First Aid for the Pediatrics Clerkship, 3 Ed.

Renal, Gynecologic, and Urinary Disease

 

ACID-BASE DISORDERS

Normal Acid-Base Balance

pH, 7.4; Pco2, 40; O2 sat, 98–100%.


Image

The notation commonly used for blood gases whether arterial or venous is: pH/Pco2/PO2/calculated HCO3/calculated SaO2—bicarbonate may also be included.


DIAGNOSIS

Diagnose acid-base disorders by obtaining an arterial blood gas (ABG—pH and Pco2) and an electrolyte panel (HCO3).

Image Assess the acid-base disorder step by step:

Image Is the primary disorder an acidosis (pH < 7.4) or alkalosis (pH > 7.4)?

Image Is the disorder respiratory (pH and Pco2 move in opposite directions)?

Image Is the disorder metabolic (pH and Pco2 move in the same direction)?

Image Is the disorder a simple or mixed disorder?

Acidosis

Image Acidosis induces ion shifts at the cellular level that cause hyperkalemia and hypercalcemia. This can manifest clinically as a cardiac arrhythmia.

Image There is a right shift of the O2-Hg dissociation curve, which means Image affinity resulting in Image oxygen release of oxygen to the tissues

Image Image cerebral blood flow, but Image pulmonary blood flow.


Image

ABG = 7.35–7.45/35–45/80–100/18–23

VBG = 7.25–7.35/41–51/35–40/18–23


METABOLIC ACIDOSIS

Image Image serum pH caused by a Image in plasma HCO3. It is important to identify the underlying cause of metabolic acidosis by calculating the anion gap (AG).

Image AG = [Na+] – ([Cl] + [HCO3]). Normal AG = 8–16 mEq/L, and reflects unmeasured serum ions (organic acids, phosphates, etc.).

Image Normal AG metabolic acidosis results when the low HCO3 levels are balanced by a compensatory Image in renal Cl reabsorption, keeping the AG in range. This is also commonly referred to as a hyperchloremic metabolic acidosis.

Image Diarrhea is the most common cause of normal AG metabolic acidosis, and is due to excessive gastrointestinal HCO3 loss. Renal tubular acidosis is another metabolic disturbance caused by ineffective reabsorption of HCO3(proximal), or excretion of H+ (distal).

Image Image AG metabolic acidosis can be due to Image serum H+ from exogenous sources (MUDPILES), or Image endogenous production (lactic acidosis/ketoacidosis/renal failure).

Image Treat metabolic acidosis by correcting the underlying disorder. Severe metabolic acidosis (pH < 7.2) results in compensatory hyperventilation (Kussmaul’s breathing), and diminished responsiveness to catecholamines that results in Image cardiac output and tissue perfusion. Treat patients with pH < 7.15 with Na+HCO3.

RESPIRATORY ACIDOSIS

Image Image serum pH due to pulmonary retention of CO2 (PaCO2 > 40 mmHg).

Image Renal compensation consists of increasing reabsorption of HCO3.

Image Acute compensation occurs at a rate of 1 mmol/L per 10 mmHg Image in PaCO2.


Image

Causes of Image anion gap metabolic acidosis:

MUDPILES

Methanol

Uremia

Diabetic ketoacidosis (DKA)

Paraldehyde

Isoniazid

Lactate

Ethylene glycol

Salicylates


Image Chronic compensation occurs at a rate of 4 mmol/L per 10 mmHg Image in PaCO2.

Image Make sure the airway is patent.

Image Correct potential reversible causes.


Image

PaCO2 is expected to Image as a result of compensatory hyperventilation in metabolic acidosis.


Alkalosis

Image Alkalosis induces ion shifts at the cellular level that cause hypokalemia and hypocalcemia.

Image There is a left shift of the O2-Hg dissociation curve, resulting in Image oxygen delivery to the tissue.

Image Image cerebral blood flow.


Image

Expected PaCO2 should be calculated with Winter’s formula and compared with measured Pco2 to see if compensation is appropriate.

Expected Pco2 = 1.5 (measured HCO3) + 8 ± 2

Failure of compensation is indicative of an additional primary acid-base disorder.


METABOLIC ALKALOSIS

Image

A 6-week-old child has a 2-week history of projectile vomiting that is not bile-stained. He is dehydrated and slightly jaundiced. Think: Pyloric stenosis.

The initial symptom of pyloric stenosis is nonbilious vomiting. Progressive vomiting results in hypochloremic hypokalemic metabolic alkalosis. Most likely lab findings: Na 138, K 3.0, Cl 88, HCO3 35, pH 7.52. Jaundice due to Image level of glucuronyl transferase may be present, which resolves after relief of the obstruction. Image awareness has resulted in earlier diagnosis.

Image Image serum pH due to an Image plasma HCO3.

Image Mechanism relies on fact that the renal system cannot excrete excess HCO3.

Image In children, metabolic alkalosis is caused by excessive loss of H+ (vomiting).

Image Urinalysis (UA) is the best initial step in evaluation to determine if the extracellular fluid (ECF) volume is contracted or expanded:

Image If urine Cl is < 10 mEq/L, ECF contraction, hypokalemia, and is saline sensitive.

Image If urine Cl is > 20 mEq/L, ECF expansion, hypertension, and is saline resistant.

Image PaCO2 is expected to Image as a result of compensatory hypoventilation in metabolic alkalosis.

Image Failure to compensate indicates an additional underlying primary respiratory alkalosis.

Image Treat the underlying cause.

Image Volume repletion in cases of ECF volume contraction will correct the alkalosis, and diuretics should be used when ECF volume is expanded.


Image

Watch for the possibility of two concurrent primary disturbances. In salicylate toxicity, both primary respiratory alkalosis and metabolic acidosis exist.


RESPIRATORY ALKALOSIS

Image Image serum pH due to Image plasma CO2.

Image Caused by hyperventilation (anxiety, asthma, pulmonary embolism, pneumonia, hypoxia).

Image Renal compensation (excretion of HCO3) occurs over a period of several hours:

Image Acute compensation Image HCO3 2 mEq/L, for every 10 mmHg Image in PaCO2.


Image

If an asthmatic has respiratory distress that is expected to have respiratory alkalosis, has a normal pH and normal Pco2, beware of impending respiratory failure.


Image Chronic compensation Image HCO3 6 mEq/L, for every 10 mmHg Image in PaCO2.

Image Treat respiratory alkalosis by treating the underlying disorder. Breathing into a paper bag can be useful in cases of psychogenic hyperventilation.

RENAL TUBULAR ACIDOSIS (RTA)

Image

A 1-year-old child is brought into the emergency department (ED) with vomiting, constipation, and Image urine production. The child is found to have normal anion gap metabolic acidosis. A renal ultrasound reveals medullary nephrocalcinosis. Think: Renal tubular acidosis.

Renal tubular acidosis is characterized by normal anion gap metabolic acidosis. A urine pH < 5.5 suggests proximal RTA, whereas in distal RTA urine pH > 6.0. Presence of nephrocalcinosis and hypercalciuria are suggestive of distal RTA.

DEFINITION

Image A renal tubular disorder resulting in normal anion gap hyperchloremic acidosis, due to impaired urinary acidification.

Image Presence of acidemia and alkaline urine, with preserved glomerular function.

Image Hyperchloremic metabolic acidosis with a high urinary pH.

Image RTA type 1 is the most common form.

ETIOLOGY

Three types: 1, 2, and 4. Type 3 RTA is exceedingly rare.

Image Type 1—distal RTA:

Image Hyperchloremic metabolic acidosis with a high urinary pH.

Image Inability to secrete H+ by the distal tubule and collecting duct (bicarbonate cannot be generated) Image metabolic acidosis with alkaline urine (> 5.5).

Image Compensatory Image in excretion of other cations causing hypokalemia and hypercalciuria.

Image Can be complicated by rickets, secondary to phosphate wasting.

Image Type 1 RTA is the only type associated with renal stones.

