Renal Flashcards
how to measure AKI
serum creatinine (need to adjust for muscle bulk)
- Rise in creatinine > 25 micromol/L in 48 hours
- Rise in creatinine > 50% in 7 days
- Urine output< 0.5 ml/kg/hour over at least 6 hours
RF for developing AKI
- > 65yrs
- sepsis
- CKD
- Heart failure
- diabetes
- liver disease
- reduced fluid intake
- medications (NSAID, gentamicin, diuretics, ACEi)
- radiocontrast agents
causes of renal impairment
Pre-renal- MC
- dehydration
- sepsis or blood loss
- heart failure
Renal
- acute tubular necrosis MC
- glomerulonephritis
- acute interstitial nephritis
- HUS
- rhabdomyolysis
Post-renal
- kidney stones
- tumour
- urethral stricture
- BPH
- neurogenic bladder
acute tubular necrosis
- necrosis of epithelial cells in renal tubules
- MC intrinsic cause of AKI
- due to ischaemia or nephrotoxins
- muddy brown casts
- recovery 1-3 weeks
acute interstitial nephritis
- inflammation of interstitium
- caused by immune reaction assoc with NSAIDs, abx, infections, autoimmune conditions
- rash, fever, flank pain, eosinophilia
- treat cause + steroids
Mx of AKI
A-F
A- anaemia (give erythropoieitin)
B- bones (phosphate and calcium)
C- clearance (creatinine)
D- drugs (withhold ACEi and NSAIDs)
E- electrolytes (potassium and phosphate)
F- fluid balance (BP 130/80)
effect of ACEi in AKI
will drop BP and renal perfusion
complications of AKI
- fluid overload, heart failure, pulmonary oedema
- hyperkalaemia
- metabolic acidosis
- uraemia
stages of AKI
- 1.5-2x creatinine rise from base and <0.5ml/kg/hr urine >6hr
- 2-3x Cr rise + <0.5ml >12hr
- > 3x Cr rise + <0.3ml >24hr
how to manage hydropnephrosis
nephrostomy
nephrotic syndrome
BM of glomerulus becomes highly permeable
- proteinuria (frothy urine)
- hypoalbuminaemia
- oedema
causes of nephrotic syndrome
- Minimal change disease (MC)
- Membranous nephropathy
- focal segmental glomerulosclerosis
- diabetes, HSP, SLE, HIV
complications of nephrotic syndrome
- DVT: increased risk of thromboembolism related to loss of antithrombin III and plasminogen in the urine
- ACS and stroke due to hyperlipidaemia
- CKD
- increased risk of infection due to urinary immunoglobulin loss
- hypocalcaemia (vitamin D and binding protein lost in urine)
Minimal change disease
- idiopathic
- 2-5 y/o child
- Mx steroids. 2nd line cyclosporin
nephritic syndrome
PHAROH
- Proteinuria
- Haematuria
- Azootemia
- Red cell casts
- Oliguria
- Hypertension
Causes of nephritic syndrome
- Acute postinfectious (post-strep) glomerulonpehritis
- IgA nephropathy (berger disease)
- Rapidly progressive GN
- Hereditary nephritis
- thin BM disease
IgA nephropathy
- MC cause of primary GN
- 20y/o with haematuria
- unknown cause
- IgA deposits
- rule of thirds for recovery, CKD and progressive CKD
Post-streptococcal GN
- <30y/o
- 1-3 weeks after strep infection
- make full recovery
rapidly progressive GN
- acute severe illness
- respond well to treatment
- glomerular crescents on histology
anti-GBM
p-ANCA
c-ANCA
anti-GBM= goodpasture
p-ANCA= microscopic polyangiitis
c-ANCA= granulomatosis with polyangiitis
Mx of glomerulonephritis
- Diagnosis- renal biopsy
- supportive care
- immunosuppression (steroids)
causes of CKD
- diabetes
- hypertension
- Meds (NSAIDs, lithium)
- Glomerulonephritis
- PCKD
Presentation of CKD
- fatigue
- pallor
- foamy urine
- nausea
- loss of appetite
- pruritus
- oedema
- hypertension
- peripheral neuropathy
Ix for CKD
- eGFR
- urine albumin: creatinine
- urine dipstick
- renal USS
stages of CKD
GFR
1. kidney damage with normal GFR >90
2. GFR 60-89
