What two things are measured in AKI and help to define AKI? What is the main clinical clue?
- REDUCED URINE OUTPUT is the main clinical clue (consider AKI in anyone with reduced urine output)
What are the magic numbers in AKI
What patients does this not really work for?
STAGE 1: Creatinine increased by 26umol (or more) from baseline within 48 hours or 150% in 7 days (risk)
STAGE 2: 200% (injury)
STAGE 3: Creatinine rise to 354umol or increase of 300% (failure)
**CKD patients have higher creatinine, so these values are for healthy patients
What is creatinine?
Limitations of creatinine?
-Creatinine is a breakdown of skeletal muscle that is excreted by the kidneys (majority glomerulus so good estimate of filtration)
Creatinine=most useful marker, however affected by:
• Muscle mass
•eGFR can fall to half before creatinine rises past upper limit
• Dilution
What are the most common pre-renal causes of AKI?
What can hypo perfusion lead to?
PRE RENAL CAUSES AKI (the most common-70%)
-Nearly always due to HYPOPERFUSION of the kidney
•Hypovolaemia (burns, heamorrgae, D+V, pancreatitis)
•Reduced cardiac output (heart failure/MI)
•Distributive shock sepsis (vasodilation) or anaphylaxis
•Altered blood flow to kidneys (NSAIDs/ACEis/renal artery stenosis/hepatorenal syndrome)
*Hypoperfusion can lead to acute tubular necrosis (ATN) (which is an intra-renal cause)
What are some common intra-renal causes of AKI?
remember they can e split up into 3 parts
INTRA-RENAL CAUSES AKI (20%) 1) Glomerulus •Glomerulonephridities (e.g. SLE/HSP) •ATN (Acute tubular necrosis-often from pre renal) 2) Interstitial •Nephrotoxic drugs/infection/infiltration (e.g. sarcoid/myeloma free light chains) 3) Vessels •Vasculitis/HUS/TTP/DIC/malignant HTN
What are some common post-renal causes of AKI?
can either have within renal tract or extrinsic
POST-RENAL CAUSES AKI
-Bilateral obstruction of urinary flow out of the kidneys (leading to hydronephrosis)
Within renal tract
Extrinsic compression
What are some risk factors for developing AKI?
Risk factors for AKI
History, Examination, Investigations for AKI?
AKI
History
-have you been ill recently
-have you had any recent scans
Examination
Investigations
How should you initially manage a patient with AKI?
AKI MANAGMENT
ABCDEG> treat sepsis if found then USTOP
USTOP
What common drugs are nephrotoxic?
AL DIAMOND
Antihypertensives e.g. ACEi, ARB, BB, CCB, AB
Lithium
Diuretics (especially potassium sparing)
Intravenous contrast /immunosupresants
Antibiotics - gentamicin (aminoglycosides) + nitrofurantoin
Metformin
Opioids
NSAIDs
Digoxin (aggravates hyperkaleamia)
What are drugs may increase risk of urinary retention?
Drugs that increase risk of urinary retention
How would a patient in urinary retention present?
What investigations should you do for someone having urinary retention?
Urinary retention
Investigations:
Bloods: FBC, UsEs, Glucose, PSA
Imaging: USS renal, CT pelvis/abdo/ MRI/CT head look for neuro cause if unexplained
Who is acute urinary retention more common in and why?
What are some common causes of acute urinary retention?
What are some causes of urinary retention in women?
Urinary retention
Urinary retention in women
What are some specific things you’d want to check on history and examination in urinary retention?
URINARY RETENTION
-Exam- do PNS exam, PR (anal tone and also prostate) and pre/post BLADDER SCAN
How should acute urinary retention be managed?
Urinary retention
Testing urine
-Once urine has been passed then DIP IT for infection and treat that
How will renal colic present?
Intermittent flank or loin pain that might also travel down to the groin
SEVERE PAIN that comes and goes in waves - this pattern of pain is due to ureteric peristalsis
Might also have urinary symptoms of:
- Anuria, dysuria, increased frequency, urgency, suprapubic tenderness, changes in smell or colour of urine, haematuria, sweating, fever, N&V
What is a common cause of renal colic?
KIDNEY STONES (Sweaty, N&V, and excruciating pain will predominate)
How should you investigate someone with renal colic pain?
KUB USS Urine dip - blood leucocytes Pregnancy test in women CT Bloods: FBC, U&E, WCC, CRP
How should someone with renal colic be managed initially?
Painkillers (might need IV)
FLUIDS - really important to keep patient hydrated.
Shock therapy can break down stones to make them easier to pass
How will testicular torsion present?
What will appear like on examination?
O/E:
Who is testicular torsion most common in?
How should testicular torsion be investigated?
How do we define a UTI?
UTI