Sometimes the most serious oncologic emergencies present very benignly: a slow nose bleed (portending DIC), a low grade fever (neutropenic bacteremia), vague weakness/fatigue (an undiagnosed leukemia)…

The triage nurse calls you out to triage to evaluate a patient as the resus resident. He is concerned because the patient is complaining of “I can’t walk straight,” and wants to know if you want a stroke team activation, or if they can be evaluated on the teams. The rest of the story isn’t that interesting. He’s been feeling more fatigued and grossly weak over the last three weeks, and over the last two days it’s been to the point where he feels unsteady on his feet. He endorses a dull headache, but his review of systems is otherwise negative. He’s slightly tachycardic (102), afebrile (37.8), not hypoxic (95%), and “normotensive” (138/82). Your neuro exam is non-focal. His coordination is intact and his gait is slow, but narrow based and not lateralizing. You put him in acute, talk to the team, drop a quick note, and keep and eye on his chart. About an hour later, you flip back to the chart, see a new set of vital signs (SpO2 91%) and a critical lab value: WBC 122,000.

Acute leukemia can present insidiously, with vague symptoms and an unsatisfying exam–they don’t always look sick, yet. The rest of the CBC and differential show that he is pancytopenic otherwise, and has a blast percentage of 98%.  This is blast crisis, a true emergency. You call hematology to get them on-board immediately (he will require induction chemotherapy right away), and call the lab to get that BMP back faster (tumor lysis syndrome?). Now it’s time to accelerate his work-up. The chest X-ray shows diffuse infiltrates: likely a consequence of leukostasis, or hyperviscosity syndrome–clumps of immature white blood cells plugging capillary beds. It can cause pulmonary trouble as well as CNS dysfunction, renal injury, and cardiovascular ischemia from the same mechanism.

Treatment requires leukopheresis (+/- induction chemotherapy). To get this ball rolling, call hematology immediately. It requires equipment (and a tech) that we don’t own and may need to be brought in from the NY Blood Center. Leukopheresis is a process by which the blood is run through a machine to filter the immature cells. It requires substantial access with a hemodialysis (“Shiley”) catheter.

Broad spectrum antibiotics are crucial. The leading cause of death in blast crisis is infection. These patients are functionally neutropenic (despite that dysfunctional white count). Resist the urge to transfuse these patients (or replace specific blood components–except in life threatening bleeding) without speaking with hematology first. If tumor lysis syndrome is present, treat appropriately: fluids, allopurinol, rasburicase. Keep an eye on the potassium especially, and manage other electrolyte derangement appropriately.

June 2024