UPDATE ON EMERGENCY CARDIAC CARE GUIDELINES

1
UPDATE ON EMERGENCY CARDIAC CARE GUIDELINES

• Mark L. Greenberg, MD
• Associate Professor of Medicine
• Director, Clinical Electrophysiology and Pacing

2
BLS and ACLS--Historical Perspective

• 1956 External defibrillation (Zoll)
• 1958 Mouth-to-mouth ventilation (Safar, Elam)
• 1960 Chest compressions (Kouwenhoven)
• 1979 Automatic External Defibrillator (AED)
  (Diack)
• 1996 Biphasic waveform approved for AED use in
  USA
• 2000 First international evidence-based
  resuscitation guidelines

1
3
The Chain of Survival of Cardiopulmonary
Resuscitation
4
Interdependence of Early CPR and Early
Defibrillation
5
The physiologic mechanism of chest compressions
cardiac pump (A) or thoracic pump (B)?
6
Whats New in BLS

• New Chest Compression Rate and Compression-Ventila
  tion Ratio for Adults
• Interposed Abdominal Compression CPR (IAC-CPR)

7
INTERRUPTIONS IN CHEST COMPRESSIONS ARE
DETRIMENTAL

• Lay rescuers 16 seconds to administer 2 breaths
  (cf 3-4 sec. for professionals).
• Compression ventilation ratio of 51 yields
  higher PaO2 but lower oxygen delivery than 152
  (64 compressions, 8 ventilations per minute).

8
New Chest Compression Rate and Compression-Ventila
tion Ratio for Adults

• Compression rate approx. 100/min for adults and
  children over age one
• Compression-ventilation ratio 152 for both one
  and two-rescuer CPR (51 after trachea intubated)

9
Interposed Abdominal Compression CPR (IAC-CPR)

• An alternative for in-hospital resuscitation
• Abdomen compressed between xiphoid and umbilicus
  during relaxation phase of chest compression
• Increases forward blood flow during CPR and
  appears to improve survival

10
IAC-CPR
11
Seesaw-like Function of the Lifestick
12
ResQPump
Metronome
Force Gauge
Suction Cup
Handle
13
Inspiratory Impedance Threshold Valve (ITV)

• Concept Lower intrathoracic pressure in the
  chest during the decompression phase of CPR
  enhances venous return to the thorax.

• Design Each time the chest wall recoils
  following a compression, the ITV transiently
  blocks air/oxygen from entering the lungs,
  creating a small vacuum in the chest.

14
ResQValveä (CPRx)

• Disposable, one-way valve that fits into the
  respiratory circuit and impedes inspiratory gas
  exchange during decompression

15
ResQValve Placement
16
Blood Flow During CPR (Porcine VF Model)
Blood Flow (ml/min/gm)
Brain
Left Ventricle
Lurie et al. Improving ACD CPR with an
inspiratory impedance valve. Circulation
1995911629-32.
17
Blood Pressure During CPR in Humans
120
100
STD CPR
80
mmHg
60
ACD ITV
40
20
Baseline (Normal)
0
Systolic
Diastolic
Cohen et al, JAMA 1992 and Plaisance et al,
Circulation 2000

18
RCT of ACD/ITV CPR vs. STANDARD CPR

• 220 patients, 157 with witnessed events (Mainz,
  Germany)
• 24 hr. survival 37 with ACD/ITV CPR vs. 22 with
  standard CPR (p0.03)

Wolcke et. al. Circulation.2002106II-538.
19
Whats New in External Defibrillation

• More emphasis on early defibrillation
• Automatic External Defibrillation (AED) and
  Public Access Defibrillation (PAD)
• Defibrillation with a biphasic waveform

20
Defibrillation The Time Factor
Survival rates after VF cardiac arrest
decrease approximately 7 to 10 with every
minute that defibrillation is delayed.
Non-linear
Guidelines 2000 for Cardiovascular Resuscitation
and Emergency Cardiovascular Care.Circulation.
2000102(suppl I)8. August 22,2000
21
13 year old boy struck by a pitch

• Commotio Cordis

22
Goals For Early Defibrillation

• In hospital defibrillation within 3 minutes
• Out of hospital defibrillation within 5 minutes
  of activation of the EMS (value of AED and PAD)

23
(No Transcript)
24
Unconscious patient, no pulse

• Shock advised

25
Unconscious patient, no pulse

• No shock advised?

