1. Witnessed VF: Treated With an AED and CPR
Case 2
Witnessed VF: Treated With an AED and CPR
© 2001 American Heart Association
ACLS providers should be aware that each person must display the skills of 1-rescuer adult CPR plus use of an AED.
Successful completion of the Heartsaver AED Skills Checklist is required for successful completion of the ACLS Provider Course.
This case is not the time to learn AED operation or CPR. Those skills are acquired before the course, during the skills station review, or during remediation at the end of the course.
This case should be quick and easy. The major purpose of this case is to allow providers to consider a very realistic and increasingly common situation: being asked to assist a passenger who has collapsed during a transoceanic commercial airliner flight. 1

2. Case Scenario You’re on a flight to Hawaii
A flight attendant asks “Would a healthcare provider please come to the middle galley?”
At middle galley: 2 flight attendants are doing chest compressions and pocket-mask ventilations on a 55-year-old man
Lying to one side: an opened, partially deployed AED
What would you do next?
This scenario starts case management immediately without an overview of general cardiac arrest management.
Direct the providers to start exactly where the scenario ends.
Encourage providers to speak out with the specific phrases they plan to use if they are ever faced with this scenario:
“Do you know how to use an AED? Get out of my way and let me show you!”
“I sure hope you know how to use that thing because I don’t have a clue.”
Best: “Hello, my name is Dr. Defib. How can I help you? I know ACLS, CPR, and how to use an AED.”
Keep repeating the question “What would you do next?” to each member of the group. Keep asking until the group has successfully managed this patient up to transfer to ground emergency providers.
Have the ACLS providers perform CPR for 30 seconds, and then ask them to demonstrate or describe the use of an AED.
Many ACLS providers still question the need to learn to use an AED. This case scenario goes a long way toward answering that question. The growth of PAD is exponential now. A highly sophisticated critical care expert might face this exact situation at any time.

3. Learning Objectives Provider—in role of lone rescuer—able to describe
Management of VF collapse with AED, gloves, mask
1st action steps: start = collapse of victim
CPR sequence: CPR, phone 911, get AED
AED sequence: AED at victim’s side to no shock indicated
2nd rescuer arrives: how to include?
Special AED situations: how to manage
Children <8 years
Wet environment
Implanted pacemaker/defibrillator
Medication patches
This case rehearses a “worst case” scenario: the lone rescuer without others to help and provide some component of CPR or AED use.
Set the scene as one of self-reliance.
Emphasize that the lone ACLS provider has the ability, using early CPR and early defibrillation, to achieve success rates in resuscitation equivalent to those of a full advanced life support team arriving late.

4. Background: VF and Defibrillation
VF: rhythm causing “all” sudden cardiac arrest
VF: useless quivering of heart  no blood flow
VF treatment: only one therapy works  defibrillation
Defibrillation success: chances drop every minute
The rationale for early defibrillation should be familiar to all ACLS providers and instructors.
VF: the rhythm causing “all” sudden cardiac arrest. Although most sudden cardiac arrests are due to VF, a small percentage (<15%) are not, and these arrests are seldom “sudden.” Some people will arrest from a bradycardia-to-asystole sequence, but this occurs more gradually over the course of an hour or so.
We often forget how unique VF and defibrillation are in all of medicine: a sudden, fatal condition that invariably results in death unless treated with one, and only one, therapy—defibrillation. This therapy is both necessary (no other treatment works) and sufficient (defibrillation is all that is needed).
The other point to make here is how defibrillation success is remarkably and predictably time-dependent. Time is discussed further in the next slide.

