CLASS 6 - IV FLUIDS + DEVICES + BP Flashcards
What are the 2 types of vascular access devices?
Central + Peripheral
Describe the function Central Venous Access Devices
Dump high concentrations of fluid / meds into a major central vein such as a jugular, vena cava, or subclavian. The fluid mixes w a large amt of blood immediately and therefore is immediately diluted.
Describe the function of Peripheral Venous Access Devices
Dump fluid / meds into a small peripheral vein (usually in the arm) where they mix with a small amt of blood and remain fairly concentrated before flowing to larger veins where it is eventually diluted.
Describe peripheral IVs (PIV). And the precautions associated with them.
IV inserted peripherally into a small vein in the arm.
PIVs can only be in one place for a few days and risk infection and leaking of fluid / meds into the local tissue.
Meds mix w very little blood and must be diluted enough not to irritate the small vessel or local tissue.
We change the location of PICs every few days to prevent local skin complications.
What is extravasation?
Leaking into local tissue
Describe CVAD IVs and some precautions associated with them.
inserted by a physician and secured in place by a suture or stitch.
Can be left in place for long periods of time - if cared for properly the risk for local infection and extravasation is lower.
Must be closely cared for to prevent blood infections, local infections, and risk of bleeding from bein accidentally disconnected or dislodged (larger vessel leads to more bleeding)
What is a Peripherally Inserted Central Catheter (PICC)? Who inserts them?
Very long IV inserted peripherally in the arm by a trained PICC nurse - travels inside a vein leading back to the heart
What is considered safer: CVADs or PICCs?
PICCs. They have all the advantages of a CVAD but are safer bc it is so long, well-held in place, and has a lower risk of hemorrhage if dislodged.
PICCs are inserted peripherally but dump the drug centrally, therefore the site of insertion is far away from the heart.
What are implanted Infusion Ports? Give an example.
Ex - port-a-cath
CVADs implanted under the skin of the chest wall w/ a needle inserted to access the port.
For long-term and intermittent use, reduces risk of infection through the skin or bleeding due to a disconnected or dislodged device.
What is an isotonic fluid? What effect does it have on the cell? Give an example.
Isotonic fluids have a concentration of dissolved particles (tonicity) equal to the ICF.
Osmotic pressure is therefore the same inside and outside the cells, so they neither shrink nor swell w fluid movement.
Ex - 0.9% NaCl
What is a hypertonic IV fluid? What effect does it have on the cell? Give an example.
Have tonicity greater than ICF, therefore osmotic pressure is unequal inside and outside the cells. Hypertonic fluids draw water out of the cells into the more highly concentrated ECF, therefore the cell shrinks.
Ex - 3% Saline, 50% DW
What is a hypotonic IV fluid? What effect does it have on the cell? Give an example.
Hypotonic fluids have a tonicity less than that of ICF, so osmotic pressure draws water into the cells from the ECF (cell swells).
ex - 1/2 NS
What is a Maintenance IV?
Slow, continuous infusion of IV fluid to keep patients hydrated
What is an IV bolus?
rapid infusion of IV fluid used as a treatment rather than simple fluid maintenance
What are crystalloids?
IV fluids composed of mostly water w some NaCl, glucose, or other electrolytes added in.
What is the [Na] in 1/2 NS? Is this iso, hyper, or hypotonic? What effect will this have on the blood?
0.45%
Hypotonic
Will dilute the Na in the blood
What does the effect of any IV concentration depend on?
The patient’s blood. Does it have high, low, or normal Na levels?
What effect would 1/2 NS have on normal plasma?
Would lower Na levels and cause fluid to move into the issues resulting in edema.
What effect would 1/2 NS have on hypernatremic plasma?
1/2 NS would bring the conc of plasma NA back to normal
What effect would 1/2 NS have on hyponatremic plasma?
It would make the hyponatremia worse.
If the [Na] in the IV fluid is 3.0%, what is it called?
Hypertonic saline. It has the opposite effect to 1/2 NS.
What effect will 3% Saline have on Normal Plasma?
You would not administer 3% saline to a person with normal plasma.
It will result in dehydration (cause fluid to leave tissues and flow into vessel)
What effect will 3% Saline have on hypernatremic plasma?
3% saline will dangerously raise plasma [Na]
What effect will 3% Saline have on hyponatremic Plasma?
3% Saline may be used to treat low plasma Na and bring it back to normal.
What is the effect both Na and Dextrose have on plasma?
Increase OP.
Why does dextrose only have a temporary effect on plasma osmotic pressure?
Because it quickly moves out of the blood and into the cells for energy production.
What effect does 5% Dextrose in water (5DW) have on normal plasma?
Isotonic in the bag, but quickly becomes hypotonic in the blood once it becomes well distributed - the dextrose moves into the cells for energy production. Therefore it lowers OP in normal plasma
What effect does 10% Dextrose in water (10DW) have on normal plasma?
