Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FRACP Exam > Renal > Flashcards

Renal Flashcards

1
Q

Accelerated renal failure

A

factors increasing progression of renal failure:

1. hyperlipidaemia: CVD and renal dysfunction

2. metabolic acidosis: increased local ammonia

3. phosphate retention: CaPO4 precipitation

4. Proteinuria: likely toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Acid/Base

A

Henderson-Hasselbach:

pH= 6.1 + log ([HCO3]/(0.235 x [PaCO2]))

pH equation:

pH= -log [H+]

pKa

  • pH at which 50% acid molecules are undissociated and 50% associated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Acute Kidney Injury

A

definition: inability to excrete solute load

diagnosis: GFR< 100ml/min/173m2, increase Cr >1.5X baseline, UO<0.5ml/kg/hr

  • increased Cr/urea/K/PO4

- decreased Na/Ca/VitD/HCO3

  • AKI: large swollen kidneys versus CKI: small shrunken kidneys

clinical:

  • water causing oedema
  • Na causing HTN
  • K causing arrhythmias
  • H causing metabolic acidosis
  • urea causing nausea/vomiting/encephalopathy
  • phosphate causing decreased calcium

management

  • electrolyte mx, fluid management, treat infection, remove nephrotoxins, monitor weight/BP

prognosis: complete loss of function >4weeks, ongoing unlikely to recover after 2-3 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

ADH/vasopressin

A

synthesised in hypothalamus and released from posterior pituitary

control of secretion:

  • increased osmolality: stimulation osmoreceptors in anterior hypothalamus AND
  • decrease fluid vol: tension/stretch of volume receptors in vena cavae/great pulm veins/carotid sinus/AA

actions:

  • acts on V2 receptors which are G protein coupled
  • phosphorylate ATP to cAMP and cause insertion of aquaporin 2 channels in DT/CD

causes excess ADH:

- pituitary ADH excess: hypoadrenalism/stress, drugs (barbiturates/vincristine), lung disease, IC disease, systemic disease (acute int prophyria)

- increased ADH sensitivity: carbamazepine

- ectopic ADH secretion: bronchogenic carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ADPKD

A

incidence: 1/1000

genetics: chromosome 16, polycystin 1/2 maintain renal cell tubular differentiation/proliferation

  • 10% new mutation

clinical: most paediatric patients asymptomatic until adulthood

  • renal: large bilat hyperechoic kidneys due to cysts
  • symptoms in adulthood: haematuria, HTN, proteinuria, infection cysts, abdo/back pain, renal insufficiency
  • cardiac valve, hepatic, pancreatic, colonic diverticular, splenic cysts, berry aneurysm 10%

diagnosis (Ravine’s criteria):

  • postive family history and renal US
  • genetic testing if US indeterminant

prognosis: normal renal function until 40’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Aldosterone

A

definition: C21 mineralocorticoid hormone secreted by zona glomerulosa of adrenal cortex

actions: Na/Cl reabsorption and K/H excretion in distal tubules/collecting ducts

secretion: via RAAS

  • cAMP mediated (indep ACTH) or ACTH stimulation

increased secretion

  • 10% decrease plasma Na or 10% increase plasma K
  • upright postion
  • loss ECF
  • surgery/anxiety
  • hyperaldosteronism
  • RAS

decreased secretion:

  • increased Na, adrenalectomy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Alport syndrome

A

type: diffuse GBM

incidence: AR 15%, AD 5%, X linked 85% mutation of type IV collagen

  • associated family history

pathogenesis: GBM/tubular membrane thinning/thickening/splitting with foam cells (lipid containing tubular cells), progressive, may also affect ears/eyes

clinical: microscopic haematuria with episodes of synpharyngitic macrohaematuria +/- proteinuria

  • SNHL deafness (NOT congenital)
  • anterior lenticonus, corneal erosions, macular flecks

diagnosis: genetic studies, biopsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Anion Gap

A

Anion gap= [Na + K] - [Cl + HCO3]

Normal anion gap= 10-16 mmol/l

increased AG: renal failure, diabetic/alcoholic ketoacidosis, lactic acidosis, ingestion salicylate/methanol/ethylene glycol/paraldehyde

decreased anion gap: increased unmeasured cation eg. potassium/Mg/calcium, decreased unmeasure anion eg. hypoalbuminaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ANP

A

ANP: secreted from atrial tissues with fluid overload and causes natriuresis/vasodilation

renal effect:

  • dilates afferent/constricts efferent glomerular arteriole
  • relaxes mesangial cells
  • increased excretion Na/water
  • decreased reaborption in DCT/CD
  • inhibition of renin secretion
  • reduction in aldosterone secretion in zona glomerulus

vascular effect:

  • relaxation vascular SM
  • inhibition of catecholamines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Antenatal hydronephrosis

A

outcome:

  • hydronephrosis w/o ureteric dilation not concerning: transient, pelvic ureteric obstruction, VUR
  • hydronephrosis with ureteric dilation needs Ix

risk factors:

  • bilateral hydro APD >10mm, unilateral APD > 15mm
  • single kidney, duplex system, ureteric dilation, ureterocoele, oligohydramnios

management: AB at birth, US day 4-7

  • if less dilation then repeat in 1 month
  • if severe admit

investigations: MAG3 < 6weeks, DTPA > 6 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ARPKD

(aka infantile PKD)

A

incidence: 1/10,000

genetics: carriers 1:70, chromosome 6, PKHD1 gene for protein fibrocystin/polyductin

pathogenesis: renal cystic disease in utero with dilation of CD

antenatal dx: antenatal scan: large echogenic kidneys with microcysts <3mm

clinical:

  • neonatal: enlarged kidneys, oligohydramnios, pulmonary insufficiency
  • renal: hyponatraemia, poor [] ability, metabolic acidosis, recurrent UTIs, proteinuria, glycosuria, hyperphosp, magnesiuria, HTN, renal failure
  • liver: congenital hep fibrosis, dilation intrahep/main bile ducts, degree varies, develop hepatomegally, portal HTN
  • resp: lung dysplasia, Potter syndrome

prognosis: survive 1st month then 80% chance to 15yrs

diagnosis: renal imaging +1 (hep fibrosis/pathology, absence cysts both parents/ARPKD in siblings/consanguinity)

  • renal US: large echogenic kidneys with poor corticomed differentiation
  • liver: increased echogenicity, dilation of intrahep ducts

management: no disease recurrence in transplant

complications: UTI, bacterial cholangitis, portal HTN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Acetozolamide

A

mechanism: inhibits carbonic anhydrase

effect: NaCl and NaHCO3 loss but NET diuresis

  • LOH then absorbs it
  • diuretic action attenuated by met acidosis from loss of HCO3

indication: diuretic for oedematous patients with met alkalosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Bardet-Biedel

A

incidence: 1:140,000

genetic: AR digenetic, 12 genes localised to primary cilia/basal bodies

clinical: polydactyly, truncal obesity, retinal dystrophy, hypogonadism, renal involvement 70%, ID, anosmia, situs inversus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Bartter/Gitelman syndrome

