The intensive care unit at the Royal Stoke University Hospital raised its alert level from three to four after it had 38 Covid-19 patients on ventilators on Friday evening, leaving just seven available, the Stoke Sentinel reported.
They were among 322 coronavirus patients in beds across the Royal Stoke and Stafford's County Hospital, which are both run by the University Hospitals of North Midlands NHS Trust (UHNM).
Seriously ill Covid-19 patients have had to be transferred out of Staffordshire to other hospitals in the Midlands due to the strain on capacity.
Hospitals in the county have come under far more pressure during the second wave of the pandemic than they did during the first wave.
At the start of November Staffordshire already had 30 per cent more coronavirus patients in hospital than it did during the peak of the first wave in the spring.
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UHNM chief executive Tracy Bullock thanked other hospitals for sharing the load and apologised to patients for them having to be moved.
"Difficult day working with our regulators, critical care and major trauma networks to seek more formal support from other Major Trauma Networks due to lack of critical care capacity," she tweeted.
"Very grateful to those hospitals who have already accepted patients who we can’t provide critical care capacity for.
"We also apologise to our patients and families who are affected by this. We absolutely recognise this is less than ideal and very upsetting for them."
An arrangement with NHS trusts in Birmingham and Coventry and Warwickshire to transfer critically-ill patients is in place until midday on Tuesday and is reviewed daily.
However several other intensive care units in the Midlands are also working at full stretch and options for hospitals to help their neighbours by transferring patients are "drying up," according to the Health Service Journal.
Leaked data seen by the HSJ showed the Staffordshire trust is one of several that have had to transfer critically ill patients to other sites. The Royal Stoke has transferred the most, with 12 patients transferred to units in other hospitals this week.
Several units in the region are well over 100 per cent of their normal critical care capacity, the HSJ reported, with Walsall Healthcare recording the highest at 169 per cent according to the Midlands critical care network dashboard.
Ms Bullock said the decision to transfer patients out of the hospital was not something "taken lightly" and said that pressure would hopefully drop as the number of new cases continues to fall.
In the week to November 23, Staffordshire had an infection rate of 285.7 cases per 100,000 people compared to 187.2 across England.
In Cannock the rate was 235 cases per 100,000 people and in Stoke it was 403. Stoke's rate is higher than anywhere else in the West Midlands, with Dudley (383.7) and Sandwell (372.4) second and third.
The highest rate seen in Staffordshire was in the seven days to November 14 when it reached 426.8.