What is the hallmark lab pattern of tumor lysis syndrome?

The correct answer is High K, phosphate, uric acid; low calcium.

What new symptom triad signals spinal cord compression in bone metastases?

The correct answer is Back pain, weakness, bowel or bladder changes.

Hematological & Oncology · Topic 4 of 16

Oncologic Emergencies

A patient with lung cancer suddenly can't lie flat and their face is swollen and dusky — this isn't a chemo side effect.

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Overview

Oncologic emergencies are acute, potentially fatal complications of the cancer itself or its treatment. Four high-yield patterns dominate NCLEX: superior vena cava (SVC) syndrome from tumor compression obstructing upper-body venous return; tumor lysis syndrome (TLS) from rapid cancer-cell destruction after chemotherapy; spinal cord compression from vertebral metastasis; and hypercalcemia of malignancy. Each has a recognizable fingerprint, and the nurse's priority is to recognize the pattern and escalate immediately.

Interpretation

Match the fingerprint to the emergency. TLS is a lab pattern; SVC syndrome and spinal cord compression are clinical pictures; hypercalcemia of malignancy is a high calcium with neuro and organ signs. The TLS cascade below shows how rapid cell death drives the lethal endpoints of kidney injury and dysrhythmia.

Tumor lysis cascade

Rapid cancer-cell deathAfter chemo in high-tumor-burden cancer
Intracellular contents releasedHyperkalemia, hyperphosphatemia, hyperuricemia, hypocalcemia
Acute kidney injury + cardiac dysrhythmiasLethal endpoints

During — Monitoring

Serum potassiumK+ rising / > 6.0 mEq/L

Hyperkalemia is the most immediately lethal TLS abnormality

Cardiac rhythm Hallmark

Peaked T waves and widened QRS signal hyperkalemia

Serum phosphorus

Serum calcium

Falls as phosphorus rises; watch for muscle cramps and twitching

Uric acid

Serum creatininerising creatinine

Rising creatinine signals tumor-lysis acute kidney injury

Motor strength and sensation

Serial neuro checks for evolving cord compression

Bladder function

New urinary retention is an autonomic red flag

Technique

Position patient in high Fowler's

First action for suspected SVC syndrome to ease venous return and dyspnea

Apply supplemental oxygen

Supports SVC syndrome and respiratory distress

Give prophylactic IV hydration

Aggressive fluids protect kidneys before and during chemo in high-tumor-burden cancers

Administer allopurinol prophylactically

Given before chemo to limit uric acid formation

Administer rasburicase for established hyperuricemia

Used to lower markedly elevated uric acid in active TLS

Treat hyperkalemia emergently

Peaked T waves (e.g., K+ 6.8) require emergent treatment

Patient Teaching

Report new or worsening back pain

Especially with known bone metastases

Report new leg weakness or trouble walking

Report new bladder or bowel changes

Report facial swelling or fullness

Report breathing that worsens when lying flat

Report muscle cramps after chemotherapy

Early clue to tumor lysis hypocalcemia and hyperkalemia

Report Nowescalate immediately

Facial edema with neck vein distension and dyspnea Hallmark

SVC syndrome; dusky face worse lying flat

New back pain with leg weakness and urinary retention Hallmark

Spinal cord compression; any delay risks permanent paralysis

Hyperkalemia with peaked T waves after chemoK+ > 6.0 mEq/L

Tumor lysis dysrhythmia risk

Rising creatinine after chemotherapy

Tumor-lysis acute kidney injury

High calcium with new confusion

Hypercalcemia of malignancy needing aggressive IV fluids

Clinical Pearl

TLS labs go UP-UP-UP-down: Uric acid UP, Potassium UP, Phosphate UP, Calcium DOWN. If those four hit together after chemo, think tumor lysis.

Oncologic Emergencies

A patient with lung cancer suddenly can't lie flat and their face is swollen and dusky — this isn't a chemo side effect. It's a life-threatening oncologic emergency requiring immediate intervention.

Oncologic emergencies are acute, potentially fatal complications caused by the cancer itself or its treatment. Three high-yield emergencies dominate NCLEX testing. Superior vena cava (SVC) syndrome occurs when a tumor (usually lung cancer or lymphoma) compresses the SVC, obstructing venous return from the head and upper body. Signs include facial and periorbital edema, neck vein distension, dyspnea worse when lying flat, and a dusky or plethoric appearance of the face and upper chest. This is a medical emergency requiring upright positioning, oxygen, and emergent notification. Tumor lysis syndrome (TLS) results from rapid cancer cell destruction — often 12–72 hours after initiating chemotherapy for high-tumor-burden cancers like leukemia or lymphoma. Dying cells release potassium, phosphate, and uric acid into the blood. The hallmark lab pattern is hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia. Cardiac dysrhythmias and acute kidney injury are the lethal risks. Aggressive IV hydration and allopurinol are given prophylactically. Spinal cord compression presents with new back pain, motor weakness, and bowel or bladder changes in a patient with known bone metastases. This is a neurological emergency — delays beyond 24–48 hours risk permanent paralysis. The nurse's priority is recognizing the triad and reporting immediately.

Key Distinctions

Don't confuse TLS (caused by cancer cell death releasing intracellular contents) with sepsis from neutropenia — TLS has a specific lab fingerprint (high K+, high phosphate, high uric acid, low calcium) while neutropenic sepsis presents with fever and infection signs. Students mix up SVC syndrome (upper body edema, facial plethora) with cardiac tamponade (Beck's triad: hypotension, muffled heart sounds, JVD) — both cause JVD, but SVC syndrome has prominent facial swelling that tamponade does not.

Clinical Pearl

TLS labs go UP-UP-UP-down: Uric acid UP, Potassium UP, Phosphate UP, Calcium DOWN. If those four hit together after chemo, think tumor lysis.

Knowledge Check

3 quick questions on the must-knows for this topic.

Question 1 of 3

What positioning helps a patient with superior vena cava syndrome?

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Overview

Interpretation

During — Monitoring

Technique

Patient Teaching

Oncologic Emergencies

A patient with lung cancer suddenly can't lie flat and their face is swollen and dusky — this isn't a chemo side effect. It's a life-threatening oncologic emergency requiring immediate intervention.

Key Distinctions

Clinical Pearl

Knowledge Check

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