The elderly patient and postoperative delirium

Why examiners ask this

The 84-year-old with a hip fracture is the archetypal post-op stem. The examiner wants to see that you screen for frailty and cognitive impairment, prevent delirium with a multicomponent plan, and treat an agitated patient by finding the cause instead of reaching for a sedative. It tests judgment and adaptability, and often adds a capacity or consent question.

The 60-second answer

Decision points and the "why"

• Preoperative screening — the ASA Perioperative Brain Health Initiative recommends a baseline cognitive screen such as the Mini-Cog for every older surgical patient, and delirium screening before PACU discharge and twice daily afterward;² with a frailty assessment it sets expectations and identifies who needs the full prevention bundle.
• Regional versus general — the evidence, including the REGAIN trial in 1,600 hip-fracture patients (delirium 20.5% spinal vs 19.7% general), shows no difference;³ the 2024 ASA advisory likewise finds neither technique superior.⁴ I choose based on the patient and surgery and focus on what does reduce delirium: avoiding deep sedation, controlling pain and avoiding harmful drugs.
• Depth of anesthesia — processed EEG reduces anesthetic exposure. Trials of EEG guidance, including ENGAGES, have not reduced delirium,⁵ but burst suppression marks an overdose for the aging brain, so I use it in every elderly patient and avoid suppression.
• Drug choices — no benzodiazepine premedication; avoid anticholinergics; use glycopyrrolate rather than atropine because it does not cross the blood-brain barrier; reduce doses for age-related changes in pharmacokinetics.
• Analgesia — a fascia iliaca or femoral block for hip fracture reduces pain on movement and acute confusional state (high-certainty evidence);⁶ acetaminophen scheduled; low-dose opioids for breakthrough.
• Dexmedetomidine — the 2024 ASA advisory considers it reasonable to lower delirium risk in patients 65 and older, weighed against bradycardia and hypotension;⁴ I use it as a sedative and analgesic adjunct in higher-risk patients.
• Antipsychotics — not a first response; the Beers Criteria reserve them for when nonpharmacologic measures fail and the patient threatens substantial harm.¹ Haloperidol 0.25–0.5 mg then; they do not shorten delirium, and they prolong QT.

The complication they will inject

On the first postoperative night after a hip hemiarthroplasty, the 84-year-old pulls out her IV and is shouting; the nurse requests lorazepam. I decline, because benzodiazepines worsen delirium and are not a first-line response.² I go to the bedside and evaluate: SpO2, glucose, temperature, blood pressure, pain score, bladder scan, and a blood gas and electrolytes. I look for new focal neurologic signs that point to a stroke and fat embolism symptoms after the joint procedure. I treat what I find, ask the family to sit with her, reorient her and remove tethers such as the catheter when safe. If she remains dangerously agitated, I give haloperidol 0.5 mg after checking the QT. I explain to the family that delirium is common, usually resolves, but is associated with longer stay and later cognitive decline.

Pitfalls that cost points

• Treating agitation with a sedative before finding the cause.
• Missing hypoactive delirium, the most common form, which looks like a quiet, sleepy patient.
• Claiming regional anesthesia prevents delirium.
• Giving diphenhydramine for sleep or itching.
• Forgetting to involve the family and to discuss goals of care.

Rapid-why

Q: Why are the elderly more sensitive to anesthetics? A: Reduced neuronal reserve, lower MAC, smaller volume of distribution and slower clearance.

Q: Why does pain cause delirium? A: It disrupts sleep, raises stress hormones and drives opioid use; both untreated pain and excessive opioids increase risk.

Q: How is delirium different from postoperative cognitive dysfunction? A: Delirium is acute, fluctuating inattention in the first days; POCD is a subtle decline in memory and executive function measured over weeks to months.

Q: Why does urinary retention cause agitation? A: A distended bladder is painful and stimulating; the elderly patient cannot localize or report it.

Numbers to know

Links

• Delayed emergence, Emergence delirium (coming), Opioids and postoperative respiratory depression, Femoral, adductor canal and popliteal blocks (coming), Ethical issues: DNR, capacity, surrogates, refusal
• ACS and AGS Optimal Perioperative Management of the Geriatric Patient best practices guideline
• American Geriatrics Society Beers Criteria (2023)