5. Background: Defibrillation and Time
Approximately 50% survival after 5 minutes
Survival reduced by 7% to 10% per minute (if no CPR)
Rapid defibrillation is key
CPR prolongs VF, slows deterioration
Although the time-dependency of VF is virtually a cliché, by 2001 all ACLS providers must understand how remarkably time-dependent VF is:
Without treatment VF steadily decays toward asystole with each minute.
With CPR the rate of this decay is slower.
With CPR more people are in VF when the defibrillator arrives.
With CPR more people respond to a shock with a post-shock perfusing rhythm.
Explain the familiar graph above as follows:
It is based on large databases of out-of-hospital cardiac arrest.
Average ages are 67 for women and 63 for men.
“Baseline” of time zero comes from people who arrest after the arrival of EMS personnel; therefore a time to first shock of <1 minute does occur. These patients, by definition, are usually markedly ill; otherwise they would not have called EMS providers. If the victim is defibrillated within the first minute of VF onset, the probability of survival ranges from 70% to 90% (the 90% figure has been achieved in casinos, airports, and airplanes).
“Survival” is defined as restoration of pulse in the field, admission to hospital, and discharge from hospital to home with little if any residual deficit.
The next slide provides an excellent demonstration of the value of CPR.
Minutes: collapse to 1st shock

6. Probability of Survival Is Related to 2 Intervals: (1) Collapse to Defibrillation and (2) Collapse to CPR
Collapse to start of CPR: 1, 5, 10, 15 (min)
Probability of survival to hospital discharge
This important graph is derived from combining data from 2 large EMS systems1,2 (reference citations are on slide 7).
The graph shows how important the combination of early CPR and early defibrillation is to survival to hospital discharge. No data is available on the success of defibrillation without CPR except at the start of each CPR curve: if CPR starts 10 minutes after the arrest and defibrillation is performed at that time, the probability of survival is approximately 10% to 12%. If CPR had been started at 5 minutes or 1 minute after arrest, the same shock at 10 minutes would have been much better: 18% probability of survival if CPR had started 5 minutes earlier, 23% if CPR had started immediately (<1 minute).
As noted elsewhere in this case, CPR has 2 positive effects: it makes VF last longer and when the victim is defibrillated it makes the post-shock rhythm more likely to be perfusing.
Some providers will note puzzling conclusions from such graphs. For example, if the curve for CPR starts at 15 minutes and defibrillation is performed at 20 minutes, the graph suggests a survival rate of 5% or greater. Five percent seems impossibly high for such an ominous clinical scenario.
The explanation has to do with applying mathematical models, multiple regression statistics, and logistic regression statistics to large data sets. Mathematical “smoothing” occurs at the extremes and can result in some curious implications.
The point is less the specific data derived from such graphs and more the overall pattern: early CPR and early defibrillation work together to produce the best outcomes.
Collapse to defibrillation interval (min)

7. Probability of Survival Is Related to 2 Intervals: (1) Collapse to Defibrillation and (2) Collapse to CPR (cont’d)
Graph displays probability of survival to hospital discharge in relation to interval to defibrillation
For 4 given intervals: collapse to start of CPR (1, 5, 10, 15 min)
Example:
If time to defibrillation = 10 min and time to CPR = 5 min, probability of survival = 18%
Data from
King County, WA (n=1667 witnessed VF arrests)1
Additional cases (n=205) from Tucson, AZ2
This slide is a continuation of the previous slide and explains more of the graph.
The data sources were EMS systems in King County, Washington (approximately 90% of the cases), and Tucson, Arizona (the remaining 10%). Both of these EMS systems have reputations as successful EMS programs.
Eisenberg et al analyzed the data using a multiple regression technique. Valenzuela et al used logistic regression, which resulted in a different and more communicative display. The interested reader is referred to the Valenzuela article, which is available online at
1Eisenberg et al. Ann Emerg Med. 1993;22:
2Valenzuela et al. Circulation. 1997;96:

8. Background: Know Your AED1 2 3
Instructors should ask learners to point out or to note the following:
The major components of an AED:
Pads to skin (point 1)
Pads to cables (point 2)
Cables to AED (point 3). Point out the circuit that must be completed: skin to pads, pads to cables, cables to AED box; when troubleshooting any problems, make sure the circuit is completed.
Three different types of event documentation module (solid-state memory module, standard magnetic tape microcassette, PCMCIA memory card [“flash” memory cards])
Event documentation modules record primarily 2 things: (1) voices and sounds at the scene and (2) a complex analysis of the cardiac rhythm (includes initial rhythm, interpretation by the AED Treatment Algorithm, shocks indicated, shocks delivered, response to shocks, last rhythms recorded).
The proper locations for pad placement:
Right sternal border, below the right clavicle
Left side of chest, one edge touching the anterior axillary line, top edge touching the nipple
The “4 universal control steps” of AED operation:
Power ON
Attach
Analyze
Shock

