Exam 1 Flashcards
What are the 3 basic responsibilities of a Vet?
- Make Diagnoses
- Treat abnormalities using evidence based medicine (when possible)
- Keep up-to date on advances
What is the diagnostic reasoning process
Arrival at a diagnosis by obtaining complex, convoluted, and confusing information on a patients and comparing it to what is expected to be normal “art of veterinary science”
What is the Problem-oriented approach? and why do we use it? ** learning objective**
Idea that medicine should be practiced with a set of rules in order to cope with the complex information obtained about a patient. Ensures each animals problems are diagnosed and managed logically and thoroughly. Foundation rests on (1) Systematic collection of info and (2) assembly of a database that is the same for each patient
What does the problem-orientated approach database include? (9 main points/steps)
** Learning objective**
- Signalment
- Owners complaint
- History
- Physical Exam
- Working Problem List
- Differential Diagnosis (DD) list - use “DAMNIT” to jog your memories
- Plan to rule -in/-out each DD
- Treatment Plan and Prognosis
- Therapeutic plan and monitor its efficacy via SOAP
Signalment
age, breed and sex first thing you should know or tell another clinician about a patient
Owners Complaint
What you should always address. Ensure owners interpretation is correct.
6 General Rules of Taking a History
** Learning Objective**
- Avoid confusion. Use simple english and ask one question at a time
- Cross-check statements for accuracy
- DO NOT use leading questions
- Establish a chronological timeline
- OPEN_ENDED QUESTIONS!!!
- Summarize understanding to owner to avoid miscomm6unications
What is the most common cause of disputes b/w owners and vets?
a. miscommunication
b. money
c. diagnosis
d. sports
miscommunication
What is a: Working Problem List
Identification and prioritization of a patients problems. Some problems can be “lumped” together if thought to be due to a common cause. Make less urgent problems “inactive” , rather than discarding them Focus on distinguishing CS ( ex. dark feces, pale mucous membranes) and avoid general CS (ex. anorexia, lethargy)
What does DAMNIT stand for?
**Learning objective**
D- developmental, degenerative
A- anatomical, autoimmune, allergies
M- metabolic
N- neoplastic, nutritional
I- idopathic, iatrogenic, inflammatory, infectious
T- toxicities, trauma
Textbooks also outline DDx’s
What should you consider when you devise a diagnostic plan?
Choose diagnostic test that:
- cause minimal pain/stress
- -safe
- -simple
- -can rule-in/-out multiple DDx simultaneously
- -can diagnose common diseases
- -cheap
Master Problem List
Summary of the patients problems and medical history. Includes updated list of DDx, plans and important test results until definitive diagnoses is made
What should be discussed with the owner in your treatment plan?
– best treatment and prognosis for each disease – probability the animal will recover with and without treatment – how much each treatment will cost
What should you use to monitor the efficacy and side-effects of therapies/treatment plans?
** learning objective**
progress notes in problem-oriented record system
the progress notes are written using the SOAP format
What does SOAP stand for?
** learning objective**
S- subjective- what the owner tells you
O- Objective- what you observe
A- Assessment- what you think is going on and if the treatment is working
P- Plan- what you intend to do
Why do we keep medical records?
** learning objective**
- legal requirement and important evidence should any disputes arise with a client
- To identify recurring problems and their most appropriate therapy
- Continuity of care in multi-vet practice
- Accurate costing an d financial management
- Research
Summarize the steps involved in diagnosing and treating a disease
–Signalment –Owners complaint and history –PE –Make problem list –determine a DDx list for each problem –Devise plan to Rule- in/-out each DDx for each problem –Revise DDx list as new information is generated –Make final diagnosis of each problem –Treat each problem –Monitor therapy –Keep accurate and thorough records
What is the general outline of how a physical exam is preformed? ** learning objective**
See notes… pretty basic stuff
Describe intracellular and extracellular spaces?
