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Implementation of Strategies to Prevent and TreatPostoperative Delirium in the Post AnesthesiaCaring Unit. A German Survey of Current PracticeThomas Saller 

Department of Anaesthesiology, University Hospital, LMU Munich https://orcid.org/0000-0003-3987-6272Klaus F. Hofmann-Kiefer 

Department of Anaesthesiology, University Hospital, LMU MunichIsabel Saller 

Department of Intercultural Communications, LMU MunichSimon T. Schaefer 

Department of Anaesthesiology, University Hospital, LMU MunichBernhard Zwissler 

Department of Anaesthesiology, University Hospital, LMU MunichVera von Dossow  ( vvondossow@hdz-nrw.de )

https://orcid.org/0000-0001-7281-2137

Research article

Keywords: Recovery Room, Postanesthesia Nursing, Postoperative Complications, Delirium, PreanestheticMedication, Health Care Survey

Posted Date: August 21st, 2019

DOI: https://doi.org/10.21203/rs.2.13335/v1

License: This work is licensed under a Creative Commons Attribution 4.0 International License.  Read Full License

Version of Record: A version of this preprint was published on May 9th, 2020. See the published versionat https://doi.org/10.1007/s10877-020-00516-9.

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AbstractBackground

Postoperative delirium is associated with worse outcome. The aim of this study is to understand presentstrategies for delirium screening and therapy in German Post Anesthesia Caring Units (PACU) in hospitalsand ambulatory anesthesia facilities.

Methods

We designed German-wide web-based survey of 922 leading anesthesiologists in hospitals and 726 inambulatory surgery.

Results

The response rate was 30% for hospital anesthesiologists. 10% (95%-con�dence interval: 8–12) of theanesthesiologists applied a standardised screening for delirium. Even though not on a regular basis, in44% (41–47) of the hospitals, a recommended and validated screening was used, the Nursing DeliriumScreening Scale (NuDesc) or the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Ifdelirium is likely to occur, 46% (43–50) of the patients were examined using a delirium tool and 20% (17–23) screened in intensive care units. For the treatment of delirium, alpha-2-agonists (83%, 80–85) wereused most frequently for vegetative symptoms, benzodiazepines in anxiety in 71% (68–74), typicalneuroleptics in 77% (71–82%) of patients with psychotic symptoms and in 20% (15–25) of patients withhypoactive delirium. 45% (39–51) of the respondents suggested no therapy for this entity. One third ofthe respondents indicated an age limit for pre-anesthetic medication with a mean age (SD) of 74.2 (±6.4)years and avoid benzodiazepines.

Conclusions

Monitoring of delirium was not established as a standard procedure in German PACUs. However,symptom-oriented therapy for postoperative delirium corresponded with the current guidelines.

BackgroundThe recovery unit, also known as post anesthesia caring unit (PACU), provides ongoing nursing andmedical care by specially trained personnel until the patient has completely emerged from anesthesia. Inorder to diagnose and treat potential adverse events, German guidelines postulate the permanentpresence of an anesthesiologist. By all means, a trained anesthesiologist must be on short call (1).

Delirium

Postoperative Delirium (POD) may occur, especial in the elderly, in up to 50 % of the patients and isaccountable for increased mortality (2). A recent study showed that up to 19 % of the post-surgical

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patients developed delirium at the ward (3) and that 14 % of the patients were already tested positive fordelirium in the PACU (4). Already 10 minutes after PACU admission, a pathologic RASS or NuDeSc-Score,often described as emergence delirium (ED), was associated with delirium (OR 2.4, 1.5–3.9 CI) and deathafter three months (OR 1.4; 0.7–3.4 CI) (5). Immediately after awakening and extubation, Monk found a3.7% incidence of ED, declining to 1.3% when re-evaluated in the PACU (6). Another study found a 4%incidence of ED at the time of discharge (7). In contrast to ED, (post-operative) hypoactive delirium hassubtle symptoms and is even more frequent. Therefore, a standardised delirium screening has beenproposed by Radtke et al. (4) and the recently published European Guideline (8) also underlines screeningfor POD in all surgical patients. Screening should already start in the PACU and should be carried out ineach shift up to postoperative day 5 with a validated delirium score (8). Besides the scienti�c studies thatled to the development of the current guideline, there is no research or data outlining current strategies fordelirium management in the PACU. However, a detailed insight into the characteristics of clinical practicewould be extremely fruitful for a successful implementation of the guidelines (9).