26
It is time for the national government to help
bring AEDs to public places all over America. .
. I am working with Congress to complete a vital
piece of legislation that would not only
encourage the installation of AEDs in federal
buildings, but also grant legal immunity to good
Samaritans who use them. .. It is now our
responsibility to bring this technology , this
modern miracle, to every community in America.
27
Prevalence of AEDs

• National Registry of CPR Hospitals 31
• VA Hospitals 14
• Commerical Airliners 100

28
OHare International Airport 60-90 Second Walk
To An AED
Caffrey et. al. N Engl J Med 20023471242-7.
29
CHICAGO AIRPORT AED STUDY

• Three airports, serving gt100 million
  passengers/yr.
• 21 cardiac arrests over 2 yrs 18 had VF, 11 of
  whom were resuscitated (10 alive well one yr.
  later)

Caffrey et. al. N Engl J Med 20023471242-7.
30
Incidence of Unexpected Cardiac Arrest
31
(No Transcript)
32
AEDs UNANSWERED QUESTIONS

• Does formal training improve performance?
• How are they best deployed?
• Are they cost effective?

33
DEFIBRILLATOR WAVEFORMS
34
DefibrillationCurrent Flow

• Biphasic defibrillationcurrent flows in two
  phases, first in one direction from one
  electrode, and then current flows the other way
  from the other electrode

35
Biphasic DefibrillationRisk of Damage
40
Monophasic Peak Current
30
40 Difference
Biphasic Peak Current
20
Current (amps)
10
0
-10
-20
0
5
10
15
20
Time (msec)
Much less peak current and better efficacy than
monophasic
Source SL Higgins, Prehospital Emergency Care
2000 4305-313
36
Transthoracic Impedance

• Measured by the defibrillator
• Higher impedance
• Skin surfaceespecially dry
• Hair
• Fat
• Bone
• Air in chest

37
Impedance
The current a heart receives from a 200J shock
depends on the patients impedance
38
Impedance Distribution
Histogram of patient impedances
16
14
12
10
8
Percentage of Patients
6
4
2
0
30
40
50
60
70
80
90
100
110
120
130
140
150
More
Impedance (ohms)
Medtronic Physio-Control Impedance data on 723
SCA patients.
39
Biphasic Defibrillators Are NOT All the Same

• Waveforms vary (with regard to voltage or pulse
  duration) in their response to transthoracic
  impedance measurements.
• Energy settings may be fixed, low-dose
  escalating, or standard dose escalating.
• No clear superiority among manufacturers.

40
IMPEDANCE ADJUSTMENT WITH PHILIPS FR2
50

• SMART Biphasic
• 150-150-150 J
• Current adjusted for impedance
• Customized waveform shape for each patient and
  each shock

40
50?, 150 J
30
75?, 150 J
20
Current (A)
125?, 150 J
10
0
-10
-20
0
5
10
15
20
25
30
35
40
Time (msec)
41
Why Will Biphasic Defibrillators Replace Standard
Monophasic Models?

• Impedance compensating, lower shock strength
  biphasic waveforms have less potential to damage
  cells.
• Biphasic waveforms have superior efficacy for
  treating atrial fibrillation and ventricular
  fibrillation.

42
Randomized, controlled trial of 150 J biphasic
shocks with 200-360 J monophasic shocks in 115
patients with out-of-hospital VF time to first
shock 8.9/-3.0 min.
.
p lt 0.0001
98 (53/54)
p lt0.0001
96 (52/54)
69 (42/61)
59(36/61)B

Biphasic
Biphasic
Monophasic
Monophasic
1st shock
3 shocks
Schneider T, et al, Circulation
20001021780-1787.
43
Whats New in ACLS?

• Airway Management
• Vasopressin
• IV amiodarone as a first-line drug

44
Whats New in Airway Management

• Emphasis on skilled bag-mask ventilation with
  continuous cricoid pressure
• Validation of airway adjuncts like the laryngeal
  mask and Combitube
• Recommendation for secondary confirmation
  techniques to verify ETT placement (e.g.end-tidal
  CO2)

45
Cricoid Pressure Can Minimize Gastric Inflation
46
Advanced Airway Devices

• Esophageal-tracheal combitube

47
Advanced Airway Devices

• Laryngeal mask airway (LMA)
• Superior to ETT for BLS-level personnel
• Equal to ETT for ACLS-level personnel

48
Laryngeal Mask
49
Confirming Tracheal Tube Placement

• Esophageal detector devices

50
Vasopressin 40 U IV Before Epinephrine 1 mg IV?

• Vasopressin appears at least as effective as
  epinephrine (large RCT underway in Europe).
• Vasopressin is non-beta-adrenergic and does not
  increase myocardial 02 consumption.
• Longer half-life (10-20 min. vs. 3-5 min.)
  simplifies administration.

51
Amiodarone 300 mg IV Should Be Given Before
Lidocaine

• Advantage lidocaine rapid onset of action, no
  hypotension
• Game, set, and match amiodarone minimal
  proarrhythmia, much stronger evidence for
  efficacy

52
Amiodarone vs. Placebo in 504 Pts. with Shock
Refractory Out-of-Hospital VT/VF
53
Amiodarone vs. Lidocaine for Shock-Resistant VF
Dorian et al. N Engl J Med 2002346884-90.
54
Stable Ventricular Tachycardia
55
Polymorphic Ventricular Tachycardia