Delirium and withdrawal

Surgical approach (context)

Not an operation; delirium/withdrawal are perioperative syndromes that complicate surgical/ICU care.
- Surgeons typically: treat underlying surgical pathology (source control for sepsis, manage bleeding), rationalise lines/catheters, optimise mobilisation and nutrition, and coordinate MDT discharge planning.
- If delirium is severe: may request urgent imaging (CT head if focal neurology/trauma/anticoagulation), infection screen, and review analgesic/sedative plans with anaesthesia/ICU.

Anaesthetic management (perioperative approach)

Type of anaesthesia
- Prefer techniques that minimise deliriogenic drugs and physiological insult: regional/neuraxial where suitable; GA often required depending on surgery.
- Avoid/limit benzodiazepines (especially elderly/high risk) unless treating withdrawal or specific indications (e.g., status epilepticus).
Airway
- SGA acceptable for short, low aspiration-risk cases; ETT if aspiration risk, long surgery, laparoscopic, need controlled ventilation, or severe agitation/withdrawal requiring ICU-level sedation.
Duration
- Variable; risk rises with longer/complex surgery, ICU admission, and major inflammation (e.g., hip fracture, vascular, cardiac).
Painfulness
- Poorly controlled pain is a major delirium trigger; use multimodal analgesia and regional blocks where possible.
- Avoid excessive opioids; consider opioid-sparing strategies (paracetamol, NSAID if appropriate, ketamine low-dose in selected, lidocaine infusion in selected, neuraxial/PNB).
Intraoperative priorities to reduce delirium risk
- Maintain physiology: avoid hypotension, hypoxia, hypercarbia, hypoglycaemia, significant anaemia; treat sepsis; maintain normothermia.
- Depth of anaesthesia: avoid overly deep anaesthesia; consider processed EEG guidance in high-risk patients.
- Medication choices: minimise anticholinergics; avoid meperidine/pethidine; cautious with gabapentinoids in elderly/frail; consider dexmedetomidine where appropriate (ICU/postop sedation).

Definitions and classification

Delirium: acute, fluctuating disturbance of attention/awareness with additional cognitive disturbance, due to a medical condition/substance/withdrawal; develops over hours–days.
Phenotypes
- Hyperactive: agitation, hallucinations, combativeness.
- Hypoactive: withdrawn, drowsy, reduced motor activity (common; often missed; worse prognosis).
- Mixed: fluctuates between hyper/hypoactive.
Postoperative delirium (POD): delirium occurring after surgery (often within 24–72 h).
ICU delirium: delirium in critically ill; associated with longer ventilation/LOS and mortality.
Withdrawal syndromes: physiological and neuropsychiatric symptoms after reduction/cessation of a substance in a dependent patient.

Why it matters (outcomes)

Delirium is associated with increased mortality, longer hospital stay, institutionalisation, falls, complications, and long-term cognitive decline.
Withdrawal (especially alcohol/benzodiazepine) can cause seizures, autonomic instability, arrhythmias, aspiration, rhabdomyolysis, and death if untreated.

Risk factors (perioperative/ICU)

Patient factors
- Age, frailty, dementia/cognitive impairment, previous delirium, sensory impairment, Parkinson’s disease, depression.
- Alcohol use disorder, benzodiazepine dependence, polypharmacy, chronic pain/opioid use.
- Comorbidity: infection/sepsis, renal/hepatic failure, hypoxia/respiratory disease, heart failure, stroke.
Perioperative factors
- Emergency surgery, major surgery (hip fracture, vascular, cardiac), blood loss/anaemia, hypotension, hypothermia, pain, sleep disruption.
- Deliriogenic drugs: benzodiazepines, anticholinergics, high-dose opioids, some antihistamines, dopamine agonists; withdrawal from alcohol/benzos/opioids.
- ICU factors: mechanical ventilation, deep sedation, restraints, immobility, lack of day-night cues.

Recognition and diagnosis

Core features: acute onset + fluctuating course, inattention, altered level of consciousness, disorganised thinking/perceptual disturbance.
Screening tools
- 4AT (ward/PACU): Alertness, AMT4, Attention (months backwards), Acute change/fluctuation. Score ≥4 suggests delirium.
- CAM / CAM-ICU (ICU): acute change/fluctuation + inattention + (disorganised thinking or altered consciousness).
- RASS for arousal/sedation; delirium assessment requires patient arousable enough (e.g., RASS -3 to +4 for CAM-ICU use).
Differentiate from
- Dementia (chronic, non-fluctuating), depression, psychosis, pain/anxiety, hypoxia/hypercapnia, stroke, non-convulsive status epilepticus.

