• The purpose of defibrillation is to terminate VF/pVT by passing an electrical current across the heart to depolarise a critical mass of myocardial cells.

• Defibrillation is more likely to be successful if:

  • Time from collapse to shock is minimised.

  • The collapse has been witnessed and the patient has received bystander CPR.

  • BLS is of good quality (correct rate and depth, complete chest recoil, minimal interruptions and maximal chest compression fraction).

  • The pre-shock pause is as short as possible (< 5 secs).

  • The defibrillation pads are placed correctly.

• Minimise pre-shock pauses, by resuming chest compressions immediately after the rhythm check while the defibrillator charges. It is also acceptable to charge the defibrillator as the end of the 2 minutes of CPR approaches while continuing chest compressions. All team members should stand clear for the rhythm check so that the shock can be delivered without delay if appropriate, before immediately resuming CPR.

• A range of defibrillation energy levels have been recommended ranging from 120–360 J. Starting with an initial shock no greater than 150 J, increasing each time up to 360 J.

• Delivering the first shock as soon as possible is the priority. Therefore, when attending as a solo responder equipped with a defibrillator, immediate assessment of the rhythm and defibrillation (when indicated) should take precedence over airway or breathing interventions. If possible, use a bystander to start and continue chest compressions while the defibrillator is attached. Although defibrillation is an initial priority, it is important to minimise delays and interruptions in delivering chest compressions. 

• The initial approach to airway management should usually be BVM. An oropharyngeal airway (OPA) or nasopharyngeal airway (NPA) may be used to improve the efficacy of ventilations via the BVM.

• An iGel is the gold standard airway without critical care! It sits above the larynx and is simpler and quicker to insert than a tracheal tube. They can be inserted with minimal interruption to chest compressions.

• There is no evidence that patient outcome is any better following tracheal intubation compared with any other type of airway.

• When tracheal intubation is undertaken, the availability of a bougie and the use of waveform capnography is mandatory.

• Visualisation of the tube entering the trachea, auscultation over both axillae and epigastrium, and observation of chest wall movement should all aid confirmation but are not in themselves 100% diagnostic of correct tube placement. This can only be achieved by using waveform capnography.

Bag-mask Ventilation (BVM)

• The initial approach to airway management should usually be BVM. An oropharyngeal airway (OPA) or nasopharyngeal airway (NPA) may be used to improve the efficacy of ventilations via the BVM.

• A complication of ventilation with a BVM is gastric inflation, resulting in impaired ventilation and regurgitation, especially where forceful ventilations are delivered. This risk is reduced where gentle ventilations are delivered over 1 second or where an SGA is used. As such, it is reasonable to place a suitable SGA as part of BLS, when trained in its use.

Supraglottic Airways

• There are several SGAs (e.g. iGel and laryngeal mask airway); all sit above the larynx, and are simpler and quicker to insert than a tracheal tube. They can be inserted with minimal interruption to chest compressions.

• A number of case reports exist describing patients who have been found to have foreign bodies deep within their oropharynx. It is therefore recommended that if there is a high degree of suspicion of foreign body airway obstruction, inspection of the oropharynx should be undertaken with a laryngoscope before inserting any SGA.

• Once an SGA has been placed, continuous chest compressions with 10 ventilations per minute are preferred. However, 30 compressions to two ventilations are acceptable if ventilation is inadequate when delivering continuous compressions.

• Waveform capnography should always be used when using a supraglottic device and BVM.

• Air leaks from around the SGA are common. If the chest wall can be seen to be moving, ventilation is generally adequate. However, repositioning orreplacement of the airway with a more suitable size may be necessary if the air leak is of sufficient magnitude to prevent the chest rising and falling with each breath.

Tracheal Intubation (Critical Care Practitioners)

• The tracheal tube is a challenging airway device to insert successfully and requires both adequate initial training and ongoing practice. Paramedics must ensure that they have appropriate competence to undertake it safely and that this skill has been regularly updated and evidenced through maintaining an airway skills log.

• There is no evidence that patient outcome is any better following tracheal intubation compared with any other type of airway.

• When tracheal intubation is undertaken, the availability of a bougie and use of waveform capnography is mandatory.

• Visualisation of the tube entering the trachea, auscultation over both axillae and epigastrium, and observation of chest wall movement should all aid confirmation but are not in themselves 100% diagnostic of correct tube placement. This can only be achieved by using waveform capnography.

• If the capnography trace is flat (or only shows minimal baseline fluctuation), then it must be assumed that the tracheal tube is sited incorrectly and must be removed.

• Once a tracheal tube is in place, continue continuous chest compressions with 10 gentle ventilations per minute. Avoid hyperventilation and high airway pressures during manual ventilation which adversely affect outcome.

