What is the ideal chest compression:ventilation ratio? Ventilation : Perfusion Match Good CPR ~1/4 - 1/3 of normal cardiac output alveolar ventilation ~1/4 - 1/3 of normal Additional breaths “dead space” ventilation Increase IT pressure

CPR ratios Mathematical model Lay rescuers - adult victims 50:2 “best” This mathematic model demonstrates the competing priorities of blood flow and alveolar oxygen. Since the ultimate goal is oxygen delivery to the tissues, the optimal point appears to be at a compression:ventilation ratio of 50:2. Why not use 50:2? The primary concern is rescuer fatigue, with resultant ineffective chest compressions. Babbs, Resuscitation 2004;61

Guidelines 2005- Ventilation Compression/Ventilation Ration 30:2 Deliver each rescue breath over 1 second Give enough volume to produce visible chest rise Avoid rapid and forceful breaths Advanced Airway- give 1 breath every 6-8 seconds 1

Chest Compressions Only Continuous chest compression (CCPR) G U I D E L N S 2 5 Emphasis  effective chest compression defibrillation Chest Compressions Only Continuous chest compression (CCPR) Shock First or CPR First

Survival From Simulated CPR 80 73% 70% 24 hr CNS NORM 40 Ewy- Survival from simulated out-of-hospital cardiac arrest due to single lay rescuer CPR. 7% CC Only IDEAL CPR NO CPR Ewy et al: Circulation 2005;111:2134-42

Probability of Survival to Hospital Discharge Wik, L. et al. JAMA 2003;289:1389-1395.

Defibrillation or CPR First % survival Wik, JAMA 2004

Phases of VF Cardiac Arrest Metabolic Phase GLOBAL ISCHEMIA-INJURY Electrical Phase MINIMAL ISCHEMIA Hemodynamic Phase LOCAL ISCHEMIA RIGHT HEART V-P Weisfelt and Becker. JAMA 2002:228;3035-3038 The three phases cardiac arrest: electrical phase @ 5 minutes, hemodynamic phase @ 15 minutes; metabolic phase. During the hemodynamic phase, most important determinant of cerebral perfusion pressure is the arterial pressure generated during CPR. If early defibrillation is not present, major determinant of survival is production of an adequate CPP. JAMA 2002;288:3035

Phases of VF Cardiac Arrest Metabolic Phase NOVEL THERAPIES NEEDED Electrical Phase EARLY DEFIBRILLATION CRITICAL Hemodynamic Phase CORONARY-CEREBRAL PERFUSION PRESSURE CRITICAL DEFIBRILLATION 4MINS CHEST COMPRESSION HDE 4-10MINS HYPOTHEMRIA CONTROLLED REPERFUSION Weisfelt and Becker. JAMA 2002:228;3035-3038 The three phases cardiac arrest: electrical phase @ 5 minutes, hemodynamic phase @ 15 minutes; metabolic phase. During the hemodynamic phase, most important determinant of cerebral perfusion pressure is the arterial pressure generated during CPR. If early defibrillation is not present, major determinant of survival is production of an adequate CPP. JAMA 2002;288:3035

CPR before Defibrillation Guidelines 2005- CPR before Defibrillation Immediate defibrillation is the treatment of choice for VF of short duration OOH unwitnessed (EMS) VF, may give period CPR before rhythm check 1

Single or Stacked Shocks Pulse Check Rhythm Check 2 5 Emphasis  effective chest compression defibrillation Single or Stacked Shocks Pulse Check Rhythm Check

Major Recommendations G U I D E L N S 2 5 Major Recommendations Single shock Followed by immediate CPR

22 seconds after pads placed 1st Shock delivered 22 seconds after pads placed

RE-VF 25 seconds after the 1st shock (No Chest Compressions yet)

2nd Shock delivered 34 sec after re-VF (Still No Chest Compressions) CPR finally begun after 1 min 17 sec from 1st shock

Monophasic vs Biphasic Waveform Shock Efficacy VF Waveform Energy 1st 2nd 3rd 54 BTE 150, 150,150 96% 98% 48 MTE 200, 200, 360 54% 60% 67% 13 MDS 77% No waveform consistently related to  ROSC or Hospital Discharge

Defibrillation Success Out-of-Hospital Cardiac Arrest First Shock Results (N=21/61) Remained in VF- 19% Shocked into Non-VF 81% Perfusing rhythm  0% 21/61 (34%) received Defib shock(s) @TIME RESUME CPR – 45 SECONDS Kern Circulation 2002

