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What does a crystalloid contain?
Contains sodium – no protein
What is osmotic pressure?
Osmotic pressure is the physical force that prevents fluid from moving out and through a semi-permeable membrane. So for instance, a hypotonic IV solution exerts less pressure, allowing fluid to move into the cell (where there is a higher osmotic pressure). Conversely, a hypertonic IV solution will draw fluid toward it, away from the cells. Isotonic fluid creates no net fluid movement.
What do the administration of all IV solutions carry?
The administration of all IV solutions carries certain risks, but hypo and hypertonic solutions carry risks associated with the movement of water between these semi-permeable membranes, which you can see with this depiction to the cells.
What can too much fluid in the cells cause?
Too much fluid in the cells can cause cells to swell and burst, in this illustration it is a RBC. But think about what might be happening to brain cells in the presence of excessive hypotonic administration. When brain cells swell & burst, seizures, coma & even brain herniation (soon followed by death) can ensue. Usually, we think of brain herniation in association w/ brain injury – whether this cerebral edema is secondary to stroke, tumors or head injury. So if you receive an order for a hypotonic solution for a patient with brain swelling, you may want to clarify that there is a really good reason to do this, right?
What do hypertonic solutions cause?
Hypertonic solutions cause Cell dehydration or shrinkage – there may be occasions to do this (for instance, in addressing increased ICP), or possibly severely low sodium, but rapid correction of low sodium also risks brain damage through a process known as – osmotic demyelination syndrome – which can present as ataxia, confusion, slurred speech, drooling, tremor, weakness.
What are isotonic solutions?
Isotonic solutions are the most commonly used crystalloid. Providing isotonic fluids (i.e., those osmolalities that are similar to our plasma) provide circulating volumes, supporting the body and the cells in maintaining homeostasis.
What is oncotic pressure?
A second pressure is oncotic Pressure - similar to osmotic pressure, but exerted by colloids or proteins -
Are protein and albumin often used interchangeable?
Protein & albumin are terms often used interchangeable…Colloids is an overarching term that references these big molecules (i.e. albumin or protein) that exert a pressure that can help hold onto fluid, and even draw fluid toward it.
What can patients with protein malnutrition not hold?
Patients with protein malnutrition cannot hold onto fluid in the Intravascular space…fluid just leaks out into the dependent interstitial space areas of least resistance, manifesting as swelling, often in bellies or ankles.
The most common crystalloids are what?
The most common crystalloids are Isotonic which creates no net fluid movement. These are the fluids being referenced when you hear “give a liter wide open” on medical TV shows…wide open meaning allowing it to run as fast as gravity will allow….if a HCP wrote an order for “wide open” for an adult, I would have interpreted that as 999 mL/hr on a pump, and of course a secure large gauge IV if given peripherally.
The advantages of isotonic crystalloids are what?
The advantages of isotonic crystalloids, is it allows the body to do what it’s made to do - shift fluids to compartments that need it. With fluid resuscitation, you support the hydrostatic pressure in the vascular space to get nutrients to cells and carry out waste, however, giving too much isotonic fluids creates risks of hypervolemia (ECV excess), but it is the safest.
Are hypertonic solutions a high-risk drug?
Hypertonic solutions is a high-risk drug, and should not be given faster than 100mL/hr.
Are using hypotonic and hypertonic IV solutions appropriate for fluid restriction?
Using hypotonic & hypertonic IV solutions are not appropriate for fluid resuscitation and are strictly used for specific instances.
What do colloids contain?
Contains proteins
Are colloids a plasma expander?
Plasma “expander”
Do colloids affect clotting?
Affects clotting
Examples of colloids
Albumin
Examples of colloids
Dextran
Examples of colloids
Hetastarch
What do colloids support?
Colloids support intravascular plasma expanding capacity. I would see this used – in particular with hypoalbuminemia patients with a lot of leaky edema…they just can’t hold onto fluid, and inevitably leaks out…Patients who had severe swelling, and old IV sticks would even leak serous fluid from these old IV stick sites.
