Renal Learning Points CSV Flashcards
Renal differences in the neonate (6)
(1) nephron number multiplies until 36/40 (increased risk hypertension in preterm)
(2) decreased GFR in preterm
(3) oliguria then polyuria (K wasting in polyuric phase)
(4) ADH increases at birth and can be very high in HIE
(5) renal wasting of bicarb - can be acidotic
(6) renal wasting Calcium
what are nephropathies have low C3
5 S’s: 1. post Strep, 2. MeSangioProliferative/Membranous GN, 3. SLE, 4 Septic (SBE, HBV, HCV) 5. Shunt nephritis
Normal complement nephropathies
4 A’s and H: 1. Alport 2. Anti-GBM (Goodpastures) 3. IgA, 4. ANCA associated (Wegeners) & HSP
When will children with HSP develop nephritis by?
by 6-8 weeks but need to be monitored for 6 months
renal biopsy indications
nephritic/nephrotic at presentation,
persistently impaired/deteriorating renal function,
C3 low at 3 months
IgA nephropathy characteristics
Not inherited
gross haematuria with illness, recurrent,
flank pain,
persistent microscopic haematuria
benign in childhood but HTN in adult - treat with ACEi
Alport syndrome characteristics
hearing loss (age 10),
EYE abnormalities (macular flecks)
recurrent gross haematuria post viral ilness persistent microscopic haematuria,
ESRD late teens
With nephropathies are rapidly progressive?
crescents >50% glomeruli ANCA associated (pauciimmune) Anti-GBM (Goodpastures - pulm-renal syndrome) SLE (systemic symptoms) Membranoproliferative (low complement) HSP (IgA)
Definition nephrotic syndrome & most common cause
Oedema,
Proteinuria (uPCR >200, 3+ protein),
Low Alb <25 .
Most common cause = minimal change disease
what explains oedema in minimal change disease
reduced oncotic pressure and increased sodium reabsorption
Complications of nephrotic syndrome
hypothyroidism, rickets, thrombosis, short stature, anaemia
best way to calculate GFR in clinical setting
plasma disappearance of radio-isotope
**inulin gold standard but only in research setting
when does GFR reach adult values
age 2
Triad of HUS
Thrombocytopenia,
Haemolytic anaemia,
Acute kidney injury
Typical HUS - causes
diarrhoea related - E.Coli 0157:H7 - verotoxin/shiga toxin
Shigella – shiga toxin
HUS Atypical causes
Pneumococcal
*Complement (C3, CD46, factor B, H inhibitors) , *ADAMTS13,
Cobalamin deficiency
*lead to activation of alternative complement
what does ADAMTS13 do
acts to cleave vWF multimers and prevent thrombus formation
Long term sequelae HUS
“Microangiopathy” diabetes,
Hypertension,
Proteinuria
CKD
What is the most predictive risk factor for long term sequelae in HUS
duration anuria >10 days,
prolonged dialysis >7 days
Duration follow-up of HUS? ** need to know
at least 5 years as long term sequelae can occur up to 5 years post apparent recovery
Clues to chronic glomerular causes to CKD
Oligouria,
Haematuria/proteinuria,
Hypertension
Clues to tubular disease for CKD
Polyuria, Polydipsia
Sodium loss,
Enuresis
Progression of CKD can be slowed by?
Control HTN,
Control proteinuria,
Treatment anaemia,
Treatment hyperlipidaemia
Complications CKD
- Growth failure
- Osteopenia
- Anaemia,
- Acidosis (impairs GH release),
- Water and electrolyte imbalance,
- Delayed puberty,
- Social and cognitive.
What are the bacteria in bacterial peritonitis in a child with PD? Antibiotics?
