urogenital Flashcards
what forms the inguinal ligament
external oblique aponeurosis
what was the renal blood flow
Renal artery 🡪 interlobar artery 🡪 arcuate artery 🡪 interlobular artery 🡪 afferent arteriole 🡪 glomerular capillary 🡪 efferent arteriole 🡪 peritubular capillary around tubules
what is the standard GFR
125 ml/min
what was the criteria for a good GFR indicator like creatinine
freely filtered
not metabolised
not secreted
not reabsorbed
explain tubulo-glomerular feedback
macula densa cells is DCT dectect low levels of NaCl –> release prostaglandins to stimulate renin release and trigger RAAS to cause vasoconstriction of afferent arteriole
high levels of NaCl detected by macula densa –> signal to afferent arteriole to cause vasodilation
why does vasoconstriction of the afferent arteriole increase GFR?
because it increases HYDROSTATIC pressure so more capillary contents flow into bowman’s capsule
during renal filtration, the blood pressure in the glomerular capillaries (glomerular hydrostatic pressure) is the main driving force pushing fluids and solutes out of the blood and into the Bowman’s capsule. The opposing pressures from the Bowman’s capsule and the oncotic pressure within the glomerular capillaries work against this filtration to maintain a balance.
how do you measure GFR and state the formula
with creatinine or cystatin C
(creatinine urine conc. x urine flow)/plasma creatinine concentration
what are the components of the filtration barrier
Fenestrated capillaries
basement membrane
podocyte foot processes
what is the criteria to diagnose AKI
NICE criteria:
Rise in creatinine of >26 micromol/L in 48 hours
Rise in creatinine to ≥1.5 times baseline in a span of 7 days
Urine output of <0.5ml/kg/hr for >6 hours
what is AKI
Sudden decline in renal function over hours or days leading to a rise in serum creatinine and/or a fall in urine output
explain pre-renal, intra-renal and post-renal AKI with examples of diseases
pre-renal: due to inadequate blood supply to kidneys
ex.: hypovolemia, severe dehydration, shock, heart failure
intra-renal: disease of kidneys
ex.: glomerulonephritis, acute tubular necrosis
post-renal: obstruction of outflow of urine causing increased pressure and reduced function
risk factors to AKI
Hypotension
volume depletion (DEHYDRATION)
CKD
heart failure
diabetes
cirrhosis
nephrotoxic meds (NSAIDs, ACEi)
cancer
trauma
key presentations of AKI
Reduced urine output, high creatinine, hyperkalaemia (arrhythmias, muscle weakness), uraemia (pericarditis, nausea, vomiting, encephalopathy), fluid overload (pulmonary and peripheral oedema, hypovolemic shock, orthopnoea), hypotension, sepsis/acute illness, UTIs
what is uraemia
high urea in blood
what is orthopnea
Orthopnea is a medical term that describes difficulty breathing while lying flat. Individuals with orthopnea typically find relief by sitting up or propping themselves up with pillows. It is a symptom often associated with heart failure and other conditions affecting the respiratory and cardiovascular systems.
investigations for AKI gold standard
metabolic panel + urine output monitoring + urinalysis
serial U&Es daily (twice a day if needed)
for fast results you can also do a urine dipstick instead of a urinalysis but it is not gold standard
what is the management of AKI?
Treat underlying cause (hypotension, stones, infection).
Stop nephrotoxic drugs (NSAIDs, ACEi).
Treat complications (electrolyte imbalances).
Severe – haemodialysis
what test could provide fast information about the urine contents
urine dipstick
how do you test whether an AKI is prerenal or intra-renal and provide the parameters
urea: creatinine ratio - it provides info about whether the kidney disease is pre-renal or intra-renal.
pre-renal: ratio is more than 100:1 because decreased blood flow leads to increased reabsorption of urea in the renal tubules.
intra-renal: ratio is less than 40:1 (In conditions where there is damage to the renal tubules the reabsorption of urea may be impaired, leading to a proportionally smaller increase in BUN compared to creatinine.)
what is CKD
Chronic reduction in kidney function for more than 3 months which is permanent and progressive.
causes of CKD
Diabetes
hypertension
glomerulonephritis
polycystic kidney disease
nephrotoxic drugs (NSAIDs, ACEi)
persistent pyelonephritis
obstruction
what is pyelonephritis
kidney infection
how long does the kidney dysfunction have to be for to be classed as CKD
3 months
pathophysiology of CKD
Many nephrons are damaged causing decreased GFR which increases burden on remaining nephrons. Compensatory RAAS to increase GFR but trans-glomerular pressure is shearing, and a loss of basement membrane permeability causes protein/haematuria.