Immediate approach to the delirious patient (A–E + cause)

Safety first: protect patient/staff; 1:1 nursing if needed; de-escalation; avoid physical restraint if possible (can worsen agitation/injury).
A–E assessment and treat reversible physiology
- Airway/ventilation: check hypoxia, hypercapnia, aspiration; consider ABG/VBG.
- Circulation: hypotension, arrhythmia, shock, bleeding; check Hb, ECG, lactate.
- Disability: glucose, temperature, pain score, pupils, focal neurology; consider seizures/withdrawal.
- Exposure: infection sources, urinary retention/constipation, drug chart review, lines/catheters.
Targeted investigations (guided by context)
- FBC, U&E, LFT, CRP, glucose, Mg/PO4, TFT if indicated; ABG; urinalysis/culture; blood cultures if febrile; CXR; ECG.
- CT head if: new focal deficit, head trauma/fall, anticoagulated, persistent reduced consciousness, suspected intracranial pathology.

Non-pharmacological management (first-line for most)

Reorientation and environment: clocks/calendars, glasses/hearing aids, familiar objects, consistent staff, reduce noise, day-night cues, avoid unnecessary alarms.
Sleep promotion: minimise overnight disturbances, avoid deliriogenic sedatives; consider earplugs/eye masks; address pain and dyspnoea.
Early mobilisation and physiotherapy; avoid bed rest where possible.
Hydration/nutrition: treat dehydration; correct electrolytes; consider thiamine in at-risk alcohol users.
Remove/avoid triggers: urinary catheter if not needed, treat constipation/urinary retention, review drugs (stop anticholinergics/benzos where possible).
Family involvement and reassurance; consider delirium-friendly communication strategies.

Pharmacological management of delirium (when needed)

Principle: treat underlying cause; drugs are for severe distress, risk to self/others, or to enable essential care (e.g., imaging, ventilation).
Antipsychotics (use cautiously)
- Haloperidol: small doses, titrate; avoid in Parkinson’s/Lewy body dementia; monitor QTc and extrapyramidal effects.
- Atypicals (e.g., olanzapine/quetiapine) sometimes used; consider sedation, hypotension, QTc; local policy varies.
Dexmedetomidine (ICU setting): may reduce delirium duration and facilitate extubation in agitated ventilated patients; watch bradycardia/hypotension.
Benzodiazepines: generally avoid for non-withdrawal delirium; indicated for alcohol/benzodiazepine withdrawal and seizures.
Analgesia optimisation: treat pain; consider regional techniques; avoid opioid over-sedation; consider opioid rotation if neurotoxicity suspected (e.g., renal failure).

Alcohol withdrawal (including delirium tremens)

Timeline (typical): tremor/anxiety 6–12 h; seizures 12–48 h; hallucinosis 12–48 h; delirium tremens (DT) 48–96 h (can be later).
Clinical features: tremor, agitation, sweating, tachycardia, hypertension, fever, hallucinations, confusion; severe: seizures, arrhythmias, hyperthermia, dehydration.
Assessment: history of dependence/previous DT/seizures; quantify use; consider CIWA-Ar on wards (not validated in intubated ICU patients).
Treatment
- Benzodiazepines are first-line: symptom-triggered or fixed-dose regimen (e.g., diazepam/chlordiazepoxide; lorazepam if liver disease).
- Severe/ICU: IV benzodiazepine titration; consider adjuncts (dexmedetomidine or clonidine for autonomic symptoms; phenobarbital in refractory cases per local protocol).
- Thiamine before glucose in at-risk patients to reduce risk of Wernicke’s encephalopathy; replace magnesium and phosphate.
- Fluids, temperature control, treat infection/other triggers; consider ICU if DT, recurrent seizures, severe autonomic instability, or need for airway protection.
Wernicke’s encephalopathy: confusion, ophthalmoplegia/nystagmus, ataxia (triad often incomplete). Treat urgently with parenteral thiamine.

Benzodiazepine withdrawal

Features: anxiety, insomnia, tremor, perceptual disturbance, agitation, seizures, delirium; higher risk with short-acting agents and abrupt cessation.
Management: reinstate and taper benzodiazepine (often diazepam equivalent) gradually; treat seizures with benzodiazepines; consider ICU if severe agitation/seizures.

Opioid withdrawal (including iatrogenic ICU withdrawal)

Features: mydriasis, yawning, lacrimation/rhinorrhoea, piloerection, abdominal cramps/diarrhoea, tachycardia, anxiety, insomnia; not usually life-threatening but can cause severe distress and sympathetic surge.
Management: continue baseline opioid (or equivalent) perioperatively; use opioid substitution (e.g., methadone/buprenorphine plans with specialist input); clonidine/lofexidine for autonomic symptoms; antiemetics/antidiarrhoeals; multimodal analgesia.
Patients on buprenorphine: anticipate higher opioid requirements; plan with pain/addiction team (options include continuing buprenorphine with additional opioids, or temporary modification depending on surgery and local policy).

