Changes In Flow

Question 1

In a unilateral obstruction, what is going on during the 3 phases?

Answer 1

1. Increase luminal pressure, which causes a reflexive increase in glomerular cap pressure to maintain GFR.
2. RAAS causes a decrease in blood flow due to constriction of afferent arteriole
3. Further drop in blood flow below baseline.

Question 2

After 24 hours, how far can GFR drop?

Answer 2

By 50%

Question 3

What tubular dysfunction do we see in unilateral and bilateral obstruction?

Answer 3

Inability to reabsorb sodium in unilateral. Volume expansion in bilateral.

Question 4

Triad of obstruction that the patient will present with when they have a urinary obstruction?

Answer 4

Azotemia, hyperkalemia, and metabolic acidosis

Question 5

What do we need to always remember with a man that has enlarged prostate?

Answer 5

Potential hydronephrosis

Question 6

What is the viscous cycle when the bladder isn’t emptying for whatever reason?

Answer 6

Bladder doesn’t empty so it stretches the bladder wall and ruins the integrity of the muscles leading to ineffective contraction of the bladder each subsequent time.

Question 7

How much urine needs to be left in the bladder to say it is incomplete emptying?

Answer 7

100 mls

Question 8

What is going on during post-obstructive diuresis?

Answer 8

During the obstructive down regulation of sodium transported occurs, so when the obstruction is fixed, the person can piss out a lot of urine. Support them until the kidney responds to normal.