The Impact of Cigarette Smoking on Clinical Progress of COVID-19 in Hospitalized Patients at Al-Kindey Teaching Hospital, Baghdad, Iraq

Export Objective: Although smoking is a major known risk factor for respiratory disease, the effect of smoking on coronavirus disease 2019 (COVID-19) is to be studied. The aim of this study was to determine the effect of smoking on the clinical progress of patients with COVID-19 infection. Methods: This was a cohort prospective study including 125 who had an infection with SARS-CoV-2, admitted according to WHO guidelines to Al-Kindy Teaching Hospital during the period from 1st April to 1st September 2021. Patients were categorized into three groups according to their smoking status: never-smokers (50 patients), current smokers (50 patients), and ex-smokers (25 patients). Patients were followed-up until they were discharged from the hospital or entered the respiratory care unit (RCU). Results: Out of 125 included patients, 24 patients (19.2%) required RCU admission. Such admission was more common among current smokers (28%) and ex-smokers (24%) compared with nonsmokers (8%), with significant differences. The mean SpO2 in nonsmokers was 93.0%±4.53%, which was significantly higher than that of current smokers (89.26%±5.59%) and ex/smokers (90.12%±4.82%). Two clinical symptoms were significantly associated with smoking. The frequency of shortness of breath and cough in nonsmokers was 64% and 62%, respectively, compared with 82% and 86%, respectively, in current smokers and 92% and 80%, respectively, in ex-smokers with a significant difference, the difference is mainly between the nonsmokers on one side and the current and ex-smokers on the other side while the difference between the current and ex-smokers is not significant. Conclusions: About one-fifth of patients with COVID-19 need for RCU admission regardless of their smoking status. However, the requirement for RCU admission is significantly more common in current and ex-smoker patients compared with nonsmoker. Smoking (whether current or previous) is associated with lower SpO2 and more common need for NRBM and CPAP ventilations.