Intracellular space contains 2/3 of total body water (about 40% of body weight)- Cells are dehydrated first
Extracellular space has 1/3 of total body water; contains fluid that is not in the cells. Divided into 3 compartments
– Interstitial: ¾ of extracellular fluid
– Intravascular: mostly plasma; within blood vessels
– Transcellular: specialized fluid/areas (CSF, bile, synovial fluid, GI fluid)
What are three main reasons to give fluids?
Maintenance: the required volume needed per day to keep the patient in balance, with no change in total body water.
Dehydration: Decreased fluid in intracellular or interstitial spaces (intravascular space too if shock ensues).
Shock: Decreased fluid in intravascular space
What routes can you give fluids?
IV and SQ
IV is most appropriate for dehydration and shock
What is the normal PCV for dogs? grey hounds?
Dogs: 35-60%
Greyhounds: 65-70%
What is the best choice fluid if you have a unknown diagnosis and/or no lab results?
Crystalloid replacement fluids
In an “ideal world” what should you base your fluid type on?
Results of RBC count & chemistry profile (electrolytes, glucose)
Difference between crystalloid & colloid fluids? Provide Examples of each.
** Learning Objective**
1. Crystalloids: Solutes (electrolytes & non-electrolytes) that can move freely around the fluid compartments. Divided into groups based on tonicity (ability to shift water across semipermeable membranes) =Hypotonic, hypertonic and isotonic.
2. Colloids: Larger molecular weight. Remain in intravascular space & keep fluid in intravascular space. Compare to crystalloids which end up in interstitial spaces.
Natural: plasma, whole blood
Synthetic: hetastarch, dextran, pentastarch, ‘oxyglobin’
What are the 3 categories of crystalloid fluids?
-
Hypotonic: Lower osmolality than intravascular fluid so draws fluid into cells.
- Ex. 0.45 % NaCl, 5 % dextrose in water
-
Hypertonic: Higher osmolality than blood cells and plasma. Will draw fluids from interstitial & intracellular spaces into intravascular space.
- Ex: 7.5 % NaCl solution, 5% dextrose in following: Normosol M, 0.45 % NaCl, 0.9% NaCl, LRS, Plasmalyte 56 .
-
Isotonic: Same osmolality as blood cells and plasma so fluids will neither exit or enter cells. Used for perfusion support & volume replacement.
- Ex: 0.9 % NaCl, Ringer’s solution, LRS, Normosol R, Plasmalyte A, 0.45 % saline with 2.5 % dextrose
What is the most common synthetic colloid fluid?
Hetastarch
Which type of crystalloid fluid is most common?
Isotonic crystalloids
LRS
Why would you use crystalloid fluids?
- correct dehydration
- expand vascular space in shock
- correct electrolyte/acid-base imbalances
Give examples of synthetic colloids. Which is most commonly used one?
Synthetic Colloids: hetastarch, dextran, pentastarch, ‘oxyglobin’
Hetastarch is most commonly used!
What could happen if you give a large amount of crystalloid?
** Learning Objective**
Peripheral edema
Since crystalloids are freely permeable to enters cell membranes. 2/3 enters interstitial space.
Most common if too much, too rapidly and if the patient has low albumin or heart condition
Differences between replacement and maintenance fluids & when to use them.
* Learning Objective*
-
fluid replacement - Na concentration is close to normal plasma Na of about 140 mmol/l
- Can give rapidly!
- Designed to replace fluid loss
- K is similar to that as plasma
- Ex. Ringers, LRS, Normosol R, 0.9 % saline, PlasmaLyte
-
fluid maintenance - Na conc is close to normal total body conc of about 70 mmol/l
- DONT give rapidly
- Designed to replce daily Na losses without Na overload
- Poor at explanding blood volume and thus often combined with colloids in patients with low albumin
- Some lack K, so you should add it
- Ex. Normosol M, 0.45 % NaCl with 2.5 % dextrose, PlasmaLyte 56
When and Why shoudl you switch to maitnance fluids when a patient is on replacement fluids?
