Diuretic (Lasix) Renal Study

Question 1

indications

Answer 1

• distinguish between dilation or obstruction (hydronephrosis)
• success of sx to relieve obstruction

Question 2

contraindications for Lasix

Answer 2

• anuria
• dehydration; off diuretics
• iv contrast
• discontinuation of Diclofenac (NSAID) is needed
• allergy to Lasix
• severe hypotension

Question 3

mechanism of action for Lasix

Answer 3

inhibits reabsorption of Na+ in loop of Henle = increase urine production

Question 4

method of admin for Lasix

Answer 4

slow IV infusion over 1-2 mins

Question 5

Lasix dose

Answer 5

20-80 mg, typically 40 mg

Question 6

when is Lasix administered?

Answer 6

typically when there is a build-up of activity in renal pelvis. usually 15-20 mins

Question 7

when does peak diuretic response occur?

Answer 7

10-15 min post Lasix injection

Question 8

if there is an obstruction, what will we see?

Answer 8

the renogram will show that during excretion phase, there will be little decrease in the collecting system’s activity

Question 9

post Lasix admin
T1/2 = <10 mins

Answer 9

non-obstructed/hydronephrosis/functional obstruction

Question 10

post Lasix admin
T1/2 = 10-20 mins

Answer 10

indeterminate

Question 11

post Lasix admin
T1/2 = >20 mins

Answer 11

mechanical obstruction

Question 12

what can cause false positive for obstruction?

Answer 12

• dehydration
• RIGID renal pelvis, yet a very stretchy one as well…
• full bladder