Acute Kidney Injury Flashcards
True or false: You can feel pain in your kidney
False- Only in the ureters
How many nephrons can we lose before we start to see kidney decline?
1 million out of 2 million
How much glomerular filtrate enters?
100-120ml/min
What size of particles are able to bypass glomerulus filter?
under 70 kDa
What does the proximal tubule do?
substantial resorb and secrete
resorb 60-70% of Na most of K, Glucose
How ,much filtrate enters loop of Henle?
30ml/min
What does the descending part of loop resorb?
Water
What does the ascending loop resorb?
Na
What amount of filtrate enters distal?
5-10 ml/min
What does vasopressin do?
antidiuretic= resorb water NO na
What does aldosterone do?
Na resorb and K excrete
How much filtrate leaves the kidney?
1-2 ml/min
What are NCC channels and what drugs effect them?
These are thiazide sensitive channels NaCl cotransporter
What is ENaC?
This is amiloride sensitive channels, moves Na
What are the normal levels of Creatinine?
0.9-1.3
Why is creatinine a good marker for kidney function?
lots produced by muscles easily filtered in a normally functioning kidney. if rising levels this means that GFR is reduced
What is the Cockroft-Gault formula? (CrCl)
CrCl= (140-age)(IBW)/(0.814 x Scr(microM). x 0.85 if female
How to estimate IBW?
5 foot tall man= 50kg women= 45kg
add 2.3 kg for every inch
What is the MDRD equation?
GFR= 175 x Scr^-1.154 x age^-0.203 x 0.742(if female) x (1.212 if black)
Are drugs more likely to be filtered if they are mostly protein bound?
NO
Give me the stages of CKD and their corresponding GFR
1= >90
2= 89-60
3a=59-45
3b= 45-30
4= 30-15
5=<15 OR dialysis
What are the stages of Albuminuria?
1= <30
2=30-300
3=>300
WHat is the size of albumin?
67kDa
Spec gravity normal values
1.005-1.029
When can you diagnose AKI?
if Sir rises by 25microM in 2 days or decrease of urine to less than 0.5 ml/kg/hr for 6 hrs
Symptoms of AKI
low urine output
fatigue
swellling
confusion
What are the causes of AKI
pre renal azotemia
Intrinsic renal parenchyma disease
post renal obstruction
What is pre renal azotemia
increase of blood urea due to reduced glomerular pressure
NO signs of damage to tubules
reversible before damage
due to low BP, low CO, medications ie) NSAIDS
What conditions can cause pre renal azotemia
atherosclerosis, hypovolemia, NSAIDS
How does NSAIDS cause AKI
1-reduce flow to kidney
2-direct injury= nephritis
How does Glomerulus usually get injured?
HTN, diabetes, immune due to auto or antigens getting stuck there,
T/F Glomerular injury is reversible
False
How do tubular systems get damaged
Necrosis due to ROS from toxins, direct toxicity, rhabdomyolysis
How does Cisplatin cause damage to tubules?
accumulates in proximal tubule, direct toxicity, more hydration lowers toxicity
How does rhabdomyolysis effect tubules?
myoglobin from muscle injury can precipitate and halt flow
What symptom of rhabdomyolysis is indicative of kidney issues?
DARK urine
What drug can cause rhabdomyolysis
STATINS
What drug can cause rhabdomyolysis
STATINS
What causes interstitial nephritis?
Inflammation of interstitial space
usually caused by sensitivity to drugs like penicillins, NSAIDS
Why does ischema affect the kidneys so much?
because the kidneys use up a lot of oxygen and blood
hypoxic region of kidney very sensitive to O2 levels
What part of the kidney operates at hypoxic levels
Medulla
What conditions increase kidney damage?
atherosclerosis, ischemia,
T/F Necrosis of tubules is reversible
True
What is the only way to confirm intra renal damage?
biopsy
True or false Kidney stones are directly related to calcium intake
False
What increases your risk of kidney stones?
