Vascular Access Pharmacology exam Flashcards
Drug half-life is defined as?
The time it takes for the drug to reach half its therapeutic effect.
Define: agonist
stimulates the cell and provides the desired effect
Define: antagonist
attaches to the cell receptor and blocks anything from stimulating the cell
Define: Pharmacodynamics
what the body does to the drug
Define: Pharmacokinetics
what the drug does to the body
Alpha 1 receptor abilities are;
vasoconstriction
in the arteries and veins
Alpha 2 receptor abilities are;
vasodilation
Indications for vascular access?
10 year of age or older
fluid replacement
drug administration
reasonable belief the patient my deteriorate and require any of the above
Contraindications for vascular access?
age 0-9
if the extremity has any of the following;
massive edema
burns
infection like cellulitis
trauma
phlebitis
thrombosis
dialysis fistula - unless vital signs abscent (DCPO skill)
what are the two types of IV access?
central and pheripheral
central IV locations?
subclavian
internal jugular
femoral
peripheral IV locations?
arms * preferred site
legs * foot veins are a last resort because of the higher probability of complications
external jugular (not WFPS)
disadvantage of peripheral IV’s?
veins could collapse in shock or hypothermia
geriatrics, pediatrics, and vascular disease patients may have veins hard to cannulate
ACF stands for?
anterior cubital fossa
antecubital fossae (AC space)
7 patient rights?
D rug
D ose
D ocument
P atient
T ime
R oute
R esponce
IV access complication
what is circulatory overload?
when too much fluid is administered
generally occurs with heart or kidney failure patients
auscultated the lungs especially in CHF and dialysis patients
IV access complication
what is pyrogenic reaction?
abrupt onset
foreign material causes fever, N/V, and shock
remove IV
IV access complication
what is infiltration?
catheter is no longer in the vein
fluid collects in the interstitial space
swelling around the site
IV access complication
catheter sheer?
can occur if you pull the catheter back over the needle
IV access complication
thrombus formation?
blood clot that remains in place can become a thromboembolism.
aspirate clot if possible
remove IV if unable to asperate
IV access complication
air embolism?
most likely with central lines
ensure air is out of tubing
tamponade veins when attaching tubing
The volume of air that the venous bloodstream can tolerate is thought to be between 200 and 300 mL. The risk is the greatest when the IV is started in the central circulation where there are negative pressures and air can actually get pulled in.
Air can enter the circulation upon insertion or when the tubing is disconnected to replace the solution or to add new extension tubing.
Accidental disconnection of the IV tubing.
If enough air enters the heart, it can impede the flow of blood which can lead to shock. S/Sx hypotension, cyanosis, weak, rapid pulse, and LOC.
Tx close the tubing, turn the patient on the left side with the head down, check the tubing for leaks, administer O2, and notified medical direction.
IV access complication
arterial puncture?
S/Sx pulsating bright red blood in the catheter hub.
Tx catheter should be removed and direct pressure applied to the site for at least five minutes (ten if the patient is on an anticoagulant).
IV access complication
necrosis?
Sloughing (separation of tissues) and necrosis (tissue death) - infiltration of some IV medications (for example Dextrose, Sodium Bicarbonate, Epinephrine, Potassium, Digoxin, Calcium, Dopamine, and Promethazine).
OH- is the chemical abbreviation for what?
hydroxide ions
define
respiratory acidosis?
retention of CO2 (pCO2>45)
which causes decrease pH (see-saw)
define respiratory alkalosis?
increased elimination of CO2 (pCO2<35)
which causes an increase in pH (see-saw)
define metabolic acidosis?
when the arterial blood HCO3- level drops below 22
which causes the pH to drop (elevator)
define metabolic alkalosis?
when the arterial blood HCO3- level rises above 26
which increases the pH (elevator)
ABG normal values?
pH 7.35-7.45 mmHg
pCO2 35-45 mmHg
HCO3- 22-26 mEq/L
pO2 80-100 mmHg
what are the three buffer systems the body uses to balance pH?
