Renal Flashcards
Functions of the kidney (7)
Regulation of blood volume Regulation of blood pressure Acid-base balance Electrolyte balance Production of Red blood cells Synthesis of Vitamin D – Bone metabolism Excretion of water-soluble waste products – Filter
Define AKI
“A rapid decline in renal function over hours or days”
How is AKI measured
Urea and creatinine
Easiest way to recognise AKI
You stop peeing
Main three ways AKI causes problems and what are they
Fluid oliguria, volume overload
Electrolyte hyperkalaemia
Acid-base metabolic acidosis
Define CKD
Impaired renal function for >3 months based on
abnormal structure or function, or
GFR <60ml/min for >3m
+/- evidence of kidney damage
What is used to risk stratify AKI
KDIGO
Signs of AKI (5)
Hypertension
Distended bladder
Dehydration - postural hypotension
Fluid overload (in heart failure, cirrhosis, nephrotic syndrome) - raised JVP, pulmonary and peripheral oedema
Pallor, rash, bruising (vascular disease)
Main 4 symptoms of AKI
Oliguria/anuria NOTE: abrupt anuria suggests post-renal obstruction Nausea/vomiting Dehydration Confusion
What is the pathological mechanism behind pre-renal AKI
Inadequate Perfusion
What are the 4 mechanisms that can cause prerenal AKI
Hypovolaemia
Systemic vasodilation
Decreased cardiac output
Intrarenal vasoconstriction
What can cause hypovolaemic AKI (7)
Renal loss from diuretic overuse, osmotic diuresis (e.g., diabetic ketoacidosis)
Extrarenal loss from vomiting, diarrhea*, burns, sweating, blood loss
What can cause systemic vasodilatory AKI (2)
Sepsis*, neurogenic shock
What can cause decreased CO AKI (2)
HF, MI
What can cause intrarenal vasoconstrictive AKI (3)
Cardiorenal syndrome, hepatorenal syndrome
ACEi with renal artery stenosis
What are the four main mechanisms behind renal AKI
Acute tubular necrosis
Glomerulonephritis
Interstitial nephritis
Vascular obstruction
What can cause renal AKI through acute tubular necrosis (3)
Ischemia, drugs, toxins (paracetamol, NSAIDs, ACE-I, contrast, myoglobinuria in rhabdomyolysis etc.)
Which drugs can cause renal AKI through acute tubular necrosis (3)
paracetamol, NSAIDs, ACE-I,
Which toxins can cause renal AKI through acute tubular necrosis (2)
contrast, myoglobinuria in rhabdomyolysi
Main way of getting glomerulonephritis?
Postinfectious
What can cause renal AKI through interstitial nephritis (3)
Drugs
Infection
Infiltration
What can cause renal AKI through vessel obstruction (3 (+3))
Thrombosis
vasculitis
haemolytic microangiopathy (HUS, TTP, DIC)
What are the 3 main mechanisms behind post-renal AKI
Luminal
Mural
Extrinsic compression
What can cause luminal post-renal AKI (2)
Stones, clots