Switch from replacement to maitenance after 24 hours
If used for longer periods, patient may become hypernatremic which can lead to swelling of the brain and then CNS signs.
If replacement fluids are used for maintenece , you should add K and should monitor serum Na.
Why would replacement fluid be used for maintenance? What problems could you encounter?
*Learning Objective*
To save money. You dont want to charge client for additional bags of fluids when they have not finished one. Also so the hospital does not have to stock as many types of fluids.
Problems: hypernatremic patient –> brain swelling –> CNS signs.
Should add K and monitor Na levels.
What are the two main groups of colloids? and why would you use them?
*learning objective*
-
(1) Natural: used when goal is to restore RBCs, clotting factors, AT III, or albumin
- Plasma: if albumin, AT III, clotting factors needed
- Whole blood: if RBCs needed – only if animal is ANEMIC
-
(2) Synthetic: used when goal is to rapidly improve perfusion in patient that does not have obvious blood loss or clotting problem. Often used in addition to regular fluid therapy.
-
Dextran -Polysaccharide
- Adv: isotonic. Stored at room temp. Increases plasma vol 1.38 x the vol. infused.
- Disadv: increase in BMBT, PTT but no clinical bleeding. Fibrinogen conc decreases. Blood glucose level may increase.
- Hetastarch: most commonly used synthetic colloid in vet med
-
Dextran -Polysaccharide
When would you use Hetastarch fluids?
Used in cases that need oncotic support but don’t need clotting factors
Increases plasma volume by 1.37% of volume infused
Most commonly used synthetic colloid- last longer than dextran in circulation.
Ex: Cases with low albumin (vasculitis, PLN, PLE, liver failure, sepsis, etc)
Contraditions: heart failure & cats get restless and/or salivate
What is acontraindication of using hetastarch fluids?
Heart failute
Some cats get restless and/or salivate
What are potential side effect of colloids?
Fluid overload and pulmonary edema
Coagulopathy
Renal failure
Human albumin: could cause life threatening allergic reaction in dogs
What should you first use to correct dehydration?
Isotonic Replacent fluids which can be given rapidly
Why is using replacement fluids for maitnance usually not a serious clinical problem? In what cases would it be a problem?
Because most patients with functioning kidneys will simply increase renal sodium loss to compensate when hypernatremic.
big problems occur when impaired kidney function and if Na >170 –> Salt toxicity–> swelling of brain –> CNS signs
Can I combine colloids and crystalloids in dehydration or shock cases?
* Learning objective*
YES! But remeber….
- Colloids are not used to replace dehydration deficits because you need crystalloid to get into interstitial and intracellular spaces
- Colloids are helpful to keep fluids in intravascular space so used in cases with low albumin or vasculitis or those with peripheral edema or ascites.
- By combining both you decrease the amount of crystalloid you have to use and restore the fluid deficit of intravascular space more rapidly.
What would be your fluid therapy plan for a 6kg dog with 10% dehydration from diarrhea and a low serum ablbumin at 1.5 mg/dl?
- Start replacement crystalloid to correct for dehydration
- Piggy-back a colloid (plasma would be good choice, but could use hetastarch if you didn’t have plasma).
- Once you calculate the mls of colloids you will be using, subtract that number from the calculated dehydration deficit. By using colloid, you decrease the amount of crystalloid you have to use.
- If you gave only replacent fluids you run the risk of those fluids causing peripheral edema/ascities/pleural effusion because of the low oncotic pressure from low albumin
What would be your concerns when providing fluid therapy to a cardiac patient? Which fluid is best to use?
-
Beware of using high Na-containing fluids (replacement fluids) to patients with known or suspected cardiac disease.
- The high sodium load can unmask pre-clinical congestive heart failure, as water follows sodium, and volume overload can result.
- The ‘classic’ fluids for a cardiac patients are 0.45% NaCl (as opposed to 0.9%) and are made isotonic through the addition of dextrose.