buffer system - quickest in minutes
- protein
- carbonic acid-bicarbonate buffer system
- phosphate buffer system
respiratory systems - happens in minutes
renal systems - happens in hours
pH abnormal
CO2 abnormal
HCO3 abnormal
what level of compensation is this?
partially compensated
if CO2 is moving with HCO3 then it is compensating
if HCO3 is moving with CO2 then it is compensating
pH abnormal
CO2 of HCO3 normal and the other is abnormal
what level of compensation is this?
uncompensated
pH normal
CO2 abnormal
HCO3 abnormal
what level of compensation is this?
fully compensated
pH normal
CO2 normal
HCO3 normal
what level of compensation is this?
compensated
what is plasma?
proteins-salt solution that acts as a transport medium for blood components
straw colored
90% water
assists in clotting, fighting infection, maintenance of BP
contains minerals
what are mild reactions to watch out for when a pt is receiving a blood transfusion?
restlessness
chills
headache
flushing
itching
seek advice from sending facility
what are severe reactions to watch out for when a pt is receiving a blood transfusion?
dyspnea
CP
N/V
anaphylaxis
oozing of blood from puncture site or mucous membranes
What will happen to a cell if it is placed into a hypertonic solution?
shrink
think ICP and mannitol
draws water from the cells into the vascular space
What will happen to a cell if it is placed into a hypotonic solution?
swell
think hippo
used to hydrate pts or prevent dehydration
Extracellular fluid can be broken down into interstitial and intravascular fluid
Define interstitial fluid
Define intravascular fluid
Interstitial Fluid: The extracellular fluid between the cells and outside the vascular bed (i.e., connective tissues, cartilage, and bone). (CSF and intraocular fluid)
intravascular fluid is found inside veins and arteries (blood plasma)
define osmosis
water through a semi-permeable membrane from low to higher gradient
define diffusion
movement of particles from area of higher concentration to low concentration
passive process
CO2 and O2 exchange is performed by diffusion
what is the formula for calculating IV drip rates?
V to be infused * drip factor / minutes
define shock?
inadequate tissue perfusion
heparin is what class of drug?
anticoagulant - are used to prevent intravascular thrombosis. The therapy works by decreasing blood coagulability.
tPa and TNK are what class of drug?
fibrinolytic - dissolve clots after their formation by promoting the digestion of fibrin.
Aspirin, clopidogrel, and ticagrelor are what classes of dug?
platelet inhibitor - are drugs that interfere with platelet aggregation
What are the classes of anti-arrythmics
Class I - sodium channel blockers, slow conduction.
Ia drug examples as quinidine, disopyramide (Norpace), and procainamide (Pronestyl).
Ib drug example lidocaine
Ic drug example flecainide (Tambocor)
Class II - beta-blocking agents. These reduce adrenergic stimulation of the heart; metoprolol.
Class III - potassium channel blockade, which increases the contractility. These do not affect automaticity and also have no effect on conduction velocity. These drugs are thought to cease dysrhythmias that result from the reentry of blocked impulses; amiodarone.
Class IV - calcium channel blockers. Thought to work by blocking the inflow of calcium through the cell membranes of the cardiac and smooth muscle cells; verapamil (Isoptin) and diltiazem (Cardizem, Tiazac).
define action potential
a change in membrane potential in an excitable tissue that acts as an electrical signal and is propagated in an all-or-nothing fashion
define biologic half-life
time required to metabolize or eliminate half the total amount of a drug in the body
define acetylcoline
a neurotransmitter, widely distributed in body tissues, with the primary function of mediating the synaptic activity of the nervous system
define cholinergic
of or pertaining to the effects produced by the parasympathetic nervous system or drugs that stimulate or antagonize the PNS.
define first-pass metabolism
the initial biotransformation of a drug during passage through the liver from the portal vein that occurs before the drug reaches the general circulation
define loading dose
a large quantity of drug that temporarily exceeds the capacity of the body to excrete the drug
define maintenance dose
the amount of drug required to keep a desired steady states of drug concentration in tissues
define neurotransmitters
chemicals that are released from neurons at the presynaptic nerve fiber
define therapeutic action
the desired, intended action of a drug
define therapeutic index
a measurement of the relative safety of a drug.
