CRACKCast E174 – Genitourinary and Renal Tract Disorders

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This episode of CRACKCast covers Rosen’s Chapter 173, Genitourinary and Renal Tract Disorders. Torsion, phimosis, UTIs, stones, and priapism are some of the high-yield topics covered here.

Shownotes: PDF Here

Core Questions

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[1] List a DDx for priapism  and describe treatment.

Priapism is the engorgement of the dorsal corpora cavernosa, resulting in dorsal penile erection lasting more than 4 hours.

 Three main types:

  • Low flow (ischemic, painful!!!, “limb” threatening!)
    • Sickle cell disease (>50% of pts with SSD have at least one episode)
    • Malignancy (lymphoma; leukemia)
    • Medications
    • Cocaine / drugs of abuse
  • High flow (non-ischemic, not painful, scary!)
    • Trauma, AVM, congenital disease
  • Neurogenic (penis not threatened – harbinger of spinal cord injury)

MANAGEMENT:

LOW FLOW

***draw an ABG off the dorsal penis: if pH <7.25, PaCO2> 60, Pa02 < 30, and dark coloured blood = LOW flow*** 

  • Akin to COMPARTMENT SYNDROME OF THE PENIS
    • hydration,
    • pain control,
    • relief of urinary obstruction,
    • and treatment of underlying conditions.

Local anesthesia by a dorsal nerve block or ring block should be performed prior to (1) aspiration, followed by (2) intracavernous injection (ICI) of sympathomimetic drugs (phenylephrine preferred).

Remember = 2 and 10 o’clock are safe zones!

If no effect with 1 mL of dilute phenylephrine q 5 min after 1 hour, urology may consider placement of a surgical shunt.

HIGH FLOW / NEUROGENIC

  • Observation
  • Refractory cases need cavernosal artery surgery

 

[2] Describe the management of a paraphimosis.

ALWAYS A PROBLEM

  • Proximal foreskin cannot be returned to its anatomic position covering the glans penis, resulting in distal venous congestion.

Paraphimosis

  • can be caused by infection, masturbation, trauma, hair or clothing tourniquets, or failure to reduce the foreskin after a medical examination or procedure.

Paraphimosis is a urologic emergency with potential for arterial compression, penile necrosis, gangrene, and/or autoamputation. Hair tourniquet can mimic paraphimosis in the circumcised male.

Management:

  1. Pain control:
    1. topically, parenterally, and/or with a local dorsal penile nerve block or ring block or procedural sedation.
  2. Firm compression / methods to reduce edema
    1. Firm ACE wrap on the penis to encourage venous outflow
    2. Parent’s hand holding constant pressure on the penis
    3. placing the finger of a rubber glove filled with ice water over the glans and foreskin, sprinkling granulated sugar over the edematous tip, and injection of hyaluronidase into the edematous prepuce.
  3. Reduction
    1. Manual reduction using index fingers and thumbs (see figure in text)
    2. Needle fenestration
      1. edematous foreskin may be punctured several times circumferentially with a 25-gauge needle to decrease edema further.
    3. Dorsal band traction
      1. Dorsal band traction can be performed with Adson forceps applied directly to the band formed by the retracted foreskin and application of traction and countertraction to loosen the constriction.
    4. Dorsal slit procedure
      1. An emergency dorsal slit should be performed when these measures fail to reduce the paraphimosis. Two straight hemostats are applied to crush the foreskin at the 12 o’clock position perpendicular to the corona. After 2 minutes, the prepuce between the hemostats is sharply incised, releasing the constricting band of tissue. The incisions are approximated with 4-0 absorbable sutures. Circumcision should be performed at a later date.

Follow up – with urology if child is able to urinate. If there are any signs of cellulitis/ischemia/necrosis or the child is unable to urinate they should be admitted. 

[3] Describe the management of a phimosis. 

USUALLY NOT A PROBLEM

Inability to retract the foreskin in a patient where it was previously retractable.

