Advanced Cardiovascular Life Support (ACLS) is the traditional name for a set of practices adopted by healthcare providers on patients with acute cardiovascular disorders or cardiac arrest. The guidelines are updated periodically (every 5 years or so).
MANAGEMENT OF CARDIAC ARREST:
The pillar of the treatment is the maintenance of good cardiopulmonary resuscitation (CPR) and the defibrillation if the arrhythmia demands it (pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF)). Since the lack of circulation seems to be the most important aspect to treat during a cardiac arrest, the old A-B-C paradigm (airway, breathing and circulation) has been replaced by the C-A-B paradigm (circulation, airway and breathing). This means that good quality CPR and early defibrillation if needed should precede any other time-consuming interventions.
An unconscious patient without pulse or in a clinical stage near cardiac arrest (e.g. gasping) should prompt the activation of an emergency response team – code blue – according to the protocols of the institution.
CPR should be started immediately and, in this mean time, cardiac monitoring should be placed and IV or IO access obtained. Oxygen should be provided and ventilation with bag-mask ventilation (BMV), oral or nasal device should start.
Before going to the specific algorithms that should be followed, some aspects of CPR and ventilation are discussed.
CPR: CPR consists in chest compressions. They must have sufficient depth (5 to 6cm or 2 to 2.5 inches), they must allow the chest to complete recoil between compressions and the ideal rate is around 100-120 per minute. They should not be interrupted for more than 10 seconds (e.g. for intubation or BVM ventilation). PETCO2 <10 mmHg (measured with quantitative waveform capnography) or relaxation phase (diastolic) pressure < 20mmHg (measured with intra-arterial pressure) indicates low quality CPR.
CPR be done in 2 minute blocks. The CPR provider should be switched every 2 minutes to ensure efficacy of compressions. A “cycle” of CPR consists in 30 compressions and 2 breaths (which corresponds to around 5 cycles in 2 minutes) if there is no invasive airway present. If there is an invasive airway, there is no need to correlate ventilation and chest compression rate.
Ventilation: Ventilatory support should be provided ASAP.
If the patient is not intubated (e.g. BMV), the compression to ventilation rate is 30:2. If the patient is intubated, the rate should be a maximum of 6-10 ventilations/min.
During CPR, is reasonable to provide patients with 100% oxygen.
Continuous waveform capnography (performed in addition to clinical assessment) is recommended for both confirming and monitoring correct tracheal tube placement, and for monitoring the quality of CPR and the return of spontaneous circulation.
GENERAL CARDIAC ARREST ALGORITHM:
Establish unresponsiveness and lack of pulse
Call for help/activate EMS/activate emergency response team
Start CPR immediately
Provide ventilation and oxygen if available
After 5 cycles of CPR (2 minutes) the rhythm should be checked. According to the rhythm the following actions should follow:
- Rhythm – Check for pulse. If pulse is present, go to after ROSC care.
- Non-shockable rhythm (PEA or Asystole) AND no pulse – Follow PEA/Asystole algorithm.
- Shockable rhythm (pulseless VT or VF) without a pulse – Defibrillate (follow VF/pulseless VT algorithm).
VENTRICULAR FIBRILLATION (VF) OR VENTRICULAR TACHYCARDIA ALGORITHM:
- Start CPR
- After 2 minutes of CPR the rhythm should be checked if VF or pulseless VT is identified, defibrillation should be given (120-200J on a biphasic defibrillator or 360J on a monophasic defibrillator)
- Continue CPR for 2 minutes
- Consider advanced airway, capnography
- Give epinephrine 1mg q3-5 minutes (vasopressin 40U can be used on the first or second time).
- Check rhythm after 2 minutes or CPR:
Shockable rhythm – Defibrillate and Resume CPR (2min).
Non-shockable rhythm and no pulse – Go to PEA/Asystole algorithm
Rhythm and pulse – Go to after ROSC care
- Give amiodarone (300mg, may be repeated 150mg), continue CPR
- Go to Item 6.
ASYSTOLE OR PULSELESS ELECTRIC ACTIVITY ALGORITHM:
- Start CPR
- Check rhythm after 2 minutes of CPR, if PEA or Asystole, continue CPR for 2 minutes. If other VF/pulseless VT, go to the other algorithm (item 6). If ROSC, go to after ROSC care.
- Continue CPR, Consider advanced airway, capnography
- Give epinephrine 1mg q3-5 minutes.
