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Adverse postoperative cognitive disorders: a national survey of portuguese anesthesiologists

Abstract

Background and objectives

Postoperative delirium and postoperative cognitive dysfunction are some of the most common complications in older surgical patients and are associated with adverse outcomes. The aim of this study was to evaluate portuguese anesthesiologists’ perspectives and knowledge about adverse postoperative cognitive disorders, and routine clinical practice when caring for older surgical patients.

Methods

We used a prospective online survey with questions using a Likert scale from 1 to 5 (completely disagree to completely agree), or yes/no/don’t know answer types. Potential participants were portuguese anesthesiologists working in hospitals affiliated with the portuguese national health system and private hospitals.

Results

We analyzed 234 surveys (17.7% of total potential respondents). The majority believed that the risk of cognitive side effects should be considered when choosing the type of anesthesia (87.6%) and that preoperative cognitive function should be routinely assessed (78.6%). When caring for an agitated and confused patient postoperatively, 62.4% would first administer an analgesic and 11.1% an anxiolytic. Protocols to screen and manage postoperative cognitive disorders are rarely used. Nearly all respondents believe that postoperative delirium and postoperative cognitive dysfunction are neglected areas in anesthesiology.

Conclusions

Overall, participants perceive postoperative cognitive disorders as important adverse outcomes following surgery and anesthesia are aware of the main risk factors for their development but may lack information on prevention and management of postoperative delirium. The majority of hospitals do not have protocols regarding preoperative cognitive assessment, diagnosis, management or follow-up of patients with delirium and postoperative cognitive dysfunction.

KEYWORDS
Postoperative period; Neurocognitive disorders; Delirium; Cognitive dysfunction; Surveys and questionnaires

Resumo

Justificativa e objetivos

O delírio pós-operatório e a disfunção cognitiva pós-operatória são algumas das complicações mais comuns em pacientes cirúrgicos mais idosos e estão associados a desfechos adversos. O objetivo deste estudo foi avaliar as perspectivas e conhecimentos de anestesiologistas portugueses sobre distúrbios cognitivos pós-operatórios e a prática clínica de rotina ao cuidar de pacientes cirúrgicos idosos.

Métodos

Pesquisa prospectiva on-line com perguntas usando uma escala Likert de 1–5 (discordo completamente–concordo completamente), ou respostas como sim/não/não sei. Os potenciais participantes eram anestesiologistas portugueses que trabalhavam em hospitais afiliados ao sistema nacional de saúde português e hospitais privados.

Resultados

Analisamos 234 resultados (17,7% do total dos potenciais respondentes). A maioria acreditava que o risco de efeitos colaterais cognitivos deveria ser considerado ao escolher o tipo de anestesia (87,6%) e que a função cognitiva pré-operatória deveria ser rotineiramente avaliada (78,6%). Ao cuidar de um paciente agitado e confuso no pós-operatório, 62,4% administraram primeiro um analgésico e 11,1% um ansiolítico. Protocolos para detectar e tratar distúrbios cognitivos pós-operatórios são raramente usados. Quase todos os entrevistados acreditam que o delírio pós-operatório e a disfunção cognitiva pós-operatória são áreas negligenciadas na anestesiologia.

Conclusões

Em geral, os participantes percebem os distúrbios cognitivos pós-operatórios como importantes resultados adversos após a cirurgia e anestesia, estão cientes dos principais fatores de risco para seu desenvolvimento, mas podem não ter informações sobre como prevenir e tratar o delírio pós-operatório. A maioria dos hospitais não possui protocolos de avaliação cognitiva pré-operatória, diagnóstico, tratamento ou acompanhamento de pacientes com delírio e disfunção cognitiva no pós-operatório.