-tubular hypomagnesemia/hypokalaemia-

A

incidence: onset infancy, Gitelman 1/40,000, Bartter 1/1,000,000

genetics: AR

pathophysiology: tubular defect in NaCl transport

Bartter: acts as loop diuretic and prevents NaCl reabsorption in ascending LOH

Gitelman: acts as Thiazide

  • unable to concentrate urine
  • hypocalciuria
  • less severe

clinical: severe, growth/mental retardation, polyuria, polydipsia

diagnosis: hypokalaemic met alkalosis, low serum Na/Mg, high urine Cl

  • H+ ions lost to reabsorb K+
  • elevated renin/aldosterone

treatment: KCl, NSAIDs, spironolactone, ACEi, fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Benign familial haematuria

aka. thin basement membrane disease

A

type: diffuse

incidence: family hx haematuria, sporadic/AD mutations type IV collagen

pathogenesis: thinning GBM

clinical: microscopic haematuria with episodes of gross haematuria

diagnosis: normal complement

prognosis: benign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Buffers

A

children make 2-3mEq/kg of acid

buffers:

  • HCO3 in ECF

HCO3 + H+ ⇔ H2CO3 ⇔ dissolved CO2 + H2O

  • H renally excreted and HCO3 reabsorbed

base excess:

  • normal -2 to 2
  • reflects the excess or deficit of base
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Hypertension

A

classification:

normal: <90th centile

preHTN: 90-95th centile

stage I: 95-99th centile +5mmHg

stage II: >99th centile +5mmHg

types:

primary

secondary (30%): more common in infants

  • renal (60-80%): parenchymal, vascular, obstruction
  • cardiac
  • endocrine: CAH, cushing’s, phaeo, thyroid
  • central
  • OSA
  • drugs: steroids, OCP, thyroxine
  • tumours: neuroblastoma

diagnosis: BMI, 4 limb BPs and pulses

investigations: UEC, LFT, FBC, urine (Pr:Cr), renin, aldosterone, renal dopplers, MAG3, angiography, TTE, CXR, TFTs, cortisol, HbA1c

treatment: nifedipine, ACEi, prazosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Calcium calculi

A

hypercalciuria

incidence: commonest cause (60-90%)

increased urine Ca by:

  • increased dietary Na
  • increased dietary Ca, Vit C, Vit D
  • decreased Ca (increases oxalate absorption as usually Ca bound)
  • immobilisation
  • oliguria
  • drugs: lasix, topiramate, steroids
  • genetics: Bartters, Bents, Cl channel defect

clinical: calculi, nephrocalcinosis, decreased BMD

treatment: fluids, decreased dietary Na, increase dietary K, calcium chelation, thiazides (reabsorb Ca in tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

causes of haematuria

A

‘SHIRT’

Stones

Haematologic abnormalities

  • AVM, coagulopathy, sickle cell

Infection/Iatrogenic/Idiopathic/Immunologic

  • BFH, haemorrhagic cystitis, collagen vasc disease, epididimytis, exercise, UTI, vasculitis

Renal abnormalities: anatomic, Alport’s, nephritis, renal vein thrombosis

Tumour/Trauma: hypercalcaemia, foreign body, perineal irritation/trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Chronic kidney disease

A

definition: GFR< 60 for >3months or with evidence of structural damage

stages:

stage 1: normal GFR >90,

stage 2: GFR 60-69

stage 3: GFP 30-59

stage 4: GFR 15-39

stage 5: GFR<15

OR <2yrs: 1-2 SD from mean is moderate, >2SD from mean is severe

cause: congenital abnormalities (60%), cystic (ARPKD, ADPKD), GN (17%)

progress: once diagnoses, gradual progression and decline

management: SLOW progression, maintain growth/development, preserve vasculature

treatment: dyslipidaemia (statins >10yrs, exercise), proteinuria (ACEi), hyperphosphataemia (low Ph diet, Ph binders), Na retention (low Na diet), hyperkalaemia (low K diet, frusemide), met acidosis (NaBicarb), osteodystrophy (Ph binders, vit D), anaemia (EPO, Fe)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

CMV in immunosuppressed

A

various clinical syndromes in immunocompromised patients with multiple organ system involvement

clinical:

  • most important manifestations: pneumonitis, GI disease, and retinitis
  • GI disease: esophagitis, gastritis, gastroenteritis, pyloric obstruction, hepatitis, pancreatitis, colitis, and cholecystitis
  • nausea, vomiting, dysphagia, epigastric pain, icterus, and watery diarrhea.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Complement mediated HUS

A

incidence: rare, 50% non Shiga HUS

pathophysiology: trigger event with gene mutation leads to uninhibited activation of the alternative pathway with formation MAC

  • results in renal endothelial damage and activation of coag cascade and thrombotic microangiopathy

clinical: microangiopathic haem anaemia, thrombocytopaenia, AKI

  • assoc family hx, HTN, trigger

diagnosis: screening for mutations not widely available, consider in family hx or previous episodes HUS

treatment: supportive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Congenital nephrotic syndrome

A

onset: at birth or within 3 months

clinical: oedema, FTT, infections, hypothyroidism, thrombosis

  • most progress to ESKD

causes:

primary: congenital, diffuse mesangial sclerosis, MCNS, FSGS, membranous

  • mutations in 4 genes: NPHS1/2, WT1, LAMB 2 (GBM components)
  • Denys-Drash syndrome: WT1 mutation with abnormal podocytes
  • Pierson syndrome: LAMB2 gene for B2 laminin

secondary: infection, drugs, SLE, syndromes, HUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cystine calculi

A

incidence: 1-5% stones

onset: in childhood

mechanism: defective reabsorption of dibasic AAs in tubule causing cystine precipitation in hexagonal crystals

diagnosis: urine microscopy, RADIOLUCENT

treatment: fluids, alkalinise urine, decreased Na, penicillamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Cystinosis

A

definition: AR lysosomal storage disorder, most common cause of Fanconi’s

clinical: FTT, rickets, cystine deposits (cornea, renal, pancreas, thyroid, cardiac, muscle)

  • normal intelligence

treatment: very treatable with cysteamine caps and eye drops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Dent’s disease

A

definition: XLR of renal tubules due to defect Cl Channel CLC-5

clinical: nephrocalcinosis, hypercalciuria, calculi, renal failure, renal rickets, proteinuria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Denys Drash syndrome

A

genetics: point mutation WT1 gene chromosome 1

clinical: (triad)

  1. progressive renal disease (early nephrotic sx then mesangial sclerosis)
  2. undifferentiated genitals
  3. Wilm’s tumour (90%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Diagnosis SIADH

A

hypo-osmotic overhydration

diagnosis:

  • hyponatraemia/low plasma osm
  • urine Na output inappropriately high >50mmol/day
  • urine osm inappropriately high relative to serum: 350-400mosmol
  • no evidence hypovolaemia
  • increasing plasma osm in response to restriction of water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Dialysis

A

indications: acidosis, hyperkalaemia, uraemia >80, fluid overload

effectiveness:

  • conventional HD/PD: 15% normal function
  • short daily HD: 25% normal function
  • home nocturnal HD: 50% normal function

**peritoneal dialysis preferred in children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Differential Glomerular Disease

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Diffuse cystic dysplasia

A

genetics: sporadic or associated syndrome

pathology: small cysts in cortex, sometimes duplex kidney/GUT abnormalities

associations: tuberous sclerosis, Zellweger, trisomy 13

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Distal RTA

(type 1)

A

defect: inability to excrete acid

  1. failure NH3 concentration in medullary interstitium
  2. failure of distal H+ secretion

causes: genetic, drugs, carbonic anhydrase def (OP), AI, obstructive uropathy

complications:

  • calculi: no citrate in urine and Ca/PO4 insoluble at high pH
  • assoc deafness

diagnosis: alkaline urine (low K+, high NH3)

treatment: correct acidosis, K citrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Distal tubule/collecting duct

A

reabsorption: 5% Na and 3% bicarb

  • variable water reabsorption in collecting ducts depending on ADH

tubular absorption: Na absorbed via channel coupled to K excretion

tubular secretion: ammonium, H+, K+ under influence of aldosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

