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.