PALAVRAS-CHAVE
Período pós-operatório; Distúrbios neurocognitivos; Disfunção cognitiva; Pesquisas e questionários

Introduction

Worldwide the population is aging and the number of older adults undergoing surgery and anesthesia is steadily increasing.11 Etzioni DA, Liu JH, Maggard MA, et al. The aging population and its impact on the surgery workforce. Ann Surg. 2003;238:170-7. Comorbidities and poor baseline functional status put older patients at increased risk for adverse postoperative complications and mortality.22 Hamel MB, Henderson WG, Khuri SF, et al. Surgical outcomes for patients aged 80 and older: morbidity and mortality from major noncardiac surgery. J Am Geriatr Soc. 2005;53:424-9. Postoperative cognitive disorders such as postoperative delirium and postoperative cognitive dysfunction are some of the most common complications in older surgical patients.33 Monk TG, Weldon BC, Garvan CW, et al. Predictors of cognitive dysfunction after major noncardiac surgery. Anesthesiology. 2008;108:18-30.,44 Marcantonio ER. Postoperative delirium: a 76-year-old woman with delirium following surgery. JAMA. 2012;308:73-81.

Postoperative delirium is delirium that occurs in the postoperative period with older patients being at the highest risk.44 Marcantonio ER. Postoperative delirium: a 76-year-old woman with delirium following surgery. JAMA. 2012;308:73-81. The incidence of postoperative delirium can be as high as 53.3%.55 Bruce AJ, Ritchie CW, Blizard R, et al. The incidence of delirium associated with orthopedic surgery: a meta-analytic review. Int Psychogeriatr. 2007;19:197-214. The hallmark of delirium is inattention yet it is only recognized in a fraction of patients without formal testing.66 Whitlock EL, Vannucci A, Avidan MS. Postoperative delirium. Minerva Anestesiol. 2011;77:448-56. In contrast to delirium, postoperative cognitive dysfunction is a research classification that requires both pre- and postoperative cognitive assessment with an incidence of 20–26%.77 Moller JT, Cluitmans P, Rasmussen LS, et al. Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study, ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction. Lancet. 1998;351:857-61.99 Silverstein JH, Deiner SG. Perioperative delirium and its relationship to dementia. Prog Neuropsychopharmacol Biol Psychiatry. 2013;43:108-115. Anesthesia and surgery may increase the risk of both delirium and postoperative cognitive dysfunction especially in older surgical patients.77 Moller JT, Cluitmans P, Rasmussen LS, et al. Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study, ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction. Lancet. 1998;351:857-61. Postoperative delirium is associated with worse outcomes such as longer hospital length of stay, institutionalization and functional decline.44 Marcantonio ER. Postoperative delirium: a 76-year-old woman with delirium following surgery. JAMA. 2012;308:73-81.,1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,1111 Rudolph JL, Inouye SK, Jones RN, et al. Delirium: an independent predictor of functional decline after cardiac surgery. J Am Geriatr Soc. 2010;58:643-9. Moreover, patients with delirium appear to have an increase long-term risk of death, re-admissions to the hospital, cognitive impairment up to five years after surgery and worsening quality of life.1212 Martin BJ, Buth KJ, Arora RC, et al. Delirium: a cause for concern beyond the immediate postoperative period. Ann Thorac Surg. 2012;93:1114-20.,1313 Abelha FJ, Luis C, Veiga D, et al. Outcome and quality of life in patients with postoperative delirium during an ICU stay following major surgery. Crit Care. 2013;17:R257. Postoperative cognitive dysfunction is also associated with increased mortality, premature loss of workforce and dependency on social transfer payments.88 Steinmetz J, Christensen KB, Lund T, et al. Long-term consequences of postoperative cognitive dysfunction. Anesthesiology. 2009;110:548-55.

Guidelines for the prevention and management of postoperative delirium have been suggested1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. but it is unknown whether clinicians utilize these guidelines in their practice. We used a survey to assess the portuguese anesthesiologists’ perspectives on adverse postoperative cognitive disorders, identify knowledge gaps and define routine clinical practice among Portugal's anesthesiologists to aid in identification, prevention and treatment of postoperative delirium and postoperative cognitive dysfunction in both attendings and residents.