3a. moderate 45-59
3b. moderate 30-44
4. severe 15-29
5. ESRF <15 or dialysis
A:C
A1 <3
A1 3-30
A3 >30
complications of CKD
- anaemia
- renal bone disease
- CVD
- peripheral neuropathy
- ESKD
- dialysis related complication
Mx of CKD
- optimise diabetes and hypertension
- avoid nephrotoxic drugs
- treat glomerulonephritis
- BP < 130/80
- ACEi and SGLT2 slow progression
- atorvastatin for CVD prevention
- erythropoietin/iron
- vit D, low phosphate diet and phosphate binders
- dialysis and transplant
before giving erythropoietin in CKD what do you need to correct
iron
oral if not corrected after 3 months give IV
Renal bone disease
- high serum phosphate, low vit D activity + low serum Calcium
- kidneys activate vit D and increasing calcium
- low calcium and high phosphate = more PTH–> secondary hyperPTH
- –>increase osteoclast activity and calcium bone absorption
- –> osteomalacia, osteosclerosis
indications for short term dialysis
AEIOU
- acidosis
- electrolyte imbalance (hyperkalaemia)
- intoxication
- Oedema
- Uraemia sx (seizures and reduced GCS)
indication for long term dialysis
ESRF
haemodialysis
- 4hrs a day 3x a week
- need anticoagulation with citrate or heparin to prevent blood clotting in machine
- can use tunnelled cuffed catheter in subclavian/jugular or AV fistula
complications of AV fistula
- anaeurysm
- thrombosis
- infection
- stenosis
- high output heart failure
- STEAL syndrome: ischaemia of part of limb
signs in a fistula
- palpable thrill
- machinery murmur on auscultation
peritoneal dialysis
- uses peritoneal membrane
- can do it at home
- Tenckhoff catheter
complications of peritoneal dialysis
- bacterial peritonitis
- peritoneal sclerosis
- ultrafiltration failure
- weight gain
- psychosocial implications
years added from renal transplant compared to dialysis
10 yrs
donor matching for renal transplant
HLA type on Chr6
Where and how is kidney transplant done
- donor kidney BVs anastomosed with pelvic vessels (external iliac vessels).
- ureter of donor kidney anastomosed with bladder
- donor anterior in abdo in iliac fossa
- hockey stick (Rutherford Morrison) scar
post transplant care
- 2x doses Basiliximab to prevent acute rejection
lifelong immunosuppression
- tacrolimus
- mycophenolate
- ciclosporin
- azathioprine
- prednisolone
side effects of immunosuppressants
- seborrhoeic warts and skin cancer
- tacrolimus = tremor
- cyclosporin = gum hypertrophy
- steroids = cushing’s syndrome
complications of renal transplant
- rejection (HA, A, Chronic)
- transplant failure
- electrolyte imbalance
Causes of hyperacute rejection (minutes-hours)
- pre-existing antibodies against HLA or ABO antigens
Causes of acute rejection (<6months)
- mismatched HLA
- Cell-mediated (cytotoxic T cells)
- CMV
Causes of chronic rejection (>6 months)
- antibody and cell-mediated mechanisms cause fibrosis to the transplanted kidney
- recurrence of original renal disease
complications of transplant related to immunosuppressants
- IHD
- T2DM
- infections
- Non hodgkin lymphoma
- skin cancer (SCC)
infections secondary to immunosuppressant meds
- Pneumocystitis jiroveci pneumonia (PCP)
- CMV
- TB
what is glomerulonephritis
inflammation of glomeruli in kidney
What is renal tubular acidosis
metabolic acidosis due to pathology of tubules
types of renal tubular acidosis
T1: distal tubule cannot excrete H+. high urine pH and low serum K+. most severe
T2: proximal tubule cannot reabsorb bicarbonate. High pH and low K+. Milder
T4: low aldosterone or impaired aldosterone function. low pH, high K+. MC.