DMSA scan

  • scarring
A

Dimercaptosuccinic acid (radio-labelled)

1) Scarring: sticks to PT and outlines cortical mass to detect cortical scarring
2) Differential function of each kidney= time taken to uptake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Electrolyte dysfunction

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Endothelins

A

potent vasocontricting peptides produce various tissues

types: endothelins 1- 2- 3- interactive with 2 G protein receptors type A and B

  • increased iCa and stimulate protein kinase C

function: modulate vasomotor tone, cell proliferation, hormone production

endothelin 1:

  • produced in endothelial and vascular smooth muscle cells
  • most potent vasoconstrictor
  • role in heart failure, renal failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Enuresis

A

definition: repetitive voiding or urine into clothes/bed

  • at least twice/week for 3 months in child >4yrs

epidemiology: 5yrs (7% boys, 3% girls), 18yrs (1% men, 1% girls)

risk factors: low SE, large families, institutionalised children, family hx

subtypes:

diurnal

nocturnal can be:

  • monosymptomatic: no assoc daytime sx
  • nonmonosymptomatic (more): 1 subtle daytime sx

- primary enuresis (85%): never dry

- secondary enuresis: resumption post dry 6 month

voiding

  • bladder vol= (age x 30) + 30
  • frequency: 3-8 x

resolution: 15% spontaneous cure rate annually

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Enuresis

causes and treatment

A

causes

diurnal/nocturnal: renal (CKD, UTI), endo (DM, DI), GI (constipation), sleep (OSA), neuro (SC disorder/GDD)

nocturnal: primary rousability, genetic component, nocturnal polyuria (low ADH night), psychological

diurnal: MOST overactive bladder, voiding postponement, bladder dys, giggle incontinence, vaginal voiding

treatment:

1. Conservative: education, charting, void before bed

2. Alarm (best treatment): 75-95% success at 3 months (NOT <7 yrs)

3. Medications: DDAVP (high relapse when ceased), imipramine (<50% respond)

diurnal: + oxybutinin, tolteridone

  • refer to urology IF: diurnal, abnormal voiding, UTIs, genitals abnormal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Fanconi’s syndrome

A

definition: generalised proximal tubular dysfunction

causes:

  • genetic: cystinosis, Lowe’s, Dent’s disease, galactossaemia, tyrosinaemia, Wilson’s, heredity fructose intolerance
  • acquired: interstitial nephritis, drugs, heavy metals, frusemide, aminoglycosides, cyclo, tacro, amphotericin, ifosfamide

clinical: vomiting, FTT

diagnosis: urine osm <300, glycosuria, phosphaturia, low PO4, amnioaciduria, tubular proteinuria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Functional scans (MAG3 and DTPA)

A

DTPA: isotope purely excreted like creatinine

MAG 3: 20% isotope secreted at the tubules so always dye even if GFR is 0 (better images)

functional scans show:

  1. contribution of each kidney to overall function
  2. obstruction

process:

  • baseline image then dye injected
  • 2nd image at 2-3 mins to assess uptake/% contribution to function of each kidney
  • frusemide given at peak uptake (20-30 mins)
  • measure for washout time: if <15 mins then no obstruction, if >20 mins obstruction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Gitelman syndrome

A

site: distal tubule

age: teens/adults

defect: NaCl in distal collecting duct

  • causes thiazide like effect
  • hypovolaemia/hypotension, high renin/aldosterone, K/Mg wasting, low urine Ca, high urine Cl

clinical: low growth, salt craving, muscle cramps, tetany, hypotension, fatigue, polyuria

diagnosis: hypokalaemic met alkalosis, high urine Cl, low serum Mg, high serum Ca

  • NORMAL urine concentrating capacity

treatment: KCl, Mg, spironolactone, fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Glomerular Filtration

A

GFR= no. nephrons X single nephron GFR

Normal GFR= 100ml/min/m2

Newborn GFR= 15ml/min/m2

renal blood flow (20-30% CO): renal perfusion pressure (BP)/ renal vascular resistance

filtration fraction: GFR/RBF

filtration of plasma: 20X/hour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Glomerular structure

A

mesangial cells: connective tissue that controls pressure in glomerula

filtration (3 layers): endothelium, GBM, podocytes with foot processes

macula densa: epithelial cells in DCT, sense change in BP

juxtaglomerular apparatus: sits next to afferent arteriole and responds to signals from macular densa to secrete renin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Glomerulocystic kidney disease

A

incidence: uncommon

clinical: present in neonatal period

  • 10% liver fibrosis

pathology: large echogenic kidneys, microscopic glomerular cysts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Glomerulonephritis

A

pathophysiology: preformed immune complexes or insitu immune complex formation with secondary injury via complement cascade and coagulation

clinical:

  • haematuria +/- proteinuria
  • AKI with oliguria, hyperkalaemia
  • nephrotic syndrome with 2 types: SLE and membranous

diagnosis:

  • GN screen: C3/C4, ANA, dsDNA, ANCA, antiGBM, ASOT/DNAse B, urine
  • granular and red blood cell casts
  • renal biopsy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Glomerulonephritis

A

definiition: symptoms haematuria, proteinuria, oedema, HTN caused by glomerular injury accompanied by inflammation

pathogenesis: immunologic response to several biological processes

  • may be isolated to the kidney or part of a systemic disorder

- primary disease: humoral response to inciting agent with Ig deposition and complement activation

- secondary disease: primary disease activates complement, coagulation and leukocyte systems that cause disease

presentations:

- acute GN: PSGN, HSP, post bacterial endocarditis

- RPGN: anti-GBM, IgA nephropathy, MPGN, SLE, PSGN, HSP, granulomatosis with polyangitis

- recurrent macroscopic haematuria: IgA nephropathy, Alport syndrome

- chronic GN: MPGN, IgA , antiGBM, SLE, granulomatosis

evaluation: light microscopy, immunofluorescence, electron microscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Goodpasture’s disease

A

type: focal

cause: unknown

pathogenesis: anti-GBM to type IV collage of GBM of lung/glomeruli

clinical: rare in childhood, smokers

diagnosis:

  • antiGBM, normal C3
  • biopsy: linear deposition of anti-GBM IgG Ab

treatment: IV steroid, immunosuppressants, IvIg

  • ALL progress to ESKD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Haematuria

A

definition: >500 RBC/ml

incidence: asymptomatic haematuria in 0.5-2% children

RBC casts/dysmorphic: glomerular pathology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Haemodialysis

A

advantage: rapid correction of fluid overload/electrolyte abnormalities, removes burden from carer

disadvantage: big central venous access (CVC/AV fistula), blood in fillter at all times

mechanism (counter-current)

  • dialysate flows opposite direction to blood through cylinders maintain concentration gradient for exchange of solutes
  • fluid removes by hydrostatis pressure of dialysate fluid

complications: hypotension, renal ischaemia, dysequilibrium syndrome (rapid shifts in urea)

contraindications: haem instability, severe coagulopathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Haemolytic Uraemic Syndrome

A

definition: simultaneous microangiopathic haemolytic anaemia, thrombocytopaenia and AKI

pathophysiology: post gastroenteritis then thrombotic microangiopathy causing fibrin/clot in glomerulus and secondary poor filtration/acute renal failure

clinical: renal failure, hepatomegally, CNS (30%) with irritability, pancreatitis (<10%), myocarditis

