Renal Flashcards
Red blood cell casts?
Glomerulonephritis
Renal ischaemia and infarction
White blood cell casts?
Acute pyelonephritis
Interstitial nephritis
Granular (muddy-brown) casts?
Acute tubular necrosis
Hyaline casts?
Common, non-specific
Vigorous exercise, dehydration
Epithelial casts?
Acute tubular necrosis
Waxy casts?
Advanced chronic kidney disease
Fatty casts?
Nephrotic syndrome
What causes ATN?
Acute tubular necrosis causes: Ischaemic - Hypovolaemic shock - Sepsis Nephrotoxic - drugs - pigment nephropathy
What is pigment nephropathy?
Toxic action of heme-containing pigment on kidneys.
This can be from myoglobin or haemoglobin
i.e. rhabdomyolysis or intravascular haemolysis
Leads to ATN
CKD Stages in terms of eGFR?
eGFR measured inmL/min/1.73m^2
Stage 1 = =>90 Stage 2 = 60-90 mild Stage 3a = 30-45 mild/moderate Stage 3b = 45-60 moderate/sever Stage 4 = 15-30 severe Stage 5 = <15 (Kidney failure)
Who should be offered testing for CKD, and what testing?
People are at risk if they have:
- Diabetes
- Cardiovascular disease
- HTN
- AKI
Tests:
- eGFRcreatinine
- ACR (albumin:creatinine ratio)
What is ACR and why useful in CKD?
Albumin:creatinine ratio Useful as the higher it is, the worse CKD <3 normal 3-30 moderate 30+ severe
Combined with eGFR, to determine G and A stage of CKD
Aim for blood pressure ranges in CKD?
<140/90
If they have diabetes or ACR>70
then <130/80
How to treat HTN in CKD?
ACE or ARBs
NOT aldosterone antagonists
Take eGFR readings before starting, and 1-2 weeks after starting
Who should be investigated for AKI?
Acutely unwell and one of:
- CKD
- Heart failure
- Liver disease
- Diabetes
- Hx of AKI
- oliguria
- hypovolaemia
- sepsis
- nephrotoxic drugs
- recent use of iodinated contrast agents
- > 65
Nephrotoxic drugs?
NSAIDs Aminoglycosides ARBs ACEi Diuretics
Diagnosis of AKI if?
If:
- Inc in creatinine of 26micromol/L in 48 hrs
- Inc in creatinine of 50% in 7 days (25% in kids and young people)
- Dec in urine output <0.5ml/kg/hr for 6 hrs (8 in young)
Stages in AKI?
Stage 1
Creatinine:
50-99% rise in 7 days OR >26 micromol/L rise in 48hrs Urine output:
<0.5ml/kg/hr for >6hrs
Stage 2 Creatinine: 100-199% rise in 7 days OR 2-2.9 X baseline rise in 7 days Urine Output: <0.5ml/kg/hr for >12hrs
Stage 3: Creatinine: 200% or more rise in 7 days Urine Output: <0.3ml/kg/hr for >24hrs Anuria >24hrs
Life threatening complications of AKI?
Acute pulmonary oedema
Metabolic acidosis
Hyperkalaemia
Treating hyperkalaemia steps?
- If hyperkalaemia and ECG changes - IV calcium gluconate
2a. If hyperkalaemia >6.5 - nebulised salbutamol
2b. If hyperkalaemia 6-6.5 - IV insulin-glucose (dextrose)
What produces renin?
Juxtaglomerular apparatus -
synthesised as prorenin - 50-90% of circulating renin
Some is cleaved and stored as renin
Renin released controlled by?
Pressure changes in afferent arteriole
Sympathetic tone
Chloride and osmotic conc. in distal tubule
Local prostaglandin and nitric oxide release
Angiotensin II does what?
Systemic vasoconstriction
Sodium & water retention
Thus increase blood pressure
Why is Vitamin D affected by kidney disease?
Kidneys produce enzyme that activates cholecalciferol (vit D).
NB vitamin D increases calcium uptake, so without it, poor bone mineralization