Methods

Approval for this study (protocol number 2016.118 [102-DEFI/098-CES]) was provided by the Ethical Committee (Comissão de Ética para a Saúde – CES) of Centro Hospitalar do Porto, Portugal (Chairperson Drª Luisa Bernardo) on June 20th 2016. The Ethical Committee waived the requirement for informed consent for participation in the web-based survey. With permission from the authors, we created a survey on a web-based platform based on a previously validated survey by Jildenstal et al.1515 Jildenstal PK, Rawal N, Hallen JL, et al. Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey. Ann Med Surg (Lond). 2014;3:100-7.

The survey was first translated from English to portuguese by three residents and three attendings and then modified to better reflect the clinical practice and nomenclature in Portugal (Table 1). The survey was divided in three sections: (1) Demographic data; (2) Questions regarding knowledge, subjective preferences and routine clinical practices; and (3) Management of clinical cases. The three main topics of interest were: (1) Preoperative evaluation, risk assessment and risk factors for postoperative cognitive disorders; (2) Intraoperative management and monitoring of anesthesia depth; (3) Prevention and management of postoperative delirium and follow-up of patients with postoperative cognitive dysfunction. The survey included 21 questions and the answers were either presented in a Likert-scale from 1 to 5 (completely disagree, disagree, no opinion, partly agree, completely agree), or as close-ended, multiple-choice yes/no/don’t know options. Respondents had to answer all questions in order for the survey to be validated.

Table 1
Detailed survey results.

The survey was available online from September 2016 to January 2017 and a total of three reminders were sent. Potential survey respondents were anesthesiologists working in hospitals affiliated with the portuguese national health system (1121 anesthesiologists, including 291 residents) and anesthesiologists working solely in the private sector (200 anesthesiologists).1616 Lemos LJP, Viana J, Assunção JP, et al. Censos anestesiologia – 2014 | Relatório final Census anesthesiology – 2014 | Final report board of the Portuguese Anesthesiology of the Portuguese Medical Association. Rev Soc Port Anestesiol. 2015;24:41-52. In Portugal it is possible to work solely in hospitals affiliated with the portuguese national health system, solely in private hospitals, or both. Potential participants were contacted through an e-mail that included a brief introductory note, instructions, a link to the survey and the authors’ contact information. Participation was voluntary and anonymous. The national Anesthesiologist's Society sent the link with the survey through their mailing database to active members and maintained its availability on their official website throughout the 5 month period. To increase response rate, we emailed the Heads of all Anesthesiology Departments of the national health system affiliated hospitals so they could incentivise participation and forward the survey to anesthesiologists working in their departments.

We used the IBM SPSS Statistics for Mac OS, version 24.0 (IBM Corp., Armonk, N.Y., USA) to perform the statistical data analysis. Demographic data and results for the multiple-choice questions are presented as frequency and percentage. Responses for the Likert scale questions are presented as frequency and percentage calculated as the number of a positive (4 – Partly agree; 5 – Completely agree) or negative (1 – Completely disagree; 2 – Disagree) finding. A secondary analysis was conducted to compare results of the Likert scale questions between residents and attendings using the Mann–Whitney test for ordinal variables. Results are shown in mean ± Standard Deviation (SD) and two-sided statistical significance was set at 0.05.

Results

We analyzed 234 surveys (17.7% of the total potential respondents). Most anesthesiologists were female 158 (67.5%), worked in a teaching hospital 207 (88.5%) and were attendings 172 (73.5%). The comprehensive survey results are shown in Table 1 and detailed demographic data is in Table 2.

Table 2
Demographic characteristics.

When anesthesiologists were asked if they were to have surgery under general anesthesia, 58.9% (n = 138) would be concerned about possible postoperative cognitive impairment and 94% (n = 220) noted that they would want depth of anesthesia to be monitored. This was more pronounced amongst residents (4.83 ± 0.54 vs. 4.63 ± 0.74; p = 0.019). Most of them would prefer regional techniques anesthesia for inguinal hernia repair (60.3% (n = 141)).

