Researchers quantify burden of COVID-19 on mechanical ventilation usage

The total number of invasive mechanical ventilation days for patients in critical care increased by 38% during April 2020 to December 2020, according to a study published in Annals of the American Thoracic Society.

Further, the median monthly rate of invasive mechanical ventilation (IMV) use per 1,000 patients increased by 15% during those 9 months of the pandemic, according to researchers.

“This study expands current understanding by quantifying the immediate and cumulative impact of COVID-19 on IMV during the first 9 months of the pandemic in the United States,” Justin M. Rucci, MD, of the Boston University School of Medicine, and colleagues wrote. “The relative increases in IMV-days and rates of IMV that we quantified can inform estimations of ventilator and staffing resources that may be necessary to care for patients during future pandemics.”

Rucci and colleagues used the Premier Healthcare Database to analyze 1,199,986 adult ICU or step-down unit (SDU) admissions across 423 U.S. hospitals between 2016 and 2020 to determine IMV changes during the COVID-19 pandemic.

Total number of IMV-days per month served as the study’s primary outcome, with the monthly rate of IMV per 1,000 ICU and SDU patients combined as the secondary outcome.

Researchers assessed changes in IMV trends that occurred due to the pandemic through interrupted time series (ITS) with segmented regression.

Of the total cohort, 1,010,837 admissions to the ICU or SDU occurred before the pandemic and 189,149 occurred during the pandemic.

Researchers observed a higher number of median monthly IMV-days during vs. prior the pandemic (121,296 days vs. 90,439 days).

Through the ITS model, researchers found a nonstatistically significant increase of 12,471 IMV-days (95% CI, –10,210 to 35,151) per month close to the beginning of the pandemic compared with the stable rate of 38 IMV-days (95% CI, –73 to 149) per month prior to the pandemic.

Additionally, compared with expected values recorded before the pandemic, there was a 38% increase (305,610 IMV-days) in IMV-days from April 2020 to December 2020, with the months of April to May and October to December contributing 62% of these excess IMV-days.

When evaluating monthly rate of IMV use, researchers observed a slight increase during the pandemic (159 per 1,000 ICU/SDU patients) compared with before (152 per 1,000 ICU/SDU patients).

Before the pandemic, there was a decrease in this rate (–0.3 per 1,000 ICU/SDU patients; 95% CI, –0.4 to –0.2), but the start of the pandemic sparked an increase in the median monthly rate of IMV use (79 per 1,000 ICU/SDU patients; 95% CI, 64-94).

Similar to the trends observed for IMV-days, researchers found a 15% increase (183 per 1,000 ICU/SDU patients) in the median monthly rate of IMV use from April 2020 to December 2020, and the months of April to May and October to December contributed 78% of that increase.

“We demonstrated that the number of IMV-days increased disproportionately to the rate of ICU + SDU patients who received IMV, suggesting that ventilator availability during a pandemic may be further strained by the increased duration of IMV,” Rucci and colleagues wrote. “This increase in the duration of IMV highlights that pandemic planning should expand beyond just increasing ventilator capacity.”

The researchers also recommended additional study of strategies to optimize IMV delivery, such as sedation use to enhance ventilator liberation, determining optimal length of tracheostomy, involving palliative care and utilizing long-term acute care facilities.