Fluids and Electrolytes Flashcards
We are ____ % water.
_____ intracellular and _____extracellular.
60%
2/3 and 1/3
________ fluid composition is 80% _____ and 20% _____.
Extracellular
interstitial fluid
plasma
When managing patient’s fluid status, consider: (4)
- NPO deficit
- maintenance
- evaporative losses and “third spacing”
- blood loss
*
Do not give too much fluid to what patients? (2)
- renal
- CHF (increases preload, which increases contractility, causing cardiogenic pulmonary edema)
Hourly maintenance calculation:
4-2-1 rule
or add 40 if weight greater than or equal to 20 kg
4-2-1 Rule
Add 4ml/kg/hr for first ___kg
Add 2 ml/kg/hr for second ___kg
Add 1 ml/kg/hr for all weight in excess of 20 kg!
10
10
When a wound is large, or when a highly vascular mucosa is exposed during surgery (GI tract or lungs), _____ ___ can be significant.
Minimal tissue trauma (herniorraphy): ___ - ___ ml/kg/hr
Moderate (cholecystectomy): ___-___ ml/kg/hr
Severe (bowel resection): ___-___ ml/kg/hr
- evaporative losses
- 2-4
- 4-6
- 6-8
This refers to an internal redistribution of fluids, especially during large thoracic or abdominal procedures.
_______ ____ volume is depleted as inflamed tissue sequesters much fluid in the interstitial space. Replacement of this fluid is necessary to avoid organ hypoperfusion, especially in renal insufficiency.
Third spacing
Intravascular fluid
Small lap pads can hold ___ ml of blood.
Large lap pads can hold ____ ml.
10 - 15ml
100 ml
Only ___ of the crystalloid will remain in the plasma.
It follows the distribution of ______ _____, most of it passing to the ____ _____.
It cannot pass intracellularly (into the cell) because ions do not cross cell membranes.
- 1/3
- extracellular water
- interstitial fluid/tissue
______ are solutions of inorganic and small organic molecules dissolved in water.
The main solute is saline or glucose and the solution may be iso, hypo, or hypertonic.
Crystalloid
The following are advantages of_______:
safe, nontoxic, reaction free, and cheap
crystalloid
Disadvantages of crystalloid: (2)
- limited time in IV space
- edema with large volumes
Half life of crystalloids in IV space is:
30 - 60 minutes
In a balanced salt solution of 1000 ml,
- ____ ml will redistribute to the intracellular space
- ___ ml will redistribute into the extracellular space
In extracellular space, ____ will remain intravascular space.
0 ml
1000ml
1/4
Normal saline (0.9%) is:
considered ______
_____ mOsm
acidic, pH is 5.5
308 mOsm
Lactated Ringers contains what? (5)
- Na
- Cl
- K
- Ca
- Lactate
Lactated Ringers
- Acidity is ____
- _____ mOsm
low, pH is 6.5
273
Plasma-Lyte components:(4)
- Na
- Cl
- K
- Mg
Plasma-Lyte pH is _____.
7.4
Saline solution can cause _____ ____ ____.
hyperchloremic metabolic acidosis
Lactated Ringers can cause _____ _____
metabolic alkalosis (lactate –> HCO3)
Be careful with________containing solutions for renal and hyperkalemic patients.
Potassium
Use ____ in neuro cases because it is _____-osmolar and improves the visual field.
Normal saline
hyper
The _____ in LR prohibits its use in the presence of blood transfusions.
Calcium
Homogeneous noncrystalline substance consisting of large molecules dissolved in a solute. Most are dissolved in normal saline, but glucose, hypertonic saline, and LR have been used as well.
Colloid
Advantages of colloid: (3)
- Greater capacity to remain in the IV space (longer half life)
- more efficient for replacing a severe fluid deficit quickly
- smaller infused volume
Disadvantages of colloid: (3)
- Greater expense
- coagulopathy
- hypersensitivity reactions
Hextend is hetastarch in _____.
Hespan is hetastarch in ____.
LR
NS
If we have lost over ___ of the ABL (acceptable blood loss) replace with colloid, especially if the patient is starting to show hemodynamic changes.
1/3
What colloid has the longest half life?
However, it can impair ____ function.
Hetastarch
platelet
______ __improves microcirculation blood flow by decreasing blood viscosity and is often used by vascular and plastic surgeons to maintain patency of anastamoses.
Dextran 40
Dextran (mostly ___), also known as _____decreases platelet aggregation and adhesiveness.
70
Hetastarch
Distribution of 1000ml 5% colloid:
___ml in intracellular water
_____ml in extracellular water
Of the extracellular water,
___ ml in extravascular water
___ ml in intravascular water
0
1000
0
1000
Know normal lab values:
- Na
- K
- Ca
- Mg
- Cl
- HCO3
- PO4
- SO4
___ and water flow together and is the key regulator of water balance in the body.
Its measured value represents ___ rather than total body sodium.
Sodium is the most abundant cation of the ___ ____and is critical in determining the ____ and ____ osmolarity.
- Na
- TBW (total body weight)
- extracellular fluid
- extracellular
- intracellular
Hyponatremia occurs when plasma Na < ___ mEq/L
Causes: (3)
135
True loss of sodium (sweating, vomiting, diarrhea, burns, and the administration of diuretics)
Dilutional Hyponatremia: Due to an excess of TBW. This is the most common cause of hyponatremia and is not a deficiency of total body sodium!!
Causes of excess TBW= excess ADH release (stress, SNS activation, SIADH),TURP syndrome.
What percent of D5W will go:
intracellularly/extracellularly?
extravascularly/intravascularly?
2/3 intracellularly, 1/3 extracellularly
only 25% will of extracellular will remain in intravascular space
No _____ substance crosses into the intracellular space due to the lipophilic cell membrane (unless cotransported).
ionized
Hypotonic fluids can promote hyponatremia and have a _______ intravascular half life.
shorter
_____ can lead to a reduction in factor VIII and vWf, impairs plt function, and can prolong PTT.
Hetastarch
This fluid’s side effects include hypocalcemia allergic reactions < 1% and impaired lung function.
albumin
This fluid’s side effects include hypotension (common) and allergic reaction.
plasma protein fraction
KEY TERM
What EKG change would you observe in a hypocalcemic patient? (2)
long QT interval changes
heart block