Image Type 2—proximal RTA:

Image Caused by Image proximal tubular reabsorption of bicarbonate.

Image The mechanisms of H+ secretion in the distal tubule are overwhelmed Image HCO3 loss in urine.

Image The bicarbonate is replaced in the circulation by Cl Image hyperchloremia.

Image Image sodium delivery to the distal tubule Image aldosterone secretion Image hypokalemia.

Image Isolated disorder.

Image Generalized defect in proximal tubular transport (Fanconi syndrome). Nephrocalcinosis and nephrolithiasis do not occur despite Image urinary calcium (urinary citrate levels are not reduced).

Image Plasma HCO3 remains at 15–20 mEq/L.

Image Type 4—mineralocorticoid deficiency RTA.

Image Aldosterone deficiency or resistance.

Image Image aldosterone production by the adrenal gland (Addison disease, congenital adrenal hyperplasia, primary hypoaldosteronism).

Image Image production of renin by the juxtaglomerular apparatus (interstitial damage).

Image Nephrocalcinosis and nephrolithiasis are rarely seen.

Image Characteristic features: Hyperkalemia, acidic urine—urinary pH < 5.5 (distal tubule H+ pump functions normally).

SIGNS AND SYMPTOMS

Image Polyuria, dehydration, anorexia, vomiting, constipation, and hypotonia.

Image Children often present with growth failure.

TREATMENT

Image Correct acidosis:

Image Sodium bicarbonate (alkalinize the urine, correct the sodium defect, lower aldosterone, and raise the potassium).

Image Potassium citrate (augments urinary citrate and inhibits stone formation).

Image Caution! NaHCO3 in Type II can correct the condition but can Image further hypokalemia, and potassium supplements may also be required.

Image Correct electrolyte abnormalities to maintain bicarbonate and potassium levels: Potassium citrate therapy is able to correct the metabolic acidosis and hypokalemia in distal renal tubular acidosis.


Image

The primary defect in distal renal tubular acidosis is a defect in secretion of hydrogen ions.


PROGNOSIS

Image Distal RTA can be a lifelong disease and may Image renal failure.

Image Proximal RTA and mineralocorticoid RTA usually resolve within 12 months.

ACUTE RENAL FAILURE (ARF)

Image

A 4-year-old boy develops oliguria 12 hours after operation for a ruptured appendix. Creatinine (Cr) is 0.5 mg/dL, blood urea nitrogen (BUN) is 23 mg/dL, urine sodium is 12 mEq/L. Think: Prerenal azotemia.

Oliguria is most often due to dehydration. Historical features are vomiting, diarrhea, and poor oral intake. A BUN-to-serum creatinine ratio of > 20:1 is suggestive of prerenal azotemia. Other features are Image concentration of urinary sodium, Image urinary excretion of creatinine, and a high urine osmolality. The precipitating event for prerenal azotemia is renal hypoperfusion. Give physiologic saline for blood volume expansion. Reversibility with treatment of the underlying cause is the hallmark.

Image

A 2-year-old boy develops bloody diarrhea a few days after eating in a fast-food restaurant. A few days later, he develops facial edema, pallor, lethargy, and Image urine output. Blood work shows a low hematocrit and platelet count. A UA reveals blood and protein in the urine. Think: HUS secondary to Escherichia coli O157:H7 infection.

This infection is commonly acquired by eating undercooked red meat (hamburgers). It is usually preceded by either gastroenteritis (usually diarrheal) or an upper respiratory tract infection. Sudden onset of pallor, lethargy, and oliguria suggest HUS. Microangiopathic hemolytic anemia and thrombocytopenia support the diagnosis of HUS. The peripheral smear may show helmet cells, burr cells, and fragmented red cells.

Image

A 5-year-old patient with ARF has an electrocardiogram (ECG) that shows peaked T waves and a widened QRS complex. Think: Hyperkalemia.

Hyperkalemia occurs due to impaired renal excretion. As K+ levels rise, peaked T waves are the first ECG changes. Further rise results in widening of the QRS complex. All patients with suspected hyperkalemia should be placed on a cardiac monitor. The initial treatment includes administration of calcium chloride or gluconate to treat hemodynamic instability, and initiation of measures to lower serum K+.

DEFINITION

Image ARF develops when renal function is diminished to the point where body fluid homeostasis can no longer be maintained.

Image Acute rise in BUN, serum creatinine, or both.

Image Three main types: prerenal, renal, and postrenal.

Image ARF results in azotemia (elevated BUN).

Image May present with symptoms of oliguria, anuria, or insidiously without oliguria.

PATHOPHYSIOLOGY

Image Prerenal:

Image Caused by hypoperfusion of the kidneys secondary to hemorrhage, sepsis, heart failure, or salt/protein-wasting disease.

Image This is the most common cause of ARF.

Image Potentially reversible if blood flow is restored prior to progression to acute tubular necrosis (ATN).

Image Oliguria is always present.

Image Gastroenteritis is the most common cause of hypovolemia.

Image Renal:

Image Caused by renal parenchyma damage, usually from tubular disease (most commonly ATN), glomerular disease (Wegener, Goodpasture, systemic lupus erythematosus [SLE]), vascular disease (HUS or renal vein thrombosis), and interstitial disease (medications).


Image

The most common cause of ARF in toddlers is hemolytic-uremic syndrome (HUS).


Image The kidneys are unable to concentrate urine effectively.

Image Usually presents with edema.

Image Consider poststreptococcal glomerulonephritis in a child presenting with hypertension, edema, hematuria, and renal failure.

Image Postrenal:

Image Caused by any significant obstruction of the urinary tract (posterior urethral valves, bilateral uretropelvic or uretrovesical obstruction).

Image Almost always associated with infection.


Image

Nephritic syndrome: Hematuria, edema, and hypertension.


SIGNS AND SYMPTOMS

Image Oliguria.

Image Edema (salt and water overload).

Image Hypertension (HTN).

Image Congestive heart failure (CHF).

Image Seizures.


Image

Normal urinary output: 2–4 ml/kg/hr


DIAGNOSIS

Image Find out the duration, and attempt to get a baseline Cr level.

Image Obtain a careful history to determine the cause of renal failure.

Image Serum and urine chemistry are useful tests for differentiating the cause.

Image Prerenal: BUN:Cr > 20:1 with FeNa < 1%.

Image Renal: BUN:Cr < 20:1 and FeNa > 2–3%.

Image In children with postrenal ARF, a renal ultrasound will show dilation of the renal pelvis and collecting system.


Image

Oliguria: < 0.5 mL/kg/hr urine production


TREATMENT

Image Catheterize the patient to monitor urine output and relieve obstruction.

Image Treat patients with hypovolemia with volume replacement.

Image Treat patients who fail to produce adequate urine output with fluid restriction.

Image Avoid drugs that can precipitate prerenal failure (such as nonsteroidal anti-inflammatories [NSAIDs]) in patients with Imagerenal perfusion.


Image

Children with renal failure may have a normal urinary output.


COMPLICATIONS OF UNTREATED ARF

Image Hyperkalemia can develop secondary to impaired renal tubule function and ion shifts due to acidosis. A serum potassium level > 7 mEq/L must be treated emergently. Give calcium gluconate to stabilize the myocardium, bicarbonate, glucose and insulin, Kayexalate (sodium polystyrene), and albuterol. Cardiac arrest from hyperkalemia is a life-threatening complication of untreated ARF.

Image Hypocalcemia and hyperphospatemia may result from parathyroid hormone (PTH) resistance and loss of ability to hydroxylate vitamin D into an active form. Severe hypocalcemia manifests as tetany, and is treated by lowering phosphate and replacing active vitamin D.

Image Anemia is often caused by lowered erythropoietin levels. Erythropoietin can be supplemented.

Image Hyponatremia secondary to excessive administration of hypotonic fluids to oliguric patients. Patients with a serum sodium < 120 are at risk for developing cerebral edema and central nervous system (CNS) hemorrhage. Partial correction should be undertaken to raise the Na level to at least 120 mEq Na.