Management:

  • Without glans ischemia/infarction: (able to urinate, no signs of infection)
    • Gentle retraction and good hygiene are mainstays of management. Retraction of the prepuce should not be forced, because this can lead to future adhesions and strictures. A 6- to 8-week course of topical corticosteroids (eg, 0.1% triamcinolone topical cream), applied to the outlet twice daily, may expedite the development of retractable foreskin.
  • WITH ischemia/infarction:
    • dorsal slit procedure, circumcision, preputial plasty, or balloon dilation may be necessary. Obstructive uropathy can occur secondary to severe stenosis.

[4] What is the pathophysiology of balanoposthitis? What is the most common bug in balanoposthitis?

Balanoposthitis, an inflammation that involves the glans and foreskin, occurs in approximately 5% of uncircumcised males.

Balanitis involves the glans penis only.

Balanoposthitis is usually secondary to poor hygiene, infection (bacterial and fungal), contact dermatitis, chemical irritation, or local trauma. Less commonly, a drug eruption, scabies infection, sexually transmitted infection (STI; eg, human papillomavirus [HPV], herpes), or nummular eczema may cause inflammation.

Infectious organisms are gram-negative and gram-positive, including group A beta hemolytic streptococci and, rarely, Neisseria gonorrhoeae and Chlamydia.

 Canadia – is the most common fungal cause.

Bacterial causes: In a study of uncircumcised children, the most common organisms found by age were E. coli (ages 0 to 2 years), enterococci (ages 3 to 6 years), and Staphylococcus aureus and group A beta-hemolytic streptococci (ages 7 to 12 years) [17]. (Uptodate)

[5] How is balanoposthitis managed?

  1. Avoid irritants
  2. Warm sitz baths
    1. May help to have child urinate in the bathtub
  3. Good hygiene
  4. Control inflammation/infection
    1. Topical antibiotics
    2. Topical antifungals
    3. Topical corticosteroids for contact dermatitis
      1. Topical corticosteroids (eg, hydrocortisone, 0.5%–1%) may help inflammation due to contact irritation. Candidal infections should be treated topically with antifungals (eg, clotrimazole, miconazole, nystatin). A blood glucose test should be considered in patients presenting with recurrent candidal balanoposthitis.
    4. Systemic abx for severe infections / STIs

[6] Describe the diagnosis and management of pediatric epididymitis and orchitis. 

Epididymitis:

  • Etiology varies by age and presence of structural abnormalities
  • Pre-adolescence:
    • Usually viral
    • Bacterial causes are rare and occur with structural abnormalities
  • Adolescent:
    • Consider STI’s as a cause
    • A urethral discharge may be present, particularly when the condition is secondary to an STI.

 Patients present with a painful edematous scrotum and tenderness at the epididymis. Nausea, vomiting, fever, and lower abdominal, scrotal, or testicular pain may be present. Infants and young children may present with isolated fever.

 Diagnosis:

  • U/A +/- culture
  • Capture first void and wait for results if suspicious of STI

Management:

Scrotal elevation, ice packs to the scrotal area, and pain medications are useful to control pain and inflammation.

Sexually active:

  • If urethral discharge is present, sexually active adolescents should be treated presumptively for both N. gonorrhoeae and C. trachomatis. Ceftriaxone (250 mg intramuscularly) and doxycycline (100 mg bid for 10 days) is preferred treatment. To increase compliance, azithromycin (1 g once) may be used instead of doxycycline, although there are little data on the use of azithromycin for chlamydial epididymitis. Follow-up for resolution of symptoms should occur if azithromycin used.
  • In children, non–sexually acquired epididymitis without evidence of a urinary tract infection may be managed expectantly without antibiotics.
  • Infants with or without positive findings on urinalysis and young children with positive urinalysis findings may be treated with cephalexin tid if a bacterial urinary tract infection is suspected.

Orchitis: 

  • Usually viral or bacterial testicular infection
  • Symptoms:
    • Tenderness, edema, swelling, discolouration of the scrotum
    • If there is urethral discharge think of epididymo-orchitis
    • Causes:
      • Paramyxovirus is most common, associated with mumps. Other causes include Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus or Streptococcus spp., Epstein-Barr virus, coxsackievirus, arbovirus, enterovirus, Brucella, granulomatous disease, and filariae.
  • Treatment:
    • Treatment of viral orchitis is aimed at pain control (scrotal elevation, nonsteroidal antiinflammatory drugs [NSAIDs], and possibly narcotics).
    • Bacterial:
      • Cover for gram-negative bacteria (eg, a third-generation cephalosporin).
      • urologist should be urgently consulted for a scrotal or testicular abscess.

