/10 cm H2O, each applied for 1 min. At each pressure setting, expired tidal volume (Vte) was calculated by using a plethysmograph device.

RESULTS:
The rate of effective tidal volume (Vte > estimated anatomical dead space) was higher (87.9% vs. 21.9%; P<0.01) and the median Vte was larger (6.9 vs. 0 mL/kg; P<0.01) with nCPAP than with FmCPAP. Application of CPAP prior to induction of general anesthesia did not affect Vte in either approach (nCPAP pre- vs. post-; 7.9 vs. 5.8 mL/kg, P = 0.07) (FmCPAP pre- vs. post-; 0 vs. 0 mL/kg, P = 0.11).

CONCLUSIONS:
nCPAP produced more effective tidal volume than FmCPAP in unconscious subjects.


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Sleep Med. 2012 Jun;13(6):645-9. doi: 10.1016/j.sleep.2012.02.004. Epub 2012 Apr 13.

The efficacy of three different mask styles on a PAP titration night.
Ebben MR1, Oyegbile T, Pollak CP.

Abstract
BACKGROUND:
This study compared the efficacy of three different masks, nasal pillows, nasal masks and full face (oronasal) masks, during a single night of titration with continuous positive airway pressure (CPAP).

METHODS:
Fifty five subjects that included men (n=33) and women (n=22) were randomly assigned to one of three masks and underwent a routine titration with incremental CPAP applied through the different masks.

RESULTS:
CPAP applied through the nasal pillows and nasal mask was equally effective in treating mild, moderate, and severe sleep apnea. However, CPAP applied through the oronasal mask required a significantly higher pressure compared to nasal masks to treat moderately severe (2.8 cm of H(2)O ± 2.1 SD) and severe (6.0 cm of H(2)O ± 3.2 SD) obstructive sleep apnea.

CONCLUSION:
CPAP applied with either nasal mask was effective in treating mild, moderate, and severe sleep apnea. The oronasal mask required significantly higher pressures in subjects with moderate to severe disease. Therefore, when changing from a nasal to an oronasal mask, a repeat titration is required to ensure effective treatment of sleep apnea, especially in patients with moderate to severe disease.

[PaytonA]

Thanks for the abstracts. Interesting confirmations.

[zonk]

Hi - These journal abstracts suggest that higher pressures are needed with a full face mask:

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How high?
In any case scenario, the Autoset would have taken care of any pressure increases and distinguish between apnea events, whether obstructive or central. It should make no difference whether using full face, nasal, or nasal pillows mask, but you'll need set the machine to the mask type
Full face masks leaks more, large leak and apnea scored while you're awake can make the data unreliable

[AshSF]

Hi - These journal abstracts suggest that higher pressures are needed with a full face mask:

-------------

How high?
In any case scenario, the Autoset would have taken care of any pressure increases and distinguish between apnea events, whether obstructive or central. It should make no difference whether using full face, nasal, or nasal pillows mask, but you'll need set the machine to the mask type
Full face masks leaks more, large leak and apnea scored while you're awake can make the data unreliable

Theoretically, yes. It shouldn't matter with APAP. But some practical limitations are there.

Case in point:
I was doing 14cm as my 90% pressure on F10 FFM. I am comfortable at a straight 8cm with P10 nasal pillows. And my AHI and FL readings are lower than FFM auto.

[GeoffD]

I have the ResMed AirCurve 10 VAuto. And in the clinical setup, you need to set the kind of mask you are using, full face, pillows, or nasal. If this is not set to the correct mask, your numbers will be wrong. Check your settings.

I was going to post this. If you flip between FFM and pillows, make sure you configure the machine appropriately.

I went from a Wisp to P10 pillows and never looked back.

My DME had a hissy fit when I changed settings (after consulting with the nurse practitioner at the sleep center). If you're going to change settings to increase the pressure with a FFM, you might want to give your DME a call to see if they care or not. You can always have the sleep center fax them a new Rx. An A10 has a cellular modem. Your DME might be watching.

