Medical Disorders of the GI tract Flashcards

1
Q

What are some examples of important historical questions to ask in a colic case?

A
  1. What is the horse doing and how long have they been doing it?
  2. How severe is the pain?
  3. Have they colicked before? Have they had colic surgery before?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are some parameters that indicate that immediate evaluation and treatment is needed?

A

Recent colic surgery, horse has just foaled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the steps you should take to evaluate a horse during a colic workup?

A
  1. Observe severity of horses signs, assess the environment
  2. Physical exam (assess scrotum, edema presence), more history questions
  3. Sedation considered prior to rectal exam after you get a heart rate (+ buscupan, twitch if needed, can also do lidocaine infusion into the rectum)
  4. Pass NG tube to see if there is any reflux (normal is <2), have mineral oil and epsom salts prepared
  5. Collect blood for PCV, TP and lactate
  6. Abdominal ultrasound +/- abdominocentesis (to measure lactate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does buscopan result in?

A

Decreased to absent gut motility, increased HR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

If you cant feel small intestine on rectal palpation, what should you expect when passing a tube?

A

There is unlikely to be a lot of reflux, more likely impaction?- consider adding mineral oil/epsom salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the biggest decision you need to make when working up a colic case?

A

Whether you can treat on the farm or you need to refer or you need to euthanize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do clinicians feel like are the main clinical findings that indicate a horse should be referred?

A
  1. Unrelenting pain only briefly controlled with sedation
  2. Persistently elevated HR (>60 bpm), slow CRT
  3. A large amount of net reflux (>6 to 8 L)
  4. Abnormal palpation findings
  5. Client willingness to refer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the main findings that indicate a horse needs to be euthanized in a colic case?

A
  1. Evidence of advanced endotoxic shock, possible rupture
    - purple mucous membranes, cold extremities, extreme depression, prolonged CRT
    - abdominocentesis: if feed material is visible in the fluid, obtain samples from several sites to rule out possible enterocentesis and confirm rupture
  2. Advanced disease and client cant/wont refer to a hospital
  3. Advanced disease and a horse is a long distance from the practice making rechecks or return for euthanasia difficult
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe how you can estimate dehydration in a horse

A

4-6%: skin tent of 2-3 seconds, mucous membrane moisture is fair, CRT 1-2 seconds, PCV 40-50, TP 6.5-7.5
7-9%: skin tent of 3-5 s, sticky mucous membranes, CRT 2-4 s, PCV 50-65%, TP 7.5-8.5
>9%: skin tent >5, dry mucous membranes, CRT >4, PCV >65, TP >8.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 2 main goals of fluid therapy?

A
  1. Volume expand (rehydrate) the horse to reestablish perfusion
  2. Keep up with maintenance needs and ongoing losses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

If the gut is working, what is the best way to deliver fluids in the field?

A

Orally
-through NG tube if possible (can stay in place a couple of days). Small bore tube recommended (can eat with this in place), and tape it to halter, then cover end.
-if the horse needs fluids fast, an IV bolus should be considered
-show client how to check for reflux and how to add fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the maximum stomach volume of a 500 kg horse stomach?

A

16 L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a comfortable delivery volume of oral fluids for a 500 kg horse?

A

10 L/30 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

If continuously administering oral fluids, what should you add to them?

A

Lite salt (KCL and NaCl)
-add 75 g of each to 10 L of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

To rehydrate a patient quickly how much of the total deficit should you try to deliver in the first hour?

A

40-50%
-deliver the remaining deficit in the next 4-6 hours
-dont want to give more than 10 L at a time (10 L/30 min)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the shock fluid rate for horses?

A

20 L/hr
-give 2 boluses 30 min apart (check for reflux in between)
-monitor blood protein after the first 20 L and adjust rate accordingly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the IV fluid administration that you can do in the field?

A

-usually a 1 time administration of 5-20 L for acute rehydration and perfusion
-shock rate of 45 mL/hr=22.5 L/hr
-perform in order to reestablish perfusion to the gut and improve motility (bridge to oral fluids or tube feeding in neonates)
-general trt for shock and/or exhaustion
-restore adequate hydration/perfusion to get to a referral hospital
-one time need, such as in acute hemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the advantages and disadvantages to oral fluids?

A

Advantages: can be done on farm, cheap, relatively easy if client knows how to manage this

Disadvantages: risk of tube pull out and/or aspiration, more management on vets part

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How often and what parameters should you monitor in colic cases that you are managing on the farm?

A

-Can teach client to check basic physical exam findings (body weight, USG, PCV/TP, blood electrolytes, TPR)
-with rapid delivery of fluids, monitor these every few hours
-in unstable patients, monitor every 12 hours, then every 24-48 once stabilized

20
Q

What changes can you expect if a horse is overhydrated? Underhydrated?

A
  • excessive urination
  • edema (abdomen, limbs, pulmonary-elevated RR)

If underhydrated, may see tacky mucous membranes, tucked up abdomen, lack of urination

21
Q

If the horse develops edema but still has mildly concentrated urine, what might be going on and how would you treat the problem?

A

Low total protein
-add colloid therapy

22
Q

T/F: if a horse is refluxing, you should not add anything orally

A

True

23
Q

Why is dioctyl sodium sulfosuccinate no longer used in colic cases?

A

It is associated with causing severe colitis

24
Q

If you are considering referral for a horse that is not doing well clinically (aka shocky), what is a fluid type you should consider?

