Table 3 Summary of grading systems of CRS

CTCAE (Symptoms and Signs)

Fever with or without constitutional symptoms

Hypotension responding to fluids; hypoxia responding to < 40% O2

Hypotension managed with one pressor; hypoxia requiring ≥ 40% O2

Life-threatening consequences; urgent intervention indicated

Death

Lee’s criteria (Symptoms and Signs)

(i) Symptoms are not life-threatening and require symptomatic treatment only,

(i) Symptoms require and respond to moderate intervention

(ii) Oxygen requirement < 40%

(iii) Hypotension responsive to fluids or low dose of one vasopressor

(iv) Grade 2 organ toxicity

(i) Symptoms require and respond to aggressive intervention

(ii) Oxygen requirement ≥ 40%

(iii) Hypotension requiring high dose or multiple vasopressors

(iv) Grade 3 organ toxicity or grade 4 transaminitis

(i) Life-threatening symptoms

(ii) Requirement for ventilator support

(iii) Grade 4 organ toxicity (excluding transaminitis)

Death

Treatment recommendation

Supportive care

Supportive care or supportive care + Tocilizumab ± corticosteroids

Supportive care + Tocilizumab ± corticosteroids

Supportive care + Tocilizumab ± corticosteroids

N/A

Fever

Temperature ≥ 38 °C

Temperature ≥ 38 °C

Temperature ≥ 38 °C

Temperature ≥ 38 °C

Death

With

Hypotension

None

Not requiring vasopressors

Requiring a vasopressor with or without vasopressin

Requiring multiple vasopressors (excluding vasopressin)

Death

And/Or

Hypoxia

None

Requiring low-flow nasal cannula or blow-by

Requiring high-flow nasal cannula, facemask, nonrebreather mask, or Venturi mask

Requiring positive pressure (e.g., CPAP, BiPAP, intubation, and mechanical ventilation)

Death