A major London hospital declared a “critical incident” due to a surge in patients with coronavirus, with one senior director in the capital calling the development “petrifying”.

In a message to staff on Thursday night, Northwick Park Hospital in Harrow said it had no critical care capacity left and was contacting neighbouring hospitals about transferring patients who need critical care to other sites.

The message, seen by HSJ, said: “I am writing to let you know that we have this evening declared a ‘critical incident’ in relation to our critical care capacity at Northwick Park Hospital. This is due to an increasing number of patients with Covid-19.

“This means that we currently do not have enough space for patients requiring critical care.

“As part of our system resilience plans, we have contacted our partners in the North West London sector this evening to assist with the safe transfer of patients off of the Northwick Park site”

The trust said the incident was stood down at 4pm on Friday, as they were able to open some more critical care beds. It has not yet stated how many new beds were opened.

The hospital is run by London North West University Healthcare Trust, which has reported six deaths related to coronavirus, all at Northwick Park.

The potential lack of critical care beds in England has been the major concern around coronavirus, and trusts are currently repurposing wards and retraining staff to try and create more capacity. National leaders have suggested the number of critical care beds likely needs to rise by several times.

A senior director at another London acute trust told HSJ: “Given we’re in the low foothills of this virus, this is f***ing petrifying.

“The thing people aren’t really talking about yet is that we are going to have to quickly agree some clinical thresholds for admissions to intensive care. This is what the Italians have had to do, and whether its set at [a maximum age of] 60 or whatever, we are going to have to do something similar. There’s no way we’re going to be able to scale up to the level we need otherwise.

“The trusts in outer London seem to be hit much worse at the moment, probably about two weeks ahead of the rest of the country. Barnet, Lewisham and Greenwich, Epsom and St Helier, North Middlesex and Hillingdon are all struggling.

“I was in denial about the seriousness of this virus a couple of weeks ago, but not anymore.

“I’m now on calls with commissioners about getting more people out of hospital and into the community, and they’re saying ’yes that’ll be done in the next week’, and I’m on the verge of screaming at them. Things are going completely nuts.

“And there’s a real problem with private care homes refusing to take patients back unless they’ve been tested for covid-19. But that’s not the national guidance currently and there just aren’t enough testing kits to do it.”

A spokeswoman for LNWHT said: “Critical care capacity for patients with coronavirus is being organised on a cross-London basis so that hospitals and organisations work together to deliver the best possible care for patients.

“This kind of coordinated, flexible response is one of the NHS’s strengths but with staff pulling out all the stops they need the public to play their part too, by following the expert guidance on washing your hands, staying at home and using health services responsibly.”