Table 1.

Comparison of criteria for CRS grades between the Penn, Lee, and ASTCT Scales

Grade	Penn Scale (Porter et al)13	Lee Scale (Lee et al)18	ASTCT (Lee et al)2
Grade 1	• Mild reaction treated with supportive care only	• Symptoms are not life-threatening and require symptomatic treatment only (eg, fever, nausea, fatigue, headache, myalgias, malaise)	• Fever (temperature ≥38°C)
			• No hypotension and/or hypoxia
Grade 2	• Moderate reaction requiring IV therapies or parenteral nutrition	• Symptoms require and respond to moderate intervention	• Fever (temperature ≥38°C)
	• Mild signs of organ dysfunction (creatinine ≤ grade 2 or LFT results ≤ grade 3)	• Oxygen requirement <40%* or hypotension responsive to fluids or low-dose pressors or grade 2 organ toxicity	• Hypotension not requiring vasopressors
	• Hospitalization for CRS or febrile neutropenia		• Hypoxia requiring low-flow (≤6 L/min) nasal cannula† or blow-by
Grade 3	• More severe reaction requiring hospitalization	• Symptoms require and respond to aggressive intervention	• Fever (temperature ≥38°C)
	• Moderate signs of organ dysfunction (grade 3 creatinine or grade 4 LFT results) related to CRS	• Oxygen requirement ≥40% or hypotension requiring high-dose or multiple pressors or grade 3 organ toxicity or grade 4 transaminitis	• Hypotension requiring vasopressors with or without vasopressin
	• Hypotension treated with IV fluids‡ or low-dose pressors		• Hypoxia requiring high-flow (>6 L/min) nasal cannula,† facemask, nonrebreather mask, or Venturi mask
	• Hypoxemia requiring oxygenation, BiPAP, or CPAP
Grade 4	• Life-threatening complications, including hypotension requiring high-dose vasopressors or hypoxemia requiring mechanical ventilation	• Life-threatening symptoms	• Fever (temperature ≥38°C)
		• Requirement for ventilator support or grade 4 organ toxicity (excluding transaminitis)	• Hypotension requiring multiple vasopressors (excluding vasopressin)
			• Hypoxia requiring positive pressure (eg, CPAP, BiPAP, intubation and mechanical ventilation)

BiPAP, biphasic positive air pressure; CPAP, continuous positive air pressure; LFT, liver function test.

^*At 5 L/min, the approximate fraction of inspired oxygen is 40%.

^†Low-flow nasal cannula defined as oxygen delivered at ≤6 L/min. Low flow includes blow-by oxygen delivery, sometimes used in pediatrics. High-flow nasal cannula is defined as oxygen delivered at >6 L/min.

^‡Defined as multiple fluid boluses for blood pressure support.