Nephrology/Urology Flashcards
(279 cards)
1
Q
How do you differentiate true from pseudohyponatremia?
A
Measure serum osmomalility
True hyponatremia should be hypoosmolar
2
Q
Name 3 conditions that can cause pseudohyponatremia
A
IVIg
Multiple myeloma
Hypertriglyceridemia
Hypercholesterolemia
3
Q
Name 6 conditions in the differential of hyponatremia
A
1) Hypovolemic Hyponatremia:
-Extra-Renal Losses:
• Vomiting/Diarrhea
• Sweat (e.g. CF)
• Burns
-Renal Losses:
• Diuretics (thiazides, loop, osmotic)
• ATN
• ARPKD
• Cerebral salt wasting
• RTA (Proximal aka typeII)
• Lack of aldosterone (e.g. CAH, pseudohypoaldosteronism)
2) Euvolemic Hyponatremia: • SIADH • Hypothyroidism • Glucocorticoid deficiency • Water intoxication → excess IVF, feeding infants water, swimming lessons, tap water enema, diluted formula, psychogenic polydipsia, marathon running w/ excessive drinking, beer potomania
3) Hypervolemic Hyponatremia: • Nephrotic syndrome • CHF • Liver cirrhosis • Sepsis • Protein-losing enteropathy
4
Q
Below what Na level are seizures likely?
A
Na <120
5
Q
What test is most helpful in determining cause of hyponatremia?
A
- Urine Osmolality
- If Osm>100, ADH present, check urine Na
- If Osm<100-water intoxication, let them pee it out - Urine Na
- <20=dehydrated, appropriate ADH response (treat with saline)
- >40=inappropriate ADH response (treat with lasix or hypertonic saline)
6
Q
How quickly should you correct Na to avoid central pontine myelinolysis?
A
Avoid correcting the [Na] by >12 mEq/L in 24h or >18 mEq/L in 48h
7
Q
How do you treat seizures secondary to hyponatremia?
A
3% NaCl bolus (3-5 ml/kg)
8
Q
List 3 causes of SIADH
A
CNS lesion
Post-op
Malignancy
Medications (vincristine, cyclophosphamide, carbamezipine
9
Q
List 6 causes of hypernatremia
A
Excessive Sodium:
• Improperly mixed formula
• Seawater ingestion
• Hyperaldosteronism
Water Deficit:
• Diabetes Insipidus (nephrogenic or central)
• Increased insensible losses – e.g. prems, phototherapy, radiant warmers
• Inadequate intake – e.g. breastfeeding, neglect
Water + Sodium deficits: • GI losses (vomiting/diarrhea) – uncommon • Burns/sweating • Polyuric phase of ATN • DM
10
Q
What is the most important investigation in hypernatremia?
A
Urine osmolality (if kidneys working, should be high >800 mmol/L)
11
Q
What brain lesion are patients with rapid hypernatremia at risk of?
A
CSVT
12
Q
Rapid correction of hypernatremia can lead to….
A
Cerebral edema
13
Q
Rapid correction of hyponatremia can lead to…
A
Central pontine myelinosis
14
Q
How do you calculate free water deficit?
A
Free water deficit (mL) = 4x weight (kg)xdesired change in [Na] (mmol/L)
15
Q
List 10 causes of hyperkalemia
A
1. Spurious: • Hemolysis • Thrombocytosis/Leukocytosis 2. Increased Intake: 3. Transcellular Shift • Acidosis • Rhabdomyolysis/Exercise • TLS • Tissue necrosis • Succinylcholine • Hemolysis/bleeding • B-blockers • Hyperosmolality • Insulin deficiency • Malignant hyperthermia 4. Decreased Excretion • Renal Failure • Adrenal Disease (e.g. Addison, CAH) • Hypoaldosteronism • Renal tubular disease (e.g. pseudohypoaldosteronism, Bartter syndrome) 5. Medications: • ACE inhibitors, Angiotensin II blockers • Diuretics (potassium sparing) • NSAIDs • Trimethoprim • Heparin • Calcineurin inhibitors • Yasmin28
16
Q
List 6 features on ECG in hyperkalemia
A
- Peaked T waves
- ST-segment depression
- Increased PR interval
- P wave flattening
- QRS widening
- Ventricular fibrillation/Asystole
17
Q
List 3 options for management of hyperkalemia
A
A. Stabilize the heart to prevent life-threatening arrhythmias
o Calcium to stabilize the cardiac cell membrane
B. Shift K+ intracellularly
o Ventolin
o Insulin + Glucose
o Bicarbonate
C. Remove potassium from the body o Stop all sources of K+ o Loop diuretic (e.g. Lasix) o Kayexelate o Dialysis
18
Q
List 5 causes of hypokalemia
A
1, Spurious: • Leukocytosis 2, Decreased Intake: • Anorexia nervosa 3. Transcellular Shift • Alkalosis • Insulin • alpha-Agonists • Refeeding syndrome • Drugs/Toxins • Hypokalemic periodic paralysis/Thyroxic periodic paralysis 5. Extra-Renal Losses • Diarrhea • Sweating • Laxative abuse 6. Renal Losses: • DKA • Medications, e.g. diuretics, penicillin • Tubular disorders • CF • Chloride-losing diarrhea • Lots of different syndromes/adrenal/renal disorders+malignancies (e.g. Bartter Syndrome, Gitelman Syndrome, Liddle Syndrome)
19
Q
Describe the clinical features of Barrter’s syndrome
A
AR
Impaired NaCl reabsorption, volume depletion
Low BP
Hypokalemia
Metabolic alkalosis
Can be developmentally N or have FTT, delays
20
Q
Describe the clinical features of Liddle’s syndrome
A
AD Severe HTN Metabolic alkalosis Hypokalemia Normal/low aldosterone
21
Q
List 3 ECG changes in hypokalemia
A
- Flattened T waves
- ST-segment depression
- U wave
- Ventricular fibrillation/Torsades
22
Q
List 3 medications that can cause renal stones
A
Topamax Lasix (esp in neonates) Ifosfamide Indinavir Allopurinol Acetazolamide
23
Q
When should you think about urinary tract infection in a child <3 years?
