Collapse in the chair during an extraction in an insulin-treated patient
A 62-year-old man attends at 11:30 am for extraction of tooth 47. He has type 2 diabetes managed with insulin glargine at night and glimepiride in the morning. He says he ate breakfast at 7 am and took his usual medication, and that he has been too busy to eat since. Ten minutes into the appointment, immediately after the local anaesthetic, he becomes pale and sweaty, with a fine tremor in his hands, and complains of feeling 'odd' and hungry. He is drowsy but rousable and can swallow. His pulse is 112 beats per minute and regular, blood pressure 138/84, respiratory rate 20, and he is not complaining of chest pain. He is not in pain at the site and the extraction has not yet begun.
1. What is your working diagnosis, and how do you distinguish it from the alternatives?
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Working diagnosis: hypoglycaemia. The reasoning is pattern recognition, then exclusion.
Features supporting hypoglycaemia:
- Insulin and a sulfonylurea, a missed meal since 7 am, and an appointment near midday - the classic set-up. Sulfonylureas make hypoglycaemia more likely and more prolonged.
- Autonomic warning signs: pallor, sweating, tremor, tachycardia, hunger.
- Neuroglycopenic signs: drowsiness, feeling 'odd', reduced responsiveness.
Alternatives and why they fit less well:
- Vasovagal syncope: possible after an injection, but would typically give bradycardia and hypotension, and recovery is prompt on being laid flat. A pulse of 112 with a normal blood pressure argues against it.
- Acute coronary syndrome / angina: no chest pain, no radiation, no dyspnoea; his profile still means keeping it on the differential if he does not respond to treatment.
- Local anaesthetic toxicity: would follow a large intravascular dose and typically presents with perioral tingling, tinnitus, metallic taste, agitation or seizure, not hunger and tremor after a single cartridge.
- Hyperglycaemia: gradual onset, thirst, polyuria, drowsiness without adrenergic signs; not a 10-minute event.
A bedside glucometer reading, if immediately available, converts this from a clinical impression to a measurement - but treatment is not delayed to obtain it.
2. Set out your immediate management, including what you would and would not do.
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Immediate management
- Stop treatment. Recline the chair, remove instruments and any packing from the mouth; do not leave him alone. Summon a second staff member and note the time.
- He is conscious and able to swallow, so give 15-20 g of fast-acting oral carbohydrate: glucose gel, glucose tablets, or 150-200 mL of sugary drink. Do not use diet drinks - they contain no glucose.
- Recheck after 10-15 minutes. If still symptomatic or the reading remains low, repeat the dose. If he improves, follow with a longer-acting carbohydrate (biscuit, sandwich) to prevent recurrence, especially with a sulfonylurea on board.
- Call 000 if he deteriorates, cannot swallow, loses consciousness, or does not respond to two doses. Sulfonylurea-induced hypoglycaemia can be prolonged and recurrent, so a low threshold for transfer is correct even after apparent recovery.
What not to do
- Do not put anything in the mouth of an unconscious or unsafe-to-swallow patient - risk of aspiration.
- Do not give insulin or anything that lowers glucose.
- Do not simply sit him up and give him water, which is the common error when this is mistaken for fainting.
- Do not discharge him alone or allow him to drive.
If he becomes unconscious: recovery position, airway, breathing, circulation, call 000, and give IM glucagon 1 mg if available; IV dextrose is a paramedic/hospital measure. Record observations, timing, treatment and response contemporaneously.
3. Once he has recovered, how do you close the loop - both for today and for future appointments?
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For today
- Do not resume the extraction. Explain why: hypoglycaemia impairs judgement and coordination, and the stress of the procedure risks a second episode.
- Confirm he is symptom-free, has eaten, and has a responsible adult to escort him; advise no driving.
- Recommend he contact his GP, because a sulfonylurea plus insulin with a missed meal is a regimen question, not just a one-off event. Write to the GP describing the episode and the measured glucose.
- Record everything contemporaneously, including that he was advised not to drive.
For future appointments
- Morning appointments shortly after a meal and usual medication, not a fasting or midday slot.
- Ask at the appointment: 'What and when did you last eat? Did you take your diabetes medication?' If he has not eaten, reschedule or have him eat first - this is a decision, not a formality.
- Keep a glucose source and a glucometer in the surgery, check expiry dates, and ensure at least one staff member is trained in its use and in Basic Life Support; glucagon if the practice stocks it.
- Have a written medical emergency protocol and rehearse it; assign roles.
- Consider shorter, well-planned appointments and effective local anaesthesia to minimise stress, since pain and anxiety amplify the adrenergic picture and confuse the diagnosis.