What is the classic fluid to use in patients with cardiac issues?
0.45% NaCl that is made isotonic through the addition of dextrose.
Why should you add K to fluids?
How do you determine how much K should be added?
How rapidly can you give fluids with K added?
Due to obligate renal K loss, patient who are not eating will become hypokalemic within dats.
The amount added is based on the patients existing K levels and the “sliding scale of scott”
**NEVER give more than 0.5 mEq/kg/hr (Kmax)**
Sliding Scale of Scott
Chart/Table that helps detemine how much K to add to a liter of fluids based on the patient’s current K levels.
If have only 1/2 a bag of fluids, just add half as much that is indicated!
Never give more than the Kmax = 1/2 of the animals body weight= 0.5 mEq/kg/hr
K max
** VERY IMPORTANT for class and OSCE**
0.5 mEq/kg/hr
half of the body weight (kg)
Never give more due to life threatening hyperkalmia can result in death
When should you use Hypertonic saline?
(1) large dogs that are in shock due to gastric dilatation-volvulus;
(2) patients that should not receive large volumes of fluid , e.g. those with head trauma or cerebral edema
Hypertonic saline pulls fluid into vascular spaces from interstitial and intracellular spaces (short lived).
Used to replace volume deficit with less fluid in hypervolemic shock and improves blood flow. It is useful in patient that need to recieve a large amount of fluid quickly.
Hypertonic saline is normally diluted with a colloid solution to 7% (Ex. To achieve a 7.5% dilution, add 17 ml of 23% hypertonic saline solution to 43 ml of a colloid solution in a 60 ml syringe.)
Never give to a dehydrated animal!
What are indication and contraindication to use hypertonic saline? What are side effects?
-
Indications of hypertonic saline:
- Cases of hypovolemic shock that do not have dehydration or hypernatremia
- Head trauma cases
-
Contraindications of hypertonic saline:
- Dehydration
- Hypernatremia
-
Side effects
- Rapid administration may cause bronchoconstriction, bradycardia & hypotension
- Dose: Over a 20-minute period, dogs should receive 4 to 7 ml/kg; cats ½ this dose.
Tell me about enteral administration of fluids
Used in mild dehydration
ONLY IF the GI function is normal (no vomit), airway is controlled and if mental status is ok.
Common in large animals
When would you use intraosseuous administration of fluids?
In pediatric and/or severly dehydrated patients.
Usually femur (trochanteric fossa) or humerus (greater tubercle)
When do you use IV?
For dehydration and shock
When would you use sub-q route for fluid therapy? What are things to consider?
Most commonly in chronic renal failure or parvo puppy that cannot pay to stay in hospital.
DONT swab with alcohol or use fluid with glucose
Will want to warm isotonic fluids in warm water before giving.
What is a cut down?
cutting the skin over a vein so you can see it…
What perfusion parameters should you monitor during fluid therapy?
*** KNOW THESE!!****
Perfusion parameters: HR, CRT, MM, Pulse
pressure, temperature, blood pressure
** KNOW THESE***
How much does 500 ml weigh?
1 pound = 500 ml
Weight is a good indication if you are correctly/keping up with fluid loss.
What is dehydration?
What are causes? clinical signs?
Fluid loss from intracellular &/or interstitial spaces; occasionally the vascular space (in that order). Loss of total body water
Causes: inadequate water intake, excessive fluid losses from vomiting, diarrhea, polyuria without compensatory polydipsia, peripheral edema
Signs: – Decreased skin turgor – Tacky or dry mucous membranes – Sunken eyes
What are the clinical signs of
Subclinica- undetectable
What are the clinical signs of 5-7%/Mild dehydration?
Mild dehydration = 5-7% (7%)
Subtle loss of skin elasticity
tacky mucous membranes
What are the signs of Moderate (8-11%) dehydration?
Moderate dehydration = 10%
Prolonged skin tent
Tacky MM
Signs of volume depletion
Proloned CRT (CRT >2 sec)
What are clincal signs of severe (12-15%) dehydration?
