6.5 Hematology, Immunology & Oncology

Hematology, Immunology & Oncology

Progressive care nurses regularly manage patients whose blood counts, clotting cascade, or immune system have become the primary threat to survival — whether from anticoagulation gone wrong, an autoimmune attack on the nervous system, or a cancer treatment complication that turns into a true emergency.

Anemia and Coagulopathy

Anemia in critical illness may result from acute blood loss, chronic disease, nutritional deficiency, or hemolysis; transfusion decisions weigh the hemoglobin trend, symptoms (tachycardia, hypotension, dyspnea), and comorbidities rather than a single fixed number.

Medication-induced coagulopathies are common and dangerous:

• Warfarin (Coumadin) prolongs the INR; reversal for serious bleeding uses vitamin K plus prothrombin complex concentrate (PCC) for rapid factor replacement.
• Antiplatelet agents (aspirin, clopidogrel, ticagrelor) impair platelet aggregation and increase bleeding risk without affecting the INR.
• Direct oral anticoagulants (DOACs) such as apixaban and rivaroxaban do not reliably prolong the INR either, so a normal INR cannot be used to assume it is safe to proceed with an invasive procedure in a patient taking one; timing of the last dose and renal function matter more than routine coagulation labs.
• Heparin-induced thrombocytopenia (HIT) is an immune-mediated reaction typically appearing 5–10 days after heparin exposure, marked by a platelet drop of more than 50% from baseline, paradoxically accompanied by a high risk of new clot formation. The critical nursing action is to stop all heparin exposure immediately, including heparin flushes and heparin-coated catheters, and transition to a non-heparin anticoagulant such as argatroban or bivalirudin; platelet transfusion is generally avoided because it can fuel further clotting.

Disseminated intravascular coagulation (DIC) is a distinct and more chaotic coagulopathy, triggered by sepsis, trauma, obstetric emergencies, or malignancy, in which widespread activation of the clotting cascade consumes platelets and clotting factors faster than the body can replace them. The result is simultaneous microvascular clotting and uncontrolled bleeding — oozing from IV sites, petechiae, and organ dysfunction from fibrin deposition in the microcirculation. Laboratory findings classically show a falling platelet count and fibrinogen, prolonged PT/PTT, and an elevated D-dimer. Because DIC is always secondary to another process, treatment is aggressive management of the underlying trigger alongside supportive replacement of platelets, fresh frozen plasma, and cryoprecipitate as clinically indicated.

Autoimmune Disorders

Several autoimmune conditions land patients in progressive care during acute exacerbation:

• Systemic lupus erythematosus can cause multi-organ involvement including nephritis, serositis, and hematologic abnormalities during a flare.
• Guillain-Barré syndrome produces an ascending, symmetric flaccid paralysis following an antecedent infection; the priority nursing concern is respiratory failure from diaphragmatic weakness, monitored with serial forced vital capacity (FVC) and negative inspiratory force measurements — a declining FVC is an indication for intubation before the patient decompensates acutely.
• Amyotrophic lateral sclerosis (ALS) causes progressive motor neuron degeneration affecting speech, swallowing, and respiration, requiring proactive discussion of ventilatory support and goals of care.
• Multiple sclerosis (MS) exacerbations involve demyelination causing variable sensory, motor, and visual deficits, sometimes treated with high-dose corticosteroids during an acute flare.

Blood Product Administration and Plasmapheresis

Safe transfusion practice requires independent two-person verification of patient identity and product, baseline vital signs, close monitoring during the first 15 minutes (when most severe reactions occur), and immediate cessation of the transfusion with maintenance of IV access if a reaction is suspected. Plasmapheresis removes and replaces plasma to filter out pathologic antibodies or immune complexes and is used in conditions such as Guillain-Barré syndrome and myasthenic crisis; nursing care includes monitoring the vascular access, electrolytes, and coagulation status, since the citrate anticoagulant used in the circuit can lower ionized calcium.

Oncologic Emergencies and Neutropenic Precautions

Tumor lysis syndrome occurs when rapid destruction of malignant cells, often after chemotherapy, releases intracellular contents faster than the body can clear them, producing hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia — a combination that can precipitate life-threatening arrhythmias and acute kidney injury. Prevention includes aggressive IV hydration and, in high-risk patients, a uric-acid-lowering agent before treatment begins.

Patients with neutropenia, from chemotherapy or hematologic malignancy, have blunted infection responses — fever may be the only sign of a serious infection — and require neutropenic precautions: private room, strict hand hygiene, avoidance of fresh flowers and raw produce, and prompt broad-spectrum antibiotics for any fever, treated as an emergency. Febrile neutropenia is generally defined as a single temperature at or above 38.3°C (101°F), or 38.0°C sustained over an hour, combined with an absolute neutrophil count below 500 cells/mm³ — this combination triggers immediate cultures and antibiotics, typically within one hour of recognition, without waiting for culture results. Other oncologic emergencies include spinal cord compression (new back pain with neurologic changes) and superior vena cava syndrome (facial or upper-extremity swelling from tumor compression). Finally, when a patient refuses blood products for religious or personal reasons, such as a Jehovah's Witness patient, the nurse's role is to honor documented wishes, ensure informed consent is current, and collaborate with the team on bloodless-medicine alternatives such as cell salvage, erythropoietin, and volume expanders where the patient's directive allows.