Randomized controlled trial comparing flexible and continuous positive airway pressure delivery: effects on compliance, objective and subjective sleepiness and vigilance.
OBJECTIVE
Positive airway pressure (PAP) treatment for obstructive sleep apnea (OSA) can be limited by suboptimal compliance. C-Flex technology (Philips Respironics, PA, USA) reduces pressure during expiration, aiming to improve comfort and therefore compliance. This may be of particular relevance to patients requiring high pressures. Many studies thus far have suffered from design limitations and small sample sizes. This study aimed to compare compliance with C-Flex and CPAP, as well as analyzing objective and subjective sleepiness and vigilance.


METHODS
Three-month, double-blinded, parallel-arm randomized controlled trial.


METHODS
A university-based sleep laboratory.


METHODS
76 consecutive patients with severe OSA (mean +/- SD AHI 60.2 +/- 32.9 events/hour, ESS 13.6 +/- 4.5/24, BMI 35.6 +/- 7.8 kg/m2), without significant cardiac, respiratory, psychiatric, or sleep comorbidities.


METHODS
Patients were randomized to C-Flex (dip level 2) or CPAP.


RESULTS
Patients underwent titration with C-Flex/CPAP (mean pressure 11.6 cm H2O). Modified maintenance of wakefulness tests (mod-MWT), psychomotor vigilance tasks (PVT) and questionnaires were administered at baseline and after one and 3 months. Median compliance was 5.51 and 5.89 h/night in the C-Flex and CPAP groups respectively (P = 0.82). There were no significant differences between groups in terms of PVT reaction time, subjective sleepiness, sleep quality, health-related quality of life, or treatment comfort. There was no significant difference between the groups regarding the change in mod-MWT sleep latency values.


CONCLUSIONS
In patients with severe OSA both CPAP and C-Flex resulted in substantial improvements in sleepiness, vigilance, and quality of life. The use of C-Flex did not result in greater compliance, and neither treatment appeared superior.
Bakker
Jessie
J
WellSleep Sleep Investigation Centre, Department of Medicine, University of Otago, Wellington, New Zealand. jessie.bakker@otago.ac.nz
Campbell
Angela
A
Neill
Alister
A
D000328:Adult; D000368:Aged; D001143:Arousal; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data*; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data*; D011597:Psychomotor Performance; D011788:Quality of Life; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D011795:Surveys and Questionnaires
J Am Coll Cardiol. 2008 Aug 19;52(8):686-717
18702977
N Engl J Med. 1993 Apr 29;328(17):1230-5
8464434
Chest. 1999 Aug;116(2):403-8
10453869
Pneumologie. 2007 Nov;61(11):692-5
17661239
Sleep. 2009 Jul;32(7):949-56
19639758
Chest. 2006 Oct;130(4):1018-24
17035433
Sleep. 1991 Dec;14(6):540-5
1798888
Chest. 2006 Jun;129(6):1459-67
16778262
Psychophysiology. 1973 Jul;10(4):431-6
4719486
Sleep Med. 2002 Jul;3(4):329-34
14592195
Ann N Y Acad Sci. 2008;1129:305-22
18591490
Sleep Med Rev. 2003 Feb;7(1):81-99
12586532
Chest. 2005 Oct;128(4):2151-8
16236868
Psychiatry Res. 1989 May;28(2):193-213
2748771
Sleep. 2006 Dec;29(12):1521-30
17252882
Proc Am Thorac Soc. 2008 Feb 15;5(2):173-8
18250209
Am J Respir Crit Care Med. 2001 Feb;163(2):344-8
11179104
Hypertension. 2000 Jan;35(1 Pt 1):144-7
10642289
Lancet. 1999 Jun 19;353(9170):2100-5
10382693
Eur Respir J. 2003 Aug;22(2):258-62
12952257
Sleep. 2007 Jun;30(6):711-9
17580592
Sleep Med. 2007 Dec;9(1):42-53
17825611
Sleep. 2000 Jun 15;23 Suppl 4:S150-3
10893091
Sleep Breath. 2009 Mar;13(1):73-7
18551327
Sleep. 2005 Jan;28(1):123-44
15700728
Am J Respir Crit Care Med. 2001 Aug 15;164(4):608-13
11520724
Sleep Breath. 2008 Nov;12(4):393-6
18516638
Thorax. 2006 Dec;61(12):1083-90
16928705
Sleep. 2006 Apr;29(4):545-52
16676788
Sleep. 1997 Oct;20(10):835-43
9415942
Lancet. 2002 Mar 16;359(9310):966-70
11918933
Sleep. 1992 Apr;15(2):173-84
11032543
Am J Respir Crit Care Med. 1999 Feb;159(2):461-7
9927358
J Hypertens. 2006 Oct;24(10):2091-9
16957571
Sleep. 1999 Aug 1;22(5):667-89
10450601
Chest. 2005 Jun;127(6):2085-93
15947324
Lancet. 2002 Feb 9;359(9305):515-9
11853818
Ann Intern Med. 2001 Jun 5;134(11):1015-23
11388814
Lancet. 1981 Apr 18;1(8225):862-5
6112294
Psychiatry Clin Neurosci. 2001 Jun;55(3):305-10
11422885
J Physiol Pharmacol. 2008 Dec;59 Suppl 6:401-6
19218664
Sleep. 2005 Jan;28(1):113-21
15700727
Thorax. 2005 May;60(5):427-32
15860720
Electroencephalogr Clin Neurophysiol. 1997 Nov;103(5):554-62
9402886