ACLS: Year 2000 Guidelines Analysis

This report is based on final published ACLS changes reported in 
Circulation Supplement for August 22, 2000. All readers are 
encouraged to read the findings for themselves-this review is not 
meant to be comprehensive nor should it substitute for an ACLS 
provider's own inquiry into these subjects, issues and 
recommendations. This material in Circulation represents a process 
of intensive review and consensus begun well over 18 months ago. 
A "roll out" took place in September 21-24 in San Diego where 
this information was further explained and how it will be 
incorporated in ACLS changes will be presented. This, then represents 
the content that the San Diego conference will be based upon..

Chris Perrin, ACUTE CARE, INC. Director of Education

SEE ALSO: 
American Heart Association Guidelines 2000 Archive
PBLS (Pediatric Basic Life Support)
Adult BLS (Basic Life Support),
Ethical Aspects of CPR and ECC,
Post-Resuscitation, Acute Coronary Syndromes and CVA, 
ACLS Rollout Agenda and Equipment List, 
and PALS (Pediatric Advanced Life Support)

CONTENTS

Introduction

Definitions of Classes

Airway and oxygenation

Added 11/2/2000: INFORMATION ON THE Laryngeal Mask Airway

Defibrillation

Assisting Circulation

Arrhythmias

Pharmacology

"A good resuscitation team is like a symphony orchestra"

Family presence in resuscitation

DNR vs DNAR

ILCOR universal/international algorithm

ECC Comprehensive Algorithm

Pulseless VT/VF algorithm

Tachycardia

What’s New is highlighted in red

Introduction

These most recently released guidelines for ACLS are--

Evidenced-based;

International (at least 40% non-US representation);

Guidelines are no longer simply "descriptive" but now are "prescriptive."

Note--the actual process of evidence evaluation used in this 2000 Conference 
will be published in Annals of Emergency Medicine soon.

Throughout the Guidelines, the following definitions of classes of 
recommendations are used:

Class I recommendations are always acceptable. They are proven 
safe and definitely useful, and they are supported by excellent 
evidence from at least one prospective, randomized controlled 
clinical trial

Class IIa recommendations are considered acceptable and useful 
with good to very good evidence providing support. The weight of 
evidence and expert opinions strongly favor these interventions.

Class IIb recommendations are considered acceptable and useful with 
weak or only fair evidence providing support. The weight of evidence 
and expert opinion are not strongly in favor of the intervention.

Class III refers to interventions that are unacceptable. These 
interventions lack any evidence of benefit, and often the evidence 
suggests or confirms harm.

Class Indeterminate refers to an intervention that is promising, but 
the evidence is insufficient in quantity and/or quality to support a 
definitive class of recommendation. The Indeterminate Class was 
added to indicate interventions that are considered safe and perhaps 
effective and are recommended by expert consensus. However, the 
available evidence supporting the recommendation is either too weak 
or too limited at present to make a definitive recommendation based 
on the published data.

Airway and oxygenation

AMI patients-recommend O2 4/lpm per nasal cannula for at least first 2-3 hours (IIa);

Adequate ventilation with a BVM---currently 10ml/kg (700-1000ml)—several studies suggest 6-7ml (approx. 500ml delivers adequate tidal volumes with BVM in unintubated patients (IIa);

Intubate only if trained and plenty of practice otherwise use LMA or ETC (both IIa);

COPA (cuffed oropharangeal airway) may be another device useful for those who cannot intubate;  

Added 11/2/2000: INFORMATION ON THE Layrngeal Mask Airway

Interrupt ventilations a maximum of 30 seconds for intubation, if unsuccessful   reventilate 15-30 seconds before trying again;

Inflate while auscultating during normal ventilation through ET tube---inflate to seal out audible air leak (usually 10ccs):

Correct initial and ongoing placement of the ET tube is an emphasized concern in the new guidelines;

Confirm tube placement with CO2 detectors or esophageal detection devices as well as with auscultation  over epigastrium, midaxillary, and anterior chest line right and left sides after placement (esophageal detection devices—use with caution with morbid obesity, late pregnancy and status asthmaticus---CO2 detectors use with caution with possible PE and with patients consuming carbonated beverages prior to arrest);

ATMs-automatic transport ventilators-time or volume cycled (not pressure-based)effective and  (even if patient is not intubated) seem appropriate;

Oxygen powered, manually triggered (“demand valve”) devices ‘are not recommended at this time” (Class Indeterminate)---need more studies. 

Defibrillation

Continued emphasis on the importance of early defibrillation--“All healthcare  providers with a duty to perform CPR should be trained, equipped, and encouraged to perform defibrillation (Class IIa). The Guidelines 2000 Conference recommends that early defibrillation be available throughout all hospital and outpatient medical facilities (Class IIa). The use of defibrillation now transcends both ACLS and BLS care.”

