The writer is deputy director of the Jameel Institute at Imperial College London

London’s intensive care units are overwhelmed, and those elsewhere in the UK may soon be too. The number of Covid-19 patients arriving in ICUs far exceeds the first wave in April, and those needing life-saving treatment such as mechanical ventilation have exhausted resources. Ambulances are queueing at hospital gates, patients are being transferred hundreds of miles and oxygen supplies are running low.

The most severe shortage is not in beds, but in staff. NHS England has lowered ICU nurse staffing ratios from one nurse per patient to one for every two, and hospitals in the Midlands are being told to dilute their ratios further.

Clinicians are now being forced to make agonising choices about who does and who does not receive care, with consequences for the survival of patients. Research on the first wave last spring found that when ICUs reach full capacity, the chance of a patient dying is 19 per cent higher. Is this decided by a random roll of the dice, or is it based on an assessment of who is at greater risk of dying? How should clinicians decide who gets the limited resources in an overstretched ICU? These are ethical questions that should be addressed by societies through expert committees, not individual clinicians.

Unfortunately, in the UK there is no workable national guidance to help ICU clinicians prioritise care in the present conditions. The Covid-19 guidelines issued by the National Institute for Health and Care Excellence are based on its principle that a clinician should “balance the need to achieve the most overall benefit for the greatest number of people, with the need to ensure fairness and respect for individual choice”. For older Covid patients, Nice recommends the use of a score of clinical frailty “as part of a holistic assessment”. Depending on the outcome of the assessment, the patient is referred to critical, ward-level or end-of-life care.

The Nice guidance is only partly helpful. It avoids the tough question of how to prioritise care with severely curtailed resources, leaving heartbreaking life-or-death decision-making to clinicians. This takes a heavy toll. After the first wave last year, 40 per cent of ICU staff in England reported symptoms of post-traumatic stress disorder, 11 per cent had severe anxiety and 7 per cent were problem drinking. In contrast, PTSD is reported by 17 per cent of recent UK army veterans.

ICU staff are our frontline soldiers in this battle, and we are failing them. Last week, the Nuffield Council on Bioethics published an urgent call for “authoritative and comprehensive” national guidelines. Effective government-issued guidance would be evidence-based and developed by a committee of experts and patient representatives. It would help ease the emotional and legal burden of responsibility on staff, while saving as many lives as possible.

Even under extreme resource constraints, the loss of health and life can be minimised by considering patients’ capacity to benefit from intensive care and focusing on maximising aggregate expected life years. Younger patients, for instance, are more likely to survive the highly invasive life support needed on Covid wards and have longer lives ahead of them. This system of prioritising is a well-established concept in health economics and it should be enshrined in guidance.

Extreme resource constraints also force choices between emergency patients and those whose treatment can be delayed. Many hospitals have ceased performing most non-emergency procedures. My team’s research found that this will have serious repercussions on population health. Blanket policies that prioritise emergency patients lead to more people dying younger than policies that prioritise elective patients with specific diseases including cancer, cardiovascular and digestive diseases. If we want to achieve the greatest benefit for the greatest number of people, we need to free hospital capacity for those with urgent clinical need — at the expense of some emergency patients.

Was this dire situation avoidable? The UK health system went poorly equipped into the pandemic. Spending on healthcare per person grew by an average of 4.7 per cent each year between 1997 and 2009, falling to an average of 1.2 per cent between 2009 and 2018. There is a shortage of about 40,000 nurses. This has affected the Covid response.

In the short term, we can all lower the immense pressure on hospital staff by adhering to the social distancing measures. But this crisis is forcing us to make stark choices. New guidance could save many lives while offering overwhelmed staff reassurance that the decisions they are making are the best ones possible, given the unenviable circumstance.

The article has been corrected to reflect the fact that NHS England sets nurse staffing ratios, not the Royal College of Nursing