Atrial Fibrillation (AF) Acute Management ABCDE

Atrial Fibrillation (AF) Acute Management ABCDE

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Overview of Recognition and Immediate Management of Atrial Fibrillation Using an ABCDE Approach

The ABCDE approach can be used to perform a systematic assessment of a critically unwell patient. It involves working through the following steps:

  • Airway
  • Breathing
  • Circulation
  • Disability
  • Exposure

Each stage of the ABCDE approach involves clinical assessment, investigations and interventions. Problems are addressed as they are identified and the patient is re-assessed regularly to monitor their response to treatment.

This guide has been created to assist students in preparing for emergency simulation sessions as part of their training, it is not intended to be relied upon for patient care.


What is Atrial Fibrillation?

Atrial fibrillation (AF) is an atrial tachydysrhythmia where multiple waves of electrical activity compete with each other in the atrium and bombard the atrioventricular node. This results in irregular conduction down the bundle of His and as a result, irregular ventricular contraction. If the ventricular response is rapid, cardiac output can become impaired due to uncoordinated myocardial contraction.

The causes of AF are vast and complex but usually, a patient with AF has an underlying abnormal atrium, both anatomically (dilated) and histologically (fibrotic from inflammation). Patients may suffer from symptoms of AF constantly or intermittently, whilst others may be completely asymptomatic.

What is ‘Fast AF’?

Some patients present with sudden onset of palpitations and breathlessness and are found to be tachycardic in atrial fibrillation. Instead of referring to this presentation as ‘fast AF’, this presentation is more accurately AF with a rapid ventricular response (sometimes written as AF with RVR).

Triggers for AF

There are many conditions that can either trigger the first episode of AF or make pre-existing AF worse. The Royal College of Emergency Medicine has created the PIRATES mnemonic to make memorising AF triggers a little easier:

  • Pulmonary embolism
  • Ischemia
  • Respiratory disease
  • Atrial enlargement or myxoma
  • Thyroid disease
  • Ethanol
  • Sepsis/sleep apnoea

Clinical Features of New-Onset AF


Typical symptoms of new-onset AF include:

  • Palpitations (e.g. pounding in your chest)
  • Dizziness and light-headedness
  • Weakness
  • Breathlessness
  • Chest pain

Atrial Fibrillation (AF)

Atrial fibrillation (AF) is a common arrhythmia, with typical symptoms including:

  • Palpitations (e.g. a sense of fluttering in the chest)
  • Dizziness
  • Shortness of breath
  • Anxiety
  • Chest pain

Clinical signs

Typical clinical signs of AF include:

  • An irregularly irregular pulse
  • Tachycardia (if AF with rapid ventricular response)

Tips before you begin

General tips for applying an ABCDE approach in an emergency setting include:

  • Treat all problems as you discover them.
  • Re-assess regularly and after every intervention to monitor a patient's response to treatment.
  • Make use of the team around you by delegating tasks where appropriate.
  • All critically unwell patients should have continuous monitoring equipment attached for accurate observations.
  • Clearly communicate how often would you like the patient's observations relayed to you by other staff members.
  • If you require senior input, call for help early using an appropriate SBARR handover structure.
  • Review results as they become available (e.g. laboratory investigations).
  • Make use of your local guidelines and algorithms in managing specific scenarios.
  • Any medications or fluids will need to be prescribed at the time (in some cases you may be able to delegate this to another member of staff).
  • Your assessment and management should be documented clearly in the notes, however, this should not delay initial clinical assessment, investigations and interventions.

Initial steps

Acute scenarios typically begin with a brief handover from a member of the nursing staff including the patient's name, age, background and the reason the review has been requested.

You may be asked to review a patient with AF due to palpitations, chest pain and/or dizziness.


Introduce yourself to whoever has requested a review of the patient and listen carefully to their handover.


Introduce yourself to the patient including your name and role.

Ask how the patient is feeling as this may provide some useful information about their current symptoms.


Make sure the patient's notes, observation chart and prescription chart are easily accessible.

Ask for another clinical member of staff to assist you if possible.

If the patient is unconscious or unresponsive, start the basic life support (BLS) algorithm as per resuscitation guidelines.


Clinical assessment

Can the patient talk?

Yes: if the patient can talk, their airway is patent and you can move on to the assessment of breathing.

