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Anaesthesia in the older patient
In old age the reserve of every system shrinks — the heart is stiff and depends on volume and rhythm, the kidney clears slowly, and the brain is sensitive — so doses are reduced, falls in blood pressure are avoided, and frailty and cognition are assessed before surgery.
Why it matters in the exam
The exam asks about the physiological changes of old age and what they mean for anaesthesia: a lower MAC, high sensitivity to propofol, benzodiazepines and opioids, a "normal" creatinine that hides a fall in glomerular filtration, airway closure during normal breathing, and weak laryngeal reflexes. It also asks about the timing of hip fracture surgery, nerve blocks for hip fracture and drugs best avoided (the Beers criteria).
An older patient's left ventricle is stiffer, and filling depends on atrial contraction — atrial fibrillation or hypovolaemia reduces output. The response to sympathetic stimulation and to beta-blockers is weaker, so hypotension at induction is deeper. MAC falls by about 6% per decade after age 40. Muscle mass is smaller, so a normal creatinine can hide a significant fall in kidney function. Closing capacity exceeds the FRC, so saturation is lower even in health.
Before surgery frailty is assessed (for example with the Clinical Frailty Scale), together with cognition, daily function, nutrition and the drug list, and goals of care and advance directives are discussed. In hip fracture surgery is done early — on the day of admission or the day after — and an early nerve block is given to reduce opioids. After surgery the focus is on early mobilisation, good analgesia, delirium prevention and a quick return to eating.
Key points
- A stiff heart dependent on volume and rhythm; sharp hypotension at induction.
- MAC falls about 6% per decade; small doses.
- A normal creatinine misleads — calculate clearance.
- Frailty and cognition predict risk more than age.
- Hip fracture: early surgery and a nerve block.
Summary table
| System | Change with age | Meaning for anaesthesia |
|---|---|---|
| Heart and vessels | Stiff ventricle, dependence on atrial contraction, weak sympathetic response | Sharp hypotension at induction; keep sinus rhythm and volume |
| Breathing | Closing capacity above FRC, weak laryngeal reflexes | Hypoxaemia and aspiration |
| Kidney | Lower filtration; a "normal" creatinine misleads | Adjust doses by calculated clearance |
| Brain and drugs | MAC falls about 6% per decade; sensitivity to benzodiazepines and opioids | Small doses; avoid benzodiazepines (Beers) |
| Temperature and body | Weak thermoregulation; less muscle, more fat | Hypothermia; larger volume of distribution for lipid-soluble drugs |
A free exam question
?כיצד ניתן להוריד את התחלואה והתמותה לאחר שבר צוואר ירך בקשיש (the question as examined, in Hebrew)
- א. לאשפז למספר ימים כדי לאפשר הערכה והכנה לפני הניתוח
- ב. לנתח מוקדם ככל הניתן
- ג. להרדים תחת ניטור על ידי TEE
- ד. להתחיל טיפול מונע לתסחיפים
In the full version for subscribers
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Sources
- Miller's Anesthesia, 9th edition (2020) — Geriatric Anesthesia
- American Geriatrics Society Beers Criteria for Potentially Inappropriate Medication Use in Older Adults, 2023 — Drugs to avoid
- NICE guideline CG124: Hip fracture — management, 2011, updated 2023 — Timing of surgery and analgesia
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.