The fundamentals of vitality include food, water, air, shelter, and sleep. Sleep, though often underappreciated, can influence our physical and mental health, complex and easily impacted by outside factors. Living at a high altitude may be wonderful but what is gained in beauty and adventure, is compromised with reduced quality sleep. With increasing elevation comes more nighttime awakenings, brief arousals, nocturnal hypoxemia, and periodic breathing. Light sleep increases and slow-wave and REM sleep decrease.
The current gold standard for diagnosis of suspected sleep disorders includes polysomnography: seven or more streams of data at a hospital or sleep center. The SleepImage System allows for more flexibility with children, adolescents, and adults. Currently, Dr. Chris Ebert-Santos of Ebert Family Clinic in Frisco, Colorado, USA (9000′) is using this technology primarily to assess some of the most common forms of Sleep Breathing Disorders and secondly, to analyze the percentage of oxygen desaturation of her patients while in their homes.
The SleepImage System measures several variables that construct a summary for each individual. Sleep quality is generated using Sleep Quality Index (SQI) biomarkers. Pathology markers measure sleep duration, efficiency, and latency. Central Sleep Apnea (CSA) and Obstructive Sleep Apnea (OSA) are assessed together as Sleep Apnea Hypoxia Index (sAHI). Periodic and fragmented sleep pathology are reported and can be used to assess disease management long-term.
Recently, the clinic analyzed Patient X’s sleeping patterns without and with supplemental oxygen. The theory: adding a steady flow of oxygen to the nightly sleep regimen reduced the total amount of time desaturating and severity of sleep breathing disorders. On the night preceding treatment, Patient X experienced an SQI of 17 (expected >55) and efficiency at 95% (expected >85%) for overall sleep quality. Sleep opportunity demonstrated a 0h:02m latency (expected <30m), and duration of 5h:47m (expected 7-9h); sAHI was marked as severe for both 4% and 3% desaturation with values at 34 and 61, respectively (severe= >30.0 in adults). Fragmented sleep was at 55% (expected <15%) and periodicity at 22% (expected <2%). Lastly, Patient X spent 25% of his night’s sleep under 90% SpO2, 18% under 88% Spo2, and 4% under 80% SpO2. Ideally, a healthy night’s sleep should aim to remain above 90% SpO2 for the majority of the time in bed.
When oxygen supplementation was introduced, improvements were observed. Sleep quality showed a slight change, SQI increased to 31 (previously 17, expected >55), and efficiency decreased to 87% (previously 95%; expected >85%) while remaining at a target value. Sleep opportunity showed a slight increase during latency to 0h:12m while remaining within the expected value of <30mins; duration jumped to 8h:14m but that could be attributed to an early bedtime. Fragmented sleep remained in the severe range but decreased by 5%; periodicity improved to 0%, removing it from both the severe and moderate range. The most notable improvement was observed with sAHI, both the 3% and 4% desaturation categories improved to the moderate range with values of 9 and 14, respectively. Time under 90% SpO2 also improved to only 4% throughout the night and 0% below 88% SpO2.
Since data is collected while patients sleep, skewed results from the placebo effect can be reduced or eliminated. Increased duration could be attributed to longer time in bed, as mentioned above, and should be examined more in-depth longitudinally. Latency for sleep increased with oxygen treatment but that could be attributed to discomfort from the nasal cannula or greater tiredness one day over the other. Similarly, latency should be examined longitudinally.
The results seen with this patient are common in our population. Many people report they slept significantly better their first night on oxygen. Many patients studied on and off oxygen show the same dramatic decrease in their sleep apnea index. The gold standard for treating sleep apnea involves a mask to increase the pressure in the airway and prevent the collapse and narrowing that occurs during relaxation and sleep. Does the supplemental 2 liters per minute of oxygen cause enough increased airway pressure to prevent airway narrowing? Supplemental oxygen would not be considered for an intervention or treatment in other locations where sleep studies are conducted because they are not usually showing significant hypoxia. Does the improvement in oxygen, even if it is the difference between oxygen saturations in the high 80’s and low 90’s increasing to the mid 90’s affect the balance of oxygen and carbon dioxide in a way that changes the incidence of apnea and drive to breathe during sleep?
Long-term, this easy-to-use SleepImage System can assess sleep disorders across all age groups and contribute to long-term management for many people living at altitude. Oxygen, a simple intervention that is widely available and relatively inexpensive, requiring no special visits to fit and adjust, has the potential to improve symptoms and sleep greatly.
References
- Introduction to SleepImage https://sleepimage.com/wp-content/uploads/Introduction-to-SleepImage.pdf
- Diagnosis and treatment of obstructive sleep apnea in adult https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5714700/
- Sleep and Breathing at High Altitude https://pubmed.ncbi.nlm.nih.gov/11898114/#:~:text=Sleep%20at%20high%20altitude%2 0is,REM%20sleep%20have%20been%20demonstrated.measure
Ashley Cevallos is a second-year Physician Assistant student at Red Rocks Community College in Arvada, CO. She received her undergraduate degree from University of Maryland, Baltimore County. Before PA school, she worked as a vestibular technician and research coordinator for Johns Hopkins department of Otolaryngology. She was born in Ecuador and raised in Maryland. In her free time, she enjoys hiking, yoga, discovering new plants/animals and picnics.