  • similar to TTP but more renal/neurological symptoms

diagnosis: anaemia, thrombocytopaenia, Coomb’s negative, fragments/schistocytes on film, raised transaminases

subtypes:

primary causes

  • complement gene mutations
  • antibodies to complement factor H

secondary causes

  • infection: shiga toxin producing ecoli (STEC), strep pneumo, HIV
  • inborn error of cobalamin C metabolism
  • drug toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

HSP Nephritis

A

type: focal IgA (similar to IgA vasculitis)

pathogenesis: small vessel vasculitis with IgA deposits in glomeruli

clinical:

  • purpuric rash, abdo pain, arthritis
  • 50% renal often weeks to months post initial symptoms

diagnosis:

  • normal C3

treatment:

  • no evidence for steroids in HSP to prevent renal injury
  • steroids, immunosuppressants

prognosis: worse if acute renal involvement at diagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Hyperkalaemia

A

7% filtered potassium is excreted with almost all reabsorbed PCT

regulation K excretion: aldosterone, serum [K]

causes:

pseudohyperkalaemia: haemolysis

redistribution: met acidosis, DKA, familial hyperkalaemic periodic paralysis

true hyperkalaemia

  • low GFR: poor clearance, increased K load, decreased K excretion
  • normal GFR/low aldosterone: low renin (diabetic nephropathy, interstitial nephritis, obstructive uropathy), normal renin (adrenal insuff, drugs ACEi/ARB)
  • normal GFR/high aldosterone: pseudohypoaldosteronism, drugs (K sparing), obstructive uropathy/sickle cell nephropathy, post renal transplant

clinical: arrhythmia if >8.5mmol/L

diagnosis:

  • ECG: small p waves, prolonged PR, wide QRS, peaked t waves

management:

acute: cardiac monitor, ECG, calcium gluconate, salbutamol, insulin/dextrose, frusemide, resonium, dialysis

chronic: low K diet, loop diuretic

53
Q

hypoaldosteronism RTA

type 4

A

mechanism:

  1. aldosterone deficiency
    - eg. CAH, pseudoaldosteronism with UTI
  2. tubular aldosterone resistance
  3. drugs that impair aldosterone
    - eg. heparing, NSAIDs, calcineurin inhibitors, trimethroprim
  4. interstitial nephritis

diagnosis: decreased Na, increased K acidic urine, increased renin, low aldosterone

treatment: mineralocorticoids

54
Q

IgA Glomerulonephritis

A

type: focal

incidence: sporadic (family hx uncommon), linked 6q22-23, assoc HSP

pathophysiology: mesangial deposits IgA complexes (glomerulus not involved)

clinical variable presentations:

  • synpharingitic episodes of haematuria
  • persistent micro haematuria
  • acute nephritis
  • nephrotic syndrome

diagnosis: biopsy (IgA levels not helpful)

treatment: BP control, +/- steroids, immunosuppressants

prognosis: often benign, 20% CKD

55
Q

Imaging UTIs

A
56
Q

Interstitial renal disease

A

acute interstitial nephritis

mechanism: inflammatory infiltrate in kidney interstitium with immune mediated inflammation of the tubules

cause:

  • drugs: NSAIDs, antibiotics
  • infections
  • TINU: tubulointerstitial nephritis and uveitis syndrome
  • systemic disease: SLE, sarcoidosis

clinical: usually 1-2 weeks post exposure

  • nausea, vomiting, abdo pain

diagnosis: non oliguric, no proteinuria, increased Cr

  • biopsy if severe or systemic cause suspected

management: removal of offending agent, supportive, ?steroids

57
Q

Intrinsic Renal AKI

A

causes:

  • vascular disease: HUS, thromboses
  • glomerular disease: GN
  • CAKUT (congenital): cystic
  • tubular disease
  • interstitial disease
58
Q

Joubert syndrome

A

genetic: AR, 3 mutations, also NHPH gene defect

clinical:

  • renal: variable cystic
  • cerebellum: vermal aplasia
  • eye: coloboma, retinitis pigmentosa
  • congenital hypotonia
  • ocular-motor apraxia
59
Q

Kidney anatomy

A
60
Q

Liddle syndrome

aka. Pseudohyperaldosteronism

A

genetics: rare AD

pathogenesis: increased activity luminal membrane sodium channels

diagnosis: low aldosterone/renin

clinical: present at young age with HTN, hypokalaemia, metabolic alkalosis

treatment: amiloride

61
Q

Loop diuretic

Frusemide

A

mechanism: acts on thick ascending limb to decrease Na reabsorption via Na/Cl/2K transporter

effect: excretion 25% filtered Na and increases Ca excretion

side effects:

  • high glucose/TG/cholesterol
  • low uric acid/Ca/Cl/K/Mg/Na
  • metabolic acidosis
62
Q

Loop of Henle Function

A

Counter current multiplier system establishes osmotic gradient in interstial tissue from cortex to medulla

  • descending tubule: impermeable solute, loses water, increasing concentration
  • ascending tubule: impermeable to water, loses solutes, more dilute

Na absorption: Na/Cl/2K co transport

  • inhibited by frusemide
63
Q

Lowe syndrome

A

definition: oculorenal syndrome

genetics: OCRL1 gene defect

clinical: presents like Dent’s disease

- renal: PT failure (type 2 RTA), nephrocalcinosis, renal calculi, renal osteodystrophy

  • congenital cataracts
  • mental retardation
64
Q

Mannitol

A

mechanism: non reabsorbable sugar alcohol

  • acts as osmotic diuretic inhibiting sodium and water reabsorption in PT and LOH
65
Q

MCUG

micturating cystourethrogram

A

investigation: obstruction, VUR

process: catheterise, fill bladder with radiolabelled material, scan with voiding

diagnosis: shows bladder wall thickening/trabeculation

VUR

grade 1: reflux into ureter

grade 2: into collecting system w/o dilation

grade 3: into collecting system with mild dilation

grade 4: moderate dilation but still impression of calyces

grade 5: severe dilation

  • note: prophylactic AB> grade 2
66
Q

Meckel-Gruber syndrome

A

incidence: AR, rare

clinical: neurosurgical and renal problems

67
Q

Medullary cystic disease

aka. Juvenille nephonopthisis

(AD tubulointerstitial kidney disease)

A

genetic: AD rare

clinical:

  • progressive decline in kidney function from adolescence
  • polyuria, enuresis, anorexia, pallor
  • ESKD in adulthood (or earlier if juvenille form)

pathophysiology: tubulointerstitial kidney disease

biopsy: cortico-medullary cystic changes

US: normal/small kidneys

diagnosis: elevated uric acid/creatinine

68
Q

Membranoproliferative GN

A

incidence: adolesence/teens

type of GN with:

  • characteristic light microscopy changes: mesangial hypercellularity, endocapillary proliferation and double-contour glomerular capillary walls
  • histological changes: thickened GBM, increased mesangial/endocap cellularity

immune-complex mediated:

most common with chronic antigenemia/circulating immune complexes

  • associated chronic infections (eg HBV, HCV, fungus, parasites), AI diseases (eg SLE, Sjorgens, RA), monoclonal gammopathies (eg multiple myeloma)

complement-mediated MPGN:

less common from dysregulation and persistence of alternative complement p/w

  • deposition of complement along capillaries in mesangium

classification with electron microscopy

MPGN I: immune deposits mesangium/subendo space

MPGN II (worst prognosis): dense deposits along GBM, tubules, bowman’s capsule

MPGN III: type I with subepithelial deposits

diagnosis: low C3, normal C4

treatment: prednisone, immunomodulators, Ig, recurs post transplant

prognosis: ESKD 50% in 10 yrs

69
Q

Membranous Glomerulonephritis

A

type: focal non proliferative

pathogenesis: subepithelial immune deposits (not cellular)

