Nasal irrigations are thought to reduce the amount of virus from the nasal cavity. The aim of the present study is to evaluate the effect of a hypertonic seawater solution containing algal and herbal natural ingredients (Sinomarin®) on the nasopharyngeal viral load in hospitalized patients with severe COVID-19 pneumonia. The investigators will conducted a prospective, randomized, controlled trial. Patients will be allocated in two groups, the hypertonic seawater group receiving nasal irrigations with a hypertonic seawater solution (Sinomarin®) every 4 hours during a 16-hour interval per day, for two consecutive days, and the control group (no nasal irrigations). Forty-eight hours after the baseline nasopharyngeal swab (and 8 hours after the last wash in the hypertonic seawater group), a second nasopharyngeal swab will be collected for the semiquantitative estimation of the SARS-CoV-2 viral load as determined by cycle threshold (Ct) values.

Investigators will perform a prospective, randomized, controlled study in 56 patients with confirmed COVID-19 pneumonia. All patients will be treated with the standard protocol of care for COVID-19 at the Department of Infectious Diseases and will be randomized into one of two groups with the method of sequentially numbered, opaque, sealed envelopes, the hypertonic seawater group (will receive a hypertonic (2.3% NaCl) seawater solution containing brown algae (Undaria pinnatifida) and blue-green algae (Spirulina platensis) as well as essential oils of Eucalyptus globulus and Mentha spicata, and Thymus vulgaris extract (Sinomarin® Plus Algae Cold & Flu Relief, Gerolymatos International SA, Krioneri, Greece)) and the control group (no treatment). Sinomarin® is a medical device that utilizes continuous flow diffusion. The solution continues to flow as long as the nozzle is pressed, providing efficient cleansing.

At admission, a baseline nasopharyngeal swab will be collected from all patients and placed in a sterile bottle containing virus transport medium (10 ml tube with 3 ml medium, Biobase, Biodustry, Shandong, China) for SARS-CoV-2 nucleic acid detection (zero hour). Patients in the hypertonic seawater group will be given a review on the proper technique for nasal irrigation. Specifically, they will be instructed to blow their nose before irrigation, gently bend their neck forward, tilt their head to one side, and insert the nozzle into the nostril in line with the nasal septum. They will be advised to press firmly on the nozzle to squirt the solution into the nostril and then repeat the process on the other nostril. The patients will also be instructed to spit out any solution coming into their mouth and then return to an upright position to allow the solution to work for a few seconds before blowing their nose gently. After each use, they will be advised to remove the nozzle from the bottle, wash it thoroughly with warm water, and wipe it dry. Thereafter, patients will be given one bottle of 200 ml Sinomarin® and will be instructed to perform nasal irrigation to each nostril every 4 hours for a 16-hour period per day, for two consecutive days.

Forty-eight hours after the baseline nasopharyngeal swab and 8 hours after the last nasal wash, a second nasopharyngeal swab will be collected for viral load measurement. All nasopharyngeal swabs will be collected by a physician blinded to group allocation and will be collected from the same nostril for each patient.

Demographic data including age, sex, nationality, body mass index, smoking status, and date of admission will be collected at baseline. Data on comorbidities, Charlson comorbidity index, disease related symptoms, vaccination status, presenting day of illness since symptom onset, oxygenation status (PaO2/FiO2), and medication administered will also be recorded. Furthermore, outcome and potential adverse effects related to use of hypertonic seawater solution containing algal and herbal natural ingredients will be recorded. All patients will be followed until hospital discharge, ICU admission, or death. Those that will be discharged will be reexamined 14 days after hospital discharge for real-time polymerase chain reaction (RT-PCR). Manual chart review will be used to gather details of the laboratory studies, course, and outcomes.

Inclusion Criteria:

• adult patients hospitalized primarily for COVID-19 pneumonia
• confirmed SARS-CoV2 infection diagnosed through RT-PCR test of nasopharyngeal samples

Exclusion Criteria:

• patients with confirmed SARS-CoV2 infection who were not primarily admitted for COVID-19 pneumonia
• patients with use of intranasal sprays for at least two weeks prior to study enrollment
• sinonasal surgery within 3 months prior to study enrollment
• patients with sinusitis
• inability to perform nasopharyngeal wash
• participation in other trials

All collected individual participant data (IPD)

For one year after the end of the study

Contact study director by e-mail