Anaesthesia in the Elderly

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Ageing physiology significantly impacts anaesthetic management due to reduced functional reserve in cardiovascular, respiratory, renal, hepatic, and neurological systems. Pharmacokinetic changes include reduced lean body mass (drug distribution altered), decreased plasma proteins (increased free drug fraction), reduced hepatic blood flow (delayed metabolism), and decreased GFR (prolonged drug excretion). Pharmacodynamic changes show increased sensitivity to anaesthetic agents (reduced MAC by 6-8% per decade after age 40, MAC at age 80 is ~0.6 MAC at age 40). Delirium occurs in 15-25% of elderly post-surgery, associated with increased mortality, prolonged hospitalization, and long-term cognitive decline; prevention includes regional anaesthesia where appropriate, multimodal analgesia (avoid meperidine, anticholinergics), early mobilization, and maintenance of sleep-wake cycles. Postoperative cognitive dysfunction (POCD) affects 10-15% of elderly at 3 months, risk factors include age >75, lower education, pre-existing cognitive impairment, prolonged anaesthesia, and respiratory complications. Drug dosing requires 20-30% dose reductions, titrating to effect with short-acting agents (propofol, remifentanil), avoiding long-acting benzodiazepines and anticholinergics. Indigenous elders face compounded risks from higher rates of comorbidities (diabetes, renal disease), reduced health literacy, and barriers to postoperative care, requiring culturally safe communication, family involvement in decision-making, and careful medication reconciliation. [1-10]