Treat if WBC >50 and symptomatic or WBC >100
Bacteria = staph epi, staph aureus
Antibiotics = Cefazolin, ceftazidime OR vancomycin & ciprofloxacin
Causes of PD peritonitis
- Intraluminal (touch contamination),
- Periluminal (tunnel infections),
- Intestinal translocation
- Systemic,
5 Ascending (rare)
Benefits transplant over dialysis
- Mortality,
- CVD,
- Growth,
- Neurodevelopment,
- QOL
Absolute contraindications to renal transplant
- active malignancy,
- severe neurological dysfunction,
- terminal illness / multiorgan failure,
- psychiatric illness impairing consent
6 causes of allograft dysfunction
- Dehydration,
- Medication
- Infection,
- Obstruction
- Rejection (biopsy)
- Perfusion problem
Hypertension Treatment post renal transplant
Ca channel blockers (early),
Diuretics (if hypervolaemic)
ACEi once 2-3 months post t/p
Tacrolimus SE
nephrotoxicity, HTN, hepatic dysfunction, glucose intolerance, hyperkalaemia, hypomagnesaemia, alopecia
Tacrolimus mechanism of action
calcineurin inhibitor > inhibits nuclear activation
Cyclosporin SE
neprotoxicity, HTN, gigival hyperplasia, hirsutism, hyperuricaemia, hypercholestoraemia
Pulmonary renal syndrome causes
[Pneumonic AA STD] - Anti-GBM, ANCA, SLE, Thrombotic disease (antiphospholipid, TTP, HSP), Drugs
RIFLE criteria
For renal insult - Risk dysfunction (Crx1.5), Injury (Crx2), Failure (Crx3), Loss (>4weeks), ESKD (>3months)
Causes hypochloraemic metabolic acidosis
pyloric stenosis, prolonged vomiting, diuretics, Bartter, CF, Choride diarrhoea
RTA type 1
DISTAL, can’t excrete acid, hypercalciuria (stones), urine is alkaline (ph >5.5) loin pain Low K CAUSES: obstructive uropathy, marfan, wilsons, drugs (amphotericin)
RTA type 2
PROXIMAL, can’t resorb bicarb, hypercalcaemia / low calcium in urine
acidic urine (pH <5.5)
Low K
CAUSES: cystinosis, fanconi
Fanconi
ALL of proximal tubule short child no growth and vomiting. Renal >GI losses occurs at time that transitions from breast milk to cows milk ~6 months age - hypophosphataemic ricketts - amino acid uria, glycosuria, - normal glucose in plasma
RTA type 4
normal urine anion gap,
hyper aldosteronism
High K, Low Na
CAUSES: CAH, tacro, NSAIDS, tubular aldosterone def
Bartter Syndrome
Na/K/2Cl Channel defect in LOH - hypochloraemic hypokalaemic metabolic alkalosis Hypercalciruia, hyperchloride uria Prone to hypernatraemic dehydration Manage with NSAIDS > slow GFR
Gitelman syndrome
NaCl defect in distal tubule
hyPOcalciuria
present later in childhood with cramps - LOW Mg
metabolic alkalosis with volume contraction (normal/low BP)
ABCD - Anorexic (vomiting/laxatives), Bartter, CF, Diuretics.
metabolic alkalosis with volume expansion (high BP)
Anything that activates RAAS:
- Aldosteronism,
- Renal artery stenosis,
- Renin producing tumour,
- Adrenal carcinoma,
what level are the kidneys? Which kidney is larger? How much size discrepancy is normal?
Level T12-L3,
Left larger than Right,
10% difference in size is normal.
What percentage of cardiac output reaches kidneys?
20-30%
what part of the LOH is high permeable to water?
(thin Loop of Henle) highly permeable to water;
Glomerular basement membrane structure
Capillary > endothelium > Basement membrane > podocyte
3 Factors affecting filtration through basement membrane
(1) Size <3nm
(2) charge negative (repels albumin),
(3) protein binding
When does GFR reach adult levels?
2 years of age
3 activators of renin-angiotensin system
Sympathetic nervous system;
hypotension / low RBF,
Oedema
6 suppressors of renin-angiotensin
Angiotensin 2; ADH; Hypernatraemia/Hyperkalaemia; NSAIDs; Betablockers; ACEi
Renin-angiotensin system
renin (kidneys) converts angiotensinogen (liver) to angiotensin 1 which is then converted to angiotensin 2 (via ACE from lungs).
6 Actions angiotensin 2
(1) systemic vasoconstriction
(2) Thirst
(3) ADH release
(4) Aldosterone release
(5) constriction efferent >afferent arterioles
(6) Proximal tubule sodium absorption
what undergoes sodium co-transport in the proximal tubule?
