0071643192.pdf

RENAL AND GENITOURINARY

EMERGENCIES

DIFFERENTIAL

■ Includes renal artery stenosis, cyclosporine or tacrolimus toxicity,
obstruction, UTI

DIAGNOSIS

■ Suggested in setting of elevated BUN/Cr
■ Allograft biopsy is definitive.
■ Rule out other causes with UA, immunosuppressant levels, renal ultrasound.

TREATMENT

■ High-dose steroids
■ Antibody preparations directed at attacking T lymphocytes causing allo-
graft rejection (eg, OKT3)

NEPHROLITHIASIS

Types of stones (see Table 18.6):

■ Calcium oxalate (most common)
■ Struvite
■ Uric acid
■ Cystine

Acute Renal Colic

Renal stones most commonly become symptomatic when they obstruct the
ureter, causing renal colic. Complete obstruction may cause irreversible dam-
age after 1–2 weeks.

There are five sites along the ureter where calculi are likely to cause obstruc-
tion: Calyx of kidney, ureteropelvic junction, pelvic brim, ureterovesicular
junction (most common),and vesicle orifice.

TABLE 18.6. Renal Stones

STONETYPE PATHOPHYSIOLOGY

Calcium oxalate ↑Ca2+production (hyperparathyroidism, neoplasm, sarcoid, RTA).

(most common) ↑Oxalate absorption (inflammatory bowel disease).

Struvite Infection with urea-splitting bacteria (Pseudomonas,

Klebsiella, Staphylococcus, Proteus)

May cause staghorn calculi and alkaline urine

Uric acid ↑Uric acid excretion in the urine (gout, leukemia,

or high protein diet).

Low urine pH supports stone formation.

Cystine (rare) Inborn errors of metabolism

The differential of acute

renal transplant rejection?

Renal artery stenosis

Cyclosporin or tacrolimus

toxicity

Obstruction

UTI