Anesthesiology APPLIED Exam › Ambulatory, non-OR and special populations

The elderly patient and postoperative delirium

Ambulatory, non-OR and special populations·~5 min read· Physician-reviewed✓ Sourced · 6

Stem

An 84-year-old woman, 52 kg, is scheduled for hemiarthroplasty after a fall with a displaced femoral neck fracture. She lives with her daughter, uses a walker, wears hearing aids, and has mild forgetfulness. Her medications include amlodipine, oxybutynin and diphenhydramine at night for sleep. She is in pain, and her vital signs are normal.

Question

She is at high risk for postoperative delirium. How will you reduce that risk from now through her recovery?

Ideal answer

HeadlineShe is at high risk of postoperative delirium, so prevention starts now: screen her cognition, stop her anticholinergics and block the hip pain.

Mini-Cog, frailty, function, sensory deficits, medications, because pre-existing cognitive impairment is the strongest predictor of postoperative delirium.¹
Stop oxybutynin and diphenhydramine, both anticholinergic, and avoid other deliriogenic drugs: benzodiazepines, scopolamine and meperidine.²
Fascia iliaca block now, acetaminophen scheduled, because pain itself causes delirium and the block reduces both pain and acute confusion.³
Spinal or general on her merits, not for delirium, because neither is superior;⁴ blood pressure near baseline, processed EEG against excessive depth and burst suppression, normothermia.
Afterward, glasses, hearing aids, orientation, sleep, mobility, family,¹ with delirium screening before PACU discharge and twice daily.

Watch for: delirium; if it develops, I look for the cause before reaching for a sedative.

Breaking down the answer

Who gets screened — the ASA Perioperative Brain Health Initiative recommends a baseline cognitive screen for every older surgical patient;¹ with a frailty assessment it sets expectations and picks out who needs the full prevention bundle.
Regional versus general — REGAIN, 1,600 hip-fracture patients: delirium 20.5% spinal vs 19.7% general;⁵ the 2024 ASA advisory likewise finds neither superior.⁴ What does reduce delirium: avoiding deep sedation, controlling pain, avoiding harmful drugs.
Depth of anesthesia — processed EEG reduces anesthetic exposure. Trials of EEG guidance, including ENGAGES, have not reduced delirium,⁶ but burst suppression marks an overdose for the aging brain, so I use it in every elderly patient.
Drug choices — no benzodiazepine premedication; glycopyrrolate rather than atropine because it does not cross the blood-brain barrier; doses reduced for age-related changes in pharmacokinetics.
The evidence for the block — a fascia iliaca or femoral block for hip fracture reduces pain on movement and acute confusional state (high-certainty evidence);³ low-dose opioids only 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.² Haloperidol 0.25–0.5 mg then; they do not shorten delirium, and they prolong QT.

Follow-up question

On the first postoperative night she pulls out her IV and is shouting, and the nurse asks for lorazepam. What do you do?

Follow-up answer

HeadlineThis is delirium. I decline the lorazepam, because benzodiazepines worsen delirium,¹ and go to the bedside to find the cause.

SpO2, glucose, temperature, blood pressure, pain score, bladder scan, a blood gas and electrolytes: hypoxemia, hypercarbia, sepsis, retention, drug effects. New focal neurologic signs point to a stroke; I consider fat embolism 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, haloperidol 0.5 mg after checking the QT. I explain that delirium is common and usually resolves but is associated with longer stay and later cognitive decline, and I reassess her with CAM.

Pitfalls that cost points

Missing hypoactive delirium, the most common form, which looks like a quiet, sleepy patient.
Giving diphenhydramine for sleep or itching.
Forgetting to involve the family and to discuss goals of care, including capacity and consent.

Rapid-fire

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

Item	Value
Delirium incidence after hip fracture	~20% in REGAIN; higher in many series⁵
MAC reduction per decade over 40	~6%
Haloperidol for agitation	0.25–0.5 mg IV/PO
CAM features	Acute onset, inattention, plus disorganized thinking or altered consciousness
Mini-Cog	3-word recall plus clock draw

Sources

1.6 simple steps physician anesthesiologists can lead to reduce delirium (Perioperative Brain Health Initiative) · ASA, 2021 · asahq.org
2.2023 AGS Beers Criteria pocket card · American Geriatrics Society (via USC GWEP), 2023 · gwep.usc.edu
3.Peripheral nerve blocks for hip fractures in adults (plain language summary) · Cochrane, 2020 · cochrane.org
4.Recommendations may help reduce delirium in older patients having surgery (practice advisory) · ASA, 2024 · asahq.org
5.Spinal Anesthesia or General Anesthesia for Hip Surgery in Older Adults (REGAIN journal scan) · American College of Cardiology, 2021 · acc.orgNeuman et al., NEJM 2021; n=1600.
6.The ENGAGES Pragmatic Trial and the Power of Negative Thinking · NIH Pragmatic Trials Collaboratory, 2019 · rethinkingclinicaltrials.org

Facts on this page were checked against these sources on Oct 14, 2026. Guidelines change; confirm doses against current institutional protocols.