Renal Flashcards
What features help distinguish between IgA nephropathy and post-streptococcal glomerulonephritis?
Define acute kidney injury (AKI). What are the severity criteria for AKI?
AKI is an acute decline in the GFR from baseline, with or w/o oliguria/anuria
(BMJ)
Kidney Disease: Improving Global Outcomes (KDIGO) severity criteria
- Stage 1: creatinine x1.5-1.9 baseline or UO <0.5ml/kg/h for >6h
- Stage 2: creatinine x2.0-2.0 baseline or UO <0.5ml/kg/h for >12h
- Stage 3: creatinine x3.0 baseline or UO <0.3ml/kg/h for >24h or anuria for 12h or renal replacement tx
(Passmedicine, BMJ)
Summarise the epidemiology of acute kidney injury (AKI)
~20% inpatients
20-50% ITU pts
Give some strong and weak risk factors for AKI
Stong RFs
- Haemorrhage, sepsis, pancreatitis, surgery, cardiac arrest, dehydration
- PMH: CKD, T2DM, HTN, myeloproliferative dx. connective tissue dx
- DHx: aminoglycosides, NSAIDs, ACE-inhibitors, contrast
Weak RFs
- Lifestyle: drugs, alcohol
- PMH: malignancy, recent blood transfusion, genetic susceptibility
(BMJ)
Define chronic kidney disease (CKD)
>12w of kidney damage (urinary albumin >30mg/day) or impaired kidney function (eGFR <60 ml/min/1.73m^2)
(UpToDate)
How are the stage of chronic kidney disease defined? At which stage is referral to secondary care indicated?
Stage 1: eGFR >90
Stage 2: eGFR 60-89
Stage 3a: eGFR 45-59
Stage 3b: eGFR 30-44
Stage 4: eGFR 15-29
Stage 5 (ESRF): eGFR <15
Only stage 3b+ has to be seen in secondary care
Stage 1/2 only diagnosed if urinalysis or USS kidney suggest disease
What drugs mostly commonly trigger AKI?
Commonly used: CANADA
- Contrast media
- Aminoglycosides (gentamicin, amikacin)
- NSAIDs
- ACE-inhibitors /ARBs
- Diuretics (pre-renal)
- Aciclovir
Rarer: CCC
- cyclosporin, tacrolimus
- carboplatin, cisplatin
- cephalosporins
(remember, metformin is not nephrotoxic, but can worsen AKI)
What are the most common causes of chronic kidney disease?
Most common:
- Diabetic nephropathy (40%)
- Hypertensive nephropathy (30%) and vasculitic (SLE, GwP)
- Glomerulonephritis (focal segmental glomerulosclerosis, lupus nephritis, rapidily progressive GN, membranous GN)
- Polycystic Kidney Disease
- Reflux nephropathy (chronic pyelonephritis, TB)
Other causes:
- Drug toxicity (gold, penicillamine, lithium)
- Neoplastic: RCC, myeloma
- Renal artery stenosis
(path, BMJ)
Identify appropriate investigations for chronic kidney disease (CKD)
Part of examination: BP, urinalysis
Confirm diagnosis:
- Bloods: Igs + serum protein electrophoresis (myeloma), dsDNA, ANCA, anti-GBM, Hep B/C/HIV
- Imaging: USS kidney
- Renal biopsy: only if dx remains unclear
Severity: UEs, eGFR
Outline some standard medication used in a patient with ESRF on haemodialysis
A pt with T2DM –> ESRF –> haemodialysis will be on the following drugs:
A to I
- Anaemia: EPO + IV iron (do iron studies)
- Bone-mineral disease: alphacalcidol + phosphate binders (cinacalet etc)
- Cardiovascular:
- Antihypertensives: ACE-Is (/ARBs) + CCB/beta-blocker (+/- loop diuretic if producing urine)
- Statins
- Anticoagulation - consider aspirin (uraemia interacts w clotting cascade)
- Diabetes: stop metformin, replace with gliclazide / gliptins / insulin
- insulin cleared renally so less needed as eGFR drops
- haemodialysis revoves Glu but not insulin –> hypo risk
- Electrolytes: monitor, include bicarb in haemodialysis
- Fluid balance
- Gastric protection (PPI) and Gout prophylaxis (allopurinol)
- Healthy diet (low potassium)
- Infection: line care, antibiotics if infection
Identify the possible complications of chronic kidney disease (CKD)
- Immediate: metabolic acidosis (failure to excrete H+), pulmonary oedema, hyperkalaemia
- Early: protein malnutrition, anaemia
- Late: secondary hyperparathyroidism –> renal osteodystrophy, cardiovascular disease (uraemic cardiomyopathy)
(BMJ)
