Transcript Dosage of enalapril for congestive heart failure in USA

Friendly skies?
Richard L Page MD
Associate Professor of Internal Medicine
Director, Clinical Cardiac Electrophysiology
University of Texas Southwestern Medical Center
Dallas, TX
In-flight cardiac care
Qantas success story
Qantas installed portable semiautomatic external
defibrillator devices (AEDs) in 1991 on all its
international Boeing 747 and 767 aircraft and at major
Qantas airport terminals.
In the 65 months after these devices were installed, 46
incidents of cardiac arrest were treated, 27 in aircraft.
27 passengers went into cardiac arrest and were treated
with the AED on board the aircraft. 6 of the 27 went
into ventricular fibrillation (VF). The defibrillator worked
in 5 of the 6. Two of them survived, apparently saved
by the defibrillators.
19 cases of cardiac arrest were reported at the airports;
17 of those went into VF and defibrillation worked
on all 17.
In-flight cardiac care
American Airlines follows Qantas’s lead
By July 1997, AEDs were deployed on all
international flights and certain domestic overwater routes; main flight attendants or pursers
were trained to use the defibrillators in the
event of an in-flight medical emergency.
By the end of 1998, all 649 American’s jet
aircraft had defibrillators on board, and all
24,000 flight attendants had been trained to
use the AED.
FDA guidelines
AED indications
FDA-designated indications for AED placement
• full loss of consciousness
• an absence of breathing, or
• absence of pulse
Physicians present can request that an AED be
used as a monitor because the device has a
monitor screen. If the device is used as a monitor,
it can then be placed outside of the typical or more
strict indications.
American Airlines study
204 cases of AED use
In 69% of cases a physician was present.
In 42% of cases loss of consciousness was documented.
Rhythms associated with death were seen in 28 of the
204 patients
• 14 of the 28 had agonal rhythm
VF was documented in 14 of the 204 patients
• shock was administered in 13 patients
• relatives of 1 terminally ill patient refused treatment
In 2 cases where shock was administered, the EKG
recording was not available for analysis, but it is likely
that VF was present.
Of the 15 patients who received shock for VF, 6 (40%)
were discharged from hospital to lead full functional lives.
Richard L Page MD, presented at the 21st Annual Scientific Sessions of the North
American Society of Pacing and Electrophysiology (NASPE), Washington, DC
American Airlines study
AED effective and safe
A 40% resuscitation from VF compares favorably
with any EMS system.
In many cases, the device was placed on
passengers with fatal rhythms, and often without
full loss of consciousness; but in no case did the
AED recommend or deliver shock inappropriately.
Even in the isolated environment of the aircraft the
device worked well for VF and was safe even if
used when VF was not present.
Using the AED
Idiot-proof technology
Remove the adhesive backing and place the 2 electrical
patches (not paddles) on the bare chest.
Turn the device on.
The device reads the heart rhythm and gives both a
verbal and a display recommendation to shock if
ventricular fibrillation (VF) is detected.
If a shock is recommended, the person operating the
AED will be instructed to stand back and push the
flashing red button to deliver the shock.
The AED will not deliver a shock if it does not detect VF.
After the shock, the device re-analyses the electrograms
and determines whether another shock is recommended.
American Airlines study
Reliable shocks
In 204 AED uses, the device never inaccurately
recommended a shock, and never failed to detect
VF that required a shock.
In most uses, after tracking the heart rhythm, the
device determined no shock was required.
All but 1 patient was shocked out of VF with a
single shock.
The only case that didn't convert with a single
shock converted with a second shock.
Robert C Kowal MD, presented at the 21st Annual Scientific Sessions of the North
American Society of Pacing and Electrophysiology (NASPE), Washington, DC
Shockable rhythms
Differences between airlines
AED can terminate VF, but survival is effected by the
condition of the heart and the time the patient has been
down.
A flat line or agonal rhythm may imply that the patient was
in arrest long before it was recognized or that the heart is so
sick that it can't be resuscitated; patients who persistently
came out in an agonal rhythm died.
American Airlines had more shockable rhythms than Qantas,
possibly because of the duration of the flights. On the longer
Qantas flights, where more people were found in agonal or
slow rhythms, it is more likely that passengers are assumed
to be asleep, when they may be dead.
