Covid-19 pandemic: ventilator death toll sobering but ‘not conclusive’

A snapshot of mortality among Covid-19 patients on ventilators in SA is sobering, but too small and incomplete to provide a reliable picture of patient survival.

Most people with Covid-19 who go onto mechanical ventilators will die, international studies show. “Outcomes internationally have shown mortality rates of 60% to 95% in many countries, including the US, China and Italy,” said Wits University infectious diseases specialist Dr Jeremy Nel.

The National Institute for Communicable Diseases Covid-19 hospital sentinel surveillance report found that nine out of 10 patients ventilated in public hospitals die.

It found that the death rate in private hospitals was a lower 30%. This does not match global trends and Nel said the outcome was probably because the sample of 61 was too small and the time period too short.

“Almost half the ventilated patients in the private sector data were still on a ventilator at the time the statistics were calculated, and so the number of deaths in this group can be expected to rise with time,” he said.

“The numbers reported from the state sector are very small at this point, and so drawing firm conclusions isn’t wise. In addition, the surveillance data is not comprehensive— many hospitals aren’t yet included — and so the results of the surveillance may not be generalisable across the country.”

Professor Guy Richards, director of critical care at Charlotte Maxeke Johannesburg Academic Hospital, said the management of Covid-19 patients in both public and private hospitals in Gauteng followed a similar approach.

“Essentially, we try to avoid mechanical ventilation,” he said, listing critical steps, including high-flow nasal oxygen, they would take to treat Covid-19 admissions before ventilation might become necessary.

“If multi-organ failure ensues or prolonged mechanical ventilation is required, then mortality increases exponentially.”

Doctors in the Western Cape are starting to record promising results from “proning ” —positioning seriously ill patients on their stomachs — and using high-flow oxygen rather than putting them on ventilators.

The health of patients being admitted to public hospitals often does not compare to those insured patients being admitted to private hospitals, doctors noted, making comparisons between patient outcomes unscientific.

“The socioeconomic conditions of populations are totally different between public and private hospitals,” said professor Landon Myer, head of the University of Cape Town school of public health and family medicine.

“Private has the wealthiest,healthiest 15% to 20%, while 85% of people are in public health care, which has the higher burden of disease.”

Co-morbidities are common among patients relying on public hospitals, and intensive care unit beds are scarcer per patient given their limited resources.

“For those patients, the disease has to be quite severe but there also has to be a chance of survival, to help ensure scarce resources are used optimally,” said Myer.