The majority of participants agreed that risk of postoperative cognitive disorders should be considered when choosing the type of anesthesia (105 (87.6%)) and that preoperative cognitive assessment should be routinely performed (184 (78.6%)). Nevertheless, the risk of adverse postoperative cognitive disorders was perceived as less important when compared to adverse cardiac 224 (95.8%) and pulmonary 228 (97.4%) complications. Management of postoperative pain (4.79 ± 0.52 vs. 4.54 ± 0.72; p = 0.011) and the patient choice for the anesthesia plan (4.19 ± 0.76 vs. 3.94 ± 0.93; p = 0.043) were more important to residents when compared to attendings (Fig. 1). In the preoperative evaluation, the risk of awareness was valued the most by almost all 228 (97.4%) respondents, followed by postoperative cognitive dysfunction 196 (83.8%), postoperative delirium 188 (80.3%) and emergence agitation 161 (68.8%). Concern for awareness was higher amongst residents than attendings (4.86 ± 0.35 vs. 4.61 ± 0.64; p = 0.005) (Fig. 2). Risk factors thought to be most predictive of postoperative cognitive disorders were: age (229 [97.9%]), major surgery (222 [94.9%]), alcoholism (220 [94%]) and previous stroke (207 [88.4%]). Male gender (78 [33.3%]) and lower education (107 [45.8%]) were considered less important risk factors (Fig. 3). Most hospitals did not have written protocols regarding anxiolytic (196 [83.8%]) or analgesic (203 [86.8%]) medication in high-risk patients for adverse postoperative cognitive disorders.

Figure 1
At the time of preoperative assessment, which factors do you think should influence the choice of anesthetic?
Figure 2
During preoperative assessment which of the following cognitive states do you take into account?
Figure 3
How important do you consider for the following risk factors in the occurrence for postoperative cognitive disorders?

When asked to propose an anesthesia plan for a patient with increased risk for postoperative delirium, 46.2% (n = 108) of respondents preferred a spinal, 19.2% (n = 45) a combined general/regional block and 14.1% (n = 33) a sequential combined spinal epidural block. In the case of a general anesthesia, 92.7% (n = 217) would use depth of anesthesia monitoring in a high-risk patient for prevention of postoperative delirium. The most used monitor was the Bispectral Index (BIS) 198 (93%). Almost all 226 (97%) of participants have processed-EEG monitors in their hospitals and 56% (n = 126) always or almost always use them. About 75% (n = 161) of anesthesiologists believe that anesthesia depth should be monitored in all patients. When asked if they would use a depth of anesthesia monitor to reduce the risk of awareness, 94% (n = 220) agreed; 86.8% (n = 161) believe that a processed-EEG monitor is a reliable method for controlling anesthesia depth and only 8% (n = 18) consider it too expensive to be used. Residents when compared to attendings, more strongly believe in the usefulness of depth of anesthesia monitors in reducing the risk of awareness (4.83 ± 0.46 vs. 4.34 ± 0.70; p = 0.007) and controlling the depth of anesthesia (4.34 ± 0.66 vs. 4.11 ± 0.73; p = 0.012) (Fig. 4).

Figure 4
What do you think about the anesthesia depth monitors?

Almost 60% (n = 140) recalled at least one episode of postoperative delirium in the last year (79.3% from 1 to 5 episodes and 6.4% more than 10 episodes) but only 15.2% (n = 35) regularly used screening tools to assess delirium after surgery. When asked how they would manage a delirious older patient in the recovery room, 62.4% (n = 146) would first administer an analgesic and 11.1% (n = 26) an anxiolytic. If the participants had to administered an anxiolytic, most would choose a benzodiazepine such as midazolam 85 (36.5%), and 33.9% (n = 79) a neuroleptic such as haloperidol. Most hospitals do not have protocols to manage patients who develop delirium in Post-Anesthesia Care Unit 129 (55.1%) or surgical wards 138 (59%). When managing a patient with postoperative cognitive dysfunction, only 4 (1.7%) had institutional written protocols. In their clinical practice, 37.2% (n = 87) of participants recall a case of postoperative cognitive dysfunction; 37.2% (n = 87) answered that patients with recent memory loss would be submitted to a neuropsychological evaluation and 44% (n = 103) would refer those patients to a neurologist or neuropsychologist for further evaluation and treatment.

