The ABCDE approach can be used to perform a systematic assessment of a critically unwell patient. It involves working through the following steps:
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.
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.
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).
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:
Typical symptoms of new-onset AF include:
Atrial fibrillation (AF) is a common arrhythmia, with typical symptoms including:
Typical clinical signs of AF include:
General tips for applying an ABCDE approach in an emergency setting include:
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.
Yes: if the patient can talk, their airway is patent and you can move on to the assessment of breathing.
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.
To open the patient's airway using a head-tilt chin-lift manoeuvre:
If the patient is suspected to have a spinal injury, perform a jaw-thrust instead of the head-tilt chin-lift manoeuvre:
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:
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:
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.
Review the patient's respiratory rate:
Review the patient's oxygen saturation (SpO2):
Observe the patient for evidence of pain, distress or anxiety.
Auscultate the lungs:
Take an ABG if indicated (e.g. low SpO2) to quantify the degree of hypoxia and assess for metabolic abnormalities.
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.
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.
Assess the patient's pulse rate: Patients with AF with RVR will be tachycardic.
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 may be prolonged in atrial fibrillation with associated haemodynamic instability.
Assess the patient's fluid status to determine if they are hypervolaemic, euvolaemic or hypovolaemic. Fluid status assessment involves:
Hypovolaemia is a known trigger for AF and should be treated appropriately.
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.
Insert at least one wide-bore intravenous cannula (14G or 16G) and take blood tests as discussed below.
Collect blood tests after cannulating the patient including:
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.
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).
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 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.
Hypovolaemic patients require fluid resuscitation:
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:
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.
When assessing a patient, use the AVPU scale to evaluate their level of consciousness:
If a more accurate evaluation is needed, use the Glasgow Coma Scale (GCS).
Assess the patient's pupils:
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.
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.
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.
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.
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.
Now that the patient is stable and feeling much better, there are a few more steps to take.
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.
