Table 2 Examples of the application of criteria found in the screening instruments in the allocation of mechanical ventilators

Clinical criteria

“Save more lives”

Instruments with exclusion [18,19,20,21, 23, 25, 27, 29,30,31,32]

Patient A: 26 years old, affected by severe trauma, with respiratory failure.

Patient B: 65 years old, without comorbidities, diagnosed with COVID-19 and with respiratory failure.

The resource would be allocated to patient B as a result of patient A’s poor prognosis and the high probability of death. Severe trauma is an exclusion criterion in most instruments.

“Save more lives”

Instruments without exclusion (multiple principles) [22, 26]

Patient A: 49 years old with mild COPD, benzodiazepine intoxication and respiratory failure, SOFA score: 4.

Patient B: 61 years old, with severe Alzheimer’s disease, chronic renal failure and on dialysis, and diagnosis of COVID-19 with respiratory failure, SOFA score: 10.

Patient C: 64 years old, without comorbidities, with 60% of the body area injured by 2nd and 3rd degree burns, with sepsis, multiple organ failure and respiratory failure, SOFA score: 12: 12.

The resource would be given to Patient A, to the detriment of Patients B and C, who had lower prioritization due to the short and long term prognosis and life cycle.

Despite health conditions and severe comorbidities, all patients are included in the screening protocol.

Non-clinical criteria

“Equity”

Life cycle [21]

Patient A: 75 years old. No comorbidities, diagnosis of COVID-19 with respiratory failure. SOFA: 6.

Patient B: 45 years old. No comorbidities, diagnosed with COVID-19 and respiratory failure, SOFA: 6.

Patient B would have a higher priority to receive the resource, based on the logic that everyone should have the same opportunity to live all the cycles of life.

Tiebreaker criteria

“Equality”

Ballot [17, 21, 22, 26, 31, 32]

Patient A: 20 years old, without severe comorbidities, diagnosed with COVID-19 with respiratory failure, SOFA score 7.

Patient B: 39 years old, diagnosed with COVID-19 with respiratory failure, without severe comorbidities. SOFA 7.

Patients had the same priority score, both in terms of prognosis and life cycle (0–49 years). The resource would be allocated based on chance, in a fair and transparent way.