Continued support regarding biphasic wave forms;

No conclusive data to support fixed vs. escalating energy settings for the newer biphasic defibrillators; investigations continue on---effective waveform types as damped sinusoidal, truncated exponential, and rectilinear first pulse variants, and issues of transthoracic impedance (resistance) and current-based decisions (amperes vs. joules);

Quick –look paddles in initial rhythm identification (to avoid delays) are acceptable;

Cardioversion—atrial fibrillation 100-200J; atrial flutter and PSVT 50-100J; monomorphic VT 100J, polymorphic VT 200J (though energy settings for biphasic waveforms does not have enough data for recommendations to be made.

Assisting Circulation

Important to differentiate between what is appropriate for the lay public and what is appropriate for health care professionals--most of the following are relegated to specially trained individuals. Many of the following alternatives have shown some degree of success in short-term (improved blood flow, increased incidence of pulse return, etc.) but outcome improvement/increased survival data is lacking;

IAC-CPR-interposed abdominal compression-CPR-“recommended as an alternative to  conventional CPR whenever sufficient personnel are available and trained in this technique (Class IIb).” Safety not established for aortic aneuryism, pregnancy, or recent abdominal surgery. Randomized trials “have demonstrated improved outcome when IAC-CPR was compared with standard CPR for in-hospital resuscitation, but no survival benefit for out-of-hospital arrest has been shown.” Safety has been reviewed, no increase in emesis or aspiration.

High-frequency CPR-rates greater than 100 per minute-“shows some promise fpr improving CPR” but further study and outcomes research needed (Class Indeterminate).

ACD-CPR active compression decompression CPR (aka “plunger” CPR). Complications (eg., rib fractures) are “noteworthy  but not of major concern”…some have commented about possible rescuer fatigue. “ACD-CPR is considered an acceptable alternative to standard CPR when rescue personnel adequately trained in use of this device are available(Class IIb)…not proved effective in the out-of-hospital setting: acceptable but weak data supports in-hospital use.”

Vest CPR-“Vest CPR may be considered an alternative to standard CPR in-hospital or during ambulance transport…(Class IIb).” FDA permission to distribute and sell  has not yet been sought for this.

Mechanical CPR (eg., “Thumper”)-“The mechanical resuscitator is an acceptable alternative to standard manual CPR in circumstances that make chest compressions difficult, ie, cedrtain transport situations or lack of adequate personnel (Class IIb).”

SVC-CPR-simultaneous ventilation-compression CPR-…clinical studies have failed to identify any benefits of SVC-CPR…[it] is not currently available for clinical use.”

PTACD-CPR-phased thoracic-abdominal compression-decompression CPR-a hand-held device that combines IAC with ACD CPR. [article’s author note- appears to have been such a device that obtained recent approval by FDA—two years to marketplace?] As of this publishing, no clinical data available (Class Indeterminate).

Impedance threshold valve-(eg., ResQ Valve) adjunct used with intubated ACD patient (prevents inspiration during chest decompression with ACD) “…acceptable as an adjunct to be used with [ACD] device to augment hemodynamic parameters (Class IIb).”

Invasive-open chest CPR-“…can be considered under special circumstances but should not be done simply as a late last-ditch effort (Class IIb).”

Emergency cardiopulmonary bypass-(Class Indeterminate)…its success in special situations of drug overdoses and hypothermic arrest may be sufficient justification alone for its use in specific hospital settings.”

Pulse checks-results from pulse checks during CPR may be misleading—femoral pulse checks may reveal retrograde venous rather than arterial blood flow, and no studies exist that compare pulse findings during CPR with outcomes in terms of predictability;

Arterial blood gases can be useful in evaluating oxygenation but should not be used to assess the adequacy of  CPR

“End-tidal CO2 monitoring can be useful as a noninvasive indicator of cardiac output generated during CPR (Class IIa).”

CPR Plus-a metronome-like device placed on the chest (for rate and force of compressions information) has promising manikin performance results, but lacks in animal or human data (Class Indeterminate)

Arrhythmias

ACLS providers should be able to recognize the variety of dyrhythmias of the past with a substantial amount of alteration and emphasis on the recognition and management of tachycardias; 

Classification of various tachycardias

Narrow complex/supraventricular--Sinus tach, atrial fib, atrial flutter, atrial tach (ectopic, reentrant), multifocal atrial tachycardia, AV nodal reentry tachycardia, junctional  tach, accessory pathway-medicated tachycardia (atrial tach, atrial fib/flutter, AV reentry tachycardia)

Wide complex --Ventricular tachycardia, ventricular fibrillation, SVT with aberration (BBB or intraventricular conduction delay)

If a tachycardia results in pulselessness, shock, or congestive heart failure it should be presumed to be VT until 12-lead (and possibly an esophageal lead) are obtained

Initial care providers are wrong more than 50% of the time in determining whether a wide complex tachycardia is ventricular vs. supraventricular

In the past, lidocaine and adenosine have been given diagnostically to discriminate between SVT and VT of wide complex configurations. It is not effective and is inappropriate to do this. 

