Article Text

POSTOPED: improving surveillance of postoperative delirium in a Scottish tertiary hospital
  1. Keiran Anthony Brown,
  2. Alison McCulloch
  1. Surgical Acute Frailty Team, NHS Tayside, Dundee, UK
  1. Correspondence to Dr Keiran Anthony Brown; keiran.brown2{at}


Delirium is the most common postoperative complication among patients over the age of 65 years. It is associated with increased morbidity and is a significant financial cost to healthcare systems.

We aimed to improve the detection of delirium on the surgical wards of a tertiary surgical centre. This would take the form of completion of 4AT assessments (the 4 AT test for delirium, on admission and 1 day postoperatively). Prior to this project, the 4AT was in use in the surgical admission clerking paperwork for over 65 s, however, 4AT assessments were not routinely performed as part of day 1 postoperative assessment. By introducing routine postoperative assessment and reinforcing the importance of admission assessment, we hoped to allow for objective comparisons to be made about patients cognitive state and thereafter improve delirium identification.

After a baseline snapshot data collection period, we conducted five (Plan, Do, Study, Act) cycles following which repeat snapshot data were collected. Improvement strategies included ‘tea-trolley’ teaching sessions, adhesive 4AT pro-forma, targeted accompaniment of specialty ward rounds with reminders to complete 4AT assessments and working with nursing staff to promote awareness of delirium among permanent non-rotating healthcare professionals.

For the admission 4ATs, completion improved from a baseline of 74.1%–90.5% in cycle 5. Completion of postoperative 4AT assessments rose from 14.8% at baseline to 47.6% in cycle 5.

We were able to improve the use of a delirium screening tool, (the 4AT) among the postoperative elderly population in this centre via the use of regular teaching sessions, targeted interventions on ward rounds as well working with non-rotating staff. Further improvements could be made by widening access to delirium champion programmes and including delirium as an outcome measure of national surgical audits such as the National Emergency Laparotomy Audit.

  • Diagnosis
  • Quality improvement
  • Geriatrics
  • Surgery
  • Postoperative Care

Data availability statement

Data are available on reasonable request.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Delirium is the most common postoperative complication in over 65 s yet it is underdiagnosed in part due to its hypoactive forms. In response to increased referrals for delirium to the surgical frailty service, a 4AT-based assessment system was instituted in postoperative patients to aid delirium detection.


  • This quality improvement project successfully improved postoperative monitoring in the absence of physical bundle forms in the surgical environment.


  • Continued use of such low-cost surveillance measures, perhaps within national surgical audits, could provide the data and recognition required to enable targeted interventions and research into perioperative causes of delirium.


This project was started after a newly established service within NHS Tayside, the Surgical Acute Frailty Team (SAFT), had noted a considerable number of their referrals were for support with management of delirium in postoperative patients. This was despite the availability of management bundles such as the TIME1 bundle and guidelines by the National Institute for Health and Care Excellence.2 3 It was apparent that knowledge of investigation and management of delirium was lacking.

This project was undertaken at Ninewells Hospital, a tertiary care hospital with five inpatient acute surgical wards. NHS Tayside covers a population of approximately 400 000 people,4 and in 2018–2019, it performed 7019 emergency operations across all surgical specialties.5 At the inception of this project, the 4AT,6 a screening tool for delirium, had been embedded into the acute admission clerking documentation for elderly patients (ie, aged ≥65 years of age), but there had been no systematic follow-up of its use, and whether patients had been assessed for delirium postoperatively. This is despite British Geriatrics Society (BGS) guidance that recommends daily 4ATs for surgical inpatients over the age of 65.7

Preintervention snapshot data showed that 74.1% of elderly inpatients underwent 4AT assessments on arrival to the acute surgical admission unit; of these 15% were identified as delirious (4AT score ≥4). Only 14.8% of all elderly patients went on to receive postoperative assessments for delirium, of which 50% of these assessments identified delirium. The inference we drew was that assessments were being done when attention was brought to medical staff that a patient was ‘confused,’ which in discussions with ward staff proved to be the case.

