Polyuria/Polydipsia
With lots of _____ and high concentrations of _____ and _____, lots of water will move out of the renal tubules and a large volume of concentrated urine will be made
aquapoins; Na; BUN
ADH in the renal medulla causes _____ to be inserted into the distal tubule and collecting ducts
aquaporins
_____ are pores through which water moves, movement of water through these pores is a passive process
aquaporins
MWDT absolute endpoints: 1. _____ (ABSOLUTE contraindication) 2. plasma osmolality >_____ mOsm/kg - ADH secretion should be maximal when this is reached 3. USG >_____ in dogs and >_____ in cats 4. loss of >_____% body weight
azotemia; 320; 1.030; 1.035; 5
With Lepto you expect them to become _____ or have elevated _____ enzymes
azotemic; liver
If they are eating a lot of _____ food then there can be a lot of water intake through what they are eating
canned
Primary polydipsia is NOT very _____
common
As urine goes down the descending LOH it is highly _____
concentrated
If there are maximal ADH concentrations present, urine will be excreted as very _____
concentrated
The more _____ the renal medulla, the more water will be pulled out of the renal tubules and the more _____ the urine will be
concentrated; concentrated
Causes of ADH deficiency (central DI): 1. _____ 2. _____
congenital; acquired
At the beginning and every 2 hours of the MWDT you should: 1. measure _____ - if this is high you CANNOT do the test, you ONLY do this in the BEGINNING 2. check _____ - if creatinine is normal 3. serum _____ 4. check _____ - if they become dehydrated you are done 5. _____ bladder 6. _____
creatinine; USG; osmolality; hydration; empty; weigh
ALWAYS measure _____ the morning of the MWDT, if they are _____ do NOT do the test!!!
creatinine; azotemic
Causes of osmotic diuresis: 1. _____ - see glucose in the distal tubules 2. primary renal _____ - kidney problem where the renal tubules cannot reabsorb the glucose 3. _____ renal failure 4. _____ diuresis - relieved urethral obstruction
diabetes mellitus; glycosuria; chronic; post-obstructive
As urine comes back up the ascending LOH it is very _____
dilute
If there is no ADH present then urine is not concentrated as it moves through the distal tubule and collecting duct and the urine that is excreted at the end will be very _____ and will have a USG of _____
dilute; 1.000
NDI interpretation: 1. initial: _____ (USG <_____) 2. endpoint: _____ respond (USG <_____) 3. post-ADH: _____ respond (USG <_____)
dilute; 1.006; can't; 1.006; can't; 1.006
Complete CDI interpretation: 1. initial: _____ (USG <_____) 2. endpoint: no _____ (USG <_____) 3. post-ADH: _____ (USG >_____)
dilute; 1.006; response; 1.006; respond; 1.018
Partial CDI interpretation: 1. initial: _____ (USG <_____) 2. endpoint: some _____ (USG _____-_____) 3. post-ADH: more _____ (_____-_____% increase in USG)
dilute; 1.006; response; 1.008-1.020; response; 10-50
If there is _____ urine the urine sediment exams are NOT reliable for dx of UTI, therefore a urine _____ needs to be done
dilute; culture
Types of primary polyuria: 1. osmotic _____ 2. _____ deficiency (central DI) 3. lack of _____ response
diuresis; ADH; ADH
If they are eating dry food, most of their water intake will be through _____
drinking
The basic problem with primary polyuria is that they are _____ too much
drinking
Get a good hx: 1. _____ - include topical glucocorticoids 2. _____ change 3. other problems 4. _____uria vs _____uria vs _____
drugs; diet poly; dys; incontinence
_____ is another factor of normal water metabolism
eating
Dx PU/PD: 1. establish that PU/PD _____ 2. get a good _____ 3. thorough _____ 4. minimum _____ 5. test for specific _____
exists; hx; PE; data base; diseases
DDAVP response test = _____ ADH
exogenous
_____ fluid osmolality is the main thing that controls ADH, this is a very sensitive system
extracellular
Other factors of water output: 1. _____ 2. _____ tract - esp. in hot weather due to panting
