Kidney pathology Flashcards
What are the causes of raised urea?
1) Impaired GFR
2) High protein meal
3) GI bleed
4) Catabolic states (breaking down tissue)
5) Dehydration
What causes reduced serum urea?
1) Low protein diet
2) Starvation
3) Liver disease
4) Pregnancy (due to higher blood volume)
5) SIADH (dilution)
What are the causes of raised creatinine?
Impaired GFR High muscle mass Acute muscle damage Diet Exercise Ketones (acetoacetate= a false positive result)
What are the causes of low creatinine?
Small muscle mass
Pregnancy
SIADH
Excess bilirubin
What parameters are used to calculate eGFR?
Serum creatinine
Age
Sex
What biochemical abnormalities would you see in CKD?
Increased urea and creatinine Impaired excretion of sodium and water Decreased bicarbonate (acidosis) Increased serum potassium Decreased calcium PTH increase (due to low Ca) Mg increase Phosphate increase
How do we categorise the causes of AKI?
Pre-renal (due to decreased renal blood flow)
Renal (intrinsic damage)
Post-renal (obstruction)
What biochmical abnormalities are seen in AKI
Decreased sodium, bicarb and calcium.
Increased K, creatinine, phosphate, Mg, H+, urea, urate
What is a clinically significant PCR (protein creatinine ratio) in non-diabetics?
> 50 mg/mmol
What is a clinically significant ACR (albumin creatinine ratio) in non-diabetics and what is it in diabetics?
> 30mg/mmol in non-diabetics
> 3mg/mmol in diabetics
What is the urine protein level in nephrotic syndrome?
> 3.5g/24hrs (>350mg/mmol)
Name some features of nephrotic syndrome?
Proteinuria
High cholesterol and triglycerides due to increased synthesis in the liver
Oedema
Sodium and water retention
What are the three cell types in the glomerulus?
Epithelial (visceral and parietal)
Endothelial
Mesangial
What is the most common cause of nephrotic syndrome in a child?
Minimal change disease
What are the causes of nephrotic syndrome in an adult?
Primary membranous nephropathy, secondary membranous nephropathy (infection, malignancy), diabetic glomerulopathy, sclerosing nephropathy.
What is a common rheumatological cause of IgA disease?
SLE
Causes of haematuria
IgA disease (primary or secondary) Thin glomerular basement membrane disease Post infectious (e.g. streptococcal)
Causes of haematuria
Masses e.g. cancers or urinary tract Acute pyelonephritis Cystitis Renal stones IgA disease (primary or secondary) Thin glomerular basement membrane disease Post infectious glomerulonephritis (e.g. streptococcal) Vasculitis
How do we manage CKD?
Dialysis.
May eventually need transplant.
What is a complicated UTI?
A UTI where there are:
1) functional or structural abnormalities
2) factors that predispose to persistent or recurrent infection or treatment failure.
What are the most common organisms causing UTI?
Escherichia coli
Staphylococcus saprophyticus
Proteus mirabilis
Less common= klebsiella species, other staphs, pseudomonas aeruginosa, mycobacterium TB, candida species, viruses (adenovirus)
What symptoms are likely present in pyelonephritis but not cystitis?
Fever
flank pain and tenderness
How do we treat uncomplicated UTI in adults?
Trimethoprim PO
or Nitrofurantoin PO
Duration= 3 days in women, 5 days in men
How do we treat lower UTI in pregmancy?
Cefadroxil PO Nitrofurantoin PO (1st trimester) Trimethoprim PO (2nd and 3rd trimester)
Duration = 7 days.
How do we treat pyelonephritis in pregnancy?
Cefuroxime IV
Switch to Amox or Ciprofloxacin PO
Duration = 7 days for Cipro, 14 days for all other
Add Gentamicin if hypotensive or shock
How do we treat pyelonephritis?
Cefuroxime IV
Cipro PO
Duration = 7d for cipro, 10d for others.
Add Gentamicin if hypotensive or shock
What are the most useful tests for AKI?
Renal ultrasound and urine dipstick
What are the main causes of AKI
S- sepsis and hypoperfusion
T- toxins
O- obstruction
P- parenchymal renal disease
What is the single commonest cause of end stage renal failure?
Type 2 diabetes
What vertebral levels are the kidneys found at?
T12-L3
What are the causes of polyuria?
Polydipsia (Intake increased by 3L/day)
Solute diuresis (hyperglycemia with glycosuria)
Diabetes insipidus
CKD
What is nocturia caused by?
Drinking before bed. Prostatic enlargement (men over 50)
What are the main causes of oliguria?
AKI
Urinary tract obstruction
Physiological- hypotension and hypovolaemia
What can cause sterile pyuria (pus cells but not bacterial infection)?
Partially treated UTI Urinary tract TB Calculi Bladder tumour Papillary necrosis Tubulointerstitial nephritis.
What are the four major glomerular syndromes?
1) Nephrotic syndrome
2) Acute glomerulonephritis (acute nephritic syndrome)
3) Rapidly progressive glomerulonephritis
4) Asymptomatic haematuria, proteinuria, or both.
