Normally when a patient gets ARDS (Acute respiratory distress syndrome) due to reasons other than Covid-19, they do pretty well with mechanical ventilators such is not the scenario with Covid-19 Pneumonia/ARDS. Dr Samrat D Shah, consultant internist at Bhatia says, with his experience of treating multiple critical Covid-19 Patients in the ICU, he with his team has figured out that mechanical ventilators lead to more mortality. The trouble with Covid-19 lung involvement Is, it causes patchy destruction along with ventilation perfusion mismatch, leading to carbon-dioxide accumulation and a Hypoxemic respiratory failure. Hence, it’s very important to use measures which can lead to Alveolar recruitment (to recruit partially destroyed small airways) says Dr Samrat Shah.

THEREFORE, WE FIGURED OUT THAT AIRVO 2 ALONE WITH PRONE POSITIONING IS THE BEST MEASURE TO SAVE MULTIPLE LIVES.

Airvo is a form of HFNC (High flow nasal cannula oxygen therapy) and is not a mechanical ventilator.
It is considered as more of a respiratory support system. Airvo is a humidified with integrated flow
generator that delivers warmed and humidifier respiratory gases to spontaneously breathing patients.
Airvo 2 is made by a New Zealand company called FISHER & PAYKEL.

Advantages of Airvo 2:

1.It washes out Carbon-dioxide which has been accumulated and ensures smooth and effective
oxygenated breathing.
2.It’s better tolerated and more comfortable for the patient.

Disadvantages of Airvo 2:

1.It requires a lot of expertise for setting of the Airvo 2
2.Cost of the machine
3.Disinfection and filter cleaning
4.Lack of internal battery

Systems that deliver warmed and humidified oxygen at high flows through nasal cannulae (HFNC) have been developed and increasingly used for oxygenation in adults.

Advantages of HFNC in comparison with conventional oxygen delivery system includes

1)Enhanced comfort and increased humidification of secretions to facilitate expectoration
2) washout nasopharyngeal dead space to improve efficiency of ventilation
3) provisions of a small positive airway pressure effect
4) high flow rates to minimise the entrainment of room air for

Reliable delivery of fraction of inspired oxygen (FiO2)

How to set

HFNC is best applied in monitored settings such as the ICU. Oxygen is delivered to the patient by wide bore nasal cannulae. We prefer to set the flow rate first typically 20 to 35 l/ minute (ranges 2 to 60 l/ min) The FiO2 (range 21 to 100 percent) is next set to target a desired peripheral oxygen saturation. Further adjustments of both settings can be made depending upon the initial clinical response. HFNC can be administered for prolonged periods (e.g. days) and patients can be switched to conventional low-flow nasal cannulae once the flow rate reaches ≤20 L/minute and FiO2 ≤50 percent.

●HFNC has been successfully used in patients with severe hypoxemic respiratory failure, in current scenario of COVID 19 pneumonia and ARDS we suggest that HFNC is an alternative to other high-flow systems and non-invasive ventilation. Choosing between these systems should be individualized and depends upon clinician preference, institutional availability, patient preference, severity of hypoxemia, and need for ventilation and positive end-expiratory pressure (PEEP).

●The most common use is for oxygenating patients with severe acute respiratory failure (e.g. partial arterial pressure of oxygen to fraction of inspired oxygen [PaO2:FiO2] ratio <300 mmHg) from medical conditions (eg, pneumonia). Less commonly, HFNC has been used to oxygenate patients before and during intubation, to treat and prevent postoperative respiratory failure, and to oxygenate patients during weaning trials and bronchoscopy.

●Contraindications to HFNC include abnormalities or surgery of the face, nose, or airway that preclude an appropriate-fitting nasal cannula. Complications are rare and include abdominal distension, aspiration, and rarely barotrauma.