Pharmacological Premedication and Delirium Management

Pharmacological premedication before anesthesia and surgery reduces anxiety and improves inductionconditions as well as postoperative pain management (10). Typically, benzodiazepines are administered(11). Concerning the risk-bene�t assessment, the necessity of premedication for all patients has beenquestioned (12, 13). Pharmacological premedication with benzodiazepines is associated with anincreased risk of postoperative delirium (14–16), especially in the elderly. Concerns involve the possibleanticholinergic burden of premedication medication. Especially in combination with polypharmacy in theelderly, a routine premedication for these patients is open to question (17, 18).

To document organizational strategies and the current practice on strategies for delirium prophylaxis, useof delirium tools for screening and therapy in German PACUs together and oral premedication with itsassociations subject to the clinical sector and the size of the institution, we designed a prospective,German-wide online survey.

MethodsThis manuscript documents German standards in postoperative care via an online survey (19), meetingthe COREQ criteria for the reporting of qualitative studies (20). After reconciliation and approval by theethics committee, Faculty of Medicine, LMU Munich, a mailing list provided by the German Society ofAnaesthesiology and Intensive Care Medicine (DGAI) and the German Anaesthesiologists Association(BDA) was used to invite 922 leading anesthesiologists in an executive position for at least one of the1,173 departments of anesthesiology in German hospitals and 726 anesthesiologists working in anambulatory setting to take part in the electronic survey (LimeSurvey 2.05 software package (LimeSurveyGmbH, Hamburg, Germany). To remove responder bias, the questionnaire was re-sent once. In a shortintroduction we explained the signi�cance of delirium monitoring in critical and postoperative care andthe objective of the study. Informed consent was obtained before the 25 questions could be answered

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anonymously. The questionnaire was published before (9) and covered structural data and informationabout delirium screening and therapy. All participation data, necessary for an email reminder, were erasedafter the completion of the survey.

Statistical Analysis

In order to estimate the relevant percent or proportion, results are being presented as correlation of theanswers to the total cohort together with a 95%-con�dence interval, calculated by the Clopper-Pearsonmethod. For comparing means, the Mann-Whitney-U-Test was used. Categorical data were analysed bythe Χ2-test or Fisher’s exact test, determining the level of signi�cance as α = 5 %. A correlation wasdetermined by Spearman’s non-parametric correlation coe�cient rho. To compare correlations, Fisher’s zwas used. To show reach and frequencies of different recommendations for delirium screening, a TotalUnduplicated Reach and Frequency (TURF) analysis (21, 22) was executed. For statistical analysis weused SPSS Statistics 25 (IBM Corp., USA).

ResultsStructural Data

The survey was open for participation between 4th of May and 21st of June 2015. Participation was30 % among hospital anesthesiologists (n = 275/922) and 6 % among ambulant surgeryanesthesiologists (n = 44/726). 5 participants declined to participate or opted out. 292 completed thequestionnaire within a median of 7.9 minutes. Questions only referring to PACU care were answered by276 anesthesiologists. Of these responders, 70 % (95 %-con�dence interval 65–76 %) were head of theirdepartment, 18 % (14–23 %) senior consultants and 12 % (8–16 %) other physicians. 237 (86 %; 81–90%) of the anesthesiologists worked at a hospital, 39 (14 %; 10–19 %) in an outpatient setting. 19 (7 %; 4–10 %) worked at a university hospital, 39 (13 %; 10–18 %) were associated with a university at a teachinghospital. The reported number of hospital beds correlated with the number of PACU beds with anestimated Spearman’s correlation of r = 0.674 (p<0.001) and well correlated with the number ofanesthetic procedures (r = 0.593; p<0.001). The number of anesthetic procedures correlated with thenumber of PACU beds (r = 0.512; p<0.001). No statistical difference was found between correlations inambulatory and hospital anesthesia for these association (z = 0.5545; p = 0.579).