the closer to 1, the more dangerous example Digoxin
describe how ACE inhibitors work as a antihypertensive medication
Angiotensin II is a strong vasoconstrictor and also causes the release of aldosterone. Aldosterone contributes to sodium and water retention. By inhibiting the conversion of the precursor angiotensin I to activate molecule angiotensin II (a process triggered by ACE), the RAAS is suppressed and blood pressure is lowered; captopril (Capoten), enalapril (Vasotec), benazepril (Lotensin), fosinopril (Monopril), lisinopril (Prinivil, Zestril), and quinapril (Accupril).
describe how beta blockers work as a antihypertensive medication
Sympathetic-blocking agents may be classified as beta-blocking agents and adrenergic-inhibiting agents.
Beta-blocking works by decreasing cardiac output and inhibiting renin secretion from the kidneys. Beta-blocking drugs compete with epinephrine for available beta-receptor sites as well.
Adrenergic-inhibiting agents work by modifying the actions of the sympathetic nervous system. Arterial pressure is influenced by various mechanisms of the heart, blood vessels, and kidneys, blocking this sympathetic stimulation can reduce blood pressure. Classified as centrally acting or peripheral.
describe how diuretic work as a antihypertensive medication
Diuretics which cause a loss of excess salt and water from the body by the kidneys, are the drugs of choice in managing hypertension.
Thiazides are diuretics that work well to lower blood pressure. Many agents cause retention of sodium and water; thiazides, such as hydrochlorothiazide, may be given concomitantly (along with other drugs) to help prevent this side effect.
Loop diuretics, such as furosemide, are potent, short-acting agents that inhibit sodium and chloride reabsorption in the loop of Henle and cause excessive loss of potassium. They also cause an increase in the exertion of sodium and water. Side effects are hypokalemia and profound dehydration.
Potassium-sparing agents, such as spironolactone (Aldactone), can be effective when they are used in combination with other diuretics because they prompt sodium and water loss without a loss of potassium.
describe how calcium channel blockers work as a antihypertensive medication
Calcium Channel Blockers reduce peripheral vascular resistance by inhibiting the contractility of vascular smooth muscle. They dilate coronary vessels through the same mechanism, decreasing the oxygen requirements of the heart (through decreased afterload), and increasing oxygen supply (by abolishing coronary artery spasm). Examples; verapamil, amlodipine (Norvasc), felodipine (Plendil), and diltiazem.
describe how proton pump inhibitors work
Proton Pump Inhibitors decrease hydrochloric acid secretion by inhibiting the actions of the parietal cells. In addition, the gastric pH of the stomach is altered. Examples are esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonis), dexlansoproazole (Dexilant), and rabeprazole (Aciphex).
describe how antacids work
Antacids buffer or neutralize hydrochloric acid in the stomach. Rx hyperacidity, including peptic ulcer, gastritis, esophagitis, heartburn, and hiatal hernia. Common OTCs are Alka-Seltzer, Gaviscon, and Rolaids.
in the autonomic nervous system
the afferent and efferent nerves send signals which way?
afferent = arrive at the brain. stimulus to brain
efferent = exit the brain. brain to muscle
beta 1 receptors abilities are
increased HR (chrono trophy)
increase contractility (dromoprophy)
located in the heart
beta 2 receptor abilities are
bronchodilation
vasodilation
snow HR
location lungs
what are the five major sources for drugs
plants
chemicals
microorganisms
animals
minerals
according to the controlled substances act there are five schedule of drugs, what are they?
schedule 1 no medical use high risk of abuse = heroin
schedule 2 medical use but high abuse potential = opioids
schedule 3 low abuse potential, high likely hood of physical dependence = anabolic steroids
schedule 4 low abuse potential, may lead to dependence = benoz’s
schedule 5 low abuse potential, may lead to dependence = T3’s
