Kidney Disease Flashcards
how can kidney disease present
Asymptomatic Loin Pain / Urinary Symptoms Haematuria Proteinuria - urine appears frothy Hypertension Acute Kidney Injury Chronic Kidney Disease Nephrotic Syndrome Nephritic Syndrome
function of the kidney
excretion of nitrogenous waste (urea) fluid balance electrolyte balance acid-base balance vitamin d metabolism / phosphate excretion production of erytropoietin drug excretion barrier to loss of proteins
what can errors in fluid balance cause
oedema
what does a failure in excretion of nitrogenous waste (urea) cause
Uraemia
(pericarditis/ encepalopathy/ neuropathy/ asterixis/ gastritis)
late stage kidney disease
pleural rub heard - emergency dialysis needed
what can errors in electrolyte balance cause
Hyperkalaemia & arrythmia
what can errors in acid-base balance cause
Metabolic Acidosis & Kussmaul’s Respiration
what can errors in vitamin d metabolism / phosphate excretion balance cause
Renal Bone Disease & Vascular Calcification
what can errors in production of erytropoietin cause
anaemia
what can errors in barrier to loss of proteins cause
Proteinuria & Nephrotic Syndrome
PC - asymptomatic but why could they still be picked up
dipstix microscopic haematuria &/or proteinuria
reduced estimated GFR on biochemical screen
raised BP
incidental findings on abdominal imaging
screening because of family history
PC - systemic
related to disease
eg: diabetes mellitus, connective tissue disorder, vascular disease
related to loss of kidney function
e.g.: uraemic, fluid retention, anaemia, bone pain
PC - local/renal
eg loin/abdo pain, macroscopic haematuria, UTI
systemic enquiry Q’s
- appetite & weight loss
- nausea & vomiting
- dyspepsia
- dyspnoea
- urinary symptoms eg frequency, urgency, hesitancy, polyuria & nocturia
- joint pains & arthralgia
- skin rashes
PMH
kidney disease, DM, vascular disease, surgery, TB, rheumatological
FH
renal disease, hypertension
SH
smoking, alcohol, occupation, carers
Drugs
ACE-I, ARB, diuretics (thiazide, loop, potassium sparing)
NSAIDS - very harmful to kidneys (decrease GFR)
Antibiotics: gentamicin (nephrotoxic), trimethoprim, penicillins
Proton pump inhibitors
what is accelerated hypertension
a medical emergency diastolic BP >120 mmHg papilloedema seen end-organ decompensation eg: encephalopathy, fits, cardiac failure, acute renal failure
when is leukonychia seen
(white patches on nails)
associated with acute illness and profound hypoalbuminemia
when is gouty Tophus seen
kidney disease
non blanching skin rash, very red
Could be:
Vasculitic Skin Rash
» Acute Glomerulonephritis
Henoch-Schonlein Purpura - HSP
form of vasculitis - IgA mediated
seen on extensor surface of skin and buttock
what are the classifications of urine protein
24 hour urine collection (normal 3 G/Day)
sign of hyperkalaemia on ECG
Tall Tented T waves
what is definition of acute kidney injury
Decline in GFR over hours / days / weeks
- with or without oliguria (
what is the triad of nephrotic syndrome
Proteinuria > 3 g/day
(mostly albumin, also globulins)
Hypoalbuminaemia
Oedema - esp peri-orbital oedema but not pulmonary oedema
what is often associated with nephrotic syndromes
Hypercholesterolaemia
Can have normal renal function
what happens in Nephritic syndrome
1-Acute Kidney Injury 2-Oliguria 3-causes Oedema/ Fluid retention 4-leads to Hypertension 5-Active urinary sediment - RBC’s, RBC & Granular Casts, proteinuria
definition of CKD
Reduced GFR and/or evidence of kidney damage
Must be chronic (!) – CKD can’t be diagnosed from one measurement
how is GFR assessed
Estimation by creatinine clearance
Can be estimated from serum creatinine, age, sex and race
what is creatinine and how can this influence GFR
product of muscle breakdown; muscular people produce more creatinine giving inaccurate result
what can cause an inaccurate eGFR
Over-estimates GFR if muscle mass is low
