Preoperative predictors of delirium after cardiac surgery: a preliminary study

Risk factors of delirium after cardiac surgery: a systematic review and meta-analysis

BACKGROUND

Post-operative delirium (POD) is a relatively common occurrence following surgical procedures, particularly cardiac surgeries. Given that the majority of pharmacologic treatments for delirium have demonstrated inadequate efficacy, it is of great importance to identify risk factors to prevent delirium or reduce its complications. Consequently, in this systematic review and meta-analysis, we identified risk factors of POD after cardiac surgery.

METHOD

A comprehensive search of the literature was conducted using the databases Scopus, PubMed, and Web of Science from the inception to April 22, 2024. The objective was to identify prospective cohorts that had assessed the risk factors associated with POD in patients undergoing cardiac surgery using multivariate regression.

RESULTS

Of the 3,166 studies that were initially screened, 23 were included in the review. Nine risk factors were evaluated including age (OR 1.06, 95% CI (1.04, 1.08), p < 0.001), pre-operative depression (OR 3.71, 95% CI (2.45, 5.62), p < 0.001), post-operative atrial fibrillation (AF) (OR 2.39, 95% CI (1.79, 3.21), p < 0.001), hypertension (HTN) (OR 1.64, 95% CI (0.75, 3.56), p = 0.212), age ≥ 65 (OR 3.32, 95% CI (2.40, 4.60), p < 0.001), pre-operative AF (OR 4.43, 95% CI (2.56, 7.69), p < 0.001), diabetes mellitus (OR 2.16, 95% CI (1.39, 3.35), p = 0.001), combined coronary artery bypass graft (CABG) + valve surgery (OR 2.73, 95% CI (1.66, 4.49), p < 0.001), and cardiopulmonary bypass (CPB) time (OR 1.02, 95% CI (1.01, 1.04), p = 0.001).

CONCLUSIONS

A total of nine risk factors were evaluated, from which eight were found to have a statistically significant effect on the risk of developing POD. These factors can be employed to more effectively identify at-risk patients and to prevent the occurrence of POD. Furthermore, this approach can facilitate earlier diagnosis and more effective patient care.

Relationship Between Coronary Artery Revascularization and Postoperative Delirium: Progress and Perspectives

Brain dysfunction resulting from damage to the heart-brain link leads to a decline in cognitive function. This, in turn, gives rise to the clinical symptom of perioperative delirium in patients undergoing coronary artery revascularization. Those affected are provided symptomatic treatment, but many do not recover fully. Thus, medium- and long-term mortality and adverse event rates remain relatively high in patients with perioperative delirium. Despite the relatively high incidence of perioperative delirium in patients undergoing coronary artery revascularization, it has not been systematically investigated. Inflammation, vascular damage, neuronal damage, and embolism are all involved in the injury process. Here, we discuss the incidence rate, pathological mechanisms, and prognosis of delirium after coronary artery revascularization. We also discuss in detail the risk factors for delirium after coronary artery revascularization, such as anxiety, depression, mode of operation, and drug use. We hope that prevention, early diagnosis, assessment, and potential treatment can be achieved by cardiologists to improve patient prognosis.

Efficacy of combined use of Suvorexant and Ramelteon in preventing postoperative delirium: a retrospective comparative study

BACKGROUND

Suvorexant and ramelteon have been presented as useful for preventing postoperative delirium. Previous studies reported on the comparison with benzodiazepine hypnotics which have been known for the risk for inducing delirium, but the comparison with patients not taking any hypnotics has not been reported yet. Therefore, we assessed the incidence rates for postoperative delirium comparing cancer patients who received preoperative combined administration with suvorexant and ramelteon and those not taking any hypnotics.

METHODS

Among 110 cancer patients who underwent surgeries at the Division of Hepato-Biliary-Pancreatic Surgery at the Shizuoka Cancer Center between April 1, 2017 and June 30, 2020, 50 patients who received combined administration with suvorexant and ramelteon from 7 days prior to their surgeries and 60 patients who did not take any hypnotics including suvorexant and ramelteon were classified. They were retrospectively observed during the 7 days from their surgeries onward to compare the cumulative incidence rates for postoperative delirium.