Organizational Strategies Regarding Delirium in the PACU

In 19 % (14–24 %) of the hospitals, permanent medical care was exclusively provided for the PACU. Thecontinuous presence of an anesthesiologists was reported in >75 % only in hospitals with more than 30PACU beds and more than 45,000 procedures per annum.

In 10 % (6–14 %) of the participating hospitals and 13 % (4–27 %) in ambulant anesthesia, (p = 0.560) astructured delirium screening was being provided postoperatively in the PACU.

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To detect a delirious state 44 % of the anesthesiologists, who routinely score for delirium, used one of thetwo recommended tools at the PACU for in- as well as outpatient care: the Confusion Assessment Methodfor the Intensive Care Unit (CAM-ICU; 11 % (8–16 %)) and the Nursing Delirium Screening Scale (NuDESC12% (8–17 %). 5 % even had two tools in use (see table 3). 65 % (59–70 %) of the respondents did notuse any score at all. Patients diagnosed positively for delirium were mostly transferred to an intensivecare unit (72 % (66–77 %); statistical difference between the hospital (78 %; 72–83 %) and ambulantsetting (36 %; 21–53); p<0.001), 16 % (12–20 %) were being transferred to a regular ward. 38 % of theanesthesiologists in hospitals informed ward nurses about the delirium, 46 % noti�ed the physician incharge. 14 % (10–19 %) organised an individual bedside observation or night watch for the deliriouspatient (12 % (8–17 %) in hospital versus 28 % (15–45 %) in ambulant care, p = 0.012) and 12 % (8–17%) consulted a psychiatrist.

Pharmacological Treatment of Postoperative Delirium in the PACU

Neuroleptics were the drugs most frequently used in at least every �fth case of PACU delirium and in upto 77 % (71–82 %) for patients with delusions (see table 5), whereas atypical neuroleptics were rarelyused in the PACU.

For anxiety benzodiazepines were used in every second case. Ambulant anesthesiologists used shorteracting medication for the therapy of delirium than hospital anesthesiologists, especially propofol for allsymptoms of delirium. For vegetative symptoms caused by delirium, alpha–2-agonists wereadministered in 83 % (76–87 %) of all cases.

Physostigmine, the antidote for anticholinergic acting drugs, was not included in the questionnaire butwas provided as a free-text answer for the therapy of PACU delirium, especially in the hypoactive form, by12 % (8–16 %) of the respondents. Almost every second anesthesiologist did not treat hypoactivedelirium.

Preoperative Strategies Regarding Delirium

43.1 % (37.2–49.2%) of all anesthesiologists (42.2 % hospital/48.7 % ambulant anesthesiologists; p =0.277) in our survey informed patients about delirium during preoperative evaluation.

For preanesthetic drug therapy (premedication) prior to the induction of anesthesia, one third of theanesthesiologists (33 % (27–39 %) in hospitals/16 % (6–31 %) ambulatory) approved of a cut-off at aspeci�c age, with a mean at the age (SD) of 74.3 (±6.4) years (�gure 1). That implies that two third of theanesthesiologists used drugs for premedication also in geriatric patients. Those who considered a cut-offto be reasonable used benzodiazepines rarely and preferably prescribe neuroleptics, opioids and alpha-agonists instead. Particularly promethazine was frequently used in the elderly, even though it has anextraordinary high anticholinergic burden (17, 18), see table 6. The long-acting clorazepate was lessfrequently used in out-patient than in-patient anesthesia.

Policies for Delirium Screening in German Hospitals with a Department of Anesthesia

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Asked for the preferences of all participating anesthesiologists on delirium screening in their dailypractice, 77 % (71–82 %) carried out a delirium screening for at least one of the suggested groups ofpatients (see table 4). In contrast, one fourth would not screen for delirium under any circumstances.Delirium screening was applied in only 46 % (40–52 %) of the patients even when delirium is suspected.

