Renal Flashcards
What is AKI
Acute drop in kidney function
Diagnosed by measuring serum creatinine
Increased morbidity and mortality
What is the NICE criteria for AKI
Rise in creatinine in .25 micromol/L in 48 hrs
Rise in creatinine of > 50% in 7 days
Urine output of < 0.5 ml/kg/hr for > 6 hrs
What are the risk factors for AKI
Consider in anyone with an acute illness or having surgery
CKD
Heart failure
Diabetes
Liver disease
Sepsis
> 65
Cognitive impairment
Nephrotoxic drugs (NSAISs, ACE inhibitors, antibiotics)
Use of contrast
What are the pre-renal causes of AKI
Most common cause of AKI
Due to inadequate blood supply to kidneys
Dehydration
Hypotension (shock)
Heart failure
What are the renal causes of AKI
Glomerulonephritis
Intestinal nephritis
Acute tubular necrosis
What are the post-renal causes of AKI
Obstruction of outflow of urine (backpressure to kidneys, obstructive uropathy)
Kidney stones
Masses
Ureter/urethral strictures
Enlarged prostate/prostate cancer
What investigations are needed for AKI
Urinalysis (leukocytes and nitrates, proteins, blood, glucose)
Ultrasound of urinary tract
What is the management for AKI
Avoid/stop nephrotoxic drugs
Adequate fluid intake/fluid rehydration
Relieve obstruction
May need dialysis
What are the indications for renal replacement therapy
Hyperkalaemia due to medical therapy
Metabolic acidosis due to medical therapy
Fluid overload due to diuretics
Uraemic pericarditis
Uraemic encephalopathy (vomiting, confusion, drowsiness, reduced consciousness)
Intoxications (lithium, methanol)
What are the complications of AKI
Hyperkalaemia
Fluid overload
Heart failure
Pulmonary oedema
Metabolic acidosis
Uraemia (encephalopathy, pericarditis)
What is CKD
Chronic reduction in kidney function
Usually permanent and progressive
What are the causes of CKD
Diabetes
Hypertension
Age-related decline
Glomerulonephritis
Polycystic kidney disease
Medications (NSAIDs, PPIs, lithium)
What are the risk factors for CKD
Increasing age
Hypertension
Diabetes
Smoking
Nephrotoxic drugs
How might CKD present
Usually asymptomatic
Pruritus
Loss of appetite
Nausea
Oedema
Muscle cramps
Peripheral neuropathy
Pallor
Hypertension
What investigations are needed in CKD
U&Es (measure eGFR, 2 tests 3 months apart)
Proteinuria (urine albumin:creatinine, > 3 mg/mmol is significant)
Haematuria (urine dip, investigate for malignancy)
Renal ultrasound (if have accelerated CKD, haematuria, family history of polycystic kidney disease, evidence of obstruction)
What are the stages of CKD
G score (based on eGFR):
- G1: > 90
- G2: 60 - 89
- G3: 45 - 59
- G4: 15 - 29
- G5: < 15 (end stage renal failure)
A score (based on albumin:creatine):
- A1: < 3 mg/mmol
- A2: 3 - 30 mg/mmol
- A3: > 30 mg/mmol
Need to have at least eGFR < 60 or proteinuria to have CKD
What are the complications of CKD
Anaemia
Renal bone disease
Cardiovascular disease
Peripheral neuropathy
Dialysis-related problems
Hyperparathyroidism
Hypertension
Malnutrition
Dyslipidaemia
What are the NICE guidelines for referral to a specialist in CKD
eGFR < 30
ACR > 70 mg/mmol
Accelerated progression (eGFR decrease by 15 (or 25%) in 1 year)
Uncontrolled hypertension (despite using > 4 antihypertensives)
What is the management for CKD
Treat underlying cause
Slow progression (optimise diabetes/hypertension, treat glomerulonephritis, monitor bloods)
Reduce risk of cardiovascular disease (statins, control BP, improve diabetic control, lifestyle modifications)
Reduce risk of complications (exercise, weight loss, smoking cessation, reduce salt, atorvastatin)
Treat complications
How is hypertension treated in CKD
ACE inhibitors (1st line for CKD)
Target < 140/90
Monitor serum potassium (CKD and ACE inhibitors cause hyperkalaemia)
What is anaemia of CKD
CKD causes from in EPO
Management: exogenous EPO, blood transfusions
Treat iron deficiency before giving EPO
What is renal bone disease
Features: osteomalacia, osteoporosis, osteosclerosis
X-ray changes (‘rugger jersey spine’
Management: vit D supplements, low phosphate diet, bisphosphonates
What are the indications for acute dialysis
AEIOU
Acidosis (severe and not responding to treatment)
Electrolyte abnormalities (severe and unresponsive hyperkalaemia)
Intoxication (overdose)
Oedema (severe and unresponsive pulmonary oedema)
Uraemia (seizures, reduced consciousness)
What are the indications for long term dialysis
End stage renal disease (CKD stage 5)
If any of the acute indications continue long term
What are the options for maintenance dialysis
Continuous ambulatory peritoneal dialysis
Automated peritoneal dialysis
Haemodialysis
What is peritoneal dialysis
Use peritoneal membrane as filtration membrane
Dialysis solution (dextrose) added to peritoneal cavity
Ultrafiltration occurs from blood
Involves a tenckhoff catheter
Continuous ambulatory peritoneal dialysis/automated dialysis
Complications: bacterial peritonitis, peritoneal sclerosis, ultrafiltration failure, weight gain, psychological effects, hydrothorax
What is haemodialysis
Usually 4 hours 3 days a week
Tunnelled cuffed catheter/arterio-venous fistula