[7] Describe the diagnosis and management of testicular torsion. 

Key points:

  • Can occur at any age – most commonly 12-18 yrs
  • Time sensitive dx! 10% salvage rate at 24 hrs!

Diagnosis:

  • Hx: acute constant scrotal pain, swelling, high riding testicle, with nausea and vomiting.
    • acute scrotal pain and swelling, an elevated testicle and, typically, absence of the cremasteric reflex. This reflex can be demonstrated by lightly stroking the skin of the inner thigh downward from the hip toward the knee.
      • The cremaster muscle on the ipsilateral side rapidly contracts and elevates the testicle.Although absent in the vast majority of cases, the presence of the cremasteric reflex does not preclude testicular torsion.
    • Abnormal (high-riding and transverse) epididymal and testicular position may also be noted, with left-sided torsions slightly more common than right.
    • Pain is typically constant, and the patient may have a history of a similar prior episode. Up to 90% of patients have associated nausea and vomiting.
    • Cryptorchidism (one or both testes are undescended) increases the risk of torsion and may present with abdominal or inguinal pain. Familial history and recent trauma may increase the risk of torsion
  • Imaging:
    • Emergent doppler ultrasonography of both testicles and spermatic cords.
      • 85-95% sensitivity

Management:

  • Immediate surgery – ideally no more than 12 hrs from onset of symptoms
    • Surgery should not be delayed while waiting for ultrasound
    • Followed by elective orchiopexy of the contralateral side to avoid recurrence.
  • Bedside manual detorsion may be performed with analgesia if operative repair is delayed. The testicle is rotated in an open book fashion as viewed from below, from medial to lateral, until detorsion is complete.
    • Torsion may cause ischemia at 180 degrees of rotation but typically occurs with 360 degrees of twisting. Up to one-third of patients may torse laterally; in these cases, manual reduction worsens torsion and its symptoms, and the procedure should be halted.
  • In causes where the testicle is no longer viable – an elective orchiectomy may be performed

[8] List common bacteria in peds UTI and describe treatment <2 months, 2M – 2 Yrs, > 2 Yrs.

Neonatal boys are more susceptible to UTI’s than girls but, beyond that, females are at higher risk.

 

< 2 monthsE coli

 

Klebsiella

 

Other pathogens

Infants younger than 2 months are more at risk for sepsis.

 

●      Most require admission and broad spectrum IV abx (ampicillin and cefotaxime)

●      Rosen’s suggests that some 29-60 day olds may be managed as outpatients if well – but this doesn’t seem common in our practice

●      The CPS statement doesn’t comment on this specifically

***up to 50% of UTI’s < 3 months are associated with bacteremia! These kids should be considered for a FSWU

 

 

2 months – 2 yrsE. coli!

 

Other pathogens

include Enterobacter, Proteus, Morganella, Serratia, and Salmonella spp.

 

PO abx for 7-10 days.

 

PO options:

●      Cefixime (drug of choice for first febrile UTI)

●      Amoxicillin

●      Clavulin

●      Cephalexin

See list below for more.

 

IV options:

●      Ampicillin and ceftriaxone

 

UTIs in this age group are considered to be upper tract disease processes, a 7- to 10-day course is recommended

Oral abx is the best option for well appearing children who are able to receive and tolerate every dose and have good follow up

(tough in children < 6 months of age)

 

 

No macrobid

 

Need an outpatient bladder, ureters, kidney ultrasound to exclude structural abnormalities

> 2 yrsE coli, and others (see above)3-day course of antibiotics, such as cephalexin or amoxicillin-clavulanate for cystitis.

 

7-14 days for pyelonephritis.

 

Avoid fluoroquinolones

 

[9] List 6 causes of renal mass – how should these be imaged initially?