  • secondary to SLE, HepB, tumours

clinical: nephrotic syndrome

  • haematuria common

diagnosis:

  • normal C3
  • biopsy: thick BM, spikes on silver stain

treatment: steroids if nephrotic, ACEi if non nephrotic

70
Q

Metabolic acidosis

Increased AG

A

Increased anion gap‘MUDPILES’

Methanol

Uremia

Diabetic Ketoacidosis

Paracetamol

Iron, Inhalants (CO, cyanide, toluene), Isoniazid, Ibuprofen

Lactic acidosis

Ethylene glycol, ethanol ketoacidosis

Salicylates, starvation ketoacidosis, sympathomimetics

71
Q

Metabolic acidosis

A

renal compensation

  • HCO3 reabsorption: 85% in PCT
  • regeneraton of HCO3 by excretion of NH4 in DCT
  • NH3 + H+ and NH4 excreted
72
Q

Metabolic acidosis

Normal AG

A

Normal AG acidosis ‘USED CARP’

Ureteric diversion

Small bowel fistula

Excessive Cl

DKA resolving

Carbonic anhydrase inhibitors

Addisons

Renal tubular acidosis (Types 1, 2 & 4)

Pancreatic fistula

73
Q

Metabolic alkalosis

A

cause: diuretic use, diarrhoea

mechanism: chloride loss causes alkalosis

  1. impaired HCO3 secretion
  2. fall in ECF volume: decreased GFR, decreased filtered HCO3, increased Na reabsorption, increased NaHCO3 reabsorption, increased K excretion, increased NH4 excretion, increase HCO3

chloride responsive: renal cause (Ur Cl>40)

  • Barttner’s, Giltelman’s, diuretics

chloride responsive: non renal cause (Ur Cl<25)

  • vomiting, diarrhoea, CF

chloride resistant (volume overload/hypertensive)

  • mineralocorticoid excess or impaired Cl- excretion
74
Q

Multicystic dysplastic kidney

A

incidence: 1:3000, sporadic not inherited

pathogenesis: failure of ureteric bud to fuse metanephros

  • renal parenchyma replaced non-communication cysts
  • non functioning kidney with atretic/obstructed ureter

clinical:

  • 30% abnormal contralateral side, PUJ obstructions 15%, VUR 10%
  • usually normal renal function

treatment: nephrectomy if symptoms

prognosis: cysts involute 5 yrs, malignant change possible, RF uncommon

75
Q

Neonatal electrolyte disturbances

A

hyponatraemia:

  • early: excess TBW and normal Na
  • later: renal causes

hypernatraemia:

  • almost always hypovolaemic hypernatraemia
  • preterm: insensible losses
  • term: poor feeding

hypokalaemia:

  • excess renal loss K

hyperkalaemia:

  • renal failure, haemolysis, tissue destruction
76
Q

Neonatal renal function

A

antenatal

  • urine from week 10 gestation
  • small volume but 60% AF
  • oligohydramios: eg. PUV
  • polyhydramnios: eg. nephrogenic DI, Bartter’s
  • Cr crosses placenta: neonatal Cr= maternal Cr

postnatal:

  • relative renal insufficiency: low BP, high SVR, poor tubular reabsorption Na/HCO3
  • initially low urine vol, poor urine concentration, GFR 10-15ml/min
77
Q

Nephritic syndrome

A

‘Ho Hum’

Haematuria

Oliguria

Hypertension

Uraemia

Mild proteinuria

78
Q

Nephrocalcinosis

A

definition: laying down of calcium in the kidney in nondiscrete locations

incidence: common <1 week and disappears with urine production

pathology: lays around renal pyramids first

causes: same as for metabolic calculi

  • hyperoxaluria
  • hypercalciuria
79
Q

Nephrogenic diabetes insipidus

A

definition: partial or complete renal resistance to ADH

cause: hereditary or acquired

pathophysiology: urine output determined by solute intake/excretion

treatment:

  • low salt/protein diet

**protein highest renal solute load, best control UO

  • diuretics (increase proximal Na/H2O reabsorp and reduce distal water delivery)
  • NSAIDs (inhibit renal PG synthesis/afferent vasodilation)
  • exogenous ADH (only for non hereditary)
  • water q2 hourly day and night
80
Q

Juvenille nephronophthisis

A

incidence: most common cause of genetic cystic disease, incidence: 1:50,000

genetics: AR, chromosome 2, NHPH1-6

pathogenesis: ciliary defect causing problem with apotosis causing tubular BM thickening/wrinkling with tubular atrophy/fibrosis and few cysts at CM junction

3 variants:

  1. infantile: 1yr with ESKD
  2. juvenille (most): 13yrs ESKD
  3. adolescent: 19yrs ESKD

clinical:

  • renal (due to tubular injury): polyuria/polydipsia, reduced concentrating ability, Na loss, renal failure, anaemia

* normal BP

US: loss of CM differentiation, normal/small size

treatment: nil specific, renal transplant

81
Q

Nephrotic syndrome

  • definition and pathology
A

4 criteria

1. proteinuria >50mg/kg/day

2. hypoalbuminaemia <25

3. oedema

4. hyperlipidaemia: liver compensation for decreased albumin so increased other protein production

incidence: M>F 2:1, <6 yrs usually MCNS, >6yrs FSGN

clinical:

  • usually present with oedema first
  • then anorexia, abdo pain, cool peripheries

pathophysiology: effacement of podocyte foot processes

causes:

- steroid sensitive: no known cause

- steroid resistant: associated with genes for proteins podocin, nephrin, WT1

associated:

- infections: encapsulated, urinary loss Ig and C3 precursor

- thrombosis: 2-5% in children due to hypercoagulable state from stasis, haemconcentration, increased factor production, urinary loss anticoagulants

- hyperlipidaemia

82
Q

Nephrotic syndrome

  • causes
A

primary causes:

minimal change disease (85%):

  • EM effacement foot processes
  • 90% sensitive to steroids and rarely ESKD

focal segmental glomerulosclerosis (most severe):

  • LM mesangial proliferation/segmental scarring
  • IF +ve IgM/C3
  • EM segmental scarring of glomerular tufts/obliteration capillary lumen
  • 20% respond to steroids and most ESKD

mesangial proliferation:

  • LM increased mesangial cells/matrix
  • IF mesangial IM/IgA staining
  • EM increaesd mesangial cells/effaced epithelium
  • 50% respond to steroids

secondary causes:

  • any of GN: SLE, HSP, membranoproliferative, PSGN
  • malignancy (immune complexes with tumour Ag deposit in glomeruli
  • drugs: lithium, gold, phenytoin, NSAIDs
  • infection: HIV, hepatitis, malaria, syphillis
83
Q

Nephrotic syndrome

  • treatment
A

treatment

  1. high dose steroids tapered 4 months
    - 6 weeks 60mg/m2/day then 4 weeks 40mg/m2/day and taper
    - high dose and long course prevents relapse
    - 40 % relapse, 90% respond to steroids in 3 weeks

2. frusemide

3. fluid restrict

4.albumin

5. antihypertensives

definition of relapse: 3x >3+ protein in urine

treatment of relapse: 60mg/m2/day until remission (urine negative 3/7)

steroid dependent: relapse on alternate days or within 28 days ceasing

steroid resistant: ongoing proteinuria at 8 weeks, 80% FSGN, need biopsy

  • consider cyclosphospamide, rituximab

prognosis:

  • steroid responsive: most have repeated relapses, decreased frequency with age
  • steroid resistant: poorer prognosis, renal insufficiency
84
Q