Generate a management plan for chronic kidney disease (CKD)
- Medical
- Treat cause: optimise T2DM, HTN tx etc
- Medication in ESRF: A to I
- Minimise proteinuria (as damages kidney)
- lower BP (ACE-inhibitors esp good)
- Dialysis
- Peritoneal dialysis
- Haemodialysis
- Surgical
- Transplant
- immunosuppression (alemtuzumab/basiliximab + ciclosporin/tacrolimus)
- Transplant
Generate a management plan for urinary tract calculi
- If <5mm and no obstruction: will pass w/i 4w
- If obstruction:
- <10mm stone:
- 1st line: trial of passage with analgesia (1st: IM ketorolac, 2nd: morphine sulphate IM/IV) + rehydration. Escalate if unrelenting pain, no passage in 6w, one kidney, bilateral obstruction, renal failure. X-ray KUB to monitor
- tamsulosin may help passage
- 2nd line: active stone removal:
- Extracorporeal shockwave lithotripsy
- Ureteroscopy with laser lithrotripsy
- Percutaneous nephrolithotomy
- 1st line: trial of passage with analgesia (1st: IM ketorolac, 2nd: morphine sulphate IM/IV) + rehydration. Escalate if unrelenting pain, no passage in 6w, one kidney, bilateral obstruction, renal failure. X-ray KUB to monitor
- >10mm stone:
- Nephrostomy / stent to decompress kidney
- Urgent active lithotripsy (see above)
- ~20mm stone proximally:
- percutaneous nephrolithotomy
- <10mm stone:
- Obstruction + infection: emergency
- Analgesia + rehydration (as above)
- Urgent nephrostomy / ureteric stent
- IV antibiotics
- 1st: gentamicin / ciprofloxacin / levofloxacin / ceftriaxone
- 2nd: tazocin or meropenem+gentamicin
(BMJ, passmedicine)
Define polycystic kidney disease
Polycystic kidney disease (PKD) is a heterogeneous group of disorders characterised by renal cysts, with numerous systemic and extrarenal manifestations.
There are 2 types:
autosomal-dominant PKD (ADPKD). Most common
autosomal-recessive PKD (ARPKD)
(BMJ)
Explain the aetiology of polycystic kidney disease
PKD 1: AutoD, Ch16 polycystin1, 85%, presents earlier with kidney failure
PKD 2: AutoR, Ch4 polycystin2, 15%, presents later
(passmedicine)
Summarise the epidemiology of polycystic kidney disease
Caucasians mostly
PKD 1: 1/1000 prevalence
PKD 2: 1/20 000 incidence
(UpToDate)
What are the diagnostic criteria for PCKD on USS abdo?
Confirm diagnosis: USS abdo
- Ultrasound diagnostic criteria (in pts with +ve FHx)
- two cysts, unilateral or bilateral, if aged < 30 years
- two cysts in both kidneys if aged 30-59 years
- four cysts in both kidneys if aged > 60 years
(passmedicine)
Generate a management plan for polycystic kidney disease
- Conservative
- Avoid: oestrogens, cAMP increasers (eg caffeine)
- Medical
- Treat complications
- HTN: rigorous anti-HTN tx (1st: ACE-Is, 2nd: beta blocker)
- Pain: WHO analgesic ladder
- Infected cyst: co-trimoxazole or ciprofloxacin
- ESRD: 1st: transplant, 2nd: dialysis
- Treat complications
- Surgical
- Cyst drainage
- Renal transplant
(BMJ)
Identify the possible complications of polycystic kidney disease
- Early:
- Cyst infection –> sepsis
- Late:
- Cardiac complications: mitral regurgitation, aortic root dilatation, LVF
- Berry aneurysm (–> SAH)
- ESRD (–> transplant + complications)
(BMJ)
Give common drugs that must be stopped in renal failure
‘Let Me Cycle, Nitro Said’
- Lithium
- Metformin
- Tetracycline
- Nitrofurantoin
- NSAIDs
(passmedicine)
Give rheumatological causes of chronic kidney disease
- SLE: lupus nephritis (a membranous GN) in 40-60%
- Diffuse systemic scleroderma: malignant HTN –> AKI –> renal crisis
- Rheumatoid arthritis:
- NSAIDs –> acute tubular necrosis
- Penicillamine / gold –> membranous GN
(AS)
Give causes of hydronephrosis
- Unilateral: ‘PACT’
- Pelvic-ureteric obstruction (congenital, aquired)
- Aberrant renal vessels
- Calculi
- Tumours
- Bilateral: ‘SUPER’
- Stenosis of urethra
- Urethral valve
- Prostate enlargement
- Extensive bladder tumour
- Retroperitoneal fibrosis
(passmedicine)