feces; respiratory
Drugs that cause PU/PD: 1. _____ - PU/PD is the #1 side effect of these drugs 2. _____ 3. _____ - increase H2O output for a living, so the dog is going to drink more
glucocorticoids; phenobarbital; diuretics
Things that interfere with secondary messengers thus causing secondary NDI: 1. _____Ca 2. _____K 3. _____- due to toxin that E. coli releases 4. _____ - interferes with the function of tubules and can cause PU/PD 5. _____ - can cause PU/PD in the absence of any other clinical signs
hyper; hypo; pyometra; pyelomephritis; Lepto
Conditions that cause low Na/BUN and thus secondary NDI: 1. _____ - classic example of low Na 2. _____ protein diet - leads to low BUN and thus increased water consumption 3. _____ failure - leads to low BUN 4. renal medullary _____
hypoadrenocorticism; low; hepatic; washout
Ways to est. that PU/PD exists: 1. measure water _____ - have to be strict about the water sources 2. _____ (collect at home) - this should be a first morning urine sample
intake; USG
Normal water metabolism is an _____ system
integrated
When urine is first made it enters the proximal tubule and is _____ (same concentration as _____, USG of _____)
isosthenuric; serum; 1.010
Thirst kicks in _____ than ADH secretion, but is controlled similarly
later
Medullary washout occurs due to _____ Na/BUN
low
_____ protein diets can decrease BUN and thus increase drinking behavior
low
Secondary nephrogenic DI = ADH receptor _____
malfunction
Lack of ADH response =
nephrogenic DI
In the distal tubules and collecting ducts water is pulled out of the tubules by an osmotic force
osmotic diuresis
*See Annabelle's other results. What is your interpretation of the MWDT?*
partial central DI
When you have a more dilute _____ there is not much secretion of ADH
plasma
Stimulation of ADH secretion: 1. _____ osmolality #1 2. _____% decrease in blood volume
plasma; 10
Unknown mechanisms that cause secondary NDI: 1. _____ 2. _____ 3. _____
polycythemia; hyperadrenocorticism; hyperthyroidism
ADH comes from the _____
posterior pituitary
The problem is that the patient cannot concentrate their urine, so they are urinating a lot and are drinking to prevent dehydration
primary polyuria
DDAVP response test is only used when 3 differentials remain: 1. _____ 2. _____ 3. _____
psychogenic polydipsia; CDI; primary NDI
Types of primary polydipsia: 1. _____ - behavioral issue, anxiety issue 2. _____ failure - as a manifestation of hepatic encephalopathy
psychogenic polydipsia; hepatic
ADH will make a dog with _____ concentrate its urine, so it can be difficult to differentiate between _____ and _____
psychogenic polydipsia; partial CDI; psychogenic polydipsia
Modified water deprivation tests are ONLY designed to differentiate between: 1. _____ polydipsia 2. _____ DI 3. _____ DI
psychogenic; central; primary nephrogenic
Primary nephrogenic DI = lack of ADH _____
receptors
With NDI they do NOT have ADH _____, so urine will remain very _____
receptors; dilute
Most common causes of primary polydipsia in cats: 1. _____ failure 2. _____ 3. _____
renal; diabetes mellitus; hyperthyroidism
Most common causes of primary polydipsia in dogs: 1. _____ failure 2. _____ 3. _____
renal; hyperadrenocorticism; diabetes mellitus
Something is going on in the body that is preventing the kidneys from responding to ADH
secondary nephrogenic DI
_____ NDI should NOT even be a consideration b/c you have to rule out _____ first before you do a MWDT!
secondary; secondary
Normal water metabolism is a precise regulation of: 1. water intake, mainly by _____ 2. water output, mainly by _____
thirst; vasopressin
No _____ limit exists for the MWDT, so an emergency or 24 hr clinical may be utilized
time
_____ tract infections can cause PU/PD
urinary
*What test do you want to do next if CBC/proflie are unremarkable and you have done a UA?* See "Annabelle" Buff case!!!
