Restricted accessResearch articleFirst published online 2019-03
The Effect of an Expiratory Resistance Mask with Dead Space on Sleep,Acute Mountain Sickness,Cognition,and Ventilatory Acclimatization in Normobaric Hypoxia
We examined the hypothesis that an expiratory resistance mask containing a small amount of dead space (ER/DS) would reduce the apnea–hypopnea index (AHI) during sleep, attenuate the severity of acute mountain sickness (AMS), and offset decrements in cognitive function compared with a sham mask. In a double-blinded, randomized, sham-controlled, crossover design, 19 volunteers were exposed to two nights of normobaric hypoxia (FIO2= 0.125), using a ER/DS mask (3.5 mm restrictive expiratory orifice; 125 mL DS volume) and sham mask (zero-flow resistance; 50 mL DS volume). Cognitive function, AMS, and ventilatory acclimatization were assessed before and after the 12-hour normobaric hypoxia exposure. Polysomnography was conducted during sleep. AHI was reduced using the ER/DS sleep mask compared with the sham (30.1 ± 23.9 events·hr−1 vs. 58.9 ± 34.4 events·hr−1, respectively; p = 0.01). Likewise, oxygen desaturation index and headache severity were reduced (both p < 0.05). There were also benefits on limiting the hypoxia-induced reductions in select measures of reaction speed and attention (p < 0.05). Our study indicates that a simple noninvasive and portable ER/DS mask resulted in reductions (49%) in AHI, and reduced headache severity and aspects of cognitive decline. The field applications of this ER/DS mask should be investigated before recommendations can be made to support its benefit for travel to high altitude.
Get full access to this article
View all access options for this article.
References
1.
AinsliePN, LucasSJE, and BurgessKR. (2013). Breathing and sleep at high altitude. Respir Physiol Neurobiol, 188:233–256.
2.
BaileyDM, EvansKA, JamesPE, McenenyJ, YoungIS, FallL, GutowskiM, KewleyE, McCordJM, MøllerK, and AinsliePN. (2009). Altered free radical metabolism in acute mountain sickness: Implications for dynamic cerebral autoregulation and blood-brain barrier function. J Physiol, 587:73–85.
3.
BennettCL, PetrosTV, JohnsonM, and FerraroFR. (2008). Individual differences in the influence of time of day on executive functions. Am J Psychol. 349–361.
4.
BurgessKR, JohnsonP, EdwardsN, and CooperJ. (2004). Acute mountain sickness is associated with sleep desaturation at high altitude. Respirology (Carlton, Vic.), 9:485–492.
5.
BurgessKR, LucasS, BurgessKME, DonnellyJ, BasnyatR, TyumkoMM, DayT, SmithK, LewisN, and AinsliePN. (2018). Increasing cerebral blood flow reduces the severity of central sleep apnea. J Appl Physiol, 124:1341–1348.
6.
BurgessKR, LucasSJE, ShepherdK, DawsonA, SwartM, ThomasKN, LucasRA, DonnellyJ, PeeblesKC, BasnyatR, and AinsliePN. (2013). Worsening of central sleep apnea at high altitude—a role for cerebrovascular function. J Appl Physiol, 114:1021–1028.
7.
BurgessKR, LucasSJE, ShepherdK, DawsonA, SwartM, ThomasKN, LucasRA, DonnellyJ, PeeblesKC, BasnyatR, and AinsliePN. (2014). Influence of cerebral blood flow on central sleep apnea at high altitude. Sleep, 37:1679–1687.
8.
CaldwellHG, CoombsGB, TymkoMM, Nowak-FlückD, and AinsliePN. (2018). Severity-dependent influence of isocapnic hypoxia on reaction time is independent of neurovascular coupling. Physiol Behav, 188:262–269.
9.
ColeWR, ArrieuxJP, SchwabK, IvinsBJ, QashuFM, and LewisSC. (2013). Test-retest reliability of four computerized neurocognitive assessment tools in an active duty military population. Arch Clin Neuropsychol, 28:732–742.
10.
DaviesCR, and HarringtonJJ. (2016). Impact of obstructive sleep apnea on neurocognitive function and impact of continuous positive air pressure. Sleep Med Clin, 11:287–298.
11.
DempseyJA. (2005). Crossing the apnoeic threshold: Causes and consequences. Exp Physiol, 90:13–24.
12.
DempseyJA, and SkatrudJB. (1986). A sleep-induced apneic threshold and its consequences. Am Rev Respir Dis, 133:1163–1170.
