Nephrology Flashcards
AKI
Rapid dysfunction of kidney over day/hours which leads to accumulation of nitrogenous waste and fluid. Measured by serum creatinine or UO
Pre-renal (reduced perfusion of kidneys, otherwise healthy kidneys )
Sepsis
Hypovolaemia
Drugs - ACi, ARB, NSAISs (renal vasoconstriction)
Ix:
Low urinary Na (as trying to reabsorb as much Na to keep vol up)
High urine osmolality
High urea/N creatinine
Renal (intrinsic injury to kidney) ATN (prolonged hypotension, nephrotoxins causing renal damage ) Glomerulonephritis Vasculitis HUS, TTP, DIC
Ix:
High urinary Na
Low urinary osmolality (as tubules damaged so can’t reabsorb Na and concentrate the urine)
Low urea/N creatinine
Post-renal (obstruction in renal tract - leads to decrease in GFR) Stones Malignancy Stricture Prostatic hypertrophy
Ix:
High urea/high creatinine
Classification
1: 1.5x creatinine baseline, UO >0.5 for 6-12 hrs
2: 2x creatinine baseline, UO <0.5 for >12 hrs
3: 3x creatinine baseline, UO <0.3 for >24 hrs
Sx:
History of IV contrast, nephrotoxic drugs, infection
Vasculitis: joint pain, rash
Bladder obstruction: nocturia, poor flow
Sepsis (fever)
Hypovolaemia (dry mucous membranes, hypotensive)
Fluid overload (creps, peripheral oedema)
Ix: UEs (urea/creatinine, K+ (high) ECG (high K+ broad QRS, tall tented T waves, small/no P wave) CXR (pulmonary oedema) ABG (metabolic acidosis) Glomerulonephritis screen - ANCA, ANA CK (rhabdomyolysis) Renal US (obstruction)
Tx:
Hypovolaemia, give IV fluids (Hartmann's unless high K+, saline has risk of hyperchloraemia acidosis) Hypervolaemia: Fluid restriction, diuretics, refractory fluid overload: dialysis Acidosis: Sodium Bicarb Hyperkalaemia: >6.5 or >6 with ECG changes Calcium gluconate (protects heart). IV insulin+dextrose (moves K+ into cells). Salbutamol nebs (reduces serum K+). Calcium resonium (eliminates K+ from gut) Dialysis if refractory
Pre-renal: correct volume depletion, treat underlying sepsis
Renal: Stop nephrotoxic drugs, biopsy
Post renal: catheter, nephrostomy
Causes of ATN
Due to hypoperfusion, or nephrotoxic drugs leading to damage to kidney
Causes:
Exogenous: Drugs, (gent, ACEi), Contrast
Endogenous: Myoglobin, Hb, Calcium
Indications for renal replacement therapy
Absolute indications:
Refractory fluid overload
Refractory hyperkalaemia
Relative:
Acidosis
Uraemia (encephalopathy, pericarditis)
Toxins (BLAST - Barbiturates, Lithium, Alcohol, Saclicylates, Theophylline)
CKD
Abnormal structure or kidney function present >3mnths, or sustained fall in GFR >60
Classification 1 >90 (only CKD if other kidney damage i.e protein/haematuria) 2 > 60 mild 3 > 45 mod 4 > 30 severe 5 > 15 kidney failure
Causes: Diabetes (most common) Glomerulonephritis HTN Vascular disease UTI, heart failure
Decreased GFR, and albuminuria indicators of prognosis
Ix:
FBC (anaemia - as less EPO made)
Phosphate (high)
Calcium (low) (Kidney fails to excrete phosphate and make Vit D)
PTH increases - secondary hyperparathyroidism
(As when Ca2+ low, PTH released to increase Ca+ absorption from gut via Vit D, increase Ca2+ efflux from bone) and bone disease (renal osteodystrophy)
UEs (K+ high)
Sx: If GFR<30: symptomatic Anaemia (pallor, fatigue) Fluid overload (pulmonary oedema, SOB) Bone pain (renal osteodystrophy) Nausea, vomiting
Signs: Anaemia (conjuctival pallor), peripheral oedema, uraemic flap, yellow tinge (uraemia), jaundice (hepatorenal syndrome)
Ix:
FBC (normochromic normocytic anaemia)
UEs (serum creatinine, high phosphate, low Ca+, high PTH)
urine: dipstick, culture, albumin/protein:creatinine
renal US (<9cm small in CKD except myeloma/amyloidosis, if asymmetrical: renovascular)
Renal biopsy: nephrotic syndrome
Tx:
ACEi/ARB (aim BP <140/90), statin, other antihypertensives e.. atenolol
BM control
Lifestyle advice (smoking, restrict salt intake)
Anaemia (give EPO)
Reduced oral phosphate, phosphate binders (calcium carbonate), Vit D,
Renal replacement therapy (if stg 5, or ureamia - acidosis, hyperkalaemia)
Renal replacement therapy
Haemodialysis - 3 times/wk 4 hrs.
