Most requiring mechanical ventilation did not survive in study of NY patients

Fewer than a third of patients hospitalized for Covid-19 at New York’s largest hospital system were febrile at presentation, and just 28% were determined to be in need of supplemental oxygen in the largest case series of sequentially hospitalized patients in the U.S. reported to date.

The report on triage, treatment, and outcomes among 5,700 patients admitted to the 12 hospitals in New York City, Long Island, and Westchester County found hypertension, obesity, and diabetes to be the most common comorbidities associated with severe coronavirus requiring hospitalization.

The observational analysis, published online April 22 in JAMA, also found that close to 9-out-of-10 (88.1%) Covid-19 patients who required mechanical ventilation and were not still hospitalized did not survive to discharge.

But researcher Karina Davidson, PhD, of the hospital system Northwell Health, said actual survival among coronavirus patients put on breathing machines is likely to be higher.

In an interview with BreakingMED, Davidson explained that roughly a quarter of the patients are still hospitalized, and the absence of data on those patients may have biased the mortality findings.

The case series also included many patients treated early in the pandemic who presented late in the course of their infection with significant lung impairment, she said.

Davidson highlighted the low incidence of fever at hospital presentation as one of the most clinically significant findings from the case series analysis.

Of the 5,700 patients sequentially hospitalized at Northwell Health centers between March 1 and April 4 (median age, 63 years; range, 0-107 years: 39.7% female), just 30.7% were febrile at triage.

Fever is widely considered a first-line benchmark for suspicion of Covid-19, but the observational finding suggests that a high percentage of patients requiring hospitalization may present without this symptom.

“There are many places simply checking for fever, and that’s it,” she said. “We show that not only can you be infected without fever, you can have severe Covid-19 requiring urgent medical care without fever.”

She added that symptom presentation among patients with Covid-19 is proving to be “diffuse and multiple,” and there is an urgent need to better characterize symptoms that distinguish patients who will develop severe respiratory distress from those who can safely be treated at home.

Measuring oxygen levels using a pulse oximeter may identify silent hypoxia, which is increasingly recognized as an early warning sign of rapid progression to life threatening complications in Covid-19 patients.

But Davidson said it is too soon to know if measuring oxygen levels using a pulse oximeter can reliably identify patients likely to experience severe disease.

“Unfortunately, we don’t yet have a single vital sign or combination of vital signs to alert us to who is going to have a severe disease course,” she said.

Among the 2,634 patients who had been discharged or died by early April, 79% were discharged and 21% died. A total of 3,066 remained hospitalized.

Among patients who did not receive mechanical ventilation, the mortality rate was 19.8% in 18- to 65-year-olds and 26.6% among those over the age of 65.

Hypertension (56.6%), obesity (41.7%), and diabetes (33.8%) were common co-morbidities among hospitalized patients. At presentation and triage, 17.3% had a respiratory rate greater than 24 breaths/minute and 27.8% received supplemental oxygen. The rate of respiratory virus co-infection was 2.1%.

Among patients who were either discharged or died by early April, 373 patients (14.2%) (median age, 68 years [IQR, 56-78]; 33.5% female) were treated in the intensive care unit care, 320 (12.2%) received invasive mechanical ventilation, 81 (3.2%) were treated with kidney replacement therapy, and 553 (21%) died.

A total of 2.2% of discharged patients were readmitted to a hospital during the study period.

Study limitations cited by the researchers included reliance on electronic health records, the relatively brief median post-discharge follow-up (4.4 days), and lack of clinical outcomes data on the majority (53.8%) of the patient cohort who remained hospitalized.

“The absence of data on patients who remained hospitalized at the final study date may have biased the findings, including the high mortality rate of patients who received mechanical ventilation older than age 65 years,” the researchers wrote.

  1. Less than a third of patients hospitalized for Covid-19 at New York’s largest hospital system were febrile at presentation, and just 28% were determined to be in need of supplemental oxygen in a large case series of sequentially hospitalized patients.

  2. Roughly 9-out-of-10 (88.1%) Covid-19 patients who required mechanical ventilation did not survive to hospital discharge.

Salynn Boyles, Contributing Writer, BreakingMED™

This research was funded by grants from the National Institutes of Health, the National Library of Medicine and the National Heart, Lung and Blood Institute.

The researchers declared no conflicts of interest related to this study.

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