Doctors in Pune are increasingly using high-flow nasal oxygen (HFNO) to treat respiratory distress in Covid-19 patients, instead of straightaway putting them on mechanical (invasive) ventilation.
This treatment modality was not easily available for patients during the H1N1 pandemic over a decade ago.
Oxygen therapy comes in three forms: via normal oxygen masks, the HFNO and invasive or mechanical ventilation. “The HFNO method is simple and cheaper than a ventilator. It is a bridge between the oxygen mask and the ventilator. And it has been producing much better results in selected patients,” said senior physician Mukund Penurkar, secretary of the Association of Physicians of India, Pune branch.
Analysis of Covid-19 data has revealed that nearly 20% of patients suffered damage to the lungs, which reduced oxygen supply in the body — a condition known as hypoxia (breathlessness). Doctors treating this problem rely on oxygen via facemasks (or a Ventimask system). A majority of patients have been cured via this method.
“But in a few patients, oxygenation using cannula (tube) is not enough to maintain optimum blood oxygenation levels. In such cases, an HFNC cannula has proven to be an extremely beneficial remedy,” Penurkar added.
The HFNC is a piece of equipment that delivers warmed (37°C) and humidified (100% relative humidity) oxygen at very high flow rates (nearly 60 litres per minute) through plugs that are fitted to patient’s nostrils.
Anesthetist Milind Belsare said: “Unlike standard oxygen therapy, which uses dry O2, the HFNC’s warmed and humidified oxygen maintains body temperature, reduces airway inflammation and maintains mucociliary function — the cleaning mechanisms of the respiratory tract.”
A Sassoon hospital doctor said they were increasing HFNO beds from 12 to 50.
But not every patient with respiratory distress will benefit from this system. Intensivist Urvi Shukla said, “The HFNO works for patients who don’t need a lot of oxygen to keep saturation levels at 90%. But it won’t help if patients’ ability to breathe on their own is compromised. Also, HFNOs cannot deliver very high pressure into the lungs, which may be needed in very severe cases.” Shukla heads the ICU of Symbiosis University Hospital and Research Centre at Lavale. Acqro