This behaviour is reactive in nature, rather than the proactive approach that professional guidelines recommend.7 This approach risks missing many patients with delirium, and some literature estimates that 60%–66% of delirium diagnoses are missed,8 9 due partly to hypoactive forms of the syndrome. We wished to change the reactive process that seemed to be happening on the wards, with a proactive one.

From conversations with staff, it was recognised that several barriers existed which prevented this. Namely that, 4AT assessments would take too long on busy surgical ward rounds and that staff were simply not aware that such guidance existed (not surprising given the cited guidance from the BGS was first published in 2021). We aimed to change these views and create an environment where assessment was easier to perform, and in this way improve compliance to perioperative care guidelines. When such monitoring was achieved, further projects could focus on specific management of delirium itself, via bundles such as the TIME bundle1 and our own POSTOPED bundle (see online supplemental figure 5).

Supplemental material

Supplemental material

We collected data for this project on the inpatient ‘postoperative’ surgical wards, however, some interventions were implemented on the admission ‘preoperative’ wards (see online supplemental figure 4) both settings during their rotations within the department. This project ran from April 2021 to December 2021.

Supplemental material

Our SMART aims were.

  1. Increase the proportion of elderly (those aged ≥65 years) operative patients who had an admission 4AT assessment from 74.1% to 95% by December 2021.

  2. Increase the proportion of elderly operative patients who had a day 1 postoperative 4AT assessment from 14.8% to 50% by December 2021.

These two aims were formed to produce a situation where an individual patient would have a ‘baseline’ cognitive assessment on admission and a ‘repeat’ cognitive assessment in the postoperative period. Enabling objective comparison for an individual patient across their hospital stay, in an environment where multiple ward changes are common early in the patient journey.


Delirium is an acute fluctuant confusional state composed of a disturbance in attention and awareness that is a change from the baseline cognition.9–12 The criteria for delirium make clear that for such a diagnosis, there must be evidence that the presentation is of a ‘direct physiological consequence’ of another medical condition or state. As a syndromic classification, delirium has a broad definition, and many precipitating factors of ‘physiological consequence’ have been identified, yet it is usually multifactorial.13 Several of these physiological antecedents are frequently encountered in the surgical environment.

Delirium is the most common surgical complication among those aged above 65 years of age.14 15 In 2018, 25% of all hip fracture repair patients in England met the diagnostic criteria for delirium.16 Such a diagnosis adversely affects patients; a study of Canadian postoperative elderly patients found that those that met the diagnostic criteria for delirium spent on average 7.4 days more in hospital than those without, at a cost of $C1 million.17 Delirium contributes significantly to mortality.18 A US Medicare claimants study19 found that it was associated with increased mortality risk relative to controls up to 12 months post index presentation. Though commonly associated with an acute cognitive deficit, delirium appears to be influential in subsequent long-term cognitive decline, with a pathological mechanism distinct from dementia and age related cognitive impairment.20 21

The TIME1 bundle was developed for use within the AMU (Acute Medical Unit) department at North Middlesex Hospital as both a surveillance and management strategy for delirium. Using an improvement strategy of staff education and practical aids for the ward environment, they had notable success in increasing the use of the 4AT from 40% to 61% within one Plan, Do, Study, Act (PDSA) cycle. Since then, the TIME bundle has seen support among care of the elderly departments across the UK and has been taught at medical schools. Seeing the proliferation of this project, we sought to adapt their methods to the surgical environment and attempting some of their further recommendations, in particular the use of frailty link nurses. Adaption of delirium education materials to environments other than medical wards has precedent, with a quality improvement project involving the Greater Manchester Critical Care Network showing improvement in the use of screening tools.22


Data for this quality improvement project were collected in a series of six ‘snapshots,’ totalling 149 patients, between March 2021 and November 2021. The first snapshot, ‘baseline,’ was taken on 26 March 2021. In each intervention cycle, a planning meeting would occur, actions would thereafter be taken, and then approximately a month following said action a data snapshot of current progress to our aims would be taken.

