Advanced Cardiac Life Support

last authored: April 2010, David LaPierre
last reviewed:

 

 

Introduction

Advanced cardiac life support (ACLS) describes the treatment of life-threatening cardiac rhythms. ACLS may only be provided by trained experts, as it includes advanced ECG diagnostics, procedural skills, and use of medications. It builds upon basic life support, or CPR, and the use of automated external defibrillators (AEDs). Both these can be used by trained members of the public.

 

Many health care professionals require ongoing certification. ACLS is taught in the US by the American Heart Association, in Europe, by the European Resuscitation Council (ERC). Training is usually completed with simulations and a dummy, though sofware can also be used.

 

The 2005 guidelines acknowledged that high quality chest compressions and early defibrillation were the key to positive outcomes while other "typical ACLS therapies ... "have not been shown to increase rate of survival to hospital discharge".[2] In 2004 a study found that the basic interventions of CPR and early defibrillation and not the advanced support improved survival from cardiac arrest.

 

 

 

 

ACLS Survey

ACLS begins with BLS, and an assessment of a patient's airway, breathing, and circulation. At each step, it is important to act before continuing. Shocks are provided according to montior and vital signs, not in in response to an AED's evaluation.

 

A secondary survey should be quickly done to identify possible causes of cardiac arrest (e.g., a heart attack, drug overdose, or trauma).

 

Throughout ACLS, it is critical to continue chest compression with minimal interruptions.

ACLS survey is often done by many team members, and should be on an ongoing basis throughout ACLS response.

 

Airway

Is the airway open?

Does the patient need an advanced airway?

 

 

Breathing

Is oxygenation and ventilation sufficient?

If used, is the airway device properly placed and monitored?

Are CO2 and O2 sats being monitored?

 

 

Circulation

What is the current cardiac rhythm?

Is IV/IO access obtained?

Does the patient need fluids or medications?

 

Differential Diagnosis

Why did arrest occur? Are there any other factors?

Can we reverse the cause(s)?

7 H's and 5 T's: mnemonic for mechanisms

  • hypoxia
  • hypovolemia
  • hyperkalemia
  • hypokalemia
  • hypoglycemia
  • hypothermia
  • hydrogen ions (acidosis)
  • thrombosis (MI)
  • tension pneumothorax
  • tamponade
  • toxins/therapeutics
  • thromboembolism
  • trauma

 

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Procedures and Medications Used

There are many procedures that may be required during ACLS. These normally include insertion of intravenous (IV) lines and placement of various airway devices. Commonly used ACLS drugs, such as epinephrine, atropine and amiodarone, are then administered.

  • airway devices
  • vascular access and fluids
  • medications
  • monitoring
  • defibrillation
  • other

Airway Devices

Both basic and advanced airways may be used during ACLS.

 

Vascular Access and Fluids

 

Vascular access is a priority during ACLS, allowing medications and fluids to be rapidly given. Options include:

  • peripheral venous access
  • intra-osseous access
  • central line access: usually unnecessary, and may cause many complications during recuscitation
  • endotraceal access: not preferred. Doses are unknown, but are typically 2-2.5 x the IV dose.
    • may give epinephrine, vasopressin, atropine, lidocaine, naloxone.

Medications

Medication administration is of secondary importance. While vasopressors and inotropes do appear to assist with spontaneous return of circulation, they have not been shown to improve survial to hospital discharge (ref). When medications are given intravenously, give drug, follow by 20ml fluid bolus, and elevate limb for 10-20 seconds. A drug typically takes 1-2 minutes to reach the central circulation, or once cycle of CPR.

 

See vasopressors and inotropes for further information on specific drugs.

Monitoring

Defibrillation

 

After the first shock, immediately resume CPR, givng 5 cycles.

Other

chest tube

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Effective Team Functioning

There are a number of roles that are important for running resuscitations:

It is important that the team leader be responsible for assigning roles and ensuring team members are functioning effectively.

 

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Clinical Scenarios

Always assess, then reassess the patient on an ongoing basis.

  • respiratory
    arrest
  • pulseless VT
    and VF
  • pulseless electrical
    activity and asystole
  • acute coronary
    syndromes
  • bradycardia

  • tachycardia

  • SVT

  • stroke

Respiratory Arrest

In respiratory arrest, a pulse is present, though breathing is absent or ineffective.

Perform BLS.

