Renal Flashcards
AKI
- acute reversible reduction in renal function
- GFR declines -> failure to maintain fluid, electrolyte, acid-base homeostasis
- reduced UO, fluid overload, rise in K, urea, creat
AKI Dx criteria
- Rise in creatinine >25umol/L in 48hrs
- Rise in creatinine >50% in 7d
- UO less than 0.5ml/kg/hr over >6hrs
AKI stages
Look up diagram
AKI causes
Pre-renal
- low volume - D+V, burns, haemorrhage….
- decreased CO - MI, cardiogenic shock, HF
- vasodilation - sepsis, drugs
- renal hypoperfusion - NSAIDs, ACEi, ARB…
- flow obstruction - ischaemia, atherosclerosis, RAS
Renal
- ATN, glomerulonephritis, AIN, infection, sarcoidosis, HUS, rhabdo, NSAIDs, ACEi, gent, contrast, methotrexate, vasculitis
Post-renal
- stone, malignancy, stricture, clot
- pelvic malignancy, BPH
- neurogenic bladder
AKI Px
- asym
- reduced UO
- pulm / peripheral oedema
- arrhythmias
- uraemia - pericarditis / encephalopathy
- sx of cause
AKI Ix
- U/E
- urine dip
- fluid balance
- renal USS
All patients should get urinalysis
AKI Mx
- tx cause
- IV fluids
- stop worsening meds
- adjust renally-excreted meds
- tx electrolytes
- dialysis
Acute tubular necrosis (ATN)
- death of renal tubular epithelial cells
- ischaemic - hypoperfusion - shock, sepsis
- nephrotoxins - eg gentamicin, radiocontrast, rhabdo (myoglobin)
Px
- AKI
- muddy brown casts in urine
Acute interstitial nephritis (AIN)
- Acute inflammation of renal tubule-interstitium
Cause
- meds
- systemic disease, eg SLE, sarcoidosis
- infection
Px
- fever, rash, arthralgia
- eosinophilia
- mild renal impairment, HTN
Ix
- urine - sterile pyuria, white cell casts
Tubulointerstitial nephritis with uveitis (TINU)
- usually young females
Px
- fever, wt loss, painful red eyes
Ix
- urinalysis - leucocytes + protein
CKD
Chronic kidney function reduction - permanent + progressive
CKD causes
- diabetic nephropathy
- HTN
- Meds - NSAIDs, lithium
- glomerulonephritis
- PKD
- chronic pyelonephritis
CKD Dx criteria
> 3mo of either:
- eGFR <60
- urine albumin:creatinine ratio (ACR) >3mg/mmol
CKD classification by eGFR
1 - >90
2 - 60-89
3a - 45-59
3b - 30-44
4 - 15-29
5 - <15
CKD Px
- asym
- fatigue
- pallor
- foamy urine - proteinuria
- nausea
- anorexia
- pruritis - uraemia
- oedema
- polyuria
- HTN
- N+V
- peripheral neuropathy - vit/mineral imbalance
CKD Ix
- ECG - K
- Bloods - U/E, phosph, Ca, FBC
- urine albumin:creatinine ratio (ACR)
- urine dip + MC+S
- renal USS
- BP, HbA1c, lipids
- Kidney Failure Risk Equation
- Kidney biopsy
CKD Mx
- tx cause
- ACEi / ARB
- SGLT-2 inhibitor - dapagliflozin
- exercise, wt loss, stop smoking
- atorvastatin
- ESRF - dialysis, renal transplant
- review meds
CKD Cx
- anaemia
- CKD mineral and bone disorder (CKD-MBD)
- metabolic acidosis - oral sodium bicarb
- CV disease
- uraemia - lethargy, itch, anorexia, confusion, pericarditis
- peripheral neuropathy
- ESRF
Anaemia in CKD
- lack of EPO production -> fewer RBCs
- normocytic, normochromic
Mx
- oral / IV iron
- EPO
CKD-MBD
- high serum phosph, low vit D, low serum Ca
- kidneys secrete less phosphate, vit D not activated by kidneys (Ca not reabsorbed by kidneys, nor absorbed by gut), PTH secreted due to low Ca, increased bone turnover, osteosclerosis
Ix
- spinal XR - rugger jersey spine
Mx
- low phosph diet
- phosph binders - Ca based / can use sevelamer
- active vit D - calcitriol
- Ca in diet
- bisphosphonates for osteoporosis
Haemodialysis
- regular filtration of blood through dialysis machine
- blood access via AV fistula / tunnelled cuffed catheter
- anticoagulate with citrate / heparin
Indications for short-term dialysis
A - acidosis - severe, not responding to tx
E - electrolyte abnormalities - eg tx-resistant hyperkalaemia
I - intoxication - OD
O - oedema - severe, unresponsive pulmonary oedema
U - uraemia sx - seizures, coma
Peritoneal dialysis
- filtration in pt’s abdo - inject dialysis solution into abdo cavity, draws waste products from blood, then drain
- continuous ambulatory / automatic (at night)
Cx
- peritonitis - add vanc / teic + ceftazidime to dialysis fluid
Renal transplant
- donor kidney matched based on HLA type A,B,C
- take life-long immunosuppression
Rejection
- Hyperacute (mins-hrs) - T2 hypersensitivity - pre-existing ABs - widespread thrombosis of graft vessels - take graft out
- Acute graft failure (<6mo) - cytotoxic T cells, reversible with steroids, immunosuppressants
- Chronic graft failure (>6mo) - AB / cell mediated
Glomerulonephritis
- inflammation of glomeruli
Nephritic syndrome
- inflammation of kidneys - haematuria, oliguria, proteinuria <3g/24hrs, fluid retention/oedema