Safer way of sharing ventilators for COVID-19 patients developed

Scientists, including one of Indian origin, have come up with a new approach to sharing ventilators between patients, which they believe could be used as a last resort to treat COVID-19 patients in acute respiratory distress.

The researchers, including Shriya Srinivasan from the Massachusetts Institute of Technology (MIT) in the US, noted that as more COVID-19 patients experience acute respiratory distress, there has been much debate over the idea of sharing ventilators.

This involves splitting air tubes into multiple branches so that two or more patients can be connected to the same machine, said Srinivasan, lead author of the research published in the journal Science Translational Medicine.

Several physicians' associations have discouraged this practice, saying it poses risk to patients, because of the difficulty in ensuring that each patient is receiving the right amount of air, the researchers said.

Now, a team at MIT and Brigham and Women's Hospital has come up with a new approach to splitting ventilators, which they believe could address many of these safety concerns.

They have demonstrated its effectiveness in laboratory tests, but they still caution it should be used only as a last resort during an emergency, when a patient's life is at stake.

"We hope this approach, which requires off-the-shelf components, can ultimately help patients in extreme need of ventilator support," said Giovanni Traverso, an MIT assistant professor.

"We recognise that ventilator sharing is not the standard of care, and interventions like this one would only be recommended as a last recourse," Traverso said.

Ventilators are machines that help people breathe by delivering oxygen through a tube placed in the mouth or the nose. Countries around the world have struggled to obtain enough ventilators to handle the Covid-19 outbreak, the researchers said.

The MIT team incorporated flow valves, one for each patient's branch, that allow them to control the amount of air that each receives.

"These flow valves allow you to personalise the flow to each patient based on their needs," Srinivasan said.

"They also ensure that if one patient either improves or deteriorates, quickly or slowly, there's a way to adapt for that," she said.

The setup also includes pressure release valves that can prevent too much air from going into one patient's lungs, as well as safety measures including alarms that go off when a patient's air intake changes, the researchers said.

To create their setup, the researchers used parts that are normally available in a hospital.

The parts could also be obtained at hardware stores and sterilised, they said.

A typical ventilator produces enough air pressure to supply six to eight patients at a time, but the research team does not recommend using one ventilator for more than two people, as the setup becomes more complicated.

The researchers first tested their setup using a ventilator to split airflow between a pig and an artificial lung -- a machine that simulates the function of the lungs.

By changing the properties of the artificial lung, they could model many of the changing conditions that might occur in patients; they also showed that the ventilator settings could be adjusted to compensate for them.

The researchers later showed that they could ventilate two animals on one ventilator and maintain the necessary airflow to both.