Abstract: Clinical Study Rapid initiation of nasal saline irrigation to reduce severity in high-risk COVID+ outpatients Ear, Nose & Throat Journal 2022, Vol. 0(0) 1–10 © The Author(s) 2022 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/01455613221123737 journals.sagepub.com/home/ear Amy L Baxter, MD1 , Kyle R Schwartz, MPH2, Ryan W Johnson, MPH, MA3, Ann-Marie Kuchinski, PhD1, Kevin M Swartout, PhD4, Arni S R Srinivasa Rao, PhD5,6, Robert W Gibson, PhD, FAOTA1, Erica Cherian, MD3, Taylor Giller, BA, BS3 , Houlton Boomer, BA1, Matthew Lyon, MD1, and Richard Schwartz, MD1  Abstract Objective: To determine whether initiating saline nasal irrigation after COVID-19 diagnosis reduces hospitalization and death in highrisk outpatients compared with observational controls, and if irrigant composition impacts severity. Methods: Participants 55 and older were enrolled within 24 hours of a + PCR COVID-19 test between September 24 and December 21, 2020. Among 826 screened, 79 participants were enrolled and randomly assigned to add 2.5 mL povidone-iodine 10% or 2.5 mL sodium bicarbonate to 240 mL of isotonic nasal irrigation twice daily for 14 days. The primary outcome was hospitalization or death from COVID-19 within 28 days of enrollment by daily self-report confirmed with phone calls and hospital records, compared to the CDC Surveillance Dataset covering the same time. Secondary outcomes compared symptom resolution by irrigant additive. Results: Seventy-nine high-risk participants were enrolled (mean [SD] age, 64 [8] years; 36 [46%] women; 71% Non-Hispanic White), with mean BMI 30.3. Analyzed by intention-to-treat, by day 28, COVID-19 symptoms resulted in one ED visit and no hospitalizations in 42 irrigating with alkalinization, one hospitalization of 37 in the povidone-iodine group, (1.27%) and no deaths. Of nearly three million CDC cases, 9.47% were known to be hospitalized, with an additional 1.5% mortality in those without hospitalization data. Age, sex, and percentage with pre-existing conditions did not significantly differ by exact binomial test from the CDC dataset, while reported race and hospitalization rate did. The total risk of hospitalization or death (11%) was 8.57 times that of enrolled nasal irrigation participants (SE = 2.74; P = .006). Sixty-two participants completed daily surveys (78%), averaging 1.8 irrigations/day. Eleven reported irrigation-related complaints and four discontinued use. Symptom resolution was more likely for those reporting twice daily irrigation (X2 = 8.728, P = .0031) regardless of additive. Conclusion: SARS-CoV-2+ participants initiating nasal irrigation were over 8 times less likely to be hospitalized than the national rate. Keywords COVID-19, coronavirus, SARS-COV-2, nasal lavage, povidone-iodine 1 Department of Emergency Medicine, Augusta University, Augusta, GA, USA Edinburgh Napier University, Edinburgh, UK 3 Medical College of Georgia, Augusta University, Augusta, GA, USA 4 Department of Psychology, Georgia State University, Atlanta, GA, USA 5 Laboratory for Theory and Mathematical Modeling, Department of MedicineDivision of Infectious Diseases, Medical College of Georgia, Augusta University, Augusta, GA, USA 6 Department of Mathematics, Augusta University, Augusta, GA, USA