Hemodynamic Monitoring Flashcards
What is preload & what is afterload?
KNOW THIS!!! … in red
Preload: maximum stretch of the ventricles once ventricular filling is complete at the END of Diastole (end diastolic volume)
Afterload: resistance the ventricles have to pump against to circulate blood (pump it throughout the body)
What is the equation for cardiac output?
KNOW THIS!!!
HR x Stroke Volume = Cardiac Output
What factors contribute to stroke volume?
KNOW THIS!!!
- preload
- contractility
- afterload
What is stroke volume?
KNOW THIS!!!
amount of blood pumped by a ventricle with each beat
How does tachycardia impact cardiac output & coronary filling?
KNOW THIS!!! … in red
DECREASED (↓) cardiac output & coronary artery filling due to…
- fast ventricular rate
- not enough time for the ventricles to properly fill
What is the resistance the heart has to pump against?
KNOW THIS!!! … in red
IN RED
Afterload
1.) Explain what each of the letters in a Pacemaker (NBG) code stands for.
2.) Explain the 4 types of ventricular codes:
- DDD
- VVI
- DOO
- VOO
KNOW THIS!!! … in red
IN RED
1.) Each of the 3 letters in the code
* 1 = Paced chamber
* 2 = Sensed chamber
* 3 = Response to sensed event
2.) What each code stands for
* DDD = dual paced (both atrium & ventricles), dual sensed (both atrium & ventricles), dual response
- VVI = ventricles are paced (Ventricle paced, Ventricle sensed, Inhibit (inhibit pacer from firing)
- DOO = Dual Off Off (Dual paced, Off sensing, Off response)
- VOO = Ventricular Off Off (Ventricular paced, Off sensing, Off response)
Explain the following Pacemaker codes:
- DDD
- VVI
- VOO / DOO
KNOW THIS!!! … in red
IN RED
DDD pacing is the most physiologic (enhances atrial contribution to ventricular filling)
VVI is designed to pace ventricles
- DOO & VOO are asynchronous pacing modes that are only used in certain circumstances
How is preload measured?
KNOW WHAT IS IN RED!!!
IN RED
- Lung sounds – are they wet?
- I & Os
- S3 Heart Sound heard when patient has extra fluids in the body!!!!!
- BNP
- Weight (gaining weight quickly)
- Chest X-ray
- Oxygen saturation
- Subjective findings (dyspnea)
- Objective findings (accessory muscle use)
What can be done to increase preload?
maximum stretch of the ventricles
- Fluids / add volume (hypervolemia)
- Vasoconstriction (increases BP & increases ventricular filling)
How can we decrease preload?
- vasodilate (decrease BP & ventricular filling)
- Diuretics (decreases fluid volume)
What is afterload & what factors can affect it?
Afterload = resistance heart has to pump against to get blood flowing to the rest of the body
FACTORS:
* age (stiffness = less contraction)
* HTN
* Constriction of arteries
What are signs & symptoms can increased afterload?
KNOW THIS!!! … in red
IN RED
- Crackles in the lungs (blood backs up
- Dyspnea
- Mental Status Changes (due to low O2)
What is the range for pacemaker rate? What is the output in terms of pacemaker settings?
**Rate = ** 60 - 80 BPM
- Output = spike before each beat
What is involved in a modified allen’s test? What is the goal?
GOAL = check for collateral circulation in the hand
Procedure
1.) apply pressure to radial & ulnar arteries until the skin on the patient’s palm is blanched
2.) ULNAR artery is released while keeping pressure on radial artery
3.) Releasing of ULNAR ARTERY (while keeping radial artery compressed) should result in flushing of hand within 5-15 seconds
Collateral meaning not the main blood supply to the hand …main blood supply to arm / hand = subclavian
