Urology Flashcards
How can obstructive nephropathy or significant infection secondary to kidney stones be treated?
- Stent Insertion - placed within the ureter via cystoscopy which allows the ureter to be kept patent and temporarily relieve the obstruction.
- Nephrostomy - tube placed directly into the renal pelvis and collecting system, relieving the obstruction proximally
What is AKI?
Acute kidney injury (AKI) is a syndrome of decreased renal function, measured by serum creatinine or urine output, occurring over hours-days.
How is AKI defined?
Rise in Serum Creatinine
- >26µmol/L within 48h.
- or >1.5 × baseline within 7 days
Reduced Urine Output
- Urine output <0.5mL/kg/h for >6 consecutive hours.
What are the different stages of AKI?
What are the most common causes of AKI?
- Sepsis.
- Major surgery.
- Cardiogenic shock.
- Other hypovolaemia.
- Drugs.
- Hepatorenal syndrome.
- Obstruction.
How can AKI causes be divided up?
- Pre-renal: ↓ perfusion to the kidney
- Renal: intrinsic renal disease
- Post-renal: obstruction to urine
What are some of the RFs for AKI?
- Diabetes
- CKD
- IHD/CCF
- Elderly >75
- Sepsis
- Medications – ACEi, ARBs, NSAIDs, Antibiotics
How do we assess a patient with AKI?
- Assessment ABCDE
- C: Circulation, volume status - BP, HR, JVP, skin turgor, cap refill <2s, urine output (cathetarise)
- Hyperkalaemia: K+ on venous blood specimen + ECG
- Drugs assessment
- Examination: Full systemic exam. Palpable bladder/ kidneys, abdominal pelvic masses, renal bruits, rashes
What should you check in an AKI history?
- Risk factors
- Comorbidities
- Previous renal disease
- Recent fluid intake and losses
- New drugs including chemotherapy
- Systemic features: rash, joint pain, fr
- Other systems: productive cough, haemoptysis, GU or GI symptoms
What tests diagnose AKI?
- Bedside: Urine dip, microscopy and culture. HR and BP
- Bloods: UE, FBC, LFT, clotting, CK (rhabsomyolysis), creatinine, ESR, CRP. ABG. Blood cultures
- If blood and protein on urine dipstick – perform c-ANCA (PR3) + p-ANCA (MPO) for vasculitis, anti-GBM, ANA, C3, C4 to look for lupus nephritis, serum immunoglobulins and electrophoresis to look for myeloma
- Ipost-streptococcal GN – do Anti-Streptolysin O Titres
- Thrombocytopenia - HUS/TTP/Disseminated Intravascular Coagulopathy, request haemolysis screen - blood film, LDH, bilirubin, reticulocytes, haptoglobin, and call Renal SpR urgently.
- Cryoglobulins - if unexplained rash, peripheral neuropathy, hypocomplementaemia, known hepatitis C, history of lymphoproliferative disorder, or +ve RhF.
- Imaging: renal USS, CTKUB (no contrast)
What are the indications for renal replacement therapy?
- Fluid overload unresponsive to medical treatment.
- Acidosis: Severe/prolonged
- Hyperkalaemia: Recurrent/persistent despite medical treatment.
- Uraemia: eg pericarditis, encephalopathy (more common in ckd).
What General measures are used for for AKI management?
STOP
- Sepsis: Sepsis 6 screen + Abx (avoid nephrotoxins)
- Toxins: Stop nephrotoxic drugs: NSAIDs, ACEi, ARBs, metformin (>150mmol/L), gentamycin
-
Optimise/ Assess Volume Status:
- Look for: ↓urine volume, non visible JVP, poor tissue turgor, ↓BP/ JVP.
- Fluid overload ↑BP/ JVP, lung crepitations, peripheral oedema, gallop rhythm
- Aim for euvolaemia: consider IV fluid resuscitation: 500mL crystalloid (Hartman) 15 mins
-
Prevent Harm
- Monitoring: ICU/ HDU: check BP, JVP, urine output, CVP
- Daily: U+Es, fluid balance chart, daily weight
- Nutrition: aim for a normal calorie intake
How do you treat the underlying causes of AKI?
- Pre-renal: correct volume depletion and/or ↑renal perfusion via circulatory/cardiac support, treat sepsis.
- Renal: refer for likely biopsy and specialist treatment of intrinsic renal disease.
- Post-renal: catheter, CTKUB no contrast (look for hydronephrosis) nephrostomy, or urological intervention.
What are some of the complications of AKI?
- Hyperkalaemia
- Acidaemia
- Pulmomary Oedema
- Uraemia - encephalopathy, pericarditis
How is renal replacement therapy performed?
- Haemodialysis
- Haemofiltration
How do you manage the complications hyperkalaemia as a complication of AKI?
Hyperkalaemia
- IV Calcium gluconate STAT 10%, 10mg over 5-10 minutes
- IV fast acting Insulin (actrapid) 10 units + Dextrose/ glucose 50ml 50%
- Salbutamol: 5-10 mg via nebulizer
- IV Sodium bicarbonate (if acidotic)
-
Eliminating potassium from body:
- Calcium resonium 15-45g orally - with sorbitol or lactulose
- Furosemide 20-80mg
How do you manage Pulmonary Oedema as a complication of AKI?