9. Operation of AEDs: 4 Universal Control Steps
1. POWER ON the AED
2. ATTACH pads
3. ANALYZE rhythm
4. SHOCK (if advised)
The universal control steps are called universal because they are used to operate every AED. Because of the concept of “user-critical steps,” more of these universal steps are done automatically and not always by the operator. Ask providers to demonstrate use of the specific AED that they will use in their work setting.
User-critical steps are any operational steps that must be performed by the operator; otherwise the device will fail. All AEDs require similar user-critical steps:
Attach the defibrillator pads to the patient
Attach the pads to the AED cables
Attach the AED cables to the AED
Power on the AED
Analyze the patient signal for VF
Charge the AED if VF is present
Press the shock button to deliver the shock
Notice how each step is critical. If any one step is omitted or done incorrectly, the person in VF will not be defibrillated. Any error here would mean the loss of a chance to save a person’s life.
Some brands of AEDs perform these steps. The more an AED performs the user-critical steps, the lower the chance of error. For example, some AED models power up automatically when the AED lid is opened; in some the cables are preattached to the AED and the adhesive defibrillator pads. Some perform constant background analysis and will automatically “precharge” if VF is detected. One model has reduced the number of actions required of the operator to just 3: open the lid, attach the pads to the patient, and press the shock button. ON

10. Primary ABCD Survey Focus: Basic CPR and Defibrillation
Check responsiveness
Activate emergency response system
Call for defibrillator
A = Airway: open the airway
B = Breathing: check breathing, provide positive-pressure ventilations
C = Circulation: check circulation, give chest compressions
D = Defibrillation: assess for and shock VF/pulseless VT
The first steps in all emergency treatment are quickly assess responsiveness, activate the EMS system, assess the ABCs, and if indicated start CPR and hunt for VF with the AED.
The Primary ABCD Survey of the ACLS Approach is an effective way to remember these steps. Some people in apparent cardiac arrest will respond to the initial actions: A, opening the airway; B, performing ventilations; and C, performing chest compressions. These steps can also identify victims of an obstructed airway, which must be cleared.
For patients without a pulse, the Primary ABCD Survey makes no mention of IV access. This is intentional. Although medications provide a clinical benefit in cardiac resuscitation, medications remain a distant second in the Primary ABCD Survey.

11. AED Treatment Algorithm (Start)
Unresponsive—911—AED:
Check if unresponsive
Call 911 (or emergency response number)
Get AED
Identify and respond to special situations
Unresponsive
Start the ABCDs:
Airway: open airway
Breathing: check breathing (look, listen, and feel)
This AED algorithm is found in the 2000 ECC Handbook, page 5.
The algorithm is another memory aid for ACLS providers to have immediately available.
The algorithm helps instructors answer some of the more detailed questions that might be thrown at them, such as the subset of patients who may have preserved breathing or preserved circulation despite unconsciousness or unresponsiveness.
Yes, Breathing
Not Breathing
If breathing is adequate: place in a recovery position
If breathing is inadequate: start rescue breathing (1 breath every 5 seconds)
Monitor signs of circulation* (every 30 to 60 seconds)
Provide 2 slow breaths (2 seconds per breath)
Circulation: check for signs*