Image

Patients with ARF could be either volume overloaded or volume depleted. Always assess a patient’s hydration status.


Required = (Desired Na concentration – Observed Na concentration) × Body weight (Kg) × 0.6

Treat patients with water restriction.

Image Metabolic acidosis is due to Image excretion of hydrogen and ammonia.

Image Infection is a common and serious complication.

CHRONIC RENAL FAILURE (CRF)

Image

On a routine exam, a 10-year-old girl has HTN that is confirmed by repeated measurements. Her blood pressure (BP) is 160/90 in the right arm and similar in the left arm and right leg. Think: Renal disease.

BP should be measured at least twice with appropriate cuff size. A short or narrow cuff may artificially Image BP measurement. Renal parenchymal disease and coarctation of the aorta are common causes of hypertension in children 1–10 years of age. BP should be obtained in all four extremities to determine the presence of coarctation of the aorta. The most appropriate next diagnostic test is UA.

DEFINITION

CRF is a result of irreversible kidney damage Image end-stage renal failure.

ETIOLOGY

Image CRF in children under age 5 is most often due to anatomic abnormalities, such as renal hypoplasia, dysplasia, or malformations.

Image After age 5, CRF usually results from glomerular diseases such as HUS or glomerulonephritis, hereditary diseases such as Alport syndrome, or cystic diseases.

SIGNS AND SYMPTOMS

Image The development of uremic symptoms in chronic renal disease is usually insidious and nonspecific.

Image Patients may present with headache, fatigue, lethargy, anorexia, vomiting, polydipsia, polyuria, and growth failure.

Image Most patients with CRF are weak and have HTN, as the renin-angiotensin-aldosterone system is stimulated by diminished GFR regardless of actual volume status.

Image See Table 14-1 for a listing of symptoms of uremia.


Image

Patients will often present with bleeding due to defective platelets secondary to uremia.

Uncontrolled bleeding can be treated with dialysis and desmopressin.


DIAGNOSIS

Image Serum Cr measurement will give a good estimate of glomerular filtration rate (GFR) as the two vary with an inverse relation.

Image GFR < 20% of normal is typical for CRF.

Image


Image

Always attempt to obtain a baseline Cr level to differentiate between ARF, CRF, and acute-on-chronic renal insufficiency/failure.


TREATMENT

Image Dialysis and renal transplant are indicated for patients when serum Cr is > 10 mL/dL.

TABLE 14-1. Symptoms of Uremia

Azotemia (accumulation of nitrogen products)

Acidosis

Sodium wasting

Sodium retention

Urinary concentrating defect

Hyperkalemia

Renal osteodystrophy

Growth retardation

Anemia

Bleeding tendency

Infection

Neurologic (fatigue, poor concentration, headache, drowsiness, muscle weakness, seizures, coma)

Gastrointestinal ulceration

Hypertension

Hypertriglyceridemia

Pericarditis and cardiomyopathy

Glucose intolerance

Image Diet: Children with CRF are growth retarded. Children should be given adequate caloric intake. Nasogastric (NG) tube feeds and recombinant human growth hormone therapy has been shown to improve linear growth. Water-soluble vitamins, zinc, and iron should be supplemented.

Image Renal osteodystrophy: Children with CRF are unable to excrete phosphate. The resulting hyperphosphatemia and hypocalcemia stimulate PTH. The ensuing secondary hyperparathyroidism Image fibrosis of the bone marrow space (osteitis fibrosis cystica). Symptoms of renal osteodystrophy include muscle weakness, bone pain, and growth retardation. Treatment includes normalization of the serum calcium and phosphorus levels.

Image Anemia: Anemia results from inadequate erythropoietin production by the kidneys. Children with Hgb < 6 should be transfused with packed red blood cells (RBCs). Erythropoietin can also be administered subcutaneously.

Image Hypertensive emergencies: HTN should be treated with salt restriction and a combination of angiotensin-converting enzyme (ACE) inhibitors and β blockers.


Image

Absolute indications for emergent dialysis:

AEIOU

Acidosis

Electrolyte abnormalities

Toxic Ingestion

Fluid Overload

Uremia


END - STAGE RENAL DISEASE (ESRD)

Image

An 8-year-old patient receiving peritoneal dialysis for ESRD develops abdominal pain and fever. Think: Peritonitis.

The most serious complication of peritoneal dialysis is peritonitis. It should be suspected in the presence of abdominal pain and fever in a patient who is on peritoneal dialysis. Clinical manifestations include fever and abdominal pain and tenderness. Common causative organisms are coagulase-negative staphylococci, S aureus, streptococci, Escherichia coliPseudomonas, and other gram-negative organisms.

DEFINITION

ESRD occurs when a patient’s renal function has been irreversibly compromised and failed (the serum Cr is typically > 10 mg/dL).

CAUSES

Congenital anatomic abnormalities are the most common cause in children < 5 years old, and glomerulonephritis is the most common culprit in children > 5 years old.


Image

High BUN/Cr levels are not an absolute indication for dialysis.


TREATMENT

Image Dialysis: Peritoneal dialysis is the standard technique for infants and children. However, dialysis patients remain uremic, which restricts normal growth and development.

Image Renal transplant: Renal transplantation is the preferred mode of treatment of most children with ESRD. Preparation for transplantation from living donors or listing for cadaver donor transplant should begin for all children with ESRD. The contraindications for transplant include children with human immunodeficiency virus (HIV) and children with metastatic malignancy.


Image

The most common causes of HTN in children are secondary causes—renal (75%), infection, glomerulonephritis, HUS, obstructive uropathy.


WILMS’ TUMOR

Image

A previously healthy 2-year-old boy has a left-sided flank mass discovered by his mother. His physical examination reveals a BP of 110/70 and a large mass arising in his left flank. A UA shows 5–10 erythrocytes and 2–3 leukocytes. Think: Wilms’ tumor.

The usual presentation of Wilms’ tumor is an abdominal mass, and it is not uncommon for the parent to discover this mass. Other features may include abdominal pain, fever, anemia, hematuria, and HTN. The most appropriate next diagnostic test is an ultrasound of the abdomen and urinary tract. Because Wilms’ tumor metastasizes to the lungs, a chest radiograph should be obtained.

DEFINITION

Image Nephroblastoma.

Image Embryonal neural crest cell origin.

Image It most commonly presents between the ages of 1 and 4 years (median age at diagnosis: 3.5 years).

Image The most common type of renal tumor in children.

ETIOLOGY

Wilms’ tumors are associated with mutations of the p53 tumor suppressor gene on chromosome 11.

SIGNS AND SYMPTOMS

Image Abdominal/flank mass (typically asymptomatic):

Image The most common presentation.

Image Rarely crosses the midline, as opposed to neuroblastoma.

Image Vomiting.

Image May present with gross hematuria, fever, and HTN due to obstruction of renal artery.

Image Associated with aniridia, genitourinary malformation (cryptorchidism), mental retardation, hemihypertrophy, and Beckwith-Wiedemann syndrome (macroglossia, omphalocele, visceromegaly).

Image Can be bilateral (5–10%).

PATHOLOGY

Image Stage 1: Tumor limited to kidneys and can be removed with an intact capsule.

Image Stage 2: Grows beyond the kidney but can be completely removed.

Image Stage 3: Nonhematogenous extension into the abdomen.

Image Stage 4: Hematogenous metastases.

Image Stage 5: Bilateral renal metastasis.

SPREAD

Image Contiguous invasion of adjacent organs.

Image Extension into the renal vein and inferior vena cava.

Image Distant spread: Lung and liver.

DIAGNOSIS

Image Renal ultrasound (US): Echogenic intrarenal masses that may contain cystic areas.

Image Computed tomography (CT): To determine the origin and extent of spread.

Image Biopsy: To determine cell type.

TREATMENT

Image Stage 1–3 tumors are treated with nephrectomy and chemotherapy with or without radiation.