RESULTS

The cumulative incidence rate for postoperative delirium during the 7 days in the combined-administration group was 14.0% (7/50), while that for the no-hypnotic group was 36.7% (22/60), which proved that the incidence rate for the former was significantly low (OR: 0.28, 95%CI: 0.11-0.73, P = 0.009).

CONCLUSIONS

The present study suggests that the preventive combined administration with suvorexant and ramelteon starting from the preoperative period for cancer patients can be effective in lowering the incidence rate for postoperative delirium.

TRIAL REGISTRATION

Retrospectively registered.

Effects of inflammation and oxidative stress on postoperative delirium in cardiac surgery

The past decade has witnessed unprecedented medical progress, which has translated into cardiac surgery being increasingly common and safe. However, complications such as postoperative delirium remain a major concern. Although the pathophysiological changes of delirium after cardiac surgery remain poorly understood, it is widely thought that inflammation and oxidative stress may be potential triggers of delirium. The development of delirium following cardiac surgery is associated with perioperative risk factors. Multiple interventions are being explored to prevent and treat delirium. Therefore, research on the potential role of biomarkers in delirium as well as identification of perioperative risk factors and pharmacological interventions are necessary to mitigate the development of delirium.

Relationship between preoperative anxiety and onset of delirium after cardiovascular surgery in elderly patients: focus on personality and coping process

BACKGROUND

Postoperative delirium is associated with increased mortality. Therefore, it is important to manage delirium during the entire perioperative period. Preoperative anxiety is associated with poor prognosis in postoperative patients who have undergone cardiovascular surgery. This study aims to investigate the relationship between preoperative anxiety and onset of delirium after cardiovascular surgery in elderly patients (aged 65 years or older), considering the individual psychological characteristics, such as personality and stress coping skills in response to anxiety, as confounding factors.

METHODS

This prospective study included patients aged >65 years in a preoperative state before undergoing cardiovascular surgery. Subjects were divided into two groups based on whether they experienced postoperative delirium, or not. We compared clinical and demographic factors, preoperative psychiatric and psychological factors, and intraoperative and perioperative physical factors between the control and delirium groups. Multiple imputations were used to account for missing data.

RESULTS

Out of 168 subjects enrolled in this study, 26 (15.5%) developed postoperative delirium. Univariate analysis showed significant differences in age (P = 0.027), cognitive function (P = 0.007), agreeableness (P = 0.029), and the Acute Physiology and Chronic Health Evaluation-II (APACHE-II) score (P = 0.023) between the delirium and control groups. Multiple logistic regression analysis did not identify a significant association between preoperative anxiety and the onset of postoperative delirium. However, age (odds ratio (OR) = 1.114, P = 0.018), agreeableness (OR = 0.555, P = 0.008), and the APACHE-II score (OR = 1.227, P = 0.008) were identified as risk factors for postoperative delirium.

CONCLUSION

Agreeableness, one of the personality traits associated with preoperative anxiety, appears to be involved in the development of postoperative delirium as an independent psychological factor, regardless of age or physical factors.

Oxidative stress and soluble receptor for advanced glycation end-products play a role in the pathophysiology of delirium after cardiac surgery

