The Preventing of Postoperative Delirium
A Prospective Intervention With Psychogeriatric Liaison on Surgical Wards in a General Hospital
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Background: Delirium is a common complication in elderly hospitalized patients. It prolongs the length of hospital stay, raises costs, increases the workload of the nursing staff, and may necessitate transfer of the patient to a nursing home. The risk of postoperative delirium is particularly high in elderly patients with pre-existing cognitive deficits.
Methods: In an open study, we systematically assessed the frequency of postoperative delirium in patients over age 70 on two surgical wards of a general hospital. In a six-month “prevalence phase,” from March to August 2011, we counted the number of patients with postoperative delirium, but did not initiate any intervention. Thereafter, in a ten-month “intervention phase” from September 2011 to June 2012, a nurse with special training in the management of delirium carried out an intervention involving component measures of the Hospital Elder Life Program (HELP) on one of the two wards, with the aim of preventing postoperative delirium. The patients on the other ward served as a control group.
Results: In the prevalence phase, 20.2% of all patients developed postoperative delirium (95% confidence interval [CI], 14.6–26.4). In the intervention phase, postoperative delirium arose in 20.8% (95% CI, 11.3–32.1) of the patients on the ward with no specific interventions, but in only 4.9% (95% CI, 0.0–11.5) of those on the ward where the intervention was carried out. The difference was presumably due to the measures initiated by the specially trained nurse, including validation, improvement of sleep, cognitive activation, early mobilization, improved sensory stimulation, and improved nutritional and fluid intake. Important predictors of postoperative delirium included a low score on the Mini–Mental State Examination, advanced age, and preoperative infection.
Conclusion: The frequency of postoperative delirium in elderly patients with cognitive deficits can be lowered with nursing measures carried out by a specially trained nurse, close postoperative supervision, and cognitive activation.
With an incidence of 14% to 56%, delirium is the commonest complication in over 70-year-olds receiving treatment as inpatients (3), and is associated with a mortality rate of 25% to 33% (4). Dementia increases the likelihood of delirium, and is far and away its most important risk factor (5). Especially in medical and surgical wards and in intensive care, 50% of all patients are disoriented postoperatively (6). Delirium increases the length of hospital stay, the costs, the amount of care required, and the risk that the patient will be institutionalized (7–10).
In the past few years in Germany, some promising pilot projects have shown that the incidence of postoperative delirium on general hospital medical and surgical wards can be reduced by a variety of interventions (11–14).
Existing models, such as the procedures used at the St Franziskus Hospital in Münster, show that the incidence of postoperative delirium can be reduced if the patient has a single defined contact person for the duration of their hospital stay and is screened on admission for cognitive deficits (15, 16).
Non-medical interventions are important supportive elements of treatment that are not adequately utilized in the everyday management of delirious patients (17, 18). They include aids to orientation: a clock, a calendar, or a familiar photo can all have a supportive effect in the patient’s treatment. Protecting patients from stimuli is an important aid in non-medical treatment of delirium. This should include not changing the patient’s room and having no staff changes, so far as possible. Sensory aids for the patient such as glasses or hearing aids should be used. Adequate lighting is important, so that a proper sleep-wake cycle is ensured. Personal attention and the involvement of friends or relatives have a positive effect (19–21).
The aim of the present study was to answer the following questions:
- What is the incidence of postoperative delirium in a general surgical ward in a general hospital?
- What preoperative factors are predictive of delirium?
- Can a specialist geriatric psychiatric nurse reduce the incidence of postoperative delirium by means of non-pharmacological interventions?
The present study is something of a new departure in that the focus was, first, on cognitively impaired patients undergoing general surgical treatment in the context of a real-life mixture of patients, and, second, on non-drug, nursing interventions. We aim to show that delirium prophylaxis is not primarily a task for surgeons or physicians, but for trained nursing staff.
The methods used, especially the statistical analysis, are described in detail in the supplementary eMethods section.