Image Stage 4 tumors are treated with pulmonary irradiation and three-drug combination chemotherapy in addition to above.

POLYCYSTIC KIDNEY DISEASE (PKD)

Image

An 8-month-old girl has an easily palpable kidney. US shows cystic kidneys, hepatic fibrosis, and portal HTN. Think: Autosomal-recessive polycystic kidney disease.

Classic presentation: Bilateral flank masses during the neonatal period or early infancy. Ultrasound may show uniformly hyperechogenic kidneys. Presence of hepatic fibrosis supports this diagnosis. Associations: oligohydramnios, pulmonary hypoplasia, respiratory distress, and spontaneous pneumothorax.

DEFINITION

Image Bilateral renal cysts without dysplasia.

Image Congenital malformation of the urinary tract resulting in cysts within the kidneys.

PATHOPHYSIOLOGY

Image Autosomal-recessive PKD (ARPKD; previously known “infantile polycystic disease”): Cysts are a dilation of the collecting ducts. Many patients also have cysts in the liver, cirrhosis, and portal HTN.

Image Autosomal-dominant PKD (ADPKD; previously known “adult polycystic disease”): Cortical and medullary cysts that are primarily dilated tubules. Although most patients are identified between 30 and 50 years of age, the condition has been recognized in newborn.

Image Currently, the nomenclature of infantile versus adult is no longer used.

SIGNS AND SYMPTOMS

ARPKD

Image Imageurine formation by the fetus Image oligohydramnios, Potter syndrome (flat nose, recessed chin, epicanthal folds, low-set abnormal ears, limb abnormalities), and pulmonary hypoplasia.

Image At birth, infants may present with renal insufficiency or HTN. Children will also present with bilateral flank masses at birth.

ADPKD

Image Commonly presents in the fourth or fifth decade of life with hematuria, bilateral flank pain or masses, and HTN.

Image Also associated with hepatic cysts and aneurysms of the cerebral circulation.


Image

ARPKD—innumerable tiny cysts

ADPKD—large cysts


DIAGNOSIS

US of the kidneys reveals enlarged and hyperechogenic kidneys.

TREATMENT

Treatment is supportive. PKD results in ESRD. Treat patients with ESRD with dialysis and kidney transplant.

RENAL DYSPLASIA

DEFINITION

Abnormal metanephric differentiation resulting in nonrenal components affecting all or part of the kidney. A dysplastic kidney can contain nonrenal elements such as cartilage.

RENAL HYPOPLASIA

Image

A 1-week-old male newborn has a wrinkled abdomen that lacks anterior abdominal musculature. He also has clubfeet and is in respiratory distress. His bladder is distended and easily palpable, and neither testis is in his scrotum. Lab findings include BUN 30, Cr 2, and HCO3 15. Think: Prune belly syndrome.

Triad: Absent abdominal wall muscles, undescended testes, and renal dysplasia. The renal collecting system is dilated. The bladder usually enlarged with a pseudodiverticulum at the urachus. Respiratory distress may be related to pulmonary hypoplasia due to severe oligohydramnios.

DEFINITION

Image Nondysplastic small kidney that has decreased calyces and nephrons.

Image Children with bilateral hypoplasia usually present with chronic renal failure.

Image This is the leading cause of ESRD during the first decade of life.

FANCONI SYNDROME

DEFINITION

Rare disorder characterized by wasting of variable amounts of phosphate, glucose, amino acid, and bicarbonate by the proximal renal tubule.

ETIOLOGY

Image Inherited.

Image Cystinosis (defect of cystine metabolism that results in deposition of cystine in major organs of body, especially kidney, liver, eye, and brain).

Image Galactosemia.

Image Fructosemia.

Image Lowe syndrome (X-linked disorder with congenital cataracts, mental retardation, and Fanconi syndrome).

Image Tyrosinemia.

Image Wilson disease.

Image Acquired secondary to exposure to:

Image Chemotherapeutic/immunosuppressive agents (ifosfamide, tacrolimus, cyclosporine).

Image Heavy metals.

Image Gentamicin or outdated tetracycline.


Image

Cystinosis is the most common cause of Fanconi syndrome.



Image

Fanconi syndrome is one of the causes of proximal RTA.


SIGNS AND SYMPTOMS

Image Growth retardation

Image Rickets

Image Polyuria

Image Dehydration

Image Anorexia

Image Vomiting


Image

It is important to distinguish Fanconi syndrome from Fanconi’s anemia. Fanconi’s anemia is an inherited disorder of bone marrow failure, whereas Fanconi syndrome is a disorder of renal tubules.


DIAGNOSIS

Image Elevated levels of glucose and electrolytes (phosphate, sodium, potassium, bicarbonate) in the urine.

Image Evidence of renal insufficiency.

TREATMENT

Image Bicarbonate therapy is mainstay.

Image Replacement of phosphate.

HORSESHOE KIDNEY

DEFINITION

Midline fusion of the lower kidney poles.


Image

The major pathologic finding in congenital nephrotic syndrome is dilation of the proximal tubules.


EPIDEMIOLOGY

Image Seven percent of horseshoe kidneys are associated with Turner syndrome and are four times more common in children with Wilms’ tumor.

Image Horseshoe kidneys occur in 1 in 500 births.

NEPHROTIC SYNDROME

Image

A 2-year-old boy has a 1-week history of edema. On examination, his BP is 100/60 and he has generalized edema and ascites. Lab values show Cr 0.4, albumin 1.4 g/dL, and cholesterol 569 mg/dL. A UA shows 4+ protein and no blood. Think: Nephrotic syndrome.

The common age of presentation is 2–6 years. Minimal change disease is the most common pattern of nephrotic syndrome in children. Typical presentation: periorbital and peripheral edema. Additional findings may include HTN and microscopic hematuria. Histopathologic examination shows no glomerular abnormalities on light microscopy in minimal change disease.


Image

Nephrotic range proteinuria = Protein excretion of > 40 mg/m2/hr.

Random urine protein/creatinine ratio > 3.0.


DEFINITION

Nephrotic syndrome is characterized by proteinuria, hypoalbuminemia, edema, and hyperlipidemia.


Image

Patients can develop a hypercoagulable state due to nephrotic loss of antithrombin III.


ETIOLOGY

Image Eighty-five percent of nephrotic syndrome in children is caused by minimal change disease.

Image Other causes of nephrotic syndrome include mesangial proliferation and focal segmental glomerulosclerosis.


Image

Renal Biopsy

Image Age < 1 year or > 8 years

Image Recurrent gross hematuria

Image Family history of kidney disease

Image Laboratory findings suggestive of secondary nephrotic syndrome:

Image Sustained elevation in serum creatinine levels

Image Low C3/C4 levels

Image Positive antinuclear antibody (ANA) findings

Image Positive anti-double-stranded DNA antibody


PATHOPHYSIOLOGY

A loss of negatively charged glycoproteins in the capillary walls causes an Imagein basement membrane permeability.

EPIDEMIOLOGY

Image More common in boys than girls (2:1).

Image Most common in children between 2 and 6 years of age, and commonly follows a viral illness.

SIGNS AND SYMPTOMS

Image Pitting edema (most common clinical finding).

Image Periorbital edema.

Image Oliguria.

Image Anasarca.

DIAGNOSIS

Image The diagnosis is usually made clinically, with supportive laboratory values.

Image Proteinuria > 3.5 g/24 hr.

Image Serum albumin < 2.5 g/dL.

Image Hyperlipidemia.

Image A confirmatory renal biopsy shows fusion of the epithelial foot process by electron microscopy.

TREATMENT

Image Most children will respond to steroids (4–6 weeks of prednisone).

Image Relapses can be treated with steroids or alternative agents like cyclophosphamide or cyclosporine if steroid resistant.

Image Salt/fluid restriction to Image edema.

Image The majority of children will have Image relapses with age, most resolving by the end of the second decade.


Image

Urine dipstick is not an accurate measure of protein excretion.


