Introduction to IV fluids Flashcards
IV fluids are:
- Isotonic if between
- Hypotonic if
- Hypertonic if
- 240 and 340 mOsm/L
- less than 240
- > 340
Intracellular normal volume?
In osmotic equilibrium in normal circumstances (28L)
What are the types of extraceullualr fluid? 3
- Intravascular
- Intersititual
- Third space or transcellular
Describe each of the following:
- Intravascular
- Intersititual
- Third space or transcellular
- Three examples of transcellular space?
- Intravascular (AKA plasma… fluid contained within the circulatory and lymphatic system (3.5 L)
- Interstitial: Fluid that is found outside the circulatory/lymphatic system that surrounds tissues…aka “tissue space” (10.5 L)
- Third space or transcelluar: spaces where fluid does not normally collect in large amounts…
- CSF,
- joint spaces,
- vitreous humor
What are colloids?
Fluids containing larger molecular weight (>8000) proteins and molecules with plasma oncotic pressures similar to normal plasma proteins. Large molecules that don’t pass through cell membranes.
- When colliods are infused they remain where?
2. What do they do there? 2
When infused,
- they remain in the intravascular compartment and
- expand the intravascular volume and
- they draw fluid from extravascular spaces via their higher oncotic pressure
What colliods are used as volume expanders?
3
- Albumin
- Plasma protein fraction…Plasmanate
- Synthetic colloids…Dextran, Hetastarch
- WHat are crystalloids?
2. This will increase the fluid volume where? 2
- Fluids with molecular weight less than 8000 and low oncotic pressure: Hypotonic, Isotonic, and Hypertonic
Contain small molecules that flow more easily across the cell membranes, allowing for transfer from the bloodstream into the cells and body tissues.
in both the
- interstitial and
- intravascular spaces (Extracellular)
Crystalloids: Describe the following solutions:
1. Hypotonic?
- Isotonic?
- Hypertonic?
- a solution of lower osmotic pressure than blood
- noting or pertaining to a solution containing the same salt concentration as blood
- a solution of higher osmotic pressure than blood
What will a hypotonic crystalloid solution cause fluids in the body to do? (know)***
Which solutions are these? 2 (know)***
Will cause fluids to leave the vasculature for the Interstitial and intracellular spaces
- 0.45% NS (1/2 NS)
- And D5W (after infusing- you metabolize the dextrose super quick and it become hypertonic).
Hypotonic crystalloid solutions lowers the serum osmolality within the 1._______ _____, causing fluid to shift from the 2.__________ space to both the 3._________ and 4.________ spaces.
These solutions will 5._______ cells, although their use may 6._______ _____ within the circulatory system.
- vascular space
- intravascular
- intracellular
- interstitial
- hydrate
- deplete fluid
TYPES OF HYPOTONIC FLUIDS?
4
Hypotonic fluids are used to treat patients with conditions causing intracellular dehydration, when fluid needs to be shifted into the cell , such as: 3
- 0.45% sodium chloride (0.45% NS),
- 0.33% sodium chloride,
- 0.2% sodium chloride, and
- 2.5% dextrose in water
- Hypernatremia
- Diabetic ketoacidosis
- Hyperosmolar hyperglycemic state.
Precautions with hypotonic fluid?
2 general precautions and 4 specific
- Never give hypotonic solutions to patients who are at risk for increased ICP because it may exacerbate cerebral edema
- Don’t use hypotonic solutions in patients with liver disease, trauma, or burns due to the potential for depletion of intravascular fluid volume
- ICP
- liver disease
- trauma
- burns
The decrease in 1._______ ____ _________ can worsen existing hypovolemia and hypotension and cause 2._________ ______?
In older adult patients, 3.________ may be an indicator of a fluid volume deficit.
- What should we instruct pts to tell us, if they feel?
- vascular bed volume
- cardiovascular collapse
- confusion
- Instruct patients to inform you if they feel dizzy or just “don’t feel right.”
- Isotonic crystalloids are what?
- What does it increase?
- ANd what does it not affect?
What are examples of these solutions?
3
- noting or pertaining to a solution containing the same salt concentration as blood
- Increases vascular volume
- Doesn’t result in any significant fluid shifts across cellular or vascular membranes
- 0.9% NS (normal Saline)
- Lactated Ringer’s (LR)
- D5W (before infusion)
- Hypertonic crystalloids are what?
- Where will it draw fluid?
- What are examples of these solutions? 5
- a solution of higher osmotic pressure than blood
- Will draw fluids from the cells and interstitial spaces into the vasculature
- IV Fluids:
- 7.5% NS
- D5 in ½ NS
- Dextrose 5% in NS
- Dextrose 10%
- D50
- What are hypertonic solutions?
