MM renal tutorial Flashcards
What is AKI
Decreased renal function
How is AKI measured?
Serum creatinine or urine output
How can you differentiate AKI from chronic kidney disease?
It occurs over days or hours
How many stages of AKI are there?
3
How should you measure creatinine?
Compare it to a patients baseline- younger patients will have different levels to older
What will AKI progress to?
Chronic kidney disease
What are the causes of AKI?
Pre renal
Renal
Post renal
What are pre renal causes of AKI? Why do they cause AKI?
All of them cause hypoperfusion of the kidneys:
Hypovolemia
Renal artery stenosis
Hypotension eg sepsis, heart failure, NSAIDs
What are post renal causes of AKI?
They can be internal eg renal calculi, urethral, stricture or external eg pelvic, malignancy and BPTT
What are renal causes of AKI?
Glomerular= glomerulonephritis, haemalytic, uraemic syndrom
Vascular= vasculitis
Tubular= acute tubular necrosis, multiple myeloma
Interstitial disease= acute interstitial nephritis
What is the most common cause of renal AKI?
Acute tubular necrosis
What is acute tubular necrosis?
Death of the epithelial cells that line the tubules in the kidney
How does AKI present?
Different symptoms depending on the cause but they may have symptoms of: Malaise Anorexia Vomiting Pruritis Drowsiness Oligouria Coma
What should you always ask if you suspect AKI?
Ask about medication (have they been started on any nephrotoxic drugs recently?)
Have they had any recent burns or surgery (can cause hypovolemia)
What is the usual cause of hypervolemia?
Iatrogenic
What are the complications of AKI and how do you remember them?
Remember them by thinking about the function of the kidneys and what would go wrong if these functions weren’t carried out. Use the pneumonic A WET BED:
A- maintaining ACID balance (if this isn’t done there will accumulation of acid)
W- maintaining WATER balance (if this isn’t done there is usually hypovolemia but can be hypervolemia too)
E- maintaining ELECTROLYTE balance (if this isn’t done you get hyperkalemia and high phosphates)
T- toxin removal (if this isn’t done you get uremia)
B- maintain BLOOD pressure (if this isn’t done you get hypertension because the kidney secretes renin)
What are complications of AKI?
Excess acid Hyper or hypovolemia Hyperkalemia High phosphates Uraemia
Progression to CKD
What investigations should you do if you suspect AKI?
Bloods= U+Es, LFTs, FBC (if you suspect an autoimmune cause you could test for those specific antibodies too)
Urinalysis
ECG
CXR
USS (if you think AKI is obstructive/ unsure of the cause)
Renal biopsy
How will hyperkalemia show up on an ECG
?
High T waves
How do you treat AKI?
Depending on the cause
How do you treat AKI that has arisen from nephrotoxic drugs?
Stop the drug treatment
How do you treat pre renal AKI?
Manage volume depletion
How do you treat renal AKI?
Refer to a specialist, likely do a renal biopsy
How do you treat post renal AKI?
Catheter, urological intervention
What should you monitor when treating someone with AKI?
Urea and electrolytes ABG Potassium levels Blood pressure Urea levels
What happens if you can’t control hyperkalemia or pulmonary oedema in an AKI pateint?
Use renal replacement therapy
What is given to treat hyperkalemia in AKI?
Calcium
IV dextrose and insulin
Salbutamol
Why is calcium given to treat hyperkalemia in AKI?
To prevent risk of cardiac arrythmia
Why is IV dextrose and insulin given to treat hyperkalemia in AKI?
To drive potassium into cells
Why is salbutamol given to treat hyperkalemia in AKI?
To increase the effects of the IV potassium and insulin
How would a metabolic acidosis from AKI be treated?
IV sodium bicarbonate
How is pulmonary oedema treated?
Oxygen
IV diamorphine
IV GTN
Frusemide
Why is IV diamorphine given to treat pulmonary oedema in AKI?
It relieves anxiety and breathlessness
What is the main investigation for chronic kidney disease?
Serum electrolytes, urea and creatinine
What is CKD?
Kidney damage (manifesting as proteinuria or hematuria) GFR <60 mL/min For 3 months (longer than AKI)
How many stages are there of CKD and how are they catagorised?
5
they are based on GFR
What is stage 1 of CKD?
Kidney damage with normal GFR
What are causes of CKD?
Glomerular= glomerulonephritis, diabetes, SLE
Vascular= hypertension, heart failure
Tubular/interstitial= interstitial nephritis, pyelonephritis, medication
Obstruction= kidney stones, BPH, multiple myeloma
Medication use= NSAIDs
Congenital= PCKD, alport syndrome
What are the 2 biggest causes of CKD?
Diabetes
Hypertension
How does CKD present?
It is cause specific, general symptoms of renal deterioration:
Pruritis Nausea and vomitting Anorexia Oedema Polyuria/ oligouria Shortness of breath (due to fluid) Bruising
What investigations should you do if you suspect CKD?
Bloods (creatinine is used to estimate GFR, check glucose to check for underlying diabetes, FBC, LFTs, calcium and phosphate)
Urinalysis (hematuria/proteinuria/ tubular cells)
CXR (to check for fluid overload)
Renal biopsy
Renal ultrasound is not usually done but can be
What is are the best initial investigations for renal patients?
Serum electrolytes, urea, creatinine (you want to check their GFR and this is the way to do it)
What is glomerulonephritis?
The inflammation of the glomeruli
What does glomerulonephritis lead to?
Nephritic or nephrotic syndrome
What are the 2 main symptoms of glomerulonephritis?
Haematuria
Proteinuria
What is the main symptom of nephritic syndrome?
Haematuria
How might patients describe haematuria?
Coca-cola coloured urine/ dark urine/ brown urine
What is the main symptom of nephrotic syndrome? Whats a good way to remember it?
Proteinuria
Remember nephrOtic syndrome= prOteinuria whereas as nephritic is more haematuria
Is oedema more associated with nephrotic or nephritic syndrome?
Nephrotic
What are the symptoms of nephritic syndrome?
Haematuria
Oligouria
Hypertension
Oedema