Data collection snapshots were collected on 22 June (cycle 1), 30 July (cycle 2), 4 September (cycle 3), 18 October (cycle 4) and 25 November 2021 (cycle 5).


All patients on the acute surgical wards aged 65 years or above at the time of admission that had undergone surgical management while in hospital and were at least 1 day postoperative. Those with prior cognitive impairment were included, as this is a significant risk factor for delirium.23 Surgical management was defined as having undergone an operative or endoscopic procedure while in hospital. This included interventional radiology procedures and endoscopic retrograde cholangiopancreatography.


All patients under the age of 65 years were excluded. Elective surgical patients were excluded. Orthopaedics patients were not included. The elective surgical ward in the study hospital had a different management pathway, with a different route of admission, and therefore, the decision was made to exclude elective patients. Orthopaedic patients often did not share a common admission pathway and were therefore excluded for similar reasons. We excluded all patients where 4AT was not completed due to inability to engage due to reasons of language or consciousness (n=0).

Data collection

Patient sex, age, parent surgical specialty and procedure data were collected. Data were collected on whether patients had had a 4AT score completed on admission and whether this had been repeated at least 24 hours postoperatively. The raw 4AT scores were collected, and these were then evaluated to determine the percentage of positive (ie, greater than or equal to 4) scores in each snapshot sample. From the third snapshot onwards, data were also collected on uptake of the use of 4AT test stickers, the use of which is expanded below.


The main intervention was the use of ‘tea-trolley’ teaching sessions (teaching slides are found in online supplemental figure 6). Recognising the time pressures of medical and nursing staff to attend formalised teaching sessions, the SAFT conducted short 5–10 min teaching sessions within doctors’ rooms on the surgical floor wards in which we were trying to promote change along with providing snacks and drinks as an incentive. At the launch of the project, we conducted a similar session to senior surgical colleagues at a grand rounds ‘clinical effectiveness meeting’ in April 2021.

Supplemental material

With presentations in smaller groups for shorter periods, we hoped to strengthen audience engagement over more didactic lecture theatre-based methods. Such sessions would also act as reminders for the resources made available to staff, such as the THINK delirium toolkit,24 25 patient information leaflets, delirium management guidelines and in later cycles, the use of 4AT assessment stickers. By improving the interactive nature of our education, we reasoned that this would promote increased compliance to our audit standard and lead to improved delirium surveillance.

From the third snapshot cycle onwards, we introduced adhesive 4AT tools. Evaluating previous interventions seen for peripheral venous catheter bundles26 and surgical handovers, we felt that the use of detailed documentation paperwork could prove obstructive to our aims of promoting a quick, easy and effective screening tool. We, therefore, supplied all intervention wards with 4AT assessment ‘checkbox like’ stickers (online supplemental figures 2 and 3), enabling clear and speedy documentation of delirium screening. These were placed on medical notes trolleys on the wards to enable ease of access on ward rounds.

Supplemental material

Supplemental material

Additional interventions included accompanying specialty ward rounds, engagement with frailty link nurses and highlighting in departmental meetings to surgical colleagues the prevalence and importance of postoperative delirium. We noted a few issues with our planned interventions at the outset of this study. First was the issue of engagement with all ward staff. We noted that despite our best efforts, it would not always be possible to reach all ward staff on our teaching days. Therefore, we aimed to complete sessions in the period after lunch, at the time of the ‘back’ shift starting. Consequently, our tea-trolley sessions would be to wards at the highest staffing levels during the day in a period where much of the ward work had been completed and staff had had their lunch breaks. This we reasoned would optimise engagement with, and reach of, our sessions. We also widened our education activities in later intervention cycles to non-rotating staff such as nurses.

Second, the issue of whether to use a ‘bundle form’, à la checklist manifesto culture.27 A trend in the production of quality improvement project checklists and forms was noted at the commencement of this project. Considering the NHS (National Health Service) paper-lite strategy, and being keen to streamline our approach to assessment, we deliberately did not produce a bundle-like A4 sheet form for staff to fill. While this may initially make improvement harder to implement without objective, clear and deliberate forms to take note of, we deemed this a more sustainable design, as by implementing a culture of assessment independent of material resources, surveillance would occur when said forms were not available, and thus survive the duration of the quality improvement project.

