Renal Flashcards by Eilish Irvine

Name kidney functions

RAAS => regulates blood volume + BP
Acid-base balance
Electrolyte balance
Excretion of water-soluble waste products via filtration
Vit D synthesis => 1-alpha-hydroxylase
RBC synthetsis => EPO

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AKI vs CKI definition

AKI
- rapid decline in renal function over hours or days
- measured bye urea and creatinine
- failure to maintain homeostasis:
= oliguria, vol. overload (fluid)
= hyperkalaemia (electrolyte)
= metabolic acidosis (acid-base)
- potentially reversible

CKI
- impaired renal function for >3 months based on:
= abnormal structure/function or
= GFR <60 ml/min for >3 months
= +/- evidence of kidney damage
- usually progressive and irreversible, leads to end-stage renal failure

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AKI staging classifications

Stage I
- creatinine increase x1.5
- UO < 0.5ml/kg/hr for 6 hrs

Stage II
- creatinine increase x2
- UO < 0.5ml/kg/hr for 12 hrs

Stage III
- creatinine increase x3

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AKI signs

Hypertension
Distended bladder
Dehydration; postural hypotension
Pallor, rash, bruising (vascular disease)
Fluid overload (heart failure, cirrhosis, nephrotic syndrome)
- increased JVP, pulmonary and peripheral oedema

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AKI sx

Confusion, dehydration, underlying cause, N&V, oliguria/anuria***

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Pre-renal causes of AKI

*due to inadequate perfusion (55% cases)
Hypovolaemia
- renal loss: diuretic overdose, osmotic diuresis (DKA)
- extrarenal: D&V, burns, sweating, blood loss

Systemic vasodilation
- sepsis, neurogenic shock

Decreased cardiac output
- heart failure, MI

Intrarenal vasoconstriction
- cardiorenal syndrome
- hepatorenal syndrome

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Renal causes of AKI

*due to cellular damage (35% cases)
Acute tubular necrosis
- ischaemia, drugs, toxins (i.e. paracetamol, NSAIDs, ACEi, contrast, myoglobinuria in rhabdomyloysis)

Glomerulonephritis
- post-infection

Interstitial nephritis
- drugs, immune disorders (SLE), lymphoma, infections, tumour lysis syndrome following chemo, eosinophilia and haematuria

Vessel obstruction
- thrombosis, vasculitis, haemolytic microangiopathy

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Post-renal causes of AKI

*due to obstruction (20% causes)
Luminal
- clots, stones

Mural
- strictures, BPH, malignancy

Extrinsic compressions
- retroperitoneal fibrosis

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What types of microangopathy may cause AKI?

1) Haemolytic uraemic syndrome (HUS)

2) Thrombotic thrombocytopenic purpura (TTP)

3) Disseminated intravascular coagulation (DIC)

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Compare HUS and TTP

HUS
- occurs mainly in children after a bout of gastroenteritis caused by E.Coli 0157:H7
- poor kidney function, haematuria/proteinuria, pain and bloody diarrhoea, low Hb, low plts

TTP
- mainly occurs in women aged 10-50yo that are deficient in protease that weaves vWF (ADAMTS13)
- haemolytic anaemia, thrombocytopenia, ureaemia, fever, neurologic sx (seizures, hemiparesis, decreased consciousness, blurred vision)

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Causes of glomerulonephritis

IgA neuropathy
- after URTI, IgA complexes form

Henoch Schonlein Purpura
- purpuric rash, systemic variant of IgA

Goodpasture’s; anti-GBM antibodies
- also bind to alveolar basement membranes => lung haemorrhage

Post-strep GN
- previously healthy person presents post-throat infection

Pauci-immune
- +ANCA bond to neutrophils, activated within glomerular capillaries loops

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Nephrotic syndrome summary card

Proteinuria > 3.5g/24hrs
Oedema
Low serum albumin <25g/L

also see hyperlipidaemia as liver tries to compensate for low albumin by increasing lipids thus in hypercoaguable state
children: minimal change glomerulonephritis
adults: membranous glomerulonephritis
other causes include focal segmental glomerulosclerosis, mesangiocapillary glomerulonephritis, DM, SLE, amyloid, HBV/HCV

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Nephritic syndrome summary card

