Immune effector cell-associated neurotoxicity synd, grade 5

This code signifies the most severe form of immune effector cell-associated neurotoxicity syndrome (ICANS), characterized by life-threatening neurological dysfunction. It represents a critical adverse event following immune effector cell therapies, such as CAR T-cell therapy, requiring intensive medical intervention.

Use this code when documentation clearly indicates a patient experiencing grade 5 ICANS, which typically involves death due to neurotoxicity or a severe, irreversible neurological event. This diagnosis is supported by clinical assessment of neurological function, often utilizing the ICANS grading scale, and a temporal relationship to immune effector cell therapy.

• Ensure the medical record explicitly states "grade 5" ICANS or describes a fatal neurotoxic event directly attributed to immune effector cell therapy.
• Do not confuse with other grades of ICANS (G92.01-G92.04), which represent less severe neurological toxicities.
• Sequence this code as a primary diagnosis when it is the reason for the encounter or admission; otherwise, it may be a secondary diagnosis.