Research conducted at Tygerberg Hospital and Groote Schuur Hospital has revealed that a low-resource alternative to mechanical ventilation could be used to treat Covid-19 patients. This follows the successful treatment of selected critically ill Covid-19 patients using high-flow nasal oxygen (HFNO) therapy.
This research, which was published in early October, comes from medical experts from Stellenbosch University (SU) and the University of Cape Town (UCT).
“What we found was that we had an overall success rate of about 52% of patients surviving to hospital discharge and we found that just less than half of the patients had been treated with [HFNO] alone,” said dr Greg Calligaro, an associate professor at UCT.
This meant that the patients didn’t need to go to ICU and did not need to have the costly intervention of ICU care on a mechanical ventilator, he said.
“We started collecting data in April and we finished at the end of July,” said Calligaro.
The benefits
Critically ill Covid-19 patients would generally require mechanical ventilation, an invasive treatment which requires a tube to be inserted into the patient’s trachea, explained dr Usha Lalla, manager of the Covid-19 Intensive Care Unit (ICU) at Tygerberg Hospital.
HFNO, on the other hand, is a non-invasive oxygen therapy that channels oxygen into the lungs through nasal tubes at a high flow rate, said Lalla.
“The normal nasal cannulas will deliver oxygen at around 15 litres per minute, while HFNO will deliver up to 60 litres per minute,”explained Lalla.
This allows for a higher level of oxygen to be administered at a more precise speed, explained prof Coenie Koegelenberg, a SU pulmonologist who also works in Tygerberg Hospital’s Covid-19 ICU.
“The advantage is that the patients are awake…It’s reasonably well tolerated and [patients] can eat, drink and talk when being administered [HFNO],” said Koegelenberg.
Unlike ventilation, that has to be managed in the ICU, HFNO can be administered in the general wards and doctors and nurses “don’t generally need to be ICU-trained to administer [HFNO]”, according to Lalla.
Starting the research
Doctors at Tygerberg Hospital started considering HFNO as a treatment option around the beginning of April, said Lalla.
At the time, a few anecdotal reports started to emerge on the use of HFNO therapy to treat Covid-19 patients, but there was still a general reluctance to use this form of treatment, said Lalla.
“Our first seven patients – we intubated all of them – and the first six actually died. And then we started high-flow,” she said.
HFNO does not replace mechanical ventilation but is purely for patients where receiving oxygen is the problem, said Koegelenberg.