Coronary-artery bypass graft (CABG) surgery is known to improve cardiac function and decrease mortality, albeit, this method of treatment is also associated with a neuropsychiatric complications including postoperative delirium. The pathophysiology of delirium after cardiac surgery remains poorly understood. Thus, the purpose of this study was to investigate whether oxidative stress reflected by decreased preoperative and postoperative plasma antioxidant activity is independently associated with delirium after cardiac surgery. The second aim was to assess whether decreased antioxidant activity is stress-related or mediated by other pathologies such as major depressive disorder (MDD), anxiety disorders, and cognitive impairment. Furthermore, the putative relationship between pre- and postoperative soluble receptor for advanced glycation end-products (sRAGE) overexpression and plasma antioxidant capacity was evaluated. The patients cognitive status was assessed 1 day preoperatively with the use of the Mini-Mental State Examination Test and the Clock Drawing Test. A diagnosis of MDD and anxiety disorders was established on the basis of DSM-5 criteria. Blood samples for antioxidant capacity and sRAGE levels were collected both preoperatively and postoperatively. The Confusion Assessment Method for the Intensive Care Unit was used within the first 5 days postoperatively to screen for a diagnosis of delirium. Postoperative delirium was diagnosed in 34% (61 of 177) of individuals. Multivariate logistic regression analysis revealed that low baseline antioxidant capacity was independently associated with postoperative delirium development. Moreover, increased risk of delirium was observed among patients with a preoperative diagnosis of MDD associated with antioxidant capacity decreased postoperatively. According to receiver operating characteristic analysis, the most optimal cutoff values of the preoperative and postoperative antioxidant capacity that predict the development of delirium were 1.72 mM and 1.89 mM, respectively. Pre- and postoperative antioxidant capacity levels were negatively correlated with postoperative sRAGE concentration (Spearman's Rank Correlation − 0.198 and − 0.158, p < 0.05, respectively). Patients with decreased preoperative antioxidant activity and those with depressive episodes complicated with lower postoperative antioxidant activity are at significantly higher risk of delirium after cardiac surgery development. sRAGE overexpression may be considered as protective mechanism against increased oxidative stress and subsequent cell damage.

Target-Controlled Anesthesia Reduces Postoperative Delirium in Spinal Surgical Patients: A Prospective Pilot Study

The aim of this pilot study was to examine the effect of combined target-controlled anesthesia and manually controlled anesthesia on the incidence of postoperative delirium (POD) in patients undergoing spinal surgery. All of the patients were enrolled before spinal surgery and divided into 2 groups at random: one group received combined sevoflurane target-controlled inhalation and sufentanil target-controlled infusion (S-S TCI group), whereas the other received combined manually controlled sevoflurane inhalation and sufentanil infusion (S-S MCI group). Data related to preoperative factors, perioperative factors, and postoperative data were retrospectively collected. Compared with the S-S MCI group, the dosage of vasoactive drugs after surgery, postoperative recovery time, time to cannula removal, and the incidence of POD were significantly decreased in the S-S TCI group (P &lt; 0.05). Overall, POD appeared in 81 patients (16.8%) by postoperative day 3. Multiple regression analysis showed that postoperative blood loss and manually controlled anesthesia were risk factors for POD in spinal surgery patients. Therefore, prophylactic blood transfusion and phenylephrine can reduce the incidence of POD in the presence of postoperative hypotension. Target-controlled anesthesia may improve the quality of anesthesia as well as reduce POD in spinal surgical patients. These results provide clinical evidence for improving the prevention, diagnosis, and management of POD.

Delirium and depression in cardiac surgery: A comprehensive review of risk factors, pathophysiology, and management

BACKGROUND

Mental health and wellbeing continue to gain more attention as they are inextricably associated with clinical outcomes, particularly quality of life. Many medical ailments and major surgeries affect patients' mental health, including depression and delirium.

AIMS

The objective of this manuscript was to comprehensively review and critically examine the literature pertaining to cardiac surgery, depression, and delirium.

METHODS

This is a narrative review article. We performed our search analysis by using the following key words: "Cardiac Surgery", "Depression", "Delirium", "Clinical outcomes", and "Mental Health". Search analysis was done on MedLine PubMed, accessing indexed peer-reviewed publications.

RESULTS

Cardiac Surgery is a life-altering intervention indicated to improve morbidity and mortality in patients with cardiovascular diseases. Psychiatric conditions before and after cardiac surgery worsen patient prognosis and increase mortality rate. Specifically, preoperative depression increases postoperative depression and is associated with impaired functional status, slow physical recovery, and an increased readmission rate.

