Congestion and Sinonasal Illness in Outer Space: A Study on the International Space Station

This study aims to characterize quantitative data pertaining to sinonasal symptoms and their related medication use aboard the International Space Station (ISS). A secondary focus involves correlating these findings with mission parameters such as extravehicular activity (EVA) participation and mission duration.

This retrospective cohort study was conducted utilizing data requested from the National Aeronautics and Space Administration (NASA) Lifetime Surveillance of Astronaut Health (LSAH) program.

Of 71 de-identified ISS astronauts beginning with Expedition 1 in the year 2000 through 62 in 2019, there were 754 logged medical events; 60 astronauts reported any type of sinonasal medical event (85%), the most common being general nasal congestion in 53 astronauts (75%). Symptoms were attributed to microgravity-induced fluid shifts in 34 astronauts (57%) while 17 (28%) attributed symptoms to ear clearing and barotrauma. Pseudoephedrine was the most used medication, with 95 recorded uses, followed by oxymetazoline spray at 51. Among the 60 astronauts with sinonasal medical events, the 24 with references to extravehicular activity (EVA) participation in their records had on average, 9.19 more records than those without (95% CI: 2.29-17.06).

Sinonasal symptoms are a prevalent medical concern among astronauts aboard the ISS. The findings suggest that early spaceflight-associated fluid shifts contribute significantly to these symptoms, often requiring medication use. A correlation between EVA participation and a higher number of medical events highlights an occupational risk factor.

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