How ACE-T was made

The question after the screen

A nurse completes a delirium screen and the result is positive. The next question is practical: what should happen now, and who should do it?

Delirium care has three parts: detection, treatment and prevention. Tools for detecting delirium are well established, and so are approaches to preventing it. Treatment is much less clearly defined. Guidelines and other sources describe a package of actions, such as finding and addressing triggers, managing symptoms and supporting recovery, but they differ a great deal in what that package contains.

Even the name varies. In guidelines, delirium treatment appears as:

• multicomponent non-pharmacological interventions
• a multicomponent program
• non-drug strategies
• established pathways of good care

The content ranges from two brief recommendations to a programme of 15 components.

Who does what, and when

The manuscript’s review found that most guidelines did not specify which professional group was responsible for which action. Two went further. The American Psychiatric Association’s 2025 guideline notes that nurses “deliver or assure delivery” of most non-drug interventions. The German S3 guideline places the urgent medical work-up with specialist physicians, and allocates non-drug care to nursing, occupational therapy and physiotherapy by problem area.

Neither specifies the order or timing of what nurses should do in the hours immediately after a positive screen.

Outside guidelines, research studies, textbook chapters, order sets and clinical pathways vary in the same ways: sequence, timing, documentation, and which discipline does what. As a result, clinical teams vary in how they respond to a positive screen. Studies have found gaps in identifying triggers that could be reversed, in assessing and managing distress, and in telling patients and families about the diagnosis. Several have found gaps in escalation and action after positive screens.

Start with the nurse

In many health systems, nurses carry out most delirium screening. They can therefore respond promptly to a positive screen. They also carry much of the ongoing care: managing interventions, monitoring distress, talking with families and keeping patients safe.

The idea for ACE-T came from two Edinburgh clinicians: Alasdair MacLullich, a geriatrician at the University of Edinburgh who developed the 4AT, and Maggie Higgins, a nurse in Medicine of the Elderly at the Royal Infirmary of Edinburgh. They wanted a short, practical tool for the first steps after a positive screen, one that nurses could start straight away and that would complement the medical and wider team roles.

A practical nurse-focused tool is needed to guide the first steps after a positive screen.

From the introduction to the ACE-T paper.

Multidomain treatment

The ACE-T paper uses the term multidomain delirium treatment for the whole package of actions involved in treating delirium in routine care.

The term avoids splitting treatment into “non-pharmacological” and “pharmacological” parts. Guidelines advise against giving psychotropic drugs routinely, and allow brief, targeted use for severe distress that other measures have not relieved, or for safety. Medicines are therefore one optional part of a wider set of actions. The term also separates a package of care from single interventions, such as a particular drug or music.

ACE-T is a nurse-led tool for the first part of multidomain treatment.

Drafting the tool

Alasdair MacLullich and Maggie Higgins drafted the provisional tool with Alexandra Cours of Stanford University School of Medicine and Johannes Trabert of AGAPLESION Markus Krankenhaus in Frankfurt. They drew on published delirium guidelines and clinical care standards, on the structure of the multidisciplinary TIME bundle (Triggers, Investigations, Management and Engagement), and on their own clinical experience.

They grouped the first nursing actions into three domains, and the name comes from them.

From the start, ACE-T had defined limits. It prompts nurses to consider observations, to check whether clinically indicated investigations and a medication review have happened, to assess distress and the care environment, to document delirium, and to communicate with the clinical team and the family. It does not require nurses to diagnose the cause or order investigations outside local policy, and it does not replace wider multidisciplinary care.

Early drafts were revised after nurses and physician colleagues commented on the layout and content.

Asking the people who would use it

Before ACE-T was used with patients, local investigators at the three hospitals asked nurses, physicians, physician associates and assistants, and nurse practitioners to review the provisional tool and fill in an anonymous paper survey. Fifty-three people took part: 26 nurses, 19 physicians and 8 advanced practice providers.

The ratings were encouraging, and the criticism was useful. Twenty-one of 52 respondents (40%) said at least one section was unclear or difficult, and 22 wrote suggestions. Their comments kept returning to the same points:

• Make the line between nursing and medical actions clearer, especially in Acute Triggers.
• Simplify Acute Triggers for a busy shift.
• Fit ACE-T into existing documentation, so nothing is written twice.
• Add more person-centred prompts to Patient Experience.
• Phrase each item as a question or an instruction.

Of the 22 people who wrote comments, 5 raised uncertainty about medication review, 5 about where diagnostic work-up and ordering blood tests should stop for nurses, 4 about Acute Triggers in general, 4 about the layout, and 3 about NEWS2 or the QDAT.

Three hospitals, three ways of working

Each hospital introduced ACE-T through its own clinical teams. There was no shared training package or standard procedure, so each site used its own approach.

Working in three health systems showed differences in professional scope, terminology, workflow and documentation that a single site might have missed. One example is how comfortable nurses are writing “delirium” in the notes rather than “? delirium”. ACE-T allows either.

In Edinburgh, the investigators felt that the tool’s explicit nursing focus and simple format helped local teams engage with it.

What the records showed

At each hospital, local reviewers looked at 10 records from before ACE-T was introduced and 10 from after: 60 records in all. Each had a positive delirium screen or a documented diagnosis of delirium. Reviewers noted which care actions were documented in the 48 hours after the first positive screen.

The clearest pattern, seen at all three hospitals, was whether delirium itself was written down.

Other items were more mixed. Documented distress assessment rose in Stanford (3 of 10 before, 10 of 10 after) and in Frankfurt (4 of 10 to 6 of 10), but fell in Edinburgh (9 of 10 before, 7 of 9 after). Informing the patient or family, and giving a leaflet, varied between sites.

Vital signs and blood test review were already recorded in almost every Edinburgh and Stanford record before ACE-T. In Frankfurt, the baseline records came from the delirium team rather than the full ward notes, so the low baseline figures there are likely to reflect, at least in part, which records were reviewed.

What comes next

The paper recommends a prospective feasibility study. Researchers would design the implementation with bedside nurses, patients and carers; look at how ACE-T fits with the work of other disciplines; formally assess content validity and usability; and include consecutive eligible patients rather than a selected sample.

It would measure reach, uptake, completion within four hours, fidelity, staff workload, acceptability, communication with patients and carers, and unintended consequences. It would also test whether an electronic version reduces duplicate recording without adding alerts or paperwork. That groundwork would make it possible to test clinical effectiveness.

The authors describe ACE-T as a promising, practical tool for the initial nursing response to delirium, and a starting point for teams who want those first steps to be clearer and more consistent in routine care.

1. DraftingProvisional tool, called ACE-T-N, drafted by clinicians in Edinburgh, Stanford and Frankfurt.
2. Staff review53 staff rate the provisional tool and suggest changes; the tool is revised before clinical use.
3. Summer 2025Baseline records reviewed at the three hospitals.
4. Autumn and winter 2025 to 2026ACE-T in use; records reviewed after introduction.
5. 2026Development and pilot paper submitted for publication.

The authors

The authors thank the colleagues who took part in the survey and in introducing ACE-T at each site.