A
Fever (>39) with no source
Especially highly likely if fever >39 for >48H!
24
Q
When should you think about UTI in a child >3 years?
A
Only if urinary symptoms
25
After what age is it unusual for males to have a UTI?
>3 years
| Unless urinary tract abnormalities or instrumentation
26
For cystitis, what is a reasonable duration of antibiotics?
2-4 days
27
Within what time frame should renal ultrasound be obtained in first febrile UTI?
<2 weeks
28
What are the disadvantages of performing VCUG?
Exposure to radiation
Discomfort to child
Risk of causing UTI
29
List 5 risk factors for recurrent UTI
```
Uncircumcised (esp if boy >1 year)
VUR
Voiding dysfunction
Obstructive uropathy
Constipation
Neurogenic bladder
```
30
What is the triad of prune belly syndrome?
```
Deficient abdominal muscles
Undescended testes (usually intrabdominal)
Urinary tract abnormalities
```
31
What are the renal complications of Prune Belly syndrome?
```
Hydronephrosis
Massive dilation of ureters
High grade VUR
Dysplastic kidneys
PUV
```
32
What are the renal complications of Prune Belly syndrome?
```
Most common-progression to CKD (50%)
Hydronephrosis
Massive dilation of ureters
High grade VUR
Dysplastic kidneys
PUV
```
33
List causes of obstructive uropathy
1. PUV-most common cause of severe obstruction
2. Urtheral strictures
3. Ureterocele
4. Ectopic ureter
5. UPJ obstruction-most common
34
List causes of hydronephrosis
1. PUV-most common cause of severe obstruction
2. UPJ obstruction-most common obstructive uropathy
3. VUR
4. Other obstructive uropathies:
- Urtheral strictures
- Ureterocele
- Ectopic ureter
- Congenital megaureter
5. MCDK
35
What is the classification of severity of hydronephrosis in 3rd trimester?
Mild: <9 mm
Moderate: 9-15 mm
Severe: >15mm
36
When should you perform an postnatal ultrasound for hydronephrosis?
If severe and bilaterally (>15 mm)-within 2 days
If severe and unilateral-after 2 days
If not severe-after 7 days (between 1-4 weeks of age)(fluid shifts underestimate the degree of hydronephrosis)
37
If post natal ultrasound shows mild hydronephrosis (RPD <9mm), what should you do?
U/S at 3 months
38
If post natal ultrasound shows moderate/severe hydronephrosis (RPD>9mm), what should you do?
VCUG
39
When do you start prophylactic antibiotics for antenatal hydronephrosis?
If severe (RPD >15 mm) in 3 rd trimester while awaiting ultrasound
40
What is the best test to detect renal scarring?
Renal nuclear scan (DMSA)
41
How does urethral prolapse typically present?
Black girls 1-9yo
Presents as bloody spotting on the underwear, dysuria or perineal discomfort
42
How do you treat urethral prolapse?
Estrogen cream
| Surgery
43
What is a paraurethral cyst?
Results from retained secretions in the Skene glands secondary to ductal obstruction
44
What is the natural history of paraurethral cyst?
Present at birth, and regress in size during the first 4–8 wk
If not, surgical drainage
45
How does prolapsed ectopic ureterocele present?
Cystic mass protruding from the urethra
46
What investigation should you order for ectopic ureterocele?
Ultrasonography should be performed to visualize the upper urinary tracts to confirm the diagnosi
47
List risk factors for renal vein thrombosis in infants
```
Asphyxia
Dehydration
Sepsis
Thrombophilia
Maternal diabetes
```
48
List risk factors for renal vein thrombosis in kids
```
Nephrotic syndrome
CHD
Thrombophilia
Sepsis
Post-kidney transplant
```
49
How does renal vein thrombosis present?
```
Sudden onset gross hematuria
Flank mass
Flank pain
Hypertension
Oliguria
```
50
Treatment of renal vein thrombosis
Supportive
Correction of fluid and electrolyte imbalance
Treatment of HTN
If refractory HTN-nephrectomy
51
How do you distinguish between AR and AD PCKD?
AD
- Normal at birth
- Cysts in kidneys, liver, pancreas, spleen
AR
- Large echogenic kidneys on fetal U/S
- Oligohydramnios
- Large cysts
- Severe HTN and pulmonary hypoplasia
52
How does ARPCKD typically present?
Neonates/infants!
```
Large kidneys and cysts
Hepatic fibrosis
Bilateral flank mass in neonates
Oligohydramnios-pulmonary hypoplasia
HTN within first few weeks of life
ESRD
```
53
What are the liver complications of ARPCKD?
```
Bile duct proliferation
Hepatic fibrosis
Ascending cholangitis
Varices
Hypersplenism
```
54
Genetics of ADPCKD
PKD1, PKD2 encoding polycystin
55
How does ADPCKD typically present?
Symptomatic in 4th/5th decade! (rarely in neonates)
Enlarged kidneys (but not usually at birth)
Hematuria
Flank pain
Abdominal masses
HTN
56
Where can you have cysts in ADPCKD?
Liver
Spleen
Pancreas
Ovaries
57
List complications associated with ADPCKD
Intracranial aneurysms
Mitral valve prolapse
Renal cell carcinoma
58
How do you diagnose ADPCKD?
U/S
| Parent U/S
59
What is multicystic dysplastic kidney?
Usually unilateral
Not typically inherited
Kidney replaced by non-functioning cysts
60
List associations with multicystic dysplastic kidney
Contralateral hydronephrosis (30%)
VUR (15%)
Risk of Wilms tumour***
HTN (1%)
61
What is the most common cause of neonatal abdominal mass?
MCDKD
62
What investigations do you order for MCDKD?
