What is it?

Acute confusional state


Can't focus

  • Altered cognition
  • Rapid onset medical illness
  • Psychomotor activity
    • Hyperactive
    • Hypoactive
    • Fidgeting

Primary causes of confusion

Infection 40%

  • Urinary Tract Sepsis,
    LRTI, Skin, Biliary Sepsis

Drugs 20%

Neurological 10%

Dehydration 5%

Fever - Sepsis - WCC - Elderly NOT Typical


  • Fever is mediated by IL-1, TNF-alpha
  • These “pyrogens” stimulate hypothalamus
  • Increases the temperature set point
  • The body then meets that new set point

This may not happen in older people


Leukocytosis you need:

  • A reactive, well working bone marrow
  • Quick acting inflam. mediators
  • A reserve of precursor cells for release from marrow

This may not happen in older people


4AT - Assessment test for delirium and cognitive impairment.
[1] Alertness
This includes patients who may be drowsy or agitated/hyperactive. Observe the patient. If asleep, attempt to wake with speech or gentle touch on shoulder. Ask the patient to state their name and address to assist rating.
  Normal (fully alert, not agitated, throughout assessment) 0
  Mild sleepiness for <10 seconds after waking, then normal 0
  Clearly abnormal 4
[2] AMT4
Age, DoB, place (name of the hospital), current year.
  No mistakes 0
  1 mistake 1
  ≥2 mistakes / untestable 2
[3] Attention
MOTYB. Ask the patient: “Please tell me the months of the year in backwards order, starting at December.”
  Achieves ≥7 months correctly 0
  Starts but scores <7 months / refuses to start 1
  Untestable (cannot start / drowsy/ inattentive) 2
[4] Acute Δ or fluctuating course
Evidence of significant change or fluctuation in: alertness, cognition, other mental function (eg. paranoia, hallucinations) arising over the last 2 weeks and still evident in last 24hrs
  No 0
  Yes 4

≥4: possible delirium ± cognitive impairment.
1-3: possible cognitive impairment
0: delirium / cognitive impairmemt unlikley but delirium still possible if [4] incomplete.

Clinical approach

  • ABCs (↓O2, spesis, ↓Glu)
  • Remember the principal causes above
    • If in doubt treat for sepsis
  • Note Motor Activity
    • Restless
    • Drowsy
    • Figetting
  • Attention span?
  • Perceptual disturbances
  • Phone the relative


  • Appearance
  • Behaviour
  • Speech and attitude
  • Disorders of thought
  • Disorders of perception
  • Mood and affect
  • Insight and judgement
  • Sensorium and intelligence

Management tips

  • ABC (particularly hypoxia)
  • DEFG (e.g. hyperglycaemia, DKA or hypoglycaemia)
  • Pain, constipation, urinary retention, / Na+, ↑Ca++ easily missed
  • If in doubt: cultures and treat for sepsis (resp., UTI, biliary, skin)
  • Actively seek/treat dehydration
  • Think toxicology (particularly alcohol/withdrawal)
  • Pabrinex ([i+ii]x2 (total 4 vials), tds)in all (e.g. ↓Na+, ↑Ca++)
  • Consider CT brain after admission to hospital
  • Firm calm communication, constant reorientation, have a relative present
  • If sedation required and safe, use Benzos ± Haloperidol in preference to Respiridone, Olanzapine or Quetiapine

Delirium sedation

Never use physical restraint.

Sedation drugs after all above considered.

Drug/Route StartDose Sedation EPS
Respiridone, PO / IM 0.25-0.5 mg + +++
Olanzapine, PO / SL / IM 2.5-5 mg ++ ++
Quetiapine, PO 12.5-25 m ++++ +
Second line agents
Haloperidol, PO / IM/IV (ICU) 0.25-0.5 mg + ++++
Lorazepam PO/IM/IV
BDZ for ETOH or
sedative withdrawal
0.25-0.5 mg +++ 0

Content by Dr Dan Ryan 16/02/2010. Review and PINCHME added by Dr Andrew Patton 19/12/2020. Last review Dr ÍOS 24/11/21 .