Immune-Related Emergencies, CRS, ICANS, and Urgent Triage

Immune-Related Emergencies, CRS, ICANS, and Urgent Triage

Immune therapies can keep working long after the infusion ends, which is part of their benefit and part of their risk. Checkpoint inhibitors, CAR T-cell therapy, tumor-infiltrating lymphocyte therapy, bispecific antibodies, cytokines, and other immune-directed treatments can cause inflammatory toxicity that overlaps with infection, disease progression, embolism, endocrine failure, and medication effects. The RN triage question is simple: could this symptom be immune-related and urgent?

Immune-Related Adverse Events

Immune-related adverse events, or irAEs, can involve skin, bowel, liver, lungs, kidneys, endocrine glands, heart, nervous system, eyes, joints, or blood. Red flags include severe rash, blistering, mucosal lesions, persistent diarrhea, blood in stool, abdominal pain, jaundice, dark urine, new cough, dyspnea, chest pain, palpitations, severe fatigue, dizziness, headache, vision change, weakness, confusion, or decreased urine output. Endocrine emergencies may look like profound fatigue, hypotension, vomiting, dehydration, hypoglycemia, hyperglycemia, or mental status change.

The nurse should assess severity, timing, therapy type, comorbidities, infection exposure, medications, and baseline function. Escalate early because high-grade irAEs may need treatment hold, corticosteroids, hormone replacement, specialty care, imaging, cardiac testing, stool studies, or admission. Do not tell patients to self-start steroids or antidiarrheals unless that is their specific plan from the oncology team.

Cytokine Release Syndrome

Cytokine release syndrome, or CRS, is a systemic inflammatory response most associated with CAR T-cell therapy and bispecific antibodies, though other immune therapies may contribute. Fever is often the first sign. Progression can include rigors, tachycardia, hypotension, hypoxia, capillary leak, renal or liver dysfunction, coagulopathy, and shock. CRS can resemble sepsis; both may be managed urgently while the team evaluates cause.

Nursing actions include frequent vital signs, oxygen saturation, respiratory assessment, mental status checks, intake and output, telemetry if ordered, lab monitoring, cultures and antibiotics if infection is possible, and rapid provider notification. Treatments may include antipyretics, IV fluids, oxygen, vasopressors, tocilizumab, corticosteroids, or ICU care depending on grade and protocol. Fever after cellular therapy or bispecific antibody treatment should be treated as urgent until the care team says otherwise.

ICANS

Immune effector cell-associated neurotoxicity syndrome, or ICANS, is neurologic toxicity after immune effector therapy. Early signs may be subtle: handwriting change, trouble naming objects, word-finding difficulty, tremor, slowed responses, impaired attention, agitation, or mild confusion. Severe ICANS can cause aphasia, somnolence, seizures, motor weakness, cerebral edema, or coma.

Use ordered neurologic tools such as orientation questions, handwriting samples, or immune effector cell encephalopathy scoring when required. Implement seizure and fall precautions, assess swallowing and airway risk, avoid sedating medications unless ordered, and escalate changes promptly. Neurotoxicity can occur with or after CRS, but it can also appear separately.

Urgent Triage and Education

Effective triage starts with identifying the therapy. Ask the patient or caregiver for the treatment card, product name, date of infusion, step-up dose status, and emergency instructions. Teach patients to carry therapy information, avoid driving during restricted periods after cellular therapy, remain near the treating center if instructed, and call immediately for fever, dizziness, shortness of breath, confusion, tremor, speech change, seizure, severe diarrhea, chest pain, or severe rash. The nurse's role is to connect the symptom to the therapy quickly and bring the right team to the bedside or phone call.

Triage Discipline

Immune emergency triage should be conservative because early symptoms are easy to mislabel. A fever after bispecific antibody treatment is not simply a fever until CRS and infection are considered. New diarrhea after checkpoint inhibition is not routine gastroenteritis until colitis, infection, and dehydration risk are assessed. New confusion after cellular therapy is not fatigue until ICANS, sepsis, metabolic problems, and medication effects are considered.

During handoff, include therapy name, date and cycle, time from infusion or step-up dose, baseline neurologic status, vital sign trends, oxygen needs, infection workup, organ symptoms, and whether the cellular therapy or immunotherapy team has been contacted. Caregivers are essential observers and should be included in teaching whenever possible.