Typical features include Hypoxia Widened pulse pressure Increased or decreased cardiac output Increased blood urea nitrogen (BUN), D-dimer, liver enzymes, and bilirubin Low fibrinogen level Grading of cytokine release syndrome (3) is as follows: Grade 1: Symptoms (eg, fever, nausea, fatigue, headache, myalgias, malaise) are not life-threatening and require symptomatic treatment only.