Kidney 4 Flashcards
Loop diuretics include
furosemide
bumetanide
ethacrynic acid
lasix dosing is
20-200 mg
Bumetanide dosing is
0.5-2 mg
Ethacyrnic acid dosing is
25-100 mg
Clinical uses of loop diuretics includes
acute pulmonary edema
AKI
CHF
hypercalcemia
HTN
anion overdose
intracranial HTN (not as effective as mannitol)
mobilization of edema fluid
Complications of loop diureticcs include
hypokalemic, hypochloremic metabolic alkalosis
hypocalcemia
hypomagnesemia
hypovolemia
ototoxicity
hypokalemia
reduced lithium clearance
Thiazide diuretics include
hydrochlorothiazide
chlorthialidone
metolazone
indapamide
The hydrochlorothiazide dose is
12.5-50 mg
Clinical uses of thiazide diuretics include
essential HTn
mobilize edema fluid
CHF
osteoporosis
Complications of thiazide diuretics include
hyperglycemia
hypercalcemia
hyperuricemia
hypokalemic, hypochloremic metabolic alkalosis
hypovolemia
HLD
sexual dysfunction
Potassium-sparing diuretics include
spironolactone
amiloride
triamterene
Spironolactone exists in a subclass of potassium-sparing diuretics called
aldosterone antagonists
Clinical uses of potassium-sparing diuretics include
secondary hyperaldosteronism
to reduce K+ loss in a patient receiving a loop or thiazide diuretic
Complications of potassium-sparing diuretics include
hyperkalemia
metabolic acidosis
gynecomastia
libido changes
nephrolithiasis
Identify the BEST tests of tubular function. (select 2)
a. blood urea nitrogen
b. urine osmolality
c. fractional excretion of sodium
d. creatinine clearance
b. urine osmolality
c. fractional excretion of sodium
Renal function tests provide an assessment of either
glomerular function or tubular function
Test of glomerular function include
BUN
serum creatinine
creatinine clearance
Tests of tubular function (concentrating ability) include
fractional excretion of sodium
urine osmolality
urine sodium concentration
urine specific gravity
Normal BUn is
10-20 mg/dL
Normal serum creatinine is
0.7-1.5 mg/dL
Normal creatinine clearance is
110-150 mL/min
Normal fractional excretion of sodium is
1-3%
Normal urine osmolality is
65-1,400 mOsm/L
Normal urine sodium concentration is
130-260 mEq/day
Normal urine specific gravity is
1.003-1.030
The best indicator of GFR is
creatinine clearance
_______ is the primary metabolite of protein metabolism in the liver
Urea
A BUN of <8 mg/dL is indicative of
overhydration
decreased urea production- malnutrition, severe liver disease
A BUN of 20-40 mg/dL is indicative of
dehydration
decreased GFR
increased protein input- increased diet, GI bleed, hematoma breakdown
catabolism- trauma, sepsis
A BUN of >50 mg/dL is indicative of
a decreased GFR
________ is produced by skeletal muscle and __________ is a metabolic byproduct of ________ breakdown
creatine; creatinine, creatine breakdown
Normal BUN: Cr ratio is
10:1
A BUN: Cr ratio of __________ suggests prerenal azotemia
> 20:1
Working kidneys_________ sodium, while failing kidneys _______ sodium
conserve; waste
If the fractional excretion of sodium is <1%, this suggests
prerenal azotemia
(more sodium is conserved relative to the amount of creatine cleared)
If the fractional excretion of sodium is >3%, this suggests
impaired tubular function (more sodium is excreted relative to the amount of creatinine cleared
A large amount of protein in the urine indicates
glomerular injury (>750 mg/day or +3 by urinalysis)
_________ is a better test of tubular function than specific gravity
Urine osmolality
What are the diagnostic test values for prerenal oliguria?
Fractional excretion of Na+ <1
Urinary Na+ <20
Urine osmolality >500
BUN: creatinine ratio >20:1
Sediment: normal, possible hyaline casts
What are the diagnostic test values for acute tubular necrosis?
fractional excretion of Na+: >3
urinary Na+: >20
urine osmolality <400
BUN:Creat ration: 10-20:1
sediment: granular casts, tubular epithelial cells
Anesthetic considerations for AKI include (Select 2:)
a. prerenal azotemia can cause acute tubular necrosis
b. hydroxyethyl starches are associated with an increased risk of renal morbidity
c. renal dose dopamine prevents AKI
d. diuretics should be used to convert oliguric to nonoliguric AKI
a. prerenal azotemia can cause acute tubular necrosis
b. hydroxyethyl starches are associated with an increased risk of renal morbidity
The most significant source of perioperative morbidity and mortality is
acute kidney injury
The most common cause of perioperative kidney injury is
ischemia-reperfusion injury
Patients at greatest risk for AKI include
those with pre-existing kidney disease
CHF
advanced age
sepsis
The problem with using urine output as a surrogate of renal perfusion is that oliguria is often the result of
the physiologic response to perioperative stress (increased ADH release during surgey)
We can classify AKI on the basis of
prerenal
intrinsic
or post renal injury
Prerenal injury is indicative of
hypoperfusion
Intrinsic injury is indicative of
parenchymal
Postrenal injury is indicative of
obstruction