Prompt CPR after AED ‘p’ <0.05 Percent 10/18 9/18 9/18 Kern 3/18

Will CPR Do Harm Post-Shock Most ‘post-shock” PEA is “pseudo-PEA” -some pressure generated (~10/5 or 20/10 mmHg) -undetectable as a palpable pulse (Aufderheide/Monday) Chest Compressions during post-shock organized rhythms does not precipitate re-VF (Hess & White)

CPR after Defibrillation Guidelines 2005- CPR after Defibrillation Resume CPR immediately following shock (and while charging) No pulse or rhythm check for 5 cycles CPR (@ 2 minutes) 1

ACLS Major Recommendations G U I D E L N S 2 5 ACLS Major Recommendations  Emphasis advanced airway Recommendation Intraosseous access  Emphasis ET drug administration

ACLS PRIORITIES 2 MINUTE CYCLES- TEAM DYNAMICS

ECC – New Course Emphasis Team Dynamics and Leadership Outcome is determined by success of team and not the individual

ACLS Major Recommendations G U I D E L N S 2 5 ACLS Major Recommendations Amiodarone – Lidocaine either Epinephrine- Vasopressin ET discouraged Atropine 0.5 mg - ACS

Summary ACLS Emphasis on High-Quality CPR Simplified Algorithms 2 5 Summary ACLS Emphasis on High-Quality CPR Simplified Algorithms Recommend expert consultation Use IV / IO Access limit ET administration Limit, defer Advanced Airway Use Especially endotracheal tube Primary confirmation of ET- dual method

Key studies- Amiodarone ARREST TRIAL Kudenchuck 1999 Patient group n Survival to admission Odds ratio for admission Survival to discharge Amiodarone 246 44 % 1.6 13.4 % Placebo 258 34 % (p = 0.03) (p = 0.02) 13.2 % (p = ns.) ALIVE TRIAL Dorian 2002 amiodarone 5 mg/kg vs. lidocaine 1.5 mg/kg) Patient group n Survival to admission Survival to discharge Amiodarone 180 22.8 % 5 % Lidocaine 167 12.0 % (p = 0.009) 3 % (p = 0.34)

Vasopressin-Epinephrine Group n ROSC Survival admission ≥ 24 h discharge Vasopressin 20 80 % 70 % 60 % 40 % Epinephrine 55 % (p = 0.18) 35 % (p = 0.06) 20 % (p = 0.02) 15 % (p = 0.16) Lindner 1997

Vasopressin-Epinephrine Patient group (all rhythms) n Survival to 1 hour Survival to discharge Vasopressin 104 39 % 12 % Epinephrine 96 35 % (p = 0.66) 14 % (p = 0.67) PEA n = 95 Survival to 1 hour discharge Vasopressin 33 % 9 % Epinephrine 29 % 10 % Stiell 2001

Vasopressin-Epinephrine VF/VT (n = 42) Survival 1 hour discharge Vasopressin 54 % 25 % Epinephrine 61 % 33 % Stiell 2001 VF/VT (n = 188) ROSC Survival admission Survival discharge Vasopressin 36.8 % 46.2 % 17.8 % Epinephrine 42.6 % (p = 0.20) 43.0 % (p = 0.48) 19.2 % (p = 0.70) Wenzel 2004

Patient group (all rhythms) Vasopressin-Epinephrine Patient group (all rhythms) n ROSC Survival admission Survival discharge Vasopressin 589 24.6 % 36.3 % 9.9 % Epinephrine 597 28.0 % (p = 0.19) 31.2 % (p = 0.06) (p = 0.99) Subgroup with PEA n = 186 N=186 ROSC Survival admission Survival discharge Vasopressin 104 20.2 % 33.7 % 5.9 % Epinephrine 82 20.7 % (p = 0.93) 30.5 % (p = 0.65) 8.6 % (p = 0.47) Wenzel 2004

Summary BLS HCP Lone HCP- Tailor Sequence Actions G U I D E L N S 2 5 Summary BLS HCP Lone HCP- Tailor Sequence Actions Check for Adequate Breathing Open airway in trauma patients Avoid Excessive Ventilation (too fast, too much) 1 breath Q 8-10secs 30:2 compression ventilation ratio Continuous CPR with advanced airway Rescuers rotate every two seconds Push hard, push fast, allow full chest recoil Pulse check >5  10 seconds