Hemodynamics Flashcards
2 things Validity must have
Consistency
Integrity (accurate data) - nurse’s responsibility
*Equation for pressure
Pressure = flow X resistance
*(Increased flow &/or resistance = increased pressure)
*(increased volume = increased pressure)
Common types of hemodynamic monitoring
- Arterial pressure monitoring (Art line)
- Pulmonary artery pressure monitoring (PA catheter; Swan Ganz)
- Right atrial pressure monitoring (RAP or CVP: central venous pressure)
What does the transducer do?
Converts physiological events into electrical signals
What does the amplifier do?
Picks up electrical signal and transmits to display through cable
What should the bag be pressurized at for hemodynamic monitoring?
300 mm Hg to keep line open
*What is the nurse responsible for when taking care of a hemodynamic monitoring device?
Level
Balance
Calibration
What is the level called? where is it?
Phlebostatic axis (4th ICS MAL) - where the transducer is leveled (transducer should be on IV pole, kept at this level)
What is the balance?
Zero reference (negates atmosphere pressure) - button on machine to take away atmosphere pressure
Why is calibration done?
How is it done?
When is it done?
For numerical accuracy
done with a *square wave test:
- 1x per shift
- during position changes
- after blood draw
Indications for intraarterial monitoring (minute to minute BP monitoring)
- Continuous BP monitoring (severe hyper/hypotension)
- Blood drawing
- Vasopressor infusions
Sites for intraarterial monitoring:
Radial = preferred
Brachial
Femoral (no longer recommended)
Nursing consideration for radial intraarterial monitoring
Perform Allen test for circulation: to make sure ulnar artery is open & functional incase radial is damaged from this
**Nursing responsibilities for Intraarterial Monitoring
- Monitor waveform
- Compare values with BP cuff (A-line should be more accurate)
- Check connections in system
- Check site and circulation to extremities (q2hr)
- Set alarms
- Hold pressure for at least 5 min when dc’d (femoral at least 20 min)
- Infection control
- Maintain patency of system
Infection control nursing considerations for intraarterial monitoring
- change dressing/bag/tubing per protocol
- document dates for insertion/dsg changes
- assess for s/s of infection q4hr
- limit disconnecting system/sterile caps (keep system closed as much as possible)
Nursing considerations to maintain patency of system for intraarterial monitoring
- flush after each use
- maintain pressure of 300 mm Hg
- ensure adequate amount of flush solution
How much blood should be drawn from A-line and discarded?
3-10 mL, depends on hospital policy
Possible complications for intraarterial monitoring
Air Embolus = major complication (keep connections tight to avoid)
Hemorrhage (keep connections tight to avoid)
Thrombosis
Infection
Another name for Right Atrial Pressure
CVP
What does right atrial pressure measure?
RV preload / RVEDP
What is preload?
Volume of blood in right ventricle just prior to systole
*What does preload affect?
*Stroke volume and cardiac output
Normal CVP
0-8
*Interpretation for if CVP is low:
1st think: *Hypovolemia
Tx: give fluids (prob IV, like saliene bolus)
If no improvement in output/CVP: *Vasodilation
Tx: vasopressor like: norepi (Levafed)
*Interpretation for if CVP is high
1st think: *hypervolemia
Tx: diuretics (furosemide)
If doesnt work think: *vasoconstriction (pt in shock)
Tx: vasodilator like nitroglycerin or nitropresside
OR *right CHF
OR *pulmonary hypertension
Function of pulmonary artery catheter (swan ganz)
*Reflects left heart pressures
Can also measure cardiac output
*Wedge pressure aka *PA pressure aka *PCWP
Nurse’s job during insertion of PA catheter
Monitor pressures in each chamber
Record values
Assess for complications (dysrhythmias/pneumo/hemothorax)
*Interpretation of increased PA pressures
1st think: *volume overload (CHF)
Tx: diuretics
2nd think: vasoconstriction
Tx: vasodilators
*Interpretation of decreased PA pressures
1st think: *volume depletion
Tx: correct IV fluids
2nd think: vasodilation
Tx: correct with vasoconstrictor
What does TEE stand for?
Transesophageal echo
What is an esophageal Doppler? What does it do?
Thin silicone probe placed in distal esophagus to evaluate descending aortic blood flow (LV function)