Severe dehydration = 13%
Skin tent stands in place
Tacky MM
Sunken eyes
>2 sec CRT
depressed
Maybe signs of shock (tachycardia, poor pulse)
What is the difference between shock and dehydration?
Dehydration: fluid loss from intracellular & /or interstitial space; sometimes vascular space if severe dehydration
Hypovolemic shock: fluid loss from vascular space. Results in inadequate oxygen delivery to tissues.
How do you calculate the dehydration deficit in liters ?
Fluid deficit in liters = % dehydrated x body weight in kg
– Ex: 10 % dehydrated x 10 kg = l liter needed
How do you calculate the daily maintenance fluid?
Some differences in formulas. 40-60 mL/kg/day (dog high end; cat low end).
During fever, the maintenance rate increases an extra 15-20 mL/kg/day (total 55-80 ml/kg/day)
Has to be given over 24 hours, even if the patient wont be there the whole time
How do you calculate the ongoing fluid losses?
Estimate of losses that occur from diarrhea, vomiting, polyuria, or ‘third space’ sequestration.
Some use the same number as daily maintenance and then just double it.
What do you do if you have to give IV fluids over a shorter period of time? (less than 24 hours)
Give 50% of the dehydration deficit over 4-6 hours.
Then give the remaining 80%-100% of the remainder of the dehyration deficit fluid over the next 6 ish hours.
Maintian daily maitnance and ongoing fluid loss rates on a 24 hour basis.
What should you do if your patient is staying over night for fluid therapy, but you are leaving in 4 hours?
Give 50% of the dehydration deficit fluid amount over 4 hours. Re-asses, then give the remainder of the dehydration deficit fluid amount over the remaining 20 hours (if no changes upon re-assesment)
Keep maitnance and on-going loss amounts on 24 hours basis.
How much should fluid should a 10kg dog that is 10% dehydrated get?
1L or 1000 ml
(ideally over 24 hours)
Do you Understand the differences between fluid calculations for dehydration, maintenance, and on-going losses?
Dehydration deficit
Fluid deficit in liters = % dehydrated x body weight in kg
Can give over 6-24 hours. Re-asses as needed.
Daily maintenance:
40-60 mL/kg/day (dog high end; cat low end).
During fever, increase an extra 15-20 mL/kg/day.
Give over 24 hours
Ongoing fluid losses:
– Measure the losses (catheter, measure the vomit, weigh pee pad) –or– estimate by doubling maintenance.
Give over 24 hours. Re-asses as needed.
What is the shock dose for a dog and cat? How should you give it?
Shock fluid dose: 90 ml/kg/hr dog; 45-60 ml/kg/hr cat.
Give 1/4 of the dose within 15 minutes then reasses.
Can calculate 1/4 of dose simply by adding a zero to the animals weight in pounds to get the mls of fluid
(represent the total blood volume)
What fluids should you give in shock?
Replacement crystalloids
Sometimes hypertonic saline in GDV or head trauma HBC patient. (NOT when dehydrated or if cardiac issues)
CASE 3:Calculate amount of fluids needed to correct 13 % dehydration in a 5 kg cat.
– How rapidly would you administer those fluids?
– What type of fluids would you choose to give if the cat had a serum K of 3.0 mEq/L (normal 4.2-5.4 mEq/L)
– If you added K to your fluids, at what rate can you administer those fluids now?
See Answer Key
CASE 4: A 15 year old, 10 kg, dog with a history of heart failure was hit by car (HBC).
– If it is in shock, what parameters will you be looking for to confirm shock?
– What is the calculated shock dose for this dog?
– How rapidly would you administer the fluids?
See Answer Key
Case 5
• A 5 year old, 20 kg, dog has an albumin of 2.3 mg/dl because of a protein-losing enteropathy. It has been having diarrhea severe enough to result in 7 % dehydration.
