Thread by @CoronavirusCast

My research indicates there are four key elements that could potentially collapse the medical system of a given nation in response specifically to the #coronavirus, and we will use the US as the example, any one of which can be fatal, and every one of which is a problem. 1/n

The four critical areas for #Covid19 are:
1) Lack of PPE (masks) leading to loss of workers (HCW)
2) Lack of antiviral drugs (Remdesivir/Chloroquine) for stabilization of patients
3) Lack of ICU bed capacity
4) Lack of Ventilators for oxygen support
2/n

As the Washington Post reported and @LizSpecht covered brilliantly last week (threadreaderapp.com/thread/1236095…), we have sufficient mask capacity at current production and consumption to protect our workers in health care (HCW) for two days under proper usage guidelines. 3/n

This means that we should expect as HCW take on a burgeoning case load, many will be removed from active duty and some will become violently ill, including die, from this lack of protective equipment, reducing critical care capacity through this crisis. 4/n

From multiple studies, we've seen that Remdesivir has been used with apparently some efficacy to help reduce the severity of #COVID19 cases, but supplies were limited, and although this is not confirmed, it is likely production of this drug involves Chinese components. 5/n

We cannot be sure of the supply chain disruptions and how badly Remdesivir, or Chroloquine, another treatment commonly employed by China has been, but we know domestic capacity and supply is short, not increasing, and unlikely to receive foreign help increasing severe risk. 6/n

The Society of Critical Care Medicine offers two different ways to calculate the total of ICU beds in the US as a third capacity problem. (sccm.org/Communications…) The estimates of 100k beds with 70% occupied, represent a critical shortfall in infrastructure. 7/n

If you convert every neonatal unit, every operating room, and removed all current ICU occupants, the maximum ICU number is appx. 150k beds in the US. Other countries have amounts equal to their population at only half this amount of less, like England which has 3,600 beds. 8/n

While you can possibly add beds, the fourth and perhaps most deadly choke point is the lack of ventilators, which Italian doctors are reporting are the single most critical component to helping the 10% of acute and 5% of critical patients survive. (news.sky.com/story/coronavi…) 9/n

This research from the Sacramento Bee (sacbee.com/news/local/hea…) indicates that we have appx. 160k ventilators nationwide at hospitals with a strategic nat'l reserve of 10k. This will be the critical limitation of care with patients needing to spend 10-30 days ventilated. 10/n

While there are a small number of respirators to be scavenged from the market and from nursing homes, although at risk to those with existing need, the lack of ventilators is what is causing the most problems in Lombardy as patients experience bilateral institial pneumonia. 11/n

Absent the ability to provide support to patients who cannot breathe on their own, the case fatality rate jumps markedly for the estimated 15% of the population with severe cases and 5% of the critical cases. The CFR could increase as much as tenfold as it did in Wuhan. 12/n

This danger was anticipated for an influenza epidemic as is evident by this planning document by NY State, one of many studies and plans that highlighted a shortfall of ventilators, imagined here for influenza (health.ny.gov/regulations/ta…) but relevant for #COVID19 13/n

Worth noting in the NY Document, as previously mentioned by the UK NHS and in practice in Italy at this moment is doctors are being to forced to prioritize who lives and dies based upon choosing which patient get to use the ventilator based most often on likely mortality. 14/n

If we assume the US supply is 170k ventilators, and that one in every ten people infected with the #coronavirus will require access to this or face mortal peril, we reach a point of saturation beyond which medical intervention is overrun when 1.7 million people are infected. 15/n

If we also assume that 10k people are infected now, in line with the best modeling, and that cases double every six days absent quarantine or other measures to reduce the transmission rate (r0) further, we will reach the point at which that number are infected by 4/24. 16/n

Assume there is a delay of 9 days between infected cases becoming symptomatic and in need in line with the median case study average to expressed pneumonia, and we reach the point where medical collapse in terms of ability to treat #COVID19 is reached on 4/15 - one month. 17/n

Absent public quarantine, this measure is conservative, and assumes that health care workers are not overrun, which they will be, medical supplies do not run out, that mask shortages don't lead to shutdowns or absenteeism, and that case spread is constant. 18/n

We see examples that places like Sacramento, presumably following @CDCGov guidance, (sacramento.cbslocal.com/2020/03/09/sac…) are following this idea that post case containment that we should let the #coronavirus run its course. Other counties are doing the same. 19/n

The same basic strategy appears throughout the English speaking world, as having conducted fewer tests, presumably to prevent panic, there seems to have been a decision to take this at once at maximal death over minimal time as the UK is also doing.(bbc.com/news/uk-518123…) 20/n

However, the consequences of that decision, which we only have a narrow and rapidly closing window to reverse, is to contemplate a truly staggering mortality figure in those countries which choose to let it burn. Numbers vary depending upon the percentage infected. 21/n

But let's assume that of the 20% of the population of #Covid19 victims, that amongst the 5% who need critical care, none survive absent ventilators. Let's assume for the 15% who need acute care, a 50% mortality rate, which we can only presently guess. 22/n

We would expect the #coronavirus CFR to jump to around 12% due to these deaths which could have potentially been prevented absent shortage of ventilator supply. The US population is 330 million. Multiply the % of people infected x 12% to get mortality figures. 23/n

To put numbers to the estimate.
10% infected: 8 million deaths
25% infected: 20 million deaths
50% infected: 40 million deaths

Once pass the saturation point, 1.7 million cases, ~.5% or 1/200 infected, this will be the new CFR for #Covid19 or worse. 24/n

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