13.
DempseyJA, VeaseySC, MorganBJ, and O'DonnellCP. (2010). Pathophysiology of sleep apnea. Physiol Rev, 90:797–798.
14.
EichenbergerU, WeissE, RiemannD, OelzO, and BartschP. (1996). Nocturnal periodic breathing and the development of acute high altitude illness. Am J Respir Critic Care Med, 154:1748–1754.
15.
GerardA, McElroyM, TaylorM, GrantI, PowellF, HolverdaS, SentseN, and WestJ. (2000). Six percent oxygen enrichment of room air at simulated 5000 m altitude improves neuropsychological function. High Alt Med Biol, 1:51–61.
16.
HackettPH, ReevesJT, ReevesCD, GroverRF, and RennieD. 1980. Control of breathing in Sherpas at low and high altitude. J Appl Physiol, 49:374–379.
17.
HackettPH, RoachRC, HarrisonGL, SchoeneRB, and MillsWJJ. 1987. Respiratory stimulants and sleep periodic breathing at high altitude. Almitrine versus acetazolamide. Am Rev Respir Dis, 135:896–898.
18.
HeinzerR, SaugyJJ, RuppT, TobbackN, FaissR, BourdillonN, RubioJH, and MilletGP. 2016. Comparison of sleep disorders between real and simulated 3450-m altitude. Sleep, 39:1517–1523.
19.
HoilandRL, HoweCA, CoombsGB, and AinsliePN. (2018). Ventilatory and cerebrovascular regulation and integration at high-altitude. Clin Auton Res, 28:423–435.
20.
HonigmanB, TheisMK, Koziol-McLainJ, RoachR, YipR, HoustonC, and MooreLG. (1993). Acute mountain sickness in a general tourist population at moderate altitudes. Ann Intern Med, 118:587–592.
21.
JohnsMW. (1991). A new method for measuring daytime sleepiness: The Epworth Sleepiness Scale. Sleep, 14:540–545.
22.
JohnsonPL, PopaDA, PriskGK, EdwardsN, and SullivanCE. (2010). Non-invasive positive pressure ventilation during sleep at 3800 m: Relationship to acute mountain sickness and sleeping oxyhaemoglobin saturation. Respirology, 15:277–282.
23.
KernerNA, RooseSP, PeltonGH, CiarleglioA, ScodesJ, LentzC, SneedJR, and DevanandDP. (2017). Association of Obstructive Sleep Apnea with Episodic Memory and Cerebral Microvascular Pathology: A Preliminary Study. Am J Geriatr Psychiatry, 25:316–325.
24.
LahiriS, MaretK, and SherpaMG. 1983. Dependence of high altitude sleep apnea on ventilatory sensitivity to hypoxia. Respir Physiol, 52:281–301.
25.
LaunayJ-C, NespoulosO, Guinet-LebretonA, BesnardY, and SavoureyG. (2004). Prevention of acute mountain sickness by low positive end-expiratory pressure in field conditions. Scand J Work Environ Health, 30:322–326.
26.
LipmanGS, KanaanNC, PhillipsC, PomeranzD, CainP, FontesK, HigbeeB, MeyerC, ShaheenM, WentworthS, and WalshD. (2015). Study looking at end expiratory pressure for altitude illness decrease (SLEEP-AID). High Alt Med Biol, 16:154–161.
27.
LiuHM, ChiangIJ, KuoKN, LiouCM, and ChenC. (2017). The effect of acetazolamide on sleep apnea at high altitude: A systematic review and meta-analysis. Ther Adv Respir Dis, 11:20–29.
28.
LovisA, De RiedmattenM, GreinerD, LeccisoG, AndriesD, ScherrerU, WellmanA, SartoriC, and HeinzerR. (2012). Effect of added dead space on sleep disordered breathing at high altitude. Sleep Med, 13:663–667.
29.
LuksAM, McIntoshSE, GrissomCK, AuerbachPS, RodwayGW, SchoeneRB, ZafrenK, and Hackett PH; Wilderness MedicalSociety. (2014). Wilderness Medical Society practice guidelines for the prevention and treatment of acute altitude illness: 2014 update. Wilderness Environ Med, 25(4 Suppl):S4–S14.
30.
LuksAM, Van MelickH, BatarseRR, PowellFL, GrantI, and WestJB. (1998). Room oxygen enrichment improves sleep and subsequent day-time performance at high altitude. Respir Physiol, 113:247–258.