DiscussionThe objective of our research was to elucidate current strategies in the handling of delirium. With 30 % forhospital anesthesiologists s, its participation rate lies within a typical range for online surveys (19) and�ts response rates of the same cohort (23).

This survey shows that delirium screening rate were low in German PACUs despite the fact that today theGerman and European guidelines plead for postoperative delirium screening as a standard operatingprocedure for evidence-based practice and that several scienti�c studies showed a high delirium rate inthe PACU (8). The results of these studies have not yet led to a cultural change in delirium management.

Only 9 % of the participating hospitals screen for delirium in the PACU. 10 % of the respondents hadimplemented structured programs at their facilities. 46 % used a tool to screen patients even if deliriumwas suspected and two thirds of the anesthesiologists did not use a delirium score in the PACU at all. Incontrast, in an ICU-setting 72 % of the anesthesiologists already used a scoring system (9), which leads tothe conclusion that delirium screening in the ICU is much better established as it is in PACUs. It isreasonable to expect, that with further promotion of the recently published European Guidelines anincrease in screening rates will take place in the PACU as well.

The awareness of these low screening rates—elaborated in the present research—could be a �rst steptowards improving the patients’ outcome caused by delirium.

The second step would be to ensure the implementation of the guidelines. Therefore, information for allmedical employees on delirium, e.g. with bedside teaching to the caregivers, would be necessary. It hasbeen documented that multicomponent programs for delirium prevention can reduce the incidence ofdelirium (24) and, in a geriatric population, the length of stay and hospital costs (25).

The introduction of an anesthetic protocol, designed to diminish adverse anesthetic effects, includingdelirium, is associated with a reduction of anesthetic recovery time (26) and thus reducing costs (about10.80 € per minute for PACUs in a French study (27)). As a consequence, implementation of a structuredprotocol (28) for early delirium screening is cost-effective as it reduces PACU time and occupies fewerPACU nurses. A promising approach might be a standing order procedure, worked out by amultidisciplinary team of nurses, physicians and other experts, as the guidelines (8) suggest.

The third step would involve further raising awareness for the necessity of care for delirium amongphysicians as well as nurses and other caregivers. Our survey showed that in four out of �ve PACUs thereis neither a physician permanently present nor did a structured delirium screening take place (in 1 of 10

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PACUs). Anesthesiologists on duty at the PACU—continuously as in university PACUs or on short call atothers—could foster these considerations by acting as role models. Therefore, interdisciplinarycommunication between all personnel involved in delirium care would need to be improved as it has beenidenti�ed as a major issue impeding successful guideline implementation (29).

Delirium on the Ward

Only every tenth hospital provided a structured screening for delirium at the time of the survey, 1 % of therespondents practiced delirium screening in regular wards, 6 % in gerontology wards and 10 % in regularwards postoperatively.

Even when supposing that all patients at a hospital are screened, a maximum of 75 % of the patientswould be tested for delirium according to a TURF analysis (21). In contrast, 25 % of the respondentswould not be reached by any recommendation. Including these caregivers could be one of the biggestchallenges when putting the recently published European Guidelines (8) into practice. The awarenessand, if necessary, a rethinking of delirium as a sign and symptom of major complications, a strongpredictor of death after arti�cial (30) as well as non-invasive ventilation (31), and a cause of exceedinglyhigher costs for the healthcare system (32) might help to launch substantiated, elaborated clinicalprograms for delirium management. More robust results from well-powered, randomised clinical trialsshould underline these �ndings.

Therapy of Delirium

Our study also showed that the therapy of delirium, once diagnosed, is very heterogeneous. Most of theanesthesiologists con�rm a pathophysiological approach to the therapy of delirium, yet there are nostrong, evidence-based recommendations for therapy of PACU delirium besides the European Society ofAnaesthesiology (ESA) recommendation to titrate haloperidol 0.25 mg-wise (level of recommendation ‘B’),administered by the respondents in our study to 20–80 % of delirious patients, according to their deliriumsubtype. Only half of the respondents treated hypoactive delirium, the subtype most frequent and at thesame time hardest to identify. Consequently, one has to assume that most of the delirious patients(especially with hypoactive delirium) were not correctly diagnosed and accordingly obtained nocorrespondent therapy. That �nding implies on what future research might put a focus.

