ICU patient outcomes from COVID-19

There are are a lot of numbers bandied about estimating the outcomes of patients in intensive care with COVID. Data from overseas is probably pretty accurate. It’s just that by the time you think about potential differences in admission criteria and standards of care, you subconsciously begin to discount its relevance.

In the UK the best source is the Intensive Care National Audit and Research Centre (INARC). Despite the effectively universal coverage of intensive care in the UK, it is worth noting that the published data only covers patients with positive COVID tests. We are also relatively early in the process, so the outcomes of many patients are still not known even though some may have been ventilated for four plus weeks.

The dataset is interesting because it also compares COVID to non-COVID pneumonia. The numbers from 18 April give some pretty sobering top level messages from an already large cohort of patients - so far 2396 have had outcomes reported (i.e. the patient has been discharged from intensive care or is dead). A similar number of patients are still receiving medical treatments. 

One quick caveat – this data only covers admissions to intensive care not all patients in the hospital. There is a myriad of reasons why patients may not get to intensive care and hence will appear under-represented. Many older patients with multiple comorbidities are likely to have respect forms where they express their wish not to receive invasive and potentially futile medical interventions. There are estimates that only about 1 in 10 patients getting to a hospital are admitted to intensive care.

Men are disproportionately affected compared to ‘normal’ viral pneumonia: 72% of patients admitted to critical care are men. Men are also more likely to die (53%) compared to females (45%). Of note, this disparity is far more pronounced than for non-COVID pneumonia where males mack up 54% of patients. What is it about COVID?

Half of the patients die even after receiving intensive care - We like to think of intensive care as a panacea, yet overall 51% of patients admitted to intensive care with COVID die. However, the old are affected far more than the young – 67% of patients over 80 die compared with only 22% of patients under 40.

Older patients are more affected – Despite the prominence of media reports of young patients dying, only 226 patients making it to discharge or death are aged under 40 years and so far 50 of these patients have died. Regardless of age, most patients were previously able to live without assistance in daily activities which indicates that highly dependent patients are simply not admitted to intensive care in the UK. It is still worth noting that COVID is more deadly for the younger population than ‘normal’ non-COVID viral pneumonia.

Patients of black and Asian heritage are disproportionately affected: According to the 2011 census, Asian ethnic heritage makes up 7.5% of the UK population but comprise 15% of COVID cases admitted to intensive care; black ethnic heritage makes up 3.3% of cases but over 11% of COVID cases admitted to intensive care. It is worth noting that this contrasts sharply with non-COVID viral pneumonia admissions where people of black and Asian heritage are slightly under-represented in intensive care admissions. We wonder is it because these groups have higher rates of diabetes and other serious diseases, or are there other fundamental reasons? 

Severe previous disease is a clear risk factor: A no-brainer really, but patients without commodities face a 50/50 chance of recovery sufficient to be discharged from intensive care. Patients with severe previous diseases – for instance – metastatic cancer, immunocompromise from steroids or HIV, kidney dialysis, or liver cirrhosis – the chances fall to only 39% recovering sufficiently to make it out of intensive care. Death rates in the morbidly obese are about 9% greater than in patients with a normal weight. This last group is really difficult since it is difficult or impossible to nurse these patients in prone positions which seems to be especially advantageous in COVID.

Requiring advanced respiratory support or kidney replacement therapy are especially poor prognostic signs – Again a no-brainer but I admit to being slightly surprised that the statistics were as good as reported here. Requiring advanced respiratory support – i.e., intubation and ventilation - has a mortality of 67% versus only 20% of patients requiring lower levels of respiratory support, such as oxygen by face mask or CPAP. 80% of patients requiring dialysis die. Clearly ventilation has a role, but we also need to be realistic that it is not a case of ventilating patients until they clear their lungs – based on these numbers most of these patients will die.

For those who have made it this far, the summary is short: if you need admission to intensive care then it is 50/50 whether you survive to get discharged back to a ward. In reality, we expect many patients with severe COVID to be left with permanent damage to their lungs, as was seen with other coronavirus diseases SARS and MERS.

For those interested in reading further, this data is from the ICNARC Case Mix Programme Database. The Case Mix Programme is the national clinical audit of patient outcomes from adult critical care coordinated by the Intensive Care National Audit & Research Centre (ICNARC). For more information on the representativeness and quality of these data, please contact ICNARC.