Glucose, AA, lactate, Cl, Phos
Actions Loop of Henle
countercurrent mechanism
thin descending loop = passive movement of water
thick ascending limb = active pump
Fluid changes from isotonic > hypertonic > hypotonic
Action aldosterone
increase Na reabsorption
excretion K and H
Actions ANP
triggered by hypertension tries to oppose it
dilates afferent and contracts efferent arterioles > Increased GFR and diuresis
inhibits aldosterone, renin, ADH
Actions of PTH on kidney
increase Ca reabsorption and phosphate excretion
Actions prostaglandins
dilate afferent arteriole
Polyhydramnios associations
Maternal GDM,
GIT obstruction (TOF, atresia),
Increased output (Bartters, congenital Cl and Na diarrhoea),
CNS failed swallowing
Raised AFP associated with
neural tube defect,
congenital nephrotic syndrome,
epidermolysis bullosa
Radiology tests for renal function
MCU - PUV voiding dysfunction
DMSA (M=Meat) renal scarring,
DTPA (T=tubules) split renal function
MAG3 best for VUR
What layers do nephrotic and nephritic syndrome affect?
Nephrotic - podocyte layer and GBM
Nephritic affects ALL layers hence haematuria, proteinuria, hypertension, AKI, oedema
Diagnosis and bacteria in spontaneous peritonitis in nephrotic syndrome
strep pneumonia
Diagnosis = WCC >250, PMN>50, pH <7.35
Features congenital nephrotic syndrome
AR, NPHS1 gene, antenatal increase AFP, low birth weight and large placenta, heavy proteinuria, tubular dilatation with microcytic change, baby can have Potter syndrome
OR AR NPHS2 gene (podocin), presents 3-5 years of age with steroid resistant nephrotic syndrome.
Most common cause of idiopathic nephrotic syndrome, features and treatment.
Minimal change disease, 2-3 years of age, NORMAL complement, treatment with steroids 90% respond, ACEi, 2nd line cyclosporine, also immunisation, penicillin, aspirin
What is definition of relapse of nephrotic syndrome?
2+ proteinuria for 3 days
Features of FSGS
Nephrotic syndrome, steroid resistant >6yoa, tea coloured urine, proteinuria, glycosuria, IgM and C3
Features masangiocapillary/membranoproliferative GN
Nephrotic syndrome,
Older child
LOW complement
Poor response to steroids
Features membranous GN
Nephrotic syndrome
older children,
Associated Hep B, SLE, malignancy
Most common causes haemanturia
Post strep GN
IgA nephropathy
Acute glomerular injury pneumonic
HOOHUP - haemanturia, oligouria, oedema, hypertension, uraemia, proteinuria
Rapidly progressive GN
ANCA,
Anti-GBM disease (Good pastures), Membranoproliferative GN
HSP
SLE
Features thin BM disease
AD but no chronic issues in family
Excellent prognosis
Features Good pastures
Anti GBM,
Older child
pulmonary renal syndrome
Features Shunt nephritis
Due to staph aureus most,
Subacute
LOW complement
Features Post Strep GN
Group A beta haemolytic strep 2 weeks post throat infection 1 month weeks post skin infection, ASOT + 1 month, DNAase B + 2 months (more specific) Resolves 2-3 weeks, 95% fully recover Penecillin prevents spread to contacts
Features SLE nephritis
teenagers,
females,
systemic = rash, oral ulcers, photosensitivity, arthritis, anti dsDNA +, renal, anaemia
Treat class 3-5 (3=focal glomerulosclerosis, 4=segmental/global proliferative nephritis, 5=nephrotic syndrome)
steroids>cyclophosphamide>ritixumab
Types ANCA associated nephritis
(1) granulomatosis with polyangiitis cANCA
(2) churg strauss eosinophillic pANCA
(3) microscopic polyangitis pANCA
(4) polyarteritis nodosa
(5) takagasu arteritis
differences between pre-renal and ATN
urine osmolality higher in pre-renal,
High urine Na in ATN
urine sediment is normal in pre-renal
indications for dialysis
hyperkalaemia, fluid overload resistant to frusemide, acidosis, urea >40, prolonged anuria, multi-system failure
fractional excretion of sodium
low is salt retaining, high if salt wasting 100 x (sodium in urine x creatinine in plasma)/(sodium plasma x creatinine urine)
features cystinosis
AR, cystine accumulation in lysosomes
hypophosphataemic rickets
growth failure
fanconi syndrome
most common renal stones are?
calcium oxalate
what factor is most important in managing persons with renal stones?
low salt diet - increase bone deposition and decreases calcium urine excretion
causes hypercalciuria and hypercalcaemia
hyperparathyroidism, vit D excess, immobilisation, hypophosphataemia, williams syndrome
causes hypercalciuria and normocalcaemia
idioapathic, immobilisation, medullary sponge kidney, drugs (frusemide, steroids), ketogenic diet, genetic
what decreases calcium in urine
potassium and citrate
features cystinuria
AR
urine hexagonal crystals,
raised COAL (cystine, ornithine,argentine,lysine) in urine,
treat with fluids, low salt, penecillamine, alkalinise the urine
rhabdomyolysis features, and treatment
high CK, K, Phos, Ur, LOW Ca.