Around 98% (n = 229) and 97% (n = 227) of respondents believe that postoperative delirium and postoperative cognitive dysfunction, respectively, are neglected fields in anesthesiology.

Discussion

Our results emphasize that portuguese anesthesiologists recognized postoperative cognitive disorders as important outcomes that are frequently ignored in anesthesiology. Respondents were aware of the major risk factors and most believe that it would be useful to preoperatively screen cognitive function. Depth of anesthesia monitors are available in most hospitals and are widely used. Most participants, especially residents, believe they are useful in reducing the risk of awareness and a reliable method for controlling anesthesia depth. Very few hospitals have protocols for identification, prevention and treatment of postoperative cognitive disorders.

The original survey to Swedish anesthesiologists and nurse anesthetists indicate that health care professionals are concerned about the risk of adverse postoperative cognitive disorders and the majority was not convinced about the use of monitors to control anesthesia depth. Moreover, they concluded that it is necessary to implement strategies to improve knowledge about risk factors, prevention and treatment for adverse postoperative cognitive disorders.1515 Jildenstal PK, Rawal N, Hallen JL, et al. Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey. Ann Med Surg (Lond). 2014;3:100-7.

The increased risk for postoperative cognitive disorders was perceived as an important factor to take into account when evaluating patients to undergo anesthesia and surgery, although not as important as cardiac or pulmonary events. These results are in line with the Jildenstal et al.1515 Jildenstal PK, Rawal N, Hallen JL, et al. Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey. Ann Med Surg (Lond). 2014;3:100-7. original survey results: 69% of the respondents considered the “risk for neurocognitive side effects” of importance during the preoperative assessment, while 97% and 98% considered the risk for cardiac and pulmonary events of importance, respectively. Contrary to the original survey,1515 Jildenstal PK, Rawal N, Hallen JL, et al. Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey. Ann Med Surg (Lond). 2014;3:100-7. most portuguese anesthesiologists would be concern about possible postoperative cognitive loss if having anesthesia themselves. Adverse postoperative cognitive disorders have a recognizable impact on postoperative recovery, rehabilitation and mortality.44 Marcantonio ER. Postoperative delirium: a 76-year-old woman with delirium following surgery. JAMA. 2012;308:73-81.,88 Steinmetz J, Christensen KB, Lund T, et al. Long-term consequences of postoperative cognitive dysfunction. Anesthesiology. 2009;110:548-55.,1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.1313 Abelha FJ, Luis C, Veiga D, et al. Outcome and quality of life in patients with postoperative delirium during an ICU stay following major surgery. Crit Care. 2013;17:R257. Interestingly, the patient's wish was only considered to be an important factor for the anesthesia plan by 75.6% of participants and was significantly different between residents and attendings.

We found that most portuguese anesthesiologists were concerned with awareness as an adverse outcome when proposing an anesthesia plan, especially residents. This was also observed in the Jildenstal et al.1515 Jildenstal PK, Rawal N, Hallen JL, et al. Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey. Ann Med Surg (Lond). 2014;3:100-7. study. The authors explained that this concern might be related to the general perception of a general failure in providing adequate anesthesia and the bad publicity associated with recall of intraoperative pain and/or paralysis. The incidence of awareness is 1:15,414 anesthetics,1717 Pandit JJ, Cook TM, Jonker WR, et al. A national survey of anaesthetists (NAP5 baseline) to estimate an annual incidence of accidental awareness during general anaesthesia in the UK. Br J Anaesth. 2013;110:501-9. much lower than other postoperative cognitive disorders.55 Bruce AJ, Ritchie CW, Blizard R, et al. The incidence of delirium associated with orthopedic surgery: a meta-analytic review. Int Psychogeriatr. 2007;19:197-214.,77 Moller JT, Cluitmans P, Rasmussen LS, et al. Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study, ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction. Lancet. 1998;351:857-61.,88 Steinmetz J, Christensen KB, Lund T, et al. Long-term consequences of postoperative cognitive dysfunction. Anesthesiology. 2009;110:548-55.,1818 Radtke FM, Franck M, Hagemann L, et al. Risk factors for inadequate emergence after anesthesia: emergence delirium and hypoactive emergence. Minerva Anestesiol. 2010;76:394-403. Awareness may be perceived by the anesthesiologist as a direct consequence of his anesthesia management (e.g. the patient was not receiving sufficient hypnotics) whereas postoperative delirium and postoperative cognitive dysfunction follow a much more complex and comprehensive pathogenic model.44 Marcantonio ER. Postoperative delirium: a 76-year-old woman with delirium following surgery. JAMA. 2012;308:73-81.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214.,1919 Evered L, Scott DA, Silbert B, et al. Postoperative cognitive dysfunction is independent of type of surgery and anesthetic. Anesth Analg. 2011;112:1179-85.