12. AED Treatment Algorithm (End)
Yes, Circulation
No Circulation
Start rescue breathing (1 breath every 5 seconds)
Monitor signs of circulation* (every 30 to 60 seconds)
Perform CPR (until AED arrives and is ready to attach):
Start chest compressions (100/min)
Combine compressions and ventilations
Ratio of 15 compressions to 2 breaths
Attempt Defibrillation (AED on scene):
POWER ON the AED first!
ATTACH AED electrode pads (stop chest compressions for pad placement)
ANALYZE (“Clear!”)
SHOCK (“Clear!”) up to 3 times if advised
Memory aid for “no shock indicated”:
Check for signs of circulation*
If signs of circulation* present: check breathing
If inadequate breathing: start rescue breathing (1 breath every 5 seconds)
If adequate breathing: place in recovery position If no signs of circulation,* analyze rhythm: repeat “shock indicated” or “no shock indicated” sequences
*Note: Signs of circulation: lay rescuers
check for normal breathing, coughing, or movement
(typically assessed after 2 rescue breaths delivered to
the unresponsive, nonbreathing victim).
Use this algorithm to walk providers through the steps of AED use integrated with CPR.
The memory aid for “no shock indicated” states what the provider should do when he or she hears that message from the AED. But it does not go into what that message can mean. Ask that question and review quickly with the providers:
VF is absent; the rhythm, if any, is not VF.
The person, if analyzed after a shock, has converted to normal sinus rhythm and may have a pulse (a “Save!”).
The person, if analyzed after a shock, has been defibrillated out of VF and into asystole (most likely).
If heard at the first analysis, the message “no shock indicated” probably means the person is not in VF and probably will not go into VF.
Note that a defibrillation attempt “stuns” the heart into total depolarization. The providers must give the heart some time to recover and display the true effects of the shock. This requires at least 1 minute, a time during which the rhythm may show a variety of responses (see next slide).
After 3 shocks or after any “no shock indicated”:
Check for signs of circulation*
If no signs of circulation:* perform CPR for 1 minute
Check for signs of circulation.* If absent:
Press ANALYZE
Attempt to defibrillate
Repeat up to 3 times

13. AED Safety With every analysis and shock: no one touches patient!
Verbal: warning to bystanders—
“I’m clear”
“You’re clear”
“Everybody’s clear”
Visual: check “all clear”
Physical: add hand gestures
Only then press to shock
Emphasize the importance of safety and clearing the victim. These steps require both oral communication and visual inspection of the victim.
To ensure safe defibrillation the operator must always announce when he or she is about to deliver a defibrillatory shock. The person should state firmly and in a loud voice a “warning chant” before each shock, for example:
“I am going to shock on three. One, I am clear.” (The operator checks and makes sure he or she has no contact with the patient, the stretcher, or other equipment.)
“Two, you are clear.” (Note in the slide the use of physical hand gestures, as if “pushing” the other responder away from the danger of a shock.) The operator checks all personnel touching the patient, including providers who are doing chest compressions, starting IVs, inserting catheters, or performing ventilation and airway maintenance. All providers should step back slightly and remove their hands from the patient and any device or object touching the patient.
“Three, everybody is clear.” (The operator makes a visual check to ensure that no one else has contact with the patient or stretcher.)
The person operating the defibrillator need not use these exact words but must warn others that he or she is about to administer defibrillation shocks and that everyone needs to stand clear.

14. Special Situations Age: victim <8 years old?
Water: victim lying in water?
Pacemaker or implanted defibrillator: treatment interference?
Transdermal medication patches: blocking pad placement?
Children: Default energy settings on AEDs are too high (defined as >10 J/kg) for children less than 8 years old.
Recommended action: If the victim is younger than 8, do not use an AED (unless product advances yield more suitable devices). 
Water: Realistically the chances of a significant shock to a rescuer are negligible, even if the victim is lying on a wet surface and the rescuer is standing on the same surface.
Recommended actions: Remove the victim from contact with water if it can be done easily without delaying defibrillation more than 1 minute.  Drag the victim gently by the arms or legs or use a blanket or towel to drag him.  Dry the victim’s chest and back quickly before attaching the AED.
Implanted pacemakers or defibrillators: Placing an AED electrode pad directly over an implanted medical device may reduce the effectiveness of defibrillation.
Recommended actions: Place an AED electrode pad at least 1 inch to the side of any implanted device.
Transdermal medications: Placing an AED electrode pad on top of a transdermal medication patch may decrease the delivered energy of a shock and make it less effective.
Recommended action: Remove the medication patch; wipe the area clean before attaching the AED or monitor electrodes.

