Chapter 42
Acute Renal Injury and Chronic Kidney Disease
1119
type of protein (
e.g.,
low molecular weight globulins or
albumin) depends on the type of kidney disease. Increased
excretion of low molecular weight globulins is a marker of
tubulointerstitial disease, and excretion of albumin a marker
of CKD, resulting from hypertension or diabetes mellitus.
18
For the diagnosis of CKD in adults and postpuberal children
with diabetes, measurement of urinary albumin is preferred.
18
In most cases, urine dipstick tests are acceptable for detect-
ing albuminuria. If the urine dipstick test is positive (1+ or
greater), albuminuria is usually confirmed by quantitative
measurement of the albumin-to-creatinine ratio in a spot
(untimed) urine specimen.
18,19
Microalbuminuria, which is an
early sign of diabetic kidney disease, refers to albumin excre-
tion that is above the normal range, but below the range nor-
mally detected by tests of total protein excretion in the urine.
19
Populations at risk for CKD (
i.e.,
those with diabetes mellitus,
hypertension, or family history of kidney disease) should be
screened for microalbuminuria, at least annually, as part of
their health examination.
18
Other markers of kidney damage include abnormalities
in urine sediment (red and white blood cells) and abnormal
findings on imaging studies.
19
Also, the biomarker amino acid,
cystatin C also known as cystatin 3, which has been used for
predicting new onset cardiovascular disease has also been
found to predict kidney disease.
20
Ultrasonography is par-
ticularly useful for detecting a number of kidney disorders,
including urinary tract obstructions, infections, stones, and
polycystic kidney disease.
Mr. Reterez
has a + urine dipstick for albumin/
protein and blood. If he had been screened a few
years ago, his microalbumin would most likely
have tested positive. It would have been very helpful if his
family members had told him more information regarding
the family’s genetic disorder, which has seemingly been
passed down through the generations. It is essential to
know whether or not one carries the polycystic kidney gene
for two reasons. First, a person can be screened carefully
for any signs of renal disease and second, a person can be
put on a list for a renal transplant early before the systemic
symptoms and multisystem disease manifests. Both of
Mr. Reterez’s kidneys are involved with polycystic kidney
disease. Therefore, he is in urgent need of dialysis or a
bilateral renal transplant.
Clinical Manifestations
The manifestations of CKD include an accumulation of nitrog-
enous wastes; alterations in water, electrolyte, and acid–base
balance; mineral and skeletal disorders; anemia and coagula-
tion disorders; hypertension and alterations in cardiovascular
function; gastrointestinal disorders; neurologic complications;
disorders of skin integrity; and disorders of immunologic
function
17,21
(Fig. 42.4). The point at which these disorders
make their appearance and the severity of the manifestations
are determined largely by the extent of renal function that is
Chronic kidney disease
Sodium and water
balance
Potassium
balance
Elimination of
nitrogenous
wastes
Erythropoietin
production
Phosphate
elimination
Hypertension
Increased
vascular
volume
Heart
failure
Edema
Pericarditis
Hyperkalemia
Uremia
Coagulopathies
Anemia
Acidosis
Bleeding
Osteodystrophies
Sexual
dysfunction
Neurologic
manifestations
Gastrointestinal
manifestations
Skin
disorders
Impaired
immune
function
Acid–base
balance
Skeletal
buffering
Hypocalcemia
Activation of
vitamin D
Hyperparathyroidism
FIGURE 42.4
•
Mechanisms and manifestations of CKD.