Obstructive uropathy

A

causes: PUJ obstruction, renal calculi, thrombi, tumours

Ureteric stricture

  • congenital with extrinsic compression where the right ureter sits behind IVC

Ectopic ureter

  • F>M, ureter enters urethra/cervic/uterus
  • reimplantation if renal function is preserved otherwise nephrectomy

ureterocele

  • cystic dilation at end of ureter
  • surgical resection/correction
85
Q

Osmolarity

A

calculated plasma osmolarity= 2[Na+Ka] + glucose + urea

plasma osmolarity= 280-295 mosmol/l

86
Q

osmoles

A

osmolality= no. of osmoles/kg of solutes (mosmol/kg)

osmolarity= no. of osmoles/L of solution (mosmol/L)

87
Q

Oxalate calculi

A

incidence: RARE. genetic

mechanism: overproduction oxalate in liver due to primary or secondary disease

clinical: reccurent nephrolithiasis and progression to ESKD

treatment: pyridoxine, fluids, transplant

88
Q

Oxybutynin

A

mechanism: anticholinergic

- prevents muscarinic recepter activation by anticholine on bladder smooth

use: decreases bladder spasm to prevent incontinence

89
Q

Peritoneal dialysis

A

dialysate contains: osmotic agent, electrolytes, acid buffer

ultrafiltrate: fluid removed from patient

volumes: 10-50ml/kg each cycle

contraindications: intraabdominal pathology, peritonitis

advantages: gentle, less fluid shift, higher peritoneal SA in children, no central venous access devise

disadvantages: infection (IP ceftazidime/ceftriaxone or if <2yrs IP ceftaxidime/vancomycin with continuous PD), peritoneal fibrosis, career burnout

90
Q

Pneumococcal HUS

A

incidence: 5-15% HUS, younger 1-2yrs

pathophysiology: pneumococcus produces neuroaminidase and exposes T antigen on RBC/platelets (cryptantigen considered FB) causing haemolysis

clinical: pneumonia (70%) with empyema/effusion, meningitis (20-30%)

  • more severe initial disease
  • complications: pancreatitis, purpura fulminans, cholecystitis, cardiac dys, hearing loss

treatment: supportive

91
Q

Post renal AKI

A

mechanism: obstruction

pathophysiology:

  1. collecting tube dysfunction (type 4 renal tubular acidosis)
    - water/Na loss, H/K retained
  2. more proximal dysfunction
    - RAAS, reduced GFR, ATN
  3. ATN assoc sepsis
    - poor outcome
92
Q

Post strep glomerulonephritis

PSGN

A

type: diffuse proliferative glomerular injury with inflammation

incidence: 5-12 yrs, 15% post GAS infections, increased with family history

pathophysiology: GAS infection, diffuse mesangial cell proliferation, glomerular inflammation

  • usually GAS but also EBV, CMV, HepB, endocarditis

clinical: 1-2 weeks post throat infection/3 weeks post skin infection

  • gross haematuria, flank pain, oliguria, HTN, oedema, hyperkalaemia, hypocalcaemia
  • MRI can show reversible posterior leukencephalopathy

diagnosis:

  • low C3, normal C4, ASOT+ (throat 90%, skin 50%), AntiDNAse B+ (95% spec)

- urinalysis: protein, casts

- biopsy: IgG/C3 deposits, diffuse proliferation

treatment: dialysis, fluid restrict, frusemide

  • NO STEROIDS

prognosis: 95% fully recover

  • micro haematuria may persist for 1 yr
  • 5% relapse or ESKD
93
Q

Posterior urethral valve

A

pathophysiology:

  • embryological remnant: a valve with leaflets with only a slit like opening at a point along the urethra

clinical: severe obstructive uropathy

  • poor urinary stream, trabeculated bladder, ESKD 30%

diagnosis: often diagnoses antenataly with hydronephrosis, oligohydramnios, pulmonary hypoplasia

associations: VUR, dysplastic kidney

treatment: antenatal decompression, IDC/vesicostomy, valve ablation, prophylactic AB, monitor renal function

94
Q

Potassium sparing diuretics

amiloride/spironolactone/eplerenone

A

mechanism: act on cortical collecting duct

  • amiloride: directly decreases Na channel activity
  • spironolactone: inhibits aldosterone receptor and decreases number of Na/Cl cotransporters

effect: weak natriuretic activity with only 2% filtered Na excreted

side effects: hyperkalaemia, gynaecomastia

  • amiloride: hyperchloremic met acidosis, hyponatraemia
95
Q

Predictive Acid/Base

A

Respiratory compensation 1 CO2: 1 HCO3

  • 30 mins-24 hrs

met acidosis: decrease pCO2 1.3 for decrease 1 HCO3

met alkalosis: increase pCO2 0.6 for increase 1 HCO3

Metabolic compensation

  • 1 to 5 days

resp acidosis ACUTE: increase HCO3 1 for increase 10 CO2

resp acidosis CHRONIC: increase HCO3 3.5 for increase 10 CO2

resp alkalosis ACUTE: decrease HCO3 2 for decrease 10 CO2

resp alkalosis CHRONIC: decrease HCO3 3 for increase 10 CO2

96
Q

Prerenal AKI

A

cause: hypovolaemia, poor perfusion, sepsis, CV failure

pathophysiology to counter hypovolaemia:

  1. intrarenal PG release: dilation afferent arteriole and improve filtration
  2. decreased pressure at macula densa, increase renin/ATII, selectrive vasoconstriction efferent arteriole, increased hydrostatic pressure across glomerulus
  3. further increase renin/ATII, systemic vascoconstriction afferent/efferent arterioles, ATN and oliguric RG
97
Q

Proteinuria

A

definition: >4mg/m2/hr

diagnosis: early morning protein to creatinine ratio most reliable

dipsticks: most sensitive for albuminuria and miss other proteinurias

  • 1+ 30mg/dl
  • 2+ 100mg/dl
  • 3+ 300mg/dl
  • 4+ 2000mg/dl

non-pathological: exercise, fever, posture

pathological: tubular, glomerular, tumour, drugs, stone, infection

98
Q

Proximal RTA

type 2

A

definition: inability to reabsorb HCO3 (and Na)

cause: can be isolated or generalised proximal dysfunction

ie Fanconi’s syndrome: genetic or acquired

  • decreased PO4, renal glycosuria, aminoaciduria, tubular proteinuria, T2 RTA

causes of isolated proximal RTA

  1. idiopathic
  2. cystinosis
  3. ifosfamide

diagnosis: acidic urine <5.5, NH4 in urine, NO calculi (citrate present)

treatment: BICARB

99
Q

Proximal tubule function

A

iso-osmotic reabsorption of 2/3 glomerular filtrate

active reabsorption: Na, K, glucose, galactose, fructose, AA, Ca, uric acid, Vit C

passive reabsorption: urea and water due to osmotic gradient generated by solute reabsorption

active secretion: organic acids eg. PAH, diuretics, salicylates, penicillin, probenicid

100
Q

PUJ obstruction

-pelvicoureteric junction-

A

incidence: most common obstruction, M:F 2:1

pathophysiology: congenital instrinsic stenosis (90%) and less commonly extrinsic compression (10%) causing partial obstruction of the ureter resulting in thin ureter and dilated kidney

  • 60% left, 10% bilateral

diagnosis:

US: hydronephrosis

MCUG: detect VUR (10%)

DTPA: diagnose obstruction

management: AB prophylaxis, pyeloplasty (91-98% success)

101
Q

RAAS

A

causes of increased renin:

