RENAL: AKI Flashcards
What blood tests may you order to investigate a patient’s renal function? (For each you can think of, state what you might be looking for. )
FBC - signs of anaemia, infection
Haematinics - iron, folate, b12 deficiency
U&E - Potassium, urea, creatine, bicarbonate
Bone profile - Calcium, phosphate, PTH, Alkaline Phosphatase, Albumin
CRP - Infection, Inflammation
HbA1c - diabetic control
What urinary tests may you order to investigate a patient’s renal function? (For each you can think of, state what you might be looking for. )
Urine dipstick - infection (leukocytes, nitrites), any pathology of glomerulus (blood, protein)
Urine protein:creatinine ratio - quantifies amount of protein in urine
Urine albumin:creatinine ratio - quantifies amount of albumin
Urine microscopy, culture and sensitivity (MC&S)
What imaging may you order to investigate a patient’s renal function?
US KUB - good for peri-nephric (i.e. around the kidney) collections, size of the kidneys, corticomedullary differentiation, hydronephrosis
What would VBG show for metabolic acidosis?
pH would be low
Bicarb would be low
pCO2 would be normal (maybe low if compensation)
What would VBG show for metabolic alkalosis?
pH would be high
Bicarb would be high
pCO2 would be normal
What are specific causes of metabolic acidosis? (Split into causes of lactic acidosis, ketoacidosis, GI losses, renal losses and toxins)
Lactic acidosis - due to sepsis, anaerobic exercise, organ ischaemia
Ketoacidosis - diabetic, starvation, alcohol abuse
GI losses of bicarb - diarrhoea
Renal losses of bicarb - renal tubular acidosis, Addison’s
Toxins - Aspirin, Isoniazid (used in TB), see others on pg5 of booklet
Why may a patient have a metabolic acidosis? (HINT: 2 main overarching reasons)
Due to having increased acid OR acidosis due to reduced alkali
What are RF for AKI?
DM
CKD
IHD, CCF (congestive heart/cardiac failure),CVD
Liver disease
Elderly 75+ (Z2F says 65+)
Sepsis
Cognitive impairment
Nephrotoxic Meds - ACEi, ARBs, NSAIDs, Abx
Use of contrast medium e.g. during CT scans
How many stages of AKI are there?
3
How can causes of AKI be grouped?
Pre renal
Intrinsic
Postrenal
Name pre renal causes of AKI
Z2F: Dehydration, Hypotension(shock), HF
Renal Booklet: Hypovolameia
Decreased cardiac output
Decreased effective circulating volume - in CCF, Liver failure
Impaired renal autoregulation - due to NSAIDs, ACEi, ARBs, Cyclosporine
Name intrinsic/renal causes of AKI
Z2F: Glomerulonephritis, Interstitial nephritis, Acute Tubular necrosis
Renal booklet: Acute glomerulonephritis
Ischamia
Sepsis / infection
Vasculitis
Malignant HTN
Nephrotoxins - e.g contrast, haemolysis, cisplatin, aminoglycosides e.g. gentamicin
Name post renal causes of AKI
Z2F: kidney stones, masses, ureter or urethral strictures, BPH, prostate cancer
Renal booklet: Bladder outlet obstruction e.g. renal calculi, BPH
Pelvoureteral obstruction
What is the most important investigation in suspected AKI?
URINE DIP - look for abnormal proteins and blood
(This is according to renal booklet)
Z2F: Urinalysis - protein and blood (for acute nephritis), leucocytes and nitrites (for infection), glucose (for diabetes)
What investigations would you want to do in patient with suspected AKI?
Urine dip
FBC, U&E, LFTs, bone profile, CRP
Urine PCR, Urine MC&S,
USS KUB - look for obstruction
Potential presenting complaint in AKI
Symptoms: Nausea, vomiting, diarrhoea, tiredness/fatigue, changes to urine colour
Reduced urine output.
sepsis
How is AKI managed?
Treat underlying cause (prerenal, itrinsic, post renal). Send off investigations
Stop any nephrotoxic agents
Dehydrated? IV fluids
Overloaded? Diuretics
Monitor urine output (catheterise if needed) and daily bloods
Avoid hyperglycaemia
What are indications for renal replacement therapy?
Hyperkalaemia even after medical therapy
Metabolic acidosis even after medical therapy
Fluid overload which is not helped by diuretics
Uraemic pericarditis
Uraemic encephalopathy
Intoxications
What is uraemia?
High urea.
Waste products that should be removed via urination accumulate in the blood. This is due to reduced kidney function
What are signs of uraemic encephalopathy?
Vomiting, confusion, drowsiness, reduced consciousness
Define AKI
An acute drop in kidney function
How is AKI diagnosed?
By measuring the serum creatinine
What are NICE criteria for AKI?
Rise in creatinine of 25< micromol/L in 48hrs
Rise in creatinine of 50%< in 7 days
Urine output of <0.5ml/kg/hr for more than 6 hours
What are complications of AKI?
Hyperkalaemia
Fluid overload, HF, pulm oedema
Metabolic acidosis
Ureaemia