Rethinking Routine Premedication

Not only organizational issues are essential for delirium management. According to the ESA guidelines(8), a routine premedication should be avoided in a patient older than 65 years, except for severelyanxious patients (level of recommendation ‘B’). Only one third of the anesthesiologists proposed a cut-offat age for premedication, which though lies nine years above the ESA recommendation. Studies tocon�rm or refute the superiority of pharmaceutical benzodiazepine premedication especially in the elderlyare underway (33). For a rigorous implementation of the guidelines many hospitals would have toreshape their standard operating procedures on premedication.

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LimitationsA qualitative online survey is a viable method for the identi�cation of barriers to adherence to andimplementation of guidelines (34). In every qualitative study, however, a bias of social desirability mustbe assumed, thus possibly leading to more positive �ndings than a neutral observation of organizationalpractice could reveal. Since participation in an online survey can be carried out anonymously, falseanswers are negligible.

Neither surgeons nor nurses participated in the survey, thus, the results of this survey cannot betransferred to specialties other than anesthesiology. However, our work may overestimate the level ofimplementation by focusing on the expertise of leading physicians.

Our respondents represent a �fth of all leading German anesthesiologists. However, only a fewcolleagues working in an outpatient setting participated in the study. One needs to judge these resultsvery carefully when drawing any conclusions concerning this group.

Our data re�ect the German perspective of delirium management before the implementation of the ESAguideline in 2017. Further studies should now examine how the publication of the guideline has changeddelirium management. Lastly, one would need to discuss, while taking into consideration the differencesin health systems and intercultural issues, how these results might be transferable to other nationalcontexts.

ConclusionThe aim of this study was to understand organizational practice concerning PACU medical personnel, pre-anesthetic medication, and strategies for delirium screening and therapy in German PACUs in hospitalsand ambulatory anesthesia facilities. Only 10 % of the participating hospitals in our survey provided astructured delirium screening for their postoperative patients in the PACU. Where already implemented,validated scores were used. The hypoactive form of delirium was rarely treated with any medication. Thecurrent cut-off age for premedication in the elderly lies nine years above evidence-basedrecommendations.

Our results show furthermore that standards for delirium prophylaxis and screening in the PACU were lowbefore the publication of the ESA guidelines (8). According to these evidence-based and consensus-basedguidelines on postoperative delirium, patients should not leave the PACU without having been screenedfor POD and screening is recommended up to the �fth postoperative day (8).

Future studies should examine implementation rates at short intervals in order to reveal obstacles inapplying these guidelines.

Abbreviations

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PACU Post Anesthesia Caring Unit POD Postoperative Delirium ED emergence delirium RASS RichmondAgitation Sedation Scale NuDESC Nursing Delirium Screening Scale OR odds ratio CI Con�dence intervalCAM-ICUConfusion Assessment Method for the Intensive Care Unit TURF Total Unduplicated Reach andFrequency Analysis ESA European Society of Anaesthesiology

DeclarationsEthics approval and consent to participate

The study was approved by the ethics committee, Faculty of Medicine, LMU Munich, on March 24th 2015(reference number 180–15). Written informed consent was waived by the ethics committee. However,every participant clearly stated her or his will to participate by activating a checkbox in the online tool.

Consent for publication

Not applicable.

Availability of data and material

The datasets used during the current study are available from the corresponding author on reasonablerequest.

Competing interests

BZ is the former elected president of the German Society of Anaesthesiology and Intensive CareMedicine (DGAI); STS is Associate Editor for BMC Anesthesiology. KHK, IS, VvD, TS: None.

