The Effects of Smoking in Patients in the Intensive Care Unit During the COVID-19 Pandemic

Sisli Etfal Hastan Tip Bul. 2023 Dec 29;57(4):520-525. doi: 10.14744/SEMB.2023.22803. eCollection 2023.

Abstract

Objectives: In this study, we aimed to see the effects of smoking prevalence, the length of stay regarding the usage of cigarettes, and the effects on the mortality of COVID-19 in our Intensive Care Unit (ICU).

Methods: This is a retrospective single-centered study that was done in the ICU on patients with COVID-19 between 16th of March and 16th of May in 2020. The demographic data, comorbidity status, the units they were accepted from, clinical symptoms, respiratory support, prevalence of smoking, length of stay in the ICU, and mortalities of the patients were recorded. There were two groups: Smoker and non-smoker. There were 1100 COVID-19 patients and 150 of these were treated in ICU unit. 95 patient's data were accessed. Statistical analyses were performed with the Scientific Package for the Social Science (version 21.0; SPSS Inc.).

Results: There were 69.4% non-smoker and 35.8% smoker, and 5.3% of the smoker did smoke before (Table 1). The average age of the patients in smoker group was less than nonsmoker. The incidence of chronic obstructive pulmonary disease was higher in smokers (Table 2). The most common symptom was cough and it was 82% in nonsmoker group and 76.5% in smoker group (Table 3). In both groups, respiratory support was provided by İMV (Table 4). There was no relationship between two groups according to age (p=0.044) and gender of patients (p:0.062) (Table 2). The length of ICU stay was 7.6 days for smoking patients in the ICU and 9.3 days for non-users. While the mortality was 52.9% for smokers, it was 39.3% for non-smokers. No statistical correlation was found between smoking status, length of stay in ICU, and survival (Fig. 1). Smoking is blamed among the factors that cause this aggressive process, which can progress to respiratory failure and result in mortality in COVID-19 disease.

Conclusion: Some studies also claim that smoking can be protective. There is still no clarity on this issue. It was concluded that smoking has no effect on the duration of ICU stay and mortality in patients treated in the ICU with respiratory failure due to COVID-19 pneumonia.

Keywords: COVID-19; ICU; mortality; smoking.