The study was carried out in two general surgical wards of a teaching hospital providing standard care; one was designated the intervention ward and the other the control ward. A variety of medical and ancillary teams were responsible for patients’ treatment. The patient groups had similar demographic characteristics. The treatment teams were made up of surgeons, specialized surgical nurses, physiotherapists, and social workers. The two wards were similar in terms of numbers of nursing and medical staff per number of beds. In neither of the wards was there any special training in geriatrics or geriatric psychiatry.
During the first phase of the study (prevalence phase; March to August 2011), on both wards the number of over 70-year-olds who already showed cognitive impairment and confusion preoperatively was recorded. Socioeconomic data, diagnoses, physical diseases, and preoperative medication were also recorded. In addition, the following investigations or measurements were carried out pre- and postoperatively:
- Mini–Mental State Examination (MMSE) (22)
- Activities of Daily Living (ADL) (23)
- Confusion Assessment Method (CAM) (24)
- Delirium Rating Scale (DRS) (25)
- Nurses’ Observation Scale for Geriatric Patients (NOSGER) (26)
- Barthel Index (27)
- Montgomery–Åsberg Depression Rating Scale (MADRS) (28)
- Body mass index
- Hours of sleep (Table 1).
During the subsequent 10-month intervention phase of the study (September 2011 to June 2012), one of the two wards became the intervention ward, the other the control ward.
On the intervention ward, interventions were implemented in the following areas by the geriatric psychiatric nurse (delirium liaison nurse) pre- and postoperatively, according to the individual needs of the patients (Table 2):
- Early mobilization
- Improved sensory stimulation
- Improved fluid and nutritional intake
- Non-drug sleep improvement
- Cognitive activation
- Validation (29, 30).
The study included all patients admitted to the two surgical wards between March 2011 and June 2012, so long as they fulfilled the following criteria:
- Over 70 years of age
- No clinically manifest signs of delirium
- Capable of understanding the study and consenting to participation.
Patients with any of the following characteristics were excluded:
- Advanced dementia, unable to give consent
- Severe delirium preoperatively
- End-stage disease
- Refusal to participate in the study.
The study design was approved by the hospital ethics committee on 7 October 2010. The Figure shows the flow chart for included and excluded patients during both phases of the study.
The analysis performed to identify the prevalence and preoperative predictors of postoperative delirium included all patients in the study who were treated on either of the two surgical wards between March 2011 and June 2012 (n = 178). Mean patient age was 76.8 years, and 53.9% of patients (n = 96) were women. Patients’ preoperative characteristics are summarized in Table 3.
The analysis performed to identify the effect of intervention included all patients in the study who were treated between September 2011 and June 2012. There were 53 patients in the control group (mean patient age 76.6 years, 47.2% [n = 25] were women) and 61 patients in the intervention group (mean patient age 77.8 years, 63.9% [n = 39] were women). The descriptive statistics of both groups are summarized in Table 4.
During the intervention phase, on the intervention ward the preoperative screening was used to derive a delirium risk on the basis of general factors favorable to confusion or delirium: attention deficit, pre-existing cognitive deficits (demonstrated using the MMSE), and the duration and extent of the planned surgery. For example, femoral neck fractures are associated with a very high risk of delirium.
The delirium liaison nurse determined the delirium risk independently of the surgical ward staff. On the basis of the determined risk, an individual intervention plan was set up. The following goals were set:
- Improved sleep
- Cognition support
- Structured daily schedule
- Early mobilization
- Involvement of relatives
- Improved nutrition.
Table 2 shows the frequency with which the various interventions were actually used. For patients with postoperative delirium, an interventional support program adapted from the Hospital Elder Life Program (HELP) (31) (Box) was used.
During the prevalence phase, we investigated how often postoperative delirium occurred in the patient population described above. During the subsequent intervention phase, we analyzed whether postoperative delirium occurred significantly less often on the intervention ward than on the control ward.
The statistical package SPSS 21 was used for statistical analysis.
Prevalence of postoperative delirium
Over the whole of the study period, 20.2% of patients (n = 36; 95% confidence interval [CI]: 14.6 to 26.4) who received no specific intervention (n = 178) developed postoperative delirium.
