COVID-19, a novel coronavirus, which emerged in China in December 2019 and has since spread around the world, will test healthcare systems to the limit. Between 4 and 5% of infected patients are likely to require hospitalisation, and some 30% of those may need intensive care, including invasive mechanical ventilation. An accurate assessment of health system surge capacity, i.e., the ability of the healthcare system to triage and treat patients at times of large-scale surge in demand for services, is particularly relevant for governments trying to deal with the COVID-19 pandemic.
Elements of surge capacity
Surge capacity has four elements: 1) staff (medical personnel, doctors, nurses, pharmacists), stuff (equipment, supplies), structures (hospitals) and systems (successful coordination and management of various levels of the healthcare system). All elements should be considered together. While it may be possible to build a hospital in 10 days, as we have seen in China, or commandeer a school or exhibition hall for a hospital facility, a building on its own is useless unless you have the healthcare staff and medical equipment to support the newly-created hospital beds.
- In terms of medical staff, countries that already have severe staff shortages (such as the UK which has 106,000 vacancies, 44,000 of those in nursing, in NHS England alone) will likely fare worse in dealing with COVID-19.
- It takes a long time to train medical staff and the only limited mitigation measures countries have at their disposal are to call back to duty recently-retired doctors and nurses, to allow final-year medical students to graduate earlier and join the workforce, or to get medical staff from other specialities to work in intensive care. However, the latter would require extensive training.
- To deal with COVID-19 complications, intensive care beds, particularly those equipped with ventilators are required. There is a great disparity between countries in this regard.
- The UK is quite low in terms of acute care bed numbers. Based on 2012 data, the UK had about 4,100 critical care beds. Compared with other European countries the UK ranked 23rd of 31 in terms of intensive care beds capita and 29th of 31 for all hospital beds per capita. Data from 2017 suggest most intensive care units in UK were running at or above 90% occupancy – suggesting insufficient provision even before COVID-19 pandemic. The latest data for the UK suggests 4,000-5,000 intensive care beds are currently operational, but of them 3,500 are already occupied by other patients.
- A potential solution to reduce pressure on beds is to discharge patients in other parts of the hospital to social services in order to allow hospitals to move intensive care patients quicker into low-dependency hospital beds.
- Another option is to postpone non-emergency surgery – the UK is doing that from 15 April, while several other countries have announced similar plans – however, such measures have significant repercussions for other patients as some emergency surgical procedures may also be delayed, particularly if doctors and nurses fall ill.
- Therefore, one impact of COVID-19 is that we will see a surge in deaths from other causes as health systems are stretched to the limit.
Disparate outcomes in mortality based on each country’s surge capacity
We should not be underestimating the challenge – Italy which has the 10th highest number of critical care hospital beds in Europe saw its heath system crumble under pressure, so other countries with less capacity would struggle even more. In comparison, Germany, with around 28,000 intensive care beds, of which 25,000 are equipped with ventilators, has about four times the per capita bed capacity of the UK. Globally, countries like Japan, South Korea, Germany, Austria will do relatively well in saving the lives of patients critically ill with COVID-19, while those further down the international ranking, like the UK, Sweden, Chile, Canada and Mexico, would likely do worse in terms of saving lives.
Furthermore, there is a limit to how much ventilator production capacity can increase. For example, Italy expects to increase the number of ventilators produced per month by its sole domestic manufacturer from 125 to 500 by relying on military help, but this would be still insufficient to meet demand. In the UK, where manufacturers in other industries have been asked to step in, the Make UK engineering trade body has warned there could be difficulties with sourcing imported electronics components, given the unprecedented global rise in demand.
Inadequate surge capacity makes virus suppression measures essential
The key takeaway message is that countries do and should take into account their health system surge capacity when planning what measures to take and when. For the UK and US a recent study from Imperial College suggests with that the healthcare system capacity will be exceeded by between 8 and 30 times: capacity will be exceeded by 30 times if you do nothing and will exceeded by 8 times if you impose the “optimal” mitigation scenario which is a combination of case isolation, home quarantine, school closure and social distancing of those most at risk. With optimal mitigation the study forecasts that deaths will be cut in half compared to the ‘do nothing’ scenario, but, even if all patients requiring care were treated In addition, even if all patients were able to be treated, we are still looking at 250,000 deaths in the UK, and 1.1-1.2 million deaths in the US. Considering that health system capacity will be exceeded significantly, the Imperial College study suggests that suppression measures – the type that completely or partially shut down the economy – will also be required for a time, in addition to the mitigation measures. The difference between optimal mitigation and combining it with suppression will be measured in 10s of thousands of lives saved and that calculation will affect countries as they decide when and for how long to shut down the economy and if and when to bring back mitigation and/or suppression strategies as cases start to increase again once initial measures are lifted.