0071643192.pdf

RENAL AND GENITOURINARY

EMERGENCIES

■ Suspect rhabdomyolysis if urine is dip positive for heme, but negative
for RBCs.

TREATMENT

■ Treat underlying precipitating cause or discontinue offending agent.
■ N-Acetylcysteinemay help prevent ATN in high-risk patients receiving
radiocontrast agents.
■ Administer crystalloid, mannitol, and alkalinize urine if pigment induced.
■ Renal function typically recovers over days to weeks.

VASCULARDISEASE

Vascular disease of the kidney may be macrovascular (eg, renal artery occlu-
sion, AAA) or microvascular (eg, embolus, malignant hypertension, hemolytic
uremic syndrome, TTP). Hemolytic uremic syndrome (HUS) will be dis-
cussed further.

HEMOLYTICUREMICSYNDROME

Hemolytic uremic syndrome is a disease characterized by microangiopathic
hemolytic anemia, thrombocytopenia, and acute renal failure. It is one of the
most common causes of acute renal failure in children under the age of five.
Thrombotic thrombocytopenic purpura is similar in pathophysiology, but
occurs primarily in adults and characteristically has prominent neurologic
involvement (vs renal involvement in HUS).

ETIOLOGY

HUS most commonly occurs following infection with Escherichia coli
serotype O157:H7. Other infectious agents and toxins have also been impli-
cated including Shigella,Salmonella,Campylobacter, and Yersinia.

SYMPTOMS/EXAM

■ Prodrome of fever, vomiting, abdominal pain, and diarrhea (often bloody)
■ Onset of pallor with petechial or purpural rash
■ Decreased urinary output
■ CNS symptoms (minority of patients): Stroke, seizures, coma

DIAGNOSIS

■ Anemia (Hgb <8 g/dL) and thrombocytopenia
■ PT and PTT normal
■ Renal failure
■ Peripheral smear: Schistocytes

TREATMENT

■ Treat complications of acute renal failure (dialysis as needed).
■ Careful rehydration
■ PRBC transfusion if Hgb < 6 g/dL)
■ Platelet transfusion only if significant bleeding or need for invasive procedure
■ Plasma exchange if CNS symptoms

HUS = microangiopathic

hemolytic anemia,

thrombocytopenia, and acute

renal failure.

HUS most commonly follows

infection with E. coli serotype

O157:H7.

A history of abdominal pain

and diarrhea is common.