Defibrillation is the treatment for ventricular fibrillation. The success of resuscitation of patients with ventricular fibrillation relates to how quickly electrical energy can be applied to the myocardium. The longer the heart fibrillates, the greater the myocardial oxygen consumption and deterioration of myocardial function. The chance of successful defibrillation is reduced as the fibrillation time increases.

Equipment Required:

  • Zoll biphasic defibrillator
  • Gel pads
  • Life saving drugs (epinephrine, amiodarone, lidocaine).
  • PPE- non-sterile gloves, gown and facemask with shield (assess risk for need of gown and facemask with shield)

  1. Identify life-threatening rhythm
  2. Activate Code Blue
  3. Hand Hygiene and PPE
  4. Initiate CPR
  5. Prepares for defibrillation
  6. Prepare defibrillator
  7. Maintain Environmental Safety environment
  8. Discharge paddles
  9. Continue CPR

  1. Reassess rhythm
  2. Administer epinephrine
  3. Consider cause for non-responsiveness
  4. Administer amiodarone
  5. Return to #8-9
  6. Obstetrical ACLS
  7. Document
  8. Order requirements




Identify Life-Threatening Rhythm

The nurse identifies a life-threatening arrhythmia that requires defibrillation:

  • Ventricular Fibrillation (VF)
  • Pulseless Ventricular tachycardia (VT)

Note: Arterial line pressures < 60 mmHg may be associated with pulselessness.


Successful conversation of these rhythms occurs with rapid delivery of the first shock of energy.

Pulseless VT is often short-lived and deteriorates to VF.


Activate Code Blue

Call a code blue. Notify the critical care physician STAT.


Advanced cardiac life support is required with extra personnel to assist with airway and circulatory interventions.


Hand Hygiene and PPE

Attempt to maintain LHSC Hand Hygiene and Infection Control Policies.  In the event that breaks in technique occur during life-saving resuscitation efforts, communicatethe breaks in technque to the MRP (e.g., inadequate skin prep during emergency line insertion is an indication for elective replacement following stabilization).

Assess personal risk and don appropriate PPE, including gloves, gown and face mask with shield. Personal protection remains a priority.

In the event of any staff exposure, immediately decontaminate area (e.g.., bleed a puncture, wash area or irrigate exposed area), notify leader and following Occupational Health and Safety policies.


In accordance with the MoHLTC 4 moments of hand hygiene and LHSC infection control policies in an effort to reduce risk of transmission of microorganisms and secretions.

It is important to perform a risk assessment and prioritize your own need for protection as indicated.  Your continued ability to support and care for patients depends upon maintaining your own health.


Initiate CPR

The first responder initiates CPR until the defibrillator arrives. Perform chest compressions at a rate of 100/minute to depth of 1/3 to 1/2 the chest wall diameter.


CPR maintains oxygenation and circulation to the brain and heart.


Prepare Patient for Defibrillation

Second responder prepares patient for defibrillation:

  • Side rails down
  • Bed and patient flat
  • Chest exposed
  • Apply gel pads in correct position:
    • One pad on upper chest, below the right clavicle. The second pad below the left nipple at the midaxillary line (see diagram).
    • Ensure paddles have no contact with metal jewelry, nitroglycerin patches or transparent dressings.


Gel pads protect the patient against burns and enhance contact.

Arcing will occur if shock is delivered too close to electrodes.


Prepare Defibrillator:

  1. Continue CPR while preparing defibrillator.
  2. Turn Defibrillator on and ensure dial is set to "Defib".
  3. Ensure the charge is 200 joules.
  4. Charge paddles before placing paddles to chest. The paddles can be charged using the "Charge" button on the paddle or on the front of the monitor
  5. Press paddles firmly to the chest.

Ensure the paddles do not come in contact with ECG leads.


The only treatment for fibrillation is delivering electrical current immediately to the myocardium. Biphasic defibrillators are more successful at converting VF with the first shock.

4. Charge paddles before placing on chest to avoid disruption in CPR.


Maintain Environment Safety

Ensure that there is no contact with any metal objects and no one is in contact with the patient or bed. Call "All Clear".


To ensure patient and team member safety.


Deliver Shock/Discharge paddles

Press paddles firmly onto the gel pads, applying 25-30 lbs of pressure.

Discharge energy by simultaneously depressing the SHOCK button on the paddles or monitor (second person).

Deliver shock following exhalation.



Pressure of 25-30 lbs decreases thoracic impedance and promotes optimum delivery of current.

Air filled lungs decrease electrical conduction. Patient may be in a respiratory arrest.


