Renal and Urology Flashcards
AKI
Criteria?
1) Rise in creatinine of > 25 umol/L in 48hrs
2) Rise in creatinine of >50% in 7 days
3) Urine output of <0.5ml/kg/hr for >6hrs
AKI
Stages?
STAGE 1
- >1.5-1.9x baseline OR <0.5ml/kg/hr for 6-12hrs
STAGE 2
- >2.0-2.9x baseline OR <05ml/kg/hr for 12+hrs
STAGE 3
- 3x baseline or >353umol/L OR <0.3ml/kg/hr for 24hrs OR anuria for >12hrs
AKI
Risk factors?
HANDS C
Heart failure / Hypovolaemia/ Hx of AKI Age >65 Nephrotoxic drugs (NSAIDs/ ACEi) Diabetes Sepsis
CKD/ CLD / contrast agents
AKI
What is Acute Tubular Necrosis?
How does Necrosis occur?
damage and death (necrosis) of the epithelial cells of the renal tubules and most common cause of AKI
Necrosis occurs due to ischaemia or toxins (drugs)
AKI
Pathognomonic finding of ATN?
“Muddy brown casts” found on urinalysis
AKI
How does ATN cause a reduction in eGFR?
Reduced blood supply
AND
dead cells slough off into lumen causing further obstruction
AKI
Pre-renal causes?
Secondary to renal hypoperfusion
- reduced circulating volume (e.g. hypovolaemia)
- reduced cardiac output (e.g. cardiac failure),
- systemic vasodilatation (e.g. sepsis)
- arteriolar changes (e.g. secondary to ACE-inhibitor or NSAID use)
AKI
Intrinsic causes?
(structural damage)
Glomerulonephritis
ATN and Interstitial Nephritis
Rhabdomyolysis
AKI
Post-renal causes?
Obstructive causes (10%)
- Renal stones
- Prostatitis/ cancer / BPH
- Urinary stones
AKI
Investigations?
Urinalysis - Infection (leucocytes), glucose, protein, blood
Ultrasound - if looking for obstruction
AKI
Clinical features?
Pre-renal - dehydration and hypovolaemia or hypervolaemia for cardiac failure (oedema etc)
Intrinsic - Nephrotic / nephritic syndromes
Post renal- loin to groin pain, haematuria, N+V, LUTS
AKI
Clinical features of Acute Interstitial Nephritis and most common cause?
drugs are the most common cause, particularly antibiotics - penicillin / rifampicin
NSAIDs
allopurinol
furosemide
Features - fever, rash, arthralgia
eosinophilia
AKI
Management?
RENAL DRS 26
Record baseline creatinine Exclude Obstruction (US) Nephrotoxic drugs stopped Assess and correct fluids and electrolytes Losses recorded +/- cathether
Dipstick (blood/protein/infection/glucose)
Review meds
Screen
26 creatinine rise for AKI diagnosis
HYPERKALAEMIA
Causes?
CKD
Rhabdomyolysis
AKI / Addison’s
Metabolic Acidosis
drugs*: potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, heparin
HYPERKALAEMIA
Signs on ECG and cardiac complications?
- Tall T
- Absent P
- Broad QRS
- Sinusoidal wave pattern
COMPLICATIONS - VF / arrhythmias
HYPERKALAEMIA
Management?
Cardiac protection = IV calcium gluconate
Shift extracellular K+ intracellular =
• Combined insulin/dextrose infusion
• Nebulised salbutamol
Removal of potassium from body =
• Calcium resonium (orally or enema)
• Loop diuretics
• Dialysis
Causes of Hydronephrosis?
Various obstructions e.g
Unilateral - calculi, ureteric obstruction and tumours
Bilateral - stenosis of urethra/ prostatic enlargement
RHABDOMYOLYSIS
Classic presentation?
Patient fell and prolonged seizure found to have AKI
RHABDOMYOLYSIS
What does muscle cell apoptosis release?
Myoglobin
Potassium
Phosphate
Creatine Kinase
ALL filtered by kidney and myoglobin TOXIC to kidney = AKI
RHABDOMYOLYSIS
Investigations?
Raised CK
Myoglobinuria (red-brown urine)
U+E (AKI and hyperkalaemia)
ECG (hyperkalaemia)
RHABDOMYOLYSIS
Causes?
CCSSEE
Crush injury Collapse Seizure Statin + Clarithromycin Ecstasy excessive exercise
RHABDOMYOLYSIS
Management?
IV fluids
IV Sodium bicarbonate (make kidneys more alkaline)
IV Mannitol to increase GFR and reduce oedema
Triad of Haemolytic Uraemic Syndrome?
AKI
haemolytic Anaemia
thrombocytopenia
Common cause of HUS?
classically Shiga toxin-producing Escherichia coli (STEC) 0157:H7 (90%)
(secondary cause)