– What type of fluid(s) would be best to use in this case?
See answer key
What are the 5 classifications of circulatory shock?
Hypovolemic (hemorrhagic, non-hemorrhagic, redistribution)
Cardiogenic
Vasodilatory or Distributive
Obstructive
Combination of above
Compare hemorrhagic, non-hemorrhagic and redistribution causes of hypovolemic shock
Hemorrhagic- blood loss (ususally >15% of blood volume)
Non-hemorrhagic - vomit, D, wounds, burns, polyuria
Redistribution- fluid shift to body cavitis, bowel, peripheral tissues.
Causes of Cardiogenic Shock
Due to:
(1) Acquired heart disease (myocardial trauma, myocarditis, pericardial tamponade, arrythmias)
(2) Congenital heart disease
(3) Anesthetic overdose
Causes of Obstructive Shock
Obstruction to flow: GDV, pericardial effusion, venous thrombosis, tension pneumothorax
USUALLY obstruction of venous return (as in GDV), but sometimes it is arterial obstruction (e.g. saddle thrombus)
Rx: relieve obstruction and use IV fluids
Cause of Vasodilatory or distrutive shock?
Sepsis and Septic Shock
What are the two phases of Sepsis, endotoxemia, septic shock?
What happens in the compensated stage of shock?
What happens during the decompensated stage?
What are the clinical signs of hypovolemic and cardiogenic shock?
Do I give shock dose if dog has low albumin?
YES!
Piggy back colloids onto it.
Responses to Dehydration
Volumeis regulated by adjusting [Na+]= Influenced by changes in vascular pressure
- Renin-Angiotensin-Aldosterone System (RAAS)
- Aldosterone acts on the kidney to conserve Na and excrete K. Water will follow Na abck into the body.
- ADH will also be released for hypovolemia
- Osmolalityis regulated by adjusting H2O balance.* = Influenced by 1-2% change in osmolality
- ADH release –> Thirst & ↑ H2O resorption from the kidney
Potassium in Diarrhea
K is lost in diarrhea but this loss may be masked when there is a loss of bicarbonate and thus an acidosis. This is because the excess H will enter cells in exchange for K, thus masking the total body deficit
if you have a single older cow in a large herd presenting with weight loss, muscle atropy and intermittent diarrhea, what is your top diagnosis? What kind of diarrhea is it?
Johnes Disease!!!
Exudative diarrhea (increased permeability) *** & Osmotic diarrhea (secondary) due to the diffuse granulomatous enteritis and proliferation of macrophages that will result in mucosal damage and inflamamtion. Loss of the normal epithelial lining / tight junction causes an increase in permeability and passive loss of fluid. Protein losing enteropathy
Have diffuse granulomatous enteritis in the ileum/ ileocecal area as well as local lymph node involvement (enlarged ileocecal lymph node)
Cattle are infected when they are younger than 6 months, then only a few present with the chronic condition. If in herd, you should test and cull carriers.
In sheep/goats you will have a granulomatous lymohangitis with lymphangiectasia (prominant lymphatics vessels)
Other DDx would be neoplasm of the GI tract
Turkey/Chicken- also with yellow diarrhea, inappetance, ruffled feather, eyes closed, dead down, blue/violet discoloration of head, combs and wattles. Animals died soon after first clinical signs.
Top DDx? What type of diarrhea is it? How do the birds contract it?
Black Head/ Histomoniasis
Increased permeability/Exudative diarrhea
Vectored by Heterakis (chicken ascarid)
More common in chickens, but the disease is less severe. You should not house chickens and turkeys together.
Lesion in the Liver and cecum. Yellow multifocal to coalescing eosinophilic, granulomatous, necrotising hepatitis. Cecum is enlarged, yellow, and contains a course, fibronecrotic material in the lumen of the cecum, typhlitis. Secondary infections will increase the lesion severity.
Initially in gap healing, Osteoblasts deposit laminar bone in fracture gap _________to long axis
perpendicular
