Week 8: Renal disease (2) (Pathology) Flashcards
AKI def
a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days.
Associated with increased mortality and morbidity
RF for AKI
- Diabetes
- CKD
- IHD/CCF/CVD
- Any major medical co-morbidity
- Elderly >75
- Sepsis
- Medications – ACEi, ARBs, NSAIDs, Antibiotics
investigations for AKI
- Urine dipstick- protein and blood
- To look for …… perform:
- Vasculitis: c-ANCA (PR3) and p-ANCA (MPO)
- Lupus nephritis: anti-GBM, ANA, C3, C4
- Myeloma: serum immunoglobulins and electrophoresis to look for myeloma
- To look for …… perform:
- Daily FBC, UandEs, LFTs, bone profile, CRP, serum bicarbonate, CK
- Urine PCR, MC+S, USS KUB
- If suspected post-streptococcal GN- anti-streptolysin O titres
- In case of associated thrombocytopenia consider HUS/TTP/Disseminated Intravascular Coagulopathy, request haemolysis screen - blood film, LDH, bilirubin, reticulocytes, haptoglobin, and call Renal SpR urgently.
- Check cryoglobulins if unexplained rash, peripheral neuropathy, hypocomplementemia, known hepatitis C, history of lymphoproliferative disorder, or +ve RhF.
management of AKI
- Discontinue nephrotoxic agents e.g. NSAID, ACEi
- Ensure volume status and perfusion pressure
- If dehydrated- IV fluids
- If overloaded- diuretics
- Aim for euvolemia
- Be aware of third space losses
- Urine output and daily bloods
- Avoid hyperglycaemia
- Treat underlying causes
- Refer to specialist
- Consider ICU admission
causes of AKI can be
prerenal
intrinsic
postrenal
prerenal causes of AKI
- Hypovolemia e.g. shock
- Decreased CO
- Decreased effective circulating volume (CCF, liver failure)
- Impaired autoregulation (NSAIDs, ACEi, ARB, cyclosporin)
intrinsic causes of AKI
- Glomerular
- Acute glomerulonephritis
- Tubules and interstitium
- Ischaemia
- Sepsis/infection
- Nephrotoxins
- Exogenous
- Iodinated contrast, aminoglycosides, cisplatin, amphotericin B
- Endogenous
- Haemolysis
- Rhabdomyolysis
- Myeloma
- Intratubular crystals
- Exogenous
- Vascular
- Vasculitis
- Malignant hypertension
- TTP-HUS
postrenal causes of AKI
- Bladder outlet obstruction- i.e. stones, stenosis, tumour
staging of AKI
Renal replacement therapy for AKI indication
- Hyperkalaemia refractory to medical therapy
- Metabolic acidosis refractory to med therapy
- Resistant fluid overload
- Uraemic pericarditis
- Uraemic encephalopathy- vomiting, confusion, drowsiness, reduced consciousness
glomerulonephritis
nephrotic/ nephriitc syndorme
nephrotic syndrome presentation
- Oedema
- Albumin <30
- Urine PCR >350 (more than 3.5 grams of protein in 24 hours)
- Hypercholesteraemia
Complications of Nephrotic syndrome include
- Higher risk of Infection
- Venous thromboembolism - DVT
- Progression of CKD
- Hypertension
- Hyperlipidaemia
causes of nephotic syndrome
- Minimal Change Disease – most common form of GN in children
- Focal Segmental Glomerulosclerosis – Idiopathic or secondary to infection, malignancy, drugs etc.
- Membranous Nephropathy – Idiopathic or secondary to infection, malignancy, drugs etc.
- Membranoproliferative Glomerulonephritis (more commonly presents as nephritic syndrome)
- Amyloidosis/Myeloma/Diabetes may have nephrotic range proteinuria but not necessarily other nephrotic features
nephritic syndrome presentation
Presentation can vary in a combination of some or many of the following:
- AKI (sometimes GFR can drop drastically)
- On urine dipstick: blood +/- and/or protein+/- Mild to moderate oedema
- Proteinuria <3.5g/24 hours
- Hypertension
- Sometimes visible haematuria
causes of nephritic syndrome
- Post streptococcal GN (post-infective)
- Weeks after group A B-haemolytic streptococci infection
- Children aged 3-12
- IgA nephropathy
- Vasculitis (ANCA associated vasculitis)
- Anti-GBM disease (Goodpasture syndrome)
- 2 peaks
- Antibodies against type IV collagen
- Associated issues with pulmonary basement membrane
- Alport syndrome
- X-lined
- Related to collagen (type V)
- Associated hearing loss and eye abnormalities
- ESRF
- Lupus nephritis
- Complication fo SLE
management of glomerulonephritis
- Supportive
- Control BP: ACEi/ARB for proteinuria
- Salt and water restriction if overloaded
- Diuretics
- If hypalbuminaemia <20g/dl then higher risk for VTE- consider LMWH
- Statins for hypercholesterolaemia
- Immunosuppressive therapy
- oral corticosteroids
- methylprednisolone
- cyclophosphamide
- tacrolimus
- ciclosporin
- rituximab
- MMF
- Azathioprine
- Invasive therapy
- Renal replacement therapy
- Plasma exchange
define chronic kidney disease
CKD is defined as the presence of kidney damage, manifested by abnormal albumin excretion or decreased kidney function, quantified by measured or estimated GFR that persists for more than three months.
classification of CKD
KDIGO looks at
- eGFR
- albumin/creatinine ratio
causes of CKD
- Diabetes
- Hypertension
- Glomerulonephritis
- Renovascular Disease
- Polycystic Kidney disease
- Obstructive nephropathy – urological problems
- Chronic/recurrent Pyelonephritis
- Others
complications of CKD
- Anaemia of Chronic Kidney Disease
- Chronic Kidney Disease – Mineral & Bone Disease
- Secondary & Tertiary hyperparathyroidism
- Hypertension
- Cardiovascular Disease – No 1 cause of Mortality
- Malnutrition/sarcopenia
- Dyslipidaemia
- As CKD progresses
- Electrolyte disturbances
- Fluid overload
- Metabolic acidosis
- Uraemic pericarditis
- Uraemic encephalopathy (indication for replacement therapy)
MDT management in CKD
- Renal physicians
- General practitioners
- Renal specialist nurses/ home care team
- Dieticians
- Pharmacists
- Vascular/transplant surgeons