Cytokine release syndrome, grade 5

This code represents the most severe, fatal form of cytokine release syndrome (CRS), a systemic inflammatory response often triggered by immunotherapy, particularly CAR T-cell therapy. It signifies an overwhelming and uncontrolled release of pro-inflammatory cytokines leading to multi-organ failure and death.

Use this code when documentation explicitly states a diagnosis of cytokine release syndrome and specifies a grade of 5, indicating a fatal outcome directly attributable to CRS. This is typically seen in patients undergoing novel immunotherapies where CRS is a known, albeit rare, severe complication.

• Ensure documentation clearly links the patient's death to cytokine release syndrome.
• Do not use this code for other grades of CRS; specific codes exist for grades 1-4.
• This code should be sequenced as the principal diagnosis if CRS grade 5 is the reason for admission and subsequent death, or as a secondary diagnosis if it complicates another condition leading to death.