renal / urogenital disorders in the neonates

What are the 4 ways we can evaluate the neonates kidneys in case of a possible abnormality? (4)

1. History

2. Physical examination

3. Lab evaluation

4. Special investigation

What is the embryological development of the kidneys?

From the mesoderm through 3 three sequential overlapping stages called the pronephors, mesonephros, and metanephros

What role do the kidneys play during intrauterine life?

Kidneys plan a minor role due to the placenta

What is the import part of the prenatal kidneys? (2) Function?

Urine formation and excretion - to maintain adequate amount of amniotic fluid

Do newborns have a low GFR?

Yes and it decreases with gestational age

Why does the developing kidney have a low concentrating of urine ability? (2)

1. Low GFR

2. Reduced capacity of sodium transporters

What are clinical features of acute kidney injury in a neonate? (4)

1. Serum creatinine values (decreased GFR) differ with gestational age

2. Electrolyte imbalances

3. Generalised edema

4. Oligura > urine output dripping below 0.5 ml/kg/h

What causes of acute kidney injury can occur from where? (3)

1. Prerenal

2. Renal

3. Post renal

Which criteria classifies acute kidney injury into 3 severity stages? What are those stages? What are the two outcome classes?

RILE - Risk, injury, failure

Two long term outcomes - Loss and End stage renal disease

What is the other criteria to define acute kidney injury?

KDIGO - kidney disease improving global outcomes

What value classifies hypernatremia? What are the causes? (4)

Na > 145

1. Increased salt intake

2. Increased water loss

3. Inability to maintain water balance

4. Inadequate water intake

What value classifies hyponatremia? What are the causes? (4)

Na < 132

1. Inadequate salt intake

2. Excessive salt loss

3. Immature renal function

4. Immature intestinal function

Define hydronephrosis

One / both kidneys swell with urine because it cannot drain properly down to the bladder ( a sign of obstructive uropathy)

What is a cause of post renal acute kidney injury?

Hydronephrosis

Where is the most common cause of hydronephrosis?

Ureteropelvic junction obstruction

What other side site is a common area of obstruction in Hydronephrosis?

Ureterovesical junction > where the ureter connects to the bladder

In 10-40% of cases what may happen in the case of hydronephrosis?

Vesicoureteral reflux (VUR) - where urine flows backward from the bladder up into the ureters and back towards the kidneys usually due to a detect in the valve where the ureter meets the bladder

What is the most common cause of lower urinary tract obstruction?

Posterior urethral valves

Which condition is the most common renal inherited disorder? What does it cause?

Autosomal dominant polycystic disease - progressive bilateral renal disease

Which condition presents in newborns with abdominal mass, hypertension, renal insufficiency, pulmonary hypoplasia (due to associated oligohydramnios)?

Autosomal recessive polycystic kidney disease

If to you suspect a UTI in a newborn what should you do? (2) If first method is not possible?

Urine dipstick > Urinalysis with microscopy + Urine culture via supra public aspirate or urethral catherization

If not possible then collect urine via bag specimen

How does newborn urine look? (2)

1. Clear

2. Colourless

What is the specific gravity (SG- concentration of urine) of a newborn with an UTI?

<1.004

Which 2 diagnostic findings increase the suspicion for UTI? (2)

1. Leukocyte esterase

2. Nitrate presence

What are the common organism for UTI? (3)

1. E.Coli

2. Klebsiella species

3. Enterobacter species

What is the treatment for a UTI? (2)

Broad spectrum - Ampicillin & gentamycin

What special investigation can be done to confirm the presence of an UTI?

Renal ultrasound

Define an inguinal hernia in the neonate?

Protrusion of internal organs

Define a hydrocele in the neonate?

Collection of fluid

Differentiate between inguinal hernia and hydrocele

Inguinal - unable to palpate above lesion, doesn’t transilluminate, presence of cough impulse

Hydrocele - able to palpate above lesion, transilluminates, no presence of cough impulse

Inguinal hernia is more common in which babies?

Preterm babies

Inguinal hernias are most common on which side?

Right

What is the treatment for inguinal hernia?

Surgical repair > it’s incarcerated (stuck and cannot move back)

What is the treatment for hydrocele?

Spontaneously resolves in 18- 24 months

Define hypospadias

Common birth defect where r the opening of the urethra is located on the underside of the penis rather than the tip with associated ventral penile curvature

What is the 2nd most common genital birth defect in boys?

Hypospadias

When is surgical repair done for body with hypospadia?

6- 18 months of age

Define congenital adrenal hyperplasia

A group of inherited genetic disorders (autosomal recessive) that affect the adrenal glands leading to shortage of adrenocortical & cortisol from cholesterol, and the over production of androgens (male sex hormones)

What is the most common missing/ faulty enzyme that causes congenital adrenal hyperplasia?

21-hydroxylase

Explain 46, XX DSD

Masculinization in an individual with 46, XX chromosomes develops male / ambiguous external genitalia

Define simple virilizing form of congenital adrenal hyperplasia

Moderate form where the remaining enzymes preserve normal salt balance

Define salt wasting form of congenital adrenal hyperplasia

Severe, life-threatening form involving a complete enzyme deficiency blocking both cortisol and aldosterone

When does salt losing adrenal crisis usually start?

1-3 weeks of age

What is the clinical presentation of congenital adrenal hyperplasia look like in females and males? (2 each)

1. Female > genitalia may appear ambiguous with enlarged clitoris

2. Make > enlarged penis and pigmented scrotum

What can salt-wasting congenital adrenal hyperplasia cause? (7)

1. Dehydration

2. Low blood pressure

3. Hyperkalemia

4. Very low hyponatremia

5. Weight loss & vomiting

6. May have hypoglycaemia

7. Circulatory collapse

All leading to adrenal crisis

What is the treatment of salt-wasting (3) and simple virilzing (1)?

Salt-wasting > lifelong replacement of both glucocorticoids (hydrocortisone) + mineralocorticoids (fludrocortisone) + salt supplements

simple virilizing > glucocorticoids replacement (to stop excess androgen production)