Nicotine withdrawal

Features: irritability, anxiety, restlessness, poor concentration, insomnia; may contribute to agitation/delirium in ICU.
Management: nicotine replacement therapy (patch + short-acting form) unless contraindicated; address sleep and anxiety non-pharmacologically first.

Other important causes to consider (mimics/precipitants)

Sepsis, hypoxia/hypercapnia, metabolic derangements (Na/Ca/glucose), renal/hepatic failure, drug toxicity (opioids, anticholinergics), serotonin syndrome, neuroleptic malignant syndrome, thyroid storm.
Urinary retention and constipation are common, reversible precipitants postoperatively.

Prevention (perioperative and ICU bundles)

Risk identification: screen high-risk patients (frailty/cognitive impairment/alcohol dependence) preop; plan postoperative location and support.
Optimise analgesia: regional techniques; regular paracetamol; NSAID if appropriate; avoid excessive opioids and sedatives.
Avoid benzodiazepine premedication in elderly/high-risk unless specific indication.
Maintain physiology intraop: avoid hypotension/hypoxia/hypoglycaemia; maintain normothermia; treat anaemia appropriately.
ICU: use light sedation strategies, daily sedation holds when appropriate, early mobilisation, sleep hygiene, reorientation; consider ABCDEF bundle principles.
Alcohol dependence: prophylaxis plan (thiamine, electrolyte replacement, early benzodiazepine regimen if high risk) and early involvement of specialist teams.

You are called to PACU: an 82-year-old post-hip fracture repair is agitated and pulling at lines. How do you assess and manage?

Structure: immediate safety + A–E + identify/treat causes + non-pharm first + targeted drugs if needed.

Immediate safety: call for help, calm approach, ensure staff safety, consider 1:1 observation; check if pain, urinary retention, hypoxia.
A–E: SpO2/ETCO2 if available, RR, ABG/VBG if concern; BP/ECG; temperature; glucose; neuro exam for focal deficit; review fluid balance and Hb.
Review drugs: opioids, anticholinergics, benzodiazepines; consider opioid toxicity vs pain; check renal function for opioid metabolite accumulation.
Non-pharmacological: reorientate, ensure glasses/hearing aids, quiet environment, family presence if possible, treat constipation/retention, optimise sleep plan.
Analgesia: assess pain; consider fascia iliaca catheter/top-up; regular paracetamol; cautious opioid titration.
If severe agitation risking harm or preventing essential care: small-dose haloperidol with ECG/QTc check; avoid if Parkinson’s/Lewy body; consider ICU/dexmedetomidine if ongoing.
Search for precipitants: infection, hypoxia, anaemia, electrolyte disturbance, stroke; arrange labs and imaging if indicated.

Define delirium and distinguish it from dementia. What bedside tool would you use on the ward and in ICU?

Examiners want: definition, time course, fluctuation, attention; and named tools.

Delirium: acute (hours–days), fluctuating disturbance of attention/awareness with cognitive change, due to a medical condition/substance/withdrawal.
Dementia: chronic, progressive cognitive decline; attention often preserved early; not typically fluctuating hour-to-hour.
Ward/PACU tool: 4AT (rapid screen). ICU tool: CAM-ICU (with RASS to ensure assessable arousal).

List perioperative risk factors for delirium and give a prevention strategy for each.

Aim: show you can link risk to modifiable prevention.

Older age/frailty/cognitive impairment → preop identification, involve family, delirium-friendly environment, avoid benzodiazepine premed.
Pain and high opioid exposure → regional analgesia, multimodal regimen, regular pain assessment, avoid pethidine.
Hypotension/hypoxia/hypercapnia → vigilant monitoring, treat promptly, consider depth monitoring to avoid overly deep anaesthesia.
Sleep disruption/ICU factors → light sedation, day-night cues, minimise overnight interventions, early mobilisation (bundle approach).
Alcohol dependence → thiamine, Mg/PO4 replacement, early withdrawal plan (benzodiazepine regimen), early specialist input.

An intubated ICU patient becomes tachycardic, hypertensive, sweaty and agitated on weaning sedation. How do you differentiate delirium from withdrawal and manage?

Key is structured assessment, drug history, and targeted therapy while maintaining safety and ventilation goals.