A

Hypertonic saline (1-2 L/500 Kg horse)
-allows for rapid blood volume expansion and restoration of perfusion
-takes fluid from intercellular and interstitial spaces to restore blood volume
-improves cardiovascular status for about 2 hours
-need to follow up with IV fluid therapy to replace fluids from the intercellular and interstitial spaces

25
Q

What are the main rules when it comes to fluid therapy?

A
  1. Provide fluids with electrolytes added
  2. Check for reflux in between each fluid delivery
  3. Do not give oral fluid if there is more than 2L of reflux, if the horse coughs when fluid delivery starts, the tube has come out fairly far or the horse is painful
    4.Monitor PE, urinations, defecations, PCV, TP, USG at least twice a day and adjust fluid volume based on these findings
  4. Place marks on tube for client: one where tube should be in nostril and one where the tube has come out too far for them to use it
26
Q

What does oncotic pressure refer to?

A

The proteins that are circulating in the blood
- includes albumin, globulins, and fibrinogen
- what keeps the water in the vascular bed is the charges on these proteins

27
Q

Of the 3 proteins that contribute to oncotic pressure, which is the most important?

A

Albumin
- it is half the weight of a globulin molecule but contains 2X the molecules
- it can leak quickly and cause quick drop in oncotic pressure
- ability to evert force is much more than globulins

28
Q

What contributes to osmotic pressure?

A

Sodium presence in the capillary bed helps to keep fluid there
- when concentration in the capillary beds or outside of the capillary beds increases, water will follow the sodium to equalize the concentration

29
Q

What is the reflection coefficient?

A

How readily a molecule passes through a membrane
- an RC of zero indicates minimal membrane selectivity (example- the spleen and liver)
- RC of one indicates maximal membrane selectivity (molecule does not go through the membrane- such as in the brain)

*RC value of capillary endothelium is tissue specific

30
Q

What keeps fluid in the blood?

A

The combined effects of oncotic and osmotic pressure

31
Q

What are the categories of disease processes that allow fluid to move from the capillary beds into the tissues, promoting edema?

A

Protein decreasing diseases: increased consumption, increased losses, decreased production
- protein losing enteropathies, starvation, etc

Loss of vascular wall integrity
- vasculitis

Hyponatremia

32
Q

What diseases cause a decrease in oncotic pressure (low blood protein)?

A

-gut inflammation causing protein losing enteropathy
-protein losing nephropathy
-hepatopathy
-peritoneal, pleural effusion
-lack of substrate: starvation, malabsorption

33
Q

What diseases cause a decreased osmotic pressure (sodium loss)?

A

-gut inflammation interfering with sodium absorption and retention
-water overload
-pleural or peritoneal fluid presence (sodium sequestration)
-ruptured bladder (most common in neonatal foals)
-adrenal dysfunction (rare)

34
Q

What diseases cause vasculitis?

A

Endotoxemia (can lead to laminitis), infectious causes, immune mediated disease
-vasculitis can be associated with thrombosis

35
Q

What is petechia a clinical manifestation of?

A

Vaculitis
- these are microthrombi

More commonly see edema as a result of vasculitis

36
Q

How can you treat for hypoproteinemia and aid in fluid replacement?

A

Oncotic replacement with plasma or hetastarch

37
Q

What are the main indications for plasma transfusions?

A

-TP <4 g/dL, especially if drop is rapid
-edema in limbs, prepuce, pectoral or ventral region, muzzle
-harsh, wet lung sounds, increased respiratory rate
-thickened bowel (seen on abdominal ultrasound)

38
Q

How do you calculate the replacement volume of plasma?

A

(desired TP-measured TP) (.05 X BW)/donor plasma protein concentration

39
Q

What is the normal desired TP in a horse?

A

6 g/dL

40
Q

What is the shortcut for plasma protein replacement?

A

When treating a 400 to 500 kg horse, plasma protein will increase by 1 g/dL for every 4 L of administered plasma that has 6 g/dL of protein

41
Q

What are some rules for plasma protein replacement in foals?

A

When treating a 40 to 50 kg foal for FPT:
- normal foal with low IgG should get 1 L hyperimmune plasma
- sick foal with low IgG should get 2-3 L of hyperimmune plasma
- administer using the same methods as adults
- recheck the IgG 12-24 hours after administration

*use commercial plasma- should have guaranteed amount of protein, and should not react against baby’s red cells

42
Q

How do you deliver plasma?

A

Start slowly: give 0.5mL/kg over 30 min
- monitor HR, RR and temp every 5 min for first 30 min
- observe continuously during entire transfusion period

If no reactions, then gradually can increase rate in 5-10 min intervals to 40 mL/kg/hr
*if infusing multiple liters, use plasma from the same donor
*use fluid set with filters in the drip set to avoid introduction of fibrin
*always try to get plasma from the same donor, or if using different donors start process over again

43
Q

How should you thaw plasma?

A

In warm water, never in the microwave

44
Q

Describe the features of hetastarch

A

-starch from amylopectin
-dose is 10 mL/kg
-low toxicity
-eliminated over several days to a week
-falsely lowers plasma protein
-may cause coagulopathies, renal disease
-slightly less expensive than plasma

*does not affect plasma protein on refractometer

45
Q

What is the best route for introducing electrolytes to animals?

A

oral- should be calculated to provide a starting point
-monitoring is essential because the response in sick animals is variable

46
Q

How can you treat vasculitis?

A

-identify and treat the cause
-can use NSAIDS like flunixin or bute to reduce inflammation
-pentoxifylline reduces blood viscosity, improves RBC flexibility and increases microcirculation, but effect is variable in horses
-steroids? use caution due to the risk of laminitis
-can try low molecular weight heparin