Predictors of postoperative delirium
Descriptive statistics, test statistics, and effect sizes of the factors under consideration for patients with and those without postoperative delirium are listed in Table 3. Numerous variables show differences even preoperatively between those with and those without postoperative delirium.
In multivariate logistic regression analysis with forward selection, the variables age, MMSE, Barthel Index, and infections remained in the model. Only MMSE, age, and preoperative infections proved to be statistically significant (p<0.05). The individual results for these variables are summarized in Table 5.
Efficacy of intervention
Table 4 contains the descriptive statistics and test statistics of the preoperative characteristics in both groups. The intervention group had a higher proportion of patients with a Barthel Index <85 and higher preoperative NOSGER and MADRS scores. The proportion of patients who were admitted from an institution was higher in the intervention group than in the control group.
Overall, during the intervention phase of the study, 3 patients in the intervention group (4.9%; 95% CI: 0.0 to 11.5) and 11 patients in the control group (20.8%; 95% CI: 11.3–32.1) developed postoperative delirium. The χ2 test showed the difference to be significant (χ2 = 6.60; N = 114; df = 1; p = 0.01). The model—adjusted using the “propensity score”—also showed a significant effect of which group a patient was in (odds ratio [OR] = 0.22; 95% CI: 0.05 to 0.98; p = 0.046). Patients in the intervention group had a lower risk of postoperative delirium than did patients in the control group.
Delirium is a frequent condition in older patients on surgical or medical wards in general hospitals, and is associated with high consumption of health resources. The risk of postoperative delirium is particularly high in elderly patients with pre-existing cognitive deficits. Over the period of the present study, 20.2% of patients who received no intervention developed postoperative delirium. This agrees with figures published elsewhere (4).
Our results indicate that patients who develop postoperative delirium are different preoperatively to those who do not. Our data show that, especially, age, pre-existing infections, and the Mini–Mental State Examination score, which indicates existing cognitive deficits, are risk factors for postoperative delirium. The publications of Fischer and Assem-Hilger (32), Margiotta et al. (33), and Robinson et al. (9) support our findings.
Differences in preoperative functional status were also found between the patient groups, using NOSGER. In addition, it was noted that the risk of delirium was higher when patients had a preoperative Barthel Index <85, or lower level of education, or were admitted from an institution.
We obtained clear indications that consistently applied preoperative screening and simple interventions by a delirium liaison nurse—a nurse with many years’ experience of geriatric psychiatric nursing—can reduce the incidence of postoperative delirium. Andrews et al. (34), Holt et al. (35), and Milisen et al. (36) performed their studies under different conditions—in intensive care units or in older patients with femoral neck fractures—but they also showed that consistent monitoring of delirium risk performed by nurses can reduce this risk.
Whereas 20.8% of patients on the control ward during the intervention phase developed postoperative delirium, delirium was observed in only 4.9% of patients on the intervention ward (OR = 0.22; 95% CI: 0.05 to 0.98; p = 0.046). These results agree with those of Zaubler et al. (19), in whose study a HELP approach (31) was also followed, although this study was carried out in a medical ward. Unlike Zaubler et al. (19), who used only a historical control group for comparison, the present study included both an intervention and a (non-intervention) control ward during the intervention phase of the study, which increases the validity of its results. The present study also included validation, sleep improvement, cognitive activation, early mobilization, improved sensory stimulation, and nutritional and fluid intake during the investigation phase. We take this as a clear indication of the protective effect of such measures in preventing delirium.
This assessment also agrees with the findings of a recent meta-analysis of 14 intervention studies on non-drug prevention of delirium (37), which showed that multimodal non-drug delirium prophylaxis can reduce the incidence of delirium.
Some restrictions need to be observed when interpreting the present results. This was not a randomized, placebo-controlled study (RCT), but a service delivery study carried out in the setting of a general hospital.
All the calculated values show relatively wide confidence intervals, but this is probably because the patient population was quite small and only a moderate number of patients developed delirium.