Check timeline and exposure: recent reduction in opioids/benzodiazepines/alcohol history; review infusion history and weaning rate.
Assess for pain, hypoxia/hypercapnia, sepsis, urinary retention, hypoglycaemia; check ABG, lactate, temperature, cultures if indicated.
Use RASS + CAM-ICU when arousable; delirium often fluctuates with inattention; withdrawal has prominent autonomic features and improves with replacement therapy.
Management: treat causes; if opioid withdrawal suspected → reinstate/convert to longer-acting opioid and taper; consider clonidine/dexmedetomidine for sympathetic symptoms.
If benzodiazepine withdrawal suspected → benzodiazepine replacement and gradual taper; seizures treated with benzodiazepines.
Avoid deep, prolonged sedation; aim for light sedation targets and daily review; involve ICU pharmacist/pain team.

Describe alcohol withdrawal and delirium tremens: timeline, features, and treatment in the perioperative patient.

Examiners want: time course + autonomic features + benzo-first-line + thiamine/electrolytes + ICU triggers.

Timeline: symptoms 6–12 h; seizures 12–48 h; hallucinosis 12–48 h; DT typically 48–96 h after cessation (may be later).
Features: tremor, agitation, confusion, hallucinations, fever, tachycardia, hypertension, sweating; severe: seizures, arrhythmias, dehydration, hyperthermia.
Treatment: benzodiazepines first-line (symptom-triggered or fixed-dose); lorazepam if significant liver disease; supportive care and monitoring.
Give thiamine (parenteral if high risk) and replace Mg/PO4; treat concurrent sepsis/bleeding; consider ICU for DT, seizures, severe autonomic instability, or airway risk.

What are the indications and contraindications for haloperidol in delirium? What monitoring is required?

Focus on when to use, when not to, and key adverse effects.

Indications: severe agitation/distress, risk of harm, or to facilitate essential investigations/treatment after non-pharmacological measures and cause-treatment.
Contraindications/cautions: Parkinson’s disease/Lewy body dementia, prolonged QTc/known ventricular arrhythmia risk, significant electrolyte abnormalities (low K/Mg), severe CNS depression.
Monitoring: ECG for QTc, electrolytes (K/Mg), observe for extrapyramidal side effects, sedation, hypotension; use lowest effective dose and review regularly.

A postoperative patient is confused and drowsy. Give a differential diagnosis and an investigation plan.

Aim: broad but structured; include common reversible causes and dangerous diagnoses.

Differential: residual anaesthetic/sedative effects, opioid excess, hypoxia/hypercapnia, hypotension/shock, sepsis, hypoglycaemia, electrolyte disturbance (Na/Ca), stroke/ICH, alcohol/benzo withdrawal, urinary retention, pain.
Investigations: obs + ECG; capillary glucose; ABG; FBC/U&E/LFT/CRP; Mg/PO4; cultures if febrile; CXR; bladder scan; consider CT head if focal neurology/trauma/anticoagulated/persistent low GCS.

How does pain management influence delirium risk, and what analgesic plan would you propose for a high-risk elderly patient?

Show balance: untreated pain vs opioid over-sedation; propose opioid-sparing multimodal plan.

Uncontrolled pain increases stress response and delirium risk; excessive opioids increase sedation, CO2 retention, and delirium risk.
Plan: regional analgesia where possible (e.g., fascia iliaca for hip fracture), regular paracetamol, NSAID if appropriate, cautious opioid titration with monitoring, avoid pethidine; consider low-dose ketamine only in selected patients and with monitoring.
Review renal/hepatic function and adjust drug choice; frequent reassessment and early mobilisation.

What is Wernicke’s encephalopathy and how does it relate to perioperative delirium? What is your immediate management?

Key: recognise and treat early; thiamine before glucose.

Wernicke’s encephalopathy due to thiamine deficiency (often alcohol misuse/malnutrition); features: confusion, ophthalmoplegia/nystagmus, ataxia (often incomplete).
It can present as delirium; untreated can progress to Korsakoff syndrome.
Immediate management: give parenteral thiamine urgently (per local protocol) and correct electrolytes; give thiamine before glucose-containing fluids in at-risk patients.

Outline a perioperative plan for a patient at high risk of alcohol withdrawal undergoing emergency laparotomy.

Examiners want: anticipate withdrawal, resuscitate, thiamine/electrolytes, benzodiazepine strategy, ICU planning.

Preop: assess dependence and previous DT/seizures; baseline obs, ECG, labs (including Mg/PO4); give thiamine; correct electrolytes and dehydration; treat sepsis/bleeding.
Intraop: avoid hypotension/hypoxia; multimodal analgesia with regional where feasible; minimise benzodiazepines unless needed for withdrawal; temperature and glucose control.
Postop: high-dependency/ICU consideration; early benzodiazepine regimen (symptom-triggered or fixed-dose) with monitoring; consider dexmedetomidine/clonidine adjunct if severe autonomic symptoms; continue thiamine and electrolyte replacement.
Delirium prevention bundle: reorientation, sleep hygiene, early mobilisation, avoid deliriogenic drugs, treat pain and retention/constipation.