AKI Flashcards
Can you use eGFR to describe AKI?
No! eGFR formula assumes creatinine in steady state, not valid if changing. eGFR is not safe to use in drug dosing in AKI
Which two measurements are key to assessing AKIs?
Serum creatinine and urine output
How can causes of AKIs be divided?
Intrinsic, pre-renal, post-renal
Which category of cause is responsible for all AKIs?
Pre-renal
Name three examples of intrinsic causes of AKIs
- Acute tubular injury- rhabdo, nephrotoxins, haemoglobinuria
- Tubulointerstitial injury
- Glomerulonephritis
- Myeloma
- Vasculitis
Name three examples of nephrotoxins
Iodinated contrast, NSAIDs, gentamicin
Name three examples of pre-renal causes of AKIs
- Sepsis
- Hypovolaemia
- Hepatorenal syndrome
- Cardiac failure
- Hypotension
Name three causes of hypovolaemia
- Haemorrhage
- Burns
- Vomiting/diarrhoea
- Diuretics
Which three antibiotics should you be wary of in AKIs?
Trimethoprim, nitrofurantoin, gentamicin
How does trimethoprim affect the kidney?
Increases creatinine
Why should you be cautious with nitrofurantoin when there is an AKI?
Not excreted in urine if creatinine clearance <30 therefore inadequate urine concentration to treat UTI and risk of toxicity
Name 5 clinical assessments that can be conducted to determine whether patient is hypovolaemia, euvolaemic, or hypervolaemic
- Oedema
- JVP
- Mucous membranes
- Skin turgor
- Chest auscultation
- Urine output
- Weight
- BP
Name four investigations for AKIs
- Urinalysis- blood/protein
- Bicarbonate
- Urine protein:creatinine ratio (uPCR)
- Glomerulonephritis screen
- Renal USS (within 24 hr unless clear signs of improvement)
Name four components of the glomerulonephritis screen
- ANCA (MPO/PR3)
- ANA
- Anti-GBP
- RF
- Myeloma screen
Name three post-renal causes of AKI
- Kidney stones
- BPH
- Tumours
- Retroperitoneal fibrosis
At what kidney failure stage should you refer to renal?
Stage III
What are ECG features of hyperkalaemia?
Hypertented T waves, absent P waves, increased PR interval, broad QRS, BBB
How to stage AKI?
1-3, compare current Cr to baseline, if 1.5-2x greater then stage 1, if 2-3x greater then stage 3, if >3x then stage 3. Note different staging system to CKD
What are clinical signs (not symptoms) of CKD?
Uraemia, anaemia, vit D deficiency, K+, acidosis
What is the management of CKDs?
EPO, fluid resus, ACEi, dietary advice
What are the five indications for commencement of dialysis?
AEIOU: acidosis, electrolyte, ingestion, overload (HF), uraemia
What are three ways of defining an AKI?
- increase in SCr by >0.3 mg/dl within 48 hr
- increase in SCr to >1.5 x baseline
- Urine volume <0.5 ml/kg/hr for 6 hr
What are the stages of AKI?
1-3 stage
- 1.5-1.9 baseline SCr
- 2-2.9
- > 3
Why is eGFR not used in AKIs?
serum creatine needs to be in steady state ~ HbA1C in diabetes
What are the pre-renal causes of AKI?
- volume depletion- vomiting, diarrhoea, diuretics, burns, haemorrhage
- Cardiac pump failure
- Sepsis
- Medications
- Hepatorenal syndrome (rare)
What are the intrinsic causes of renal AKI based on site?
glomerulus- glomerulonephritis
tubules- acute tubular necrosis, rhabdo
renal vessels- renal artery stenosis, occlusion, renal vein thrombosis
Which symptoms are associated with intrinsic causes of AKI?
rashes, painful eye (ANCA), paresthesia, foot drop, frank haematuria, swelling
Investigations for AKI?
U+Es urine dip ABG/VBG Renal tract ultrasound Glomerulonephritis screen Myeloma screen Renal biopsy
What are the complications of AKI?
electrolyte disturbance
fluid overload
metabolic acidosis
uraemic
What is the management of AKI?
correct hypovolaemia treat acute complications (hyperkalaemia, acidosis) r/v medications Optimise cardiac function Monitor fluid output Search for infections
How can you assess volume status?
Pulse/BP/SpO2 Urine output Mucous membranes Weight Peripheral oedema/JVP Loss of skin turgor
How can you distinguish AKI from CKD if patient has never undergone U+E blood testing?
renal size on US- CKD nephrons will appear smaller and cystic
anaemia- anaemia of chronic disease
hyperparathyroidism- association with CKD
In which condition associated with AKI can you develop a petechial rash?
SLE, vasculitis
In which condition associated with AKI can you develop a purpuric rash?
thrombotic thrombocytopenic purpura, systemic vasculitis, henoch schloenlein purpura
Which poisons result in renal replacement therapy?
BLAST it out Barbiturates Lithium Alcohols Salicylates Theophyline
What level of creatinine kinase would you suspect rhabdomyolisis?
very high, 10,000’s