- After 2 minutes of CPR, check the rhythm. If no shockable rhythm, continue CPR. If other VF/pulseless VT, go to that algorithm (item 6). If ROSC, go to after ROSC care.
- Continue CPR, think about reversible causes and manage accordingly (Hs and Ts).
- Go to item 5.
POSSIBLE CAUSES OF CARDIAC ARREST (Hs and Ts):
Hydrogen ion (acidosis)
Hypo or Hyperkalemia
BRIEF SUMMARY OF DRUGS USED DURING CARDIAC ARREST:
Epinephrine can be given IV/IO/ET. Dose is 1mg q3-5 minutes. (ET dose is 2 to 2.5 times higher)
Vasopressin can be given IV/IO/ET. Dose is 40 units. It can replace the first or second dose of epinephrine. (ET dose is 2 to 2.5 times higher)
Amiodarone can be given IV/IO. First dose is 300mg bolus. Second dose is 150mg.
AFTER RETURN OF SPONTANEOUS CIRCULATION (ROSC):
ROSC is characterized by return of pulse, blood pressure, abrupt sustained increase in PETCO2 (>=40mmHg) and spontaneous arterial pressure waves with intra-arterial monitoring.
Oxygen may be used but hyperoxia should be avoided (minimum Fio2 necessary to keep SatO2 >94%). PETCO2 should be around 35-40mmHg.
IV line should be established (if not previously done).
SBP should be maintained kept > 90mmHg (or MAP >65mmHg). If the patient is hypotensive, 1-2 liters of normal saline may be given (if inducing hypothermia, may use 4 degrees Celsius fluid). If hypotension remains, vasopressors should be used (epinephrine 0.1-0.5 mcg/kg/min; norepinephrine 0.1-0.5 mcg/kg/min; dopamine 2-10 mcg/kg/min).
Figure out the cause of cardiac arrest: Evaluate Hs and Ts for treatable causes of the cardiac arrest.
- Patient follows commands? Obtain an ECG and other relevant testing.
- Patient does not follow command? Consider therapeutic hypothermia (32-36 degrees Celsius for >= 24h followed by gradual rewarming 0.25 degree Celsius/h) and then run ECG. Therapeutic hypothermia is contraindicated in patients with noncompressible bleeding.
ECG shows MI – Transfer to PCI. ECG is negative – Transfer to ICU.
Treat underlying causes.
BASIC BRADYCARDIA ALGORITHM:
Once the clinically relevant bradycardia (HR < 50bpm) is identified:
Maintain airway (IOT + MV if necessary)
Monitor HR, BP and SatO2.
Give oxygen if needed.
Establish IV/IO access.
Try to identify cause (but do not delay treatment).
Obtain 12-lead ECG.
- Stable patient (no hypotension, no chest pain, no altered mental status, no acute HF): Continue observation and investigation for causes.
- Unstable patient (hypotension or shock, altered mental status, chest pain, acute HF): Atropine 0.5mg IV/IO (can be repeated every 3-5 minutes to max. of 3mg) can be used. If atropine is not effective, transcutaneous pacing OR dopamine infusion (2-10 mcg/kg/min) OR epinephrine infusion (IV/IO 2-10 mcg/kg/min) can be used. Consider expert consultation and trans venous pacing.
BASIC TACHYCARDIA ALGORITHM:
Patient has pulse?
No – Start CPR
Yes – Check A-B-C, Monitor HR, BP and SatO2 (keep SatO2> 94%), get an ECG, identify rhythm.
Try to identify cause (but do not delay treatment).
- Stable patient (no hypotension or shock, normal consciousness, no chest pain)
Establish an IV/IO line.
Asses QRS complex (ECG):
Adenosine 6mg bolus (may be given a 12mg second dose and a 12mg third dose). If tachycardia resumes, AV nodal blocking agents (diltiazem or beta-blockers) may be used.
Consider expert consultation. Amiodarone (150 mg IV over 10 minutes, repeat as needed to maximum dose of 2.2g in 24h) may be used. If polymorphic ventricular tachycardia (Torsades de pointes) is present, give magnesium (1-2g over 5-60min load, then infusion).
- Unstable patient (hypotension, shock, decreased consciousness or chest pain):
Establish IV line
Give sedation if conscious
Synchronized cardioversion should be provided using the following energy (J):
50-100J for narrow and regular QRS,
120-200J for narrow and irregular QRS,
100J for wide and regular QRS,
Defibrillation dose for wide irregular QRS (120-200J on a biphasic defibrillator or 360J on a monophasic defibrillator).
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