Case 3 Shock-Resistant VF/Pulseless VT © 2001 American Heart Association 1

Case 3 A 60-year-old ECG technician collapses while attaching a 12-lead ECG to a patient. The technician has not complained of discomfort before her collapse. A colleague begins CPR immediately. Describe how you would direct the management of this patient.

Learning Objectives Describe the steps of the ACLS Approach. Describe the Primary ABCD Survey used to assess and give initial treatment (CPR and initial defibrillation shocks) to a victim who is unresponsive and breathless, with no signs of circulation. Describe how with unsuccessful attempts at defibrillation you immediately apply the Secondary ABCD Survey and provide advanced management of the airway, effective ventilation, continued chest compressions, and appropriate IV drugs—all integrated with repeated attempts to defibrillate.

Learning Objectives The successful ACLS provider should be able to Manage 1st 10 minutes of a witnessed VF/pulseless VT arrest (guided by Primary and Secondary ABCD Surveys) Initiate CPR if not already started Use an AED or manual defibrillator when available Assign resuscitation team roles as more ACLS providers become available: 2nd rescuer: helps with CPR 3rd rescuer: assumes airway control 4th rescuer: obtains IV access Select appropriate adrenergic agents and antiarrhythmics, other agents

Skills to Learn At the end of Case 3 the ACLS provider should be able to demonstrate Correct attachment of ECG monitor leads Defibrillation with conventional defibrillator Administration of medications by tracheal tube Delivery of IV fluids and medications Ability to provide direction to resuscitation team

New Rhythms to Learn At the end of Case 3 the ACLS provider should be able to recognize: Ventricular fibrillation (VF) Ventricular tachycardia (VT) ECG artifact that looks like VF

Drugs to Learn ECC Handbook Describe indications, contraindications, dosages for: Epinephrine Vasopressin Amiodarone Lidocaine Magnesium sulfate Procainamide Sodium bicarbonate ECC Handbook Because the VF/VT Algorithm contains a new adrenergic-like drug (vasopressin) and a new antiarrhythmic agent (amiodarone), the algorithm has gotten more complicated. It has some subtle features that require careful attention. Point out the adjective persistent before VF/pulseless VT––defined as VF that continues without any intervening non-VF rhythms even after 3 defibrillatory shocks. Note the term recurrent in the algorithm––defined as VF that responded at least once to a shock with a post-shock, non-VF rhythm. ACLS providers then must check for a pulse to determine whether the post-shock, non-VF rhythm should be classified as “with a pulse” or “without a pulse.” This would just be semantic quibbles were it not for the clinical importance of these distinctions and the fact that the treatments used differ according to the semantic classification. Ask “Does the non-VF rhythm produce a pulse?”

Primary ABCD Survey Focus: Basic CPR and Defibrillation 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 are the same when you respond to any potential cardiorespiratory emergency: Assess rescuer and victim safety. Assess responsiveness. “Phone fast.” Position the victim. Position yourself as the rescuer. Primary ABCD Survey Check the ABCs. Perform CPR until the defibrillator is attached for defibrillation. Assess the rhythm, hunting for VF. Deliver defibrillatory shocks in close sequence: shock 1: 200 J; shock 2: 200 to 300 J; shock 3: up to 360 J if VF is persistent.

VF/Pulseless VT Check responsiveness A Airway: open the airway B Breathing: provide positive-pressure ventilations C Circulation: give chest compressions D Defibrillation: assess for and shock VF/pulseless VT, up to 3 times (200 J, 200 to 300 J, 360 J, or equivalent biphasic) if necessary Primary ABCD Survey Focus: basic CPR and defibrillation Check responsiveness Activate emergency response system Call for defibrillator Rhythm after first 3 shocks?

What’s New in Defibrillation? (Walcott et al. Circulation. 1998;98:2210-2215) 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

Secondary ABCD Survey A = Airway: place airway device as soon as possible B = Breathing: confirm proper placement by PE B = Breathing: confirm proper placement by 2nd method End-tidal CO2 and/or Esophageal detector devices B = Breathing: prevent airway device dislodgment: Use purpose-made tube holder Proven tape-and-tie or other technique B = Breathing: monitor oxygenation and ventilation If VF/pulseless VT persists after 3 shocks, the ACLS provider moves to the Secondary ABCD Survey to manage the Airway, provide invasive Breathing, and treat the (lack of) Circulation. The Secondary ABCD Survey for the VF/Pulseless VT Algorithm is, for treatment purposes, the same for all 3 cardiac arrest algorithms: advanced airway management, effective ventilation, access to the bloodstream, and administration of rhythm-appropriate medications. The effective team leader will have already assigned 4 tasks at the start of resuscitation: A rescuer to perform chest compressions A rescuer to manage the airway, including ventilation adjuncts and advanced airway control A rescuer to establish IV or IO access for medication administration A rescuer to initiate rhythm monitoring and to perform defibrillation

Secondary ABCD Survey (cont’d) C = Circulation: establish IV access C = Circulation: identify rhythm C = Circulation: give rhythm- and condition-appropriate drugs D = Differential Diagnosis: search for and treat identified reversible causes

VF/Pulseless VT (cont’d) Persistent or recurrent VF/VT Secondary ABCD Survey Focus: more advanced assessments and treatments A Airway: place airway device as soon as possible B Breathing: confirm airway device placement by exam plus confirmation device B Breathing: secure airway device; purpose-made tube holders preferred B Breathing: confirm effective oxygenation and ventilation C Circulation: establish IV access C Circulation: identify rhythm  monitor C Circulation: administer drugs appropriate for rhythm and condition D Differential Diagnosis: search for and treat identified reversible causes

Ventricular Fibrillation Characteristics of VF Organized QRS complexes and absent P waves Wavy, chaotic, inconsistent baseline Irregular rhythm VF may occur spontaneously or be preceded by VT.