It is thought that delirium development follows a pathogenic model in which predisposing conditions (risk factors) and precipitant factors (stressor events) can be identified.44 Marcantonio ER. Postoperative delirium: a 76-year-old woman with delirium following surgery. JAMA. 2012;308:73-81. Not all risk factors were considered in the original survey1515 Jildenstal PK, Rawal N, Hallen JL, et al. Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey. Ann Med Surg (Lond). 2014;3:100-7. and we added others that were considered pertinent based on the previous literature.1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. The participants of this survey considered age, major surgery, alcoholism and previous stroke as the most important predictors of postoperative cognitive disorders and these results are in line with current literature.77 Moller JT, Cluitmans P, Rasmussen LS, et al. Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study, ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction. Lancet. 1998;351:857-61.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214.,2020 Girard TD, Jackson JC, Pandharipande PP, et al. Delirium as a predictor of long-term cognitive impairment in survivors of critical illness. Crit Care Med. 2010;38:1513-20.,2121 Pandharipande PP, Girard TD, Jackson JC, et al. Long-term cognitive impairment after critical illness. N Engl J Med. 2013;369:1306-16. Most respondents believed that preoperative cognitive assessment would be useful, although protocols for patients at high-risk for postoperative cognitive disorders seldom exist. Dementia and mild cognitive impairment are common in older adults and are proven independent risk factors for postoperative delirium.1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. Moreover, impaired executive function without impairments in activities of daily living is a predictor of postoperative delirium.2222 Greene NH, Attix DK, Weldon BC, et al. Measures of executive function and depression identify patients at risk for postoperative delirium. Anesthesiology. 2009;110:788-95. Cognitive impairment is also associated with worse outcomes including increased postoperative complications, longer hospital length of stay, discharge to a higher level of care, persistent postoperative cognitive dysfunction and mortality after surgery.2323 Heng M, Eagen CE, Javedan H, et al. Abnormal mini-cog is associated with higher risk of complications and delirium in geriatric patients with fracture. J Bone Joint Surg Am. 2016;98:742-50.2727 Silbert B, Evered L, Scott DA, et al. Preexisting cognitive impairment is associated with postoperative cognitive dysfunction after hip joint replacement surgery. Anesthesiology. 2015;122:1224-34. Cognitive impairment often goes unrecognized unless formally assessed and several guidelines recommend screening older patients before surgery.1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214.,2828 Ganguli M, Rodriguez E, Mulsant B, et al. Detection and management of cognitive impairment in primary care: the steel valley seniors survey. J Am Geriatr Soc. 2004;52:1668-75.3131 Partridge JS, Dhesi JK, Cross JD, et al. The prevalence and impact of undiagnosed cognitive impairment in older vascular surgical patients. J Vasc Surg. 2014;60, 1002-11.e1003. There are multiple quick and easy preoperative cognitive screening tools available that can be used to highlight patients at risk for adverse postoperative outcomes, including postoperative delirium.3232 Axley MS, Schenning KJ. Preoperative Cognitive and frailty screening in the geriatric surgical patient: a narrative review. Clin Ther. 2015;37:2666-75.,3333 Long LS, Shapiro WA, Leung JM. A brief review of practical preoperative cognitive screening tools. Can J Anaesth. 2012;59:798-804.