Continue CPR

  • Do not check for pulse. Immediately return to CPR for 2 minutes (5 cycles of 30:2 compression:ventilation ratios for non intubated patient).
  • If patient is intubated, continue with manual bagging of 8-10 breaths per minute. DO NOT STOP COMPRESSIONS.
  • Charge paddles to 200 Joules before 2 minutes of CPR is completed.



CPR immediately after shock provides myocardial oxygenation which improves shock success.
Higher respiratory rates increase intrathoracic pressure which decreases perfusion of organs.

Paddles charged and ready will prevent interruption to CPR.


Reassess Rhythm

  • Quickly reassess rhythm to ensure that conversion of VF/VT has not occurred.
  • Proceed to deliver the next shock as in #7 at
    200 J.
  • Energy can be increased by using the + button on the paddle or up arrow on the front of the monitor.
  • Repeat CPR as in #8 after pulse and rhythm check.



Ensure energy not being delivered to converted rhythm.


Administer Epinephrine

While CPR is being performed, administer epinephrine 1 mg IV direct per defibrillation procedure under medical directive.



Epinephrine can increase cerebral and coronary perfusion pressures by alpha vasoconstriction.
Delivery of drug during compressions minimizes interruptions to CPR.


Consider Causes for Non-responsiveness

Return to step # 8-9.
Troubleshoot for possible causes of non-responsive VT/VF (e.g. electrolyte disturbance, hypoxemia, MI).



To treat other correctable causes.

Consider H's and T's



Hydrogen ions





Tension pneumothorax

Thrombosis: coronary/pulmonary

Consider adrenal endocrine (adrenal insufficiency, hypoglycemia)


Administer Antiarrhythmic

While CPR is being performed, administer amiodarone 300 mg IV direct per defibrillation procedure.

If contraindicated, administer lidocaine 1 mg/kg per defibrillation procedure under medical directive.

Start infusion of antiarrhythmic if successful per the defibrillationprocedure under medical directive.


Antiarrhythmics, in conjunction with defibrillation, may convert life-threatening arrhythmias.

Delivery of drug during compressions minimizes interruptions to CPR.


Return to Steps 8-10

Maintain ABC’s.
Continue to treat possible causes of arrhythmia.

Return to Step #11 Administer Epinenphrine

Continue CPR as per step # 9 followed then by step # 10.




Repeat epinephrine q 3 minutes. A physicians order is required after 2nd dose.


Obstetrical Considerations

The priority during resuscitation of the pregnant patient is the mother.

Follow standard ACLS and medication administration with the following modifications:

  • Hand position slightly cephalic (closer to patient's head)
  • Perform CPR in the supine position with one person assigned to manually display the uterus toward the patient's left (use two hand utterine "pull technique if standing on patient's left side or one hand "push" if standing on patients right side.
  • IV above the diaphragm
  • Consider calcium chloride if patient was receiving magnesium sulphate
  • Activate Code OB STAT (VH site only); goal is perimortem C-section within 4 minutes of cardiac arrest




This skill delegates to ordering authority to RNs in critical care.


Causes for Maternal Cardiac Arrest (Beauchops)

B     Bleeding/DIC

E     Embolism cardiac/pulmonary/ amniotic

A    Anaesthetic complications

   Uterine atony

C    Cardiac disease: MI/ischemia/aortic dissection/cardiomyopathy


   Review standard ACLS guidelines (Hs and Ts)

   Placental abruptio, previa

S    Sepsis




Document in cardiac arrest record.


Nurses in critical care have been granted teh authority to initiate ACLS.


Order Requirements

The medical directive for ACLS provides teh authority to initiate interventions.

The RN who initiates the medical directive should be identified in the cardiac arrest record.  For delegated orders that are initiated after completion of the Cardiac Arrest Records, orders should be entered electronically with the communication type identified as "Medical Directive" (e.g., initiation of amiodarone infusion).

Medications given outside of the Cardiac Arrest Record must be signed in the electronic Medication Administration Record (MAR).  Back charting is appropriate during a resuscitation event.




This skill delegates to ordering authority to RNs in critical care.




American Heart Association. (2015). Highlights of the 2015 AHA Guidelines Update for CPR and ECC.

American Heart Association (2015). Part 7. Adult Advanced Cardiac Life Support.

American Heart Association (2015). Part 10. Special Circumstances of Resuscitatation.

Developed by:
Judy Hackett RN BScN CCTC
Clinical Educator, CCTC
August 14, 2006

Last Update: October 16, 2017 (BM)

LHSCHealth Professionals

Last Updated October 16, 2017 | © 2007, LHSC, London Ontario Canada