Alcohol and Inflight Hypoxia Significantly Worsen Sleep and Oxygen Levels, reveals study

Long-haul flights subject passengers to inadequate oxygen due to a lower pressure in the cabin which can impact sleep. Moreover, alcohol consumption from the list of additives may enhance these effects and lengthen periods characterized by low SpO2 and high heart rates with decreased deep sleep. Low air pressure can decrease the amount of oxygen in blood. It is one of the predominant causes of hypoxia in cabins of flights. This study was conducted to research the combined effect of alcohol consumption and hypobaric hypoxia on sleep patterns, oxygen saturation, and heart rate.

The subjects were two groups of healthy participants followed up during sleep in a normal sleep laboratory or in a hypobaric chamber simulating the reduced air pressure found at an altitude of 2,438 meters (about 8,000 feet). They had a 4-hour sleep opportunity from 00:00 to 04:00 hours and were given alcohol before one of the nights, with a mean blood alcohol concentration of 0.043%. Both nights with and without alcohol were counterbalanced in the order for the groups. The sleep stages were recorded using polysomnography, and oxygen saturation and heart rate were measured all through the night. To ensure a full recovery of participants, two full recovery nights of sleep separated the study conditions.

The study developed a number of important findings on the effects of alcohol and inflight hypoxia on sleep and levels of oxygen:

• Under both conditions combined (alcohol and hypobaric hypoxia), SpO2 fell to a median value during sleep to 85.32% compared to 88.07% without alcohol under the condition of hypobaric hypoxia, whereas in the alcohol-only condition, it was still 94.97%. In the sleep laboratory (ordinary atmospheric pressure), without alcohol, SpO2 reached 95.88 %.

• It increased heart rate to a significant extent in the combined condition with a median of 87.73 bpm as compared with 72.90 bpm in the non-alcohol hypobaric condition, 76.97 bpm in the alcohol condition, and 63.74 bpm in the sleep laboratory without alcohol.

• The time below the clinical threshold of 90% SpO2 median was reached to be 201.18 minutes within the combined condition. For the non-alcohol hypobaric condition, median time below this threshold reached 173.28 minutes. In the sleep laboratory, participants showed no exposure time to the level below 90% SpO2, regardless of alcohol consumption.

• Deep sleep was reduced to 46.50 minutes with the combined condition, as compared to 84.00 minutes while alcohol was used in the sleep laboratory and 67.50 minutes without alcohol.

A combination of alcohol consumption and inflight hypobaric hypoxia severely impairs sleep quality with a further increase in heart rate and prolongs the duration of hypoxemia (SpO2 <90%) in healthy volunteers. It is worth remembering these risks when consuming alcohol for long flights, because the carelessness of alcohol consumption might deteriorate people's overall well-being and recovery while traveling and after arriving at the destination.

Reference:

Trammer, R. A., Rooney, D., Benderoth, S., Wittkowski, M., Wenzel, J., & Elmenhorst, E.-M. (2024). Effects of moderate alcohol consumption and hypobaric hypoxia: implications for passengers’ sleep, oxygen saturation and heart rate on long-haul flights. Thorax, 79(10), 970–978. https://doi.org/10.1136/thorax-2023-220998