Medical Emergencies: Recognition and Drugs

Medical Emergencies in Dental Practice

Medical emergencies can and do occur at any time within a dental practice setting. The dental team treats a wide demographic of patients, many of whom present with complex, underlying systemic medical conditions. Furthermore, the inherent anxiety associated with dental treatment, the administration of local anaesthetics, and the use of various dental materials can act as potent triggers for acute physiological crises. Dental nurses play a critical, frontline role in the recognition of these medical emergencies, the prompt assistance of the operating dentist, and the ongoing maintenance of all emergency equipment to ensure it is immediately ready and fully functional. The General Dental Council (GDC) strictly requires all registered dental professionals to be robustly trained and competent in dealing with medical emergencies, which fundamentally includes annual updates in cardiopulmonary resuscitation (CPR) and basic life support (BLS) as per the Resuscitation Council UK guidelines.

Essential Emergency Drugs and Equipment

Under UK guidelines, every dental practice is legally obligated to maintain a standardized, fully stocked emergency drugs kit and an automated external defibrillator (AED). This equipment must be stored in a known, accessible central location, completely free from locks or physical barriers that could delay access during a crisis. The dental nurse is typically responsible for conducting and logging weekly checks to ensure no medications have expired and that the oxygen cylinder is sufficiently full. The core mandated drugs include:

• Adrenaline (Epinephrine) 1:1000 injection: This is the primary, life-saving treatment for anaphylaxis. It acts as a powerful vasoconstrictor and bronchodilator. The standard adult dose is 0.5ml (500 micrograms), administered directly intramuscularly (IM) into the anterolateral aspect of the thigh (the vastus lateralis muscle). Pre-loaded auto-injectors (e.g., EpiPen) are common, but ampoules and syringes must also be available.
• Aspirin dispersible (300mg): Used in cases of suspected myocardial infarction (heart attack). Aspirin has rapid antiplatelet properties, helping to prevent the further enlargement of a blood clot in the coronary arteries. The patient must consciously chew or dissolve the tablet in their mouth to ensure rapid mucosal absorption; swallowing it whole delays the clinical effect.
• Glucagon (1mg injection): This hormone is used for the management of severe hypoglycaemia in unconscious patients. It is administered via intramuscular injection. Glucagon works by stimulating the liver to rapidly convert stored glycogen into usable glucose in the bloodstream. It must be stored in a refrigerator but can be kept at room temperature for up to 18 months.
• Oral glucose gel / powder (e.g., Glucogel or Dextrogel): Used for hypoglycaemia when the patient is conscious and able to swallow safely. It provides a rapid spike in blood glucose levels.
• Glyceryl trinitrate (GTN) spray (400 micrograms/dose): This is a potent vasodilator used for the rapid relief of angina pectoris or to assist during a myocardial infarction. It is administered sublingually (under the tongue) where the dense capillary network allows for rapid systemic absorption.
• Midazolam (10mg/ml buccal liquid): Used strictly for the termination of prolonged, continuous seizures (status epilepticus). It is a sedative and muscle relaxant applied to the buccal mucosa (between the cheek and gum) where it is absorbed into the bloodstream. It must never be injected intravenously by a dental nurse.
• Salbutamol aerosol inhaler (100 micrograms/actuation): A short-acting bronchodilator used to reverse bronchospasm during asthma attacks. It should always be administered via a large-volume spacer device to maximize the delivery of the drug directly into the lungs.
• Oxygen: Medical oxygen is vital for most emergencies. It is delivered via a size D or CD cylinder equipped with a pressure reduction valve and flow meter, utilizing a non-rebreathe mask with a reservoir bag set to deliver a high flow of 15 litres per minute.

Comprehensive Management of Common Emergencies

1. Anaphylaxis

Anaphylaxis is a severe, systemic, and life-threatening Type 1 allergic hypersensitivity reaction. It is characterized by the massive, sudden release of histamine. Symptoms escalate rapidly and include dramatic facial and laryngeal swelling (angioedema), severe difficulty breathing due to bronchospasm, a widespread erythematous rash (urticaria), and a profound drop in blood pressure leading to anaphylactic shock. Management: Call the emergency services (999) immediately. Lay the patient flat to maintain cerebral perfusion, unless they are struggling to breathe, in which case a semi-recumbent position is preferred. Administer IM adrenaline (0.5mg for adults) immediately into the thigh. If there is no clinical improvement after 5 minutes, administer a second dose. Deliver high-flow oxygen at 15 L/min.