The precipitating factors are potentially modifiable factors associated with hospitalization and with the intra and postoperative periods. Guidelines recommended the use of electroencephalographic monitors of anesthetic depth to avoid burst suppression and unnecessary deep anesthesia to prevent postoperative delirium.1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. In contrast to the Jildenstal et al.,1515 Jildenstal PK, Rawal N, Hallen JL, et al. Perioperative management in order to minimise postoperative delirium and postoperative cognitive dysfunction: Results from a Swedish web-based survey. Ann Med Surg (Lond). 2014;3:100-7. these results show that there is a monitor available in almost every hospital; most participants always or almost always use them; and they don’t believe they are too expensive to be used. Residents strongly agree that depth of anesthesia monitors may reduce the risk of awareness and are a reliable method for controlling anesthesia depth. Interestingly, 94% of anesthesiologists would like a depth of anesthesia monitor to be used if they were undergoing general anesthesia but only 75% agreed they should be used in all patients undergoing anesthesia. It is unknown if participants were worried about awareness or the development of postoperative cognitive disorders. Evidence suggests that a deeper anesthesia state or longer time in burst suppression might be associated with an increased risk of postoperative delirium and postoperative cognitive dysfunction.3434 Moyce Z, Rodseth RN, Biccard BM. The efficacy of peri-operative interventions to decrease postoperative delirium in non-cardiac surgery: a systematic review and meta-analysis. Anaesthesia. 2014;69:259-69.3939 Deiner S, Luo X, Silverstein JH, et al. Can intraoperative processed EEG predict postoperative cognitive dysfunction in the elderly?. Clin Ther. 2015;37:2700-5. Intraoperative monitoring may reduce the risk postoperative delirium and postoperative cognitive dysfunction4040 Radtke FM, Franck M, Lendner J, et al. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesth. 2013;110:i98-105.,4141 Chan MT, Cheng BC, Lee TM, et al. BIS-guided anesthesia decreases postoperative delirium and cognitive decline. J Neurosurg Anesthesiol. 2013;25:33-42. but its usefulness on preventing awareness is still controversial.4242 Shepherd J, Jones J, Frampton G, et al. Clinical effectiveness and cost-effectiveness of depth of anaesthesia monitoring (E-Entropy, Bispectral Index and Narcotrend): a systematic review and economic evaluation. Health Technol Assess. 2013;17:1-264.,4343 Avidan MS, Jacobsohn E, Glick D, et al. Prevention of intraoperative awareness in a high-risk surgical population. N Engl J Med. 2011;365:591-600.

Our results also showed that protocols for managing patients at risk for postoperative cognitive disorders are rarely used although dedicated pathways improve quality of care and outcomes in the geriatric surgical population.1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,3030 Chow WB, Rosenthal RA, Merkow RP, et al. Optimal preoperative assessment of the geriatric surgical patient: a best practices guideline from the American College of Surgeons National Surgical Quality Improvement Program and the American Geriatrics Society. J Am Coll Surg. 2012;215:453-66. Delirium may be unrecognized in up to 50% of the times, so clinicians should have a high suspicion degree, especially in the case of vulnerable patients.44 Marcantonio ER. Postoperative delirium: a 76-year-old woman with delirium following surgery. JAMA. 2012;308:73-81. According to the recent European Society of Anesthesiologists guidelines, patients should not leave the recovery room without being screened for postoperative delirium.1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. Although the gold standard to diagnose delirium is a psychiatric evaluation according to the DMS criteria, the Confusion Assessment Method or the Nursing Delirium Screening Scale can be used effectively.66 Whitlock EL, Vannucci A, Avidan MS. Postoperative delirium. Minerva Anestesiol. 2011;77:448-56.,4444 De J, Wand AP. Delirium screening: a systematic review of delirium screening tools in hospitalized patients. Gerontologist. 2015;55:1079-99. More than half of the participants recalled at least one episode of postoperative delirium in the last year but only 6% of respondents recalled more than ten. This might indicate that portuguese anesthesiologist are aware of the importance and implications of adverse postoperative cognitive disorders on older patient's outcomes but are unable to recognize every case in clinical practice.