Identifying and Intervening in Airway Compromise

When airway compromise is suspected, it is important to look for signs such as cyanosis, see-saw breathing, use of accessory muscles, diminished breath sounds and added sounds. Additionally, open and inspect the mouth for anything that may be obstructing the airway, such as secretions or a foreign object.


Regardless of the underlying cause of airway obstruction, get immediate medical help from an anaesthetist and emergency medical team. In the meantime, basic airway manoeuvres can be done to help keep the airway open.

Head-tilt Chin-Lift Manoeuvre

To open the patient's airway using a head-tilt chin-lift manoeuvre:

  • Place one hand on the patient's forehead and the other under the chin.
  • Tilt the forehead back while lifting the chin forwards to extend the neck.
  • Inspect the airway for visible obstruction. If obstruction is present, use a finger sweep or suction to remove it.

Jaw Thrust

If the patient is suspected to have a spinal injury, perform a jaw-thrust instead of the head-tilt chin-lift manoeuvre:

  • Identify the angle of the mandible.
  • Use index and other fingers behind the angle of the mandible and apply steady, upwards and forward pressure to lift the mandible.
  • Slightly open the mouth by exerting downward pressure with thumbs.

Oropharyngeal Airway (Guedel)

Airway adjuncts can often be helpful, and sometimes necessary, to maintain the patient's airway. They should be used along with the manoeuvres previously mentioned to ensure that the head and neck are properly aligned. An oropharyngeal airway is a curved plastic tube with a flange on one end, that sits between the tongue and the hard palate. It should only be inserted in unconscious patients, as it can be poorly tolerated and induce gagging and aspiration.

To insert an oropharyngeal airway:

  • Open the patient's mouth and ensure there is no foreign material to be pushed into the larynx. Use suction if needed.
  • Insert the oropharyngeal airway upside-down until the junction of the soft and hard palate is reached, then rotate it 180°.
  • Advance the airway until it is within the pharynx.
  • Maintain the head-tilt chin-lift or jaw thrust and assess the patency of the airway by looking, listening and feeling for signs of breathing.

Nasopharyngeal Airway (NPA)

The nasopharyngeal airway is a soft plastic tube with a bevel at one end and a flange at the other, and is typically better tolerated in partly or fully conscious patients. It should not be used in patients with potential skull base fractures due to the risk of entering the cranial vault with the NPA.

To insert a nasopharyngeal airway:

  • Check the patency of the patient's right nostril and, if needed based on the model, pass a safety pin through the flange of the NPA.
  • Lubricate the NPA.
  • Insert the bevel-end first, vertically along the floor of the nose with a slight twisting action.
  • If obstruction is encountered, remove the tube and try the left nostril.

Other Interventions

If the patient has signs of anaphylaxis, such as stridor, bronchospasm, wheezing or a hoarse voice, administer adrenaline and consider intubation if symptoms do not improve.


Clinical Assessment


Review the patient's respiratory rate:

  • A normal respiratory rate is between 12-20 breaths per minute.
  • Tachypnoea in the context of AF may indicate pulmonary oedema secondary to heart failure or primary pulmonary pathology which is driving AF with RVR (e.g. pulmonary embolism, pneumonia).

Review the patient's oxygen saturation (SpO2):

  • A normal SpO2 range is 94-98% in healthy individuals and 88-92% in patients with COPD who are at high-risk of CO2 retention.
  • Hypoxaemia may be present in the context of heart failure secondary to AF with RVR.


Observe the patient for evidence of pain, distress or anxiety.


Auscultate the lungs:

  • Bibasal coarse crackles may suggest pulmonary oedema secondary to heart failure.
  • A focal region of coarse crackles may indicate an underlying infection which may be the trigger for AF with RVR.

Investigations and Procedures

Arterial blood gas

Take an ABG if indicated (e.g. low SpO2) to quantify the degree of hypoxia and assess for metabolic abnormalities.

Chest X-ray

A chest X-ray may be indicated if abnormalities are noted on auscultation (e.g. reduced air entry, coarse crackles) to screen for evidence of AF triggers (e.g. pneumonia, pulmonary oedema). A chest X-ray should not delay the emergency management of atrial fibrillation.

Sputum Culture

Ask the nursing staff to obtain a sputum sample to be sent to the microbiology lab for culture and sensitivity if the patient has a productive cough.

This information can be useful later to understand the causative organism and its antibiotic sensitivities.



