Proper operation is not enough!?
When using AED (automated external defibrillator)
for the first time...

Preface of the research

We have started to see AED (Automated External Defibrillator) around many facilities such as train stations, airports, schools and hotels. AED is a medical device that attempts defibrillation by giving electronic shock to the heart, which suddenly vibrates thinly and is unable to get the blood pumping (ventricular fibrillation), so it will start pumping again.

In the past, only doctors or qualified person of same kind are able to handle AED, but from July 2004, average citizen who are not co-medical are being able to use it on an emergency basis.

This means, those who have never used AED before may encounter a situation where they have to use it. Will the first-timer be able to use AED properly in an emergency basis?

This time, we would like to look into the users world, about AED that involves human lives.

How many people have actually used AED before?
(from questionnaire survey)

At first, we have asked our registered respondents to answer to our questionnaire about AED. Total of 89 respondents (49 females and 40 males) from teenagers to those who are in their 70's have responded to our questions. Since the number of respondents has been far more than what we have expected, we can assume that many people are interested in the AED.

Followings are the 6 questions:

• Q1) Have you seen AED be placed?
• Q2) Do you know that average citizen can use AED without doing a course?
• Q3) How much do you know about AED?
• Q4) Have you used AED before(including the course)?
• Q5) Experience in giving artificial respiration (including the course) and the number of times.
• Q6) Experience in giving cardiac massage (including the course)and the number of times.

For Q1 and Q2, roughly 80% of entire respondents have answered that they have either seen or knew about it. For Q3, there are 66% who have answered, "know the name, as well as what it is for, but don't know how to operate it". 30% know hot to operate it. 82% of entire participants are those who have never used it. From this result, the actual situation is that AED is a big name, but there are only 20 % of those who have actually used it.

Those who have experienced in active resuscitation (both in artificial respiration and cardiac massage) of Q5 and Q6 have stayed to about half the respondents. For the number of times, half of those who have experienced only experience once, and roughly 40% of them have experienced 2 to 3 times. From the result we have found that the experience in active resuscitation is not very high.

Now, you may be wondering why we talk about cardiac massage, when the topic of this article is AED. Fact is this cardiac massage is the key point in using the AED.

Your friend has passed out!
(implementation of usability test)

Secondly, we have asked some of the respondents to participate as participants for a usability test of AED, which we conduct with the following manner.

(1) Task content

You were jogging with your friend at the park near the train station.

15 minutes after you started running, your friend suddenly started acting strange, and then passed out on a street. You tapped his shoulder and called his name loudly over and over again, but there was no response. You put your ear close to his nose or mouth, but he seemed not breathing.

Somebody who happened to be passing by called for an ambulance, and brought AED from the nearest train station for you. What ambulance attendant told was to use AED immediately if available.

Please use AED to give treatment to your friend. The task ends when the ambulance arrives.

(2) Participants' profile

All participants (11 people) have never used AED before. 4 out of 11 people have experienced in giving cardiac massage (3 persons have done it once, and 1 person have done it 6 times), while the other 7 participants have never experienced.

(3) AED

At the test, we use training equipment with audio assist function and a mannequin. With AED training equipment, you will not feel any electric shock by pressing the shock button, but rest of the function are made as same as the real equipment.

(4) The condition of the sick person

AED will automatically diagnosis electrocardiogram of the sick person, and determine whether giving electric shock is necessary of not. For this test, we have set to give electric shock twice.

(5) Performance environment

• There are a moderator (gives task instruction, and observe the participants' behavior, as well as gives advice when the participant gets lost) and a participant in the room where the task is performed.
• Participant will perform the task assuming one is alone. Basically, the operation method will not be taught.

(6) Operation procedure of AED

1.Turn the AED on -> 2.Expose to the waist of the sick person. -> 3.Paste electrode pad on his chest. -> (AED automatic diagnosis) -> 4.Press shock button -> 5.A person who gives aid to the sick person will press on the sternum(cardiac massage) -> (AED automatic diagnosis) -> If it is necessary to give shock, go to procedure 4., but if not necessary, go to procedure 5. -> 6.Have the rescue crew to take over with the remain condition wearing the electrode pads(Finish).

* We are skipping artificial respiration.

How long does it take to give electric shock after receiving the AED?
(From test result)

When the heart goes into ventricular fibrillation, it is said that the chance of survival will drop off for about 10% in every minute elapses (quote from Japan Heart Foundation http://www.jhf.or.jp/aed/qq.html).