U/S-multiple cysts that do not communicate, no renal parenchyma
DMSA scan-will show no function; helps differentiate from severely obstructed kidney
VCUG if significant hydronephrosis in contraleteral kidney
63
Follow up of patients with MCDKD
Serial US
Monitor BP
Monitor function of other kidney
64
Indications for nephrectomy in MCDKD
Enlargement of cysts
Increase in stromal core
Hypertension
65
In renal agenesis, what happens to contralateral kidney?
Compensatory hypertrophy
| Low grade VUR
66
What test to confirm diagnosis of renal agenesis?
DMSA
67
List conditions associated with renal cysts
```
Autosomal recessive polycystic kidney disease
Autosomal dominant polycystic kidney disease
Hereditary cystic disease with interstitial nephritis
Cerebello-ocular-renal syndromes
Cystic dysplastic kidneys
Joubert syndrome
Juvenile nephronophthisis
Meckel-Gruber syndrome
VATER syndrome
Trisomy 21, 18, 13
Tuberous sclerosis
VonHippel-Lindau syndrome
Orofacial digital syndrome
Bardet-Biedel syndrome
Simple benign cysts
Autosomal dominant hereditary angiopathy with nephropathy
```
68
Features of hyperaldosteronism
```
Hypertension
Hypokalemia
Metabolic alkalosis
Plasma aldosterone/renin is high
HTN
```
69
Inheritance of Bartters syndrome and Gitelman syndrome
AR
70
What is the defect in Bartters syndrome?
LIKE LASIX!
| Defect in sodium and chloride resorption in the loop of Henle
71
What is the defect in Gitelmans syndrome?
LIKE THIAZIDE!
| Defect sodium and chloride transporter in the distal tubule
72
What are the features of Bartters and Gitelman syndrome and how are they different?
```
Both have:
Urinary loss of Na and chloride
Secondary hyperaldosteronism
Hyperreninemia
Hypokalemia
Metabolic alkalosis
Normal BP
Polyuria polydipsia (decreased urine concentrating ability)
```
Bartters:
- Dysmorphic features
- Growth and mental retardation
- Hypercalciuria
Gitelman:
- Less growth failure
- Hypocalciuria and hypomagnesemia
73
Fluid requirement formula
Insensible (400 x m2) + urinary losses
74
Differential diagnosis of daytime urinary incontinence
Overactive bladder-most common cause of daytime incontinence
Neurogenic
- Spina bifida
- Spinal cord injury
Anatomic
- Ectopic ureter
- Bladder outlet obstruction
Functional
- Overactive bladder
- Voiding postponement and underactive bladder
- Vaginal voiding
- Non-neurogenic neurogenic bladder/Dysfunctional voiding
75
Investigations for daytime incontinence
```
Urinalysis
C&S
Bladder diar
Validated symptom assessment scores
Imaging (Renal u/s, bladder scan (post void residual)
VCUG
Urodynamic studies
```
76
What is the pathophysiology of overactive bladder
Abnormal bladder contraction during the filling phase
77
What is the hallmork symptom of overactive bladder?
Urgency
Urge incontinence
Vincent's curtsy
78
Treatment for overactive bladder
```
Treat constipation
Treat UTIs
Timed voiding (q1.5-2hrs)
Biofeedback (Kegel exercises/pelvic floor exercises)
Anticholinergics
Alpha adrenergic blockers
```
79
What is non-neurogenic neurogenic bladder/dysfunctional voiding?
Failure of the external sphincter to relax during voiding
80
Hallmark of non-neurogenic neurogenic bladder/dysfunctional voiding?
Stacatto stream
81
What investigations should you do for suspected dysfunctional voiding?
MRI spine
| Urodynamic studies
82
List complications of non-neurogenic neurogenic bladder/dysfunctional voiding
VU reflux
Hydronephrosis
Renal insufficiency
83
What is vaginal voiding?
Incontinence usually occurs after urination after the girl stands up
84
What is the most common cause of vaginal voiding?
Labial adhesion
Others:
Don't separate legs widely during urination
85
What symptoms would indicate ectopic ureter as cause of incontinence?
Constant dripping all da
86
Causes of neuropathic bladder
Spina bifida
Spinal trauma
Spinal tumour
Sacrococcygealteratoma
87
How do you treat neuropathic bladder?
Usually treated around 4yr
| Clean intermittent catheterization
88
Features of daytime frequency syndrome of childhood
Severe urinary frequency (q10-15min)
| No dysuria, incontinence
89
In what group is daytime frequency syndrome of childhood most common
Boys 4-6 (after toilent training)
| Emotional stress!
90
What is the natural history o f daytime frequency syndrome?
Resolve in 2-3 months
91
What is the definition of secondary enuresis?
When incontinence reoccursa fter at least 6 months of continence
92
Diagnostic criteria of nocturnal enuresis
Regular (more than twice per week) wetting persists ≥ 5 years of age.
93
Non pharmacologic measure to manage nocturnal enuresis (CPS)
Avoid caffeine-containing foods and excessive fluids before bedtime.
Have the child empty the bladder at bedtime.
DO NOT PUNISH CHILD
94
When should you treat nocturnal enuresis? (CPS)
When it is distressing to the child
95
What is the purpose of alarm therapy in nocturnal enuresis? (CPS)
To teach the child to respond to a full bladder while asleep
96
What is the success of alarm therapy dependent on? (CPS)
Child being motivated
Willingness of child and parent to be awoken
Requires a commitment from other siblings
97
Above what age is alarm therapy most effective? (CPS)
>7 years
98
How long should a therapeutic trial of alarm system be continued? (CPS)
3-4 months
May take 1-2 months to start seeing an imporvement
99
How long after achieving bladder control should alarm therapy be continued? (CPS)
Continue until there have been 14 consecutive dry nights.