Hypertension, haematuria, oedema, oliguria (<400ml/day)

Primary causes: IgA nephropathy, mesangiocapillary glomeulonephritis
Secondary causes: post-strep, vasculitis, SLE, anti-GBM disease, cryoglobulinemia

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Ix and mx for glomerulonephritis

Ix: bloods (FBC, U&Es, CRP, complement, autoantibodies), urine, imaging (renal USS +/- renal biopsy)

Mx: treat underlying cause, steroids/immunosuppression, refer to specialist, BP mx <130/80, ACEi/ARB (decrease proteinuria and pressure on renal function as decreases intraglomerular pressure by inhibiting AGII efferent vasoconstriction)

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Which nephrotoxic agents cause renal AKIs?

NSAIDs
Contrast agents
Aminoglycosides (gentamicin, streptomycin)
ACEi, ARBs
Urate crystals
Myoglobin from rhabdomyolysis

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How does myeloma cause renal AKI?

Myeloma leads to monoclonal paraprotein production

This is deposited in the distal tubules as casts of free light chains of paraprotein precipitates, causing inflammation

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Ix for AKI

Dipstick testing
Microscopic examination = urine MCS, protein CR, 24hr urine
Proteinuria quantification
Electrolyte estimation

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What do urine dipstick results suggest?

Haematuria
- renal: pyelonephritis, glomerulonephritis, carcinoma, trauma
- extrarenal: cystitis/prostatitis/utheritis, stones, trauma (catheter), bladder/prostate/urethra cancer

Proteinuria
- nephrotic syndrome, DM

Glucose
- DM

Ketones
- starvation, diabetic ketoacidosis

Urobilinogen
- pre-hepatic jaundice

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Complications of AKIs

Uraemia, volume overload, hyperkalaemia, hyperphosphataemia, metabolic acidosis, chronic progressive kidney disease

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Mx of AKIs

General
- stop nephrotoxic drugs (incl. metformin if GFF <30)

Underlying cause
- pre-renal: correct volume depletion with appropriate fluids, Abx if sepsis, inotropes if signs of shock
- post-renal: catheretise and imaging of renal tract and urology referral
- renal: refer early to nephrology

Manage complications
- pulmonary oedema, ureaemia, acidaemia (50-100ml of 8.4% IV sodium bicarbonate with central line infusion over 15-30mins)

Renal replacement therapy
- haemodialysis and haemofiltration

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Causes and classification of CKD

Diabetes, hypertension, atherosclerosis, chronic glomerulonephritis, infective/obstructive uropathy, adult polycystic kidney disease

Staging:
I. damage, normal GFR >/= 90
II. damange, mild GFR 60-89
III. moderate low GFR 30-59
IV. severe low GFR 15-29
V. end-stage renal disease <15 (or dialysis)

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Signs and sx of CKD

Peripheral vascular disease, peripheral oedema, HTN, pallor (ACD), excoriation marks (uraemia), skin pigmentation (uraemia), renal bone disease, signs of underlying disease (i.e. SLE)

Often asymptomatic, anorexia, N&V, fatigue, pruritus, peripheral oedema, muscle cramps, pulmonary oedema, sexual dysfunction

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Ix for CKD

Bloods
- increased urea + creatinine (U&E), normocytic anaemia, glucose (DM), secondary hyperPTH (if severe), GFR, low calcium, high phosphates, high ALP in renal bone disease

Urine
- dipstick, MCS, protein:Cr ratio

Imaging
- USS (size/anatomy/corticomedullary differentiate + eliminate obstruction)
- CKD small kidneys but can be enlarged in infiltrative disorders

CXR
- pericardial effusion, pulmonary oedema

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Mx of CKD

1) Limiting progression/complications
= BP <130/80 or <125/75 if diabetic
= tight glucose control if DM
= diet with help of MDT: low protein, potassium and phosphate food
= smoking cessation, wt loss
= renal osteodystrophy: calcichew (Ca2+ supplement), calcium acetate (phosphate binders), cinacalcet (calcimimetic to decrease PTH)

2) Symptom control
= anaemia; human EPO may be required
= acidosis; sodium bicarbonate supplements
= oedema; loop diuretics, restriction of fluids