Less commonly used, would be deliberately given to influence glucose levels in the blood.
Used more so as a medication rather than just giving fluid. Would become hypotonic once the glucose moves into the cells just like 5DW.
Why is sterile water not an IV fluid?
Bc it would cause hemolysis of RBCs.
Describe the function of Colloid IV infusions (Plasma Expanders).
Contain larger “osmotically active” particles that tend to stay in the plasma and osmotically draw fluid into the vascular compartment.
What are Colloids?
Protein solutions such as plama and albumin
what effect does 5% albumin have on normal blood?
5% albumin is iso-osmotic to normal blood, therefore will stay in plasma and not shift much fluid
What effect does 25% albumin have on normal blood?
25% albumin is hyper-osmotic to Normal blood, therefore it will stay in the plasma and move a LOT of fluid into the plasma and out of the ISF. -> this pulls fluid into the blood and increases BP.
What is dextran composed of? What effect does it have on the blood?
- Complex synthetic sugars
- Metabolized very slowly so the effect lasts longer than dextrose
- same effect as albumin but doesn’t last as long
What is the function of Packed Red Blood Cells? What effect does it have on blood volume and blood pressure?
Expands plasma and gives concentrated RBCs for patients with blood loss.
PRBCs expand blood volume, therefore increase BP and fluid moves into tissues.
What medications might be administered after giving PRBCs to a patient? Why?
diuretics to prevent excess fluid and too high BP
What effect does administering plasma have on the blood? When is it most often used?
- Expands plasma volume
- Most often used when clotting factors are desired
What is Central Venous Pressure (CVP)?
pressure in R side of the heart as it fills w blood
What are LVEDV + LVEDP
L ventricle end diastolic volume
L ventricle end diastolic pressure
what is the relationship between volume + pressure
when v increases, p increases
If a patient is hypovolemic, how will their heart contract?
Hypervolemic?
Hypo: heart will contract weakly
Hyper: heart will contract strongly
What is the relationship between:
- HR and BP
- SVR and BP
- SV and BP
When HR rises, BP rises
When SVR rises, BP rises
When SV rises, BP rises
What is Nitric Oxide? What does it stimulate in our blood vessels/
Nitric Oxide is part of our blood vessels. Stimulates vasodilation.
What is the function of endothelin?
Endothelin stimulates vasoconstriction.
What is hypotension?
Low BP, typically below 95 / 60
What is symptomatic hypotension?
low perfusion
enough to cause light-headedness, dizziness, pre-syncope and syncope, abnormal weakness w normal activity, high risk for falls + trauma
What is Isolated Systolic HTN? Which age group is this most prevalent upon?
Sustained elevation of SBP > 140 and DBP < 90 mmHg
Widening pulse pressure
What is Primary Hypertension?
Essential or idiopathic
affects 90-95% of patients
What is secondary hypertension? What causes it? How do we treat it?
5-10% in adults, > 80% in children many causes (usually caused by diseases) therefore treatment is aimed at the underlying cause
What are the clinical manifestations of HTN?
- almost always asymptomatic
- end-organ damage
- secondary symptoms such as: fatigue, reduced activity tolerance, dizziness, palpations, angina, dyspnea
What are the complications of primary HTN?
Hypertensive heart disease - coronary artery disease - L Ventricular hypertrophy - heart failure cerebrovascular disease nephrosclerosis retinal damage
What is a hypertensive crisis? Which patients are at risk of experiencing a hypertensive crisis? What treatments can be used?
- Severe, abrupt increase in DBP > 120-130 mmHg
- Rate of increase is more important than the absolute value
- may occur in patients w a history of acute end-organ damage / injury
- emergency treatment with a vasdilator such as IV nitroprusside
What are the clinical manifestations of hypertensive emergency?
Hypertensive emergency if there is evidence of acute end-organ damage or injury
- hypertensive encephalopathy
- cerebral hemorrhage
- acute renal failure
- myocardial infarction
- heart failure w pulm edema
- severe headache w confusion + blurred vision
- seizures
- severe anxiety
- unresponsiveness
- nausea + vomiting
- severe chest pain
- SOB
What are the treatment goals for primary HTN drug therapy?
130-140 / 80-90
What lifestyle modifications can be used to treat primary HTN?
- restrict sodoium intake
- dash eating plan
- alc restriction
- regular aerobic exercise
- no smoking
- weight loss
- K+ and Ca2+ intake
What are the risk factors for primary hypertension?
- advancing age
- heavy alcohol consumption
- cigs
- diabetes mellitus
- elevated serum lipids
- excess dietary sodium
- gender
- family history
- obesity
- ethnicity
- sedentary lifestyle
- socioeconomic status
- psychosocial status
- low vitamin D