Three things: hydronephrosis; cystic masses; solid masses

  • cystic lesions, such as those of polycystic kidney disease, or benign cystic nephroma
  • severe hydronephrosis resulting from obstruction or severe reflux.
  • Solid masses:
    • Wilms’ tumor, neuroblastoma, renal cell carcinoma, mesoblastic nephroma, and cystic neuromas, malignant rhabdoid tumour

Start with ultrasound!

 

[10] Give a differential diagnosis of proteinuria in children.

First determine (using dipstick or U/A) whether it’s mild or moderate.  Patients with moderate proteinuria (3+; equivalent to 300 mg/dL) should have additional testing, including the total serum protein, albumin, electrolyte, BUN, and creatinine levels, and urine culture.

Also, try to add on a random urine protein-to-creatinine ratio.

A urine Pr/Cr more than 3.0 mg/dL correlates to nephrotic syndrome. Children with elevated urine Pr/Cr levels should be referred to a nephrologist for a 24-hour urine collection for protein.

 Consider adding on an antistreptolysin O (ASO) titer can identify a previous streptococcal infection as the cause of the proteinuria. (PSGN)

Causes outside of trace/mild proteinuria: think glomerular vs. tubular.

 Glomerular causes include nephrotic syndrome, glomerulonephritis, and posttransplantation rejection. Transient causes of altered glomerular function include exercise, extreme cold or heat, fever, seizures, and stress.

Tubular causes of proteinuria include heavy metal poisoning, urinary tract infections, and diabetes, as well as an asymptomatic tubular proteinuria.

[11] What is the most common cause of proteinuria in children?

Usually we see trace or mild proteinuria (< 100 mg/dL):

Trace to mild proteinuria (1+ to 2+) is a common laboratory finding in young children and can represent benign conditions, such as exercise or mild dehydration or urinary tract inflammation/infection (cystitis).

Mild proteinuria (2+; equivalent to 100 mg/dL) requires no further investigation. Evidence of a UTI, such as WBCs or a positive leukocyte esterase or nitrite level, should be treated.

Causes outside of trace/mild proteinuria: think glomerular vs. tubular.

The #1 cause would be post-infectious (IgA nephropathy or PSGN)

[12] Provide a differential diagnosis of acute renal failure in children. What is the most common cause?

 Most common: prerenal AKI secondary to volume depletion.

Box 173.3: Cause of Acute Renal Failure in Children

Prerenal

  • Decreased intravascular volume or dehydration
    • Burns or hemorrhage
    • Third spacing
    • Sepsis
  • Decreased cardiac output
    • Cardiac shock
  • Decreased renal artery blood flow

Intrarenal

  • Glomerular disease
    • Poststreptococcal and other glomerulonephritis
    • Pyelonephritis
  • Systemic causes
    • Hemolytic-uremic syndrome
    • Henoch-Schönlein purpura or other vasculitides
    • Systemic lupus erythematosus
    • Sepsis or other causes of prolonged decreased perfusion
  • Toxins
    • Heavy metal poisonings, such as lead and gold
    • Myoglobin or hemoglobin deposits
    • Antibiotics such as aminoglycosides
    • Anticonvulsants such as phenytoin
    • Radiocontrast dyes

Postrenal

  • Obstructive lesions
  • Nephrolithiasis or tumor
  • Posturethral valves
  • Intra-abdominal tumor obstructing urinary flow
  • Infection
  • Renal vein thrombosis

[13] Describe the clinical presentation of glomerulonephritis in a child.

Here we are classically thinking about “PSGN” 

Poststreptococcal glomerulonephritis (PSGN) is one of the most common glomerulonephritides. PSGN is a sequelae of streptococcal pharyngitis and, less commonly, streptococcal skin infections.

PSGN is believed to result from the deposition of circulating immune complexes in the kidney. How those immune complexes develop is not completely understood. These immune complexes result in decreased glomerular filtration, allowing proteins to flow freely into the urine.

[14] Define hypertension in a child.

Systolic or diastolic blood pressure higher than 2 standard deviations (SDs) above the mean for age and gender.