The SAFT consists of a consultant geriatrician, a specialty doctor, one advanced nurse practitioner and one clinical fellow. Our intervention sessions involved the use of resources that were easily replicable, consistent in their messaging and could be delivered by all levels of the multidisciplinary team. SAFT consists of permanent, non-rotating staff, who have regular contact with the intervention wards via regular ward rounds and reviews. We, thus, deemed our interventions to be sustainable.


At the outset of this project, we spoke informally to ward staff, and SAFT discussed their experiences with referrals to their team for delirium advice in design meetings. We took a baseline snapshot set in March 2021. Following this, we conducted five PDSA cycles.

PDSA cycle 1

We delivered the first of our interactive tea-trolley sessions across all five surgical wards and put-up copies of our POSTOPED mnemonic poster (see online supplemental figures 5 and 6) within doctor’s rooms. This achieved an increase in admission 4ATs of 8.5% and an increase of postoperative 4ATs of 2.6%. We reasoned that not all staff had been reached by our interventions so sought to repeat teaching to staff in the following cycle and further signpost resources. In meetings with doctors and in discussions among SAFT, we sought to make documentation of the 4AT easier in the time-pressured environs of a surgical ward round. To this end, we decided to implement the 4AT assessment adhesive tool.

PDSA cycle 2

We repeated our tea-trolley sessions, this time making sure to hit the key time of approximately 15:00 hours, when backshift staff started, and all other staff had had their breaks. This led to a decrease of admission 4AT completion percentage by—5.3% compared with PDSA 1 but still an increase of 3.2% on baseline. 4AT postoperative completion increased by 14.4% from PDSA 1, 17.0% from baseline. Such findings gave confidence to the notion our initial PDSA teaching had not circulated widely enough. However, uptake of the 4AT adhesive tool was poor, with none being used on postoperative patients.

PDSA cycle 3

For the third cycle, we noted that the rotation of junior medical staff was due to occur in the first week of August 2021. Therefore, we ensured that our teaching session was included in the induction programme for junior doctors. We noted that the adhesive 4AT tools were not being used and so we moved them from the doctor’s room to the ward round notes trolleys, envisaging that they would be better used if on hand during twice daily ward rounds. 4AT admission completion increased by 2.7% from the previous cycle, an increase of 5.9% from baseline. Postoperative 4AT completion percentage was—18.5% on the previous cycle, −1.5% on baseline.

PDSA cycle 4

It was apparent that relying on rotating foundation trainees would not produce the sustainable improvements required, as those regularly prompted to complete assessments left the wards to new clinical rotations. In our next cycle, therefore, in addition to promoting the adhesive stickers and running tea-trolley sessions for medical staff, we expanded the scope of our interventions. Noting that most of our snapshot patients were vascular patients, the SAFT team accompanied the vascular ward round weekly, prompting 4AT assessments in postoperative patients. Postoperative delirium was also raised as a prevalent complication at formal and informal meetings with the surgical senior team. 4AT admission completion percentage rose by 4.6% from the previous cycle, 10.6% on the baseline. 4AT postoperative completion percentage rose by 9.7% on the previous cycle, 8.3% on the baseline percentage.

PDSA cycle 5

Rationalising that several members of staff we were aiming to educate were brand new to the NHS we felt that our efforts would be best directed on fostering stronger relationships with the frailty link nurses, ward charge nurses and emphasising good practice on select ward rounds. We also performed another teaching cycle. 4AT admission completion percentage rose by 5.9% on previous, giving a final percentage improvement of 16.4% from baseline (74.1%–90.5%). Postoperative 4AT completion rose by 24.5% on the previous cycle, 32.8% from baseline (14.8%–47.6%). 4AT stickers were not used at all during this cycle.


