Fluids-Paulson Flashcards
Water balance in the human body:
-depends on water intake and ___
water output
Ex’s of water intake
- Ingested water
- Water in food
- Water from oxidation
Ex’s of water output
- Urine
- Skin
- Respiratory tract
- Stool
Body water:
- intracellular: about ___
- extracellular and intravascular: about ____
- 2/3
- 1/3
Intravascular compartment is called the _____
“first space”
Intracellular compartment is called _______
“second space”
____ _____ is where fluid doesn’t usually but may accumulate (pleural cavity, peritoneal cavity, edema in extracellular space)
“Third space”
We put drugs into the first space via ___
IV –> and expect it to evenly distribute to the second space
**Not always speedy
List examples of conditions that can cause third spacing
In surgery, major trauma, burns, inflammation & reaction can cause major third spacing, where fluids/electrolytes/meds aren’t bioavailable
Maintenance Therapy=
replaces ongoing losses of water and electrolytes under normal physiologic conditions via urine, sweat, respiration, and stool
–Tachypnea, fever, diuretics all ↑ maintenance requirements
Replacement therapy:
-corrects any existing water and electrolyte deficits from:
GI Skin Urinary Bleeding Third-space sequestration
IV access is often used to:
Deliver fluids
Deliver medications
Draw blood
Surgical patients are often **hypovolemic (list Ex’s)
- NPO prior to surgery
- NPO post surgery–> GI tract inhibited
- Blood loss from surgery
- Third spacing in surgery
How to Calculate Maintenance (steps)
- Calculate body weight in kg
- Calculate fluid needed over 24 hours
- 100 ml/kg for first 10 kg
- 50 ml/kg for second 10 kg
- 20 mg/kg for each kg over 20 - Divide total ml over 24 hours for a ml/hr rate
Most physiologic replacement (in normal circumstances) is D5½NS + 20 mEq K/L
Maintenance Fluids- Hourly Rate
4/2/1 rule:
- 4 ml for kg 1-10
- 2 ml for kg 11-20
- 1 ml for each kg ≥21 kg
Dehydration: If the patients starts with a deficit, need to add more than maintenance
-Estimate deficit: Dry?
3% loss (5% if < 5 y/o)
Dehydration: If the patients starts with a deficit, need to add more than maintenance
-Estimate deficit: tachycardic?
6% loss (10%)
Dehydration: If the patients starts with a deficit, need to add more than maintenance
-Estimate deficit: shock?
9% loss (15%)
Dehydration:
-Ex: 50 kg woman who is dry
- Calculate real weight (weight + 3% deficit): 51.5 kg
- Calculate maintenance: 2190 ml/day
- Add deficit: 1.5 kg = 1.5 L
- Total IVF rate: 3690/24 hours = 154 ml/hr
Replacement of Losses:
-if you have HIGH output losses from a drain or NG tube, you can ____
measure and replace ml for ml
Replacement of Losses:
-NG tube losses have high ___ levels
Cl
Replacement of Losses:
-use _______ fluid type for type of loss
appropriate
Volume Overload can happen with too vigorous resuscitation OR with _____
mobilization of third space fluids
Sx of Volume Overload
May have jugular venous distention, lung crackles, edema, dyspnea
Volume Overload: tx
fluid restriction, diuretics, or lower the rate
Ex: 70 kg Pt
-Calculate maintenance fluids hourly rate
70 kg Pt
4 x 10= 40 mL
2x 10= 20 mL
1x 50= 50
Total= 110 cc(mL) per hour
Ex: dehydration
-calculate maintenance for a 50 kg woman who is dry
-Take 3% of her normal body weight and add that into her body weight
3% of 50= 1.5–> 50 + 1.5= 51.5 kg
- 1L= 1kg
- She has 3% deficit–> so she is down by 1.5 L
- -add maintence to the deficit= total of 3690 over the course of a day/24= 154 mL/hr
Colloids:
Solute= large proteins like albumin or other molecules that remain ________
intravascular
Solute: fx?
draw water from the cells to intravascular space–> can significantly ↑ intravascular volume but also dehydrate cells
The use of colloids is _______
- *limited
- Expensive
- Specific storage requirements
- Short shelf life
Which Pt group should receive colloids?