A limitation of this study is that, because of the low numbers involved (interventions undertaken in 65 of 320 patients) and because of the study design, it was not possible to analyze statistically the extent to which the various individual interventions can prevent postoperative delirium. In addition, it should be noted that the intervention group had a markedly higher percentage of patients with a low Barthel Index or a higher NOSGER score, indicating that the patients in this group already had greater physical and functional impairment. Despite the poorer initial conditions in the intervention group, intervention significantly reduced the incidence of postoperative delirium. During the intervention phase, a geriatric department was established in the hospital which was physically close to the control ward but not to the intervention ward. Despite this, however, the incidence of postoperative delirium was significantly reduced on the intervention ward compared to the control ward.
The present study focused on non-drug interventions for the prevention of postoperative delirium. Whether interventions based on the use of psychoactive drugs—e.g., preoperative administration of antipsychotics—have a preventive effect against postoperative delirium, remains unknown at present (10, 38, 39).
We believe that if the medical staff caring for the patient understand the risk factors, this can have a critical effect in reducing postoperative delirium. Establishing a delirium liaison nurse, who carries out screening for risk factors for postoperative delirium preoperatively and cognitive activation of the patient peri- and postoperatively, could be an important step towards improving treatment outcomes in older patients undergoing surgery in general hospitals.
Nursing staff in particular would be trained by a delirium liaison nurse in screening for risk factors and would learn simple methods and tools for delirium prophylaxis, e.g., cognitive activation or validation. Without this, lack of understanding or ignorance on the part of medical staff could lead to an increased incidence of delirium. This is why it is so important for specific treatment guidelines to be integrated into the hospital clinical routine for nurses and doctors in training. We believe that employing a delirium liaison nurse could be an important contribution toward this.
The delirium liaison nurse could be effective not just through his or her own immediate clinical activity, but as part of a multi-professional team on a surgical ward would have a considerable educational effect on all members of the team (learning by watching) (40).
In our view, further studies with larger patient numbers are needed to establish the part played by the individual interventions in the reduction of postoperative delirium.
Conflict of interest statement
Torsten Kratz has received lecture fees from Janssen-Cilag, Pfizer, and Lilly.
Albert Diefenbacher has received lecture fees from Janssen-Cilag.
Manuel Heinrich and Eckehard Schlauß declare that no conflict of interest exists.
Manuscript received on 13 October 2014, revised version accepted on
9 February 2015.
Translated from the original German by Kersti Wagstaff, MA.
Prof. Torsten Kratz
Evangelisches Krankenhaus Königin Elisabeth Herzberge
Abteilung für Psychiatrie, Psychotherapie und Psychosomatik
Herzbergstr. 79, 10365 Berlin, Germany
A practical method for grading the state of patients for the clinician. J Psychiatr Res 1975; 12: 189–98 CrossRef
|1.||Dilling H, Mombour W, Schmidt MH: Klassifikation psychischer Krankheiten. Klinisch-diagnostische Leitlinien nach Kapitel V (F) der ICD-10. 9th edition. Bern: Huber Verlag 2014 PubMed Central|