3) Preparation for renal replacement therapy
= haemodialysis; vascular access required
= transplantation; gold standard, major surgery with life-long immunosuppression

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Pathogens that cause UTIs

Common: E. Coli (gram-negative anaerobic) Staph saprophyticus (gram-positive coccus) Proteus mirabilis Enterococci Immunocompromised: Klebsiella Candida albicans Pseudonomas aeruginosa

RFs for UTIs

Female >>> male Sexual intercourse Exposure to spermicide Pregnancy Menopause Immunocompormised Catheritisation UT obstructon UT malformation

Ix for UTIs

Urine dipstick: + nitrates MSU for urine MCS: WBC, provide colony forming unti, sensitivity Bloods: FBC, CRP, U&Es Complicated UTI: renal USS/IV urography

Mx for UTIs

Uncomplicated - cefalexin 500mg 3 days or nitrofurantoin 500mg 7 days - cefalexin; co-amoxiclav if pregnant Male - 7 day course of cefalexin/ciprofloxacin 500mg Pyelonephritis/urosepsis - co-amoxiclav 1-2mg IV +/- amikaxin or gentamicin first 1-2 days

Polycystic kidney disease summary card

ADPKD 1 and 2 - adult onset one occurs 30-60yo - hx: acute loin pain, stone formation, sx of renal failure, abdo discomfort, FHx of berry aneurysms (SAH) - o/e: HTN, renal enlargement, abdo pain +/- haematuria - ix: haematuria, increased Hb, damaged U&Es, abdo USS, MRI angiography if 1st-degree SAH + ADPKD

Renal cell carcinoma summary card

Associated with von Hippel-Lindau syndrome Tumours include von Grawitz, hypernephroma - presents: fevers, night sweats, polycythaemia, varicocoele (due to invasion of left renal vein) - triad: haematuria, abdo mass, loin pain - RFs: male, old, HTN, smoking, obesity, dialysis, vHL, tuberous sclerosis - ix: RBCs in urine, increased BP, filling defect + calcification via CT/MRI, Iv urogram, ALP (bone mets), polycythaemia or IDA, cannon ball mets (lungs)

Renal artery stenosis summary card

Hypoperfusion activation leads to RAAS therefore increased BP, contributing to fibrosis, glomerulsclerosis and renal failure - atherosclerosis (80% cases), fibromuscular dysplasia (10% cases, young females with string of beads on imaging) - abdominal and carotid or femoral bruits, weak leg pulses, flash pulmonary oedema, worsening renal function after ACEi/ARB in bilateral RAS, increased BP refractory to tx - ix: USS kidney size, CT angiogram of MR angiogram; risk of contrast nephrotoxicity caution, digital subtraction renal angiography (gold standard)

A 34-year-old man, Ross, has lost a significant amount of blood following a motorbike accident. His blood test results include a serum urea of 20.2 mmol/L, a creatinine of 220 μmol/L, a potassium of 5.7 mmol/L and a sodium of 137 mmol/L. Urine electrolytes and osmolarity are normal. A CT scan confirms that there was no damage to the kidneys during the accident. What is the most likely impression? A Pre-renal AKI 2°to hypovolaemia B Pre-renal AKI 2° to coarctation of aorta C Post-renal AKI 2° to prostatic hypertrophy D Renal AKI 2° to glomerulonephritis E Haemolytic uraemic syndrome

A Pre-renal AKI 2°to hypovolaemia

An 65-year-old, Nancy had seen her GP after straining her back while lifting a heavy box. She was prescribed a course of diclofenac. Five days later, she presents to the emergency department feeling generally unwell and slightly confused. Blood tests confirm that she is in acute renal failure. What is the most likely impression? A Pre-renal AKI 2°to hypovolaemia B Acute tubular necrosis C Interstitial renal failure 2° to glomerular nephritis D Interstitial renal failure 2°to NSAIDs E Analgesia nephropathy

E Analgesia nephropathy

A 25-year-old man, Harry presents to the emergency department complaining of severe loin pain and vomiting. He has had three episodes of this pain today, each lasting 10 minutes. On examination, he is pale, sweaty and tender in his right loin. A urine dipstick shows 3+ blood, 1+ protein, no nitrites and no leucocytes. What is the best investigation to reach a diagnosis? A Cystoscopy B KUB X-ray C Renal tract ultrasound scan D CT-KUB E MSU for MCS

