New Delhi: In the latest Standard Operating Procedure (SOP) for Covid-19 released by AIIMS Patna, doctors have emphasised using prone positioning to manage blood oxygen levels at hospitals and during isolation at home. Prose position refers to lying on the chest and stomach.
According to the protocol released Wednesday, doctors recommend that patients should try different body positions, even in home isolation, to allow bloody oxygen levels to improve.
These include prone positioning, lying on the right and left side and sitting in an upright position — each for 30 minutes to two hours.
The SOP, however, does not mention the antiviral drugs remdesivir and favipiravir, of which there is a countrywide shortage currently. Remdesivir has been found to be ineffective in reducing the risk of death in Covid patients while favipiravir has also shown no benefit among Covid patients.
The protocols instead recommend the use of dexamethasone and other oral steroids in case of both mild and moderate disease, but only if laboratory tests indicate signs of inflammation. Studies have indicated that dexamethasone reduces death risk in Covid patients.
The SOP recommends other medicines such as paracetamol to manage fever as well as pantoprazole if a patient is experiencing gastric symptoms.
Of all the drugs that have been approved for Covid management, the AIIMS protocol only recommends the use of tociluzumab, an arthritis drug that studies indicate can reduce death risk in hospitalised Covid patients.
How prone positioning helps?
Prone positioning has been recommended in ARDS (Acute respiratory distress syndrome) patients since 2013, when clinical trials showed it significantly reduced death risk among the patients on ventilators.
“While lying on the back, lung fluid that occurs in ARDS accumulates in the bottom lung regions, and the heart and abdominal contents further compress these dependent lung regions. This leads to non-uniform ventilation,” Sanja Jelic, Associate Professor at Columbia University Medical Center, had told ThePrint in an interview.
A study by Jelic’s team, published in JAMA Internal Medicine, in June last year, was one of the earliest to show that prone position for awake, spontaneously breathing patients with Covid-19 severe hypoxemic respiratory failure was associated with improved oxygenation.
The top and frontal lung units, which are regions that receive less blood circulation, get delivered a higher volume of ventilation when a person is lying on their back.
As a result, the lung regions that receive more blood are left poorly ventilated, leading to hypoxemia or abnormally low levels of oxygen in the blood.
“Prone positioning leads to a more homogeneous distribution of ventilation than lying on the back, improving matching of ventilation and perfusion (rate of blood delivered to a tissue),” Jelic explained.