When managing a patient with postoperative delirium in the recovery room, most said they would either give first an analgesic or an analgesic in combination with an anxiolytic. Both pain and opioids are known risk factors for delirium and an adequate pain assessment and treatment is highly recommended.1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. If they were to administer an anxiolytic, most stated that a benzodiazepine would be their first choice. Benzodiazepines are well known precipitating factors for delirium and should be avoided, particularly in older patients.1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. Current evidence supports antipsychotics for the treatment of patients who are severely agitated or distressed, and are threatening substantial harm to self and others.1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214. Above all, recommendations highlight the importance of performing a medical evaluation, making medication and environmental adjustments and ordering appropriate diagnostic tests to identify and manage underlying contributors to delirium.1010. Postoperative delirium in older adults: best practice statement from the American Geriatrics Society. J Am Coll Surg. 2015;220:136-48.,1414 Aldecoa C, Bettelli G, Bilotta F, et al. European Society of Anaesthesiology evidence-based and consensus-based guideline on postoperative delirium. Eur J Anaesthesiol. 2017;34:192-214.

The limitations to this study are inherent to its methodology. The survey was sent through the mailing list of professional organizations and institutions. As the list of members is dynamic and often incomplete, the sample of potential survey respondents was certainly not achieved and we had no mechanism to ensure that participants only completed the survey once. The rate of non-responders might have led to nonresponse bias and those with more interest in the topic will more readily participate (self-selection and participation bias). Although the demographic characteristics of participants were similar to the potential survey respondents, participation was geographically uneven.1616 Lemos LJP, Viana J, Assunção JP, et al. Censos anestesiologia – 2014 | Relatório final Census anesthesiology – 2014 | Final report board of the Portuguese Anesthesiology of the Portuguese Medical Association. Rev Soc Port Anestesiol. 2015;24:41-52. Moreover, this survey was intended to gain insight how anesthesiologists manage cases and the answers may differ from actual practice. Nevertheless, this survey was based on a previously validated questionnaire made to the Swedish health care professionals, where results were overall similar. This study was conducted to understand the portuguese anesthesiologists’ perspectives on postoperative delirium and postoperative cognitive dysfunction and, as so, it contributes for further understanding current clinical practice in Portugal. These results will serve as background for future interventions to prevent and manage postoperative cognitive disorders.

In conclusion, portuguese anesthesiologists perceive postoperative cognitive disorders as important adverse outcomes following surgery and anesthesia are aware of the main risk factors but may lack some information on prevention and management of postoperative delirium. Most hospitals have depth of anesthesia monitors available and those are used by most participants but efforts should be made to increase its usage, especially in high risk patients for postoperative cognitive disorders. The majority of hospitals do not have protocols regarding preoperative cognitive assessment, diagnosis, management and follow-up of patients with delirium and postoperative cognitive dysfunction. Dedicated pathways for older surgical patients may improve outcomes and, as so, it is important to identify high-risk patients and establish preventive interventions.

Acknowledgements

This study was scientifically supported by the portuguese Society of Anesthesiologists (SPA). The authors would like to acknowledge the portuguese Society of Anesthesiologists (SPA) for sending the surveys through their mailing database.

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Publication Dates

  • Publication in this collection
    Sep-Oct 2018

History

  • Received
    9 Oct 2017
  • Accepted
    27 Feb 2018
Sociedade Brasileira de Anestesiologia R. Professor Alfredo Gomes, 36, 22251-080 Botafogo RJ Brasil, Tel: +55 21 2537-8100, Fax: +55 21 2537-8188 - Campinas - SP - Brazil
E-mail: bjan@sbahq.org