Table 173.2: Blood Pressure Limits in Children 

AGE (yr)BLOOD PRESSURE: UPPER LIMIT (mm Hg)
SystolicDiastolic
0–211065
3–612070
7–1013075
1–1514080

 

[15] List causes of hypertension in a child.

Box 173.4: Causes of Hypertension in Children

Primary

  1. Essential hypertension

Secondary

Renal

  1. Glomerulonephritis
  2. Henoch-Schönlein purpura
  3. Pyelonephritis
  4. Obstruction or reflux
  5. Polycystic kidney disease
  6. Diabetic nephropathy
  7. Trauma
  8. Renal transplant or hemodialysis
  9. Tuberous sclerosis
  10. Systemic lupus nephritis

Endocrine

  1. Pheochromocytoma
  2. Cushing’s syndrome
  3. Congenital adrenal hyperplasia
  4. Corticosteroid treatment
  5. Hyperthyroidism
  6. Neuroblastoma
  7. Ovarian tumor

Cardiac

  1. Congestive heart failure
  2. Coarctation of the aorta

Vascular

  1. Hemolytic-uremic syndrome
  2. Kawasaki syndrome
  3. Renal artery thrombosis or stenosis

Neurologic

  1. Central nervous system tumor or infection
  2. Central nervous system trauma or abuse
  3. Increased intracranial pressure
  4. Guillain-Barré syndrome

Neoplastic

  1. Neuroblastoma
  2. Wilms’ tumor
  3. Pheochromocytoma
  4. Adrenal carcinoma

Drugs

  1. Corticosteroids
  2. Cocaine
  3. Sympathomimetics
  4. Oral contraceptives
  5. Phencyclidine
  6. Beta-blocker or clonidine withdrawal
  7. Lead, mercury

Others

  1. Iatrogenic fluid overload
  2. Volume overload from end-stage renal disease

[16] Llist 2 medical treatments for acute hypertensive crisis in children. 

Rare!

Kids < 10 yrs: BP > 160/105 – hunt for the signs of end organ damage!

Kids > 10 yrs: BP > 170/110 – go looking!

Big list to choose from; here’s two. (you may have other drugs easily accessible at your hospital). Goal is a 10-20% reduction in hours.

  • Labetalol
  • Hydralazine

[17] What are the two types of HUS? What are the typical presenting features?

  1. Primary – atypical HUS
  2. Secondary HUS

Primary results from complement dysregulation.

Secondary is a post-infectious/drug/idiopathic phenomenon.

 (eg, STEC, Shigella organisms, S. pneumoniae, Aeromonas, or HIV), drugs (eg, chemotherapeutic or transplant anti-rejection drugs), or other idiopathic causes (eg, pregnancy, lupus). UTIs have also been implicated.

Presentation:

Secondary HUS due to STEC presents with watery diarrhea, crampy abdominal pain, and occasionally fever. Within days of symptom onset, patients experience increasing abdominal pain, with 50% to 85% developing bloody stools.

 Patients may also develop toxic megacolon, ischemic colitis, intussusception, perforation, or delayed colonic stricture.

Patients with a pneumococcal cause for the HUS typically present with pneumonia or, less commonly, meningitis, bacteremia, sinusitis, or otitis media.

Up to 10% of patients will experience the triad of sudden onset hemolytic anemia, thrombocytopenia, and acute renal insufficiency, with possible progression to renal failure. Up to 60% of diarrhea-associated HUS cases require dialysis, and death or end-stage renal disease was found to occur in 12%.

 

Remember this is a hemolytic disease: The peripheral blood smear shows microangiopathic changes such as schistocytes, teardrop cells, helmet cells, microspherocytes, and burr cells.

[18] Describe the management of Hemolytic Uremic Syndrome (HUS) and Henoch Schonlein Purpura (HSP) in kids. 

HUSHSP
a microangiopathic hemolytic anemia, is one of the most common causes of acute kidney injury in children.

HUS is rare after 5 years of age,

 

Hypersensitivity small vessel vasculitis affecting the joints, GI system and skin.

Usually post URTI or group a strep infection (can be provoked by any virus)

 

classic HSP rash is usually diagnostic.

Watch for renal or abdominal complications.

These folks can become sick fast!

