Clinical Characteristics and Predictors of 28-Day Mortality in 352 Critically Ill Patients with COVID-19: A Retrospective Study

J Epidemiol Glob Health. 2021 Mar;11(1):98-104. doi: 10.2991/jegh.k.200928.001. Epub 2020 Oct 3.

Abstract

Background: Since the first COVID-19 patient in Saudi Arabia (March, 2020) more than 338,539 cases and approximately 4996 dead were reported. We present the main characteristics and outcomes of critically ill COVID-19 patients that were admitted in the largest Ministry of Health Intensive Care Unit (ICU) in Saudi Arabia.

Methods: This retrospective study, analyzed routine epidemiologic, clinical, and laboratory data of COVID-19 critically ill patients in King Saud Medical City (KSMC), Riyadh, Saudi Arabia, between March 20, 2020 and May 31, 2020. Severe acute respiratory syndrome coronavirus-2 infection was confirmed by real-time reverse transcriptase polymerase chain reaction assays performed on nasopharyngeal swabs in all enrolled cases. Outcome measures such as 28-days mortality, duration of mechanical ventilation, and ICU length of stay were analyzed.

Results: Three-hundred-and-fifty-two critically ill COVID-19 patients were included in the study. Patients had a mean age of 50.63 ± 13.3 years, 87.2% were males, and 49.4% were active smokers. Upon ICU admission, 56.8% of patients were mechanically ventilated with peripheral oxygen saturation/fraction of inspired oxygen (SpO2/FiO2) ratio of 158 ± 32. No co-infections with other endemic viruses were observed. Duration of mechanical ventilation was 16 (IQR: 8-28) days; ICU length of stay was 18 (IQR: 9-29) days, and 28-day mortality was 32.1%. Multivariate regression analysis showed that old age [Odds Ratio (OR): 1.15, 95% Confidence Intervals (CI): 1.03-1.21], active smoking [OR: 3, 95% CI: 2.51-3.66], pulmonary embolism [OR: 2.91, 95% CI: 2.65-3.36), decreased SpO2/FiO2 ratio [OR: 0.94, 95% CI: 0.91-0.97], and increased lactate [OR: 3.9, 95% CI: 2.4-4.9], and D-dimers [OR: 2.54, 95% CI: 1.57-3.12] were mortality predictors.

Conclusion: Old age, active smoking, pulmonary embolism, decreased SpO2/FiO2 ratio, and increased lactate and D-dimers were predictors of 28-day mortality in critically ill COVID-19 patients.

Keywords: COVID-19; D-dimers; active smoking; intensive care unit; lactate; mortality; pulmonary embolism.

MeSH terms

  • COVID-19 Nucleic Acid Testing / methods
  • COVID-19 Nucleic Acid Testing / statistics & numerical data
  • COVID-19* / blood
  • COVID-19* / mortality
  • COVID-19* / therapy
  • Causality
  • Critical Illness* / mortality
  • Critical Illness* / therapy
  • Female
  • Humans
  • Intensive Care Units / statistics & numerical data*
  • Lactic Acid / blood
  • Length of Stay / statistics & numerical data
  • Male
  • Middle Aged
  • Mortality
  • Oxygen Consumption
  • Pulmonary Embolism* / diagnosis
  • Pulmonary Embolism* / etiology
  • Respiration, Artificial / methods
  • Respiration, Artificial / statistics & numerical data
  • SARS-CoV-2 / isolation & purification
  • Saudi Arabia / epidemiology
  • Sex Factors
  • Smoking / epidemiology*

Substances

  • Lactic Acid