34.1 The ABCDE Approach and the Emergency Drug Kit

The Systematic ABCDE Approach

Whenever a patient deteriorates acutely in the dental chair, the clinical team must immediately institute the ABCDE systematic paradigm. This prioritizes life-threatening physiological derangements in order of lethality:

                                  The Systematic ABCDE Approach
                                                │
      ┌──────────────────┬──────────────────────┼──────────────────────┬──────────────────┐
      ▼                  ▼                      ▼                      ▼                  ▼
  A: Airway          B: Breathing           C: Circulation         D: Disability      E: Exposure
- Patency          - Respiratory rate     - Capillary refill     - AVPU score       - Cutaneous signs
- Stridor/snoring  - Rhythm, depth, work  - Pulse rate, rhythm   - Pupillary size   - Urticaria/rash
- Head-tilt chin-  - Chest symmetry       - Blood pressure       - Blood glucose    - Bleeding/trauma
  lift / suction   - SpO2 pulse oximetry  - Peripheral perfusion - Seizure activity - Core warmth

1. Airway (A): Assess patency. Look for chest movement, listen for airway noise (stridor implies upper airway oedema/obstruction; gurgling indicates fluid or blood; snoring indicates pharyngeal soft tissue collapse), and feel for air movement. Intervene with head-tilt chin-lift or jaw thrust; utilize high-volume suction to evacuate debris, blood, or impression materials.
2. Breathing (B): Assess respiratory rate (normal adult: 12–20 breaths/min; tachypnoea $>20$, critical $>25$; bradypnoea $<8$), respiratory effort, accessory muscle recruitment, and chest wall expansion. Auscultate or evaluate for wheeze. Measure peripheral arterial oxygen saturation ($SpO_2$) with pulse oximetry.
3. Circulation (C): Assess peripheral and central pulses (radial, carotid) for rate, rhythm, and volume. Measure capillary refill time (CRT) on the finger pulp (normal $\le 2\text{ seconds}$; prolonged indicates poor tissue perfusion). Record blood pressure. Observe skin pallor, cold clamminess, or peripheral cyanosis.
4. Disability (D): Evaluate level of consciousness using the rapid AVPU scale:
   • A: Alert
   • V: Responds to Voice
   • P: Responds to Pain
   • U: Unresponsive
   • Check pupillary symmetry and light reflexes. In all patients with altered sensorium, measure capillary blood glucose using a calibrated glucometer.
5. Exposure (E): Examine the body for diagnostic clues: urticarial wheals, angioedema, medical alert bracelets, transdermal drug patches, or surgical bleeding. Preserve patient dignity and prevent hypothermia.

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Mandatory Dental Emergency Drug Kit

Per the BNF Dental Practitioners' Formulary (DPF) and the Resuscitation Council UK, every primary care dental practice in the United Kingdom must hold an unexpired emergency drug armamentarium:

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Training, Equipment and Practice Preparedness

The regulator examines preparedness as well as knowledge. The GDC requires all members of the dental team to undertake medical emergencies and resuscitation training as part of their continuing professional development every year, and it is one of the recommended CPD topics. Practices are expected to hold and maintain the emergency drugs and equipment listed by the Resuscitation Council UK, to check them regularly against expiry dates, to record those checks, and to rehearse emergency scenarios as a team so that roles are known in advance.

The equipment list is examinable alongside the drugs: a portable oxygen cylinder with a pressure-reduction valve and flowmeter capable of delivering 15 litres per minute, oxygen masks with reservoir bags and tubing, basic airway adjuncts including oropharyngeal airways in a range of sizes, self-inflating bag-valve-mask devices with adult and child masks, portable suction with wide-bore aspiration tips, a pulse oximeter, a blood glucose meter, a blood pressure monitor, spacer devices for inhaled bronchodilators, and an automated external defibrillator. The AED is not optional in UK primary dental care, and knowing that is a common examination point.

Recognising Deterioration and Calling for Help

The purpose of the ABCDE sequence is to identify and treat the most immediately lethal problem before moving on, and to repeat the assessment after each intervention. Two habits distinguish safe practice. First, call for help early — 999 for an ambulance, and the whole practice team to the surgery — rather than waiting to reach a diagnosis; the systematic approach works precisely because it does not require a diagnosis to begin treatment. Second, record everything contemporaneously: the time of onset, observations, drugs given with dose, route and time, the response, and the time of the ambulance call and arrival. One team member should be tasked with timing and recording while another manages the patient.

Positioning: The Most Common Error

Position is the single intervention most often got wrong, and it differs by emergency. The faint and anaphylaxis are laid flat with the legs raised, because both are problems of reduced venous return; sitting an anaphylactic patient up can precipitate cardiac arrest. Acute coronary syndrome, acute asthma and acute left ventricular failure are sat upright, because their problem is respiratory work and pulmonary congestion. A pregnant patient beyond about 20 weeks who needs to lie flat is placed in a left lateral tilt to relieve aortocaval compression by the gravid uterus. An unconscious patient who is breathing normally with no suspicion of spinal injury is placed in the recovery position. Being able to state the position and the physiological reason for it is worth as much in the examination as naming the drug.