●      Aggressive supportive care

○      Correct electrolytes

○      Treat pancreatic failure

○      Treat seizures

○      Treat hypertension

●      No role for antibiotics (enhance release of verotoxin)

Except: Pneumococcal-associated HUS often presents with pneumonia and should be treated

●      Early consideration of dialysis

●      PRBCs if Hgb < 60

●      ?consideration of plasmapheresis if presenting with stroke

●      ?eculizumab if primary HUS

●      Controversial

●      NSAIDs for arthralgias (assuming no renal involvement)

●      Corticosteroids may help abdominal pain resolve; but do NOT prevent abdominal or renal complications

●      IVIG if severe renal impairment

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Wisecracks

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[1] List three complications of circumcision.

Circumcision prevents phimosis, paraphimosis, recurrent balanoposthitis, and decreases urinary tract infections, sexually transmitted disease transmission (including human immunodeficiency virus [HIV]), and penile cancer. An American Academy of Pediatrics task force has concluded that the benefits of circumcision outweigh the risks.

  • Infection
    • Local, systemic
    • UTI
  • Bleeding
    • Minor
    • Major bleeding may raise suspicion for a blood dyscrasia
  • Pain
  • Urinary problems:
    • Stricture formation
    • Urinary retention
  • Post-circumcision phimosis

[2] Describe approaches to penile entrapment and tourniquet states. 

  • Depend on the object
    • Rings:
      • Mineral oil; string wrap technique; ring cutters
    • Zippers:
      • Mineral oil; cutting median bar of zipper

[3] Which side is a varicocele concerning and why?

A varicocele is a collection of venous varicosities of the spermatic veins in the scrotum caused by incomplete drainage of the pampiniform plexus. Varicoceles are more pronounced when upright. Varicoceles are described as a “bag of worms” in appearance and on palpation.

  • Normally occurs on the left side
  • Any RIGHT sided varicocele should raise suspicion for neoplasm – and patient should be considered for imaging to investigate for retroperitoneal neoplasm (U/S, CT, MRI) 

Concerning features for varicoceles:

  1. Sudden onset
  2. Right sided
  3. Do not decrease in size when supine.

[4] Other than cystitis and pyelonephritis, list 6 other causes of pediatric dysuria. 

  • Stones – kidney
  • Strictures – labial adhesions
  • STI’s – balanitis or vaginitis
  • Stuff – retained foreign bodies
  • Stuck – labial adhesions, phimosis
  • Sad situation – abuse
  • Self stimulation
  • Sticky tape – pin worms
    • Or Scratching while sleeping (just treat it empirically in real life if the dx is highly suspected).

See Box 173.1: Cause of Dysuria in Children

Infection

  1. Urinary tract infection, including cystitis and pyelonephritis
  2. Vaginitis resulting from Gardnerella, Trichomonas, Candida, or sexually transmitted organisms
  3. Pinworms
  4. Balanitis

Irritation

  1. Bubble bath, new soaps, or douches
  2. Vaginal foreign body, such as retained toilet paper

Trauma

  1. Sexual or physical abuse
  2. Straddle injury (unintentional)
  3. Self-stimulation or masturbation

Other

  1. Labial adhesions
  2. Renal stones or hypercalciuria

[5] List 10 causes of hematuria in kids. 

Red blood cells (RBCs) can enter the urinary tract from inflammation, infection, trauma, or anatomic abnormalities, anywhere from the glomerulus to the urethra. Microscopic hematuria is defined as more than 5 RBCs/mm3; macroscopic or gross hematuria is the presence of blood or clots visible to the naked eye.  