This means, if the time upon giving the electric shock is as short as possible, there is more chance to survive. To get the rough idea, within 3 minutes will be desirable. The average time required for 11 participants has been 2 minutes and 47 seconds. 7 out of 11 participants have been able to do within 3 minutes (64%), whereas 4 out of 11 participants (36%) have taken more than 3 minutes. Only C has taken long time because of receiving the advice from the moderator along the way.

The fastest person takes 1 minute and 40 second, while the slowest person takes more than 3 minutes, which shows variation in time required depends on person.

What kind of issues has occurred when use AED for the first time?
(From test result)

Here are some issues points from the usability test results.

(1) Almost drop AED when taking it out from the carrying case. ...participant K

[Correct procedure] Place the case near the sick person's head, and take AED out.

Participant K: "Because I tried to take it out from the case in standing position, I almost dropped the AED."

When it is an emergency, immediate attention will be requited, so the person who gives aid wishes to do so as soon as possible. AED is placed in the case that is portable, but the inside is invisible. Therefore, it is unpredictable how it is placed until the zipper is unzipped. If the zipper unzips as one rushes to the sick person, drops the equipment and breaks it, it will be no point of giving a hand. The basic is to use it by setting AED near the sick person's head, but there is no such advisory on the case. It is desirable for the user to know what one should do before taking AED out of the case.

(2) Tend to think it is not necessary to take his cloth's off.
...Participants B, C, D, and F

[Correct procedure] Take his top off by looking at the illustration on the manual or electrode pads.

[Advisory] If the person remains wearing the top, electric shock will not run effectively.

Participant C: "I thought I could give the person a shock without taking his top off. The illustration on the pads did not give me any perception that I needed to take his top off."

Participant D: "I only unzipped but not taking his top off. Because I thought his temperature would drop rapidly, I did not want to take his cloth off"

Participant F: "I only unzipped but not take all his cloth off. This was because I felt sorry for him. If the person was a unknown woman, I would be confused. Since stun gun could give shock over the cloth, I thought I can paste the pads on the cloth."

Taking the top off is a basic premise upon using AED. Since it will be a preliminary work before using AED, if one trips at the start, it will give a big damage to the sick person. Before concerning the person's privacy, it is necessary to give instruction to certainly take the top off.

(3) Not know the correct way to paste the pads. ...Participant B, C and K

[Correct procedure] Audio assist will guide, "Please attach the pads", so by looking at the illustration on the manual or electrode pads, peel the electrode pads off from the label, and paste them on upper left of the chest(below collar bone) and left rib.

[Advisory] After the electrode pads are pasted, do not touch the body while diagnosing electrocardiogram or charging.

Participant B: "I thought I only needed to tear along perforation of the label and paste them. Did not know whether I could peel off the pads from the label."

Participant C: "I did not peel off them from the label. I won't understand if it is not written that I need to paste directly to the skin."

Participant K: "I touched the pads during the analysis of electrocardiogram because I was anxious about the direction of those pads. I got nervous thinking that I was not pasting them as in the illustration."

Since the electrode pads are unexpectedly large (about 10cm X 15cm), it seems that participants have had difficulty in fining the difference between electrode pads and the labels. Also, since many electrode pads are come from different manufacturers than AED itself, it is likely that users will not understand only by looking at the explanation on the pads. It is necessary to give instruction on where to paste the pads specifically by the audio assist.

Also like participant K, users will be nervous about whether the pads are pasted correctly. They worry thinking what if the person does not recovered just because the pads are not pasted correctly. It is must to be able to check whether they are pasted correctly. Eliminate the concern of users who are trying to give aid will connect to the rescue.

(4) Do not press on the sternum(cardiac massage) after giving the electric shock
...Participant A, C and J

[Correct procedure] Follow the audio assist("Immediately press on the sternum and give artificial respiration"), and start pressing on the sternum immediately.

[Advisory] When the heart fibrillate, it will not be able to pump the blood. Instead, a person giving aid will press on the sternum. AED is an equipment that pure and simply triggers defibrillation, and not to pump the blood.

Participant A: "I thought AED would give shock many times until he recovered. I thought AED would do everything. I did not assume I needed to do things by myself."

Participant C: "I turned off and on the AED again because I thought the heart would pump if I gave shock again. I would understand if it was resuscitative effort, but because I did not know what press on the sternum meant, I did not do it."

Participant J: "I thought AED would do everything, I did not do neither press on the sternum nor give artificial respiration. I did not know how to do it."