15. What’s New in the ECC Guidelines 2000?
(Walcott et al. Circulation. 1998;98: )
A= monophasic (damped sinusoidal [Edmark])
B= biphasic (quasisinusoidal [Gurvich])
C= biphasic (truncated exponential)
Biphasic waveform defibrillators: great promise
Different waveforms: acceptable
Most common: monophasic (DpSn) (A)
Seldom used: monophasic (TrEx)
Multiple new brands: biphasic (B and C)
All are currently acceptable
New waveforms: “OK” if supported by
human clinical trials
Fair
Best
In the 1990s there were 2 major developments in the technology of defibrillation:
First, confirmation of AEDs as valid and effective therapy with numerous advantages over conventional defibrillators and as key to opening the door of true early defibrillation through public access defibrillation programs
Second, confirmation of biphasic waveform defibrillation as a major advance in defibrillation technology
Although not clearly understood, biphasic shocks appear to achieve a higher level of defibrillation on first shock and with fewer than 4 shocks.
Biphasic shocks defibrillate better and at a lower delivered energy. For example, first shock success at 200 J biphasic ranges as high as 95% to 98%; first shock success at 200 J monophasic averages less than 70%.
The ECC Guidelines 2000 experts concluded that valid and acceptable evidence supports biphasic waveform defibrillation as equivalent to monophasic waveform defibrillation. All claims related to defibrillation success or failure must be supported by published scientific data. At this time the AHA position on biphasic waveform defibrillation is that such waveforms are acceptable if supported by clinical evidence.
(continued in notes on next slide)
Good

16. What’s New in the ECC Guidelines 2000?
Different waveforms: success at different shock energies:
Escalating shock energy (200 J; 200 J-300 J; 360 J) = OK
Nonescalating shock energy (200 J-200 J-200 J) = OK
Key: scientific data must support
equivalent effectiveness
The greater success of biphasic waveforms has been used to lower the shock energy level to the 130- to 170-J range without sacrificing the superior rate of first-shock success.
Some companies have capitalized on these advantages by limiting the energy level of biphasic shocks to only one lower level. By eliminating higher energy choices these devices eliminate size, weight, and expense.
But has something been lost by not being able to escalate the energy level through the familiar escalating values of 200 J, 200 to 300 J, up to 360 J? In theory there should be some patients in refractory, shock-resistant VF who will be defibrillated only if the energy level of the shocks can be greatly increased. Although experts and manufacturing representatives have debated this question interminably, we currently lack definitive human data to document significant deficiencies in nonescalating biphasic waveform defibrillators.
The ECC Guidelines 2000 experts reviewed data available as of early 2000 and concluded that equivalence appeared to exist between nonescalating biphasic shocks and escalating monophasic shocks.
Note: To keep things in perspective in the debates over waveforms, point out that the clinical difference between best and worst waveforms or escalating and fixed energy levels is equal to about 2 minutes’ difference between time of collapse and time of first shock.

17. What’s New in the ECC Guidelines 2000?
New Class IIa Recommendations
Goal: interval from collapse to 1st shock <3 min in >90% of arrests (for in-hospital and ambulatory care areas)
AEDs = key to make this possible
Conclusion: all ACLS providers should be trained in CPR and AED defibrillation
The ECC Guidelines 2000 experts recognize that the “In-Hospital Chain of Survival” can pose as many barriers to early defibrillation as the “Out-of-Hospital Chain of Survival.”
The problem in both settings has been how to best achieve early defibrillation. The centralized response concept of bringing all advanced life support tools to the scene in a frantically pushed-and-pulled “code 911 cart” cannot possibly achieve hospital-wide or outpatient clinic-wide early defibrillation in many institutions.
Lacking definitive evidence, the ECC Guidelines 2000 experts selected and endorsed the concept of having hospitals achieve a high percentage of all in-hospital cardiac arrest victims being evaluated, treated, and defibrillated for VF within a short interval from collapse to arrest. Without high-level evidence, the ECC Guidelines 2000 recommend this approach. One objective example has been the achievement of having 90% or more of in-hospital cardiac arrest victims receive VF evaluation and treatment in less than 5 minutes. (These specifics are not an official AHA recommendation but rather an example of specific performance goals that can be set.)
The AED, placed strategically within a hospital and associated outpatient clinics, could facilitate much earlier defibrillation if a much larger number and range of healthcare personnel were authorized to operate AEDs.