COMPLICATIONS

Image Infection is most common, especially spontaneous bacterial peritonitis. Two organisms: Streptococcus pneumoniae and Escherichia coli.

Image Thromboembolism:

Image Higher in secondary nephrotic syndrome and membranous nephrotic syndrome.

Image Renal vein thrombosis, deep vein thrombosis, and pulmonary embolism.

POSTSTREPTOCOCCAL GLOMERULONEPHRITIS (PSGN)

Image

A 4-year-old girl presents with malaise, periorbital edema, and smoky-colored urine. She had a strep throat infection 2 weeks prior. A serum complement level is Image, and an antistreptolysin O (ASO) titer is ImageThink: PSGN.

PSGN occurs after an infection of the throat or skin by group A β-hemolytic streptococci. It is manifested as an acute nephritic syndrome or as isolated hematuria and proteinuria. It is mediated by immune complexes, which is suggested by low complement level. The ASO is elevated. Urinalysis shows red blood cells and RBC casts.


Image

Proteinuria

Normal protein excretion = ≤ 4mg/m2/hr

Normal urine protein/creatinine ratio = < 0.5 (< 2 year) < 0.2 (> 2 year)

Transient

Image Fever

Image Dehydration

Image Exercise

Orthostatic proteinuria (most common cause):

Image Obtain two samples of urine (one in recumbent and the other in ambulatory position).

Image Practically first morning urine and another sample later in the day.

Image 24-hour urinary protein excretion < 1000 mg/day.

Image Persistent (> 1+ on > 1 occasion).

Image Requires further evaluation.


DEFINITION

Image Immune complex disease caused by group A β-hemolytic streptococcus types 12 and 49.

Image Typically occurs 10–14 days following strep pharyngitis or a skin infection (impetigo).

DIAGNOSIS

Image Positive throat cultures or Imageantibody titers to streptococcal antigen.

Image UA: RBC casts, RBCs, protein.

Image Light microscopy: Enlarged glomeruli with mesangial proliferation and exudation of neutrophils.

Image Immunofluorescent microscopy: Granular pattern of immunoglobulin deposition.

Image Electron microscopy: Electron microscopy reveals electron-dense humps (immune complexes) on the epithelial side of the glomerular basement membrane (GBM).

TREATMENT

Image Treat with penicillin for 10 days to prevent spread of nephrogenic strain of group A β-hemolytic streptococci.

Image Treat renal and cardiac failure with peritoneal dialysis.

Image Microscopic hematuria may take up to 1 year to resolve.

RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS (RPGN)

DEFINITION

Image Acute glomerulonephritis = hematuria, proteinuria, and HTN.

Image Severe glomerulonephritis that rapidly progresses to acute renal failure if left untreated.

Image The underlying abnormality is the presence of crescent-shaped scars in the majority of the glomeruli.

SIGNS AND SYMPTOMS

Image RPGN presents like nephritic syndrome with nephrotic range proteinuria and rapidly progresses to ARF within weeks to months after onset.

Image Gross hematuria and/or edema is the most common presentation.


Image

Causes of gross hematuria:

OUCH RED URINE HURTS

Image Oncologic agents

Image Urethrorrhagia (secondary to squamous metaplasia of urethra)

Image Coagulopathy

Image Hydronephrosis

Image Renal vein thrombosis

Image Exercise

Image Dead papillae (papillary necrosis)

Image Urolithiasis

Image Renal contusion

Image Infections

Image Neoplasm

Image External manipulation (masturbation)

Image Hypercalciuria

Image Urethral injury

Image Renal custs

Image Trauma

Image Sickle cell


DIAGNOSIS

Image Complement C3 and C5 are usually decreased. The complement levels generally return to normal after 6–8 weeks.

Image Light, immunofluorescent, and electron microscopy reveal presence of crescents on the inside of Bowman’s capsule. The crescents are composed of the proliferative epithelial cells of the capsule, fibrin, and macrophages.

TREATMENT

Although some patients respond to corticosteroids or cyclophosphamide, prognosis is generally very poor, with most patients requiring dialysis.

MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS

Image

A patient presents with hemoptysis, sinusitis, and glomerulonephritis. Think: Wegener’s granulomatosis.

Wegener’s granulomatosis involves the upper and lower airways and kidneys. Triad: Necrotizing granulomatous lesions in the respiratory tracts, necrotizing vasculitis, and focal glomerulonephritis. It is rare before adolescence. Most patients present with respiratory symptoms. The radiographic findings may include nodular infiltrates, pulmonary nodule, cavitation, and diffuse alveolar hemorrhage.

DEFINITION

Most common cause of chronic glomerulonephritis in older children.

SIGNS AND SYMPTOMS

Image Nephrotic syndrome

Image Hematuria

Image HTN

DIAGNOSIS

Image Light microscopy: Glomeruli arranged in a lobular pattern, often appearing duplicated with a “tram tracking” appearance.

Image Immunofluorescent microscopy: Lobular deposits of C3 and immunoglobulins.

Image Electron microscopy: Immune complex deposits in mesangial and subendothelial regions.

TREATMENT AND PROGNOSIS

Image Poor prognosis. Fifty percent of patients will develop chronic renal failure within 10 years.

Image There is no definitive therapy, although some patients respond to prednisone.

MEMBRANOUS GLOMERULONEPHRITIS

Image

A patient presents with dyspnea, hemoptysis, and ARF. Think: Goodpasture syndrome.

Goodpasture syndrome is an antiglomerular basement membrane disease. Triad: glomerulonephritis, pulmonary hemorrhage, and antibody to basement membrane antigens. Respiratory manifestations: cough, dyspnea, and hemoptysis associated with pulmonary hemorrhage. Renal manifestations: acute nephritic syndrome with hematuria, proteinuria, and HTN. UA may show active sediment with RBCs and RBC casts.

DEFINITION

Membranous glomerulonephritis is an immune complex disease of the kidney.

EPIDEMIOLOGY

Image It is the most common cause of nephrotic syndrome in adults and is uncommon in children.

Image Can be idiopathic or secondary (SLE 10–20% of lupus nephritis).


Image

The most common cause of gross hematuria in children is IgA nephropathy.


SIGNS AND SYMPTOMS

Image Presents as a nephrotic syndrome.

Image Some patients have microscopic hematuria.

DIAGNOSIS

Image Light microscopy: Diffuse thickening of the GBM without proliferative changes.

Image Immunofluorescent microscopy: Granular deposits of immunoglobulin G (IgG) and C3.

Image Electron microscopy: Deposits of IgG and C3 located on the epithelial side of the membrane.

TREATMENT

Image Most cases resolve spontaneously in children, although some children will have persistent proteinuria.

Image Nephrotic syndrome is best controlled with salt restriction and diuretics.


Image

Electron microscopy of membranous glomerulonephritis shows a “spike-and-dome” pattern on the epithelial side of the GBM.


FEVER/EXERCISE/POSTURAL PROTEINURIA

DEFINITION

Image Proteinuria up to 150 mg/day may be normal.

Image Proteinuria consists of plasma, albumin, and Tamm-Horsfall proteins.

Image Postural proteinuria: Proteinuria is Image from lying in supine to upright position due to unknown cause.

Image Febrile proteinuria: Proteinuria caused by fever > 101°F (41.1°C). Febrile proteinuria will normalize after fever resolves.

Image Exercise proteinuria: Proteinuria following vigorous exercise. Usually resolves after 48 hours of rest.

Image Persistent proteinuria = glomerular lesion.

Image The most common cause of proteinuria in children is orthostatic proteinuria.


Image

Degrees of Proteinuria

1+: 30 mg/dL

2+: 100 mg/dL

3+: 300 mg/dL

4+: > 2,000 mg/dL


INTERSTITIAL NEPHRITIS–ACUTE AND CHRONIC

DEFINITION

Inflammation in the interstitium between the glomeruli in the areas surrounding the tubules.

