8.1 Medical Emergencies & Resuscitation
Key Takeaways
- The Resuscitation Council UK (RCUK) 2021 adult BLS algorithm uses a 30:2 compression-to-ventilation ratio, 5-6 cm compression depth, 100-120 compressions/min, with full chest recoil and minimal interruptions
- ABCDE (Airway, Breathing, Circulation, Disability, Exposure) is the structured initial assessment for every dental medical emergency before a working diagnosis is made
- Vasovagal syncope is the commonest dental emergency: lay the patient flat, raise the legs, loosen tight clothing, give fresh air, and reassure — recovery is usually within minutes
- Hypoglycaemia in a conscious patient is managed with 15-20 g of fast-acting oral carbohydrate; an unconscious or uncooperative patient receives glucagon 1 mg IM and 999 is called if recovery is delayed
- In suspected acute coronary syndrome (MI), give aspirin 300 mg chewed, oxygen only if hypoxic (SpO2 < 94%), and call 999 immediately; GTN sublingual (0.3-0.6 mg or one spray) relieves angina
The ABCDE Approach
Every medical emergency in the dental surgery begins with a structured ABCDE assessment (Resuscitation Council UK). This is the single most testable framework in MFDS Part 1 because it is emergency-agnostic — you apply it before forming a working diagnosis.
| Step | Assess | Act |
|---|---|---|
| Airway | Patency, obstruction, noises | Head tilt / chin lift, suction, airway adjuncts |
| Breathing | Rate, depth, effort, SpO2, cyanosis | Oxygen 15 L/min via non-rebreather mask if unwell |
| Circulation | Pulse rate/rhythm, capillary refill, BP, colour | Lay flat + raise legs if shock; CPR if no pulse |
| Disability | AVPU, pupils, glucose, seizures | Check blood glucose; recovery position if unconscious |
| Exposure | Temperature, rash, bleeding | Keep warm; expose only as needed |
Always check a blood glucose level in any patient with reduced consciousness or seizures — hypoglycaemia is a reversible mimic of many emergencies.
Adult Basic Life Support (RCUK 2021)
When a patient is unresponsive and not breathing normally, start CPR immediately and send for the automated external defibrillator (AED) and an ambulance (999).
Key BLS Parameters
| Parameter | RCUK 2021 Standard |
|---|---|
| Compression : ventilation ratio | 30 : 2 |
| Compression depth | 5-6 cm on the lower half of the sternum |
| Compression rate | 100-120 per minute |
| Recoil | Allow full chest recoil; avoid leaning |
| Interruptions | Minimise — hands on chest as much as possible |
| Rescue breaths | Each breath ~1 second, visible chest rise |
- If you are alone and unwilling or unable to give rescue breaths, perform continuous chest compressions.
- Attach the AED as soon as it arrives and follow its voice prompts — defibrillation is the only definitive treatment for ventricular fibrillation.
- Continue CPR until: the patient shows signs of life, qualified help takes over, the AED prompts analysis, or you are exhausted.
Recovery Position
Place an unconscious patient who is breathing normally in the lateral recovery position to protect the airway. In dentistry this is the default position for the post-ictal patient and the recovering vasovagal patient once consciousness returns.
Choking
| Severity | Signs | Action |
|---|---|---|
| Mild | Cough, able to speak | Encourage cough; do not interfere |
| Severe | Unable to speak, silent, cyanosis | 5 back blows, 5 abdominal thrusts (Heimlich), alternate |
If the patient becomes unconscious, start CPR and call 999 — chest compressions may dislodge the obstruction. Never perform a blind finger sweep in the mouth.
Common Dental Chair Emergencies
Syncope (Vasovagal)
The commonest dental emergency, triggered by pain, anxiety, or the sight of blood/instruments. Prodrome: pallor, sweating, nausea, tunnel vision.
Management:
- Stop treatment; lay the patient flat (supine).
- Raise the legs to improve venous return.
- Loosen tight clothing; ensure fresh air / give oxygen if available.
- Reassure; recovery usually within a few minutes.
- Differentiate from other causes (cardiac, hypoglycaemia, anaphylaxis) — persistent loss of consciousness demands a wider differential and 999.
Hypoglycaemia
- Conscious/cooperative: give 15-20 g fast-acting carbohydrate (e.g. glucose tablets, GlucoGel, non-diet fizzy drink); repeat after 15 min if needed.
- Unconscious/uncooperative: give glucagon 1 mg IM; once conscious, give oral glucose.
- Call 999 if recovery is delayed or glucagon is unavailable. Always check blood glucose early.
Seizures (Epileptic)
- During the seizure: protect from injury (do not restrain), secure the airway, give oxygen 15 L/min, time the seizure.
- Post-ictal: place in the recovery position once convulsions stop; reassess.
- Status epilepticus (seizure >=5 minutes or repeated without recovery): give buccal midazolam 10 mg (adult, 2 mL of 5 mg/mL oromucosal solution) and call 999. Rectal diazepam 10-20 mg is an alternative where buccal midazolam is unavailable.
Asthma Attack
- Give the patient's own salbutamol inhaler (2-4 puffs via a spacer); reassure and allow a seated posture.
- Severe (inability to complete sentences, RR > 25, SpO2 < 92%): give oxygen and nebulised salbutamol 5 mg, and call 999.
Angina and Acute Coronary Syndrome (MI)
| Condition | Recognition | Immediate Management |
|---|---|---|
| Angina | Central crushing chest pain, may radiate to jaw/arm, on exertion/anxiety | GTN sublingual 0.3-0.6 mg (or one spray, 400 mcg); sit patient up; repeat once after 5 min if no relief. If pain persists > 15 min, treat as MI. |
| Myocardial infarction (MI) | Persistent chest pain, sweating, nausea, dyspnoea | Give aspirin 300 mg chewed; oxygen only if hypoxic (SpO2 < 94%); sit patient up; call 999 immediately; consider GTN if not contraindicated. |
Cardiac Arrest
The patient is unresponsive and not breathing normally. Start CPR (30:2), call 999, send for the AED, and follow the AED prompts. Early defibrillation is the single most important determinant of survival.
A 45-year-old patient in the dental chair suddenly becomes pale, sweaty, and loses consciousness. The pulse is faint but present, and breathing is normal. What is the most appropriate immediate management?
According to the Resuscitation Council UK 2021 adult basic life support algorithm, what is the correct compression-to-ventilation ratio and compression depth for an adult in cardiac arrest?
A patient with known type 1 diabetes becomes confused and tremulous during a long restorative appointment. Blood glucose is 3.1 mmol/L. The patient is still conscious and cooperative. What is the most appropriate immediate treatment?
An epileptic patient begins a generalised tonic-clonic seizure in the dental chair. It has lasted five minutes and shows no sign of stopping. What is the most appropriate next step?