Pharmacology

Peripheral IV drugs  require 1-2 minutes to reach central circulation—continue to follow them with a 20 ml bolus of fluid and elevate the extremity 10-20 seconds; endotracheal drug administration  (at 2-2.5 times the IV dose) appears to be unchanged as an alternative (for epinephrine, lidocaine, and atropine)—dilute these in 10ml of normal saline. 

Amiodarone-Class IIb—“helpful” for ventricular control of rapid atrial rhythms with severe LV impairment and digitalis has not worked; cardiac arrest with persisitent VT/VF after defibrillation and initial dose of epinephrine, hemodynamically stable VT, polymorphic VT, and wide complex/unknown origin, atrial tachycardia, ventricular rate in preexitation atrial arrythmias. It is Class IIa for AF and in conjunction with cardioversion for refractory PSVTs.

In non-arrest situations it is given as 150mg over 10 minutes followed by a 1mg/min infusion for six hours and then reduced to a 0.5mg/min infusion. Additional doses of 150mg can be given up to a total daily dose of 2 grams. (One study cited success with AF when amiodarone was administered at 125mg/hr for 24 hours (a total of 3 grams). In pulseless VT/VF it is 300mg diluted in 20-30ml and given rapid infusion; supplemental doses of 150mg may be given for recurrent VT/VF followed by a similar infusion schedule listed above (2 gram total) 

Atropine-Class IIa for all but Mobitz type II and 3^rd degree blocks with new wide QRS complexes. It is not indicated for the latter two. Dosing remains the same as in previous guideline—3 mg is vagolytic and should be reserved for cardiac arrest patients. 

Beta blockers-Class I for non-Q wave AMI and unstable angina. Atenolol, metoprolol, and propanolol effective at reducing occurance of VF in fibrinolytic-ineliglible post MI patients. Esmolol is Class I for treating PSVT, AF or atrial flutter without preexcitation, and Class IIb for ectopic atrial tachycardia, symptomaitc sinus tachycardia, myocardial ischemia and torsades de pointes (in conjunction with pacing). 

Bretylium has been dropped from recommendations (despite remaining IIb) because of supply problems and “availability of safer agents” and its “high occurance of side effects.” 

Calcium channel blockers-may assist in ventricular control in AF, atrial flutter and MAT. Dosing remains unchanged, diltiazem “seems to be equivalent in efficacy to verapamil. Diltiazem offers the advantage of producing less myocardial depression than verapamil.” 

Dopamine-role in bradycardia after pacing/atropine unchanged. May be effective in doses of 3-7.5 mcg/kg/min, though recommended for 5-20 mcg/kg/min 

Isoproterenol-temporizing agent for torsades de pointes before pacing (Class Indeterminate) and Class IIb after pacing, atropine and dopamine in bradycardia. Same dosing (higher infusion rates are Class III). 

Lidocaine-Class Indeterminate for VF/pulseless VT and control of hemodynamically challenging PVCs; Class IIb for stable VT. Dosing, if used in VF is 1.0-1.5mg/kg with repeat dose of half initial dose every 3-5 minutes (total of 3mg/kg/hr). continued reminder that patients over 70 years old should receive half of the recommended repeat doses (half of half dose). Lidocaine is “acceptable” though “its efficacy  is poor and methodologically weak;’ it is now considered a “second tier” agent—“other drugs are preferred over lidocaine in each VT scenario.” Procainamide and sotalol are more effective in VT. 

Magnesium—no routine use; consider in hypomagnesic conditions and torsades de pointes. Emergent administration is “1-2 grams is diluted in 100ml given over 1-2 minutes.” 

Procainamide-routinely given at 20 mg/min, in critical situations may be given up to 50 mg/min. End points remain the same. Is Class IIa in managing AF and atrial flutter, IIb for preexcitation atrial arrhythmias and wide complex tachycardias of unclear origin. 

Sotalol-for use in supraventircular and ventricular arrhythmias; IV dose 1.0-1.5 mg/kg at 10 mg/min. Oral form only available in US currently.

Disopyramide, Flecainide, Ibutilide, propafenone-antiarrhythmics with unclear practicality  and efficacy, particularly in compromised circulatory conditions. 