|2.||Saß H, Wittchen H, Zaudig M: Diagnostisches und Statistisches Manual psychiatrischer Störungen DSM-IV. 3rd edition. Göttingen: Hogrefe Verlag 2000.|
|3.||Fong TG, Tulebaev SR, Inouye SK: Delirium in elderly adults: diagnosis, prevention and treatment. Nat Rev Neurol 2009; 5: 210–20 CrossRef MEDLINE PubMed Central|
|4.||Bickel H, Gradinger R, Kochs E, Förstl H: High risk of cognitive and functional decline after postoperative delirium: a three year prospective study. Dement Geriatr Cogn Disord 2008; 26: 26–31 CrossRef MEDLINE|
|5.||Elie M, Cole MG, Primeau FJ, et al.: Delirium risk factors in elderly hospitalized patients. J Gen Intern Med 1998; 13: 204–12 CrossRef MEDLINE PubMed Central|
|6.||Inouye SK, Charpentier PA: Precipitating factors for delirium in hospitalized elderly persons: predictive model and interrelationship with baseline vulnerability. J Am Med Assoc 1996; 275: 852–7 CrossRef CrossRef|
|7.||Fick D, Foreman M: Consequences of not recognizing delirium superimposed on dementia in hospitalized elderly individuals. |
J Gerontol Nurs 2000; 26: 30–40 CrossRef MEDLINE
|8.||Isaia G, Astengo MA, Tibaldi V, et al.: Delirium in elderly home-treated patients: a prospective study with 6-month follow-up. Age 2009; 31: 109–17 CrossRef MEDLINEPubMed Central|
|9.||Robinson TN, Raeburn CD,Tran ZV, et al.: Postoperative delirium in the elderly: risk factors and outcomes. Ann Surg 2009; 249: 173–8 CrossRef MEDLINE|
|10.||AGS: Clinical practice guideline for postoperative delirium in older adults. www.archcare.org/static/files/pdf/ags-2014-clinical-practice-guideline-for-postop-delirium-in-older-adults.pdf (last accessed on 7 January 2015).|
|11.||Gemeinnützige Gesellschaft für soziale Projekte mbh: Projekt Blickwechsel – Nebendiagnose Demenz. www.blickwechseldemenz.de/content/e964/e1583/ProjektBlickwechsel_A4.pdf (last accessed on 7 January 2015).|
|12.||Caritasverband für die Diözese Münster e.V.: Demenzleben. Gemeinsam für ein besseres Leben mit Demenz. www.caritas-muenster.de/service/dokumentationprojekte/demenzleben/demenzleben (last accessed on 7 January 2015).|
|13.||Gurlit S, Thiesemann R, Wolff B, Brommer J, Gogol M: Caring for people with dementia in general hospitals: an education curriculum from the Alzheimer’s Society of Lower Saxony. Z Gerontol Geriatr 2013; 46: 222–5 CrossRef MEDLINE|
|14.||Kirchen-Peters S, Diefenbacher A: Gerontopsychiatrische Konsiliar- und Liaisondienste – eine Antwort auf die Herausforderung Demenz? Z Gerontol Geriatr 2014; 47: 595–604 CrossRef MEDLINE|
|15.||Hibbeler B: Stationäre Behandlung: Der alte Patient wird zum Normalfall. Dtsch Arztebl 2013; 110: 1036–7 VOLLTEXT|
|16.||Hibbeler B: Krankenhaus: OP gelungen, Patient Pflegefall. Dtsch Arztebl 2014; 111: 477 VOLLTEXT|
|17.||Kratz T: Delir bei Demenz. Z Gerontol Geriat 2007; 40: 96–103 CrossRef MEDLINE|
|18.||Kratz T, Diefenbacher A: Gerontopsychiatric consultation-liaison psychiatry. Z Psychiatr Psychol Psychother 2008; 56: 39–45 CrossRef|
|19.||Zaubler TS, Murphy K, Rizzuto L, et al.: Quality improvement and cost savings with multicomponent delirium interventions: replication of the hospital elder life program in a community hospital. Psychosomatics 2013; 54: 219–26 CrossRef MEDLINE|
|20.||Hewer W, Rössler W: Akute psychische Erkrankungen – Management und Therapie. 2. Auflage. München: Urban & Fischer Verlag/Elsevier GmbH 2007.|
|21.||Lorenzl S, Füsgen I, Noachtar S: Acute confusional states in the elderly— diagnosis and treatment. Dtsch Arztebl Int 2012; 109: 391–400 VOLLTEXT|
|22.||Folstein MF, Folstein SE, McHugh PR: „Mini-Mental State“. |
A practical method for grading the state of patients for the clinician. J Psychiatr Res 1975; 12: 189–98 CrossRef
