Module 9: Renal Patho In Pediatrics (c)

Question 1

Fluid and Electrolyte Balance

-Info

Answer 1

1. Blood flow to the kidney in a newborn is primarily to medullary nephrons
2. Short Loops of Henle lead to more dilute urine
3. Infants are in high anabolic state so urea excretion is low
   —Urea is required to establish concentration gradient in the medulla

Question 2

Fluid and Electrolyte Balance

-Infants

Answer 2

1. Infants have NARROW chemical safety margin
   - High hydrogen ion concentration
   - Low osmotic pressure
   - Limited ability to regulate internal environment
2. Immaturity and smaller tubule surface area diminish the water reabsorption response to vasopressin (aka ADH)

Any amount of diarrhea, infection, poor feeding can rapidly lead to acidosis and electrolyte/fluid imbalance**

Question 3

Fluid and Electrolyte Balance

-Location and Exchange of body water

Answer 3

1. Extracellular fluid volume in newborn is 2X that of an adult
2. Total electrolyte concentration in extracellular fluids is greater in newborn than adult
3. Adults take in and excrete 5% of total body fluid and 14% of ECG
4. Infants exchange 600-700 ml (290% of total or nearly 50% of the extracellular volume)**
   —Control of dehydration and over hydration MORE DIFFICULTTEST

Question 4

Congenital Abnormalities

-Types

Answer 4

1. Ectopic Kidneys — Fail to ascend from pelvis to abdomen
2. Horseshoe Kidney — Kidneys fuse at midline causing U shaped kidney
3. Hypospadias — Meatus located on the ventral side/undersurface of the penis anywhere from glans to perineum** Disruption of male hormones** TEST**
4. Chordee — Shortage of skin on ventral surface causing penis to bend or bow ventrally — can accompany hypospadias

Question 5

Congenital Abnormalities

-Exstrophy of the bladder

Answer 5

1. Herniation of the bladder through the abdominal wall.

—Bladder turns inside out — Failure in abdominal muscles

Question 6

Congenital Abnormalities

-Epispadias

Answer 6

1. Males — Urethral opening is on dorsal surface of the penis
2. Females — Cleft along the ventral urethra usually extends to the bladder neck
   —2X more boys affected as girls

Question 7

Congenital Abnormalities

-Life threatening Problems (3)

Answer 7

1. Hypoplastic Kidneys —Small w/ decrease number of nephrons
2. Renal Dysplasia — Abnormal differentiation of renal tissues
3. Renal Agenesis —Absence of one of both kidneys

Question 8

Glomerulonephritis

-Causes in Children?

Answer 8

1. Acute post-streptococcal glomerulonephritis (PSGN) — MOST common form of GN in children
   —S/P throat or skin infection with group A b-hemolytic strep
   —Antigen-antibody complexes and complement are deposited in glomerulus — initiation of inflammation and glomerular injury
   —Sudden onset of hematuria, edema, HTN, and renal insufficiency

Question 9

Henoch-Schonlein Purpura Nephritis

-Info

Answer 9

1. Anaphylactoid Purpura
2. Immune-Mediated IgA Vasculitis — Causes inflammation and damage to glomerular blood vessels
3. Clinical Manifestations
   - Palpable Purpura
   - Arthritis
   - Abdominal pain
   - Renal disease, characterized by gross or microscopic hematuria w/ mild or no proteinuria

Question 10

Hemolytic-Uremic Syndrome -HUS

-Info

Answer 10

1. MOST common community-acquired cause of acute renal failure in young children — Most occur in those <4 yrs of age
2. Association between HUS and bacterial agents — E. Coli
3. Bacterial toxin from E. Coli damages RBC’s and glomerular capillary endothelial cells
   —Damaged RBC’s are removed from the sleep leading to ACUTE HEMOLYTIC ANEMIA — Purpura or easy bruising
4. Arterioles of the glomerulus becomes swollen and occluded with fibrin clots
5. Caused by Unpasturized drinks, contaminated meats or contaminated vegetables

GOOD PROGNOSIS

Question 11

Nephrotic Syndrome in Children

-Info TEST

Answer 11

1. Group of symptoms characterized by
   - Edema
   - Proteinuria
   - Hypoproteinemia
   - Hyperlipidemia and lipiduria

Question 12

Nephrotic Syndrome in Children

-Causes

Answer 12

1. Minimal Change Nephropathy (MCN) — Fusion of podocyte foot processes
   —Underlining microscopy appear normal — No immunoglobulin deposition
2. Focal Segmental Glomerulosclerosis (FSGS)
   —More common in African American children
   —Thinning or deletion of podocyte foot processes

Question 13

Nephrotic Syndrome in Children

-Clinical Manifestations

Answer 13

1. FIRST SIGN — Periorbital edema when waking up from nap or sleep
   —During the day, edema shifts to abdomen & Lower extremities
2. Hyperlipidemia
   —Lipiduria results from loss of lipids through damaged glomerulus TEST
3. Hypercoagulation
   —Risk for arterial or venous thrombosis — Resulting from abnormalities in coagulation pathways
4. Diminished, frothy, or foamy urine output
5. Diarrhea, anorexia, and poor absorption

Question 14

Wilms Tumor (Nephroblastoma)
-Info

Answer 14

1. MOST common kidney cancer in pediatrics
2. Average age at Dx is 3-4 yrs old
3. 5 yr survival rate is 80%

Question 15

Wilms Tumor (Nephroblastoma)
-Clinical Manifestations **TEST**

Answer 15

1. Enlarging asymptomatic upper abdominal mass in a HEALTHY, THRIVING child — MOST COMMON 90%
2. Vague abdominal pain
3. Hematuria
4. Fever
5. HTN

Question 16

Cystitis

-Clinical Manifestations

Answer 16

MOST COMMON pathogen is E. Coli

1. Fever of undetermined origin
2. Frequency, urgency
3. Enuresis or incontinence in previously dry child
4. Abdominal, flank or back pain
5. Foul-Smelling urine
6. Hematuria

Question 17

Cystitis

-Clinical Manifestations in Infants

Answer 17

1. N/V/D

2. Jaundice

Question 18

Pyelonephritis

Clinical Manifestations in Pediatrics

Answer 18

1. All Cystitis Sx’s PLUS — Chills and fevers — Occasionally enlarged kidneys d/t EDEMA*

Question 19

Vesicuoureteral Reflux

-Info

Answer 19

1. Retrograde flow of urine from the bladder into 1 or both ureters
2. MOST COMMON urologic finding in children
   - White/Black ratio — 3:1
   - Girls/Boys ration —2:1
3. Caused by congenital abnormality or ectopic insertion of ureter into the bladder — Should stop at bladder wall