The results are summarised above in table 1. Line charts for the SMART aims of this project are shown in figure 1 . Figure 2 is a run chart showing changes from the baseline completion percentages.

Table 1

Cycle by Cycle Project Data

Figure 1

Percentage of patients that underwent 4AT assessment on admission and at least day 1 postoperatively within each of the snapshot cycles. The SMART aims of the project were for 95% of patients to be assessed on admission (blue) and 50% of patients to be assessed at least day 1 postoperative (red) by the projects end.

Figure 2

This graph illustrates the improvement in 4AT completion percentage from the baseline percentage prior to interventions. Positive percentages indicate improvement, negative percentages indicate fall in 4AT completion compared to baseline. PDSA, Plan, Do, Study, Act.

Snapshot patients were majority male in five out of six snapshot cohorts, the mean age was 76.5 between across all six snapshot cohorts, with each cohort being within 1 SD of this average and each other cohort. Vascular contributed the most patients of the three specialties in four out of six of the cohorts with general surgery contributing the most in two snapshots.

From the baseline snapshot cohort to the final cycle (cycle 5) in December 2021, the percentage of patients who had a complete admission 4AT assessment rose from 74.1% to 90.5%, a rise of 16.4%, this was below our stated SMART goal of 95% (see figure 1).

From the baseline snapshot cohort to the final cycle (cycle 5) in December 2021, the percentage of patients who had a 4AT assessment at least 1 day postoperatively rose from 14.8% to 47.6%. This was below our stated SMART goal of 50% (see figure 1).

Improvements were seen across a 6-month period both for ‘on-the-door’ admission assessments and postoperative assessments.

The percentage of those who were positive for delirium (a score of 4 or greater) was never greater than 15% on admission, and always above 30% postoperatively. Noting that much larger data sets in hip fracture patients have found prevalence of delirium at 25%,16 this may suggest a remnant of selective testing in some patients. Of note is that the lowest prevalence of delirium postoperatively was found in cycle 5, where screening was at its highest.

The use of the adhesive 4AT assessment tools saw poor uptake, the use of them in cycle 5, where postoperative 4AT assessments were at their highest, was completely absent. Suggesting the improvements observed were independent of the implementation of this intervention.

The postoperative 4AT completion percentage sharply fell in cycle 3. This cycle occurred at the point of the foundation trainee changeover in August, where the new foundation year 1 trainees were inducted to the wards.

Lessons and limitations

Our findings suggest that a combination of regular education and training, involvement of the multidisciplinary team as well as targeted intervention in areas of high prevalence of our problem of interest was effective in producing progress towards the project aims.

As stated in our design, we wished to promote a delirium surveillance culture. Our changes, and their effects, would not be rooted in material resources but rather in the altered awareness of professionals to a common postoperative complication. Improvements were seen despite, rather than due to, the introduction of 4AT assessment stickers on the wards, where uptake was virtually absent. In crowded ward environments full of paper forms and limited space to place them, we could not account for instances where on-ward staff overrode our strategic placing of resources.

We did not survey medical or nursing staff on their use of the 4AT adhesive tools, this could have been something we completed after the first cycle of their introduction to further understand their reception and better use them. We also did not survey those who received teaching via our tea-trolley sessions to see the reach of our teaching sessions, which would have enabled objective assessment of efficacy of the sessions and the number of staff reached.

Later in the project, we focused our efforts on vascular patients, as they were a plurality within the snapshot cohorts. The vascular surgery department has smaller number of medical staff but a significantly comorbid and frail patient population. SAFT did not have the resources to accompany every surgical ward round, but focusing on the particularly morbid population, dialoguing directly with the small number of medical staff responsible for their care we reasoned we could have a significant impact. This appears to have been the case noting significant incremental increases in compliance to our standard following these interventions. Targeted interventions were, therefore, a particularly effective strategy.