D CT-KUB

A 40-year-old man, Gareth, presents with a 2-week history of coughing up blood. He is found to have 2+ of protein in his urine on dipstick analysis. Blood tests show a urea of 9.5 mmol/L and a creatinine of 148 μmol/L. Further tests confirm that he is positive for the anti- glomerular basement membrane antibody What is the most likely diagnosis A IgA nephropathy B Membranous glomerulonephritis C Rapidly progressive glomerulonephritis D Minimal-change glomerulonephritis E Goodpasture’s syndrome

E Goodpasture’s syndrome *type II hypersensitivity reaction

A 25-year-old man, Timothée, presents with facial and ankle swelling. He is found to have 3+ of protein in his urine on dipstick analysis. Blood tests reveal an albumin of 16 g/L. What is the most likely diagnosis A IgA nephropathy B Membranous glomerulonephritis C Rapidly progressive glomerulonephritis D Minimal-change glomerulonephritis E Goodpasture’s syndrome

B Membranous glomerulonephritis

2/7 dysuria + frequency + offensive urine Which renal ix should you do?

MSU for MCS

Severe loin pain, vomiting Haematuria dipstick Which renal ix is most sensitive to pick up diagnosis?

Non-contrast CT-KUB

Recurrent UTI, FTT, baby FHx of vesico-ureteric reflux Which renal ix should you do?

USS of renal tract

India + weight loss + night sweats, UD: blood, leukocytes (sterile pyuria) Urine sample: no growth (-ve culture) Which renal ix should you do?

3 early morning urine samples for Microscopy, culture, ZN staining

Transplanted kidney worsening renal function over 2/52, pain around area, Transplant 4/12 ago Which renal ix should you do?

Renal biopsy

Muddy brown cast + high creatinine High urine sodium, low urine osmolality Low urine:serum urea ratio Low urine:plasma osmolarity ratio Diagnosis?

Acute tubular necrosis

Unwell after ACEi Bilateral renal bruits, Hx of IHD Diagnosis?

Pre-renal acute renal failure 2° renal artery stenosis

Esoinophilic cast, urine dip: protein+blood Old man, CAP, penicillin Tx, dysuria, back pain Diagnosis?

Acute interstitial nephritis

Bladder palpable up to umbilicus + unable to pass urine + man Diagnosis?

Post-renal AKI 2° to prostatic hypertrophy

D&V + high urea + creatinine + K+ Normocytic anaemia + fractionate RBC (film) Escherichia coli O157:H7 stool Diagnosis?

Haemolytic uraemic syndrome

HUS + Fever + neurological manifestations Diagnosis?

TTP

24 years of rheumatoid + develop peripheral oedema Proteinuria 3+ urine Cause?

Amyloidosis

Bone pain, lethargy, poor renal function Monoclonal band on serum electrophoresis Monoclonal globulin protein in urine Cause?

Multiple myeloma

Crohn’s, poor renal function, proteinuria Stain +ve with congo red – renal Biopsy Cause?

Amyloid A amyloidosis

T1DM albuminuria, previous dipstick normal Cause?

Diabetic microalbuminuria

Collapse following stroke: High urea + creatinine, K+, High CK, urine dark red Cause?

Rhabdomyolysis

4M, facial swelling, 3+ proteinuria, low albumin Diagnosis and what would microscopy show?

Minimal change glomerulonephritis Electron microscopy: Fusion of podocytes

25M, facial swelling, 3+ proteinuria, low albumin Diagnosis?

Membranous glomerulonephritis

+ve anti-GDM antibodies Diagnosis?

Goodpasture's syndrome

7M 2/7 after URTI hematuria, flank pain Biopsy: Proliferative glomerulonephritis with antibody deposition Diagnosis?

IgA nephropathy (Berger’s disease)

15F, 2/52 post-tonsilitis, dark urine, puffy High titres of anti-streptolysin O antibody Diagnosis?