dehydration, protein intake, high salt intake(causes Ca excretion)
What does RIFLE stand for
R=Risk
I=injury
F= failure to function
L=loss of function
E=ESRD
What are the GFR and UO Criteria for R of RIFLE
increase of Scr 1.5 x baseline, GFR decrease by 25% or <0.5 urine /kg/h for 6 hrs
What are the GFR and UO Criteria for I of RIFLE
increase of Scr 2 x baseline, GFR decrease by 50% or <0.5 urine /kg/h for 12 hrs
What are the GFR and UO Criteria for F of RIFLE
increase of Scr 3 x baseline, GFR decrease by 75% or <0.3 urine /kg/h for 24 hrs or no pee for 12 hrs
What are the GFR and UO Criteria for L of RIFLE
no function for 4 weeks
What are the GFR and UO Criteria for E of RIFLE
ESRD
what are the pros and cons of RIFLE
Pros- good accuracy
cons= baseline not known, MDRD only for CKD, using only Scr decreases accuracy
What is the criteria to be in stage 1 of AKIN?
increase of Scr 1.5-2 x baseline or >0.3 mg/dl in 2 days UO< o.5ml/kg/h for 6 hrs
What is the criteria to be in stage 2 of AKIN?
Increase of Scr 2-3 x baseline
UO<0.5ml/kg/h for 12 hrs
What is the criteria to be in stage 3 of AKIN?
Increase of Scr >3 x baseline or >4mg/dl DIALYSIS
or No pee in 12 hrs or <0.3ml/kg for 24 hrs
Complications of AKI
Pulmonary edema, anemia, weakness, hyperkalemia, acidosis
Complications of AKI
Pulmonary edema, anemia, weakness, hyperkalemia, acidosis
How does pulmonary edema happen
Na K ATPase, ENaC and aquaporin down regulated= retain fluid and inflammation
How does hyperkalemia happen in AKI
Distal tubules damaged= can’t excrete K
How does metabolic acidosis happen in AKI
loss of bicarbonate= causes nausea and vomitting
How can you prevent AKI
only reduce risk by living healthy, managing conditions, and being careful with meds
How to generally treat AKI
treat underlying cause, balance fluids, electrolytes, control K and Ca, dialysis
What are the kidney dialysis options?
Hemodialysis- blood is removed filtered then returned
peritoneal dialysis-put into cavity the solution absorbs toxins then remove
What are the cons of Hemodialysis
Need blood thinners, permanent graft need surgery, or
T or f Diuretics help with AKI
False
What are the thiazide diuretics?
indapamide, chlorothiazide, hydrochlorothiazide
What are the loop diuretics
furosemide, torsemide, numetanide
Potassium sparing diuretics
amiloride, ARA, spironolactone
Osmotic diuretics
mannitol, glycerine, urea
When do we want to use thiazide diuretics
HTN
What are the side effects of thiazide
hypovolemia, hyperglycaemia
Where do the loop diuretics act
ascending limb= block Na resorb
Where do the loop diuretics act
ascending limb= block Na resorb
Side effects of loop diuretics
electrolyte loss, hypotension, cramps, hyperglycaemia
Side effects of loop diuretics
electrolyte loss, hypotension, cramps, hyperglycaemia
Do K sparing diuretics lower blood pressure
NO
Do K sparing diuretics lower blood pressure
NO
Adverse effects of K sparing diuretics
hyperkalemia= arrythmias
cramp, ab pain
Where do osmotic diuretics act
proximal tubule,
Where do osmotic diuretics act
proximal tubule,
adverse effects of osmotic diuretics
electrolyte loss, headache, dizzy
What cancers cause AKI
Kidney, liver, bladder, leukaemia
What anticancer agents cause AKI
Cisplatin, gemcitabine, mabs, PD-1 and PD-l1 inhibitors
What anticancer agents cause AKI
Cisplatin, gemcitabine, mabs, PD-1 and PD-l1 inhibitors
How to treat AKI if they have cancer too
very aggressively as prognosis is very poor
