Image: Damien Schumann

SA study shows nasal oxygen could help fight Covid-19

CAPE TOWN- Doctors at Tygerberg Hospital have confirmed in an academic study that non-invasive oxygen therapy could potentially save thousands of lives while also providing a more patient-friendly experience.

The research article, published earlier this week in The Lancet’s EClinical Medicine, found that they were able to successfully treat half of all their critically ill Covid-19 patients by using high-flow nasal oxygen (HFNO) and avoiding mechanical ventilation.

This form of therapy channels oxygen into the patient’s lungs through nasal tubes at a high flow rate – up to 60 litres per minute. It does not replace mechanical ventilation but provides an extra ‘weapon’ in doctors’ arsenal in the fight against Covid-19.

The medical experts from Stellenbosch University (SU) and the University of Cape Town (UCT) consider HFNO to be ‘gentler’ on patients than mechanical ventilation and allows patients to eat, talk and engage with others in the ward.

When the first Covid-19 patients with acute respiratory distress were admitted to Tygerberg Hospital’s intensive care unit (ICU) in March this year, doctors treated them according to the internationally recommended regimen of mechanical ventilation.

Ventilation is an invasive treatment that requires a tube to be inserted into the patient’s airway. This can cause severe discomfort and necessitates sedation in some patients.

Internal medicine specialist with SU’s Faculty of Medicine and Health Sciences, Dr Usha Lalla, said: “The first seven patients all received ventilation, and unfortunately all of them died.  I remember the day so clearly – two of the patients died on the same day, and the ICU was in tears,”

Lalla, who also manages the Covid-19 ICU, said that the first patient treated with HFNO made huge improvements within five days – in stark contrast to patients who have to be ventilated for two to three weeks. “This gave us hope that we might not experience the carnage seen in other parts of the world,” says Lalla.

SU pulmonologist who also works in Tygerberg Hospital’s Covid-19 ICU, Prof Coenie Koegelenberg, said: “for a resource-constrained setting in the midst of a pandemic, this had a massive impact on the management of patients”.

Dr Usha Lalla and Prof Coenie Koegelenberg. Image: Damien Schumann

Unlike mechanical ventilation that has to be managed in the ICU, HFNO can be administered in the general ward – provided that the hospitals’ infrastructure provides for the higher flow of oxygen required. It can also be safely managed by non-ICU trained doctors and nurses, saving on the country’s sparse healthcare resources.

The doctors from SU collaborated with Prof Greg Calligaro’s team at UCT to combine data of approximately 300 Covid-19 patients who received HFNO therapy at these facilities. The resulting research article is by far of one of the biggest studies to date on the therapy, not only in Covid-19 patients but for any form of pneumonia.

“Our study showed that HFNO can be successfully utilised to avoid the need for mechanical ventilation in half of all patients with severe disease,” says Koegelenberg. “These patients fulfilled the criteria for acute respiratory distress syndrome, and if the recommended treatment protocol was followed, would all have had to be mechanically ventilated – yet we managed to support them successfully without it.”

“High flow made an enormous difference to our capacity to treat patients during this pandemic. But it was no easy feat changing tack from ventilation to HFNO in the middle of a pandemic,” comments Lalla. “Everybody just pulled together – health workers, hospital management, clinical and general engineers and volunteers. Everybody just did what needed to be done… and it was amazing.”


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