Funding

We acknowledge support by the DFG Open Access Publication Funds of the Ruhr University of Bochum,which had neither any role in the design of the study, the collection, analysis and interpretation of datanor in writing the manuscript.

Authors’ contributions

TS and IS designed the questionnaire, TS performed the survey, analysed the data and wrote the draft ofthe manuscript. KHK, IS, STS, BZ and VvD approved the questionnaire, discussed the data, proofread andrewrote the manuscript. All authors have read and approved the manuscript.

Acknowledgements

Data regarding pharmaceutical premedication before anesthesia were presented during a poster sessionat the “Hauptstadtkongress der DGAI”, the annual meeting of the German anaesthesiologists’ society, inBerlin in September 2016.

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We would like to thank the o�ce of the German Society of Anaesthesiology and Intensive CareMedicine (DGAI), Mr. Holger Sorgatz and Mrs. Monique Minde (Nuremberg, Germany) for their kindsupport in the preparation and execution of the survey, and Prof. Gernot Marx (Department of IntensiveCare and Intermediate Care, RWTH University Hospital Aachen, Aachen, Germany) on behalf of the DGAIintensive care working committee for his permission to conduct the study and his kind support.

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Tables

Table 1. Number of Anesthetic Procedures per Year Among the Participants

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Anesthetic Procedures per Year Frequency Percentage

0-2,500 43 14.7

2,501-5,000 67 22.9

5,001-15,000 143 49.0

15,001-30,000 30 10.3

30,001-45,000 5 1.7

> 45,000 4 1.4

total 292 100,0

 

 

Table 2. Presence of an Anesthesiologist in the PACU Related to PACU Capacity

Number of PACU BedsPhysician Presence in the PACU (n = 49)

1-4 26.5%

5-9 13.8%

10-19 16.5%

20-29 33.3%

>30 75.0%a

a Significant difference between groups, p<0,009

 

 

Table 3. Instruments used for Delirium Detection in the PACU

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Screening Instrument Totals Ratio

CAM (Confusion Assessment Method) 10 3.6 %

CAM-ICU (CAM for the Intensive Care Unit) 27/0 a 11.4/0%

DDS (Delirium Detection Scale) 7 2.5%

DRS-R98 (Delirium Ratings Scale Revised 98) 0 -

ICDSC (Intensive Care Delirium Screening Checklist) 5 1.8%

NuDesc (Nursing Delirium Screening Scale) 28/0 a 11.8/0%

DSM (Diagnostic and Statistical Manual of Mental Disorders) or

ICD-10

16/8 b 6.8/20.5%

PAED (Pediatric Anesthesia Emergence Delirium Scale) 2/8 c 0.8/20.5%

a If a significant difference between hospital and ambulant anesthesiologists arose, data are

shown for hospital and ambulatory anesthesiologists); p=0.019

b p≤0.01

c p=0,000003

 

 

Table 4: Circumstances of Delirium Screening

Page 15/21

When Delirium Screening is Performed: Totals

(n=292)

Ratio

 

when delirium is suspected 133 45.5

as circumstances demand 114 39.0

only in critically ill patients 57 19.5b,c

only when neurological abnormalities occur 36 12.3

only postoperatively 27 9.2

special care (e.g. stroke unit, chest pain unit) 23 7.9

gerontologic wards 18 6.2

all patients 8 3.1

only in the elderly 8 2.7

on PACU discharge 7 2.4

also in pediatric patients 5 1.7 c

on PACU admission and discharge 5 1.7

normal care (ward) 3 1.0

emergency room 1 0.3

a Response to the question “In what framework do you usually administer a delirium

score?”, multiple answers suitable.

b Significant difference to all groups (p=0.001).

c Significant difference between hospital and ambulant anesthesia (p<0.05).

