Outcomes of patients with COVID-19 vary by level of organ support, age

New data from the International Viral Infection and Respiratory Illness Universal Study Registry highlight variation in outcomes of patients with COVID-19 by type and combination of organ support therapy and age.

The results were presented at the Society of Critical Care Medicine’s Critical Care Congress.

Amos Lal, MBBS, MD, fellow in the department of critical care medicine in the division of pulmonary and critical care medicine at Mayo Clinic in Rochester, Minnesota, and colleagues described outcomes of hospitalized patients in the multicenter, international VIRUS registry. The cross-sectional observational study enrolled more than 49,000 patients hospitalized from February to November 2020 at 179 hospitals in 16 countries.

Lal presented data from 20,608 patients with confirmed SARS-CoV-2 infection (54.3% men). Of those, 3,986 were aged 18 to 44 years, 5,300 aged 45 to 60 years, 6,491 aged 60 to 74 years and 4,831 aged 75 years and older. Older patients had more comorbid conditions at baseline, including hypertension (15.9% in 18-44 group vs. 65.9% in 75 and older group), diabetes (15.6% vs. 32.1%, respectively), chronic kidney disease (3.6% vs. 20.4%, respectively) and coronary artery disease (1.2% vs. 22.7%).

Patients were stratified by type of organ support therapy: 15,001 required no support, 5,005 required invasive mechanical ventilation and 602 required vasoactive drugs and/or acute renal replacement therapy with or without invasive mechanical ventilation. Further stratification showed that 1,749 patients required invasive mechanical ventilation only, 2,032 required both invasive mechanical ventilation and vasoactive drugs, 655 required invasive mechanical ventilation, vasoactive drugs and renal replacement therapy, 180 required invasive mechanical ventilation and renal replacement therapy and 389 required extracorporeal membrane oxygenation, according to the data presented.

The primary outcome was hospital mortality based on type of organ support therapy received. The secondary outcomes included discharge home with or without assistance and hospital or ICU length of stay.

Steroid use was 13.7% overall, and use was high among those aged 45 to 60 years (14.9%) and those aged 60 to 74 years (15.3%) and lowest among those aged 18 to 44 years (13.1%) and those aged 75 years and older (10.6%), Lal said.

Researchers observed an increase in hospital length of stay with increased age, from a median of 5 days in the youngest age group and nearly 9 days in the oldest age group.

The percentage of patients discharged home with or without assistance was 68.6% among those aged 18 to 44 years and decreased to 28% among those aged 75 years and older.

Among all patients in the registry 19% died (4.6% aged 18 to 44 years; 34.3% aged 75 years and older).

This mortality trend overlapped with level of organ support therapy patients required, according to the results:

• No organ support therapy: 8.2% (0.7% 18-44 years; 23.6% 75 years and older)
• Invasive mechanical ventilation only: 40.8% (15.5% 18-44 years; 61.3% 75 years and older)
• Invasive mechanical ventilation and vasopressors: 53% (28.9% 18-44 years; 74.3% 75 years and older)
• Invasive mechanical ventilation, vasopressors and renal replacement therapy: 71.6% (50% 18-44 years; 78.3% 75 years and older)
• Any invasive mechanical ventilation: 49.8% (25.4% 18-44 years; 68.1% 75 years and older)
• ECMO: 35% (25.4% 18-44 years; 35.9% 75 years and older

Lal said the researchers observed “significant in-hospital mortality.” They reported 1.69 times higher odds of mortality among patients presenting to a higher-mortality hospital vs. a lower mortality hospital. He noted this inter-hospital mortality variation will be further explored in studies already underway.

The researchers also found that as the requirement for organ support increased, the changes of discharge home with or without support declined in all age groups, but more so for the older age group, Lal said. The percentage of patients discharged to home who received no organ support was 73.5 (93.2% 18-44 years; 40.9% 75 years and older), invasive mechanical ventilation alone was 29.8% (60.3% 18-44 years; 14.3% 75 years and older), invasive mechanical ventilation and vasopressors was 22.2% (47.5% 18-44 years; 7.2% 75 years and older), invasive mechanical ventilation, vasopressors and renal replacement therapy was 8.8% (27.1% 18-44 years; 3.8% 75 years and older), any invasive mechanical ventilation was 24.2% (50.2% 18-44 years; 10.8% 75 years and older) and ECMO was 41.2% (48.1% 18-44 years; 48.7 75 years and older), according to the results.

Length of stay for patients who required organ support therapy did not vary significantly by age, Lal said.

The international VIRUS Registry is a live registry, and more patients are being added at collaborative sites worldwide, Lal said.

These data provide “new important information for the clinician to discuss with the patients and the family [of] patients who come in with acute infection of COVID-19,” Lal said during the virtual presentation. “Based on the organ support therapy that they are requiring, what is the expected outcome?”

The data are also helpful at the hospital and administrative level for resource planning and resource allocation, especially in areas with limited resources, he said.

Reference:

Domecq JP, et al. Crit Care Med. 2021;doi:10.1097/CCM.0000000000004879.