100
What is cure rate for alarm therapy? (CPS)
Just under 50%
101
When should DDAVP be used for enuresis management? (CPS)
Useful for short-term treatment i.e. camp, sleepovers
102
Side effects of DDAVP
Abdominal pain
Headache
Epistaxis
Dilutional hyponatremia
103
When should fluid intake be limited when taking DDAVP? (CPS)
Fluid intake be limited to eight ounces (240 mL) from 1 hour before to 8 hours after administration of desmopressin
104
When should imipramine (TCA) be used in treatment of nocturnal enuresis? (CPS)
Age >6
Distressed,older children if other treatments unsuccessful or are contraindicated
Parents are judged to be reliable
Parents counselled about safe storage of the medication
Needs 2 week therapeutic trial
105
Causes of nocturnal enuresis
Maturational delay
Genetics (chromosome 13q)-esp PRIMARY enuresis
Detrusor overactivity
Small bladder capacity (constipation)
106
What counseling should you give a parent re: nocturnal enuresis in a child <5 years regarding natural history?
Should be regarded as a variation in the development of normal bladder control.
Improves with age
107
When does foreskin typically become retractable?
50% by 6 years
| 95% by 17 years
108
What is phimosis?
Scarring and thickening of the foreskin that prevents retraction back over the glans
109
List causes of phimosis
Recurrent posthitis/balanoposthitis
Recurrent paraphimosis
Lichen sclerosis
110
Treatment of phimosis
1) Topical steroid and gentle retraction
| 2) Circumcision if fails
111
Advantages of circumcision
Prevention of phimosis
Decrease in early UTI (in first few months of life)
Decrease in UTI in males with risk factors
Decreased acquisition of HIV, HSV, HPV
Decreased penile cancer
Decreased trichomonas, bacterial vagniosis, cervical cancer risk in female partners
112
Short term complications of circumcision
Post procedural pain
Minor bleeding to life threatening hemorrhage
Local infection to sepsis
113
Long term complications of circumcision
Meatal stenosis (MOST COMMON)
114
How do you prevent meatal stenosis?
Apply petroleum jelly to the glans for up to six months following circumcision
115
Contraindications to circumcision
Hypospadius
Webbed penis
Bleeding diathesis
116
What is the natural history of cryptorchidism?
Most descend spontaneously by 4 mo
117
List consequences of cryptorchidism
Infertility (even after treatment)
Testicular cancer (risk reduced if orchidopexy before age 2)
Inguinal hernia
118
What is a retractile testes?
Descended at birth
| Doesn’t remain in scrotum at age 4-10yrs
119
Management of retractile testes
Monitor Q6-12 months
| If become acquired undescended testes (1/3)-refer to urology
120
BY what should you refer an infant for orchidopexy and when should it be performed?
Refer at 4 months
Ideally repaired 6-12 months
No later than 9-15 months
121
List 2 reasons to perform orchidopexy for UTD
Improved fertility
| Improved examination for cancer
122
DDx for painful scrotal mass in boys
```
Testicular torsion
Torsion of appendix testis
Epididymitis
Trauma: ruptured testis, hematocele
Inguinal hernia (incarcerated)
Mumps orchitis
```
123
Ddx for painless scrotal swelling in boys
```
Hydrocele
Inguinal hernia*
Varicocele*
Spermatocele*
Testicular tumor*
Henoch-Schönleinpurpura*
```
*May be associated with discomfort
124
Ddx of scrotal swelling in newborn
```
Hydrocele
Inguinal hernia (reducible)
Inguinal hernia (incarcerated)*
Testicular torsion*
Scrotal hematoma
Testicular tumor
Meconium peritonitis
Epididymitis*
```
125
Above what age is testicular torsion more common?
>12 years
126
After how many hours of testicular torsion can you have irreversible loss of spermatogenesis?
4-6 hours
127
What is the most common cause of testicular pain 2-10 years of age?
Torsion of appendix testis
| In >12 years-testicular torsion!
128
Physical findings consistent with torsion of appendix testis
Blue dot sign
Tender mass on upper pole
Testicular pain
Scrotal erythema
129
Treatment of torsion of appendix testis
Bed rest and analgesia with NSAIDS x5days
Resoves in 3-10 days
130
What bacteria cause epididymitis?
E.Coli in young boys
Post pubertal – usually STI (gon/chlam)
131
Above what age does varicocele typically present?
Usually after puberty
| >10 years
132
What sided does varicocele typically present?
Left
133
With right sided varicocele, what must you consider?
Abdominal/retroperitoneal mass
134
Why repair varicocele?
Maximize fertility
135
What is the difference between communicating and non-communicating hydroceles?
Non-communicating:
- Disappears by 1yr – no surgery needed
- If older children – can result from inflammatory process (torsion (test/appendix), epididymitis, tumour)
Communicating:
- Persistently patent processus vaginalis
- Hydrocele becomes larger during day and smaller in am
- Long term risk of developing inguinal hernia
- Needs surgery
136
When should hydroceles be repaired?
After 12 months (most should resolve by then)
137
Work up for suspected testicular tumour
1. Scrotal U/S
| 2. Tumour markers (AFP, BHCG)
138
Treatment of testicular tumour
If markers negative-Partial orchidectomy
If markers positive-radical orchiectomy (incl spermatic cord)
139
Difference between acute hydrocele and incarcerated hernia
Incarcerated hernia
kids are probably sicker – signs of abdominal obstruction (vomiting, abdo distention, not stooling, ill)
NOTE: Both can look ill
140
List 2 important physical exam findings in acute scrotal pain
Absence of cremaster reflex
| No relief with prehn maneuver (pain doesn’t subside when elevate scrotum)
141
What is the inheritance pattern of nephrogenic DI?
Most are X-linked (90%), but can be AD, AR
142
List causes of diabetes inspidus
1. Genetic
2. Acquired
- Hypercalcemia
- Hypokalemia
- Drugs (lithium, demeclocycline, foscarnet, clozapine, amphotericin, methicillin, and rifampin)
- Kidney disease (ureteral obstruction, chronic renal failure, polycystic kidney disease, Sjögren syndrome, and sickle cell disease)
143
List associations with hypospadius
```
DSDs
Cryptorchidism (think DSD!)
Inguinal hernias
Anorectal malformations
Congenital heart disease
```
144
When should hypospadius be repaired?