We found a significant reduction in compliance following one of our cycles due in part to the influx of medical staff new to both the NHS and the surgical department. We tried to counter this by including nursing staff in our interventions, with surgical advance nurse practitioners and frailty link nurses who delivered teaching sessions and disseminated reminders to nursing staff. This could be improved on, however. Previously, the Royal College of Nursing ran a CPD (continuing professional development) scheme called ‘delirium champions’28 which educated nurses on recognising delirium in their patients and beginning initial assessment via the 4AT. Future interventions could include reinstitution of such a scheme locally, with accompanying remuneration/portfolio recognition for revalidation purposes. This could help to incentivise uptake as it would avoid such a scheme as being seen as an ‘extracurricular’ process, and instead be one which would be part of one’s normal workload, making it easier to staff to learn and engage with the material within.

Our focus in this project was on surveillance with acute inpatients. We did not assess the efficacy of interventions for our 4AT positive patients. Although we had produced a surgically orientated management strategy in the POSTOPED bundle poster, given that surveillance was so poor postoperatively at the outset of this project, we felt that this would be a step for the future. Once regular monitoring for delirium was in place, we would be better placed to introduce surgically targeted delirium management schemes, and thus be able to follow in separate projects, whether, for example, pain and analgesia had been appropriately reviewed.

Of note is that delirium is an outcome measure in the National Hip Fracture database as a postsurgical complication.16 This project was conducted in a single centre, however, a top-down approach could also be of benefit, as it is noted that the National Emergency Laparotomy Audit does not include delirium or 4AT surveillance as an outcome measure,29 despite the procedure encumbering similar delirium antecedent factors. Such a change could highlight the awareness that delirium needs in the surgical environment. Locally, SAFT collects data on delirium in the frail postoperative patients to review outcomes and to improve care of patients with delirium.

Our approach was labour-intensive and reliant on regular teaching sessions. This could not continue indefinitely. Going forward, such sessions would be conducted 4 monthly for junior medical staff during induction periods with frailty nurses providing sessions for nursing staff at similar intervals. Towards the end of this project, several specialties in this centre were migrating to electronic note platforms (in this case eKORA), where specific types of entry form exist for different clinical encounters (such as uploading of operation notes, admission forms and certification of death). A specific postoperative review form which would require the 4AT to be filled in before submission, was discussed as a possible further intervention once the surgical departments had migrated to this system, as it was felt an electronic system would make completion easier. This migration has not yet occurred.


In summary, delirium is the most common postoperative complication in the elderly and is significantly underdiagnosed and recognised. Medical staff should assess patients with a specific and sensitive validated scoring tool, the 4AT, on admission and 1 day postoperatively (to allow for the wearing off of anaesthetic). Doing so will enable earlier recognition of potential triggering causes as well as earlier treatment, and thus reduce mortality and morbidity due to both delirium and its associated effects. The 4AT is ideal for this as it is a short tool, which is easy to train staff to use appropriately and is sensitive and specific for delirium.

During this project, we educated staff in the use of the 4AT and promoted awareness via reminders both on ward rounds and via poster media. We had begun to form a network of staff to continue our work, but further action is required with top-down interventions via inclusion of delirium surveillance in national audit schemes and consideration of funding for accredited CPD schemes. This project was incredibly valuable as a learning experience and should provide the launchpad for several further improvement projects to build on the progress made.

Supplemental material

Data availability statement

Data are available on reasonable request.

Ethics statements

Patient consent for publication


The authors wish to acknowledge all staff in the Surgical Acute Frailty team for their input and comments at various stages of this project. They wish to acknowledge Vicki Tully, teaching lead for patient safety at NHS Tayside, for her assistance with practicalities of publication and providing feedback on an early draft.


Supplementary materials


  • Contributors KAB collected data, performed interventions such as tea-trolley teaching sessions, designed the POSTOPED poster, collected data, analysed data and produced the manuscript drafts. KAB drafted the response to peer-review comments and edited the returned manuscript. AM collected data, performed interventions, including tea-trolley teaching, contributed edits to the manuscript and contributed feedback edits to the POSTOPED poster used in interventions. AM reviewed the response to peer-review comments and the edited manuscript. KAB is the guarantor of this study.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.