Oxygen supplies at a Hertfordshire hospital inundated with coronavirus patients became so precarious last week that officials considered how to decide who should receive the gas and who should miss out and likely die, the Guardian understands.

The oxygen system at Watford general hospital came close to breaking point on Saturday, when a critical incident was declared and staff had to tell the public not to come to the hospital. Some patients were moved out to prevent the vital system failing.

Last week, health planners in Hertfordshire, where more than 800 cases of coronavirus have been recorded, became so concerned about oxygen supplies they alerted the military that they might need help. The area has been under huge pressure from the Covid-19 pandemic, with mortuary space filling up and plans being made to increase capacity four-fold. As of 5pm Thursday, 29 people had died at West Hertfordshire Hospitals NHS trust hospitals after being diagnosed with Covid-19. The trust is responsible for Watford general as well as Hemel Hempstead and St Albans City hospitals.

A senior clinician said: “They were [consulting] the hospital ethics committee every day and considering who they were not going to oxygenate and ventilate if they needed it, and making decisions about who would be triaged to not have oxygen and die.”

The decision to announce a critical incident on Saturday meant no one had to go without oxygen, the trust said.

Oxygen therapy is key to the successful treatment of advanced cases of Covid-19, and last Tuesday NHS England warned hospitals across the country about the risk to supplies in an urgent patient safety notice. It highlighted the dramatic recent increase in hospitals’ use of ventilators and in particular CPAP machines, which dispense ventilation through a face mask.

The pressure on Watford general’s oxygen system was not unexpected, according to documents seen by the Guardian.

Last week, healthcare planners in the area said they pleaded with the government and the NHS to urgently approve works to the hospital’s oxygen system and warned NHS England on Wednesday that the situation was critical.

However, NHS England said that it had alerted trusts, including West Hertfordshire, to the need to prepare their oxygen systems in February when the threat of the coronavirus epidemic was looming.

“All trusts were written to by NHS England in February reminding them to carry out engineering checks on ventilation equipment, and were further issued with guidance on how to use the kit safely, on 1 April,” a spokesperson said.

Works to overhaul Watford general’s oxygen supply system had been planned before the outbreak, but were put on hold. Local planners felt their attempts to get them urgently restarted were frustrated by communication difficulties in central government, the documents show.

On Friday, the day before the critical incident was declared, the planners considered making a military aid request and began a process that could allow the armed forces to step in and help.

“On 30 March, the multi-agency group in Hertfordshire asked the government to get the works moving as they had been planned for some time, and they noted how urgent they were, but nothing happened,” the senior clinician said. “There was no response. On 1 April, the trust reported that they were at max capacity for oxygen and we raised the issue with NHS England and got nowhere.”

West Hertfordshire Hospitals NHS trust declined to comment beyond giving its account of the incident on Saturday.

The trust said it was “a technical issue with our individual hospital’s oxygen equipment, which does not pose any risk to our patients”. It added that “a safe level of oxygen [was] maintained throughout”. The incident was triggered by growing concern that the system was close to capacity, sources said.

However, NHS England said it was not a result of capacity problems “but due to a technical fault in their oxygen ventilation equipment, which engineers are now fixing, with the critical incident stood down last night.”

Referring to consultations with the ethics committee about what would happen in the event of severe oxygen problems, the NHS England spokesperson said: “The incident did not lead to any patient harm, however in any major incident it is absolutely right that hospitals plan for every possible scenario to manage patient care.”

Daisy Cooper, Liberal Democrat MP for St Albans, said: “I raised the question of possible oxygen shortages with the government privately more than a week ago and this weekend Watford general A&E had to close for a day because its oxygen equipment malfunctioned.



“The government must now ensure that Watford general has whatever resources it needs to shore up ventilation systems, given the expectation that numbers of Covid-19 patients will continue to rise in the coming days.



“For hospitals like Watford general which are near capacity, we need to know now what steps will be taken to signpost coronavirus patients, in real time, to the nearest medical facilities with capacity. The government must commit that, if needed, it will relocate Hertfordshire patients with coronavirus to the new Nightingale hospital in London, or build additional field hospitals to serve areas including Hertfordshire.”

A senior consultant in London warned that hospitals in the capital were also reaching capacity. “We had a meeting at midday on Saturday with other south London hospitals to look at beds data, as we are pretty much full,” the doctor told the Guardian.

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“The Nightingale hospital will only open just in time, and for the next few days we are managing capacity as best we can … everywhere is up to the limit. That is reflective of elsewhere in London,” he added.

He said that transferring patients across hospitals through the South London transfer network has “saved multiple lives and them offloading us prevents us from making difficult choices. We would have run out of ventilators if we could not have transferred patients out to other hospitals”.

He said: “My fear is that I will end up confronting a patient who I would need to intubate but do not have the machines to do it, so being unable to help a patient as I don’t have the kit. I hope not to be in that situation, but the fear would be that I am.”