Nephrology Flashcards
Nerve supply of Urinary Bladder
Sympathetic: T10- L2 = Detrusor muscle relaxation + Bladder neck contraction
Parasympathetic: S2- S4= Detrusor muscle contraction + inhibit internal sphincter
Somatic: S2- S4= External Sphincter control
GFR measured Directly by
- Inulin
- EDTA
Though it’s not performed routinely usually reserved for special circumstances such as assessment of kidney function in potential live kidney donor
What are the factors affecting GFR
- S. Creatinine
- Age
- Gender
- Ethnicity
CAGE
GFR over- estimate in?
Patient with low muscle mass e.g. cachexia, amputees
eGFR is not valid in
- Assessing AKI
- Under 18s
- During pregnancy
What are the dynamic tests of tubular function?
- Concentrating ability
- Ability to excrete water load
- Ability to excrete acid
- Calculation of fractional calcium, phosphate, sodium
Which test is used to differentiate between pre-renal uraemia (volume depletion) and ATN in AKI?
FENa typically less than 1.0 in volume depletion and more than 1.0 in ATN
Feature of CKD + raised ALP dx?
Renal Osteodystrophy
Urea level increased in?
CKD
High protein intake
GI Haemorrhage
Catabolic State
Urea level decreased in
Chronic liver disease
Anorexia
Malnourished patients
Electrolyte findings on CKD
- ↓ calcium
- ↑ Phosphate
- ↑ PTH
- ↓ 1,25 dihydroxyvitamin D
- ↑ ALP
Up To which level of GFR the patient can be asymptomatic?
45
What are the USG criteria of CKD
- Increased Ecogenicity
- Corticomedullary differentiation will be poor
- Reduced size
Dialysis should be initiated when eGFR falls below
10
First sign of CKD shows when eGFR
45-59 at stage 3B
First symptoms arise on CKD
GFR < 20
Gold standard investigation for upper urinary tract pathology
CTU ( computed tomography urography)
Method of choice for investigating renal stones
CT KUB
Indication of renal arteriography
- RAS
- Haemorrhage following trauma
Radionuclide agents and their function
TcMAG3 → perfusion+ obstruction
DPTA → perfusion + GFR measurement
DMSA → Morphology + individual function of each kidney
Risk factor for radiological investigation
- Pre-existing renal impairment (eGFR>45)
- DM
- Myeloma
- Ionic contrast media
- Repetitive dosing in short time span
Indication of renal biopsy
- AKI or CKD with uncertain etiology
- Nephrotic syndrome or glomerular proteinuria in adults
- Nephrotic syndrome in children that has atypical features or does not respond to treatment
- Nephritic syndrome
- Renal Transplant dysfunction
What are the contraindications for Renal biopsy?
- Disordered coagulation or thrombocytopenia
- Uncontrolled hypertension
- Kidney less than 60% of predicted size
- Solitary kidney
Causes of Anuria
Urinary Obstruction
1. Urinary retention due to prostatic enlargement, urethral stenosis, Bladder tumor
2. Bilateral ureteric obstruction due to fibrosis, stone, cancer, radiation injury
3. Bilateral renal stones ( usually staghorn calculi)
4. Massive crystalluria
Lack of renal perfusion
1. Aortic dissection involving renal arteries
2. Severe ATN
3. Severe functional hypoperfusion
Rapidly Progressing Glomerulonephritis
1. Anti-GBM Disease
2. Severe ANCA Vasculitis
What is the most common cause of dysuria?
UTI
Causes of non pitting oedema
- Lymphatic obstruction
- Hypothyroidism
- Systemic sclerosis
Causes of visible haematuria
- Malignancy
- Infection
- Stone
- IgA nephropathy
What is the investigation of choice in visible haematuria?
Cystoscopy
Features of nephritic syndrome
- Haematuria
- Hypertension
- Oliguria
- Fluid retention
- Reduced renal function
What are the causes of painless haematuria?
- Glomerulonephritis especially nephritic presentation (most common)
- Interstitial nephritis
- Vasculitis
- BEP
- Prostate Cancer
- Tumor in urogenital tract
What is the normal level of protein in urine?
0-150 mg
What is the protein that is derived from tubular cells in healthy individuals? And which gene encodes it?
Tamm Horsfall protein (uromodulin) encoded by the UMOD gene
What is the Rx of orthostatic proteinuria?
It is a benign condition that does not require any treatment
What is the best time for taking a sample of proteinuria?
Early morning sample
What are rapidly progressing glomerulonephritis?
- Post infectious glomerulonephritis
- Ani- GBM Disease
- Lupus nephritis
- Small vessel vasculitis
The most sensitive marker of glomerular pathology is-
Albuminuria
Causes of transient proteinuria
- Fever
- UTI
- Vigorous Exercise
- Heart failure
What are the features of nephrotic syndrome?
- Overt proteinuria
- Hypoalbuminaemia
- Oedema and generalised fluid retention
- Possible intravascular volume depletion with hypotension, or intravascular expansion with hypertension
The most common cause of nephrotic syndrome in children
Minimal Change Disease
What are the nephrito-nephritic presentation
- SLE
- IgA nephropathy
- MCGN/ MPGN
- FCGS
- Diabetic Nephropathy
What is the early and universal feature of nephrotic syndrome?
Renal sodium retention
What is the mechanism of nephrotic syndrome?
- Injury to podocytes
- Changed architecture
- Scarring
- Deposition of matrix or other elements (amyloid)
What is the mechanism of nephritic syndrome?
- Inflammation
- Reactive cell proliferation
- Breaks in GBM
- Crescent formation
Indication of renal biopsy according protein quantification in urine
- More than 1 gm protein excreted in urine within 24 hours
- ACR is 70 - 300
- PCR is 100 - 350
This indicates glomerular disease more likely
What are the features of ACR
- Highly sensitive
- More expensive
- Can detect the early stage of diabetic nephropathy
- Helpful to identify the type of protein in urine
Bence jones protein found in
- AL amyloidosis
- Plasma cell / B-cell Dyscrasias
- Myeloma
Hallmark of glomerular disease
Proteinuria
What are the consequences of nephrotic syndrome?
- Hypoalbuminaemia
- Avid sodium retention
- Hypercholesterolaemia
- Hypercoagulability
- Infection
Poor prognostic feature in nephrotic syndrome
- Hypertension
- Male sex
- Persistent and severe proteinuria
- Elevated creatinine at the time of presentation
- Rapid rate of decline in renal function
- Tubulo-interstitial fibrosis observed on renal biopsy