Rheumatoid arthritis for shoulder replacement in the beach chair70-year-old woman, 60 kg, for elective total shoulder replacement in the beach-chair position

The patient

The examiner asks

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1. Consider

   What are your concerns?

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   • A 70-year-old with long-standing rheumatoid arthritis and lung changes, for elective shoulder replacement sitting up. Patient
   • At 70, frailty, cognition and reserve matter; her RA also carries cardiac risk like type 2 diabetes.
   • Pain into the occiput may be atlantoaxial subluxation; flexion can push the odontoid into her cord. Airway
   • Hoarseness or stridor would suggest cricoarytenoid arthritis; I also check her jaw opening.
   • Her lung fibrosis leaves little reserve for an interscalene block's phrenic paralysis. Disease
   • Methotrexate, adalimumab and prednisolone bring infection risk and adrenal suppression.

2. Prepare

   How will you assess her?

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   • Flexion-extension neck films with odontoid views; a gap over 3 mm means real subluxation risk. Airway
   • ECG, because rheumatoid infiltration can cause conduction block. Disease
   • Lung function and her baseline saturation of 94%, to judge if she can lose a hemidiaphragm.
   • Full blood count: her Hb is 10.8, and methotrexate can suppress the marrow.
   • Prednisolone above 5 mg: on surgery day she gets hydrocortisone 50–75 mg IV, tapering over 1–2 days.
   • Adalimumab and methotrexate timing agreed with her rheumatologist, given her infection risk.

3. Plan

   What is your anaesthetic plan?

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   • Neck neutral: video laryngoscopy with in-line stabilisation, or awake fibreoptic if her neck is unstable. Airway
   • A smaller tube, or a supraglottic airway, if her cricoarytenoids are involved.
   • Her lungs may not tolerate a phrenic block, and severe neck disease favours general without a block. Disease
   • Arterial line zeroed at her ear, so I read the pressure her brain gets. Surgery
   • Each centimetre above the heart costs 0.75 mmHg; 20 cm costs her brain 15 mmHg.
   • Ephedrine, atropine and glycopyrrolate drawn up before she is sat up. Crisis
   • Her deformed joints and pressure areas padded and positioned gently. Surgery

4. Crisis

   Ten minutes after she is sat up, HR falls from 72 to 38 and the arterial line, zeroed at her ear, reads 58/28. What do you do?

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   • Bradycardia algorithm: HR 38 with hypotension is unstable, likely a beach-chair hypotensive bradycardic event. Crisis
   • Zeroed at her ear, that is her brain's pressure: a MAP near 38, critically low.
   • Bring her flat with legs raised to refill her underfilled ventricle; surgeon told.
   • Atropine 1 mg IV now; repeat each 3–5 minutes to a 3 mg ceiling.
   • No response: adrenaline infusion 2–10 mcg/min, or transcutaneous pacing.
   • Her reversible causes: venous pooling, and adrenal suppression if her hypotension persists.
   • Once stable, she is filled before being sat up again, slowly. After surgery