Post-strep glomerulonephritis

A 75 year old man is admitted with community acquired pneumonia. On examination, his abdomen is soft and non-tender. The bladder is not palpable. A urinary catheter bag at the bedside contains a small amount of concentrated urine. He has dry mucous membranes, reduced skin turgor and his JVP is not visible. Bloods: Creatinine 362μmol/L (120μmol/L – 1 month ago) What is the most appropriate immediate management option? A IV fluids B IV furosemide C USS kidneys D Urgent urology referral E Haemodialysis

A IV fluids

A 67 year old man presents with a long history of fatigue, nausea and poor appetite. He has a past medical history of type 2 diabetes mellitus and hypertension. You suspect this patient’s presentation is due to chronic kidney disease. Which of the following can be used to stage chronic kidney disease? A Blood pressure B Haemoglobin C Creatinine D Potassium E HbA1c

C Creatinine to calculate GFR

A 32 year old woman is feeling tired for the past 3 days. Over this time she has noticed that has only passed small amounts of concentrated urine. She is normally fit and well. She was successfully treated with oral antibiotics for a sore throat 2 weeks ago. Blood pressure: 145/95mmHg Urine dipstick: protein 1+, blood 2+ What is the most likely diagnosis? A Acute tubular necrosis B Acute interstitial nephritis C Glomerulonephritis D Pyelonephritis E Urinary tract calculus

C Glomerulonephritis post-strep

A 45 year old woman has noticed that her face and legs have become swollen gradually over the last 6 months. She has no past medical history and takes no regular medications. Blood pressure: 120/80mmHg Urine dipstick: protein 3+, blood neg What is the most likely diagnosis? A Acute tubular necrosis B Acute interstitial nephritis C Glomerulonephritis D Pyelonephritis E Urinary tract calculus

C Glomerulonephritis membranous glom. most common reason for nephrotic syndrome in adults

A 45 year old woman is found to be hypertensive. Her mother was recently admitted to hospital for a subarachnoid haemorrhage and has been on haemodialysis since the age of 50. On examination: Bilateral palpable abdominal masses. Urine dipstick: leukocytes neg, nitrites neg, blood + What is the most likely diagnosis? A Glomerulonephritis B Primary (essential) hypertension C Conn’s syndrome D Polycystic kidney disease E Renal artery stenosis

D Polycystic kidney disease

A 69 year old man with known coronary artery disease and peripheral vascular disease presents with an acute kidney injury. Ramipril has recently been started for resistant hypertension. What is the most likely underlying diagnosis? A Renal artery stenosis B Renal cell carcinoma C Phaeochromocytoma D Conn’s syndrome E Cushing’s syndrome

A Renal artery stenosis

A 36 year old woman presents with a 2 day history of fever and right-sided back pain. She also describes pain on passing urine. She is normally fit and well. On examination: Right-sided costovertebral angle tenderness. HR 110bpm, Temp 39.2ºC Urine dipstick: leukocytes ++, nitrites ++, blood + What is the most likely diagnosis? A Lower urinary tract infection B Acute pyelonephritis C Urinary tract calculus D Glomerulonephritis E Acute tubular necrosis

B Acute pyelonephritis

A 66 year old male smoker presents with a 3 month history of dull left flank pain. No significant past medical history or family history. On examination: Left-sided palpable abdominal mass. Urine dipstick: leukocytes neg, nitrites neg, blood + What is the most likely diagnosis? A Acute pyelonephritis B Urinary tract calculus C Glomerulonephritis D Renal cell carcinoma E Polycystic kidney disease

D Renal cell carcinoma

What AKI does the pt have if the following is found: a) brown cell casts in urine, b) white cell casts in urine, c) eosinophilia in renal biopsy?

a) Acute tubular nephritis (85% cause of intrinsic AKIs) b) Infective acute interstitial nephritis (likely pyelonephritis - UTI sx) c) Non-infective acute interstitial nephritis (likely acute hypersensitivity - reaction to drugs, also has a rash)

Compare nephritic and nephrotic syndrome

Nephritic (think nephritis, inflammation, something disrupting glomerulus so blood getting out) P roteinuria H aematuria A zotemia (high urea) R ed cell casts O liguria H ypertension Nephrotic (think nephrosis, structural problem, something in glomerulus) H ypoalbuminaemia E dema L ipid abnormalities P roteinuria

Key causes of AKIs

Sepsis Toxicity Obstruction Parenchymal disease