+ Causes of Acute Kidney Injury Amy Livesey

+ Overview Why Acute Kidney Injury? Definition Recap of types of AKI Causes of Acute Kidney Injury How to recognise AKI clinically Summary

+ Why Acute Kidney Injury? 8.10 Acute renal failure By the end of phase II students should be able to: Recognise acute renal failure, distinguish is from chronic renal failure and relate the changes to the underlying pathophysiology Act to prevent the condition as far as possible Initiate investigation and management for the patient Discuss the prognosis of acute renal failure

+ Why Acute Kidney Injury? 8.10 Acute renal failure Kidney Injury By the end of phase II students should be able to: Recognise acute renal failure, distinguish is from chronic renal failure and relate the changes to the underlying pathophysiology Act to prevent the condition as far as possible Initiate investigation and management for the patient Discuss the prognosis of acute renal failure

+ Definition Can anybody think of a succinct definition?

+ Definition Acute Kidney Injury is defined as: A significant deterioration in renal function, which is potentially reversible, over a period of hours or days.

+ Definition Renal Association criteria: Serum creatinine rises by ≥ 26µmol/L within 48 hours or Serum creatinine rises ≥ 1.5 fold from the reference value, which is known or presumed to have occurred within one week or urine output is 6 consecutive hours (oliguria)

+ Acute Kidney Injury (acute renal failure) Hours - weeks Chronic Kidney Disease recovery End stage renal disease (failure) Months - years Kidney Disease and Renal Failure

+ Causes of Acute Kidney Injury

+ Causes of AKI Normal urine output requires: 1. Adequate blood supply to the kidneys 2. Functioning kidneys 3. Unobstructed flow of urine from kidneys, down the ureters, into the bladder and out via the urethra.

+ Causes of AKI 1. Pre-renal 2. Intrinsic/ renal 3. Post-renal

+ 1. Pre-renal I.e. Inadequate blood supply to the kidneys Inadequate cardiac function Hypovolaemia Obstruction of arterial supply Drugs altering renal haemodynamics NSAIDs ACEi

+ 2. Intrinsic/ Renal I.e. Damage resulting in impaired kidney function 1. Tubular  Acute Tubular Necrosis (‘Muddy brown casts’ in urinalysis) 2. Glomerular  Glomerulonephritis 3. Interstitial  Interstitial nephritis (usually drug induced e.g NSAIDs, ABX) 4. Vascular  Vasculitis, emboli, Malignant HTN, DIC Infectious  Malaria, Legionnaires’ disease, Leptospirosis 6. Complex mechanism (!)  Multiple Myeloma

+ 3. Post-renal i.e. obstruction to urinary flow 1. Ureters (e.g Abdominal/pelvic mass compressing ureters, bilateral calculi, retroperitoneal fibrosis). 2. Bladder (e.g Neuropathic bladder, bladder tumour of calculi) 3. Uretha (e.g BPH, blocked catheter, prostate cancer, urethral stricture, trauma, infection)

+ How to recognise AKI clinically General pattern of acute kidney injury: Increase in K+ Increase in urea Increased creatinine Reduced pH Low BP Tachycardia Reduced urine output Weight loss Drugs: NSAIDs ACEI/ ARB Radio contrast Fever

+ Hopefully you can now all…. Have an idea of how to define AKD Know how to tackle answering a question about causes of AKI Pre-renal Renal Post-renal Be able to recognise AKI clinically