What is AKI?
Syndrome of reduced renal function occurring over hrs to days. It causes failure of fluid, electrolyte, and acid-base homeostasis.
Define AKI (3)
Rise in creatinine >26umol/L within 48hrs.
Rise in creatinine >1.5x baseline within 7 days
Urine output <0.5 ml/kg/hr >6 consecutive hrs.
Risk factors for AKI (9)
Pre-existing CKD Age Male Diabetes CVD Malignancy Chronic liver disease Surgery
Pre-renal causes of AKI:
- Reduced vascular volume (4)
- Reduced CO (1)
- Systemic vasodilation (1)
- Renal vasoconstriction (3)
Reduced perfusion to kidneys!!!
- Haemorrhage. D+V. Burns. Pancreatitis.
- Cardiogenic shock
- Sepsis
- NSAID, ACEi, hepatorenal syndrome
Renal causes of AKI
- Kidney
- Vessels
Intrinsic renal disease!!!
- Glomerulonephritis. Acute tubular necrosis
- Vasculitis. HUS. TTP
Post renal causes of AKI (5)
Renal tract: Renal stone, malignancy, stricture.
Extrinsic compression: Pelvic malignancy, BPH.
Treatment system plan: (6)
- Rule out life-threatening complications.
- ABCDE assessment
- If hypovolaemic = give fluids.
- Monitor
- Investigate.
- Support
Name the 3 life threatening complications to rule out?
Hyperkalaemia
Sepsis
Fluid overload - pulmonary oedema
What things to monitor? (5)
- Fluid balance
- Potassium
- vital signs
- lactate if septic
- Daily Creatinine.
What things to investigate? (5)
- Urine dipstick - heamaturia + proteinuria = intrinsic renal disease.
- FBC - platelets for heamolysis (HUS/ TTP)
- LFT - hepatorenal syndrome (hypoalbuminaemia).
- Renal USS - no cause is found
- Intrinsic renal disease = immunoglobulins, autoantibodies, paraproteins.
What things to support? (4)
- Tx sepsis
- stop DAMN drugs
- Medication review - check dosages.
- Avoid radiological contrast.
What information to gather during clinical exam and Ixs? (10)
- Creatinine trend.
- K
- Lactate.
- FBC
- Urine dipstick
- NEWS score.
- Fluid input + output
- O/e findings - hypo/hypervolaemia
- Co-morbidities
- Drugs - when and nephrotoxic?
Features of hypovolaemia? (4)
Low BP
Low urine volume
Increased Heart rate
Daily weight loss
Features of hypervolaemia (5) and Tx:
Increased BP Increased JVP Lung crepitations Peripheral oedema S3 sound. Tx: Oxygen, fluid restriction, diuretics is symptomatic
ECG features of hyperkaelamia? (4)
Tall tented T waves
Increased PR interval
Small/absent P waves
Wide QRS complex
Tx of hyperkalaemia? (2)
10ml of 10% calcium chloride over 10-15 mins IV insulin (drive K into cells) -> 2nd line - salbutamol -> 3rd line - renal replacement therapy.
Indications for renal replacement therapy?
Fluid overload not responding to Tx
Prolonged/severe acidosis (metabolic acidosis)
Persistent/ recurrent high potassium
uraemic pericarditis/ encephalopathy.
Treatment:
- Pre-renal
- Renal
- Post renal
- Fluids + Tx sepsis
- Urine dipstick, biopsy, and refer to specialist
- catheter, nephrostomy, urological intervention