[VisitorX]

The last of the three abstracts suggests that for moderately severe apnea (I assume this means an AHI range of 15-30) pressue needed to be 2.8 cm higher on average with a FFM than nasal mask; and that for severe (I assume 30+ AHI) pressure needed to be an average of 6 cm higher with a FFM. That was just in that study, and perhaps the difference between nasal and FFM depend on which mask types, etc., so I don't know if this could be used as a guide. You'd probably need to read the full study to understand whether the numbers could, even in principle, be generalized to others.

In general: Without spending time reading the full articles, I don't know what all this means, though. Does it mean (A) that the mask is actually delivering *higher* pressures to the patient's *airways* or (B) simply that when delivered through a FFM, higher pressures (at the machine) are needed to deliver the *same* pressure to the patient's airways? This could be a crucial issue. If (B) is the case, then it seems to me this difference between nasal and FFM is no big deal. But if (A) is the case, and greater pressure at the airways is needed with a FFM, then you could run into issues of comfort (swalloing air) and, for someone with complex or potentially complex apnea (= "treatment-emergent central sleep apnea"--the induction of central apneas and hypopneas in response to the pressure of CPAP), the higher pressures could induce more centrals and a worse AHI. My guess is that most sleep doctors do not know which of these is the case (most seem rather oblivious, in any case, to the reality that complex sleep apnea is not infrequent).

Without reading the full articles--and perhaps it is not clear there anyway?--I don't know if one could know which, A or B, is the case. My guess (purely a guess) is that what is happening is that when pressure is coming just through the nose (nasal mask) some soft tissue near the oropharyx (the back of the mouth) is being displaced by the pressure *forward*--toward the oral cavity, thus expanding that part of the airway and making it easier for pressure to be transmitted futher down; whereas with the FFM, you have (presuably) equal pressures coming from the "top down" (from the nasal cavity down) and "mouth in" and that, with these pressures being equal, some tissue that with the nasal only is being displaced forward and out of the way (towards the oral cavity) is now more in the path of the airflow, so higher pressures are needed overall to open up the whole oral level.

Even if this last supposition is correct, I'm not sure if the higher pressure would necessarily be bad. That would depend largely on whether the pressure is being transmitted *further down* the airway. That is, I'm not sure that higher pressures *at the level of the oropharynx (the back of the throat at the level of the mouth) is a big deal. But if higher pressures are transmitted further down, and pressurs are higher at the opening of the esophogous (food tube) and also trachea (air tube running down to lungs), then there would likely be additonal air swallowing (via the esophagous) and also higher pressures to the lung (which presumably would induce more centrals for someone with complex apnea).

I don't know the answer to these questions, but they are relevant to think about if you are having trouble with a higher AHI with a FFM.

For AshSF--the person who said he has higher AHIs with the FFM even on autoset: I also am not sure what to make of this. If you were at 14 cm for the 90% level, my understanding (based on something I just saw at a commecial CPAP supplier's website) is that this means that you were at 14 or below 90% of the time. What your *mean* (i.e., average) or median or modal pressures are I don't know, and I don't know how easy that would be to find out. But it seems to me at least possible that one could have a 90% pressure of 14 yet still be at a lower pressure (maybe even the 8 cm you referred to) much of the time. Though I guess it is more likely--again, a guess--that to hit 14 as the 90% pressure, you are probably closer to 14 as the mean, median, and mode, too, so the difference in pressure is real, but not as large as the numbers 8 and 14 might suggest. One question would be: how much higher were your AHIs at the higher pressure? If the difference is sizable, then it makes me wonder if both of the following are true: (1) that higher pressures are actually being transmitted to the airways and (2) that you might have complex sleep apnea, which is made worse by the higher pressures. If (2) is true, then you need to be very careful and aware what your responses are to higher pressures. These are just hypotheses, or speculations, but worth at least pondering.

[Ghost1958]

Same with me. Ffm equals a 5 cm rise min pressure to work as well as nasal.
And since it happens when im awake i know why.
Ffm on exhale with my normal lower nasal pressure the tongue easily falls back shutting down my exhalation. An OA. Happens alot.
Raise the min setting high enough it stops.
If one can keep their mouth shut in the ffm it doesnt happen but a ffm encouages one to open their lips.
When that happens the pressure if too low actually encouages the tongue to fall back and the pressure coming in from the nose cant overcome it unless the pressure is raised.

[VisitorX]

Ghost1958: When you raise the pressure by that 5 cm with the FFM, do you swallow more air?