Renal & Urology Flashcards
how do the kidneys sense blood pressure?
macula densa senses the sodium concentration of fluid in the tubule which is an indicator of blood pressure
Name the 2 compounds that can be used to assess eGFR
Inulin and CK
Explain where creatinine comes from
It is a muscle breakdown product
How is the anion gap calculated?
(Na+ + K+) – (Cl- + HCO3-) = Anion gap
What is a normal anion gap?
10-18
List the causes of a raised anion gap metabolic acidosis
- M – Methanol
- U – Uraemia
- D – Diabetic ketoacidosis, starvation and alcoholic ketoacidosis
- P – Paracetamol use (chronic)
- I – Isoniazid
- L – Lactic acidosis & shock
- E – Ethylene Glycol
- S – Salicylates
Which must be corrected first -calcium or phosphate?
Always correct phosphate before calcium
What 3 criteria can be used to diagnose AKI
- 25 micromol/L rise in creatinine in 48 hours
- 50% rise in creatinine in 7 days
- <0.5ml/kg/hour urine output for 6 hours
Name the pre-renal causes of AKI
Cardiac failure
Haemorrhage
Sepsis
Vomiting and diarrhoea
Name the renal causes of AKI
Acute tubular necrosis
Glomerulonephritis
Vasculitis
Radiocontrast
Myeloma
Rhabdomyolysis
Drugs (e.g. NSAIDs and gentamycin)
Name the post-renal causes of AKI
Tumours
Prostate disease
Stones
Strictures
What are the immediately dangerous consequences of AKI?
- Acidosis
- Electrolyte imbalance
- Intoxication & toxins
- Overload of fluid
- Uraemic complications
(AEIOU)
Name 5 drugs that must be stopped in AKI
- Angiotensin II receptor antagonists
- Aminoglycosides
- ACE inhibitors
- Diuretics
- Metformin (risk of lactic acidosis)
Which drugs should you consider stopping in patients with an AKI due to risk of accumulation and toxicity?
Lithium
Digoxin
Describe the steps involved in treating hyperkalaemia
Stabilise the myocardium (calcium gluconate)
Shift K+ intracellularly (salbutamol and insulin-dextrose)
Remove as much potassium as possible
(Diuresis, Dialysis, Potassium binders)
What is CKD?
Chronic reduction in kidney function over 3 months
What are the two biggest causes of CKD?
Diabetes and hypertension
What pathology within the kidney is caused by chronically high sugar levels?
Glomerulosclerosis
What pathology within the kidney is caused by chronically high blood pressure?
nephrosclerosis
What are the G and A scores for CKD based on?
G = eGFR
A= Albumin:creatinine ratio
How is proteinuria quantified?
Albumin:creatinine ratio
What is the BP target in patients <80 years with CKD?
130/80
Which drugs are used to slow the progression of CKD?
ACE inhibitors, SGLT-2 inhibitors
what additional drug should be stated in all patients with CKD to help prevent cardiovascular complications?
Statin
Why do patients with CKD become anaemic?
Due to lack of erythropoietin
How does the anaemia look in (CKD) - like what do the red blood cells look like?
Normocytic normochromic
What must be treated before erythropoietin can be given?
Iron deficiency
What impact does CKD have on calcium regulation
Causes low vitamin D because the kidneys aren’t able to activate it as well. This leads to low calcium
What is needed for a glomerulonephritis to be classed as nephrotic syndrome?
> 3g protein in the urine within 24 hours
What does nephrotic syndrome mean for the state of the kidney?
indicates that the basement membrane has become so damaged that it is now permeable to the larger protein molecules
How does nephrotic syndrome present?
Frothy urine and oedema
What does nephrotic syndrome predispose patients to?
thrombosis, hypertension and high cholesterol
What are the distinguishing features of IgA nephropathy?
1-2 days after an infection
IgA deposits and mesangial proliferation
What are the distinguishing features of post-infective diffuse proliferative glomerulonephritis?
1-2 weeks after strep (tonsillitis or vitiligo)
Caused by IgG deposits
How is lupus nephritis managed?
Immunosuppressants and corticosteroids
What are the distinguishing features of Granulomatosis with Polyangiitis?
C-ANCA
Nosebleeds
What are the distinguishing features of good pastures?
Anti-GBM
Gomerulonephritis and pulmonary haemorrhage (AKI & Hameoptysis)
20s and 60s
What are the distinguishing features of Cresenteric / rapidly progressing glomerulonephritis?
Glomerular crescents
Acute severe illness
What are the distinguishing features of membranoproliferazive glomerulonephritis?
Patients under 30
Immune complex deposition and mesangial proliferation
What are the distinguishing features of Membranous Glomerulonephritis (IgG)?
Underlying malignancy
IgG deposits
What are the distinguishing features of Minimal change?
Children
Oedema
What are the distinguishing features of Focal segmental glomerulonephritis?
Focal and segmental sclerosis
What are the distinguishing features of diabetic nephropathy?
Hyperglycaemia causes damage to the glomerulus causing the leaking of albumin into the urine
Glomerulosclerosis and interstitial fibrosis also occurs
How is glomerulonephritis diagnosed?
renal biopsy
How is glomerulonephritis managed?
