Staff at the capital's University College Hospital say they are being forced to to make the heartbreaking choice of which patients to prioritise as they tackle a surge in young people left fighting for their life.
Patients are dying 'at dramatic speed' as medics in the intensive care unit are forced to choose those with the best chance of survival.
In the last fortnight the number of coronavirus patients being admitted to hospitals in London have doubled.
Dr Alice Carter has compared the current climate to an elastic band that is close to snapping.
"It gets to a point where you stretch so far it never returns back to its baseline," she said.
Coronavirus patients have shared their experience of being admitted to the ward with some saying there is awareness that a lack of ventilators mean people will died.
One patient Attila Karayel, 67, said: "It knocked me out. I didn't think I would make it.
"There is no oxygen around. It's very frightening."
Ashleigh Shillingford, deputy sister at University College Hospital, told the BBC: "We are so stretched we have to prioritise, and prioritising care is not the NHS I grew up in. We shouldn’t have to choose what patient gets what care first.
"People are asking for your help and you don’t know who to help first. The patients are losing their lives at a dramatic speed. We are not just getting older people. This is young people that we are getting, people my age."
The hospital has three times as many critically ill patient as normal.
The increase has forced University College Hospital to convert its operating theatre’s and children’s units into intensive care units to deal with the demand.