6-12 months of age
145
What is paraphimosis?
Incomplete retraction
| Retracts past coronal sulcus but not over glans
146
What is the definition of micropenis?
In neonates <2 cm
147
List causes of micropenis in the neonate
Hypogonadotropic hypogonadism
- Kallman
- Praderwilli
- Lawrence Moon Biedl
Hypergonadotropic hypogonadism
-Gonadal dysgenesis
GH deficiency
148
What is the definition of priapism?
Persistent penile erection > 4 hrs
149
How does meatal stenosis present?
Usually 3-8 years old
| Forceful fine stream that goes far
150
What is a normal urine protein/creatinine ratio and what is nephrotic range?
Normal:
In 1:1 units
<0.5 in children <2 yo
<0.2 in children ≥2 yo
In mg/mmol:
<25
Nephrotic:
In 1:1 units:
>2
In mg/mmol:
>250
151
What is normal, abnormal and nephrotic range 24 hour protein excretion?
≤4 mg/m2/hr considered normal(or ≤150 mg/24h)
Abnormal is 4-40 mg/m2/hr
Nephrotic range is >40 mg/m2/hr
152
What is the most common cause of persistent proteinuria in children/adolescents?
Orthostatic proteinuria
153
Investigations for orthostatic proteinuria?
3 consecutive first AM urine sample
Diagnostic if dipstick negative/trace for protein
UPr:UC ratio <0.2 for 3 consecutive days
154
Differential diagnosis of fixed proteinuria
Glomerular
- Minimal change nephrotic syndrome
- FSGS
- Mesangial proliferative glomerulonephritis
- Membranous nephropathy
- Diabetic nephropathy
- Obesity-related glomerulopathy
Tubular proteinuria
- ATN
- Reflux nephropathy
- PKD
- Renal dysplasia
- Galactosemia
- Wilson disease
- Cystinosis
155
Workup of fixed proteinuria
- Serum creatinine
- Electrolytes
- Albumin
- Complement (c3, c4, CH50)
- First morning UA, UPr:UCr ratio
156
Causes of false negative proteinuria on dipstick
1. Dilute urine
| 2. Disease where predominant urinary protein is not albumin
157
Causes of false positive proteinuria on dipstick
1. Concentrated urine (SG >1.010)
2. Gross hematuria
3. Exercise, fever
4. Alkaline urine
158
What is the definition of nephrotic range proteinuria?
> 40 mg/m2/h
>50 mg/kg/day
UPr:UCr ratio of >2 or >250 mg/mmol
First morning void urine dipstick 3+/4+
159
List features that distinguish nephritic from nephrotic syndrome
```
Hematuria
Azotemia (↑ BUN)
RBC casts
Oliguria
HTN
```
160
List the causes of nephrotic syndrome from most to least common
MCD > focal segmental glomerular sclerosis (FSGS) >membranoproliferative glomerulonephritis (MPGN)
161
What percentage of nephrotic syndrome is MCD?
85-90% of patients <6 yo
162
List systemic diseases that cause secondary nephrotic syndrome
```
SLE
HSP
Malignancy (lymphoma, leukemia)
Infections (HBV, HCV, HIV, malaria, schistosomiasis, syphilis)
Drugs (NSAIDs, phenytoin)
```
163
What is the typical age of presentation of nephrotic syndrome?
2-6 years
164
What features are in keeping with MCD?
Age 1-10 years of age
Hypertension
Gross hematuria
Marked elevation in serum creatinine
Normal complement levels
No extra-renal symptoms such as malar rash or purpura
165
Ddx of anasarca
```
Protein-losing enteropathy
Hepatic failure
Heart failure
Acute or chronic glomerulonephritis
Protein malnutrition
```
166
Differential for nephritis with low C3
Low C3-MPGN, postinfectious GN, , endocarditis, shunt nephritis
Low C3/C4-Lupus
167
Management of nephrotic syndrome
Salt restriction
Fluid restriction
Daily first AM dipstick and weights
Prednisone 60 mg/m2/day (80 mg max) x 4-6 weeks, then taper
168
In what time frame to most children achieve clinical remission on steroid therapy?
Most within 4 weeks
Short response time (<7 days) is associated with a better prognosis
169
Indications for biopsy in nephrotic syndrome
<1 year, >12 years
HTN
Gross hematuria
Marked elevation in Cr
Abnormal C3/C4
Steroid resistant nephrotic syndrome
Extra-renal symptoms such as malar rash or purpura
170
What percentage of patients with MCD have relapses?
30 % relapse frequently (2+) within 6 months
20% have single relapse
171
What is the definition of clinical remission in nephrotic syndrome?
3 consecutive days of negative urine
172
What is the definition of steroid resistance in nephrotic syndrome?
Fail to respond to steroids within 4-8 weeks
173
What is the definition of steroid dependent nephrotic syndrome?
Relapse when weaning (within 2 weeks of stopping steroids)
174
What is the definition of frequently relapsing nephrotic syndrome?
Respond well but relapse ≥4x in 12-mo period
175
Management of relapsed nephrotic syndrome***
Repeat course high dose prednisone
Fluid and salt restriction
Consider cyclophosphamide
176
List side effects of cyclophosphamide
Neutropenia
Hemorrhagic cystitis
Alopecia
Increased risk of future malignancy
177
What is the most frequent bacteria cause spontaneous bacterial peritonitis?
S pneumo!
| H. flu and E. coli also seen
178
What additional vaccne should children with nephrotic syndrome get and when should they get it?
PPSV-23
| When in remission and off prednisone
179
Should live vaccines be given to children with nephrotic syndrome?
Live virusvaccines should not be given during steroid treatment of >2 mg/kg/day prednisone
180
In a nephrotic syndrome patient with headache, what complications should you think about?
CSVT
| They are prothrombotic!
181
What is the prognosis of steroid resistant nephrotic syndrome?
Poor!
Progressive renal insufficiency
ESRD
Transplant
182
When and how often should patients with T1DM be screening for nephropathy?
