Life-threatening immune-related adverse events in the intensive care unit: a narrative review

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment by significantly improving survival across various malignancies. However, they are associated with immune-related adverse events (irAEs), resulting from excessive immune activation. Some irAEs can be life-threatening and require intensive care unit (ICU) management. These toxicities involve cardiovascular, pulmonary, hepatic, gastrointestinal, neurologic, endocrine, and hematologic systems and often occur early in the ICI course. As ICI become increasingly integrated into earlier phases of cancer care, intensivists must be prepared to manage irAEs.

Narrative review objectives: To summarize the evolving evidence on the epidemiology, diagnosis, and management of severe irAEs requiring intensive care by looking for the most relevant articles up to August 2025. The review emphasizes (1) the rationale and timing for immunosuppression beyond corticosteroids, (2) the integration of hemodynamic and organ support strategies, and (3) the importance of multidisciplinary coordination between oncology and critical care teams.

Early recognition, structured diagnostic evaluation, and multidisciplinary management are key to optimizing outcomes. Although overall mortality remains high-particularly in myocarditis and multisystem involvement-timely diagnosis and individualized immunosuppressive therapy can improve survival. Rechallenge with ICIs may be cautiously considered in selected patients after full clinical recovery and comprehensive risk assessment. This review aims to support intensivists facing this emerging clinical scenario by synthesizing current evidence and practical strategies for balancing immune modulation with oncologic efficacy in the ICU setting.