Cape hospitals turn to safer alternative to ventilators for Covid-19 patients
Doctors at Cape Town’s top teaching hospitals are changing their approach to treating severely ill Covid-19 patients, placing them on their stomachs and providing them with highflow oxygen therapy to assist their breathing instead of putting them on mechanical ventilators.
The change has been driven by mounting evidence of high mortality rates among Covid-19 patients who are ventilated, which international studies show range from 60% to 95%.
A small local study by the National Institute of Communicable Diseases (NICD) found that nine out of 10 public hospital patients who were put on ventilators did not survive.
Ventilators, and the highly skilled health-care staff required to operate them, are also in increasingly short supply, with Covid-19 cases on the rise.
By Tuesday, the Western Cape reported 992 Covid-19 patients in hospital, 172 of them in intensive care.
High-flow nasal oxygen machines propel warm, humidified, oxygen-enriched air into a tube in a patient’s nose, but they breathe on their own. The therapy is well established and is already used to help patients with severe pneumonia or lung dysfunction.
As Covid-19 is such a new disease, there is limited published research on high-flow oxygen in Covid-19 patients, but the Australian Covid-19 national clinical evidence task force has recommended its use, provided due care is taken to protect staff from the risk of infection.
The most recent clinical guidelines drawn up by the NICD say high-flow oxygen therapy may be considered.
Now doctors at Tygerberg and Groote Schuur hospitals are turning to high-flow nasal oxygen machines to try and improve the chances of Covid19 patients with severe breathing problems. Both hospitals face mounting service demands from Covid-19 patients, as the city is home to about 80% of the Western Cape’s recorded cases.
The results so far were promising, as patients who received high-flow oxygen had lower mortality rates and recovered faster than those who were placed on mechanical ventilators, achieving a higher turnover in ICU, said Tygerberg’s Intensive Care Unit head Usha Lalla.
In a letter published in the South African Medical Journal on May 7, Lalla and her colleagues compared the outcomes of 13 severely ill Covid-19 patients with similar profiles.
All six of the patients who were ventilated died, while only one of the seven on high-flow oxygen died.
Results for a larger number of patients had yet to be published, but about 70% of the Covid-19 patients who had so far received high-flow oxygen therapy at Tygerberg survived, said Tygerberg pulmonologist Coenie Koegelenberg.
It was unclear why Covid-19 patients who were placed on ventilators fared so badly.
“We don’t know if it is the disease, or mechanical ventilation or a reflection of how sick they are. But once intubated, their very chances small, of”getting he said. out of ICU are
Groote Schuur head of pulmonology Keertan Dheda said the hospital’s experience of high-flow oxygen for Covid-19 patients mirrored that of Tygerberg.
Doctors were initially wary of the therapy because of concern that patients would breathe out aerosolised particles containing the coronavirus and infect staff or other patients, but it turned out to be safer than they first thought, he said.
“We are delighted people are investigating these issues, and support further investigation in the space of a controlled trial,” said Andy Parrish, who heads the national health department’s essential medicines committee.
VENTILATORS, AND THE SKILLED HEALTHCARE STAFF REQUIRED TO OPERATE THEM, ARE ALSO IN INCREASINGLY SHORT SUPPLY