Pulmonary Oedema
- O2 high flow 15L
- Venous vasodilator - diamorphine
- Furosemide 80-250mg
- If not response: urgent haemodialysis, filtration
- CPAP
- IV nitrates
What defines Nephrotic Syndrome?
- Proteinuria >3g/24h
- Hypoalbuminaemia (usually <30g/L, can be <10g/L)
- Oedema
- Hypercholesterolaemia
What are some of the causes of Nephrotic Syndrome?
-
Primary renal disease:
- Minimal change disease
- Membranous nephropathy
- Focal segmental glomerulosclerosis (fsgs),
- Membranoproliferative gn
-
Secondary causes:
- Diabetes mellitus
- SLE
- Myeloma
- Amyloid
- Pre-eclampsia
- Amyloidosis
- Paraneoplastic
What is the pathophysiology of Nephrotic Syndrome?
Podocyte pathology:
- Minimal change disease
- Membranous nephropathy: abnormal function in , immune- mediated damage
- FSGS: Podocyte injury/death in
- Membranoproliferative GN: or pathology in the gbm/endothelial cell
What is the presentation of Nephrotic Syndrome?
- Generalized, pitting oedema, which can be rapid and severe
- Look in dependent areas (ankles if mobile, sacral pad/elbows if bed-bound) and areas of low tissue resistance, eg periorbitally.
What should history taking in Nephrotic Syndrome ask about?
- Systemic symptoms, eg joint, skin
- Malignancy
- Chronic infection
What are some of the complications of nephrotic syndrome?
- Higher risk of infection
- Venous Thromboembolism
- Progression of CKD
- Hypertension
- Hyperlipidaemia
How is Nephrotic Syndrome managed?
-
Reduce Oedema:
- Furosemide IV
- Restrict their fluid intake to 1L per day
- Reduce Salt
- Reduce Proteinuria : Acei/ ARB
- Reduce Complications: anticoagulate/ statin
- Treat the underlying cause
What are some of the complications of Nephrotic Syndrome?
- Susceptibility to infections: cellulitis, strep
- Thromboembolism: DVT/ PE as blood is hypercoagulable (↑ clotting factors/ platelet abnormalities)
- Hyperlipidaemia: ↑Cholesterol/LDL/ triglycerides, ↓HDL
What is Nephritic Syndrome?
- Pathology in the glomerulus
- Present with proteinuria, haematuria, or both
- Hypertension
- Diagnosed on renal biopsy
- Can cause CKD or AKI (except minimal change disease).
How does Glomerularnephritis present?
- AKI (sometimes GFR can drop drastically)
- On urine dipstick: blood +/- and/or protein+/-
- Mild to moderate oedema
- Proteinura <3.5g/24 hours
- Hypertension
- Sometimes visible haematuria
How is Glomerulonephritis investigated?
- Urine dipstick (haematuria +/- proteinuria)
- Renal Biopsy
- Bloods: FBC, U&E, LFT, CRP; immunoglobulins, electrophoresis, complement (c3, c4); autoantibodies ana, anca, anti-dsdna, anti-gbm; blood culture, asot, hepatitis serology.
- Urine: mc&s, Bence Jones protein, rbc casts
- Imaging: CXR (pulmonary haemorrhage), renal USS
What are some of the common primary and secondary causes of Nephritis syndrome?
- Primary: IgA nephropathy, Mesangiocapillary GN
- Secondary: Post streptococcal, vasculitis, SLE, anti GBM, cryoglobuminaemia
How is Glomerulonephritis managed?
Supportive therapy:
- If suspect GN – discuss with Renal team
- MDT approach depending on underlying diagnosis
- ACEi/ARB for proteinuria
- Control BP
- Salt and water restriction if volume overloaded
- Diuretics for fluid overload
- If hypoalbuminaemic <20g/dl then higher risk for VTE – consider therapeutic LMWH
- Statins for hypercholesterolaemia
Immunosuppressive Therapy
- Specific to cause of GN – decided by Renal team (+/- Respiratory / Rheumatology teams if lung or systemic involvement )
- Oral Corticosteroids, IV pulsed methylprednisolone, Cyclophosphamide, Tacrolimus, Ciclosporin, Rituximab, MMF, Azathioprine
Invasive therapy
- Renal replacement therapy/haemodialysis for those in severe AKI or ESRF
- Plasma exchange for AAV, anti-GBM
What is Chronic Kidney Disease?
- CKD is defined as the presence of kidney damage, manifested by abnormal albumin excretion
- Or decreased kidney function (GFR<60ml/min), quantified by measured or estimated GFR that persists for more than > 3months
What GFR is kidney failure
15ml/min/1.73m2
What are some of the causes of CKD?
- Diabetes
- Hypertension
- Glomerulonephritis
- Renovascular Disease
- Polycystic Kidney disease
- Obstructive nephropathy – urological problems
- Chronic/recurrent Pyelonephritis
- Others
What are some of the complications of CKD?
- Anaemia of Chronic Kidney Disease
- CKD – Mineral & Bone Disease
- Secondary & Tertiary Hyperparathyroidism
- Hypertension
- Cardiovascular Disease – No 1 cause of Mortality
- Malnutrition/sarcopenia
- Dyslipidaemia
- Electrolyte disturbances
- Fluid overload
- Metabolic acidosis
- Uraemic pericarditis
- Uraemic encephalopathy