Blood leaves through AV fistula and returned via dialysis transverse membrane and dialysis solution flowing in opposite direction, so waste removed from blood to solution via concentration gradient.
Problems: AV fistula can thrombose, infection, cerebral oedema
Peritoneal dialysis
Catheter inserted in abdomen and fluid infused, allowing toxic waste products and fluid to be removed, with peritoneum as the semi-permeable membrane
Advantages: can be done at home
Problems: peritonitis, hernia, infection at catheter site
Complications: cardiovascular disease, infection, renal bone disease
Transplant
Contraindications: malignancy, active infection
Complications:
Acute (within 6 mnths) - fever, pain over graft, rising creatinine. Steroids
Chronic rejection - gradual decline in kidney function, scarring
Infection - increased risk of all. Porphylactic treatment for CMV, pneumocystis jirovecii
Malignancy - increased risk of skin and gynae Ca.
UTI
LUTI (lower urinary tract infection)
Cystitis - dysuria, urgency, frequency, suprapubic pain, haematuria
UUTI (upper urinary tract infection);
Pyelonephritis - fever, vomiting, loin pain, cystitis symptoms
Prostatitis: pain in scrotum, bladder, lower back, fever nausea, tender prostate. Complications: prostatic abscess
Signs: fever, abdo/loin pain tenderness, distended bladder
Risk fx: sexual activity, dehydration, diabetes, immunosuppressed
Gram -ve: E.coli, Klebsiella, proteus
Gram +ve: Streptococcus, enterococcus
Ix:
In non-pregnant women, if >3 symptoms of cystitis,no vaginal discharge - no need to test - treat
Dipstick
MSU culture >10^5 colony forming units) - use in pregnant women, children, men
Blood tests: if systemically unwell, FBC, UEs, blood cultures
USS, cystoscopy - in men with UUTI
Tx:
Non-pregnant women, >3 symptoms cystitis and no vaginal discharge - 3 days nitrafurantoin, trimethoprim
Pregnant women: UTI assoc. with pre-term delivery. Avoid Tri (1st term), Nitro (near term), Amoxillin safe
Men: Tri or nitro for 7d
Prostatitis: refer to urology, ciprofloxacin
Upper UTI without sepsis (non pregnant women and men): ciprofloxacin
Upper UTI with sepsis: IV Gent
Complicated UTI: Catheter associated UTI Complications of catheter: infection, trauma, hydronephrosis Tx: remove catheter, send urine IV Gent before remove catheter
Pyelonephritis
Sx: fever, rigors, loin pain
Complications: renal abscess, emphysematous pyelonephritis (gas bubble appearence on kidney)
Tx: Cipro
Causes of pyruia? (pus in urine)
TB
Tumours
Calculi
Glomerulonephritis
Group of disorders characterised by inflammatory changes in glomerulus and tubules
Secondary causes: Infection, Hep B/C, drugs - NSAIDs, SLE, amyloidosis
Nephritic syndrome
Blood and protein (<3/g) in urine, high blood pressure, rising serum creatinine
Hypoabuminaemia/oedema can occur
Reduced UO
IgA, Henoch Schonlein pupura, post-strep GN
RPGN (rapidly progressive glomerulonephritis)
Rapid rise serum creatinine, crescentic damage
Granulomatosis polyangiitis, Good pasture’s, lupus
Nephrotic syndrome
Proteinuria, Hypoalbuminaemia, oedema, hyperlipidaemia
Minimal change, focal segmental glomerulosclerosis, Membranous
Nephritic GN
IgA nephropathy
Commonest primary GN
Asymptomatic. Recurrent episodes frank haematuria. Can occur same time with resp infections.
High BP. Indolent.