Annually starting at age 10 and >5 years after diagnosis
183
What treatment would you consider in T1DM patient with persistent microalbuminuria?
ACEi
184
What are the 4 types of renal tubular acidosis?
Distal (type I) RTA
Proximal (type II) RTA
Combined proximal and distal (type III) RTA
Hyperkalemic (type IV) RTA
185
Describe the pathophysiology of distal RTA
Impaired secretion of H+ from distal tubule-->metabolic acidosis
Compensatory increased K+ secretion-->Hypokalemia
186
Clinical presentation of distal RTA
```
Growth failure
Non-AG metabolic acidosis
Hypokalemia
Urine pH >5.5
Hypercalciuria
Nephrocalcinosis (due to hypercalciuria and hypocitraturia)
```
187
Pathophysiology of proximal RTA
Problem with reabsorption of HCO3 in proximal tubule
188
Laboratory features of Fanconi's proximal RTA
```
Non-AG metabolic acidosis
Hyponatremia
Hypokalemia
Hyperchloremia
LMWH proteinuria (beta 2 microglobulin)
Glucosuria (with normal serum glucose)
Phosphaturia
Aminoaciduria
```
189
List causes of proximal RTA
1. Inherited idiopathic
```
2. Syndromes:
Cystinosis***most common
Lowe syndrome (oculocerebralrenal syndrome)
Galactosemia
Tyrosinemia
Wilsons
Hereditary fructose intolerance
```
3. Drugs
Ifosfamide, cisplatin, gentamicine, valproate
4. Renal disease
Transplant rejection, sjogrens
190
Difference between proximal and distal RTA
Proximal RTA
-Urine pH <5.5 (because distal H+ secretion intact)
-Associated phosphaturia, aminoaciduria, glycosuria,
uricosuria in Fanconis
-Growth failure occurs earlier than dRTA
Distal RTA
-Urine pH >5.5
191
What is cystinosis?
Systemic disease caused by a defect in lysosomal metabolism of cystine
Accumulation of cystine in kidney, liver, eye, and brain
192
Clinical presentation of cystinosis
1. Fanconi proximal RTA
- Polyuria and polydipsia
- FTT
- Rickets
- Dehydration
2. HSM
3. Hypothyroidism
4. Delayed puberty
5. ESRD
193
How do you diagnose cystinosis?
Leukocyte cystine level
| Genetic testing
194
Explain the pathophysiology of Type IV RTA?
Impaired aldosterone production (hypoaldosteronism)
OR
Impaired tubular responsiveness to aldosterone (pseudohypoaldosteronism)
Aldosterone stimulates H+H+/ATPase responsible for H+ secretion (thus ↓aldo = acidosis)
Aldosterone also potent stimulant for K+ secretion (thus ↓aldo = hyperkalemia)
195
Clinical presentation and laboratory features of type IV RTA
Hyperkalemia
Acidosis
Urine pH can be high or low
196
Which of the RTAs is associated with hyperkalemia?
Type IV RTA
197
Which of the RTAs has urine pH <5.5?
Distal RTA
198
Which of the RTAs has a increased urine anion gap ([UNa+ + UK+] −UCl−) ?
Distal RTA
| A positive gap suggests a deficiency of ammonia genesis
199
Which RTA is associated with hypercalciuria?
Distal RTA
200
List long term complications of Fanconi syndrome ***
Rickets
| FTT
201
List 3 symptoms of hypernatremia
Lethargy
Irritability
Thirst
202
List 3 symptoms of hyponatremia
Confusion
Muscle cramps
Lethargy
Seizures
203
Do the number of nephrons change with age?
No
| But functional maturation with tubular growth/elongation continues until 1st decade
204
What is the definition of renal failure as per the pediatric modified rifle (PRIFLE) criteria?
<0.3 ml/kg/h x 24 hours or anuric x 12 hours
205
List pre-renal causes of AKI
Dehydration
Sepsis
Hemorrhage
Hypoalbuminemia Cardiac failure
206
List renal causes of AKI
```
Glomerulonephritis
ATN
AIN
TLS
HUS
```
207
List post-renal causes of AKI
```
PUVs
Bilateral UPJ obstruction
Neurogenic bladder
Tumour compression
Urolithiasis
```
208
List laboratory abnormalities found in AKI
```
Hyponatremia
Metabolic acidosis
Elevated Cr/BUN
Elevated uric acid
Elevated PO4, low Ca
Hyperkalemia
```
209
How do you distinguish between pre-renal and renal AKI with the following tests:
i) SG
ii) Urine osmolality
iii) Urine Na
iv) FeNa
i) SG
- Pre-renal: ↑SG(>1.020)
- Renal: ↓ SG (<1.010)
ii) Urine osmolality
- Pre-renal: ↑ urine osmolality (UOsm> 500 mOsm/kg)
- Renal: ↓ urine osmolality (UOsm< 350 mOsm/kg)
iii) Urine Na
- Pre-renal: ↓ urine Na (UNa< 20 mEq/L)
- Renal: ↑ urine Na (UNa> 40 mEq/L)
iv) FeNa
- Pre-renal: <1% (<2.5% in neonates)
- Renal: > 2% (>10% in neonates)
210
How do you calculate FeNa?
(NaUrine/NaPlasma)/(CrUrine/CrPlasma)
211
What are the principles of management of AKI?
1) Volume optimization
- Fluids if prerenal
- Fluid restriction if renal
2) Treat electrolyte abnormalities
- HyperK
- Hypocalcemia-treat with low phos diet and phosphate binders
- Hyponatremia-fluid restriction
- Metabolic acidosis-only correct if severe
3) HTN
- Salt and water restriction
- Diuretics
- CCBs
4) Nutrition
- restrict Na, K, PO4
212
What are the different types of dialysis and when would you use each?
Hemodialysis
-Stable hemodynamic status
Peritoneal dialysis
-Neonates/infants
CVVH
-Unstable hemodynamic status
213
With which type of dialysis do you need anticoagulation?
