TY - JOUR

T1 - The effect of an expiratory resistance mask with dead space on sleep, acute mountain sickness, cognition, and ventilatory acclimatization in normobaric hypoxia

AU - Patrician, Alexander

AU - Tymko, Michael M

AU - Caldwell, Hannah Grace

AU - Howe, Connor A

AU - Coombs, Geoff B

AU - Stone, Rachel

AU - Hamilton, Allison

AU - Hoiland, Ryan L

AU - Ainslie, Philip N

N1 - (Ekstern)

PY - 2019

Y1 - 2019

N2 - 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 (F I O 2 = 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 eventshr -1 vs. 58.9 ± 34.4 eventshr -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.

AB - 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 (F I O 2 = 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 eventshr -1 vs. 58.9 ± 34.4 eventshr -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.

KW - Altitude illness

KW - Cognitive function

KW - Hypoxia

KW - Sleep

UR - http://www.scopus.com/inward/record.url?scp=85063214167&partnerID=8YFLogxK

U2 - 10.1089/ham.2018.0074

DO - 10.1089/ham.2018.0074

M3 - Journal article

C2 - 30720346

AN - SCOPUS:85063214167

VL - 20

SP - 61

EP - 70

JO - High Altitude Medicine and Biology (Print)

JF - High Altitude Medicine and Biology (Print)

SN - 1527-0297

IS - 1

ER -