Incidence, Characteristics, and Outcomes of Ventilator-associated Events during the COVID-19 Pandemic

Abstract

Rationale: Ventilator-associated event (VAE) surveillance provides an objective means to measure and compare complications that develop during mechanical ventilation by identifying patients with sustained increases in ventilator settings after a period of stable or decreasing ventilator settings. The impact of the coronavirus disease (COVID-19) pandemic on VAE rates and characteristics is unknown. Objectives: To compare the incidence, causes, and outcomes of VAE during the COVID-19 pandemic year versus prepandemic years and among ventilated patients with and without COVID-19. Methods: In this retrospective cohort study of mechanically ventilated adults at four academic and community hospitals in Massachusetts, we compared VAE incidence rates between March 1 and August 31 for each year from 2017 to 2020 (corresponding to the time frame of the pandemic first wave in 2020) and among COVID-19-positive and COVID-19-negative patients in 2020. The medical records of 200 randomly selected patients with VAEs in 2020 (100 with COVID-19 and 100 without COVID-19) were analyzed to compare conditions precipitating VAEs in patients with versus without COVID-19. Results: VAEs per 100 episodes of mechanical ventilation were more common in 2020 than in prior years (11.2 vs. 6.7; P < 0.01) but the rate of VAEs per 1,000 ventilator-days was similar (14.2 vs. 12.7; P = 0.08). VAEs were more frequent in COVID-19-positive patients than in COVID-19-negative patients in 2020 (29.0 vs. 7.1 per 100 ventilator episodes [P < 0.01] and 17.2 vs. 12.2 per 1,000 ventilator-days [P < 0.01]). Compared with patients without COVID-19 with VAEs, patients with COVID-19 and VAEs had similar rates of infection-related ventilator-associated complications, longer median durations of mechanical ventilation (22 vs. 14 d; P < 0.01), and similar in-hospital mortality (30% vs. 38%; P = 0.15). Progressive acute respiratory distress syndrome (ARDS) accounted for 53% of VAEs in patients with COVID-19, whereas it accounted for 14% of VAEs among patients without COVID-19. Conclusions: VAE rates per 100 episodes of mechanical ventilation and per 1,000 ventilator-days were higher among COVID-19-positive patients than among COVID-19-negative patients. Over 50% of VAEs in patients with COVID-19 were caused by progressive ARDS, whereas less than 15% of VAEs in patients without COVID-19 were caused by progressive ARDS. These findings provide insight into the natural history of COVID-19 in ventilated patients and may inform targeted strategies to mitigate complications in this population.

Keywords: COVID-19; SARS-CoV-2; mechanical ventilation; ventilator-associated complication; ventilator-associated event.

Figure 1.

Ventilator-associated event rate per 100 episodes of mechanical ventilation and per 1,000 ventilator-days by month from 2017 to 2020. VAE = ventilator-associated event.

Figure 2.

Clinical events leading to pandemic period ventilator-associated events (VAEs) stratified by (A) COVID-19 status and (B) early versus late VAEs. ARDS = acute respiratory distress syndrome; COVID-19 = coronavirus disease; VAP = ventilator-associated pneumonia.