Epinephrine-…”there is a paucity of evidence to show that it improves outcome in humans.” Concerns raised about creating “severe toxic hyperadrenergic” state, increased myocardial dysfunction, and correct dosing persist. Can be given via ET tube. High dose not recommended for routine use if 1mg doses are ineffective (Class Indeterminate. “Interpretation: acceptable but not recommended.”) but also listed as Class IIb: “acceptable but not recommended; weak supporting evidence”). Dosing in cardiac arrest remains the same, with a reminder that an infusion can be set up to deliver the equivalent of 1 mg every 3-5 minutes (though set up is wrong in Guidelines 2000 supplement pg I-130). Dosing for symptomatic bradycardia is the same (2-10mcg/min) but initial dose is 1mcg/min. 

Vasopressin—directly stimulates smooth muscle receptors causing vasoconstriction. Can be used as an alternative to epinephrine in initial pharmacological management of VF (“Class IIb: acceptable; fair supporting evidence”), may be beneficial for asystole and PEA but sufficient data is lacking (Class Indeterminate: not recommended; not forbidden); insufficient data also to recommend using vasopressin after using epinephrine. Dose, given once, is 40 units (same dose can be given intraosseously) with half-life (animal models) of 10-20 minutes. 

Norepinephrine-no changes, still recommended for use with severe hypotension (systolic less than 70mmHg) and low peripheral resistance. 

Dobutamine—recommended use remains unchanged (“severe systolic heart failure”). Dose range is 5-20 mcg/kg/min. 

Amrinone/milrinone---inotropic and vasodilatory properties (similar to dobutamine) for use in heart fialure and cardiogenic shock. 

Calcium---remains Class III except for specific indications (Class IIb for hyperkalemia, hypocalcemia, calcium channel blocker toxicity). 

Digitalis—effective, but other agents preferred for initial management of atrial fibrillation. 

Nitroglycerin—no significant changes in indications or dosing. 

Sodium nitroprusside—vasodilator for severe heart failure  and hypertensive emergencies. In MI patients, nitroglycerin is preferred with this agent used if nitroglycerin is ineffective. 

Sodium bicarbonate—laboratory and clinical data do not support routine use. No changes in indication or dosage. 

Periarrest conditions—acute coronary syndromes, acute pulmonary edema, hypotension, and shock, symptomatic bradycardias, stable and unstable tachycardias, acute ischemic stroke, impairments of rate, rhythm, cardiac function in post-resuscitation period. 

Review compares a good resuscitation team with a symphony orchestra

Team should

• Keep room quiet so orders and information can be heard easily
• State vital signs every 5 minutes or with any changes
• State medications and procedures when completed
• Request clarification of any orders
• Provide assessment information
• Actively seek suggestions
• Post-code critique and debriefing

Family presence in resuscitation area encouraged at appropriate times with appropriate personnel

DNR vs DNAR—should use do not attempt resuscitation vs. do not resuscitate—the latter implies likelihood of successful outcome if done

Algorithms-observational boxes curved corners, action boxes have squared corners

1998 European Resuscitation council and several ILCOR councils dropped specific reference to pulse check and replaced it ‘check for signs of life’ such as ‘any movement, such as swallowing or breathing’…

ILCOR universal/international algorithm

Assessment (ABCD) then secure airway IV placement and epi or vasopressin given, consider causes:

5H 5T hypovolemia, hypoxia, hydrogen ion (acidosis), hyer/hypokalemia (or other metabolic), hypothermia, tablets (drug OD, accidents), tamponade (cardiac), tension pneumothorax, thrombosis (coronary), thrombosis (pulmonary)

ECC Comprehensive Algorithm

Activate EMS, call for defibrillator, airway, breathing, circulation, defibrillator/monitor attached,

Attempt to place airway device, confirm placement and begin breathing with O2, access circulation via IV and give appropriate agents, differential diagnosis 

Instead of 4 cardiac arrest treatments initially consider simply VT/VF or non-VT/VF—all four get same 4 treatments—CPR, ET intubation, vasoconstrictors, antiarrhythmics (VT/VF shocks are only initial difference) 

Diminishing role of pharmacology in arrest management

Antiarrhythmics may be proarrhythmics 

Pulseless VT/VF algorithm

Initial defibrillations, splace and confirm ETT with physical exam and at least one secondary confirmation device, initiate and IV, give standard dose epi or 40u vasopressin, 300mg amiodarone, consider 1.5 mg/kg lidocaine (if used, a single dose is acceptable or can reach previous max.), 1-2 grams magnesium sulfate (if specific indication), procainamide (30 mg/min) “is acceptable but not recommended because of prolonged administration time…”  Provide defibrillation every  minute or so.

PEA –essentially unchanged; 

Asystole---essentially unchanged; 

Bradycardia—essentially unchanged (isuproterenol no longer on algorithm) though it is cited in literature;

Tachycardia—new emphasis on making a specific rhythm interpretation, recognizing which patients have significantly impaired LV function (usually less than 40%). There are several algorithms and tables in the tachycardia recognition and treatment area.

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