Supportive
Immunosuppression
For nephrotic syndrome:
* Reduce salt
* Loop diuretics
* Manage hypertension
* Heparin to reduce thrombus risk
* Pneumococcal vaccine
* Statins
Which demographic tends to be affected by multiple myeloma?
Elderly
What urine findings might indicate multiple myeloma?
Heavy proteinuria
Bence-jones proteins
What causes damage to the kidneys in multiple myeloma?
Cast nephropathy
How is multiple myeloma managed?
Immunotherapy and steroids
What is acute tubular necrosis?
Damage and death of the epithelial cells of the renal tubules caused by ischaemia or nephrotoxins
Explain the difference between the 4 different types of acute tubular necrosis
Type 1 = distal tubule cannot excrete hydrogen ions
Type 2 = proximal tubule cannot reabsorb hydrogen ions
Type 3 = mix of type 1 & 2
Type 4 = caused by reduced aldosterone
What might you see on urinalysis in a patient with acute tubular necrosis?
Muddy brown casts
How is acute tubular necrosis managed?
Oral bicarbonate
What is acute interstitial nephritis?
An inflammatory reaction in the space between the tubes and the vessels (interstitum) caused by an immune reaction to drugs, infections or autoimmune conditions
what blood test finding is associated with acute interstitial nephritis?
eosinophilia
What is haemolytic uraemia syndrome?
Thrombosis in small blood vessels triggered by shiga toxins from E.coli or shigell
Which demographic is commonly affected by haemolytic uraemia syndrome?
Children following a bout of gastroenteritis
how should haemolytic uraemia syndrome be managed?
Give antibiotics and anti-motility medication (e.g. loperamide)
How is the causative agent in haemolytic uraemia syndrome tested for?
Stool antigen test
What is the inheritance pattern in polycystic kidney disease?
Autosomal dominant
What is the gene and chromosome affected in polycystic kidney disease
PKD1 gene on chromosome 16
What additional complications are those with polycystic kidney disease at risk of?
Liver cysts
Subarachnoid haemorrhage
Mitral regurgitation
What medication can slow the development of cysts in polycystic kidney disease
Tolvaptan
What is the best imaging modality for detecting renal stones?
Non contrast CT KUB
What are most renal stones made from?
Calcium oxalate
Which renal stones don’t show up on X-ray?
uric acid
What are stag horn calculi made from and what produces this compound?
Struvite (made by bacteria)
How are renal stones managed?
How are renal stones prevented?
- High fluids
- Low protein, low salt
- Thiazide diuretics
What is the difference between acute and chronic urinary retention?
Acute = painful inability to void with a palpable and percussible bladder
Chronic = painless, palpable and percussible bladder after voiding
How do alpha blockers (tamsulosin) work?
Causes smooth muscle relaxation
How do 5-alpha reductase inhibitors work (finasteride)?
Blocks the hormone responsible for converting testosterone to its active form. This slows prostatic growth.
What type of cancer is prostate cancer?
Adenocarcinoma
Where in the prostate does cancer most commonly grow?
Peripheral zone
What grading system is used for prostate cancer/
Gleason
name the two most common types of bladder cancer and their causes
Aromatic amines in dye and rubber cause transitional cell carcinoma
Schistosomiasis causes squamous cell carcinoma of bladder
What is the biggest risk factor for bladder cancer?
smoking
what characteristic metastasis is associated with renal cell carcinoma?
Cannon ball lung mets
How is hydronephrosis managed?
Percutaneous nephrostomy or an antegrade ureteric stent
What antibiotic can be used to treat a UTI in pregnancy?
amoxicillin or nitrofurantoin (up to 37 weeks)
How many days should a UTI be treated for in men, pregnant women and women with a complicated UTI?
7 days (and send an MSSU!!)
What is the treatment for an asymptomatic UTI in a catheterised patient?
No treatment
What is the treatment for pyelonephritis?
7-10 days of cefalexin
What is the management for stress incontinence
- Pelvic floor exercises
- Duloxetine (SNRI)
What is the management for urge incontinence
- Bladder retraining
- Oxybutynin (Anti-muscarinic)
What is the difference between nephrogenic and cranial diabetes insipidus?
Nephrogenic = lack of response to ADH.
Cranial =Lack of ADH production.
How can cranial and nephrogenic diabetes insipidus be differentiated?
Water depravation test
How is cranial diabetes insipidus treated?
Desmopressin
How is nephrogenic diabetes insipidus managed?
Conservative
What are the indications for renal replacement therapy?
- A – acidosis
- E- electrolyte abnormalities
- I – intoxication
- O – oedema
- U – uraemia symptoms such as seizures or reduced consciousness
What is the most common osmotic agent for ultrafiltration of fluid in peritoneal dialysis?
Glucose
How long does an AV fistula need to mature before it can be used
4-16 weeks
Which viruses pose a major risk o kidney transplant recipients?
Cytomegalovirus and EBV
What is the standard immunosuppressant regimen following kidney transplant?
- Induction with Basilximab
- Maintenance with Tacrolimus, Mycophenolate and steroids
How are donors and recipients matched for renal transplant?
matched based on the human leukocyte antigen (HLA ) A, B & C on chromosome 6. The closer the match, the less chance of rejection
