Renal Flashcards
Pre-renal causes of AKI
Reduced perfusion as a result of either circulatory changes or a reduction in glomerulus perfusion pressure leading to a reduced eGFR:
Hypovolaemia (haemorrhage, dehydration, burns etc.)
Hypotension (shock)
Fluid overload (cirrhosis, CCF, nephrotic syndrome)
Reduced cardiac output (shock, MI, arrhythmia, CCF)
Vascular changes (renal stenosis or thrombosis)
Drugs such as ACE-I’s and NSAIDS
Renal (Intrinsic) causes of AKI
Anything which impacts the parenchyma of the kidneys and may occur as a result of chronic pre or post renal pathologies:
Glomerular damage (glomerulonephritis, IgA nephropathy, thrombosis, uraemic syndrome
Acute interstitial nephritis
Acute tubular necrosis
Vasculitis
Post-renal causes of AKI
Anything that obstructs urine flow below level of renal calyx:
Stones Clots Malignancy BPH Strictures Retroperitoneal fibrosis
Criteria for AKI stage 1
Rise in creatinine of at least 26 mol/L in 48 hours
OR
Creatinine rise to 50%+ of baseline in 7 days
OR
Urine output < 0.5ml/Kg/Hr for 6+ hours
Criteria for AKI stage 2
Creatinine 2x baseline
OR
Urine output < 0.5ml/Kg/Hr for 12+ hours
Criteria for AKI stage 3
Creatinine 3x baseline OR Rise of 1.5 baseline to at least 355 micromol/L OR Urine output < 0.3ml/Kg/Hr for 24 hours OR Anuria for 12+ hours
Complications of AKI
Uraemia Hyperphosphataemia Hyperkalaemia Prolonged chronic kidney disease Metabolic acidosis Electrolyte imbalances
Investigating AKI
U&E's with creatinine FBC CRP LFTs - hepatorenal syndrome? Clotting Creatine Kinase - rhabdomyolysis? VBG
Urine dip and cultures
Monitor urine output
Fluid challenge
ECG especially if potassium deranged
Renal US - if obstruction suspected or no cause obvious
CT/MRI is US suggests obstruction or not cause obvious
CKD symptoms
Fatigue Nocturia Hypertension Hameaturia and/or proteinuria Nausea and vomiting Itching Breathlessness
Late stages: Seizures Reduced GCS Kussmaul's respiration Muscle twitching
CKD Complications
Anaemia from erythropoietin deficiency
Renal osteodystrophy due to PTH rising in response to hypokalaemia and hyperphosphataemia
Vitamin D deficiency
Cardiovascular disease
Protein malnutrition
Metabolic Acidosis
Oedema
Hyperkalaemia
CKD Stages + eGFR + Symptoms
Stage 1 - Damage but eGFR normal - Asymptomatic
Stage 2 - Damage with eGFR 60-89 - Asymptomatic
Stage 3a - eGFR 45-59 - Can be asymptomatic
Stage 3b - eGFR 30-44 - Anaemia
Stage 4 - eGFR 15-29 - Electrolyte disturbances
Stage 5 - eGFR < 15 - Significant complications
Causes of CKD
Diabetes Interstitial disease Glomerular disease Hypertension Systemic inflammatory disease Congenital conditions Renal artery stenosis
Treating CKD
Stage 1-2 with no uraemia
1) ACE-I/ARB or non-dihyrdopyridine CCB
2) Statin
Additional HTN control if needed
Glycaemic control if needed
Stage 3-4 with no uraemia
Same as above + education on renal replacement (e.g. dialysis, transplantation)
Stage 5 OR any stage with uraemia
1) Dialysis
2) Kidney Transplant
If anaemic: Erythropoietin stimulating agent, Fe
If hyperparathyroidism: phosphate binder, calcium mimetic, vitamin D
Investigating CKD
eGFR - stage of CKD
U&E’s - electrolytes, especially K+
ECG - arrhythmia etc.
Bone profile - hyperparathyroidism, hypocalcaemia, hypoalbuminaemia
FBC - anaemia
Urinalysis - protein and blood in urine
HbA1c - glucose control
Lipids - lipid control
Renal US +/- Bx
ADPKD Symptoms
Hypertension Abdominal/flank pain Haematuria Palpable kidneys Hepatomegaly Headache Heart murmur Hernia
