The effect of atrial fibrillation on the success of mechanical ventilation and mortality in patients with acute respiratory failure before and during the Covid-19 pandemic

Atrial Fibrillation (AF) is the most common arrhythmia detected in the intensive care unit (ICU). It is known that mortality increases with acute respiratory failure, hypoxemia, and existing atrial fibrillation. There is limited data on whether the presence of AF in patients with respiratory failure in the ICU provide an additional increase in mortality during the pandemic period. In our study, it was aimed to compare the effect of AF on mortality in patients with respiratory failure, treated in the ICU before and during the pandemic. Patients and methods Retrospective observational cross-sectional study was conducted in Level 3 ICU of a chest diseases and surgery training and research hospital. The pre-pandemic period was defined as January 2017 - March 2020 and there was 26 Level 3 ICU beds during that period. Patients admitted to the enlarged ICU with 60 beds between March 2020 and December 2022 were assigned to the pandemic period. Patient's demographic characteristics, additional diseases, respiratory support types and duration, APACHE II values, ICU stay days and mortality were recorded from ICU monthly statistical data. Results During the study period, 9966 patients were admitted to the ICU. When all of the patients were evaluated; it was seen that the male gender was less, the average age was higher, and chronic diseases, especially cardiac and kidney diseases, were more common in AF patients (Fig. 1). Pulmonary edema and renal failure as the primary cause of ICU admission were found to be significantly higher in AF positive patients (p < 0.001 for both). While the number of isolated NIV or IMV applications were similar in both groups, the need for both ventilation support consecutively was significantly higher and longer in patients with AF (p < 0.001 and p = 0.029, respectively) (Fig. 2). 3867 (39%) patients before the pandemic and 6099 (61%) patients during the pandemic period were included in the study. It was observed that the presence of AF decreased during the pandemic period (446 (11.5%); 480 (7.9%)). The mortality significantly increased with AF in pandemics (Table 1). Conclusion The observed increase in the duration of MV in patients with AF may be attributed to the potential benefits of positive pressure ventilation in reducing preload. However, further research is necessary to clarify the reasons for the significant increase in AF-related mortality during the pandemic period. It is imperative that these patients receive more thorough and careful follow-up care to improve outcomes.