However, as is unfortunately common with ethical terms in the modern era, it is increasingly common for people advocating their own dubious approaches to allocating medical treatment to give those approaches cover by also calling them 'triage'. 'Triage' in this loose sense does not justify anything; but, of course, that's the sophistry of it -- by calling your scheme of distribution 'triage', even if it is entirely antithetical to triage itself, you can pretend that you require no further justification. You can pretend, as some Italian doctors recently have, that scarcity of resources means you can deny the elderly medicine that can heal them, medicine that they might need more than a younger person with a stronger immune system, because it's a 'triage situation'. It's as morally odious as claiming that it's OK for police to go into the bank with guns blazing because it's a 'hostage negotiation'. The situation may be an emergency, but the proposed solution is neither necessary nor even appropriate for that situation.
In any case, here are some comments I made in 2012 in response to some similar sophistry.
The entire point of triage is that only need is considered. Triage systems were originally developed in a military context when field doctors started giving medical treatment not on the basis of rank but on the basis of need, as determined by purely medical criteria. This is what genuine triage is: it is a system, operating under a scarcity of resources significant enough to require careful discrimination of who actually receives those resources (most clearly in emergency or disaster, but resources do not necessarily have to be anywhere near that scarce to become an issue), where distribution of those resources is done purely on the basis of actual medical need according to established principles that only consider medical issues. Remember, it has always been the case that doctors have had to make hard choices based on scarce resources. Actual triage systems only developed when the principles governing those choices were no longer official rank, social status, subjective assessment, or any other nonmedical criterion. We can call those other resource-management systems 'triage' in a loose sense, but they are radically different for moral purposes, and cannot all be lumped together as if the justification for one were justification for another. Just as genuine triage management cannot, by its nature, be indiscriminate in the use of medical resources, so it cannot, by its nature, take into account anything other than medical need. And precisely the reason why triage is an important ethical as well as medical concept is that it operates in conditions of necessity according to principles wholly geared to dealing with the necessity; it's the medical necessity, and the proportion of means to the end of dealing with that particular necessity, that justifies triage decisions.