Clinical and laboratory monitoring
cough
Baseline investigations were performed including full blood count, blood sugar, liver function tests, blood urea, serum creatinine, serum electrolytes, D-dimer, electrocardiogram (ECG), and chest X-ray (CXR). All patients were observed, and vital signs monitored daily (blood pressure, heart rate, temperature, oxygen saturation (SpO2), respiratory rate, NEWS2 score). The change in oxygen saturation to fraction of inspired oxygen ratio (SpO2/FiO2) was measured daily from the start of the trial until day 10 or hospital discharge. The duration of total hospital stay as well as the duration of oxygen use, and the time in days taken to achieve an SpO2 of ≥ 94% on room air were recorded in both groups. Self-reported cough symptom scores were recorded for all in-patients using an ordinal scale until day 10 or until patient discharge, and again at day 28 by follow-up phone call.