Table 5. Medication Used for the Therapy of Delirium

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Medication Used Vegetative

Symptoms

Anxiety Psychotic

Symptoms,

Hyperactivity

Hypoactive

Delirium

Typical Neuroleptics 40.2

(43.9/17.9)c

20.7

(19.9/0.7)c

76.8

(82.3/43.6)d

19.9

Atypical Neuroleptics 4.3 3.6 15.6 13.8

(15.6/2.6)b

Long-acting

Benzodiazepines

9.4 48.2

(52.3/23.1)d

9.4 2.9

Short-acting

Benzodiazepines

22.8

(20.7/35.9)b

40.6

(36.7/64.1)c

19.2

(16.5/35.9)c

6.5

Alpha-2 agonists 82.6

(84.8/69.2)b

29.0 38.0 10.9

Beta-blocker 11.2 0.4 1.4 0

Propofol 14.5

(11.0/35.9)d

10.5

(8.4/23.1)b

11.6

(8.4/30.8)d

1.1

Physostigmine 5.8 0.4 4.0 12.0

No Medication 2.2 8.2 3.6 45.2

a Answers to the question "What medication do you use for the therapy of delirium in the

PACU by symptoms?”. Total ratio (%) of answers (multiple answers suitable) in all

respondents. If a significant difference between groups existed, data are shown separately

(hospital/ambulatory).

b significant difference between ambulant and hospital anesthesia (p<0.05)

c significant difference between ambulant and hospital anesthesia (p<0.01)

d significant difference between ambulant and hospital anesthesia (p<0.001)

 

Page 17/21

 

 

Table 6: Medication Used for Premedication Prior to Anesthesia

Page 18/21

Medication All

Participants

(n=290)

Age

above

Cut-off a

(n=93)

Anticholinergic

Activity bATC code

Long-acting

benzodiazepines

23 (8.3%) 1 (1.1%) low N05BA01, N05CD06

Short-acting

benzodiazepines

208 (75.4%) 13 (14%) low N05BA06, N05CD08

Clorazepate c 78 (28.3%) 4 (4.3%) high/low N05BA05

Neuroleptics

(Haloperidol)

7 (2.5%) 2 (2.2%) low N05AD01

Promethazine 7 (2.5%) 11

(11.8%)

high R06AD02

Anticholinergics, e.g.

atropine

3 (1.1%) 0 high A03BA01

Opioids, e.g.

Meperidine

 - like Pethidine

(Dolantin®)

10 (3.4%) 4 (4.3%) low N02AB02

          Oxycodone – 4 (4.3%) low N02AA05

Alpha-2 agonists 34 (12.3%) 11

(11.8%)

- C02AC01, N05CM18

Ketamine 3 (1%) 3 (3.2%) - N01AX04

a Participants arguing for an age limit for the use of the given medication

Page 19/21

b Anticholinergic risk according to Duran, Azermai (18)

c Significant difference between hospital and ambulant anesthesia: 73 (30.8%) vs. 5(12.8%), p=0.021

Figures

Figure 1

Cut-off for a Standardised, Medical Premedication before General Anesthesia. The �gure shows at whichage anesthesiologists suspend medicaments for premedication prior to anesthesia.

Page 20/21

Figure 2

TURF-Analysis. In a weighted TURF-analysis on delirium screening for the relevant groupsrecommendations for delirium screening would �t German anesthesiologists’ expectations in a maximumof 221 participants (75.7%), when screening is recommended in one or more of the following settings:delirious or noticeable neurological patients, the elderly or gerontology, for in-hospital patients, particularor critical care, only postoperatively and reaches > 95% of the patients and >90% excluding “elderly” and

Page 21/21

“all patients” in a hospital cohort (220 participants, 75.3%). TURF analyses are typically used for marketresearch. They are useful to identify the optimal design in a combination of products to achieve amaximum of distribution (range) and sales (frequencies). Adopted on screening methods in medicine, aTURF analysis enables the examination of the total acceptance for a multi-component measure by acombination of separate subgroups. The conjunction of the subgroups in the latter example shows,together with the graph, that even with a clear indication to establish screening for delirium even for allsubgroups as described in table 4, 25% of the participants have not been reached by anyrecommendation – in other words, would not screen any patient. Even in the traditional �elds of criticalcare or when delirium is suspected, 65.1% (reach) would administer a score.

Supplementary Files

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COREQ.pdf