Whats osmolarity usually? - The osmotic pressure gradient draws water out of where and into where?
- Because of this they are used as?
- Solution that have a higher tonicity or solute concentration.
- Hypertonic fluids have an osmolarity of 340 mOsm/L or higher - The osmotic pressure gradient draws water out of the intracellular space, increasing extracellular fluid volume,
- so they are used as volume expanders.
Some examples of hypertonic solutions?
2
1- 7.5% sodium chloride (7.5% NS):
2- 5% Dextrose with normal saline (D5NS)
Hypertonic solution Indications:
1- 7.5% sodium chloride (7.5% NS)? 2
2- 5% Dextrose with normal saline (D5NS)? 1
- May be prescribed for patients in critical situations of severe hyponatremia.
- Patients with cerebral edema may benefit from an infusion of hypertonic sodium chloride
- which replaces sodium, chloride and some calories
Precautions with hypertonic fluids:
- Hypertonic sodium chloride solutions should be administered only in what?
- Maintain vigilance when administering hypertonic saline solutions because of their potential for causing what? 2
- On what time line should we be giving this?
- Prescriptions for their use should state what? 4
- Where is it better to store hypertonic sodium chloride solutions?
- high acuity areas with constant nursing surveillance for potential complications .
- intravascular fluid volume overload and pulmonary edema.
- shouldn’t be given for an indefinite period of time.
4.
- the specific hypertonic fluid to be infused
- the total volume to be infused
- infusion rate
- length of time to continue the infusion
- It is better to store hypertonic sodium chloride solutions apart from regular floor stock IV fluids .
Therefore, what category are the following:
- 0.9% NS?
- 0.45% NS?
- D5 0.45% NS?
- D5W?
- LR (RL)?
- iso
- hypo
- hyper
- iso then hypo
- iso
State Volemic Effect of 1 L of the following Fluid on intracellular, intersititial and plasma fluid Compartments:
- D5W?
- NS or LR?
- 7.5% saline?
- 5% albumin?
- WHole blood?
D5W:
Intra- 660 ml
Interst. - 255ml
Plasma - 85ml
NS or LR:
Intra- -100 ml
Interst. - 825 ml
Plasma - 275 ml
7.5% saline:
Intra- -2950 ml
Interst. - 2960 ml
Plasma - 990 ml
5% albumin:
Intra- 0
Interst. - 500 ml
Plasma - 500 ml
Whole blood:
Intra- 0
Interst. - 0
Plasma - 1000ml
We can divide the need for IV fluid therapy into two somewhat simplistic areas. What are they?
- Maintenance Therapy
2. Replacement Therapy
What types of imblaances are replacement therapies used for?
2
- Mechanical imbalances
2. Electrolyte imbalances
WHat are examples of mechanical imbalances?3
- Hypotension due to hemorrhage
- Hypotension due to anesthesia
- Excess fluid loss….due to vomiting/diarrhea/decreased oral intake
Two key concepts to remember about fluid homeostasis
- The kidney is the primary manager of body fluid levels
2. Sodium (Na) is the most osmotically active electrolyte in the body
What two kidney issues can complicate IV fluid treatment?
2
- Underlying renal disease complicates things
2. Poor renal perfusion complicates things
The kidney is the primary manager of body fluid levels: When determining fluid status, it is important to note:
3
(Whats the most important?)
- Urine output***
- Serum Sodium
- Urine osmolality (easiest as urine Na)
What other things are importnat but do not replace urine output, serum sodium and urine osmolality in our decision making? 3
- Edema
- BP
- Orthostatic vitals
Whats the difference between maintenance therapy and fluid resuscitation?
Maintenance therapy: replaces normal ongoing losses
Fluid Resuscitation: corrects any existing water and electrolyte deficits.
Maintenance therapy is usually undertaken when the individual is not expected to do what?
to eat or drink normally for a longer time (eg, perioperatively or patient on a ventilator)
- What is the goal of maintenance therapy?
- Whats the easisest way to monitor net gain/loss of fluids?
- What does a normal serum sodium tell you?
- Normal adults have an obligate fluid loss of what per day?
- Goal is to preserve water and electrolyte balance
- Daily weights are the easiest way to monitor net gain/loss of fluids
- Normal serum sodium tells you the patient has adequate water balance but not volume balance
- Normal adults have an obligate fluid loss of 1600ml/day
A pretty good IV fluid to use for maintenance is what? (and why?)
