ABSTRACT
Introduction: IL-6 has been correlated as a prognostic biomarker for worsening sepsis and COVID-19 as well as positive fluid balance for duration of mechanical ventilation [1, 2]. Method(s): We performed a retrospective cohort study to analyze the correlation between high levels of serum IL-6 and positive fluid balances in the first 24 h of ICU arrival with mechanical ventilation days. We included adult patient records of critical COVID-19 during 2020 from the High Specialty Regional Hospital Bicentenario 2010, all patients were intubated, received treatment according to guidelines inforced in that time. We obtained mean and standard deviation for continuous variables and frequencies for categorical variables, calculated Kolmogorov-Smirnov for non-parametric test and Spearman correlation, OR for severe hypoxemia, RRT. Result(s): We analyzed 102 patient records, 72% were male, mean age 54.8 years (SD 19.4), tracheostomy was performed in 8.8% of cases, mean APACHE II 16.7 (SD 8.4), values of inflammatory markers were C-reactive protein 108 mg/dl (SD 95), IL-6 118 pg/ml (SD 240), mean paO2/FiO2 was 150 mmHg (SD 82), 93% were on vasopressors, fluid balance mean was 1542 ml (SD 839), severe hypoxemia was present on 62.7% (P/F below 150 mmHg), prono was used in 47.1%, with an overall mortality occurred in 69%. We found no correlation between serum IL-6 levels and positive fluid balance with mechanical ventilation days and outcomes (rs -0.11 p = 0.23, Fig. 1). Elevated serum IL-6 + positive fluid balance at 24 h ICU arrival was associated with severe hypoxemia (OR 2.82, CI 95% 1.14-6.97, x2 p = 0.022), OR for discharge was non-significant (0.48 CI 0.19-1.20 p = 0.11), RRT (1.09 CI 95% 0.27-4.37, p = 0.9). Conclusion(s): In our study no correlation was found between serum IL-6 levels, positive fluid balance and mechanical ventilation days, but there was a significant association with severe hypoxemia.