From glomerulus to ureters! Think structurally or think:

  • Renal
  • Extra-renal (including mimickers)
  • Systemic

Box 173.2: Cause of Hematuria in Children

Extrarenal

  1. Trauma
  2. Meatal stenosis or posterior urethral valves
  3. Exercise
  4. Menstruation or rectal bleeding
  5. Foreign bodies
  6. Cystitis, urethritis, or epididymitis

Intrarenal

  1. Pyelonephritis
  2. Renal or bladder stones or tumors
  3. Poststreptococcal or idiopathic glomerulonephritis
  4. Acute interstitial nephritis
  5. Acute tubular necrosis
  6. Basement membrane glomerular disease
  7. Renal vein or artery thrombosis
  8. Recurrent familial hematuria
  9. Polycystic kidney disease

Systemic

  1. Alport syndrome nephritis
  2. Henoch-Schönlein purpura
  3. Systemic lupus erythematosus
  4. Hemolytic-uremic syndrome
  5. Infectious mononucleosis
  6. Sickle cell disease or other hemoglobinopathies
  7. Bacterial endocarditis or artificial cardiac valves
  8. Bleeding disorders, warfarin, or aspirin
  9. Medications such as amitriptyline or chlorpromazine, radiocontrast dyes
  10. Munchausen syndrome or factitious

[6] List 5 false indicators of hematuria (review!). 

Urine with lysed RBCs or myoglobin from muscle breakdown tests positive for hemoglobin, yet will not contain RBCs. Certain drugs or foods, such as phenothiazines, ibuprofen, beets, and blueberries, can cause reddish urine. In neonates, urate crystals can cause a benign red-tingedurine in the diaper, also termed brick dust urine.

[7] List 6 causes of nephrotic syndrome in kids. 

Nephrotic syndromes are kidney diseases that result in significant proteinuria, hypoproteinemia, and edema.

 

Although hypoalbuminemia defines the diagnosis of nephrotic syndrome, levels of other important proteins such as immunoglobulins can also be reduced by the disease.

Usually broken down by two age groups:

  • < 5 yrs – likely primary nephrotic syndrome – due to minimal change disease
  • > 5 yrs – usually due to a secondary/systemic disease
    • PSGN
    • Lupus

 Here’s that list of causes:

  • Primary proteinurea due to minimal change disease
    • primary nephrotic syndrome (no gross hematuria or elevated creatinine level, normal complement levels, and no evidence of extrarenal causes such as a malar rash)
  • Secondary causes:
    • IgA nephropathy
    • PSGN
    • HUS
    • HSP
    • Lupus
    • Goodpasture’s disease
    • Wegener’s granulomatosis
    • Alport syndrome

 What is “nephrotic range” proteinuria?

  • Nephrotic-range proteinuria is a daily excretion of more than 3.5 g of protein/1.73 m2 or more than 50 mg/kg, corresponding to 3+ or 4+ on the urine dipstick.

[8] List 5 complications of acute renal failure in children.

  • edema
  • ascites,
  • significant hypertension (>99th percentile for age and height) resulting from glomerulonephritis,
  • marked impairment of renal function (>50% over normal) should be hospitalized.
  • pulmonary edema
  • cardiac arrhythmias

 Let’s go through the life threats again:  severe hyperkalemia, hyponatremia, pulmonary edema or fluid overload, hypertensive encephalopathy, septic shock from renal obstruction and infection, and seizures from metabolic abnormalities or encephalopathy.

[9] How does E. coli cause HUS? Which strain of E. coli is the concerning one?

The BIG concern with HUS is acute renal failure!

Renal compromise is due to renal vascular endothelial injury, often induced by viral or bacterial agents.

RBCs are injured within narrowed blood vessels, resulting in a microangiopathic hemolytic anemia. Platelets, complement, and fibrin are deposited in the glomerular lumen, resulting in thrombocytopenia, a decrease in the glomerular filtration rate, and renal failure.

Most common cause is Shiga toxin (verotoxin)–producing E. coli (STEC), specifically serotype O157:H7. 

Spread fecal orally or from contaminated foods.

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This post was copyedited and uploaded by Owen Scheirer.

Adam Thomas

CRACKCast Co-founder and newly minted FRCPC emergency physician from the University of British Columbia. Currently spending his days between a fellowship in critical care and making sure his toddler survives past age 5.
Chris Lipp is one of the founding Fathers for CrackCast. He currently divides his time as an EM Physician in Calgary (SHC/FMC) and in Sports Medicine (Innovative Sport Medicine Calgary). His interests are in paediatrics, endurance sports, exercise as medicine, and wilderness medical education. When he isn’t outdoors with his family, he's brewing a coffee or dreaming up an adventure…..