Treat with fluids and allopurinol
conditions with cysts seen on USS of kidneys
multicystic kidney disease (dysplastic) autosomal dominant kidney disease, renal cysts associated with diabetic syndromes (MODY 5) simple cysts Tuberous sclerosis
features ADPCKD
PKD1/2,
cannot be excluded until 30 years of age,
cysts in other areas (liver), cerebral aneurysms, disease progression related to HTN.
features ARPCKD
PKHD1,
Large kidneys hyper echoic
Potter syndrome (contractures, pulmonary hypoplasia, typical facies),
hepatic Caroli syndrome - intrahepatic bile duct dilatation, fibrosis
features nephronophthisis
Ciliopathy, tubular disorder salt wasting > polydipsia, polyuria Anaemia Small smooth echogenic kidneys growth failure
features bardet biedl
obesity, developmental delay hypogonadism, polydactyly, Retinal problems renal nephronophthisis can't even eat, can't even see, can't even think, can't even pee
what immunosuppressives act in the S phase?
Prednisolone, Methotrexate, MMF, Azathioprine, cytarabine, doxorubicin, thioguanine
What does Sirolimus act on
mTOR, G1 phase
what immunosuppressives are cell cycle indepamdant
cyclophosphamide (alkylating agents)
Cisplatin
etoposide
ifosfamide
What monoclonal antibodies act as TNF inhibitors?
Adalimumab,
Ertanecept,
Infliximab
What monoclonal antibody acts on B cells?
Rituximab - Anti-CD20
Tocilizumab action
anti-IL6
Anakinra
Anti-IL1
Basilixumab
Anti-CD25 Treg cells
Multi-cyctic dysplastic kidney
No function
Contralateral kidney hypertrophy,
Low risk Wilms,
Nephrectomy cures hypertension.
Horseshoe kidney associations
VACTERL, Trisomies, fetal alcohol syndrome, infant diabetic mother. Associated renal carcinoma
Imaging for PUJ obstruction
MAG 3 scan
Posterior urethral valves
poor stream, bilateral dilatation
UTI male,
MCUG at diagnosis then DMSA + MCU 3 months.
Don’t use Foley catheter!!!
Poor prognostic factors obstruction
oligohydramnios
hydronephrosis 100 after decompression
cortical cysts
diurnal incontinence >5yoa
Prune belly syndrome features
absence abdominal wall muscles, megaureter/cysts,
Undescended testes
infertility
also other abnormalities
antenatal hydronephrosis
APD >15mm = severe
APD >10mm = mod
indications circumcision
balanitis obliterans,
paraphimosis,
recurrent balanitis/UTI,
phimosis failing steroid treatment
complications circumcision
UTI, wound infection, stenosis
contraindications to circumcision
hypospadia, micropenis, dorsal hood deformity
How does pneumococcal cause HUS?
Produces Neuroimidase > T cell attack
Direct Coombs test +
Treat with Abx
Pitfalls of GFR
screwed by tubules & more secreted as GFR falls (inaccurate, overestimates function)
creatnine doesn’t rise until <50% function
actions prostaglandins
dilate afferent arteriole
actions caffeine
dilates afferent arteriole
actions calcium channel blockers
increase GFR > diuresis
what is the strongest markers for chronic kidney disease?
proteinuria
Indications for biopsy with Post Strep GN
Cr elevated at 6 weeks
Complement low at 3 weeks
Proteinuria ongoing at 6 weeks
How to calculate plasma anion gap
(Na + K) - (Cl + Bicarb)
>14 abnormal
Normal Anion Gap
Addisons
GI losses
RTA
Stones and chance of passage
5mm will pass
5-7mm 50% pass
7mm need to be removed
what rise in creatnine is considered acceptable in chronic renal failure treated with ACEinhibitors
20-25%
in obstructive uropathy what correlates with prognosis
Creatnine at 12 months
