Fluids

Question 1

What do we initially assess in a trauma patient?

Answer 1

1. Respiratory – rate, effort, mucous membrane color, auscultation
2. Cardiovascular – heart rate, pulse rate and quality, mucous membrane color, capillary refill time, auscultation
3. Nervous – mental state, pupil size and responsiveness, motor function, proprioception, pain
4. Abdomen – abdominal pain, effusion

Question 2

When giving fluids, what is the maintenance dose for a canine?

Answer 2

~40-60 mL/Kg/Day (use this to correct small deficits from not eating/drinking properly)

Question 3

What should you be wary of when keeping a patient on replacement fluids for longer than 24 hours?

Answer 3

Hypernatremia

Question 4

Hetastarch is a colloid that is used in cases that need oncotic support, but don’t need clotting factors (plasma is best for that). What are some cases you would use Hetastarch for? What is it contraindicated in?

Answer 4

Used in cases with low albumin: vasculitis, PLE, PLN, liver failure, sepsis, etc. Contraindicated in heart failure

Question 5

T/F: Colliods are used to replace dehydration deficits.

Answer 5

False. You need crystalloid to get into interstitial and intracellular spaces. Colloids help keep fluids in intravascular space.

Question 6

What is the “classic” fluid choice for cardiac patients?

Answer 6

0.45% NaCl (as opposed to 0.9%) and are made isotonic through the addition of dextrose.

Question 7

T/F: Maintenance fluids have [K] similar to that of plasma

Answer 7

So FALSE!! Replacement fluids have [K] similar to that of plasma.

Some maintenance fluids lack K, thus it must be added.

Question 8

How rapidly can you give crystalloids with K added?

Answer 8

Never more than 0.5 mEq/Kg/hr (Kmax)

Question 9

Hypertonic Saline (technically a colloid), is usefull in what cases?

When is its use contraindicated?

Answer 9

Useful in GDV, head trauma/cerebral edema, hypovolemia cases lacking dehydration

Contraindicated in hypernatremia and dehydration

Question 10

What is the difference between dehydration and shock?

Answer 10

Question 11

Know this scale

Answer 11

KNOW IT

Question 12

How do you calculate dehydration deficit?

Answer 12

DD in liters = % Dehydrated x BW in Kg

Ex: 10kg dog that is estimated at 10% dehydration.

10% x 10Kg = 1 Liter needed

Question 13

How quickly do you correct a dehydration defficit?

Answer 13

1/2 (or more) of the DD in the first 4-6 hours.

Ex: 25 kg dog. 8% dehydrated.

25 kg x .08 = 2 Liters

1/2 of 2 liters given in 4 hours –> 1 liter divided by 4 = 250 mLs/hour for 4 hours

Then remaining 1 liter over the next 20 hours. So 1000 mLs/20 hours = 50 mL/hour for 20 hours

Question 14

How do you calculate maintainance?

What about if your patient has a fever?

Answer 14

Maintainance = 40(cats) - 60(dogs) mL/Kg/day

Durring fever, increase maintainance by 15-20 mL/Kg/day

Question 15

What would be the maintenance dose for our 25 Kg dog? He does not have a fever.

Answer 15

25 Kg x 60mL/Kg/Day = 1500 mL/day

so he would be getting 1500mL/24 hours = 62.5 mL/hour for maintenance.

Question 16

Lets say our 25 Kg dog has some ongoing losses due to diarrhea. We estimate it at 500 cc in 24 hours. How do you correct this as well?

Answer 16

500 mL / 24 hr = 21 mL/hr to correct on going losses.

Question 17

Now, in total how much fluids are we giving our 25 Kg dog?

Answer 17

First 4 hours: 250 DD + 63 Maint + 21 Ongoing = 334 mL/hour

Next 20 hours: 50 DD + 63 Maint + 21 Ongoing = 134 mL/hour

Question 18

How do you calculate a shock dose of a crystalloid (ringers, saline)?

Answer 18

90 mL/Kg/hour Dog

60 mL/Kg/hour Cat

So we are replacing the total blood volume per hour

Question 19

How rapidly to you administer a shock dose of a crystalloid?

Answer 19

Give 1/4 shock dose in 15 minutes (as fast as possible), then the rest over an hour or reasses patient.

Once shock is reversed, then proceed to correct DD, Maintenance and ongoing losses.

Question 20

Ex: What is the shock bolus dose for a 25 kg dog? How fast do you give it? We are giving a crystalloid.

Answer 20

25 kg x 90 mL/kg/hour = 2250 mL/hour

Give 1/4 in 15 mins –> 2250/4 = 562 mL/15 min

**Hint** you can add a zero to the weight in pounds to get a quick 1/4 shock dose*

25 kg = 55 lbs –> 550 mL/15 min

Question 21

What are the shock boluses for Hypertonic Saline, Colloids, and Blood Products?

Answer 21

1. Hypertonic saline: 4–7 ml/kg
2. Colloids (dextrans, hetastarch): 10–20 ml/kg
3. Blood products: whole (20–25 ml/kg); pRBCs (15–20 ml/kg); FFP (10–15 ml/kg)

Question 22

What are our 3 common drip sets and rates?

Answer 22

1. Macrodrip/Blood Set - 10 drops/mL
2. Regular Set - 15 drops/mL
3. Microdrip - 60 drops/mL

Other sets/rate exist. So dont freak out if you see one. It’s just a different rate.

Question 23

You need to give 1500 mLs saline IV in 12 hours. You are using a 15 drops/mL drip set. Since you work a poor clinic and lack fluid pumps, you need to calculate the drops per second so you can eyeball it. What is the drops/second rate? (gtts/sec)

Answer 23

1500 mL x 15 gtts/mL x 1/12 hours x 1 hour/60 minutes x 1 minute/ 60 seconds = 0.52 drops/ second

Can’t really give .5 drop per second so we give 1 drop per 2 seconds.

Question 24

Which fluids have K?

Answer 24

Ringers,

LRS,

Plasmalyte A,

Normosol R,

5% dextrose in Normosol M

Question 25

You are running a patient at a fluid rate of 120mL/hour and run out of electronic fluid pumps. Since the patient is relatively stable, you decide to use a 15 gtt/mL manual drop set. What is the drip rate in gtt/min?

8 gtt/min

12 gtt/min

30 gtt/min

480 gtt/min

Answer 25

30 gtt/min

120 mL/hr x 15 gtt/mL x 1 hr/60 min = 30 gtt/min

Going further, youd probaly want to calculate gtt/sec to make your life easier.

30 gtt/min x 1 min/60 sec = 0.5 gtt/sec. But since we cant measure half a drop, we can double this to 1 drop every 2 seconds.

Question 26

You are setting up fluids for a 20 kg dog undergoing elective surgery. Since you work at Ross are are concerned about a pump stopping durring a power outage, you decide to use a manual drop set to be safe. You choose a 20 drops/mL drip set becaue why the hell not? How many gtt/sec do you need to set it for?

Answer 26

20 kg x 10 mL/kg/hr x 20 drops/mL x 1 hr/60 min x 1 min/60 sec =

1.11 drops/second

You cant exactly eyeball .11 of a drop so we will round down in this case since its such a small fraction to 1 drop/sec (gtt/sec)