Medical and endocrine disease18 / 30
Motor neurone disease: sedation for PEG in endoscopy58-year-old man, 72 kg, booked for percutaneous endoscopic gastrostomy in the endoscopy suite
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Know this first
- Vital capacity under 50% predicted predicts ventilatory failure after anaesthesia.
- Sedatives and opioids hit him hard; aspiration and airway obstruction are likely.
- Suxamethonium is contraindicated: life-threatening hyperkalaemia.
- Remote sites need theatre-standard oxygen, suction, monitoring, staff and resuscitation kit.
The patient
58-year-old man, 72 kg, booked for percutaneous endoscopic gastrostomy in the endoscopy suite.
Motor neurone disease with bulbar weakness: slurred speech, choking on fluids, weak cough; vital capacity 45% predicted.
NIV overnight at home. Drugs: riluzole.
Vitals: BP 128/76, HR 96, SpO2 94% on air, RR 22.
The examiner asks
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Consider
What are the issues?
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- A 58-year-old with motor neurone disease, bulbar weakness and a vital capacity of 45%, for PEG in endoscopy. Patient
- Choking and a weak cough mean he probably aspirates already; I look for chest infection. Disease
- His vital capacity under 50% predicts ventilatory failure after sedation or anaesthesia.
- Sedatives and opioids affect him strongly, and his airway obstructs easily.
- His resting rate of 96 may be autonomic involvement; postural drops are common too.
- Endoscopy is a remote site, far from theatre help. Surgery
Prepare
How do you prepare for this?
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- Any chest infection treated first, with a low threshold for a chest X-ray. Disease
- Before sedation, I discuss his goals of care, intubation and resuscitation, and record his ceiling. After surgery
- Room check: piped oxygen and backup cylinder, reliable suction, airway kit, defibrillator and drugs. Surgery
- A trained assistant beside me and a reliable way to call for help.
- His own NIV machine comes with him for use during and after the procedure. Disease
Plan
What is your sedation plan?
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- Capnography from start to finish, as for any deeply sedated patient. Disease
- Minimal sedation in small titrated steps; midazolam no more than 1–2 mg, opioids avoided.
- Low-dose ketamine is an option that spares his breathing.
- Throat spray blunts his gag and raises aspiration risk, so I use it sparingly. Airway
- Head up, suction in my hand, with his NIV on if his breathing weakens.
- No suxamethonium; if paralysis is needed, a reduced non-depolarising dose with proven full reversal. Disease
- Afterwards, NIV and close watch for drowsiness and rising CO2. After surgery
Crisis
Mid-procedure he gurgles and coughs; SpO2 falls to 82%, RR 30, HR 118. What do you do?
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- Aspiration of pooled secretions in a weak, sedated man; the scope comes out and sedation stops. Crisis
- Head down and suction his mouth and pharynx, then 100% oxygen.
- Jaw support and bag-mask breaths if his own effort fails.
- Naloxone 40 mcg every 2 minutes, or flumazenil 0.1–0.2 mg, if drugs are depressing him.
- If he can't be supported, I follow his agreed plan: intubate only within his stated wishes.
- Then a chest X-ray and HDU watch for pneumonitis, on his NIV. After surgery
Fatal mistakes
- Suxamethonium in his denervated muscle.
- Deep sedation with no capnography.
- Intubating him against the ceiling of care he agreed.
Checked against: Miller 10e · Barash 9e · Recommendations for standards of monitoring during anaesthesia and recovery 2015: Association of Anaesthetists of Great Britain and Ireland · Faust
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