|23.||Katz S, Ford AB, Moskowitz RW, Jackson BA, Jaffe AW: Studies of illness in the aged. The index of ADL: a standardized measure of biological and psychosocial function. JAMA 1963; 185: 914–9 CrossRef MEDLINE|
|24.||Hestermann U, Backenstrass M, Gekle I, et al.: Validation of a German version of the confusion assessment method for delirium detection in a sample of acute geriatric patients with a high prevalence of dementia. Psychopathology 2009; 42: 270–6 CrossRef MEDLINE|
|25.||Trzepacz PT, Dinesh Mittal, Torres R, Kanary K, Norton J, Jimmerson N: Validation of the delirium rating scale-revised-98: comparison with the delirium rating scale and the cognitive test for delirium. J Neuropsychiatry Clin Neurosci 2001; 13: 229–42 CrossRef|
|26.||Spiegel R, Brunner C, Ermini-Fünfschilling D, et al.: A new behavioral assessment scale for geriatric out- and in-patients: the NOSGER (Nurses’ Observation Scale for Geriatric Patients). J Am Geriatr Soc 1991; 39: 339–47 MEDLINE|
|27.||Mahoney FI, Barthel DW: Functional evaluation: the Barthel-Index. Md State Med J 1965; 14: 61–5 MEDLINE|
|28.||Montgomery SA, Asberg M: A new depression scale designed to be sensitive to change. Br J Psychiatry 1979; 134: 382–9 CrossRef|
|29.||Feil N: Validation therapy. Geriatr Nurs 1992; 13: 129–33 CrossRef|
|30.||Feil N, Altman R: Validation theory and the myth of the therapeutic lie. Am J Alzheimers Dis Other Demen 2004; 19: 77–8 CrossRef MEDLINE|
|31.||Strijbos MJ, Steunenberg B, van der Mast RC, Inouye SK, Schurmans MJ: Design and methods of the Hospital Elder Life Program (HELP), a multicomponent targeted intervention to prevent delirium in hospitalized older patients: efficacy and cost-effectiveness in Dutch health care. BMC Geriatr 2013; 13: 78 CrossRef MEDLINE PubMed Central|
|32.||Fischer P, Assem-Hilger E: Delir/Verwirrtheitszustand. In: Förstl H (eds): Lehrbuch der Gerontopsychiatrie und -psychotherapie. Grundlagen-Klinik-Therapie. Stuttgart: Thieme 2003: 394–440.|
|33.||Margiotta A, Bianchetti, Ranieri P, Trabucchi M: Clinical characteristics and risk factors of delirium in demented and not demented elderly medical inpatients. J Nutr Health Aging 2006; 10: 535–9 MEDLINE|
|34.||Andrews L, Silva SG, Kaplan S, Zimbro K: Delirium monitoring and patient outcomes in a general intensive care unit. Am J Crit Care 2015; 24: 48–56 CrossRef MEDLINE|
|35.||Holt R, Young J, Heseltine D: Effectiveness of a multi-component intervention to reduce delirium incidence in elderly care wards. Age Ageing 2013; 42: 721–7 CrossRef MEDLINE|
|36.||Milisen K, Foreman MD, Abraham IL, et al.: A nurse-led interdisciplinary intervention program for delirium in elderly hip-fracture patients. J Am Geriatr Soc 2001; 49: 523–32 CrossRef MEDLINE|
|37.||Hshieh TT, Yue J, Oh E, et al.: Effectiveness of multicomponent nonpharmacological delirium interventions: a meta-analysis. JAMA Intern Med 2015; 175: 512–20 CrossRef MEDLINE|
|38.||Teslyar P, Stock VM, Wilk CM, Camsari U, Ehrenreich MJ, Himelhoch S: Prophylaxis with antipsychotic medication reduces the risk of post-operative delirium in elderly patients: a meta-analysis. Psychosomatics 2013; 54: 124–31 CrossRef MEDLINE|
|39.||Gilmore ML, Wolfe DL: Antipsychotic prophylaxis in surgical patients modestly decreases delirium incidence—but not duration—in high-incidence samples: ameta-analysis. Gen Hosp Psychiatry 2013; 35: 370–5 CrossRef MEDLINE|
|40.||National Institute for Health and Care Excellence: Delirium. Diagnosis, prevention and management. NICE clinical guideline 103. www.nice.org.uk/guidance/cg103/resources/guidance-delirium-pdf (last accessed on 6 January 2015).|