Physiology and Patient Assessment

Question 1

How much of animal’s body weight is water?
What % body weight due to water found in vessels? – Name compartment and importance of fluid here.
% body weight found outside vessels – name compartment. – subdivisions of this compartment?

Answer 1

60%
5% – Intravascular compartment. – oxygen and nutrient delivery and transport of waste.
55% – Extravascular compartment – Intracellular and extracellular.

Question 2

% intracellular fluid?
% extracellular fluid?

Answer 2

40%
15%

Question 3

3 main categories of fluid disturbance in unwell patients? – examples.

Answer 3

Changes in volume eg dehydration, hypovolaemia.
Changes in content eg electrolyte disturbances, changes in blood glucose, changes in blood protein levels
Changes in distributution eg third spacing.

Question 4

Term for increase fluid volume?
Define iatrogenic.
Term for decreased fluid volume?

Answer 4

Hypervolaemia
Illness caused by medical examination or treatment.
Hypovolaemia

Question 5

Difference between hypovolaemia and dehydration?

Answer 5

Hypovolaemia relates to quick loss of fluid from intravascular space, resulting in tissue hypoperfusion (shock). eg bleeding due to RTA.
But dehydration relates to slow loss of fluid from extravascular compartment and patient unable to keep up its ins and outs. There is time for fluid to be redistributed across all body compartments, resulting in water being lost equally from all compartments of the body. eg no access to food and water.

Question 6

Physiological consequences of hypovolaemia.

Answer 6

Blood loss causes pre-load to reduce, causing reduced stroke volume, causing reduced cardiac output, causing vasoconstriction (to increase TPR) and tachycardia, maintaining BP and redirecting blood flow to vital organs, causing changes in MM colour and CRT.

Question 7

What components of triage will give you info about a patient’s intravascular vol?

Answer 7

HR, pulse quality, MM colour, CRT, BP, mentation, temp

Question 8

Name the phase that begins at mild shock.
Name the phase that begins at severe shock.
Likely mentation of the patient at severe shock?
What should you be suspicious of if the HR exceeds 220bpm?
Why is a HR above 220bpm inefficient?
What could a very low HR suggest?

Answer 8

Compensatory phase.
Decompensatory phase.
Obtunded.
Tachyarrhythmia.
Diastole so short that heart cannot fill with blood properly, reducing CO.

Question 9

Why should you not rely on BP alone to determine status of patient?

Answer 9

Sys BP can remain normal even in mild to moderate shock as the patient is compensating for the fluid loss.

Question 10

Normal HR?
Normal MM colour?
Normal CRT?
Normal sys BP?

Answer 10

60-120
Pink
<2 sec
>90

Question 11

What other factor could contribute to the patient’s capillary refill time being slower?

Answer 11

Cold

Question 12

What components of triage/ physical exam will give you info about patient’s extravascular vol status?

Answer 12

MM moistness.
Skin turgor eg tenting
Weight
Globe position
U output

Question 13

What part of a cat or dog used to assess skin turgor?
What part of cattle used to assess skin turgor?

Answer 13

Head.
Above eye.

Question 14

Physical exam findings of patient with 5% dehydration?
PE findings of patient with 5-6% dehydration?
PE findings of patient with 6-8% dehydration?
PE findings of patient with 10-12% dehydration?
PE findings of patient with >15% dehydration?

Answer 14

Not clinically detectable, suspected from clinical history.
Tacky MMs, mild delay in skin tent return.
Dry MMs, mild increase in CRT, mild to moderate delay in skin tent return +/- sunken eyes.
Dry MMs, CRT >2-3 sec, signs of shock, marked prolongation/standing skint tent, sunken eyes.
Incompatible with life.

Question 15

What parameters from haematology, biochemistry and urinalysis may be affected by a patient’s hydration status?

Answer 15

Packed cell volume/total solids (increase)
Urea and creatinine (Increase)
Urine SG (increase)

Question 16

What should firstly be established before deciding if fluid administration is necessary?

Answer 16

Whether hypovolaemia is present.

Question 17

If hypovolaemia is present, what should be done?
If hypovolaemia not present, what should be done?

Answer 17

Proceed stabilisation and rapid fluid resus of patient – boluses of fluids.
Check for extravascular fluid losses. If present, correct slowly.

Question 18

Consequence of rapid fluid administration to dehydrated patients.

Answer 18

Increase blood vol, increased atrial pressures, atrial and baroreceptors trigger increased production of diuretic hormones, increasing U output, continuing to be dehydrated.
Patients with condition making it difficult to rapidly increase U output (eg with AKI) could be at risk of life threatening hypervolaemia.

Question 19

Define hypovolaemia.
Hypervol
Normovolaemia
Shock

Answer 19

Hypo-v – State of decreased intravascular volume.
Hyper-v (fluid overload) – medical condition where there is too much fluid in blood.
Normo – Normal blood volume.
Shock – A state of cellular and tissue hypoxia, commonly caused by hypoperfusion.

Question 20

Dehydration
Intravascular
Intravenous
Osmotic
Oncotic pressure

Answer 20

Dehydration – Excessive loss of body water from extravascular compartment.
Intravascular – situated or occurring within vessel(s).
Intravenous – Existing or taking place within/administering into vein(s).
Osmotic – Of, relating to, caused by or having properties of osmosis.
Oncotic pressure – Form of osmotic pressure induced by proteins, notably albumin, in a blood vessel’s plasma (blood/liquid).