RISK FACTORS

Image Acute: Allergy to medications (penicillin, cephalosporins, sulfonamides, rifampin, phenytoin, thiazides, furosemide, allopurinol, amphotericin B, NSAIDs) is the most common cause. Infections (especially in children), sarcoidosis, glomerulonephritis, and transplant rejection are also risk factors.

Image Chronic: Drugs (analgesics, lithium), infections, vesicoureteral reflux, urinary tract obstruction.

PATHOPHYSIOLOGY

Interstitial nephritis is often associated with tubular damage, edema, and necrosis between tubules.

SIGNS AND SYMPTOMS

Image Acute: Most patients present with ARF of generalized tubular dysfunction. Recent infections, new medications, fever, malaise, and signs of ARF should be investigated.

Image Chronic: Children usually present with symptoms of CRF such as nausea and vomiting, headache, fatigue, HTN, and growth failure.

DIAGNOSIS

Image Acute: Eosinophils in the urine suggest the diagnosis. A renal biopsy demonstrates an interstitial infiltrate of lymphocytes, plasma cells, eosinophils, and neutrophils and may help to differentiate acute interstitial nephritis (AIN) and ATN. Edema is present, and the glomeruli are typically normal.

Image Chronic: In chronic interstitial nephritis, the inflammatory cells consist of lymphocytes and plasma cells. Tubular fibrosis is present and the glomeruli are sclerosed secondary to ischemia. Renal papillary necrosis may be present.

TREATMENT

Image Treat renal failure.

Image Children with AIN may recover completely after withdrawal of the inciting agents. Children with chronic interstitial nephritis progress to ESRD.

SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)

DEFINITION

Image A systemic autoimmune disease characterized by fever, weight loss, rash, hematologic abnormalities, and arthritis.

Image Lupus nephritis is the most common manifestation of SLE in childhood.

PATHOPHYSIOLOGY

Image Immune complexes deposit into the glomeruli, causing characteristic kidney diseases.

Image See Table 14-2 for classification.

EPIDEMIOLOGY

Image Most common in adolescent females.

Image Uncommon in children < 8 years old.

SIGNS AND SYMPTOMS

Image See Table 14-2.

Image Renal disease is more frequent in children.

DIAGNOSIS

Image Elevated serum levels of anti-Smith antibodies and anti-double-stranded DNA antibodies (anti-dsDNA antibodies) are highly specific for SLE.

Image Markers of disease activity:

Image Anti-double-stranded DNA.

Image Complement levels C3 and C4.

TABLE 14-2. SLE Nephritis—World Health Organization (WHO) Classification and Symptoms

Image

TREATMENT

Immunosuppressive therapy (eg, prednisone, azathioprine) is used to help reduce/prevent flare-ups but cannot cure the disease.

RENAL VEIN THROMBOSIS (RVT) IN INFANCY

DEFINITION

Image Thrombus formation in the renal vein.

Image In infants, RVT is associated with dehydration, shock, and sepsis.

Image Occurs in infants born to mothers with diabetes mellitus.

Image In older children, RVT is associated with nephrotic syndrome (membranous nephropathy), cyanotic heart disease, hypercoagulable states, and contrast agents.

SIGNS AND SYMPTOMS

Image Acute gross hematuria

Image Oliguria

Image Flank masses

Image Flank pain

DIAGNOSIS

Image US shows enlarged kidneys.

Image Doppler flow studies show impaired (little) renal function.

Image UA shows proteinuria and/or hematuria.

TREATMENT

Image Correction of fluid and electrolyte abnormalities.

Image Prophylactic anticoagulation with heparin.

COMPLICATIONS

Image ARF (especially if bilateral).

Image Systemic HTN.


Image

Sudden onset of gross hematuria and unilateral or bilateral flank masses. Think: Renal vein thrombosisMust evaluate for hypercoagulable states.


NEUROGENIC BLADDER

DEFINITION

Abnormal innervation to the bladder and sphincter muscles, associated with spinal abnormalities such as CNS tumors, spina bifida, teratomas, and myelodysplasia.

SIGNS AND SYMPTOMS

Image Urinary incontinence.

Image Urinary retention.

Image Urinary tract infections (UTIs).

Image Renal dysfunction caused by urinary reflux from bladder to kidneys (upper tract deteriorations).

TREATMENT

Image Intermittent catheterization.

Image Anticholinergic medication (oxybutinin).

Image Surgical correction.

UROLITHIASIS

Image

An 8-year-old boy presents with left flank pain radiating to his left testicle. The pain does not change with movement or positioning and is colicky in nature. Urine dip is positive for blood. Think: Urolithiasis.

The pain begins in the flank, extends around the abdomen, and may radiate into the groin. Ipsilateral costovertebral tenderness may be present. Children with a history of multiple UTIs may be at risk of renal stones. UA typically shows hematuria, but absence of hematuria does not exclude the diagnosis of urolithiasis. Metabolic evaluation should include measurement of uric acid, electrolytes, creati-nine, calcium, phosphorus, and bicarbonate. Serum PTH level should be obtained in the presence of hypercalciuria, hypercalcemia, or hypophosphatemia.

DEFINITION

Accumulation of urinary calculi in the urinary tract.

EPIDEMIOLOGY

Image More common in boys than girls (2:1), children with metabolic abnormalities, urinary tract abnormalities, neuropathic bladder, enterocystoplasty.

Image Only 7% of stones occur in children < 16 years of age.

ETIOLOGY

Image Most stones are made of calcium, struvite, uric acid, or cystine that accumulates in the calyx or bladder.

Image Calcium stones: Radiopaque stones due to Image intestinal calcium absorption or Image renal absorption.

Image Struvite stones: Radiopaque stones composed of magnesium, ammonium, and phosphate. Most commonly secondary to chronic UTIs by urea-splitting bacteria such as Proteus.

Image Uric acid stones: Radiolucent stones associated with high serum uric acid levels, such as hyperuricosuria, Lesch-Nyhan syndrome, after chemotherapy, myeloproliferative disorders, and inflammatory bowel disease.

Image Cystine stones: Radiopaque stones associated with cystinuria, an auto-somal-recessive disorder causing decreased absorption of dibasic amino acids (cystine, lysine, arginine, and ornithine) by the renal epithelial cells.


Image

Metabolic disorders are often the cause of pediatric stones.



Image

Hypercalciuria is the most common metabolic cause of stones.


SIGNS AND SYMPTOMS

Image Microscopic or gross hematuria.

Image Urinary tract obstruction.

Image Abdominal/flank pain radiating to the genitalia (renal colic).

Image Recurrent UTIs.

DIAGNOSIS

Image Plain abdominal x-ray will show radiopaque stones (calcium and struvite). Ninety percent of stones are radiopaque.

Image Abdominal CT can be better at detecting stones and will also yield information on the presence of hydronephrosis.


Image

The most sensitive test for identifying stones in the urinary system is a noncontrast helical CT scan.


TREATMENT

Image Pain management: NSAIDs are mainstay; opiates occasionally needed.

Image IV hydration.

Image Remove calculi if they are > 5–6 mm via urethral stent or lithotripsy, especially if they are associated with obstruction and hydronephrosis.

Image Calcium stones: Treat with thiazide diuretic to reduce renal calcium excretion or potassium citrate, an inhibitor of calcium stones.

Image Struvite stones: Treat with antibiotics to prevent recurrence of bacterial infections.

Image Uric acid stones: Treat with allopurinol and urine alkalization.

Image Cystine stones: Treat with D-penicillamine to chelate cystine.

URINARY TRACT INFECTION (UTI)

Image

A 2-month-old male infant presents with fever, vomiting, and Image fluid intake. A UA reveals 100 WBCs. Think: E coli UTI.

The initial manifestations may be nonspecific and may include irritability, fever, and vomiting. E coli is the most common organism in children of all ages. Urinalysis may show positive urinary leukocyte esterase, positive urinary nitrite, pyuria (> 5 WBC/hpf) and bacteriuria.

Image

A 7-year-old girl presents with urinary urgency, frequency, suprapubic pain, and no flank pain or mass. UA shows many leukocytes, 2–5 RBCs, and no protein or casts. Think: Next step—urine culture.

