Pediatrics: Ch 24: Kidney & Urinary
Tract
What should be included in the history when renal disease is suspected? -
ANSWER Preceding acute or chronic illnesses, rashes or joint pain/swelling, growth
delay or failure to thrive, urinary symptoms, hematuria/proteinuria, pain, sudden
weight gain/loss or edema, drug/toxin exposure, perinatal history, family history of
kidney disease
What are important aspects of the physical examination for evaluating the kidney
and urinary tract? - ANSWER Height, weight, growth percentiles, skin lesions,
pallor, edema, skeletal deformities, anomalies of ears/eyes/external genitalia, blood
pressure measurement, abdominal palpation and auscultation
What should be assessed during blood pressure measurement in a child? -
ANSWER Measured in a quiet setting, with a manual cuff of appropriate size, in the
right upper extremity, child seated with feet flat on the ground, cuff covering two-
thirds of the child's upper arm, assessment of peripheral pulses
What should be assessed during abdominal palpation and auscultation in a child? -
ANSWER Nephromegaly, abdominal masses, musculature, ascites, bruits
What is the purpose of laboratory evaluation of renal function? - ANSWER To
assess kidney function and detect abnormalities
What is serum analysis? - ANSWER Measurement of various substances in the
blood to evaluate kidney function
What substances are commonly measured in serum analysis for renal function? -
ANSWER Creatinine, blood urea nitrogen (BUN), electrolytes (sodium, potassium,
chloride), albumin
What is the significance of creatinine in serum analysis? - ANSWER Indicates
kidney function and can help diagnose kidney disease
What is the significance of blood urea nitrogen (BUN) in serum analysis? -
ANSWER Indicates kidney function and can help diagnose kidney disease
What is the significance of electrolytes (sodium, potassium, chloride) in serum
analysis? - ANSWER Imbalances can indicate kidney dysfunction
What is the significance of albumin in serum analysis? - ANSWER Low levels can
indicate kidney damage or disease
,What is urinalysis? - ANSWER Examination of urine to assess kidney function and
detect abnormalities
What are the components of a urinalysis? - ANSWER Physical characteristics,
chemical analysis, microscopic examination
What physical characteristics are assessed in urinalysis? - ANSWER Color, clarity,
odor, specific gravity
What chemical analysis is performed in urinalysis? - ANSWER Measurement of
substances such as glucose, protein, blood, pH
What microscopic examination is performed in urinalysis? - ANSWER Detection of
cells, casts, crystals, bacteria
What is a urine culture? - ANSWER Laboratory test to identify and determine the
sensitivity of bacteria in the urine
What is a renal ultrasound? - ANSWER Imaging test that uses sound waves to
visualize the kidneys and urinary tract
What is a renal biopsy? - ANSWER Procedure to obtain a small sample of kidney
tissue for microscopic examination
What are the standard indicators of renal function? - ANSWER Serum levels of
urea nitrogen and creatinine.
What is the normal ratio of urea nitrogen to creatinine? - ANSWER 10:1.
When may the urea nitrogen to creatinine ratio increase? - ANSWER When renal
perfusion or urine flow is decreased.
What can cause an increase in the urea nitrogen to creatinine ratio? - ANSWER
Urinary tract obstruction or dehydration.
Why is serum creatinine considered the most reliable single indicator of glomerular
function? - ANSWER Because it is less affected by factors like nitrogen intake,
catabolism, and corticosteroid use.
What factors can affect the generation of creatinine? - ANSWER Age, sex,
malnutrition, chronic illness, and amputation.
How does serum creatinine level change over the first 1-2 weeks after birth? -
ANSWER It declines to reach a normal level for age.
What is serum cystatin C? - ANSWER A cysteine protease inhibitor produced by
all nucleated cells and released in the blood.
,How are levels of serum cystatin C affected? - ANSWER They are not affected by
sex, height, or muscle mass.
What is an additional indicator of glomerular function besides creatinine? -
ANSWER Serum cystatin C.
What are some limitations of cystatin C assays? - ANSWER They are less widely
available and less reliable in certain clinical settings.
What are some less precise but important indicators of possible renal disease? -
ANSWER Abnormalities of serum electrolytes, bicarbonate, pH, calcium,
phosphorus, magnesium, albumin, or complement.
What does GFR stand for? - ANSWER Glomerular Filtration Rate.
What does GFR measure? - ANSWER The rate at which blood is filtered by the
glomeruli in the kidneys.
What does endogenous creatinine clearance (CCr) estimate? - ANSWER
Glomerular filtration rate (GFR)
What is the 'classic' approach for determining CCr? - ANSWER A 24-hour urine
collection
Why is it difficult to accurately obtain CCr in the pediatric population? - ANSWER
Especially in children who are not continent
What is the normal range for total daily creatinine excretion? - ANSWER 15-25
mg/kg
Are normal values higher in males or females? - ANSWER Higher in males,
reflective of differences in muscle mass
What does the CCr formula require measurements of? - ANSWER Plasma or
serum creatinine (PCr), urine creatinine (UCr), and urine volume (V)
What is the formula for calculating CCr? - ANSWER CCr = (UCr x V) / PCr
Why is correction for size needed in children? - ANSWER Because accepted
ranges of normal CCr are based on adult parameters
What is the standard body surface area used for correction in the formula? -
ANSWER 1.73 m2
At what age do children reach adult levels of GFR? - ANSWER Approximately 2
years of age
What does GFR below 90 mL/min/1.73 m2 in children > 2 indicate? - ANSWER
Underlying kidney disease
, When can equations to estimate GFR be used? - ANSWER When the creatinine is
stable and not in patients with acute kidney injury (AKI)
What is the 'Bedside Schwartz' equation used for? - ANSWER Approximating
estimated GFR in children
What are the variables used in the 'Bedside Schwartz' equation? - ANSWER
Plasma or serum creatinine level and length in centimeters
What is the formula for the 'Bedside Schwartz' equation? - ANSWER eGFR =
0.413 x height (cm) / PCr (mg/dL)
What is the Creatinine-Cystatin C-based CKiD equation used for? - ANSWER
Estimating GFR when cystatin C (cysC) and blood urea nitrogen (BUN) are
assessed
What is the formula for the Creatinine-Cystatin C-based CKiD equation? -
ANSWER Not provided in the notes
Who was the 'Bedside Schwartz' equation developed for? - ANSWER Children
with chronic kidney disease (CKD)
Has the 'Bedside Schwartz' equation been validated in children with normal renal
function? - ANSWER Yes
What is the purpose of the confirmatory test for estimated GFR? - ANSWER To
provide a more accurate measurement in certain circumstances.
Where can online tools be found to calculate GFR? - ANSWER
https://www.kidney.org/professionals/KDOQI/gfr_calculatorPed
What data was used to develop new eGFR equations for children and young adults
with CKD? - ANSWER Data from the Chronic Kidney Disease in Children Study
(CKiD)
What variables are used in the new eGFR equations for children and young adults
with CKD? - ANSWER Age and sex-dependent variables
Where can an online tool for calculating eGFR in children and young adults with
CKD be found? - ANSWER https://ckid-gfrcalculator.shinyapps.io/eGFR/
What are the symptoms of inability to concentrate urine? - ANSWER Polyuria,
polydipsia, or enuresis
How can the kidney's concentrating ability be tested? - ANSWER By determining
the specific gravity of a first morning void
What is the specific gravity threshold for a concentrated first morning void? -
ANSWER ≥ 1.020