is initiated. Loop diuretics (furosemide) can also be given

in a dose of 40-80 mg IV. Bisphosphonates may also be

used, but their maximum effect does not occur for

2-4 days. Hemodialysis may be indicated in severe cases.

Cancer patient in ED

Identify signs, symptoms, risk factors for

specific cancer-related complications

PE, malignant

effusion

Hypercalcemia, tumor Wea kness, arrhythmia, lysis syndrome, CNS �+----� f infection or metastasis AMS, ever

svc syndrome Upper trunk, facial

edema

Consider non-cancer-related illness

or complication

.A. Figure 70-1. Oncologic emergencies diag nostic algorithm. AMS,

altered mental status; CNS, central nervous system; ED, emergency

depa rtment; PE, pulmonary embol ism; SVC, superior vena cava.

CHAPTER 70

Tumor lysis syndrome is treated with IV hydration (NS),

loop diuretics, and allopurinol. Hyperkalemia remains the

most dangerous component of tumor lysis syndrome,

causing life-threatening dysrhythrnias. Hemodialysis may

be needed in patients with renal failure, severe electrolyte

abnormalities, or fluid overload.

If not treated in the first 48 hours, the mortality for

neutropenic sepsis approaches 50%. The prompt administration of empiric antibiotic therapy has resulted in a

decrease in mortality to 1 0%. Neutropenic fever should be

treated expeditiously with ceftazidirne 2 g IV. Vancomycin

should be added for patients with sepsis, known methicillin-resistant Staphylococcus aureus, or indwelling venous

catheters.

DISPOSITION

..... Admission

Patients with acute spinal cord compression will often

require intensive care unit (ICU) admission for frequent

neurologic evaluation. Neutropenic patients may also

require an ICU if they have signs of sepsis or septic shock.

If admitted to the floor, they should have reverse isolation

precautions to protect them from hospital acquired infections. Patients with renal failure or severe electrolyte

abnormalities will require an ICU or telemetry monitored bed.

..... Discharge

Cancer patients with a febrile illness who are not neutropenic may be considered for discharge depending on the

source of the fever. Patients with mild dehydration and

correctable electrolyte abnormalities may also be considered for discharge.

SUGGESTED READING

Blackburn P. Emergency complications of malignancy. In: Tintinalli

JE, Stapczynski JS, Ma OJ, Cline DM, Cydulka RK, Meckler GD.

Tintinalli's Emergeno/ Medicine: A Comprehensive Study Guide.

7th ed.New York, NY: McGraw-Hill, 2011, pp. 1 508-1516.

McCurdy MT, Shanholtz CB. Oncologic emergencies. Grit Care

Med. 201 2;40:22 12-2222.

Sickle Cell Emergencies

Brian R. Sellers, MD

Amy V. Kontrick, MD

Key Points

• Control pain aggressively.

• Search for and treat the precipita nts of

pain crisis.

INTRODUCTION

Sickle cell disease (SCD) is an inherited chronic disease

found primarily in those of African, Middle Eastern,

Indian, or Mediterranean ancestry. SCD is characterized by

a defect in the hemoglobin molecule, which normally consists of two pairs of a and p globin. A single amino acid

substitution (valine for glutamine) on the P-globin gene

results in sickle hemoglobin (Hb S). The mutation that

causes the amino acid substitution is inherited as an auto ­

somal recessive trait. Patients with sickle cell trait have one

abnormal P-globin gene (heterozygous HbAS), whereas

those with SCD have 2 abnormal P-globin genes (homozygous HbSS). During states of biologic stress (eg, low 02

state, infection, dehydration, pregnancy, cold exposure,

trauma) the Hb S polymerizes, resulting in deformation

(sickling) of the red blood cell (RBC). This sickled RBC has

reduced ability to pass through small blood vessels, resulting in vasoocclusion, hemolysis, and end-organ damage.

Premature destruction of the sickled RBC results in a

shorter than normal life span of the cell.

Two million people in the United States have sickle c ell

trait, and 70,000 have sickle cell disease. Although survival

has improved dramatically recently, life expectancy of

patients with SCD is shorter than average, now just greater

than 50 years.

Most patients with SCD present to the emergency

department (ED) with either a painful vase occlusive crisis

• Complications of sickle cell disease, both typical and

atypical, must be aggressively sought after and treated.

• Have a low threshold for admission when patients may

have an occult infection.

or sequela from vase-occlusion, some of which may be lifethreatening. It is the role of the emergency physician to not

only control pain but also diagnose and treat potential life

threats. Acute sickle cell emergencies can be divided into

several classifications: acute pain crisis, acute chest syn ­

drome, infection, neurologic, splenic sequestration, aplastic crisis, hemolytic anemia, and priapism.

..... Acute Pain Crisis

Vase-occlusive pain crises account for approximately 90% of

ED visits. Severe back and extremity pain results from microinfarction of the bones and joints. Abdominal pain crises

result from ischemia to the mesentery, spleen, and liver.

..... Acute Chest Syndrome

Acute chest syndrome is the most common cause of death

in patients with SCD. Although it is more common in

children, it is more severe in adults. Acute chest syndrome

is characterized by fever, chest pain, respiratory symptoms, hypoxia, and an infiltrate seen on chest x-ray

(CJCR). It is a result of pulmonary ischemia and infarction. Acute chest is frequently a complication of pneumonia. Chlamydia and Mycoplasma are the 2 most common

organisms, but viruses, Streptococcus pneumoniae,

Staphylococcus aureus, and Haemophilus influenzae are all

potential causes.

299

CHAPTER 71