Why important to flatten COVID curve for healthcare capacity, England

→ 1,000 critical care beds (England)

→ 20,000 cases (simultaneously) wd overwhelm system

→ important to flatten curve

→ 319 cases if double every 3 days = 20K+ in 21 days.

→ important to flatten curve

I am not a virologist, but this is an example math for why some argue to flatten the curve is important. In Dec 2019, in England, there were 4,048 adult critical care beds available and 3,048 occupied. (There were 309 paediatric intensive care beds available and 246 occupied.)

This is out of approx 130,000 to 140,000 hospital beds in England. These beds have approx 90% occupancy end of 2019.

The five main specialist centres in England are: the Royal Free and St Thomas', in London, and sites in Liverpool, Sheffield and Newcastle. Between them, they can care for 100-150 patients at any one time. There are 25 other sites but without factoring in isolation, ventilation requirements and the like, plus other occupied beds we are looking at capacity around 1,000 critical care, up to 2,000 if you want to push out other critical care.

In China out of a study of 44,000 cases 14% were severe and 5% critical. The severe patients might not all need an ICU bed (though likely would need a bed) but the 5% critical cases (approx) likely do.

This suggests if England hits 20,000 cases at a point in time then that’s a critical overload situation with 1,000 needing care.

England has about 319 cases as of 9 March with a doubling day of approx 3 (this will not be stable, we must hope! - but it has been 3 for a few days now) but that means in 3 days time cases would be 638. But it also means that in between 21 to 24 days (7 to 8 double day periods), we would hit 20,000 to 40,000 cases. That’s what would a plausible exponential growth model could suggest, if we had no containment - and Italy might hit that number if containment fails in late March or April.

As of 9 March the world ex-China (28K) is at around 5 doubling days driven by Italy (7,375) and Iran.

How strict our containment/slowing must be without grinding our economies to a halt is for societies to decide. But perhaps Italy is a case study of how it can get, from a doctor in Italy.

As Italy with also in the range of 1000-2000 ICU beds free (they are looking for more everywhere) are approaching a tipping point.