Under-estimates if muscle mass high
Only valid if serum creatinine is stable
what are the stages of CKD
Stage 1 – GFR >90ml/min, with evidence of kidney damage
Stage 2 – GFR 60-90ml/min, with evidence of kidney damage
Stage 3 – GFR 30-60ml/min
(3A – 45-60ml/min; 3B – 30-44ml/min)
Stage 4 – GFR 15-30ml/min
Stage 5 – GFR
what does CKD increase risk of
increases CV risk
who is likely to increase in stages of CKD
Patients with proteinuria more likely to progress; More proteinuria – faster progression
Younger patients have longer to progress – more likely to reach stage 5
what are common causes of CKD
Diabetes - commonest cause Hypertension Vascular disease Chronic glomerulonephritis Reflux nephropathy Polycystic kidneys Cause not known
when do symptoms of CKD appear
Symptoms due to reduced GFR don’t occur until late – GFR
Sx of CKD
Non-specific – tiredness, poor appetite, itch, sleep disturbance
Impaired urinary concentrating ability – symptoms may occur earlier - nocturia
Mx of CKD
Reduce cardiovascular risk
Identify and treat complications of CKD
Prepare for renal replacement therapy
how can the progression of CKD be slowed down
Reduce Proteinuria + Control blood pressure
ACE-inhibitors and ARB reduce BP and proteinuria
Spironolactone
Stop smoking
Good glycaemic in DM
Statins
what can happen when you start a patient on an ACE-i and is a worrying side effect and how is it managed
initial fall in GFR
hyperkalaemia - patient given blood test 7-10 days after starting ACE-i to check for hyperkalaemia
complications of CKD
Anaemia
Bone disease»_space; Secondary Hyperparathyroidism
how is anaemia caused in CKD
Production of Erythropoietin produced by the kidneys declines
Tx of anaemia of CKD
1st line - IV iron
2nd line - Erythropoietin given subcutaneously
why are the bone problems in CKD
Vitamin D hydroxylated in the kidney - Impaired in CKD
Leads to reduced calcium absorption, leading to secondary hyperparathyroidism
biochemistry results in CKD
In advanced CKD, serum phosphate rises – also increases PTH secretion
how is normal serum calcium maintained in secondary hyperparathyroidism
at the expense of the bones
how can secondary hyperparathyroidism progress
1 -Hyperplasia of all glands
2 -One gland may become autonomous – PTH secretion not suppressed by calcium
3 - tertiary hyperparathyroidism
what can tertiary hyperparathyroidism lead to
hypercalcaemia
what does high phosphate and high calcium indicate
vascular calcification
|»_space; stiff blood vessels + heart valves stiff
Tx of bone disease in CKD
Alfacalcidol – hydroxylated vitamin D – doesn’t need activation by kidneys
Phosphate – advice from dietician on intake
Tx for end-stage renal failure
- Haemodialysis
- Peritoneal dialysis
- Transplantation
- Conservative management
when is dialysis considered
when GFR about 20ml/min (earlier if progressing fast)
what needs to be done in haemodialysis
plan vascular access Arteriovenous fistula (AVF) is best from of access
AVF needs 6 weeks to mature after formation
what needs to be done in peritoneal dialysis
Operation needed to insert catheter
Catheter can be used after 1-2 weeks
when is a patient referred to a vascular surgeon to create a AVF for haemodialysis
when GFR about 15ml/min
when can patients go onto the transplant list
Patients can be listed for cadaveric transplantation when within 6 months of dialysis
Patient also needs to be fit enough
when is conservative management considered
in the elderly with multiple co-morbidities
symptom control/palliative care
definition of Acute kidney injury
An abrupt (26.4µmol/l
OR increase in creatinine by >50%
OR a reduction in UO
pre-renal cause of AKI
Hypovolaemia
e.g. Haemorrhage, Volume depletion (e.g. D&V, burns)
Hypotension
e.g. Cardiogenic shock
Renal Hypoperfusion
e.g. NSAIDs / COX-2, ACEi / ARBs
what is oliguria
very little urine output
is pre-renal AKI volume depletion reversible?