Give one breath every 5-6 seconds, or 10-12 per minute.

Check pulse (quickly) every two minutes.

 

Airway

Consider placement of airway devices:

  • oropharyngeal airway
  • nasopharyngeal airway
  • laryngeal mask airway
  • endotracheal tube
  • esophageal-tracheal Combitube

suction as needed

 

Difficult airways:

Supraglottic device

  • MOODS
  • mouth open

Four cornerstones of airway management

  • bag-valve-mask
  • laryngoscopy and intubation
  • cricothyroidotomy
  • supraglottic device

 

Breathing

monitor oxygen and provide supplemental oxygen as appropriate

Confirm proper placement, secure, and reassess frequently.

  • Obtain IV/IO access
  • attach ECG leads
  • give fluids and medications as appropriate

Pulseless Ventricular Tachycardia and Ventricular Fibrillation

With sudden cardiac arrest, the most common initial rhythms are pulseless ventricular tachycardia (VT) and ventricular fibrillation (VF). VT will rapidly lead to VF, which will become asystole unless defibrillation is quickly given.

 

Ventricular fibrillation is the chaotic contraction of the heart, leading to a lack of perfusion and loss of consciousness. It is rapidly fatal without intervention.

 

If witnessed, a single precordial thump may be given, followed by CPR.

 

AED

Begin with the basic life support (BLS) primary survey: ABCD

Perform high-quality CPR until an AED arrives. Early defibrillation is critical to increase chances of survival.

 

 

Inside hospital

Call for help, activating 'code blue' and asking for the crash cart.

 

Begin with CPR, giving oxygen as available. Establish IV access, if not already obtained.

 

Once the crash cart arrives, connect the leads to the ECG monitor and defibrillator. If skills are sufficient, AED should not be used, as it leads to unnecessary delays.

 

The team leader will coordinate efforts.

 

Perform high-quality CPR and ventilations at a ratio of 30:2 compressions:breaths. Pause chest compressions only for ventilation without advanced airway, for rhythm checks, and for shock delivery.

 

Newer defibrillators charge rapidly, under 10 seconds. If this is the case, compressions may be paused during charge. If the charge time is longer than 10 seconds, continue compressions until shock is ready.

 

New guidelines suggest one shock, with voltage depending on type of defibrillator:

  • manual biphasic: device specific 120-200 J
  • monophasic: 360 J

Warn others firmly that a shock is imminent, and ensure all providers are clear.

 

Immediately begin 5 cycles of CPR (2 minutes) before stopping for rhythm check. If rhythm is shockable, give shock, and immediately resume CPR.

 

When IV/IO access is obtained, give vasopressor:

  • epinephrine 1mg IV/IO, repeat every 3-5 minutes
  • vasopressin 40 U IV/IO, may be given once

Immediately begin 5 cycles of CPR (2 minutes) before stopping for rhythm check. If rhythm is shockable, give shock, and immediately resume CPR.

 

Consider antiarrhythmics:

  • amiodarone (300mg IV push, then 150mg IV push)
  • lidocaine (100mg IV push, then 50 mg IV push)
  • magnesium sulfate (1-2g over 1 min, IV push)

 

If the montor shows a non-shockable, orgainized rhythm, do a pulse check. If pulse is present, begin post-resuscitation care.

 

Hypothermia will be addressed elsewhere.

 

Once perfusing rhythm has started, consider providing an antiarrhythmic (i.e., amiodarone or lidocaine) for maintenance therapy. It is usual to choose the drug used during recuscitation.

Pulseless Electrical Activity and Systole

 

In pulseless electrical activity (PEA), the target of intervention is the cause, not the rhythm. With PEA, it is imparative to provide quality care and to work hard to identify reversible causes. Both PEA and asystole are treated the same.

 

Inside hospital

Begin with CPR, giving oxygen as available, until ECG monitor and defibrillator arrives with a code team. During rhythm and pulse check, if PEA or asystole are identified, resume CPR immediately. Consider H's and T's, as above. Obtain a 12-lead ECG, which can provide clues as to the cause.

 

IV/IO access is a priority over advanced airway placement.

Vasopressors should be given once IV/IO access is in place. This includes:

  • epinehprine 1 mg IV/IO, repeated every 3-5 minutes
  • vasopressin 40 U may be given once in place of a dose of epinephrine

Consider atropine 1 mg IV/IO for asystole or slow PEA; repeat every 3-5 minutes, to a maximum of 3 doses. Atropine is not recommended in the Heart and Stroke Foundation of Canada's 2010 guidelines.

