0071643192.pdf

RENAL AND GENITOURINARY

EMERGENCIES

Postrenal Acute Renal Failure

CAUSES

Results from obstruction at any level of the urinary tract:

■ Urethral obstruction:Phimosis or stricture

■ Bladder obstruction:BPH, stones, clot, tumor, neurogenic bladder, poste-

rior urethral valve

■ Intrarenal/ureteral obstruction:Kidney stone, crystalline precipitation,

tumor, iatrogenic, papillary necrosis

SYMPTOMS/EXAM

■ Vary with underlying cause

DIAGNOSIS

■ Renal ultrasound to confirm presence of upper or lower tract obstruction

■ Urine indices and BUN/Cr ratios are typically unhelpful.

■ Urinalysis is often normal.

■ Obtain retrograde urography if bilateral ureteral obstruction is suspected.

TREATMENT

■ Relieve obstruction (eg, Foley for bladder outlet obstruction).

■ Correct electrolyte imbalances.

■ Dialyze as needed.

CHRONIC RENAL FAILURE

Chronic renal failure is a wide spectrum of disease defined as permanent loss

of renal function of >3 months’ duration. It is staged based on the estimated

glomerulofiltration rate (GFR). End-stage renal disease (ESRD, now termed

kidney failure) is the final endpoint where GFR is <10% and clinical symp-

toms of uremia will ensue without dialysis or transplant.

SYMPTOMS/EXAM

■ Symptoms of uremia are often nonspecific, including anorexia, nausea,

and vomiting, declining mental function.

■ Uremic frost

■ Deposition of urea from evaporated sweat

■ Fine white powder on skin

■ Volume overload/pulmonary edema

■ Hypertension

■ Renal osteodystrophy

■ Due to loss of Vitamin D 3 production and secondary hyperparathyroidism

■ Bone pain, muscle weakness, fractures

■ Pericarditis

■ Suspect tamponade in anyill-appearing patient with ESRD.

■ Early tamponade may manifest as hypotension during dialysis.

■ Systemic calcification

■ Occurs when calcium-phosphate product (Ca2+×PO 4 ) is >70–80

■ Deposition of calcium in joints (pseudogout) or small vessels (ischemia

and necrosis)

■ Anemia

■ Normocytic, normochromic

■ Due to decreased erythropoietin production and RBC survival time