Frequency of extra pulmonary complications in critically ill COVID-19 patients and their association with inflammatory markers and hypoxia: Retrospective analysis at a tertiary care hospital in Karachi, Pakistan.

Background and Objective: This study aimed to determine the incidence of extra pulmonary complications among critically ill COVID-19 patients requiring invasive mechanical ventilation and association of these complications with various inflammatory markers and degree of hypoxia. Methods: A retrospective cohort study was conducted among 173 adults in Karachi having COVID-19 and were admitted to ICU in a tertiary care private hospital between August 2020 to July 2021. Results: The median age of patients included in the analysis was 61 years (IQR; 16). Acute kidney injury, septic shock, cardiac injury, and electrolytes imbalance were the most frequent extra pulmonary complications with proportion of 65.3% (n=113), 63.6% (n=110), 61.8% (n=107) and 33.5% (n=58). Statistically significant differences in the median serum levels of ferritin were observed among male versus female, critically ill covid patients with and without ICU mortality as well as patients with and without hospital mortality (p-value <0.05). Significantly higher serum levels of d-dimer were noted among patients who developed acute liver injury or NSTEMI, or had ICU stay of > 3 days or received mechanical ventilation for >2 days. Conclusion: Acute kidney injury, septic shock, cardiac injury, and electrolytes imbalance were the most common extra pulmonary complications among mechanically ventilated COVID-19 patients with ARDS. Higher serum d-dimer levels were associated with acute liver injury, NSTEMI, ICU stay longer >3 days and invasive mechanical ventilation >2 days. Higher serum ferritin levels are associated with male sex and serve as an important predictor of ICU as well as hospital mortality.