Administer oxygen to all critically unwell patients during your initial assessment if oxygen saturations are below the normal range (<94%). This typically involves the use of a non-rebreathe mask with an oxygen flow rate of 15L. If the patient has COPD and a history of CO2 retention you should switch to a venturi mask as soon as possible and titrate oxygen appropriately.

If the patient is conscious, sit them upright as this can also help with oxygenation.


If the patient loses consciousness and there are no signs of life on assessment, put out a crash call and commence CPR.


Make sure to re-assess the patient after any intervention.


Clinical Assessment


Assess the patient's pulse rate: Patients with AF with RVR will be tachycardic.

Blood Pressure

Assess the patient's blood pressure. Most patients with AF will be haemodynamically stable, however, a minority may become haemodynamically unstable. Haemodynamic instability is typically associated with prolonged periods of tachycardia (e.g. >150 bpm). If a patient develops haemodynamic instability in the context of AF, urgent senior input should be sought as DC cardioversion may be required to prevent cardiac arrest.

Capillary Refill Time

Capillary refill time may be prolonged in atrial fibrillation with associated haemodynamic instability.

Fluid Status Assessment

Assess the patient's fluid status to determine if they are hypervolaemic, euvolaemic or hypovolaemic. Fluid status assessment involves:

  • Inspecting the oral mucosa for hydration
  • Capillary refill time assessment as above
  • Assessment of jugular venous pressure (JVP)
  • Review of the patient's fluid input and output

Hypovolaemia is a known trigger for AF and should be treated appropriately.

Apex Beat

Locate and palpate the apex beat. The apex beat is typically located in the 5th intercostal space in the midclavicular line. A displaced apex beat may indicate underlying ventricular hypertrophy.

Investigations and Procedures

Intravenous Cannulation

Insert at least one wide-bore intravenous cannula (14G or 16G) and take blood tests as discussed below.

Blood Tests

Collect blood tests after cannulating the patient including:

  • FBC: to rule out anaemia and to look for a raised white cell count which may suggest underlying infection.
  • U&Es: to assess renal function and rule out electrolyte disturbances.
  • CRP: to screen for evidence of inflammation (e.g. pneumonia).
  • Troponin: if considering acute myocardial infarction or rate-related ischaemia.
  • Coagulation studies: to assess for coagulopathy or assess the patient's current level of anticoagulation (e.g. INR).
  • Thyroid function tests: to rule out hyperthyroidism which is a known trigger for AF.


An ECG should be performed to confirm the diagnosis of AF and to screen for evidence of ischaemic (e.g. ST elevation). Typical ECG findings in the context of AF include: Irregularly irregular rhythm, absence of P waves.



Emergency electrical cardioversion is required in people with life-threatening haemodynamic instability caused by new-onset atrial fibrillation. Consider either pharmacological (e.g. flecainide, amiodarone) or electrical cardioversion depending on clinical circumstances and resources in people with new‑onset atrial fibrillation who will be treated with a rhythm control strategy. In people with atrial fibrillation in whom the duration of the arrhythmia is greater than 48 hours or uncertain and considered for long‑term rhythm control, delay cardioversion until they have been maintained on therapeutic anticoagulation for a minimum of 3 weeks. During this period offer rate control as appropriate.

Treating Precipitating Factors

AF is commonly triggered by other factors and definitive management of AF requires the underlying triggers to be addressed (e.g. fluid resuscitation for hypovolaemia, antibiotics for an infection).

Rate Control

If someone is presenting acutely with atrial fibrillation and is not haemodynamically unstable, offer either rate control or rhythm control if the onset of the arrhythmia was less than 48 hours, and start rate control if it has been more than 48 hours or is uncertain.

Rate control is often needed to manage AF with rapid ventricular response. In an acute situation, beta-blockers like metoprolol and diltiazem/verapamil are preferred over digoxin as they act quickly. Which drug and target heart rate is chosen will depend on patient-specific characteristics (heart conditions, ejection fraction). Generally, cardiac output is kept at an optimal level by sustaining a heart rate less than 110 bpm at rest, which may require the use of multiple drugs. If heart rate can't be regulated within 110 bpm, the patient may need to be admitted for additional rate-controlling therapies.

Rhythm Control

Rhythm control therapy may be considered for patients who are still symptomatically affected despite adequate rate control therapy, but it has not been shown to influence long-term outcomes. Rhythm control may be offered to those with AF who are not haemodynamically unstable.