0.45% NS + 20 mEq KCl (the kidney will regulate Na, K and H20 retention)
Water requirement increases _________ml/day for each degree fever >____C
100-150
37
How to calculate maintenance fluid flow rates?
4/2/1 rule
4 ml/kg/hr for first 10 kg (=40ml/hr)
then 2 ml/kg/hr for next 10 kg (=20ml/hr)
then 1 ml/kg/hr for any kgs over that
This always gives 60ml/hr for first 20 kg
then you add 1 ml/kg/hr for each kg over 20 kg
So: Weight in kg + 40 = Maintenance IV rate/hour
45kg patient=85 ml/hr or approx. 2L/day
Replacement or Resuscitation Therapy
- What is the goal?
- What is the type of fluid given determined by?
- Goal is to correct existing abnormalities in plasma electrolyte and volume status
- Type of fluid given is determined by the type lost and current electrolytes
- Generally, when hypovolemia occurs; the kidneys conserve what? 2
- What will this be seen as?
- What will be seen earliest as?
- What will the BUN/Creatinine ratio be?
- sodium and water
- This will be seen as increased serum Na
- Will be seen earliest as decreased urine Na ( less than 25 mEq/L)
- Normal BUN/Creatinine ratio is 10:1; with hypovolemia this will increase to > 20:1
Replacement Therapy:
1. With excessive vomiting or NG (nasogastric) suction, the patient loses what? And may develop what? 2
- With excessive diarrhea, the patient may lose what and develop what? 2
- When all else fails what should we do?
- Hydrogen ions and may
- develop metabolic alkalosis and hypovolemia
- sodium bicarbonate and
- may develop metabolic acidosis and hypovolemia
- Get ABGs (remember that serum CO2 levels are very helpful)
Obviously, hemorrhage or trauma results in loss of what? 3
- circulatory blood
- hypovolema
- shock
Hypotension with general anesthesia is NOT initially due to loss of volume; it is due to what?
loss of vascular tone which “enlarges the tank”
Hypovolemia due to decreased intake or excess excretion (sweating or hung-over):
- How much until labs are back?
- If serum Na is greater than 145?
- If serum Na is less than 138?
- Initially run at what level unless they are hemodynamically stable?
- What should we monitor?
- Gross estimate of renal perfusion is to make how much urine (minimum)?
- 0.45% NS until labs are back
- If serum Na > 145 change to 0.25% NS
- If serum Na less than 138 change to 0.9% NS
- Initially run at 125 ml/hr unless hemodynamically unstable
- Monitor electrolytes and vitals
- Gross estimate of renal perfusion is to make 30ml/hr (minimum) urine
Hypovolemia due to vomiting or diarrhea:
- How much until labs are back?
- If serum Na is greather than 145?
- Initally run at what unless hemodynamically stable?
- Monitor what?
- Gross estimate of renal perfusion?
- 0.9% NS until labs are back
- If serum Na > 145 change to 0.45% NS
- Initially run at 125 ml/hr unless hemodynamically unstable
- Monitor electrolytes and vitals
- Gross estimate of renal perfusion is to make 30ml/hr (minimum) urine
Hypovolemia due to hemorrhage:
1. What will it cause on PE? 6
How should we treat them?
- What should we give them?
- Continue this based on what?
- What do we need to give them as soon as available?
- Monitor what? 3
- Gross estimate of renal perfusion?
- Tachycardic,
- tachypneic,
- systolic bp less than 90
- pale, cool, and clammy
- confused
- cyanotic
- Bolus 1-2 LITERS 0.9% NS or LR through large bore IVs until labs are back
- Continue fluid resuscitation based on vital signs and urine output
- Packed Red Blood Cells (PRBC) as soon as available
- Monitor electrolytes, ABGs and vitals
- Gross estimate of renal perfusion is to make 30ml/hr (minimum) urine
Hypovolemia due to burns
- Treatment until labs are back?
- Continue this based on what?
- What should we consider early to maintain pressure and limit?
- Monitor what? 3
- Gross estimate of renal function?
- Bolus 1-2 LITERS 0.9% NS or LR through large bore IVs until labs are back
- Continue fluid resuscitation based on vital signs and urine output
- Consider Albumin early to maintain pressure and limit edema
- Monitor
- electrolytes,
- ABGs and
- vitals - Gross estimate of renal perfusion is to make 30ml/hr (minimum) urine
Correction of existing abnormalities in volume status or serum electrolytes (as in hypovolemic shock)
What are the some parameters used to assess volume deficit? 4
1- Blood pressure
2- Urine output
3- Jugular venous pressure
4- Urine sodium concentration
How to know that the patient has Hypovolemic Shock?