• It is important to remember the following for tracheal intubation:

• Ensure 360° access around the patient where possible. (This may involve rapidly moving the patient to give better access.)

• Prepare a kit dump of all the necessary equipment close to the patient before starting the process of intubation. This must include suction, a bougie and immediate access to capnography monitoring and any additional airway equipment necessary for a failed intubation.

• Do not routinely use cricoid pressure for tracheal intubation during CPR.

• If during laryngoscopy the paramedic needs a better view, use external laryngeal manipulation. Pressure directed to move the trachea backwards, upwards and to the right (BURP manoeuvre) may improve visualisation of the vocal cords.

• Secure the tracheal tube immediately after insertion, noting length at incisors. This is approximately:

  • adult males: 22–24 cm

  • adult females: 21–23 cm.

• Listen to any team member who suggests that the attempt has become a ‘Can’t intubate, can’t ventilate scenario’, irrespective of clinical grade.

• Avoid hypoxaemia during intubation: pre-oxygenate the lungs before and between intubation attempts.

• Where possible, use two team members to attempt intubation, and ensure a failed intubation plan has been communicated to all the team.

Capnography

• Capnography (measurement of exhaled (end-tidal) carbon dioxide ‒ EtCO2) assists in confirmation and continuous monitoring of tracheal tube placement, can provide feedback on the quality of CPR and can provide an early ROSC.

• Waveform capnography is a real-time waveform display of EtCO2 and is more accurate and reliable than a paper indicator.

• The use of waveform capnography is mandatory in paramedic intubation. Tracheal intubation and subsequent monitoring must only be performed with the assistance of waveform capnography monitoring. Recorded values must be documented on the patient record at 5-minute intervals. In the absence of waveform capnography, an alternative airway technique or device should be employed.

• Any decision to terminate resuscitation should not be based on either the presence or absence of EtCO2 alone.

• Waveform capnography is recommended where an SGA has been placed, as it is useful in providing positive feedback on the quality of CPR.

• Hypothermia: A state of abnormally low body temperature.

  • Warm the patient, 1 degree per hour, double cardiac arrest drug intervals, time-critical transfer to the nearest ED

• Hypoxia: Inadequate oxygen supply to body tissues.

  • Provide 100% oxygen via a BVM with a maintained airway

• Hypovolemia: Decreased blood volume or fluid loss.

  • IV/IO Fluids, Blood Products (HEMS), Stop any bleeding

  • Consider time-critical transfer to trauma unit/major trauma centre

• Hyper and Hypo metabolic disorders: Abnormalities in metabolic rate, either excessive or insufficient.

  • Check blood sugars, give 10% Glucose IV if below 4 mmol

• Tension pneumothorax: The accumulation of air in the pleural space, causing lung collapse and increased pressure on the heart.

  • Are there decreased breath sounds or decreased rise and fall?

  • Lateral or Bilateral chest decompression

  • Thoracostomy 

  • Consider time-critical transfer to trauma unit/major trauma centre

• Cardiac Tamponade: The compression of the heart due to the accumulation of fluid or blood in the pericardial sac.

  • CRITICAL CARE - Confirm with Ultrasound, and do a pericardiocentesis

  • Consider time-critical transfer to trauma unit/major trauma centre

• Toxins: Harmful substances that can adversely affect bodily functions and systems.

  • Opioid Overdose? Naloxone?

  • Are other toxins present? Can it be reversed?

  • Consider early transport to receiving ED for further management.

• Thrombus: A blood clot that obstructs blood flow within a blood vessel.

  • Identify the potential cause (Stroke, Heart Attack etc)

  • Transfer to the receiving facility

HOTT Approach (Traumatic Cardiac Arrest)

• Hypovolemia: Decreased blood volume or fluid loss.

  • IV/IO Fluids, Blood Products (HEMS), Stop any bleeding

  • Consider time-critical transfer to trauma unit/major trauma centre

• Oxygenation: Give 100% Oxygen via a BVM with a maintained airway.

• Cardiac Tamponade: The compression of the heart due to the accumulation of fluid or blood in the pericardial sac.

  • CRITICAL CARE - Confirm with Ultrasound, and do a pericardiocentesis

  • Consider time-critical transfer to trauma unit/major trauma centre

• Tension pneumothorax: The accumulation of air in the pleural space, causing lung collapse and increased pressure on the heart.

  • All traumatic cardiac arrests require bilateral needle chest decompression as soon as possible.

  • Are there decreased breath sounds or decreased rise and fall?

  • Lateral or Bilateral chest decompression

  • Thoracostomy?

  • Consider time-critical transfer to trauma unit/major trauma centre