urine culture
You would put Addison's disease higher if the dog is _____
vomiting
Causes of secondary nephrogenic DI: 1. medullary _____ 2. interference with ADH _____ messenger system 3. _____
washout; secondary; unknown
PU/PD can be defined clinically by measuring how much _____ there is
water intake
What is the main function of anti-diuretic hormone (ADH) aka vasopressin?
water retention
ADH (vasopressin) increases _____ as well
BP
Minimum data base for a PU/PD patient: 1. _____ 2. profile with _____ - a measure of kidney function 3. _____ 4. urine _____
CBC; SDMA; UA; culture
Interpretation of DDAVP response test: 1. dramatic (>50%) decreased water intake and/or increased urine concentration: strong evidence of _____ 2. moderate response: _____ 3. _____ - will respond
CDI; partial CDI; psychogenic polydipsia
Primary polydipsia interpreation: 1. initial: USG _____-_____ 2. endpoint: _____ (USG >_____) 3. post-ADH: N/A
1.002-1.020; concentrated; 1.030
Increased thirst: 1. dogs: >_____ ml/kg/day 2. cats: > _____ ml/kg/day
100; 45
*If it is a dog and the culture is negative, what is your top differential?* 1. DM 2. hyperadrenocorticism 3. Addison's disease 4. hyperthyroidism
2 - want to do an ACTH stim test
Protocol for DDAVP response test: 1. measure water intake for _____-_____ days 2. tx with DDAVP for _____-_____ days 3. monitor water intake and urine output on days _____-_____ to see if they are responding to exogenous ADH hormone
2-3; 5-7; 5-7
Steps of the modified water deprivation test: 1. restrict water slowly over _____-_____ days to get them down to _____ ml/kg/day 2. at start take _____ water away 3. make sure an _____ endpoint is reached 4. if not concentrated at endpoint, give _____ and see what happens
2-4; 100; all; absolute; ADH
If you have to send them home while doing a MWDT at the end of the day you should: 1. _____ ml/kg/water/hr unobserved 2. next morning - _____, take away _____, _____ test
2.75; weigh; water; continue
Patients become PU/PD when they lose _____ of their nephrons
2/3
Factors of plasma osmolality that stimulate ADH secretion: 1. _____% increase in ECF osmolality 2. max: _____ mOsm/kg
2; 320
Patients become azotemic when they lose _____ of their nephrons
3/4
Once you hit a plasma osmolality of _____ you have maximal ADH secretion
320
Things you have to have to respond to ADH: 1. >_____% nephrons 2. _____ renal medulla 3. ADH _____ on the tubules to be able to respond
33; hypertonic; receptors
*Which of the following is NOT needed to concentrate urine?* 1. adequate ADH 2. adequate ADH response 3. adequate Na 4. adequate BUN 5. adequate Ca
5
Tests for specific diseases: 1. _____ (dogs) - Cushing's can cause only PU/PD and nothing else 2. _____ (cats) - ALWAYS
ACTH stim; T4
With complete CDI at the endpoint there will be no response b/c they have no _____ so they cannot concentrate their urine
ADH
With primary nephrogenic DI they have lack of ADH receptors, therefore they cannot respond to _____
ADH
*What is the main hormone that helps concentrate urine?*
ADH (vasopressin)
Things needed to concentrate urine: 1. enough _____ 2. response to _____
ADH; ADH
Any time you have a huge abscess filled with _____ you can have PU/PD
E. coli
A modified water deprivation test should be done _____!!
LAST
DDAVP response test is an option to _____
MWDT
*See Annabelle's MWDT results. Has an endpoint been reached?*
NO - she has not concentrated her urine, plasma osmolality is still less than 320, and she has not lose 5% of her body weight
*A 30 kg dog eats a mix of dry and canned food. he drinks 2400 ml water/day. Is this PU/PD?*
NOT sure b/c they are eating a mix of dry and canned food and you cannot tell how much water they are getting from their diet
If you do not have adequate concentrations of _____ and _____ you can see medullary washout
Na; BUN
_____ and _____ are the main things that must be present in the medulla
Na; BUN
_____ and _____ in the renal medulla are important in concentrating ability
Na; BUN
Diabetes insipidus is a _____ disease
RARE
_____ will increase BEFORE creatinine
SDMA