  • decreased BV/Na concentration
  • catecholamines
  • standing

causes of decreased renin release:

  • angiotensin II, ADH, hypernatraemia, hypokalaemia
  • indomethacin/beta blockers/ACEi
102
Q

Renal absorption/secretion other molecules

A

hydrogen: secretion 85% PCT, 10% distal tubules, 5% CD in exchange for Na

  • via 3 mechanisms

chloride: moves passively with Na except for active transport in LOH

sugar/AA: completely reaborbed in PT via Na dependent active transport

  • glucose is saturable: at 10mmol/l glycosuria occurs

urea: 87% filtered reabsorbed (50% in PT)

water: passively reabsorbed 80% PT, 15% LOH, distal tubule via ADH

103
Q

Renal acid output

A

Renal H+ excretion

  • minimal H+ excretion but excrete H+ via NH4

Urine anion gap

  • urine ammonia can be estimated by the UAG:

UAG= (urine Na + urine K) - urine Cl

  • usually Na + K > Cl

Acidosis

  • increased excretion of NH4 combines with Cl to make ammonium Cl and increases renal Cl so Cl> Na + K

Urine pH

  • if high: bicarb in urine
  • if low: H+ present
104
Q

Renal acid/base

A

1. Renal bicarb reabsorption

  • H+ secretion tubular cells binds HCO3- to form H2CO3 that divides to CO2/H20 with reabsorption of CO2 into tubular cells

2. Ammonium secretion

  • NH3 in tubular cells accepts H+ to form NH4+ which is then excreted

3. Dihydrogen phosphate

  • exchange H for Na converts monohydrogen phosphate to dihydrogen phosphate (acid)

**Excess H+: 2/3 excreted as annium, 1/3 excreted as dihydrogen phosphate

105
Q

Renal angiomyolipomata

A

incidence: most common benign tumour kidneys

  • 1/10 in patients with TS

pathogenesis: benign tumour of blood vessels

clinical: retroperitoneal haem with sudden pain, nausea, vomiting, shock

renal US: bilateral multiple echogenic foci

106
Q

Renal biopsy

A

differention:

  • proliferative vs non proliferative
  • diffuse vs focal
  • segmental vs global
  • crescenteris: cellular vs fibrous types

specific patterns:

  • cresenteric= RPGN
  • tram tracking= MPGN
  • wire loops= SLE
  • spikes on special stains= membranous
  • starry sky= PSGN
  • subepithelial humps (immune complexes on GBM)= PSGN

immunofluorescence: c3, IgA/M/G, C1q

  • granular= immune complex
  • pauci immune= ANCA assoc
  • linear IgG at GBM= antiGBM
  • gull house pattern (all present)= SLE

electronmicroscopy: good for the site of immune deposition

107
Q

Renal calculi

A

incidence: M>F, 1% children, 60% metabolic risk factor

  • variables: diet, geography, race, family history

diet: increased protein/cereal, high or low calcium, high salt

stone composition:

  • calcium oxalate 60-90%
  • calcium phosphate 10%
  • struvite 1-14%
  • urate 5-10%
  • cystine 1-5%

formation: forms in tubules at site of injury usually in medulla

clinical: flank pain (50%), renal colic (7%), haematuria (10% macro, 90% micro), passage of stone, UTI, CKD

  • chance of passing stone <5mm high, 5-7 mm 50%, >7mm review

diagnosis:

  • US: detects stone, shows obstruction
  • urine/stone analysis

complications: UTI (FTT and intermittent urosepsis), functional impairmonet, decreased bone density

108
Q

Renal clearance

A

clearancex= [urinex] x urine volume/[Plasmax]

  • if clearance>GFR: secretion of solute
  • if clearance<gfr: absorption of solute>

<p><strong>clearance of solute</strong></p>

<p>- ideal solute: freely filtered at glomerulus, no metabolism/secretion/reabsorption ie. inulin</p>

<p><strong>creatinine:</strong> small endogenous product muscle metabolism</p>

<p>- secreted in tubules so can overestimate GFR</p>

<p><strong>urea: </strong></p>

<p>- 40-50% passively reabsorbed in proximal tubule</p>

<p>- can underestimate GFR</p>

<p><strong>cystatin C: </strong>small molecule produced nucleated cells in body</p>

<p>- metabolised in tubules so can't measure clearance</p>

<p>- BUT serum cystatin C may correlate better with GFR</p>

<p> </p>

</gfr:>

109
Q

Renal cysts

A

pathogenesis: problem non-motile cilia from tubular epithelial cells facing lumen

  • loss of tubule orientation causing dilation and cysts

polycystic: ARPKD, ADPKD, MCDK

CAKUT: renal agenesis, dysplasia, aplasia

tubulointerstitial: renal tubular dysgenesis, nephronopthisis, medullary cystic disease, Bardet-Biedl

neonplasms: cystic nephroma/nephroblastoma/RCC, von Hippel Lindau, lymphangioma, hygroma renalis

other: simple corticol cyst, medullar sponge kidney, localised renal cystic disease

110
Q

Renal cysts and diabetes syndrome (RCAD)

A

genetics: AD, HNF1B activates polycystin/uromodulin

clinical: DM (20-40yrs), gout, bicornuate uterus, hypomagnesiua, LFTs

111
Q

Renal embryology

A

timing: 5 weeks gestation, glomerulus development at 9 weeks, urine output 10 weeks

phases

1st: Pronephros day 22

2nd: Mesonephros

  • mesoderm in thoracolumbar region develops into glomeruli/tubules

3rd: Metanephros week 5

  • outpouch of mesonephros forms ureteric bud branches into the ureter and collecting duct system

completion: weeks 32-36 all nephronic units complete

112
Q

Renal management of sodium

A

Na reabsorption (99% of filtered)

  • 60% PCT: Na/H exchanger (H provided by HCO3 absorption and carbonic anhydrase)
  • 25% LOH (thick ascending limb): Na/Cl/2K co transported
  • 10% DT: epithelial Na channel coupled to K
  • 2% CT

Na regulation by Aldosterone/ANP

  • mediate plasma volume NOT Na

Fraction excretion of Na: % of Na filtered by kidney excreted in urine

  • (FENa)= 100x (Nau x Crp)/(Nap x Cru)
  • <1%: prerenal disease, 1-2%: ATN or prerenal, >2%: ATN
113
Q

Renal osteodystrophy

mineral bone disease

A

prevalence: very common early on with CKD

pathogenesis:

- decreased renal mass causes decreased renal 1 alpha-hydroxylase and 1, 25 vitamin D3 production

  • decreased GI calcium absorption and hypocalcemia, and increased PTH activity
  • excessive PTH secretion corrects hypocalcemia by increased bone resorption
  • later mechanisms to enhance phosphate excretion inadequate causing hyperphosphatemia with further hypocalcemia and increased PTH

4 types:

1. Osteitis fibrosa cystica: increased bone turnover due to secondary hyperPTH

  • increased PTH due: increased Ph, decreased Ca/VitD

2. Adynamic bone disease: decreased bone turnover

  • most common renal bone disease
  • decreased osteoblast/osteoclast activity
  • over suppression of PTH (vit D tx, Ca based phosphate binder)

3. Osteomalacia: decreased bone turnover and more undermineralised bone

  • common when Al would deposit in bone with Al based Ph binders

diagnosis: PTH, ALP, BMD testing, bone biopsy

management: control of PTH and PO4

114
Q

Renal reabsorption

A

PCT (65%): site of signficant reabsorption (NaCl, water, HCO3, nutrients) and excretion (H, drugs)