For those with AF, there is an increased chance of stroke from emboli, which can be reduced significantly with long-term oral anticoagulation using a suitable agent such as a direct-acting oral anticoagulant or warfarin. The CHA2DS2-VASc and ORBIT scoring tools can calculate the risk of stroke and risk of bleeding, respectively. In the acute setting, anticoagulation can be initially established with heparin.

Fluid Resuscitation

Hypovolaemic patients require fluid resuscitation:

  • Administer a 500ml bolus of Hartmann's solution or 0.9% sodium chloride (warmed if available) within 15 minutes.
  • Administer 250ml boluses in those at a greater risk of fluid overload (e.g. heart failure).

Assess for symptoms of fluid overload (e.g. auscultation of the lungs, assessment of JVP) after each bolus. Repeat up to four times (two times for those at risk of fluid overload), assessing the patient each time. Seek advice from a senior if the patient's condition worsens (e.g. increased chest crackles) or is not responding to multiple boluses (e.g. persistent hypotension).


Intravenous furosemide may be given to treat pulmonary oedema:

  • Furosemide increases urine output and helps expel fluid from the lungs.
  • If the patient is hypotensive, diuretics can cause shock, in which case input from critical care is needed to determine the best management strategy.


If the patient loses consciousness and has no signs of life, call for help and begin CPR.


After any intervention, make sure to re-assess the patient.

Assess the Patient's Level of Consciousness

When assessing a patient, use the AVPU scale to evaluate their level of consciousness:

  • Alert: The patient is aware, though they may not be oriented.
  • Verbal: The patient responds when spoken to with words or a grunt.
  • Pain: The patient responds to a painful stimulus such as supraorbital pressure.
  • Unresponsive: The patient does not show any responses of eye, voice or motor.

If a more accurate evaluation is needed, use the Glasgow Coma Scale (GCS).


Assess the patient's pupils:

  • Inspect the size and symmetry of the patient's pupils.
  • Examine direct and consensual pupillary responses.

Drug Chart Review

Evaluate the patient's drug chart to determine if any medications are causing a reduced level of consciousness, such as opioids, sedatives, anxiolytics, insulin, or oral hypoglycaemic medications.

Investigations and Procedures

Blood Glucose and Ketones

Measure the patient's capillary blood glucose level to screen for causes of a reduced level of consciousness, such as hypoglycaemia or hyperglycaemia. If an earlier investigation has already obtained the patient's glucose level, use that. The normal reference range for fasting plasma glucose is 4.0 – 5.8 mmol/l. Hypoglycaemia is defined as a plasma glucose of less than 3.0 mmol/l. If a hospitalised patient's glucose is ≤4.0 mmol/L and they are symptomatic, they should be treated.


Request a CT head scan if intracranial pathology is suspected after consulting with a senior.


Maintain the Airway

If the patient's GCS is 8 or below, seek urgent help from an anaesthetist. In the meantime, re-assess and preserve the patient's airway. Refer to the airway section of this guide for more information.


If the patient loses consciousness and there are no signs of life, call a crash team and begin CPR.


Be sure to re-assess the patient after each intervention.


If necessary, expose the patient during your assessment. Prioritise patient dignity and body heat conservation.

Clinical Assessment


Check for signs of peripheral oedema (e.g. heart failure) or swollen painful calves (e.g. deep vein thrombosis).


Measure the patient's temperature. If they have a fever, consider if an infection is present.



If an infection is suspected (e.g. consolidation on chest X-ray and fever), administer antibiotics as directed by local guidelines.


If the patient loses consciousness and there are no signs of life on assessment, call a crash team and initiate CPR.


It is important to re-assess the patient after any intervention.

Reassess ABCDE

Use the ABCDE approach to re-assess the patient and detect any changes in their condition, as well as to measure the effectiveness of the previously administered interventions.

If the patient shows signs of deterioration, act immediately and consider getting help from a senior member of the clinical team.


Another clinical team member, such as a nurse, should aid in the ABCDE assessment. This person should be able to perform observations, take samples to the lab, and catheterise if necessary.

Do not hesitate to seek assistance from a senior staff member if you have any doubts or concerns.

Next Steps

Now that the patient is stable and feeling much better, there are a few more steps to take.

Take a history

Re-examine the relevant medical history and, if the patient is confused, consider obtaining a collateral history from the staff or family members.


Review the patient's notes, charts, and recent investigation results. Examine the current medications and ensure that all regular medications are appropriately prescribed.


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