This lack of recognition may account for the higher
percentage of slow heart rhythms seen on airlines than in
public places where people are moving around.
Children vs EMTs
Study design
With the use of a mock cardiac arrest scenario, AED
use by 15 6th grade children was compared with that
of 22 emergency medical technicians (EMTs) or
paramedics.
The primary endpoint was time from entry at the
cardiac arrest scene to delivery of the shock into
simulated ventricular fibrillation.
The secondary endpoint was appropriateness of pad
placement.
All performances were videotaped to assess safety of
use and compliance with AED prompts to remain clear
of the mannequin during shock delivery.
Gundry JW, et al. Circulation 1999;100:1703-1707
Children vs EMTs
Study results and conclusions
Mean time to defibrillation
(range), seconds
Children
EMTs/paramedics
90 ± 14 (69–111)
67 ± 10 (50–87)
p value
<0.0001
Electrode pad placement was appropriate for all subjects.
All remained clear of the patient during shock delivery.
The speed of AED use by untrained children was only
modestly slower than that of professionals.
The difference between the groups is surprisingly small,
considering that the children were untutored first-time
users.
These findings suggest that widespread use of AEDs will
require only modest training.
Gundry JW, et al. Circulation 1999;100:1703-1707
Survival statistics
Response time key to survival
Every day more than 600 Americans died from cardiac
arrest.
Chance of survival is reduced by 10% for every minute
of waiting.
All too frequently, by the time the paramedics arrive and
defibrillation is performed it is too late to save the
patient.
Any reasonable individual can probably obtain enough
information from the AED instructions to administer
treatment, which would be better than waiting for
emergency assistance.
According to estimates by the American Heart
Association, 30% of Americans suffering from cardiac
arrest could be saved by immediate treatment with
AEDs.
Cardiac Arrest Survival Act
The House of Representatives passed a bill in 1999
that directs the Department of Health and Human
Services to develop guidelines for installing AEDs in
federal buildings, and granting legal immunity to
those who use them.
President Clinton proposed a new Federal Aviation
Administration (FAA) rule that would require all
commercial airplanes with at least 1 flight attendant
to carry an AED on international and domestic
flights.
http://thomas.loc.gov/cgi-bin/bdquery/z?d106:h.r.02498:
Immunity for AED users
The Cardiac Arrest Survival Act of 1999 provides that
any person who provides emergency medical care
through the use of a defibrillator, any person who
maintained, tested, or provided training in the use of
the device, any physician who provided medical
oversight of the device, and the person who acquired
the device (if specified conditions have been met) is
immune from civil liability for any personal injury or
wrongful death resulting from the provision of such
care, unless the person engaged in gross negligence or
willful or wanton misconduct under the applicable
circumstances.
http://thomas.loc.gov/cgi-bin/bdquery/z?d106:h.r.02498:
Chest compression vs CPR
A Seattle study conducted between 1989 and 1998 looked
at 520 episodes of cardiac arrest.
In a randomized manner, telephone dispatchers gave
bystanders at the scene of apparent cardiac arrest
instructions in either chest compression alone or chest
compression plus mouth-to-mouth ventilation.
Complete instructions were delivered in 62% of episodes
for the group receiving chest compression plus mouth-tomouth ventilation and in 81% of episodes for the group
receiving chest compression alone.
Instructions for compression required 1.4 minutes less to
complete than instructions for compression plus mouth-tomouth ventilation.
Time to response by emergency services averaged 4
minutes, and all units were equipped with automated
defibrillators.
Hallstrom A, et al. N Engl J Med 2000; 342:1546-1553
Chest compression vs CPR
Results
Chest
compression
only (n=241)
Standard
CPR
(n=279)
p
value
Discharged from
hospital alive
14.6%
10.4%
0.18
Admitted to hospital
34.1%
40.2%
0.15
The rates were higher in the group receiving instructions
on chest compression alone, although the differences
were not statistically significant. Outcome was similar for
both types of instructions, but chest compression alone
may be the preferred approach for bystanders
inexperienced in CPR.
Hallstrom A, et al. N Engl J Med 2000; 342:1546-1553