Older children with UTI are more likely to develop localizing symptoms such as frequency, dysuria, and abdominal or flank pain. The definitive diagnosis of UTI requires a positive urine culture from a specimen obtained with sterile techniques. An appropriately collected urinary specimen is critical to make the diagnosis of UTI.

Image

A hospitalized 6-month-old infant with a UTI remains febrile after adequate IV antibiotic treatment. Think: The next most appropriate diagnostic procedure is a renal US.

The classic clinical manifestations of upper UTI include fever and flank pain. The persistence of fever despite antibiotics is suggestive of upper UTI (pyelonephritis). Febrile UTI in children may indicate either an underlying anatomic abnormality or vesicoureteral reflux (VUR). Ultrasound evaluation may detect underlying condition that predisposes the infant or child to infection.

DEFINITION

Image Infection of the urinary system by bacterial pathogens. UTIs are often ascending infections from fecal/colonic flora.

Image The most common bacteria are E coli, followed by Klebsiella, Proteus, enteroccci, and Staphylococcus saprophyticus (among female adolescents).

Image UTIs are more common in males in the first year of life and more common in females afterwards.

Image UTI occurs in 3–8% of girls and 1–2% of boys.


Image

Consider nosocomial UTIs with Pseudomonas and methicillin-resistant Staphylococcus aureus in institutionalized or recently hospitalized patients.


PREDISPOSING FACTORS

Image Female.

Image Uncircumcised male.

Image Vesicoureteral reflux/anatomic abnormalities.

Image Toilet training (wiping from back to front).

Image Tight clothing.

Image Bubble baths.

Image Nylon panties, bathing suit.

CLASSIFICATION OF UTIS

Image Pyelonephritis: Infection of the kidney characterized by abdominal or flank pain, fever, malaise, nausea, vomiting, and diarrhea.

Image Cystitis: Infection of the bladder. Common symptoms include dysuria, urgency, frequency, suprapubic pain, incontinence, and malodorous urine. Cystitis does not cause fever.

Image Asymptomatic bacteriuria: Presence of > 100,000/mL of a single bacterial organism on two successive urine cultures in a patient without any UTI-like symptoms.

SIGNS AND SYMPTOMS

Symptoms vary with age:

Image Neonates: Failure to thrive, feeding irregularities, diarrhea, vomiting, fever, hyperbilirubinemia.

Image 1 month–2 years: Colic, irritability, gastrointestinal (GI) complaints.

Image > 2 years: Urgency, frequency, dysuria, abdominal and flank pain.

DIAGNOSIS

Image Gold standard: Urine culture. If child is not toilet trained, specimen should be obtained via suprapubic tap or catheterization.

Image Presence of > 100,000 colonies of a single bacteria or > 10,000 colonies in a symptomatic child or any bacterial growth from a properly obtained specimen.

Image Leukocytes > 5/hpf.

Image Hematuria.

Image White cell casts.

TREATMENT

Treatment varies depending on the age of the child:

Image Consider sepsis < 3 months of age with UTI.

Image 2 months–2 years: UTIs are often associated with bacteremia in this age group, and 10–14 days of parenteral antibiotics is the treatment of choice. Trimethoprim-sulfamethoxazole, fluoroquinolones, and amino-penicillins are effective.

Image Older children: 5–7 days of oral antibiotics.

Image Pyelonephritis: 14-day therapy of β-lactam/cephalosporin. Antibiotics given intravenously initially, then switched to oral when clinical improvement is seen.

Image Further investigations:

Image All children under the age of 5 and all male children should have a renal US to identify anatomic abnormalities including hydronephrosis, dilation of distal ureters, or bladder hypertrophy and to rule out pyelonephritis.

Image Voiding cystourethrogram (VCUG) is performed by placing a catheter through the urethra into the bladder and instilling a radionuclide testing agent until the bladder is full and the child voids. Images are taken to record reflux disease. Indications for VCUG:

Image Females < 5 years old with UTI.

Image Females > 5 years old presenting with second UTI.

Image All males.

Image Febrile UTI.

Image Some experts recommend waiting 4–6 weeks after febrile UTI is treated to obtain VCUG.

Image Indications for admission:

Image Toxic-appearing child.

Image Pyelonephritis.

Image Child cannot tolerate oral antibiotics.


Image

Perform a Gram stain on urine after obtaining a clean-catch specimen. A delay of 1–2 hours after receiving the specimen may cause bacterial multiplication and false positives.


VESICOURETERAL REFLUX

DEFINITIONS

Image Retrograde flow of urine from the bladder to the ureter and renal pelvis.

Image Reflux predisposes to (renal infections) pyelonephritis by facilitating the transport of bacterial from the bladder to the upper urinary tract.

Image Recurrent pyelonephritis can result in renal scarring and ESRD.

Image See Table 14-3 for grading of vesicoureteral reflux.

TABLE 14-3. Grading of Vesicoureteral Reflux

Image

EPIDEMIOLOGY

Image VUR is seen in up to 50% of children with pyelonephritis.

Image Eighty percent of children with reflux are female.

Image Average age of diagnosis: 2–3 years.

SIGNS AND SYMPTOMS

Most reflux is diagnosed by VCUG during a workup for a UTI.

DIAGNOSIS/GRADING

VCUG or radionuclide cystogram.

TREATMENT

Image The goal of treatment is to prevent pyelonephritis and renal injury.

Image Children with low-grade reflux are managed medically with low-dose antibiotic prophylaxis (one-fourth to one-third dose of trimethoprim-sulfamethoxasole or nitrofurantoin) and UA and cultures every 3–4 months.

Image Surgical therapy is performed in children with breakthrough UTI on antibiotic prophylaxis, unresolving reflux, and bilateral grade IV or V reflux.

OVARIAN/TESTICULAR TORSION

Image

A 15-year-old boy presents with severe pain in his right testicle. This occurred suddenly while he was playing basketball. A physical exam reveals a tender, swollen, firm testicle with a transverse lie. There is no cremasteric reflex on the right. Think: Testicular torsion.

Diagnosis is made mainly by clinical suspicion. Classical presentation includes nausea, vomiting, and severe acute testicular pain. An absent or decreased cremasteric reflex is the most sensitive physical sign for diagnosing testicular torsion. However, its presence does not exclude the diagnosis. Abnormal testicular orientation such as transverse lie is another clue. Doppler ultrasound is helpful in making the diagnosis and would show no blood flow. Immediate surgical exploration should be performed if the suspicion is high.

Image

A 16-year-old previously healthy boy experiences a sudden onset of abdominal and scrotal pain. A physical examination shows severe tenderness in the inguinal canal on the right, and the right side of scrotum is empty. A UA is within normal limits. Think: Testicular torsion of an undescended testicle.

Most undescended testes are found either in or just distal to the inguinal canal. Torsion may occur in an undescended testis. Torsion of testicle should be considered in a boy with inguinal pain and/or swelling with an undescended testis. The most effective management is an immediate operation. Early management of the undescended testes may avoid these complications.

Image

A 16-year-old boy presents with lower left abdominal pain and left testicular pain for 2 weeks. Palpation of the testes is normal except for isolated tenderness of the epididymis. Cremasteric reflex is normal. Think: Epididymitis.

Patients with epididymitis experience scrotal pain of gradual onset and the tenderness is localized to the epididymis. However, history and physical findings may not reliably differentiate torsion from epididymitis. Urinalysis may show pyuria. Congenital genitourinary anomalies may be present which predispose to recurrent infection.

DEFINITION

Twisting of the ovary or testicle on its respective vascular pedicle.

EPIDEMIOLOGY

Testicular torsion is the most common cause of testicular pain in boys > 12 years and is most often due to poor fixation of the testis inside the scrotum (bell clapper deformity) due to redundancy of the tunica vaginalis.

SIGNS AND SYMPTOMS

Image Ovarian torsion: Acute unilateral intermittent sharp lower abdominal pain.