What would the 25% Allbumin help?
The 25% Allbumin would help suck that in, and keep it within the vascular space. There is risk of allergic reactions & its cost is much higher when compared to crystalloids.
What do vascular surgeons use colloids with femoral bypass graft patients?
I also would see vascular surgeons use colloids with femoral bypass graft patients – It provided the bulk and thus the hydrostatic pressure to keep those toes pink & warm…plus had the added benefit of reducing risk of clotting off the graft, d/t its clotting reducing effects.
The downfall to this is the risk it would pose for those who are prone to fluid overload, like HF, unlike isotonic crystalloids, the colloids are going to stay in the vascular space, perhaps causing hydrostatic pressures that increase pulmonary capillary pressures, resulting in HF & pulmonary edema.
These type of colloids have no oxygen carrying capacity like whole blood or prcs would have.
Examples of blood
Cryoprecipitate – manage acute bleeding
Examples of blood
FFP –increase clotting factors
Examples of blood
PRBCs – increase oxygen carrying capacity
Examples of blood
Whole Blood – has lots of plasma proteins
What do you need to attention to with patients blood?
You need to begin paying close attention to your patient’s cbc, in particular white count, hemoglobin, hematocrit & platelets at a minimum. You should be trending your patient’s hemoglobin and looking for s/s r/t this lab data. Since I’ve been a nurse, the triggers to transfuse have become much more conservative…so for instance, unless there were other corroborating reasons to give PRCs for anemia, (active MI or suspicion that Hgb is going to continue to drop, as in active bleeding) a Hgb of 10 is unlikely to trigger a transfusion. Probably somewhere around 8 before transfusion is considered…again, need to look at the whole patient.
What risk does blood carry?
Carries transfusion reaction, viral and anaphylaxis risks
What does $ blood need?
$ - due to need to procure from human donors
What are most commonly used crystalloids?
Most commonly used crystalloids are isotonic
Examples of crystalloids
0.9% NaCl (normal saline)
Examples of crystalloids
Lactated Ringers solution (LR)
What does a colloid do?
Increase colloid oncotic pressure (therefore contain proteins)
What is a colloid referenced as?
Often referenced as plasma “expanders”
What may colloids affect?
May affect clotting factors through dilutional effect
Is blood biologic?
Biologic (comes from a human donor, unlike colloids)
Can blood expand plasma?
Can expand plasma, like colloids
Can some blood products improve oxygenation?
Some products improve oxygenation, some clotting
Which solution should the nurse administer with packed red blood cells?
3% NaCl
0.9% sodium chloride
D5W
0.45% sodium chloride
What is the principal ECF electrolyte?
Sodium (Na+)
What is the principal ICF electrolyte (as opposed to Na, an ECF electrolyte)?
Potassium (K+)
Other examples of electrolytes
Calcium
Other examples of electrolytes
Magnesium
Other examples of electrolytes
Phosphorus
Sodium is responsible for:
Control of water distribution
Sodium is responsible for:
Osmotic pressure of body fluids
Sodium is responsible for:
Participation in acid–base balance
Is sodium the most abundant in the ECF?
Most abundant positively charged electrolyte outside cells
What is the normal sodium range?
Normal = 135/136 to 145 mEq/L
How is sodium maintained?
Maintained through dietary intake
Foods with sodium
Salt, fish, meats, foods flavored or preserved with salt
Sodium comes in the form of what?
Sodium comes in the form of table salt, seasonings, food. Patients who are advised to use a low sodium diet, do so because they either cannot adequately process excess sodium and/or need to reduce the effect of sodium’s water-retention qualities….So patients with HTN, HF, Renal or liver failure, etc.
