34.4 Syncope, Adrenal Crisis, Choking and Resuscitation

Detailed Emergency Protocols

6. Vasovagal Syncope (Simple Faint)

• Pathophysiology: The most common medical event in dental practice. Emotional stress, pain, or phobia triggers an inappropriate autonomic reflex: excessive parasympathetic vagal discharge induces cardioinhibition (bradycardia), while sympathetic withdrawal causes peripheral vasodilation and venous pooling (hypotension). The resulting drop in cerebral perfusion triggers transient loss of consciousness.
• Management:
  1. Immediate Positioning: Recline the dental chair completely flat (horizontal) and elevate the patient's legs. This promotes venous return to the right atrium and rapidly restores cerebral blood flow.
  2. Loosen restrictive clothing around the neck; ensure cool ambient airflow.
  3. Maintain airway patency; administer oxygen if recovery is delayed.
  4. Consciousness typically returns within 30–60 seconds. If recovery is prolonged, re-evaluate ABCDE and check capillary blood glucose.

7. Adrenal Crisis

• Pathophysiology: Patients with Addison's disease or secondary adrenal suppression due to long-term systemic corticosteroid therapy ($\ge 5\text{ mg}$ prednisolone daily for $>3$ weeks within the preceding year) cannot produce endogenous cortisol in response to the physiological stress of dental surgery, leading to acute vascular collapse.
• Clinical Presentation: Profound, refractory hypotension, tachycardia, dizziness, nausea, vomiting, abdominal pain, hypovolaemic shock, and loss of consciousness.
• Management:
  1. Call 999 immediately.
  2. Lay the patient flat with legs elevated.
  3. Administer Hydrocortisone 100 mg IM or IV.
  4. Administer high-flow oxygen (15 L/min) and maintain warmth while awaiting paramedic transfer for intravenous fluid resuscitation.

8. Choking & Foreign Body Airway Obstruction (FBAO)

                     Suspected Foreign Body Aspiration / Ingestion
                                          │
             ┌────────────────────────────┴────────────────────────────┐
             ▼                                                         ▼
      Mild Obstruction                                          Severe Obstruction
  - Patient CAN speak, cough, breathe                        - Ineffective cough, CANNOT speak
  - Audible wheeze                                           - Severe stridor / silent chest
  - Action: ENCOURAGE COUGHING                               - Clutching neck ("Universal Choking Sign")
  - DO NOT INTERVENE WITH BLOWS                              - Rapid cyanosis
                                                                       │
                 ┌─────────────────────────────────────────────────────┴──────────────────┐
                 ▼                                                                        ▼
       Conscious Adult Patient                                                  Unconscious Patient
  - Deliver 5 SHARP BACK BLOWS                                           - Support safely to the floor
    (between scapulae with heel of hand)                                 - Call 999 immediately
  - If unsuccessful:                                                     - Commence CPR (30:2)
    Deliver 5 ABDOMINAL THRUSTS (Heimlich)                               - Inspect oral cavity each time
  - Alternate 5 back blows / 5 abdominal thrusts                           airway is opened (no blind sweeps)

• Mandatory Dental Protocol for Lost Objects: If a small dental object (bur, implant screwdriver, tooth fragment, crown) is lost into the oropharynx and not recovered:
  • Assess airway and breathing immediately.
  • If the patient is asymptomatic, never discharge them without mandatory imaging.
  • Arrange immediate hospital referral for an urgent Chest X-Ray (CXR) and Abdominal X-Ray (AXR). A foreign body aspirated into the tracheobronchial tree (most commonly the wider, more vertical right main bronchus) can cause pulmonary atelectasis, lung abscess, or fatal late airway obstruction if missed.

9. Cardiopulmonary Resuscitation (CPR) & Automated External Defibrillation (AED)

In the event of unresponsiveness and absent or abnormal breathing (agonal gasps), the dental team must immediately initiate basic life support:

1. Call for Help: Instruct a designated team member to dial 999 and retrieve the Automated External Defibrillator (AED) and emergency oxygen cylinder.
2. High-Quality Chest Compressions:
   • Position the patient supine on a firm, flat surface (floor or flattened dental chair base).
   • Place hands on the centre of the chest (lower half of sternum).
   • Compress at a rate of 100 to 120 compressions per minute.
   • Compress to a depth of 5 to 6 cm in adults.
   • Allow complete chest recoil after each compression; avoid leaning on the chest.
   • Minimize interruptions to chest compressions ($<10\text{ seconds}$). Switch compressors every 2 minutes to avoid fatigue.
3. Compression-to-Ventilation Ratio:
   • Perform 30 chest compressions followed by 2 rescue breaths (30:2 ratio) using a pocket mask or bag-valve-mask connected to high-flow oxygen (15 L/min).
4. Defibrillation Protocol:
   • Turn on the AED and attach pads immediately (right pad below right clavicle; left pad in mid-axillary line below left axilla).
   • If a shockable rhythm (Ventricular Fibrillation / Pulseless Ventricular Tachycardia) is identified, ensure everyone is clear and deliver 1 shock. Immediately resume CPR (30:2) for 2 minutes before the next rhythm check.
   • If a non-shockable rhythm (Asystole / Pulseless Electrical Activity) is identified, resume CPR immediately.

Aspiration, Inhalation and the Role of Rubber Dam

A specifically dental variant of airway obstruction is the inhaled or swallowed foreign body — a restoration, an endodontic file, a bur, a crown or an extracted tooth. The immediate response is to stop, keep the patient still, and, if possible, retrieve the object with suction or forceps. If the object cannot be found, the patient must be referred for chest and abdominal radiography, because an inhaled object requires bronchoscopic removal, while a swallowed object is usually managed conservatively unless it is sharp. The incident is recorded, the patient told what has happened, the duty of candour applied and a significant event analysis undertaken. The examinable preventive measures are rubber dam for endodontics and restorative work, floss ligatures on small instruments and crowns, a gauze throat pack where dam is impossible, high-volume aspiration, and careful patient positioning.

Candidates should also be able to state the adult basic life support sequence in the order the Resuscitation Council UK publishes it: check for danger, check responsiveness, open the airway and check breathing for no more than ten seconds, call 999 and send for the automated external defibrillator, and begin chest compressions at a depth of five to six centimetres and a rate of 100 to 120 per minute with a compression to ventilation ratio of 30 to 2, minimising interruptions. The defibrillator is attached as soon as it arrives and its prompts are followed. Agonal gasping is not normal breathing and must not delay compressions.