T3: RARE
Causes of type 1 renal tubular acidosis
- Genetic
- SLE
- Sjögren’s syndrome
- Primary biliary cholangitis
- Hyperthyroidism
- Sickle cell anaemia
- Marfan’s syndrome
Presentation of T1 renal tubular acidosis
- failure to thrive
- recurrent UTI
- rickets/osteomalacia
- muscle weakness
- arrhythmia due to low k+
causes of type 2 renal tubular acidosis
- inherited
- MM
- Fanconi’s syndrome
Mx of renal tubular acidosis
bicarbonate
oral KCL 3-3.5 or IV KCL <3
What is Haemolytic uraemic syndrome
- thrombosis in small BVs
- triggered by E.coli 0157 or Shigella
- children post gastroenteritis
triad of HUS
- microangiopathic haemolytic anaemia (RBC destruction)
- AKI
- thrombocytopenia
presentation of HUS
- bloody diarrhoea
- renal failure
- fever, abdo pain
Mx of HUS
- Supportive (Fluids, blood transfusion and dialysis if required)
- plasma exchange
- eculizumab
what is rhabdomyolysis
SM breaking down releasing:
- myoglobin
- potassium
- phosphate
- CK
causes of rhabdomyolysis
- prolonged immobility
- rigorous exercise
- crush injury
- seizure
- statins
Sx of rhabdomyolysis
- muscle pain, weakness and swelling
- reduced urine
- red/brown urine
- fatigue and confusion
- N&V
Mx of rhabdomyolysis
IV fluids mainstay
+ Iv sodium bicarbonate and mannitol if necessary
types of hyperkalaemia
normal 3.5-5.3
mild: 5.4-6
moderate 6-6.5
severe >6.5
causes of hyperkalaemia
- AKI
- CKD
- rhabdomyolysis
- adrenal insufficiency
- tumour lysis syndrome
- aldosterone antagonists (spironolactone)
- ACEi
- AIIRB
- NSAID
ECG changes assoc with hyperkalaemia
- tall tented T waves
- flat/absent p waves
- prolonged PR
- broad QRS
Mx of hyperkalaemia
Treat pt with severe hyperkalaemia (≥ 6.5 mmol/L) or with ECG changes:
- 10ml 10% IV calcium gluconate (stabilist cardiac muscle)
- 100ml 20% dextrose and 10units insulin (drive potassium into cells and prevent hypoglycaemia)
- nebulised salbutamol useful adjunt
- oral calcium resonium
- sodium bicaronate
- haemodialysis = severe
what is polycystic kidney disease
- AD and AR types. AD is more common
- PKD1 gene on Chr16 and PKD2 gene on Chr4 affected
- 10% of cases of CKD
- 2/3rds require renal replacement therapy
- Imaging USS can do MRI later
Presentation of polycystic kidney disease
MISHAPES
- abdo Mass
- Infected cysts and increase BP
- Stones
- Haematuria
- Aneurysms (berry)
- Polyuria and nocturia
- extra renal cysts (ovary, spleen, pancreas, prostate)
- systolic murmur (mitral regurg due to mitral valve prolapse)
complications of polycystic kidney disease
- Chronic loin/flank pain
- Hypertension
- Gross haematuria can occur with cyst rupture
- Recurrent UTIs
- Renal stones
- ESRF occurs at roughly 50yr
Mx of polycystic kidney disease
- Tolvaptan slows cyst dvlpt in AD
- antihypertensive
- analgesia
- Abx
- drainage
- dialysis and transplant
Causes of hyaline casts on urine MC&S
- normal
- after exercise
- loop diuretics
causes of chronic kidney disease that present with bilaterally enlarged kidneys on ultrasound
- HIV-associated nephropathy
- AD polycystic kidney disease
- diabetic nephropathy (early stages)
- amyloidosis
Causes of metabolic acidosis
Normal anion gap
- GI bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula
- renal tubular acidosis
- drugs: e.g. acetazolamide
-ammonium chloride injection
- Addison’s disease
Raised anion gap
- lactate: shock, hypoxia
- ketones: diabetic ketoacidosis, alcohol
- urate: renal failure
- acid poisoning: salicylates, methanol
cause of metabolic alkalosis
- vomiting / aspiration (e.g. peptic ulcer leading to pyloric stenos, nasogastric suction)
- diuretics
- liquorice, carbenoxolone
- hypokalaemia
- primary hyperaldosteronism
- Cushing’s syndrome
- Bartter’s syndrome
- congenital adrenal hyperplasia
causes of respiratory acidosis
- COPD
- decompensation in other respiratory conditions e.g. life-threatening asthma / pulmonary oedema
- sedative drugs: benzodiazepines, opiate overdose
causes of respiratory alkalosis
- hyperventilation
- pulmonary embolism
- salicylate poisoning
- CNS disorders: stroke, subarachnoid haemorrhage, encephalitis
- altitude
- pregnancy
Hypocalcaemia is an indication that kidney disease is chronic or acute?
chronic
indication of Alport Syndrome
renal failure, sensorineural hearing loss and ocular abnormalities develop in a child
Post renal transplant mx of low urine output, with tachycardia and relative hypotension
fluid challenge, probably just hypovolaemic
causes of acute interstitial nephritis
drugs: the most common cause, particularly antibiotics
- penicillin
- rifampicin
- NSAIDs
- allopurinol
- furosemide
systemic disease: SLE, sarcoidosis, and Sjogren’s syndrome
infection: Hanta virus , staphylococci
features of acute interstitial nephritis
- fever, rash, arthralgia
- eosinophilia
- mild renal impairment
- hypertension
- Eosinophilic casts in urine
