Italy is facing serious challenges, with demand for critical care far outstripping supply. Health officials there are having to make very difficult decisions about who to treat – in the knowledge that deciding not to treat will very likely lead to death.

On Thursday the Italian College of Anesthesia, Analgesia, Resuscitation and Intensive Care, issued guidelines advising doctors how to deploy scarce resources when the need for them is outstripped by the demand of critically ill patients. The guidelines state that priority should be given to those who have, first, “greater likelihood of survival and, second, who have more potential years of life”.

As a result, patients with underlying conditions and elderly patients, who are deemed to stand less chance of surviving the virus, may not be treated in favour of healthier and/or younger people who have more chance of recovery.

In the coming months we may face a similar situation in the UK where we do not have the resources necessary to treat all people who will catch Covid-19. So how do healthcare professionals decide who to treat?

Patients with underlying conditions and elderly patients, who stand less chance of surviving the cornavirus outbreak, are not being treated in favour of younger healthier people who have more chance of recovery

The basic principle being applied in Italy is one we are all familiar with – a form of utilitarianism – which aims at maximising the number of lives saved. This approach does not value any one life over another – all lives are equally valuable – but it does say that we should focus resources where they are likely to save the most lives. This means prioritising for treatment those people who are most likely to benefit from the treatment and recover quickly enough to vacate the bed and allow the next person in. This way, more lives are saved overall.

This may be anathema to those of us, including myself, who intuitively prefer a “first come, first served” queuing system. That seems familiar, impartial, equitable and fair. That may well be the best strategy in normal times – but a pandemic is not normal. It is an emergency, and while emergencies do not call for a suspension of ethics, they do call on us to revisit our priorities – and that will always be horribly uncomfortable.

Consider that the person first in the queue suffering from Covid-19 is an older – but not elderly – person, with an underlying lung condition that means they need critical care. Treatment would not be futile – it might save their life – but to choose to treat them would require an extended period of critical care and the outcome would be uncertain. The next two people in the queue are of similar age and have been hit hard by the virus, but they do not suffer with underlying lung problems. They are more likely to survive.

They also need critical care to get them over the worst effects of the virus, but because they have no underlying health conditions they will pass out of the danger zone faster, meaning that both of them are likely to be saved in less time, and for less resource, than it would take to try to save the first patient. In this scenario, assuming that all three cannot be given critical care, it appears to make sense to treat the person who will take up fewer resources with a more certain outcome and free up the bed faster.

There is something very intuitively plausible about a system that aims to save as many lives as possible. But the way to do this is to do what Italy has done, and prioritise those who are most likely to survive. The knock-on effect is that elderly people and those with underlying health conditions – who are less likely to benefit from treatment and would take longer to see benefits – might not receive treatment. This is a gut-wrenching consequence. It is a conclusion that, ultimately, says some people should be left to die.

But we cannot expect to be comfortable in scenarios like this. This kind of situation places us in a genuinely dilemmatic situation in which we have good reasons to be obliged to try to save all lives, but we are nonetheless forced by circumstance to choose who to try to save. Whatever we choose to do, we will be doing something wrong – and that is a defining feature of a genuine moral dilemma. No one should be comfortable with this kind of conclusion. If we do end up here, by taking this kind of decision we will not win. We will all lose in some way.

It is also worth remembering that the people who would have to make these triage decisions are the clinicians on the frontline. They will have an impossible job, and yet they will do it. These are the people who will bear the brunt of this dilemma – day in, day out – and who will be having to make the decisions that may leave them feeling instinctively that they have done something wrong. They will be facing the families of those who have died or are dying, and explaining to them why they made no effort to save them. This will come at a cost – and that itself requires an ethical response.

When we think about ethics in healthcare, a key principle is avoiding harm and suffering. Here, however, there is no avoiding harm. All we can do is try to mitigate it, and if we cannot mitigate it completely then we need to be understanding and accept – desperately hard though it is – that not everyone can be saved. This is something we already know – we just try not to think about it. In a pandemic like this, however, we cannot help but confront it head on.

• Dr Jonathan Ives is deputy director of the Centre for Ethics in Medicine at the University of Bristol