The patient has the following signs and symptoms:
9
1- Anxiety or agitation 2- Cool, Pale skin 3- Confusion 4- Decreased or no urine output 5- Rapid breathing 6- Disturbed consciousness 7- Low blood pressure 8- Low body temperature 9- Rapid pulse, often weak and thready
Rate of Repletion of Fluid deficit.
1- Severe volume depletion or hypovolemic shock?
2.- Mild to moderate hypovolemia?
1- Severe volume depletion or hypovolemic shock:
Rapid infusion of 1-2L of isotonic saline (0.9% NS) as rapidly as possible to restore tissue perfusion
2- Mild to moderate hypovolemia:
Choose a rate that is 50-100mL/h greater than estimated fluid losses. calculating fluid loss.
How should we calculate fluid loss in order to treat mild to moderate hypovolemia?
4 components
- Urine output= 50ml/h
- Insensible losses = 30ml/h
- Additional loss such as
- Vomiting or Diarrhea or high fever (additional 100- 150 ml/day for each degree of temp >37 C)
Hypervolemia due to excessive accumulation of fluid in the body from?
7
1- Excessive parenteral infusion
2- Deficiencies in cardiovascular or renal fluid volume regulation
3- too much fluids in febrile phase
4- Use of hypotonic crystalloid solutions
5- Inappropriate…FFP, platelets
6- Continuation of IV fluids after critical phase
7- Comorbid condtions
Comorbid conditions that could cause excessive accumulation of fluid in the body (hypervolemia)?
3
- Congenital or ischemic heart disease
- Chronic lung and renal disease
- Obesity-fluid not calculated for IBW
Fluid Overload
Signs and Symptoms
They are not always typical but most commonly are?
8
1- Edema (swelling) - particularly feet, and ankles 2- Difficulty breathing while lying down 3- Crackles on auscultation 4- High blood pressure 5- Irritated cough 6- Jugular vein distension 7- Shortness of breath (dyspnea) 8- Strong, rapid pulse
Management of Fluid Overload
5
1- Prevention is best! 2- Sodium restriction 3- Fluid restriction 4- Diuretics 5- Dialysis
How do colloid solutions work?
Expands the intravascular volume by drawing fluid from the interstitial spaces into the intravascular compartment through their higher oncotic pressure.
- Has the same effect as hypertonic crystalloids solutions but it requires what and have what? 2
- because why?
- This affect can last how long is the capillary wall linings are intact and working properly?
- administration of less total volume and
- have a longer duration of action
- the molecules remain within the intravascular space longer.
- several days
- What is the most commonly used colloid solution?
- contains plasma protein fractions obtained from human plasma and works to rapidly expand the plasma volume used for what? 3
- What is it considered?
- Why is its use limited?
- 1- 5% albumin (Human albumin solution)
- volume expansion
- moderate protein replacement
- achievement of hemodynamic stability in shock states.
- considered a blood transfusion product and requires all the same nursing precautions used when administering other blood products.
- -It can be expensive and its availability is limited to the supply of human donors
Colloid Solutions
Albumin Contraindications: 4
a) Severe anemia b) Heart failure
c ) Known sensitivity to albumin
d ) Angiotensin-converting enzyme inhibitors ( ACEI) should be withheld for at least 24 hours before administering albumin because of the risk of atypical reactions, such as flushing and hypotension
- What is another form of hypertonic synthetic colloids used for volume expansion?
- What does it contain and what is it used for?
- Why are its advantages over albumin? 2
- 2- Hydroxyethalstarches
- Contain sodium and chloride
- used for hemodynamic volume replacement following major surgery and to treat major burns
- Less expensive than albumin and their effects can last 24 to 36 hours
Precautions when using Colloid solutions:
7
- The patient is at risk for developing fluid volume overload
- As for blood products, use an 18-gauge or larger needle to infuse colloids.
- Monitor the patient for signs and symptoms of hypervolemia,
- Closely monitor intake and output.
- Colloid solutions can interfere with platelet function and increase bleeding times, so monitor the patient’s coagulation indexes.
- Elevate the head of bed unless contraindicated.
- Anaphylactoid reactions are a rare but potentially lethal adverse reaction to colloids.
Monitor the patient for signs and symptoms of hypervolemia using Colloid solutions with what?
3
- Increased BP
- Dyspnea or crackles in the lungs
- Edema.
- What is the usual IV fluid of choice? (WHat kind of solution is this?)
- The only use for D5W as a stand alone fluid is what? 2
- Patient fluid needs are how much per day?