Hyponatremia:
serum levels below 135 mEq/L
Symptoms of hyponatremia
lethargy
Symptoms of hyponatremia
confusion
Symptoms of hyponatremia
agitation
Symptoms of hyponatremia
headache
Symptoms of hyponatremia
seizures
Causes of hyponatermia
Excess water (decreased excretion or excessive intake) Hypo-osmolality (too dilute)
Causes of hyponatermia
Some diuretics work by wasting sodium (therapeutic effect or MOA is that the water follows)
Causes of hyponatermia
Adrenal insufficiency (Addison’s)
Causes of hyponatermia
SIADH
What is the main indication of hyponatremia?
Treatment or prevention of sodium depletion when dietary measures are inadequate
How is mild hyponatremia treated?
Treated with oral sodium chloride and/or fluid restriction
How is severe hyponatremia treated?
Treated with IV NS or lactated Ringer’s solution
I just want to point out that though it may seem intuitive to give a hypertonic solution to raise sodium level, these are considered high risk, and a rapid rise in sodium is dangerous – leading to osmotic demyelination syndrome. So the conservative response is to use isotonic solutions listed above.
Is rapid NA correction neurologically dangerous?
Rapid Na correction is neurologically dangerous!
What are extreme hypertonic solutions reserved for?
Extreme hypertonic solutions usually reserved for increased ICP (brain swelling).
Serum Sodium (mEq/L) symptoms of 120 - 125
Nausea, malaise
Serum Sodium (mEq/L) symptoms of 115 - 120
Headache, lethargy, obtundation, unsteadiness, confusion
Serum Sodium (mEq/L) symptoms less than 115
Seizure, coma
Hypernatremia:
serum levels over 145 mEq/L
Symptoms of hypernatremia
Mental status & LOC changes – seizures/coma
Causes of hypernatremia
Generally indicates relative deficit of water to sodium Hyperosmolar (too concentrated) state
What would you want to do with hypernatremia?
With hypernatremia, you would want to r/o ECV deficit or dehydration: Red, flushed skin; dry, sticky mucous membranes; increased thirst; elevated temperature; decreased urine output. However, it is possible to have an elevated sodium level with normal ECV…Tube feeding without additional water boluses or enteral water infusion can cause this as well. If it’s known that intravascular status is OK (adequate pre-load), hypotonic solutions can be used carefully to improve intracellular dehydration.
What is potassium the most abundant?
Most abundant positively charged electrolyte inside cells - 3.5 to 5 mEq/L –
Potassium is responsible for:
Muscle contraction
Potassium is responsible for:
Transmission of nerve impulses
Potassium is responsible for:
Regulation of heartbeat
Potassium is responsible for:
Maintenance of acid–base balance
Hypokalemia:
less than 3.5 mEq/L
What causes hypokalemia?
Excessive potassium loss
Causes of hypokalemia
Alkalosis
Causes of hypokalemia
Diarrhea
Causes of hypokalemia
Thiazide and Loop diuretics (called – “Potassium-wasting” diuretics)
Causes of hypokalemia
Vomiting
Causes of hypokalemia
Malabsorption
ECG changes with hypokalemia
Cardiac arrhythmias (premature contractions) -supraventricular and ventricular tachycardias – the heart is “excitable”
What can hypokalemia in the presence of digoxin therapy result in?
Hypokalemia, in the presence of digoxin therapy, can result in ventricular dysrhythmias.
Potassium obtained from all kinds of foods
Fruit and fruit juices (bananas, oranges)
Potassium obtained from all kinds of foods
Watch out for salt substitutes
Excess dietary potassium excreted via kidneys
Impaired kidney (renal) function can lead to fatal K levels
Oral forms of potassium
Must be diluted in water or fruit juice
IV administration
Pain at injection site
IV administration
Phlebitis
Excessive administration
Hyperkalemia – risk of death
How must parenteral infusions of potassium must be monitored?
Parenteral infusions of potassium must be monitored closely
IV potassium must not be given at what rate?
IV potassium must not be given at a rate faster than 10 mEq/hr to patients who are not on cardiac monitors. NEVER give as an IV bolus or undiluted
