Durgical
EN
Open the app

ICU delirium: CAM-ICU and ICDSC screening, types, risk factors and prevention

  • Assessment

ICU delirium is a sudden, fluctuating confusion; nurses screen for it every shift with a validated tool, look for causes and prevent it.

Updated

What it is

Delirium is an acute disturbance of attention and awareness that comes on over hours to days and fluctuates. It is very common in ventilated patients and predicts longer ventilation and stay, long-term cognitive problems and death. Because the quiet, hypoactive form is often missed, ICU nurses screen every patient with a validated tool, usually the CAM-ICU or the ICDSC, after checking the level of sedation. A positive screen triggers a search for reversible causes and a review of drugs, not a sedative by reflex. Ward-level delirium care has its own page; this page covers screening and prevention in the ICU.

Reference values

  • Two validated ICU tools: CAM-ICU (a short bedside assessment) and ICDSC (a checklist across the shift). The unit uses one, at the times its protocol sets, and after any sudden change.
  • Types: hyperactive (agitated, restless, emotionally labile) and hypoactive (less responsive, withdrawn, apathetic).
  • Risk factors: older age, prior cognitive impairment, sedatives (especially benzodiazepines) and opioids, mechanical ventilation, untreated pain, immobility, sleep loss, sepsis, anaemia, abnormal blood pressure.
  • Common triggers to look for: infection, low oxygen, electrolyte or glucose changes, drugs (sedatives, anticholinergics), alcohol or drug withdrawal, severe sleep loss.

What you need

  • The sedation scale result for the same moment.
  • The unit's delirium tool and its record.
  • Glasses, hearing aids, a visible clock and calendar.

How to measure it (and why)

  1. Measure sedation first: if the patient does not respond to voice, record deep sedation or coma and reassess later.
  2. Screen with the unit's tool at the set times and when behaviour changes: delirium fluctuates, so one normal check is not enough.
  3. Compare with the patient's baseline, asking the family how the person usually thinks and behaves: an acute change is the key feature.
  4. Report a positive screen the same shift: the team looks for reversible causes and reviews the drugs.
  5. Check the common triggers you can see: oxygen saturation, glucose, temperature, pain, signs of withdrawal.
  6. Reorient often and give back glasses and hearing aids: they reduce disorientation.
  7. Protect sleep: light that marks day and night, a clock and a calendar; sleep hygiene is one of the prevention measures recommended.
  8. Mobilise early with the team and invite the family to take part: these are the measures with the most support.

How to read it

  • A calm, sleepy patient can have delirium: a negative RASS with a positive screen is hypoactive delirium.
  • A positive screen is a sign of brain dysfunction, like a vital sign: report it as you would a fall in blood pressure.
  • Evidence that antipsychotics prevent or treat ICU delirium is weak; medicines are a team decision, not a first response.
  • Delirium in a patient who has recently stopped alcohol may be withdrawal: tell the team, which decides on the withdrawal protocol.

Next step: when to call for help

  • Call at once: new delirium with low oxygen, fever, low glucose, a new neurological sign, or a patient at risk of pulling out the tube or lines.
  • Report the same shift: a new positive screen, a fluctuating level of attention, or signs of alcohol withdrawal.
  • Record the result each shift, even when negative: the trend is what the team uses.

Test yourself

Think of the answer, then tap the question to see it.

Why is the sedation level checked before screening for delirium?

A patient who does not respond to voice, deeply sedated or in coma, cannot be assessed; that state is recorded and the screen repeated later.

What four features does the CAM-ICU assess?

An acute change or fluctuating course, inattention, disorganised thinking and an altered level of consciousness.

Which type of delirium is most often missed?

Hypoactive delirium: the patient is quiet, withdrawn or drowsy and does not draw attention.

Which preventive measures have the most support in the ICU?

Multicomponent bundles, especially those that include early mobility and family participation.

Add to my cards (4)

Connections

← All of nursing

Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order.

Sources: The ABCDEF Bundle in Critical Care (Marra A, Ely EW, Pandharipande PP, Patel MB) (Critical Care Clinics, author manuscript in PubMed Central, 2017); Delirium (Medical Encyclopedia) (MedlinePlus, U.S. National Library of Medicine, 2025); A systematic meta-review of interventions to prevent and manage delirium in the Intensive Care Unit: Part 2, non-pharmacological and multicomponent interventions (Kundakci B et al.) (Critical Care, PubMed Central, 2025).

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Representative model, for educational purposes only.