When the coronavirus pandemic began, the UK scrambled to get more ventilators for intensive care. But now some doctors are trying to keep people off ventilators as they believe it makes some people with covid-19 worse.
Ventilators are used to treat people with covid-19 when the infection stops them being able to breathe on their own, but the procedure to ventilate someone is invasive and can even be traumatic. Doctors have several options for boosting someone鈥檚 oxygen levels. Less drastic measures include giving patients oxygen by face masks or nasal cannulas, two tubes that sit just inside the nostrils.
Those who are sicker may need to be put on a ventilator, which usually requires being unconscious so a breathing tube can be put down their throat. But this has long been known to carry risks, and recovery can take weeks or even months.
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Initially, people taken to hospital with breathing difficulties due to covid-19 were quickly being put on ventilators. This was partly because of information coming from China that people given face masks and nasal cannulas often deteriorate and need ventilation anyway, says Stephen Brett at Imperial College London. But that was based on anecdotal reports, not systematically collected data, he says.
As doctors have gained more experience with covid-19 patients, some now argue against being too quick to ventilate. One factor has been the high death rate in covid-19 patients put on ventilators, which has been more than 50 per cent in the UK. 鈥淭he success rate reported from Italy and New York was very low,鈥� says Michael O鈥機onnor, who heads critical care at the University of Chicago Medicine.
He believes the high air pressures of ventilation could be worsening lung damage. His unit tries to keep people on nasal cannulas for as long as possible before resorting to ventilation. This can be combined with lying patients on their front for part of the day, which aids breathing.
Concerns are also lessening that face masks and nasal cannulas spread infections, as they blow more virus into the air than ventilators. 鈥淧eople are now feeling that the cross-infection risk is manageable,鈥� says Brett. 鈥淭here鈥檚 a belief among some there鈥檚 a population of people who can be supported non-invasively, but there are some institutions that remain sceptical.鈥�
There are no figures on which approach is more commonly used, but ongoing trials should answer the question of which is best, says Matt Morgan at the University Hospital of Wales in Cardiff. 鈥淪hould we use [ventilation] only at the very end, when the patient is about to stop breathing, or intervene earlier? You don鈥檛 want to do it in the heat of the moment. Until we have trial results we do not know what the best thing to do is.鈥�
Earlier this year there was great concern in the UK over how it could source more ventilators. The country had fewer intensive care beds for its population size than many other developed economies, at about seven per 100,000, compared with 12 for Italy and France, and 30 in Germany.
The UK government told ventilator manufacturers to increase production, and asked a range of other firms to design new models that could be made quickly, placing a provisional order for 10,000 machines from vacuum cleaner manufacturer Dyson.
The Dyson order has now been shelved as demand for ventilators hasn鈥檛 been as great as initial predictions suggested. 鈥淭hey would require further development before they would be ready for clinical testing, and they are not currently required to meet immediate demand,鈥� the UK government said in a .
Hospitals raised their intensive care capacity by cancelling non-urgent operations and using ventilators from operating theatres, and some extra machines have been bought from abroad. But a batch of 250 ventilators from China that arrived last month had to be scrapped as they were badly built, .
The push to fill the predicted ventilator gap has led to new, simpler designs, some of which Brett believes may be useful for low-income countries. 鈥淭here has been some very useful engineering done,鈥� he says.
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