Pt just recently had a large volume paracentesis (lots of albumin was removed), or a Pt with hemorrhagic shock (prior to blood arriving for transfusion), OR burn Pt
Risks: dehydration of cells, and overload of protein (ppl w renal failure/dz cant handle large protein loads, same w/ liver impairment
Crystalloids:
-contain?
electrolytes (sodium, potassium, calcium, chloride) as the solutes
Crystalloids are classified according to ______
tonicity (=concentration of electrolytes)
Compared to the body plasma, isotonic solution contains_____
the same amount of electrolytes as normal plasma
Compared to the body plasma, Hypertonic solution contains _____
more electrolytes than body plasma
Compared to the body plasma, Hypotonic solution contains _____
less electrolytes than body plasma
3% normal saline=
has 3% more electrolytes than normal saline
Lactated Ringer’s (LR)= isotonic crystalloid that has _____
sodium chloride, potassium chloride, calcium chloride, and sodium lactate in sterile water
What is Lactated Ringer’s (LR) designed for?
Designed as a ml for ml replacement for blood lost from trauma, surgery, burns
Lactate is converted to _______ in the liver
bicarbonate –>often used for this property
**Counteracts acidosis
(this is why Lactated Ringer’s is used)
When is Lactated Ringer’s preferred?
Often preferred if large volumes are needed for fluid resuscitation
Normal Saline (NS)= an isotonic crystalloid that contains ___% sodium chloride in sterile water
0.9%
normal saline= sodium and chloride
Normal Saline (NS) approximates _____
plasma
When can NS cause problems?
LARGE volumes cause problems –> hyperchloremic metabolic acidosis
NS is also used to ____
flush wounds
What is NS administered with?
**blood products
½ NS=
- **0.45% NaCl in water
- Hypotonic
When in ½ NS helpful?
Helpful in hypernatremic patients who do not need extra glucose (ie: diabetics)
D5W=
aka 5% Dextrose in Water
-Hypotonic
D5W is isotonic in the bag, but glucose metabolized almost immediately leaving _____
free water (**once metabolized it’s hypotonic)
Clinical uses for D5W
Helpful for rehydrating those who are hypernatremic
Which Pt population should NOT receive D5W?
Dextrose solutions NOT for uncontrolled diabetics or those who are hypokalemic
(explanation: glucose (ie dextrose) will cause insulin to be released–> insulin brings potassium into cells–> and the Pt will become MORE hypokalemic)
D5W provides ___ calories/L
170-200
D5½NS:
-helpful for ?
- Helpful for daily maintenance of body fluids, for rehydration (hypotonic solution)
- **Most common postoperative fluid
D5NS=
- what kind of solution?
- Replaces ____
- Hypertonic
- Replaces fluid, sodium, chloride
For Pts who have been administered D5NS, what should you watch out for?
**Watch for volume overload
3% Saline:
-what kind of solution?
hypertonic
3% saline:
-Used cautiously in those with _____
- *severe hyponatremia
- Remember, hyponatremia is often from an excess of fluid
3% saline:
- typically give ___-___ ml bolus
- how much does it raise the serum Na by?
50-100 ml bolus of 3% saline (raises serum Na by 2-3 mEq)
–May repeat 1-2 times
May add a slow IV infusion of 3% saline at ___ ml/hour
15-30 ml/hour
-Remember parameters for raising serum sodium
Rate of infusion:
-depends on many factors (list 3)
- Severity of volume depletion
- Condition of the patient
- Other diseases (ie: CHF)
How to determine if you were successful? (w/ fluid administration)
hint: urine output=
- Urine output–> **Ideally want 30-50 ml/hr
- BP, HR normalizing
- Mental status
- Capillary refill (1-2 seconds)
- NEED TO FREQUENTLY MONITOR THE PATIENT AND ADJUST ACCORDINGLY
How can a provider monitor the Pt and adjust fluids accordingly? (3 things)
- Physically look at them
- Frequent lab monitoring
- Vitals
