30/04/2020
Limits of Medicine- another COVID-19 Study, and future actions
30 April 2020
People are asking why people getting sick with COVID-19 in aged care homes are not on ventilators. The reason is probably that the ventilators are unlikely to save them. One also needs to ask what is the Key Performance Indicator of an ICU. When I worked in them, it was leaving the unit alive. The statistics of this have always been improving, because as the units get bigger they take less sick patients. It the unit has 4 beds as they used to, and have the 4 sickest patients in the hospital, they will have much worse survival statistics than if they take 40 patients including a lot who are scheduled to go there for a few days after elective heart or other surgery. But the question still remains for the ones that did not get there in a planned way, what level of life-functioning will they have after discharge? Is no one allowed to die without some time on a ventilator, however hopeless the quest and whatever their quality of life after discharge?
A new survival study of COVID-19 has been published in JAMA (Journal of the American Medical Association) from a number of hospital in New York. It is an incomplete study in that its final results are not available, published presumably in haste to get some results out. It looked at 5,700 patients, but only had results for 2634 who had reached an end-point, they had either been discharged or died. (The other 3066 are still in hospital). 14% of the 2634 needed to go to ICU and 12% needed to be intubated (i.e. on a ventilator with a tube down to the lungs). Of those who needed intubation in the 18-65 year age group 76% died and in the over 65s 97% died. 3% needed kidney replacement therapy (dialysis). Overall 21% (553/2634) died.
It might be noted, however that no one under the age of 20 died, and the 5700 were not entirely typical citizens in that their median age was 63, and they had co-morbidities; 57% were hypertensive, 41% were obese and 34% had diabetes.
At the time of triage (assessment for admission) 31% had fever, 17% had a respiratory rate greater than 24/min and 28% needed extra oxygen. This is relevant as there is a lot of discussion as to what are the most important signs and symptoms. (Cough was not mentioned in the article).
The New York JAMA results are not dissimilar to an earlier Wuhan Study from The Lancet (24/2/20 Xiaobo Yang et al) studying the outcome of 710 hospital patients. Of these 52/710 were classified as critical (7%). Of the 52, 29 needed ICU for ventilator support (= 56% of the hospital admission and 4% of the total). Of the 29 who needed ventilatory support, 22 needed intubation and of these 19 died and 3 survived. (i.e. 86% of those who needed to go on ventilators died). Of the 29 who needed ventilatory support, 23 died (76%).
To compare the survival; in the US study, 14% of hospital admissions went to ICU and 21% of these died, which is roughly 3% of the number admitted. In the Wuhan study 4% of the total patients needed ICU and 76% of these died, giving a mortality of about 3% also.
There is a lot of difference between countries in terms of the number of cases and the fatality rate. Looking at the numbers on worldometerinfo/covid today the UK leads the fatality rate with 15.8%, followed by Belgium 15.7%, France 14.5%, Italy 13.6%, Sweden 12.3%, Netherlands 12.1%, and Spain on 10.3%. Next there is quite a drop to the next group with Switzerland on 5.8%, the USA on 5.8%, Denmark on 4.4%, Germany and Portugal on 4.0%, Austria on 3.2% and Norway on 2.6%. The USA is earlier in the epidemic, which may make its numbers lower, but the question is why Germany and Denmark can do so much better than adjacent France and the Netherlands. Perhaps it is because they have managed to stop it getting into their old people’s facilities where the fatality rate is much higher. Australia and New Zealand are looking very good at 1.3%, which may be for the same reason- many of our cases were contacts from cruise ships, and two nursing homes here have had conspicuously high death rates, but one might reflect that there are only two of them. The lesson from this is that it is very important to isolate certain areas, and of course if its gets into vulnerable populations where isolation is difficult, such as Aboriginal communities with many transient members, it will not be able to be traced and controlled and there will be ongoing infections forever.
The nursing home managers resisting the government’s more open policy have very sound reasons, and the danger of opening up society when ‘community acquired’ infections are still occurring is high. Undiagnosed cases have a high chance of infecting vulnerable populations which will either result in a lot of deaths or an ongoing source of infections or both.
Australia’s figures today from the health.gov.au COVID website are that there have been 6753 cases in Australia, of which 5714 have recovered and 91 have died. This leaves 948 cases of which 34 are in ICU and 89 are in hospital. (It is not clear whether the 34 are included in the 89). This means that there are either 859 or 825 still active cases that are not in hospitals. There were 8 new cases yesterday, so the other question is whether they came from quarantined people, who hopefully will not spread the infection, or ‘community acquired’ cases, still popping up at random and in danger of infecting a new group.