HD
214
List indications for dialysis
- Volume overload refractory to diuretics
- Persistent hyperkalemia
- Severe metabolic acidosis unresponsive to medical management
- Neurologic symptoms (altered mental status, seizures)
- Blood urea nitrogen ↑↑ or rapidly rising
- Calcium:phosphorus imbalance, with hypocalcemic tetany
215
What is the definition of CKD?
Renal injury (proteinuria)and/or a GFR<60 mL/min/1.73 m2 for>3 mo
216
List causes of CKD in children
A third a third a third!
1/3: Glomerulonephritis
1/3: Renal dysplasia and other renal malformations
1/3: Obstructive uropathy
Others:
- Prune belly
- FSGS
- ARPKD
- RVT
- Alport syndrome
- Cystinosis
- Hyperoxaluria
217
What parameters are required to calculate eGFR by Schwartz formula?
Height
| Serum creatinine
218
Lab findings in CKD
↑ BUN
↑ K (↓ GFR, acidosis)
Acidosis (impaired HCO3- reabsorption, H+ secretion)
Anemia (↓ EPO, Fe deficiency, ↓ RBC survival)
Hyperlipidemia (↓ plasma lipoprotein lipase)
Hyperglycemia (insulin resistance)
219
Long term complications of CKD
Renal osteodystrophy
FTT (↓ caloric intake, acidosis, anemia, GH resistance)
HTN
Anemia
Pericarditis
Infections
Cardiomyopathy (uremia, HTN, fluid overload)
Bleeding diathesis (platelet dysfunction)
220
Management of CKD
1. Fluid and electrolyte management
2. High calorie diet
3. Short stature: GH
4. Renal osteodystrophy: low phosphate diet, phosphate binders, vitamin D
5. Anemia: EPO
6. Adjust drug doses
221
List 4 reasons for normocytic anemia in CKD
Reduced EPO
Decreased life span of RBC
Anemia of chronic disease
Dilutional with fluid retention
222
What is the definition of microscopic hematuria?
≥5 RBCs per HPF
223
What is can cause red urine without RBCs present?
Heme-positive
- Hemolglobinuria
- Myoglobinuria
Heme-negative
- Drugs
- Dyes – e.g. beets, blackberries, rhubarb, food colouring
- Metabolites – e.g. melanin, methemoglobin, porphyrin, tyrosinosis, urates, homogentisic acid
224
List 10 causes of hematuria
Upper Urinary Tract:
- Glomerular disease
- Pyelonephritis
- ATN
- Vascular Disease → thrombosis, AVMs, aneurysms, hemoglobinopathy
- Hydronephrosis
- PCKD
- Tumour
- Trauma
- Hypercalciuria
Lower Urinary Tract:
- Cystitis
- Urethritis
- Urolithiasis
- Trauma
- Coagulopathy
- Heavy exercise
- Bladder tumour
225
How do you distinguish between glomerular and extraglomerular hematuria?
Glomerular:
- Coca cola
- No clots
- Proteinuria
- Dysmorphic RBCs
- RBC casts
226
List 3 causes of hemorrhagic cystitis
Toxins (cyclophosphamide, penicillins, busulfan)
Virus (adenovirus, influenza A)
Radiation
Amyloidosis
227
If patient has recurrent episodes of gross hematuria, what are 3 possible etiologies?
IgA nephropathy
Alport-think in BOYS
Thin basement membrane disease
228
Workup for isolated microscopic hematuria
- If persists on at ≥3 urinalyses over ≥2-week period:
- Urine culture
- Urine Ca:Cr ratio
- +/- Sickle cell screen
- Renal/bladder US
If these studies are normal:
- Urinalysis of first-degree relatives
- Serum Cr and lytes
229
Workup for suspected glomerulonephritis
```
CBC, diff
Lytes, Cr, BUN
Albumin
Cholesterol
C3/C4
ASOT
ANA
ANCA
Throat/skin culture
```
230
Causes of glomerulonephritis in children
Primary renal disease
- PIGN
- MPGN
- IgA nephropathy
- Alport
- ANCA + glomerulonephritis
Systemic disease
- SLE
- Endocarditis
- Shunt nephritis
- HSP
- ANCA associated disease (Wegener's, microscopic polyangitis)
- Anti-GBM disease
231
How many weeks after initial infection does post-streptococcal GN typically present ?
1-2 weeks after strep pharyngitis
| 3-6 weeks after streppyoderma
232
Over what time period does PSGN resolve?
Proteinuria and HTN usually normalize by 4-6 weeks after onset
Persistent microscopic hematuria can persist for 1-2 years
233
When should C3 normalize in PSGN?
6-8 weeks
234
When should renal biopsy considered in PIGN?
```
ARF
Nephrotic range proteinuria
No evidence of strep infection
Normal complement levels
Lab abnormalities lasting >2 months
```
235
Treatment of PSGN
Pencillin x 10 days
Salt and fluid restriction
Diuretics
CCB for HTN
236
In a patient with PSGN who has persistently low C3 after 8 weeks, what diagnosis should you think of?
MPGN
237
How does IgA nephropathy most commonly present?
Recurrent episodes of hematuria with URTIs
238
What abnormalities on bloodwork would be consistent with IgA nephropathy?
Normal C3
| High IgA
239
How do you treat IgA nephropathy?
Treat HTN
Fish oil decreases rate of disease progression in adults
240
Describe the genetics of Alport syndrome
Mutation in type IV collagen (COL4A5)
| Majority X-linked (also AR, AD)
241
Clinical presentation of Alport syndrome
```
1) Asymptomatic microscopic hematuria
Gross hematuria with URTIs
Progressive proteinuria
2) Bilateral acquired SNHL
3) Eye problems
-Anterior lenticonus=pathognomonic!
```
242
What 3 tests should you order in a patient with suspected Alports?