yes
what happens when there is decreased renal perfusion
increased renin
increased angiotensin II
» GFR maintained
how does a ACEi affect renal perfusion
not as much angiotensin II produced so a slight reduced of GFR
what can ACEi causes occasionally and how does this happen
Acute renal failure
ACE inhibitors reduce Angiotensin II. Angiotension II mediates arteriolar vasoconstriction therefore increasing GFR. ACE I therefore can cause a fall in GFR by causing effferent arteriolar vasodilation.
pathophysiology of pre-renal AKI
1 - Volume depletion and/or Sepsis 2 - Decreased Effective Intravascular Volume 3 - Increased ADH & Aldosterone 4 - Oliguria 5 - AKI
what does untreated Pre Renal AKI lead to
Acute tubular necrosis
what is Acute tubular necrosis
decreased renal perfusion
Tx for Pre Renal AKI
Assess for hydration
- BP, HR, Oedema, Pulmonary oedema
Crystalloid (0.9% NaCl) or Colloid (Gelofusin) - for hypovolaemia
Causes of Renal AKI
Vascular
- vasculitis, renovascular disease
Glomerular:
- Glomerulonephritis
Interstitial Nephritis:
Drugs, Infection (TB), Systemic (sarcoid)
Tubular Injury:
Ischaemia—prolonged renal hypoperfusion
Drugs (gentamicin)
Rhabdomyolysis
Sx of AKI
- Anorexia, weight loss, fatigue, lethargy
- Nausea & Vomiting
- Itch
- Fluid overload e.g. Oedema, SOB
Signs of AKI
Fluid overload incl HTN, Oedema, Pul oedema, effusions (pleural & pulmonary)
Uraemia incl itch, pericarditis
Oliguria
Ix of AKI
U&Es
- Marker of renal function (Na, K, Ur, Cr)
FBC
Urinalysis
USS- Obstruction? Size?
Immunology
- ANA (SLE), ANCA (Vasculitis), GBM (Goodpastures)
Protein electrophoresis & BJP
- myeloma? (everyone over 50yrs)
what are indications for a renal biopsy
Suspected rapidly progressive GN
Positive Immunology & AKI
Tx of AKI
Establish good perfusion pressure
- Fluid resuscitate
- Once fluid resuscitated, if still not achieving an adequate BP inotropes/vasopressors
Treat underlying cause
- Antibiotics if sepsis
Stop nephrotoxics
Dialysis if remains anuric & uraemia
Can require urgent dialysis
what are life threatening complications of AKI
Hyperkalaemia Fluid Overload (Pulmonary oedema) Severe Acidosis (pH 40)
what causes post renal AKI
AKI due to obstruction of urine flow leading to back pressure (hydronephrosis) and thus loss of concentrating ability
Causes: Stones, Cancers, Strictures, Extrinsic Pressure
Tx of post renal AKI
Relieve obstruction
- Catheter
- Nephrostomy
Refer to urology if ureteric stenting required
what is classified as hyperkalaemia
Hyperkalaemia = >5.5
Life threatening hyperkalaemia = >6.5
how is hyperkalaemia assessed
ECG
Muscle Weakness
Tx of hyperkalaemia
- 10mls 10% calcium gluconate
- Insulin (actrapid 10units) with 50mls 50% dextrose (30 mins)
- Salbutamol Nebs (90 mins)
urgent indications for hemodialysis
Hyperkalaemia
>7 or >6.5 unresponsive to medical therapy
Severe Acidosis
pH 40, pericardial rub/effusion