Image Testicular torsion: Acute pain and swelling of the scrotum, absent cremasteric reflex. Testicle with horizontal lie.

DIAGNOSIS

Doppler US shows low blood flow but diagnosis should be made clinically to avoid delay in treatment.

TREATMENT

Image Manual detorsion, followed by surgical fixation (orchiopexy). Torsion is a surgical emergency.

Image Time is of the essence. The longer the ovary or testis remains torsed, the less the chance of salvaging it. Ninety percent of gonads survive if detorsion and fixation take place within 6 hours of symptom onset.

Image Often a bilateral condition, so opposite testes is also fixed to the posterior scrotal envelope during surgery.

POLYCYSTIC OVARIAN (PCO) SYNDROME/OVARIAN CYSTS

DEFINITION

Image PCO syndrome is the most commonly diagnosed ovarian cause of hirsutism.

Image Other causes of ovarian cysts include ovarian hyperthecosis.

PATHOPHYSIOLOGY

Image Anovulation:

Image Lack of characteristic hormonal fluctuations result in chronic anovulation and Image levels of progesterone due to the absence of a corpus luteum.

Image Unopposed estrogen results in irregular shedding of a hyperplastic endometrium.

Image Endometrial hyperplasia predisposes PCOS patients to endometrial carcinoma.

Image Elevated testosterone: Image levels of LH stimulate ovarian follicular theca cells to produce androgens, resulting in hirsutism.

SIGNS AND SYMPTOMS

Hirsutism, amenorrhea, anovulatory infertility, obesity, insulin resistance.

DIAGNOSIS

Image Elevated LH-to-FSH ratio of 3:1 (normal LH:FSH is 1.5:1)

Image US shows multicystic ovaries (20–100 cystic follicles in each ovary) resembling a “pearl necklace.”

TREATMENT

Image Ovarian suppression with combined estrogen/progestin oral contraceptive pills. The progestin component will help reduce endometrial hyperplasia.

Image Hirsutism can be treated with oral contraceptives, spironolactone, and electrolysis.

UNDESCENDED TESTES

DEFINITION

Image Failure of one or both testes to descend into the scrotum. The undescended testes are usually found in the inguinal canal, but some may be ectopic.

Image Cryptorchidism is the failure of the testes to descend by 6 months of age.

SIGNS AND SYMPTOMS

Image Cryptorchidism is associated with infertility, malignancy especially seminomas, hernias, and testicular torsion.

Image The risk of malignancy is Image even if the testes are surgically placed into the scrotum; however, repositioning the testes makes them accessible for periodic examinations.

Image Orchiopexy also helps to decrease the risk of testicular torsion by decreasing the mobility of the testis. Usually performed between 9 and 15 months of age.

TREATMENT

Image If testes are not palpated in the inguinal canal: Orchiopexy after age 12 months.

Image If testes are palpated in the inguinal canal: Hormonal therapy with luteinizing hormone–releasing hormone (LHRH) is controversial.


Image

PainFUL ulcers:

Chancroid

Herpes

PainLESS ulcers:

Lymphogranuloma venereum (LGV)

Syphilis


SEXUALLY TRANSMITTED DISEASES (STDs)

Image

A 15-year-old female presents to the ED with a fever for 1 day, dyspareunia, and vaginal discharge. She had unprotected sexual intercourse with a new male partner 2 weeks ago. Physical exam reveals adnexal tenderness, cervical motion tenderness, and a friable cervix. Think: Pelvic inflammatory disease.

Acute PID is a condition of young females. Risk factors include younger age at first intercourse and unprotected sex. The most common clinical features are lower abdominal pain, Image vaginal discharge, and adnexal tenderness. Empiric treatment for PID is recommended in sexually active young women with pelvic or lower abdominal pain if any one of the following minimum criteria is present (cervical motion tenderness, adnexal tenderness, or uterine tenderness).


Image

Urethral discharge:

Gonorrhea

Chlamydia

Trichomonas


Image

A 3-year-old girl presents with malodorous bloody vaginal discharge. Think: Foreign body.

Presentation: foul-smelling discharge or vaginal bleeding. Most common vaginal foreign body in children is toilet paper. A gentle examination should be performed. Complete history and focused physical examination are usually sufficient to make this diagnosis.


Image

“Whiff test”: Two drops of KOH mixed with the discharge and heated onto a slide produces a fishy smell. This is characteristic of both Trichomonas and bacterial vaginosis.


See Table 14-4.

EPIDEMIOLOGY

Image Sexually transmitted diseases affect ∼25% of adolescents.

Image In infants and children, detection of an STD is an important clue to sexual abuse.

RISK FACTORS

Image Sexual contact with person(s) with a history of STD.

Image Multiple sexual partners.

Image More than two sexual partners during previous 12 months.

Image Intercourse with new partner during last 2 months.

Image No contraception or use of nonbarrier methods.

Image Street involvement (eg, homelessness).

Image Injection drug use.

Image “Survival sex” (eg, exchanging sex for money, drugs, shelter, or food).

Image Men who have sex with men.


Image

Due to the high rate of concurrent gonorrhea infection with chlamydia infection (60%), treatment for gonorrhea should always be included with that for chlamydia (and vice versa).


SCREENING AND PREVENTION

Image All women should receive a Papanicolaou smear annually to screen for cervical dysplasia within the three years of first sexual experience or at the age of 21. In addition, screen all asymptomatic sexually active patients annually for HIV, herpes simplex virus (HSV), hepatitis B, and chlamydia.

Image Educate all children how to Image the risk of contracting STDs, such as limiting number of sexual partners, using condoms, having regular check-ups, and engaging in open discussions about STDs.

Image If sexual abuse is suspected, social services and law enforcement agencies must be contacted to ensure the child’s protection.

TABLE 14-4. Sexually Transmitted Diseases in Children

Image

Image

Image

Image

Image

PHIMOSIS/PARAPHIMOSIS

DEFINITION

Image Phimosis: Inability to retract the prepuce (foreskin) over the glans penis. Phimosis is normal in (boys) males younger than 3 years of age. In older males, phimosis is considered pathologic and may be due to the inflammation at the tip of the foreskin.

Image Paraphimosis: Inability to reduce to foreskin due to venous congestion of the distal foreskin. Paraphimosis can progress to arterial compromise Image penile infarction/necrosis and gangrene.

Image Risk factors for phimosis/paraphimosis:

Image Poor hygiene Image recurrent balanitis.

Image Repeated catheterization.

Image Forceful retraction of the foreskin resulting in scarring/phimosis.

Image Penile piercing.


Image

Do not force retraction of the foreskin in phimosis. This may Image paraphimosis.


SIGNS AND SYMPTOMS

Image Phimosis may cause urinary retention secondary to pain or obstruction of the urethra.

Image The most acute complication of phimosis is paraphimosis.

TREATMENT

Image Phimosis: Steroid cream applied to the foreskin or manual stretching to loosen the phimotic ring. Circumcision is recommended for chronic phimosis in children > 10 years old.

Image Paraphimosis: Lubrication and manual compression of the foreskin and glans. Superficial vertical incision of the ligating band may be needed in refractory cases. Treatment is directed at reducing penile edema and restoring the foreskin to its original position as paraphimosis is a urologic emergency.

HYPOSPADIAS

DEFINITION

Image Ventral opening of the urethra on the penile shaft due to incomplete development of the foreskin “dorsal hood.”

Image Hypospadias is sometimes associated with in vivo exposure to estrogens or antiandrogens.

Image Associated with cryptorchidism and chordee (congenital malformation in which the head of the penis curves downward or upward).


Image

It is important to not circumcise children with hypospadias, as the foreskin is used in the repair.


TREATMENT

Surgical repair at 6–12 months.

EPISPADIAS

Image Dorsal opening of the urethra on the penile shaft.

Image Associated with more serious congenital abnormalities such as bifid phallus, bladder, and/or cloacal exstrophy.

TREATMENT

Surgical repair recommended within first 2 months of life.



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