U/A of 1st degree relatives
Eye exam
Hearing test
243
List 3 risk factors for progression to ESRD in Alports
Gross hematruia in childhood
Nephrotic syndrome
Prominent GBM thickening
244
Describe the genetics of thin basement membrane disease
Sporadic or AD
| Defect in type IV collagen
245
Clinical presentation of thin basement membrane disease
Microscopic hematuria
Gross hematuria with URTIs
Rarely progresses to proteinuria, HTN, renal insufficiency
246
What is the goal of treatment of lupus nephritis?
To induce clinical and serologic remission
Normalization of anti-dsDNA, C3, and C4
247
How often and for how long should you monitor for nephritis in HSP?
Weekly U/A + BP Measurement during active disease
| Then monthly x 6 months
248
What are the two defining clinical features of Goodpastures?
Pulmonary hemorrhage
| Glomerulonephritis
249
How do you diagnose Goodpastures?
Anti-GBM antibodies
250
Triad of HUS
1) Microangiopathic hemolytic anemia
2) Thrombocytopenia
3) Renal insufficiency
251
List 3 infectious causes of HUS
1. Verotoxin-producing E. Coli
2. Shigella
3. Neuraminidase producing S. pneumonia
252
List 3 conditions other than HUS that have microangiopathic hemolytic anemia and thrombocytopenia
SLE
Malignant HTN
Bilateral renal vein thrombosis
253
List 3 non-infectious causes of HUS
1. Genetic-inherited deficiencies of vWF, complement factors
- THINK ABOUT THIS IF HUS WITHOUT diarrheal prodrome
2. Drugs (e.g. cyclosporine)
3. Systemic diseases (SLE, malignant HTN)
254
List the causes of nephrolithiasis in children
1. Hypercalciuria
2. Hyperoxaluria
3. Hypocitraturia
```
Others (less common):
Hyperuricosuria
Cystinuria
Struvite stones
Indinavir
```
255
What % of renal stones are visible on AXR?
90% are radioopaque
256
List 3 types of stones that are radiolucent
Cystine
Xanthine
Uric acid stones
257
List the components of a stone workup
Serum:
- Calcium
- Phosphate
- Uric Acid
- Lytes and VBG
- Creatinine
- AlkPhos
Spot Urine:
- Urinalysis
- Culture
- Ca:Cr ratio
- Nitroprusside screen
24h Urine
- Cr clearance
- Calcium
- Phosphate
- Oxalate
- Citrate
- Uric Acid
- Dibasic amino acids (if cysteine spot test positive)
258
What are the two most common stone types in North America?
Calcium oxalate
| Calcium phosphate
259
Treatment of calcium renal stones
```
Hydration (3L/1.73m2)
Stop extra vit D
Avoid excess Ca
Thiazide diuretics (if persistent nephrocalcinosis or recurrent stones)
Potassium citrate
```
260
Describe the pathophysiology of struvite stones
Associated with UTIs caused by urea-splitting organisms
Leads to urinary to urinary alkalinization and excessive ammonia production
Leads to precipitation of magnesium ammonium phosphate (struvite) and calcium phosphate
261
List 3 bacteria associated with struvite stones
Urea-splitting organisms
- Proteus
- Klebsiella
- E. Coli
- Pseudomonas
262
List 3 conditions associated with uric acid stones
Inborn error of purine metabolism
Lesch-Nyhan
G6PD
Short gut
263
List 2 conditions associated with struvite stones
Neurogenic bladder
| Reconstructed bladder
264
Treatment of uric acid stones
Allopurinol
| Urinary alkalinization
265
Describe the pathophysiology of cystinuria
Rare AR disorder of renal tubular epithelial cells
Prevents absorption of the 4 dibasic amino acids (cystine, ornithine, arginine, lysine)
266
Treatment of cystine stones
Urinary alkalinization
| D-Penicilliamine
267
List 5 causes of nephrocalcinosis
```
Lasix
Distal RTA
Hyperparathyroidism
Hypophosphatemic rickets
Medullary sponge kidney
Hyperoxaluria
Hyperuricosuria
```
268
Most common cause of microscopic hematuria
Idiopathic — 36%
Benign familial hematuria
Hypercalciuria — 22%
IgA nephropathy —16%
Post-streptococcal glomerulonephritis — 7%
Other glomerulopathies including thin basement membrane disease — 2%
Congenital anomalies (eg, UPJ obstruction or renal dysplasia) — 2%
Sickle cell trait — 1%
269
List 5 findings on ultrasound that might indicate reflux and need for VCUG
```
Pelviectasis 5mm or greater
Size discrepancy kidneys
Significant hydroureter
Thick walled trabeculated bladder
Renal cysts
```
270
What percentage of children with nephrotic syndrome respond to steroids?
80%
271
Differential for nephritis with normal C3
Kidney only:
IgA nephropathy
Anti-GBM disease
Alports
Systemic:
Good pastures
ANCA positive GN
272
List 3 stone promoters
```
Calciuria
Oxaluria
Urate
Cystine
Urinary stasis
Infection
```
273
List 3 stone inhibitors
Citrate
Phosphate
Magnesium
High urine flow
274
What is significant antenatal pelviectasis?
Abnormal if >10mm at >=32 weeks GA
275
If baby has >10mm antenatal pelviectasis at >32 weeks, what should be done postnatally?
Trimethoprim prophylaxis
| Ultrasound 3-10 days
276
What would you do with the following postnatal ultrasound results:
RPD<1 cm
RPD 1-1.2cm
RPD >1.2 cm
**NOTE: will not be tested-this is a sickkids guideline
RPD<1 cm
- Stop TMP
- No more U/S
RPD 1-1.2cm
- Continue TMP
- Repeat US at 3 mo
RPD >1.2cm
Continue TMP
VCUG
277
What is nuclear scan with lasix washout used for?
Assess for:
1) Obstruction
2) Differential kidney function
278
List 3 steps in management of solitary kidney
1. Serial US to ensure proper growth
2. Avoid ccontact sports, sky diving
3. Yearly U/A and BP
279
What does the creatinine of a newborn baby represent?
Mom's creatinine
