Medications and Hemodynamics (Powerpoint 2) Flashcards
on the CVP waveform, what do “a”, “c” and “v” waves represent?
It is important to remember that….
And a helpful trick to find the waves is…
a = atrial contraction
c = closure of tricuspid valve
v = atrial filling
Mechanical events will follow electrical.
Look for the “R” wave on the ECG. Right before it is the atrial contraction, or “a” wave.
What can cause higher “a” waves on the CVP waveform?
atrial stenosis
dyssynchrony with ventricles –> RA contracting against a closed tricuspid valve.
What will cause the absence of “a” waves on the CVP waveform?
atrial fibrillation –> low atrial pressures
What will cause large “v” waves on the CVP waveform?
Noncompliant atria
Tricuspid regurg
Ventricular ischemia/failure.
Normal stroke volume
60-100 mL/beat
Formula for stroke volume?
SV = CO/HR x 1000
Normal SVI?
33-44 mL/beat/m^2
Normal SVR
800-1200
What is the cause of low HR?
Ischemia to the RCA. (Remember, RCA supplies SA and AV nodes)
What is the effect of glycopyrrolate
It is an anticholinergic that inhibits the parasympathetic nervous system, increasing the HR.
What are the benefits of slower HR?
Inproved coronary perfusion, increased filling, decreased myocardial oxygen demand
Where are the Beta-1 Receptors? What do they do?
Located in the heart, when stimulated, the beta-1 receptors increase HR and contractility.
Where are the Beta-2 receptors located? What do they do?
Beta-2 receptors are located in the lungs and arteries of skeletal muscles. When stimulated, they cause bronchodilation and vasodilation of skeletal muscle.
Where are the alpha-1 receptors? What do they do?
Alpha-1 receptors are located on the vascular smooth muscle. When stimulated, they cause vasoconstriction.
ESMOLOL What receptors does it act on? What is the half life? Time of onset? Loading dose? Effects on CO, BP, HR, MVO2 and PAP?
B1 receptors, B2 at higher doses. 9 minutes 1-2 minutes LD 500 mg/kg Decreases CO, BP, HR, MVO2 and PAP
METOPROLOL
What receptors does it act on?
What is the half life?
B1 blocker, B2 at higher doses.
1/2 life is 3-4 hours, maximal response in 20 min.
AMIODARONE Indication? Mechanism of action? Effect on SVR and CO? What does it do to digoxin and coumadin levels?
Indication - ventricular/atrial dysrhythmias
It increases conduction time in cardiac cells
Decreases the SVR, Increases CO
Increases dig and coumadin levels
DIGOXIN
Useful in what type of patient?
Adverse drug reaction?
Effect on HR, CVP, PAOP, SVR and CO?
Useful in patients with AF and CHF (because it decreases AV node dysfunction and increases contractility.)
ADR: Hyperkalemia, toxicity, heart block
Lowers HR, CVP, PAOP and increases SVR and CO.
Why does the PAD matter?
It is an indirect measure of LVEDP.
Normal PAD?
8-12 mmHg
Which type of dysrhythmia increases with age? (Atrial or ventricular?)
Atrial dysrythmias are more common with age due to atrial remodeling. Ventricular dysrhythmias are caused by ischemia, reperfusion, or electrolyte disorders and are unrelated to age.
Is hypothermia used during off-pump CABG?
No
What is the benefit of off-pump CABG?
Incidences of cognitive impairment are lower with off-pump CABG.
Why does massive blood transfusion cause hypocalcemia?
Citrate (a preservative) in blood transfusions binds to the calcium in the transfusion.
In a patient with tension pneumothorax, how will the pulmonary pressures be?
Elevated PAD and PAS
What is PVR? PVR normal values
PVR is the afterload of the RV
< 250
aldosterone
a steroid hormorne that assists in the conservation of Na+
SvO2
average saturation of O2 in venous blood (also said as the O2 left in blood after circulation to the tissues.)
normal is 60-80.
scvo2
measurement of O2 in venous blood in the SVC (reflects head and upper body)
Normal hematocrit
Male 38-48
female 35-45
clevidipine
decreases BP and SVR (arterial vasodiliator)
nitroglyclerin
venous dilator (decreases preload)
when should the nurse get an atrial electrogram?
when there is a tachycardia of unknown origin (SVT)
It is performed using the epicardial wires.
What are signs of tamponade?
EQUALIZED INTRACARDIAC PRESSURES!
High/Equalized CVP, PAD, PAOP
also, High HR, low CO/CI, highPAP, High CVP
How many times should defibrillate before starting CPR?
3x
Signs of RV failure?
High CVP, low CO, decreased/normal PAP/PAOP.
Signs of LV failure
Low CO/hypotension, tachycardia, elevated PAP/PAOP