31.
LundqvistC, BenthJ, GrandeR, AasethK, and RussellM. (2009). A Vertical VAS is a valid instrument for monitoring headache pain intensity. Cephalalgia, 29:1034–1041.
32.
McFarlandRA. (1937). Psycho-physiological studies at high altitudes in the Andes. I. The effect of rapid ascents by aeroplane and train. J Comp Psychol, 23:191–225.
33.
MoragaF, IvanL, MoralesA, SozaD, and NoackJ. (2018). The effect of oxygen enrichment on cardiorespiratory and neuropsychological responses in workers with chronic intermittent exposure to high altitude (ALMA, 5050 m). Front Physiol, 9:187.
34.
NespouletH, RuppT, BachassonD, TamisierR, WuyamB, LévyP, and VergesS. (2013). Positive expiratory pressure improves oxygenation in healthy subjects exposed to hypoxia. PLoS One, 8:e85219.
35.
NespouletH, WuyamB, TamisierR, SaunierC, MonneretD, RemyJ, ChabreO, PépinJL, and LévyP. 2012. Altitude illness is related to low hypoxic chemoresponse and low oxygenation during sleep. Eur Respir J, 40:673–680.
36.
Nussbaumer-OchsnerY, UrsprungJ, SiebenmannC, MaggioriniM, and BlochKE. (2012). Effect of short-term acclimatization to high altitude on sleep and nocturnal breathing. Sleep, 35:419–423.
37.
OrrJ, HeinrichE, DjokicM, GilbertsonD, DeyoungP, Anza-RamirezC, VillafuerteFC, PowellFL, MalhotraA, and SimonsonT. (2018). Adaptive servoventilation as treatment for central sleep apnea due to high-altitude periodic breathing in nonacclimatized healthy individuals. High Alt Med Biol, 19:178–184.
38.
PatzDS, PatzMD, and HackettPH. (2013). Dead Space Mask Eliminates Central Apnea at Altitude. High Alt Med Biol, 14:168–174.
39.
PavlicekV, SchirloC, NebelA, RegardM, KollerEA, and BruggerP. (2005). Cognitive and emotional processing at high altitude. Aviat Space Environ Med, 76:28–33.
40.
RahnH, and OrtisA. (1949). Man's respiratory response during and after acclimatization to high altitude. Am J Physiol, 157:445–462.
41.
RoachRC, BartschP, HackettPH, and OelzO. (1993). The Lake Louise acute mountain sickness scoring system. In: Hypoxia and Molecular Medicine. JR Sutton, CS Houston, and G. Coates, eds. Queen City Press, Burlington, VT. pp. 272–274.
42.
SampsonJB, CymermanA, BurseRL, MaherJT, and RockPB. (1983). Procedures for the measurement of acute mountain sickness. Aviat Space Environ Med, 54:1063–1073.
43.
SavoureyG, CateriniR, LaunayJC, GuinetA, BesnardY, HanniquetAM, and BittelJ. (1998). Positive end expiratory pressure as a method for preventing acute mountain sickness. Eur J Appl Physiol Occup Physiol, 77:32–36.
44.
SchoeneRB. (2008). Illnesses at high altitude. Chest, 134:402–416.
45.
SchoeneRB, RoachRC, HackettPH, HarrisonG, and MillsWJ. (1985). High altitude pulmonary edema and exercise at 4,400 meters on Mount McKinley. Effect of expiratory positive airway pressure. Chest, 87:330–333.
46.
SeveringhausJ. (1979). Simple, accurate equations for human blood O2 dissociation computations. J Appl Physiol, 46:599–602.
47.
TymkoMM, AinsliePN, MacLeodDB, WillieCK, and FosterGE. (2015). End tidal-to-arterial CO2 and O2 gas gradients at low- and high-altitude during dynamic end-tidal forcing. Am J Physiol Regul Integr Comp Physiol, 308:R895–R906.
48.
Virués-OrtegaJ, Buela-CasalG, GarridoE, and AlcázarB. (2004). Neuropsychological functioning associated with high-altitude exposure. Neuropsychol Rev, 14:197–224.
49.
WayneKS. (1976). End-Expiratory Pressure (PEEP) Ventilation: A Review of Mechanisms and Actions. JAMA, 236:1394–1396.
50.
ZhangJ, LiuH, YanX, and WengX. (2011). Minimal effects on human memory following long-term living at moderate altitude. High Alt Med Biol, 12:37–43.