Ventricular Tachycardia Characteristics of VT Wide, bizarre QRS complexes Regular rhythm and mostly uniform in shape Absent P waves Ventricular rate is 150 bpm. How is the patient tolerating this rhythm? Does this produce a pulse? Cases 8 and 9 discuss patients with VT rhythms that are associated with a pulse.

Shock-Resistant VF/Pulseless VT Does patient show persistent or recurrent VF/VT? After IV is started: vasopressin or epinephrine? Consider antiarrhythmics: use amiodarone? lidocaine? procainamide? magnesium?

VF/Pulseless VT (cont’d) ? Epinephrine 1 mg IV push, repeat every 3 to 5 minutes or Vasopressin 40 U IV, single dose, 1 time only Resume attempts to defibrillate 1 x 360 J (or equivalent biphasic) within 30 to 60 seconds Consider antiarrhythmics: Amiodarone (llb for persistent or recurrent VF/pulseless VT) Lidocaine (Indeterminate for persistent or recurrent VF/pulseless VT) Magnesium (llb if known hypomagnesemic state) Procainamide (Indeterminate for persistent VF/pulseless VT; llb for recurrent VF/pulseless VT) Epinephrine (Class Indeterminate) 1 mg IV push every 3 to 5 minutes. If this fails, higher doses of epinephrine (up to 0.2 mg/kg) are acceptable but not recommended (there is growing evidence that it may be harmful). Vasopressin is recommended only for VF/VT; there is no evidence to support its use in asystole or PEA. There is no evidence about The value of repeated vasopressin doses or The best approach after the first single bolus of vasopressin As a Class Indeterminate action, it is acceptable to resume epinephrine 1 mg IV push every 3 to 5 minutes if there was no response in 5 to 10 minutes to a single IV dose of vasopressin. The evidence for this approach is based on rational conjecture. Suggestion to instructors Resist the requests to tell the learners whether you prefer epinephrine or vasopressin. The evidence, as of 2001, makes them equivalent, with vasopressin, as a nonadrenergic agent, associated with fewer adverse side effects. The supply chain from production to widespread distribution throughout all hospitals and the EMS system has been slow to develop. Resume attempts to defibrillate

VF/Pulseless VT (cont’d) Epinephrine 1 mg IV push, repeat every 3 to 5 minutes or Vasopressin 40 U IV, single dose, 1 time only Resume attempts to defibrillate 1 x 360 J (or equivalent biphasic) within 30 to 60 seconds ? Consider antiarrhythmics: Amiodarone (llb for persistent or recurrent VF/pulseless VT) Lidocaine (Indeterminate for persistent or recurrent VF/pulseless VT) Magnesium (llb if known hypomagnesemic state) Procainamide (Indeterminate for persistent VF/pulseless VT; llb for recurrent VF/pulseless VT) CONSIDER ANTIARRHYTHMICS is a heading very carefully chosen to represent what has been confirmed about these agents for VF still present after 3 shocks. Consider their use, but do not do so thinking they are going to have a significant effect. Since all agents in box 3 are Class IIb or Class Indeterminate, a clinician can decide to forgo giving any antiarrhythmics. This would be well within the standard of care for this condition (persistent VF after 3 or more shocks).   Antiarrhythmics are Indeterminate or Class IIb (acceptable); only fair evidence supports possible benefit of antiarrhythmics for shock-refractory VF/VT. Amiodarone (Class IIb) 300 mg IV push (cardiac arrest dose). If VF/pulseless VT recurs, consider administration of a second dose of 150 mg IV. Maximum cumulative dose: 2.2 g over 24 hours. Lidocaine (Class Indeterminate) 1.0 to 1.5 mg/kg IV push. Consider repeating in 3 to 5 minutes to a maximum cumulative dose of 3 mg/kg. A single dose of 1.5 mg/kg in cardiac arrest is acceptable. Magnesium sulfate 1 to 2 g IV in polymorphic VT (torsades de pointes) and suspected hypomagnesemic state. Procainamide (Class IIb) 30 mg/min in recurrent VF/pulseless VT (maximum total dose: 17 mg/kg). Procainamide provides the most benefit when the periods of VF are interrupted by at least several minutes of a non-VF rhythm with a pulse. Think of trying to “load” the patient with the procainamide during the periods of having a pulse. Procainamide is Class Indeterminate for persistent VF/pulseless VT. Although acceptable, it is not recommended for persistent VF because prolonged administration time is problematic. Resume defibrillation attempts. Use 360-J (or equivalent biphasic) shocks after each medication or after each minute of CPR. Acceptable patterns: CPR-drug-shock (repeat) or CPR-drug-shock-shock-shock (repeat). Resume attempts to defibrillate

VF/Pulseless VT: Return of Spontaneous Circulation Let Secondary ABCD Survey Guide Postresuscitation Care A = maintain open, protected airway A = stabilize airway devices during transport; avoid dislodgment B = monitor ventilation (CO2) and oxygenation (O2) C = monitor rhythm; give rhythm-appropriate medications D = if defibrillation occurred after use of antiarrhythmic agent, then continue maintenance infusion of same agent C = to maintain BP and HR: use dopamine or dobutamine (avoid epinephrine, isoproterenol, norepinephrine)