Can progress to renal failure
Can be precipitated by coeliac, cirrhosis
Ix: renal biopsy. IgA deposition in mesangium
Tx: ACEi (reduce proteinuria), corticosteroids if proteinruria persistent
Henoch Schonlein
Sx: Purpuric rash on extensor surfaces, joint pain, abdo pain, nephritis
Post-streptococcal GN
Throat or skin infection (1-2 weeks after)
Stretococcal (Strep pyogenes) antigen deposits in glomerulus leading to immune complex formation and inflammation
Ix: anti-streptolysin O antibody
Sx: proteinuria, oedema, increased BP
Tx: abx
Rapidly progressing GN
Group of disorders with glomerula crescents on biopsy
90% progressive to ESRF
Causes:
ANCA vasculitis (Granulomatosis with polyangiitis)
Goodpastures syndrome
Ix: UEs, urine (dip), albumin/protein:creatinine, US
GN screen:
HbA1c; diabetic nephropathy
ANCA; vasculitis
ANA/Anti-PLAR2; membranous nephropathy
Complement/dsDNA; Lupus
Complement; focal segmental glomerulosclerosis
Tx: steroids, cyclophosphamide, plasma exchange (remove anti-GBM for goodpasture’s)
Granulomatosis with polyangiitis Sx: upper (stridor, saddle nose deformity) and lower resp tract (cough, dyspanoea), kidney (haematuria, oedema) Fatigue, weight loss, night sweats Ix: urinalysis, chest CT, ANCA Tx: corticosteroids+cyclophosphamide
Goodpastures’s syndrome
Anti-GBM antibodies against type 4 collagen
Assoc with HLA DR4
Sx: haemoptysis - pulmonary haemorrhage, SOB, fever, rapidly GN
Ix: renal biopsy: linear IgG deposits on basement membrane
Tx: prednisolone+plasmapheresis
Nephrotic syndrome
Secondary causes: DM, lupus nephritis, myeloma
Sx: oedema (periorbital), pleural effusion, frothy urine
Membranous nephropathy
Immune complexes deposit in space between podocytes and glomerular basement membrane
Most common primary cause
Can be due to malignancy (lung, breast GI) , drugs - NSAIDs, penicillamine
Ix: Anti-phospholipase A2 receptor antibody
Tx: treat underlying disease, supportive: ACEi, diuretis,
immuno: steroids, cyclophosphamide
Minimal change Commonest GN in children Sx: acute, may be after resp infection Ix: electron microscopy: effacement of epithelial foot processess Tx: prednisolone, diuretics
Complications nephrotic syndrome:
Increased risk of infection, venous thrombosis (hypercoagulable state, hyperlipidaemia
Congenital disease of kidney
Adult polycystic kidney disease
Autosomal dominant:
PKD1 ch 16 (85%)
PKD2 ch 4
Sx: loin pain, haematuria, progressive renal failure
Signs: liver, pancreatic cysts, intracranial aneurysm leading to SAH, mitral valve disease - murmur
Ix: USS 15yrs-39: >3 cysts 40yrs > 2 cysts in each kidney Urinalysis Genetic testing Tx: 3L water intake, ACEi (if high BP), IV abv+cyst drainage if infected cyst
Autosomal rec APKD
ch 6
Ante-perinatally with renal cysts, hepatic fibrosis
USS: salt and pepper appearence
Alports syndrome
X-linked (men)
mutation in COL4A5 gene which encodes type 4 collagen
Sx: Avg age 40yrs renal failure, sensorineural hearing loss, eye abnormalities
Fabry disease
X-linked
Lysosomal storage disorder, deficiency of enzyme alpha- galactosidase A
Sx: hearing loss, rash/skin lesions
Signs: proteinuria, renal failure, lipid in urine
Ix: Biopsy - zebra body
Systemic disease of kidney
Diabetic nephropathy
Commonest cause of end-stage renal failure
Defined as albuminuria, with reduced GFR in setting of long standing diabetes
High glucose - increased glomerular pressure - podocyte damge - endothelial dysfunction - scarring - nodular formation (Kimmelsteil Wilson lesion) - fibrosis
Ix: albumin:creatinine (early morning sample) -
microalbuminuria (moderately increased albuminuria)
US kidneys: bilateral enlarged/normal
Tx: Glycaemia control, BP control (ACEi), statins, reduced salt intake
Atherosclerotic renovascular disease
Athersclerotis - development of cholesterol plaques in renal artery (usually proximal) - unilateral or bilateral.
Usually systemic so may have vascular disease elsewhere e.g. coronary, peripheral
Sx: angina, intermittent claudiaction
Signs: HTN, flash pulm. oedema
Ix: urinalysis (normal) serum creatinine (high) USS kidney (assymetrical) MRI angiography (of renal arteries) - severity of stenosis
Tx: Modify CV risk fx: aspirin, anti-hypertensive, statin
Percutanous angioplasy - refractory HTN, recurrent flash pulm oedema
Amyloid
Production of abnormal folded protein which is degradation resistant (amyloid) which can be deposited in kidneys, spleen, liver
Type AA: serum amyloid - chronic inflammation
Type AL: light chains in myeloma
Sx: raised JVP, oedema (due to nephrotic syndrome), heptaomegaly, periorbital pupura, macroglossia
Ix: Congo red stain on biopsy
Lupus nephritis
Autoimmune disease against dsDNA. Antibody complexes form causing tissue inflammation and damge.
Sx: malar rash, photosensitive, arthritis, nephritis/nephrosis
Ix:
FBC (anaemia)
UEs (high urea, creatinine)
ANA, Anti dsDNA
Low complement (esp. 4)
Tx: cyclophosphamide+prednisolone+hydroxychloroquine
Acute interstitial nephritis
Sx: rash, fever, arthalgia , Causes: drugs - NSAIDs, PPIs, Rifampicin, diuretics, warfarin infections: streptococcus autoimmune: SLE Ix: urine microscopy: eosinophilic casts Tx: stop agent. Treat cause
What is indicated if urea much higher than creatinine?
Dehydration