- Usual IV fluid of choice is normal saline (0.9% NS)-isotonic
- The only use for D5W as a stand-alone fluid is when
- serum Na is >145 and
- patient is symptomatic with hypernatremia (almost never) - Patient fluid needs are about 1600ml/day (obligate fluid loss) plus any urine output over 500 ml plus any measured or quantified loss (diarrhea, vomiting, NG suction, drains, or bleeding) [Don’t forget increased need with fever = 150ml per degree C over 37]
What is Lactated Ringer’s RL?
What is it the fluid of choice for? 2
Lactated Ringer’s (LR): Isotonic and also a fluid of choice for volume depletion due to
- trauma
- burns
- 0.45% NS (Half-Normal Saline) is what kind of solution and used for what?
- 0.25% NS (Quarter-Normal Saline) is what kind of solution and used for what?
- Albumin/Dextran is what kind of solution and used when?
- Hypotonic and may be useful until serum Na comes down and in maintenance
- Very hypotonic and used only when serum sodium is very high
- Colloid with special use only
If patient is dehydrated how does this manifest?
8
- Tachycardia,
- weak pulses
- postural hypotension
- Flushed, dry skin
- Dry mucous membranes
- Decreased urine output
- Increased hematocrit
- Increased serum sodium level
What should we do first before we give IV fluids? 4
1. Do Orthostatic VS (Tilts) Get a 2. CBC, 3. CMP, and 4. UA
Pt is considered to be Tilt positive if they have a change of how much with pulse and how much in systolic blood pressure?
Patient is considered to be “Tilt Positive” or “tilting” if he/she has a change of 15 bpm with pulse AND decrease of 10 in the systolic B/P.
- In a dehyrdated pt what IV fluid should we start and over what period of time?
- Do we do this before or after we get labs?
- We should not stop the IV until what?
- Then start 1 L NS or RL IV over approximately 1 hr.
- Adjust the fluid when you get the lab values.
- Do not stop the IV until patient can urinate
Usually I will go to the 2nd L then will slow the flow rate substantially until he/she urinates if I have not received labs yet.
What is the best marker for volume status?
Urine sodium
Hypertonic salt solution may be lifesaving in patients with what?
2
- severe dilutional hyponatremia and in
2. trauma patients when blood is not readily available…..but rarely used
0.9% sodium chloride (Normal Saline) should be given when?
6
1- to treat low extracellular fluid, as in fluid volume deficit from
2- Shock
3- Mild hyponatremia
4- Metabolic acidosis (such as diabetic ketoacidosis)
5- It’s the fluid of choice for resuscitation efforts.
6- it’s the only fluid used with administration of blood products.
Where would we get fluid volume deficit from? (in which we would need NS)
3
- Hemorrhage
- Severe vomiting or diarrhea
- Heavy drainage from GI suction, fistulas, or wounds
Because 0.9% sodium chloride replaces extracellular fluid, it should be used cautiously in certain patients for fear of fluid volume overload. Which kind of pts?
2
those with cardiac or renal disease
What are the ions in lactated ringer and in what concentrations?
5
- Na- 130
- K- 4
- Ca - 3
- Cl - 109
- HCO3 - 28
Total - 273
- WHy is lactated ringer the most physiologically adaptable fluid?
- When to be used? 4
because its electrolyte content is most closely related to the composition of the body’s blood serum and plasma.
- To replace GI tract fluid losses ( Diarrhea or vomiting )
- Fistula drainage
- Fluid losses due to burns and trauma
- Patients experiencing acute blood loss or hypovolemia due to third-space fluid shifts.
- LR is metabolized where?
- What is the lactate converted to?
- Administered to pts with what kind of acidosis?
- Who can we not give LR to? 3
- LR is metabolized in the liver, which
- converts the lactate to bicarbonate.
- LR is often administered to patients who have metabolic acidosis… not patients with lactic acidosis
- Don’t give LR to patients with
-liver disease as they can’t metabolize lactate
-severe renal impairment because it contains some potassium
-LR shouldn’t be given to a patient whose pH is greater than 7.5
Be aware that patients being treated for hypovolemia can quickly develop ________(fluid volume overload) following rapid or overinfusion of isotonic fluids.
hypervolemia
- What is NS 0.9% NaCl used for mostly?
- LR?
- D5W?
- D5 1/2 NS (D5NS) 2 -What do we need to remember about giving this?
- WHo can we not give D5W to? Why?
- expand volume
- dilute medications
- keep the veins open
- Fluid resuscitation
- isotonic to hypotonic in the body
4.
- Na and volume replacement
- -GO SLOW and monitor BP, pulse and lung sounds. Also Urine output and serum Na
- infants or head injuries
- can cause cerebral edema