LOH (25%): countercurrent mechanism, descending limb impermeable to solutes and reabsorbs water, ascending limb impermeable to water and Na/Cl/K reabsorbed

DCT (8%): electrolyte reabsorption in smaller shifts

CD (1.5%): site ADH/aldosterone action

  • Aldosterone: Na/water retention, K/H secretion, stimulates ADH
  • ADH: acts on cortical part of CT

NB. % Reabsorption of solutes

115
Q

Renal transplant

A

types: preemptive, living related donor, deceased donor

graft survival: approx 15 years

immunosuppresants: steroids, basiliximab for induction (anti CD25 monocloncal Ab), tacrolimus/cyclosporine (calcineurin inhibitors), azathioprine/MMF (antiproliferative agents), sirolimus/everolimus (mTOR inhibitors)

complications:

rejection: creatinine best indicator of rejection

  • hyperacute: preexisting HLA Ab, occurs anytime
  • acute: T cell medicated, interstitial inflammation/arteritis, treat with methylprednisone/anti-thymocyte globulin
  • chronic: donor specific antibiodies, CD4 staining on biopsy, glomerulitis/vascular thrombosis, optimise immune suppression

infection: EBV, CMV, BK

NODAT (new onset diabetes after transplant): same as DM2, increased BMI/steroids

PTLD (post transplant lymphoproliferative disease): related to infection, treat with reduced immunosuppression, monitor EBV levels

malignancy: most adults, skin (SCC/BCC), increased all types due to immune suppression

116
Q

Renal tubular acidosis

A

definition: normal AG acidosis but failure to acidify urine

types:

  • distal (type 1) RTA
  • proximal (type 2) RTA
  • mixed (type 3) RTA
  • type 4 RTA

treatment: treat underlying condition, sodium bicarb

complications: lactic acidosis, hypernatraemia, volume overload, hypokalaemia, hypocalcaemia, alkalosis

117
Q

Shigatoxin HUS

A

epidemiology: 90% all cases usually <5years, 3/100,000

organism: 6-9% STEC infections

pathophysiology: microangiopathic anaemia by nonimmune RBC destruction due to shearing through platelet microthrombi

  • glomerular thrombotic microangiopathy with can extend to afferent arteriole

clinical: preceded 5-10 days before with abdominal pain, vomiting, blood diarrhoea usually post exposure to undercooked beef

  • AKI 50%
  • neurological symptoms 25% and seizures assoc HTN
  • GI haemorrhagic colitis
  • also cardiac dysfunciton, pancreatitis, liver dysfunction, haem disorders

prognosis: 30% CKD, 5% mortality

treatment: fluids, dialysis, eculizumab (monoclonal complement Ig), plasma exchange

118
Q

Single renal cyst

A

incidence: sporadic, M>F 2:1

cause: unknown

diagnosis: cortical, solitary, unilateral

clinical: pain, haematuria, obstruction, rupture, infection

119
Q

SLE glomerulonephritis

A

type: diffuse

epidemiology: 25% SLE in children

pathogenesis: minimal change (mild, haematuria/proteinuria), mesangial (mildest 25%, haematuria/proteinuria), FSGN (20%, + impaired RF), diffuse proliferative (most common/severe 40%, + impaired RF), membranous (15%, nephrotic syndrome), advanced sclerosis

diagnosis: (FULL HOUSE)

  • low C3/C4, ANA+ve, ESR, dsDNA+ve
  • biopsy: wire loops, all stains positive: IgG, IgA, IgM, C3, C1q

treatment: steroids, immunomodulators, IVIg, ACEi, statin

prognosis: ESKD 20% at 10 yrs

120
Q

Thiazide diuretic

A

mechanism: inhibit Na transport in DT via inhibition NaCl cotransported

  • also cause increased reabsorption of calcium

effect: smaller proproportion of filtered load, so smaller natriuretic effect

side effects: hyperglycaemia, hypokalaemia, hyperuricaemia, hypercalcemia, hypochloremic alkalosis

121
Q

Transplant rejection

A
122
Q

Tubular renal disease

A

ATN:

cause: ischaemic 60%, nephrotoxic 40%: aminoglycosides, chemotherapy (cisplatin), IVIG, contrast

pathophysiology: oedema, sloughing of cells, Na/K pump dysfunction

management: hydration, nutrition, time

Contrast nephropathy/dermopathy:

cause: CT contrast, MRI gadolinium (lower toxicity)

pathophysiology: rise Cr after 48 hours

  • MRI gadolinium associated nephrogenic systemic fibrosis if GFR<3

management: hydration, ?NAC (free radial scavenger)

123
Q

Urate calculi

A

causes: disorders of purine metabolism (5-10%), uric acid overprod, tumour lysis, Lesch-Nyhan, gout, ketogenic diet, salicylates, glycogen storage 1

treatment: alkalinise urine, ?allopurinal, uricase

124
Q

Urinanalysis

A

specific gravity: normal 1.010-1.035

osmolality: normal 300mosm (more accurate than SG)

microscopy

urinary casts: cylindrical structures produced by kidney (DCT/CD) and present in urine

  • hyaline casts: transparent, most common, solidified Tamm-Horsfall mucoprotein secreted from the tubular epithelial cells of nephrons with dehydration/exercise, not pathological
  • granular casts: 2nd most common, breakdown of cellular casts or inclusion of aggregated protein, glomerular/tubular disease

- white cell casts: indicate inflammation/infection ie. acute pyelonephritis, interstitial nephritis

  • red cell casts: always pathological, usually glomerulonephritis
  • fat globules: hyperlipidaemia
  • glycosuria: steroids, FSGS
125
Q

UTI

A

incidence: 7% febrile infants

  • <12 months M=F, <3 months M>F

risk factors: FHx, abnormal flow, constipation, abdo mass, antenatal dx renal abnormality, HTN

definitions:

  • cystitis: bacteruria but no systemic symptoms
  • pyelonephritis: bacteriiuria + fever/pain

pathogens: ecoli (>80%), klebsiella, proteus, enterobacter, enterococcus

diagnosis:

  • leuks+/nitrites+: AB
  • leuks-/nitrites+: AB
  • leuks +/nitrites-: AB IF clinical evidence
  • leuks-/nitrites-: DONT treat

treatment:

  • <6m or unwell: IV AB (benpen, gent)
  • >6m and not unwell: PO AB (trimethoprim, bactrim, ceph)
126
Q

Prune belly syndrome

VUJ obstruction

A

incidence: 1/40,000, 95% male

triad: lack of abdominal muscles, undescended tests, antenatal urethral obstrution

clinical: oligohydramnios, pulmonary hypoplasia

  • often assoc malrotation

prognosis: dependes on pulm/renal dysplasia

127
Q

Wegener’s

PR3 ANCA

microscopic polyangitis

MPO

A

incidence: usually adults with sinusitis/renal/skin involvement

pathophysiology: focal segmental GN (may be crescenteric), NO immune deposits (oie. pauci immune)

clinical:

  • systemic disease: ENT/pulmonary
  • microhaematuria, AKI with haematuria/casts, proteinuria below nephrotic range, RPGN common

diagnosis: ANCA +ve

  • biospy: ANCA
  • immunofluorescence: pauci immune

treatment: non specific

  • dialysis, steroids, immunosuppressants, IVIg
128
Q

Atypical UTI

A

CRITERIA:

  • seriously ill/septicaemia
  • poor urine flow
  • abdominal mass
  • elevated creatinine
  • failure to respond to appropriate AB within 48 hours
  • non Ecoli organisms

FRACP Exam (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions