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ANPH 233
Advanced Cardio
Question | Answer |
---|---|
3 ways to maximize ventricular performance? | Alter pre load, after load and contractility |
How does increasing pre load volume affect PVR/SVR ? | Decreases PVR/SVR AND Heart rate |
How do we decreases pre load volume? | Use of diuretics OR reduction of intravascular volume |
What are two methods of altering ventricular afterload? | Vasodilator therapy & Vasopressor therapy |
When would we use vasodilator therapy? | When SVR/PVR is HIGH |
What is the result of vasodilator therapy? | Decreased SVR/PVR, decreased afterload AND decreased preload ! |
The result of stimulation of vasopressors on alpha receptors is: | peripheral vasoconstriction |
When do we use vasopressor therapy? | When SVR/PVR is LOW |
What is the result of vasopressor therapy? | INCREASED afterload, Increased SVR/PVR and increased preload |
What are two ways we can alter Contractility? | With a positive inotrope or a negative inotrope |
A Positive Inotrope ___________ the force of myocardial contractility in order to ___________ cardiac output | increases, increase (improve) |
4 examples of Positive inotrope | Dopamine, Dobutamine, Epinephrine & milrinone |
What does a negative inotrope do? | Decreases force of myocardial contractility and O2 requirements of the heart |
Examples of negative inotropes | beta blockers & calcium channel blockers |
Factors(conditions) which can cause increased PVR: | hypoxemia, acidosis, PPV/PEEP & vasoconstrictors |
Factors which can decrease PVR: | Oxygen, Nitrogen, Alkalosis & vasodilators |
Factors (conditions) which INCREASE SVR? | hypovolemia (aka compensatory vasoconstriction), certain shocks & vasoconstrictive drugs |
Factors which DECREASE SVR? | Vasodilators, morphine, certain shocks |
Normal values for CVP? | 2 - 6 mmHg |
Normal values for RAP? | 2 - 6 mmHg |
Normal values for RVP? | 20-30 / 0-5 mmHg |
Normal values for PAP? | 15-25 / 8-15 |
Normal values for MPAP? | 10-20 mmHg |
Normal values for PCWP? | 5-12 mmHg |
Normal values for PP? | 30-50 mmHg |
Normal values for MAP? | 85-115 mmHg |
Normal values for PVR? | 155 - 255 dynes*sec/cm5 |
Normal values for SVR? | 950 - 1300 dynes*sec/cm5 |
Normal EF | 50 - 60% |
Normal EDV? | 120-180 mL |
How do we increase preload volume? | Infusion of I.V. Fluids |
What are the indications for PAC? | severe cardiogenic pulm. edema, non cardiogenic pulmo. edema (ARDS), major thoracic surgery (CABG) & Septic or cardiogenic shock |
Complications of a PAC: | 1. Same as CVP (pain, bleeding, infection etc.) 2.Irritation to heart (causing dysrhythmia) 3.Perforation of heart or pulm. artery 4.Pulmonary rupture from overfilling balloon |
What do PAC's measure? | CVP, PAP, PAWP/PCWP/PAOP, PVR, SVR & C.O. |
What are the uses of a PAC? | Measure cardiac output(thermodilution), route for mixed venous sampling, administration of drugs and pacing |
How many lumens do PAC catheters have? | 4-6 |
Which part of a PAC measures cardiac output | The Thermistor Lumen |
Which part of the PAC rests in the right atrium (for CVP measurement)? | Proximal Lumen |
Where does the distal lumen rest? | In the pulmonary artery |
Which lumen measures the PAP, PCWP and obtains mixed venous samples? Why this lumen? | The distal lumen, because it is in the pulmonary artery |
When inserting a PAC, when do we inflate the balloon? | As it enters the right atrium |
When inserting a PAC, how do we know we're in the right atrium? | Pressure should read 2-6 mmHg ( CVP) |
When will the CVP wave form appear, during a PAC insertion? | Once the tip reaches the vena cava |
How do we know when the catheter is in the right ventricle? | There will be a huge pressure change/ increased wave form - and the downstroke will still come back down to zero |
How do we know when we are in the pulmonary artery w/ a PAC ? | Pressures increase by 6-15 mmHg and the down stoke DOES NOT come back down to zero |
Once in the pulmonary artery, what does the dicrotic notch on the wave form represent? | Pulmonic valve closure |
When in wedge position, what pressure is being measured? | The back pressure from the left ATRIUM |
It takes ___________ cc's to wedge a balloon. | 0.8 - 1.5 cc's |
When do PAP's increasE? | When PVR increases and when pulmonary blood flow increases |
What pressures does PA diastolic reflect? | Left atrial pressure, pulmonary venous and left VEDP |
What pressure measures left ventricular filling? (Preload) | PCWP |
Describe optimal PCWP | The pressure at which any increase shows little or no improvement in C.O. or stroke volume |
Under what conditions does the PCWP reflect the LEFT ATRIAL pressure? | blood flow must be uninterupted b/w the catheter tip and the let heart. this ONLY OCCURS IN ZONE 3 |
Which part of the breathing cycle should we measure PCWP? | end expiration |
What is a complication of PCWP measurements during PPV? | The PCWP can be OVER ESTIMATED, b/c of transmission of pos. press. to the catheter |
PCWP should be measured when pleural pressure is ___________ | zero/close to zero |
How does negative pressure affect the heart? | It INCREASES venous return AND preload ! |
What can cause increased PCWP? | Left ventricular failure, hypervolemia, Mitral valve stenosis, and technical causes |
What would be seen on an x ray w/ a PCWP > 18 mmHg? | onset of pulmonary vascular congestion |
What would be seen on an x ray w/ a PCWP > 25 mmHg? | Obvious pulmonary edema |
What can causes decreased PCWP? | Hypovolemia (blood loss) or shock ! |
What 3 things do CVP and PCWP BOTH reflect? | Vascular volume, vascular volume to venous tone relationship, & ability of ventricles to pump blood. |
What is normal JVD? | < 3 cm above sternal angle |
When do we use a CVP? | To assess circulating blood volume & assess right Ventricular function |
Possible routes of access for a CVP? | Jugular vein or subclavian vein, Femoral is rare! |
Which CVP insertion site has a more serious risk for a pneumo? | Subclavian |
Risks and Complications of a CVP? | Infection, bleeding, pain, air embolism, thrombus & pneumo |
What does the a wave represent on a CVP and atrial waveform? | Atrial contraction ( and it follows the P wave) |
What does the x descent represent on a CVP and atrial waveform? | Fall in right atrial pressure as the atria relax and the ventricles fill |
What does the c wave represent on a CVP and atrial waveform? | Closure of the AV valve (ventricular systole) |
What does the v wave represent on a CVP and atrial waveform? | The filling of the atrium DURING ventricular systole ( AV valves are closed) |
What does the down slope of the v wave represent on a CVP and atrial waveform? | Fall in atrial pressure when AV valve opens and fills the ventricle! |