2. Asthma Attack

An acute exacerbation of asthma can be triggered by stress, dental aerosols, or allergens. The patient's airways constrict and secrete excess mucus. Presentation includes severe breathlessness, an audible expiratory wheeze, persistent coughing, distress, and tachycardia. Management: Sit the patient upright to maximize lung expansion. Administer the patient's own reliever inhaler if available; if not, immediately use the practice's emergency salbutamol inhaler attached to a spacer. Administer up to 10 puffs, pressing the canister once and allowing the patient to take 5 deep tidal breaths per puff. Provide oxygen. If the patient becomes exhausted, cyanotic, or if symptoms fail to improve within 5 minutes, dial 999 immediately.

3. Cardiac Arrest and Myocardial Infarction (MI)

Angina is a reversible restriction of blood flow to the heart, whereas a Myocardial Infarction (heart attack) involves the irreversible death of heart muscle due to complete coronary artery occlusion. Symptoms include severe, crushing, central chest pain that often radiates to the left arm, neck, or jaw. This is typically accompanied by severe breathlessness, profound pallor, nausea, and cold, clammy sweating. If the patient collapses, stops responding, and stops breathing normally, they have progressed into cardiac arrest. Management for MI: Stop treatment, call 999, and sit the patient in a comfortable 'W' position. Administer 2 puffs of sublingual GTN spray. Instruct the patient to chew a 300mg aspirin tablet. Administer high-flow oxygen and provide constant reassurance. Management for Cardiac Arrest: Follow the DRSABCD protocol (Danger, Response, Shout for help, Airway, Breathing, CPR, Defibrillation). Call 999 and explicitly state "cardiac arrest". Commence CPR immediately on a firm surface at a ratio of 30 chest compressions (at a depth of 5-6cm and a rate of 100-120 per minute) to 2 rescue breaths. Ensure the practice AED is retrieved immediately, switch it on, apply the pads to the patient's bare chest, and follow all voice prompts. Do not halt CPR unless the patient demonstrates clear signs of life, the AED specifically instructs you to pause for analysis, or paramedics physically take over.

4. Epilepsy and Seizures

Seizures are electrical disturbances in the brain, often triggered by anxiety, flashing lights, or missed anti-epileptic medication. The most severe presentation in the dental chair is a generalized tonic-clonic seizure, involving sudden loss of consciousness, total body rigidity (the tonic phase), followed by violent, rhythmic jerking movements (the clonic phase). The patient may become cyanotic or incontinent. Management: Your primary duty is to protect the patient from physical injury. Do not forcefully restrain the patient's limbs, and under no circumstances should you force a mouth prop or any object between their teeth. Clear away all bracket tables, instruments, and hazards. Accurately time the duration of the seizure. Once the active jerking stops, place the patient into the recovery position to maintain a clear airway during the post-ictal (recovery) phase. If the active seizure continues for longer than 5 minutes, it is classified as status epilepticus. Call 999 immediately and administer 10mg of buccal midazolam to the inside of the cheek.

5. Hypoglycaemia

Hypoglycaemia occurs when blood glucose drops below 4.0 mmol/L. It is most commonly seen in diabetic patients who have injected their normal insulin dose but failed to consume adequate carbohydrates before their appointment. Symptoms present in two stages: initially, adrenaline-mediated signs like sweating, severe trembling, and palpitations; followed by neuroglycopenic signs as the brain is starved of glucose, leading to confusion, slurred speech, irrational aggression, and eventual coma. Management (Conscious): Immediately provide a fast-acting, easily absorbable oral carbohydrate, such as Glucogel, a high-sugar drink, or glucose tablets. Once the patient stabilizes, follow this with a long-acting carbohydrate like a biscuit or sandwich to prevent a secondary crash. Management (Unconscious): Do not put any food or drink in an unconscious patient's mouth due to the high risk of fatal aspiration. Call 999. Place the patient in the recovery position and administer 1mg of IM glucagon.

6. Syncope (Vasovagal Fainting)

Syncope is the most common emergency in dentistry. It is a transient loss of consciousness caused by a sudden, severe drop in blood pressure and a temporary reduction in cerebral blood flow, typically triggered by intense anxiety, pain, or the sight of needles. Management: Immediately lay the patient completely flat and elevate their legs above the level of their heart to mechanically force venous blood back to the brain. Ensure the airway is open, loosen any tight clothing around the neck, and provide a cool, well-ventilated environment. Recovery should be rapid; if the patient does not regain full consciousness quickly, immediately suspect a more serious underlying cause.

7. Choking

The supine position in the dental chair puts patients at risk of inhaling small instruments, cotton rolls, or fractured teeth. Management: If the patient has a mild obstruction and is coughing forcefully, encourage them to continue coughing. If the obstruction is severe (the patient is completely silent, clutching their throat, and turning cyanotic), immediately perform up to 5 sharp back blows between the shoulder blades. If this fails, perform up to 5 abdominal thrusts (the Heimlich manoeuvre). Alternate these techniques until the object is dislodged. If the patient loses consciousness, begin CPR.