In case of using AED for the first time, we understand that there are people who misunderstand and think that AED will do all the treatment. Also, it seems there are people who thinks giving electric shock repeatedly will do. As long as the heart is fibrillating, the person will not recovered if not continue pressing on the sternum. The person will not survive just by giving electric shock.

We understand now that although the user can operate AED correctly, if one does not press on the sternum immediately, there will be a risk that person will die.

Expecting that AED will do all the treatment is a big misunderstanding. It is necessary to have the users to understand that using AED is a set with the resuscitative effort.

It may help if the audio assist clearly instructs, "The heart is not pumping well. We ask you to please press on the sternum instead."

(5) Do the wrong way of pressing on the sternum ...participant A, B, D, E, I and K

[Correct procedure] Follow the audio assist, and press on the sternum. (There is neither specific instruction nor explanation on how to press on the sternum). Place two hands on the middle between both nipples, and press as the chest will go down of 4-5cm, with speed of 100 times per minute. Continue this for 2 minutes, and wait and see.

[Advisory] If continue pressing on the sternum in wrong way, or stop in the middle, an effective blood circulation will not happen, and may give damage to the brain, or lead to death.

Participant A and B: "I did it by reaching back in my memory of the lesson at the driving school."

Participant A: "I was unsure whether what I was doing was right or wrong, and also how long I had to continue doing it."

Participant B: "Since there is no instruction on how to press on the sternum, I did not know how to do it."

Participant D and I: "I did it by recalling my memory of the TV program I watched"

Participant I: "I intended to press on the sternum for artificial respiration. I did not know the correct way of pressing on the sternum. I wanted it to tell me whether I was doing right of wrong (pressing too hard or slow down)."

Participant K: "Because I got qualification of emergency medical technician of the city, I did it the way I did back then by recalling my memory. I wanted to know the explanation of the place to put the hands and the pace."

This is the issue we have observed the most during the test. Those who have less or no experience in pressing on the sternum have done it by recalling their memories of the TV program they have watched or the workshop they have taken before. However, those memories are vague or they have done it in wrong way.

Since there is no detailed explanation about how to press on the sternum on the AED we have used at the test, we have found that many participants get confused. (Reference: There are AEDs that give audio assist of detailed explanation.)

As it comes cleared in the questionnaire, nearly half of the people have never experienced active resuscitation, and although they are experienced, nearly half have experienced once, the equipment should be made as even those people need to be able to use it without any confusion.

Their impression on using AED for the first time.

Participant A: "I've heard from TV that AED is something anybody can use, but it is unexpectedly quite difficult to understand."

Participant B: "The operation itself of AED was not so difficult, but I was worried whether my way of pressing on the sternum was correct or not."

Participant D: "At first, I thought it was something to carry the sick person to where AED was placed. Since AED is an electric appliance, I thought it was plugged in. I want the audio assist to give instruction on how to press on the sternum."

Participant E: "Instead of how to use AED, I wanted to know whether my way of giving heart massage is correct or not."

Participant F: "I want an announce that calm person who uses the AED."

Participant H: "I have been thinking that it continually gives electric shock, but it actually isn't. It was easy to use than I was expected."

Participant K: "I thought AED would cover everything till the ambulance arrived. I did not know that I had to do the resuscitation."

Overall, there are many comments that AED is not so difficult to operate. The fact that one needs to conduct rescue, and being confused not knowing how to press on sternum, are something they have felt hard.

Impression toward the research

Although there are many types of AED, but the basic operation procedure (paste electrode pads -> (diagnose) -> Press shock button -> Press on the sternum and give artificial respiration) is same. As what participants have commented, as far as the operation goes, it is relatively easy. However, we have found out that whether one knows how to do the resuscitation or not is, in fact, very important in using the AED.

In different AEDs, we hear that there are those with and without audio assist. Although the difference in spec by different manufacturer is inevitable, if the equipment is going to be generalized from now, then the AED should be an equipment which even one who does not know how to press on the sternum can use it with confident.

For how to press on the sternum, one can be instructed the correct procedure when call emergency. However, it is an open question whether one can think to call and ask in the tense situation. Also, one may has to use AED in a no service place.

Participant H, who has experienced resuscitation for over 6 times, has conducted correctly. Nonetheless, it is understood that if users receive workshop of AED and resuscitation on the routine basis, then they will be able to handle it.

The workshops on AED and how to resuscitation, is organized by fire departments and Red Cross in different regions, and anybody can participate. Also, there are many websites that give clear explanation. As we see from the test result, it is understood that to take the workshop just in case is very important.

Why don’t you take this opportunity and experience it?

Created in 2009.08.31