 

Do rhythm/pulse checks every 2 minutes after administration of a drug.

  • if a shockable rhythm is present, shock, according to the VT/VF algorithm
  • if pulse is present, begin post-recuscitative care
  • if no shockable rhythm is present, continue CPR and vasopressor/atropine administration.

With systole, ensure equipment is not responsible for the flat line, and that the rhythm is not fine VF.

 

Recuscitation should be avoided in victims with

  • DNAR status
  • living will
  • rigor mortis
  • dangerous circumstances

Acute Coronary Syndromes

Algorithms for acute coronary syndromes covered elsewhere.

Bradycardia

There are many causes of bradycardia, including sinus bradycardia and heart blocks.

 

Identification of a bradycardia should lead to primary survey of the ABC's, intervening as necessary. Oxygen is recommended. Monitor ECG, blood pressure, and oxygen saturation.

 

Decision to treat depend on perfusion; if adequate, monitoring is sufficient. If perfusion is poor, however, treatment should be instituted.

 

If type II, second-degree or third degree heart block is present, prepare immediately for transcutaneous pacing. Consider atropine 0.5 mg IV while waiting, repeating up to a maximum of 3 mg. Consider epinephrine (2-10 mcg/min) or dopamine (2-10 mcg/kg/min) infusion while waiting.

 

Transcutaneous pacing may be painful and will require procedural sedation, potentially further compromising hemodynamics. However, in unstable patients, proceed immediately.

 

Treat with TCP with the goal of improving clinical symptoms. If acute coronary syndrome is present, maintain pacing at the lowest current required.

 

Ventricular Tachycardia

Tachycardia can be caused by a number of conditions. A key question is whether the patient has a pulse; if not, proceed with BLS. If pulses are present, determine whether patient is stable or unstable, and provide treatment accordingly.

 

stable tachycardia

With stable ventricular tachycardia, provide:

  • oxygen
  • lidocaine 1-1.5 mg/kg q 5-10 min, with repeat doses at 0.5 mg/kg (max 3mg/kg total)
  • procainamide (20mg/min; max 17mg/kg)
  • amiodarone (150mg over 10 min for loading, then 1mg/min x 6 hours and then 0.5mg/min for 18 hours)

 

unstable tachycardia

Unstable tachycardia occurs when the rate is so fast (often above 150/min), or so uncoordinated, that cardiac output drops. This can lead to cardiac, cerebral, and renal ischemia, and to pulmonary edema. In the ill or frail, lower heart rates can lead to instability.

 

Signs and symptoms can include:

  • chest pain
  • shortness of breath
  • altered, decreased, or loss of consciousness
  • weakness or fatigue
  • hypotension
  • ECG signs of ischemia
  • pulomary edema
  • poor peripheral perfusion

It is important to determine whether signs and symptoms are due to tachycardia, or whether the tachycardia and signs and symptoms are due to another condition (e.g., myocardial infarction). In general, a rate between 100-130/min suggests an underlying process.

 

cardioversion is the treatment for unstable tachycardia. Consider sedation with fentanyl or midazolam, being attentive to blood pressure.

Cardiovert at increasing dosages: 100J, 200J, 300J, 360J

Provide lidocaine at 1-1.5mg/kg

Supraventricular tachycardia

A SVT has a narrow QRS.

Establish IV access.

Stable

A stable patient is a symptomatic.

The following maneuvers may be considered:

  • vagal maneuvers
  • carotid massage (if risk of atherosclerosis is low)
  • adenosine 6mg IV push, then 12mg IV push
  • diltiazem 20mg bolus IV over 1-2 min, followed by infusion (5mg/hr)
  • consider digoxin 0.25 IV push

unstable

Consider sedation.

Cardiovert at 100J, then 200J, then 300J, then 360J.

Stroke

Stroke treatment will be covered elsewhere.

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Stopping Recuscitation

Each patient case is unique, and while clinical rules are developed, the decision to stop CPR is a complex one. Except in specific circumstances, such as hypothermia or drug overdose, BLS or ACLS are very unlikely to be successful after 20 minutes.

 

In hospital, the decision is based upon:

Outside hospital, CPR should be continued until:

 

 

Resources and References

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