DISCUSSION

Although the exact pathophysiology between depression and cardiovascular disease (CVD) is unknown, several pathways have been implicated. Unmanaged depression can also lead to other psychological conditions such as delirium. Like depression, the exact association between delirium and CVD is not well understood, but believed to be multifactorial.

CONCLUSION

Herein, we provide a comprehensive review of the links between depression, delirium, and cardiovascular surgery. We critically examine the current data that pertains to the pathophysiology of these debilitating mental health issues in the context of cardiac surgery. Finally, we summarize the various treatment options available for managing depression and delirium in the cardiac surgery patient population.

Elevated Monocyte Chemoattractant Protein-1 as the Independent Risk Factor of Delirium after Cardiac Surgery. A Prospective Cohort Study

BACKGROUND

The pathogenesis of postoperative delirium is largely unknown. The primary objective of this study is to assess whether increased levels of monocyte chemoattractant protein-1 (MCP-1) and high-sensitivity C-reactive protein (hsCRP) are associated with postoperative delirium in patients who have undergone cardiac surgery. The secondary objective is to investigate whether any association between raised inflammatory biomarkers levels and delirium is related to surgical and anesthetic procedures or mediated by pre-existing psychiatric conditions associated with raised pro-inflammatory markers levels.

METHODS

The patients were screened for cognitive impairment one day preoperatively with the use of the Mini-Mental State Examination Test and the Clock Drawing Test. A diagnosis of major depressive disorder (MDD) and anxiety disorders was established on the basis of Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria. Blood samples were collected pre- and postoperatively for hsCRP and chemokine levels.

RESULTS

Postoperative delirium developed in 34% (61 of 177) of patients. Both pre- and postoperative hsCRP, and preoperative MCP-1 levels were associated with postoperative delirium in univariate comparisons; p = 0.001; p < 0.001; p < 0.001, respectively. However, according to a multivariable logistic regression analysis, only a raised MCP-1 concentration before surgery was independently associated with postoperative delirium, and related to advancing age, preoperative anxiety disorders and prolonged intubation.

CONCLUSIONS

The present study suggests that an elevated preoperative MCP-1 concentration is associated with delirium after cardiac surgery. Monitoring of this inflammatory marker may reveal the cardiovascular disease (CVD) patients who are at risk of neuropsychiatric syndromes development.

Development and validation of a predictive score for ICU delirium in critically ill patients

Background

The incidence of delirium in intensive care unit (ICU) patients is high and associated with a poor prognosis. We validated the risk factors of delirium to identify relevant early and predictive clinical indicators and developed an optimized model.

Methods

In the derivation cohort, 223 patients were assigned to two groups (with or without delirium) based on the CAM-ICU results. Multivariate logistic regression analysis was conducted to identify independent risk predictors, and the accuracy of the predictors was then validated in a prospective cohort of 81 patients.

Results

A total of 304 patients were included: 223 in the derivation group and 81 in the validation group, 64(21.1%)developed delirium. The model consisted of six predictors assessed at ICU admission: history of hypertension (RR = 4.367; P = 0.020), hypoxaemia (RR = 3.382; P = 0.018), use of benzodiazepines (RR = 5.503; P = 0.013), deep sedation (RR = 3.339; P = 0.048), sepsis (RR = 3.480; P = 0.018) and mechanical ventilation (RR = 3.547; P = 0.037). The mathematical model predicted ICU delirium with an accuracy of 0.862 (P < 0.001) in the derivation cohort and 0.739 (P < 0.001) in the validation cohort. No significant difference was found between the predicted and observed cases of ICU delirium in the validation cohort (P > 0.05).

Conclusions

Patients’ risk of delirium can be predicted at admission using the early prediction score, allowing the implementation of early preventive interventions aimed to reduce the incidence and severity of ICU delirium.

The relationship between intraoperative cerebral oximetry and postoperative delirium in patients undergoing off-pump coronary artery bypass graft surgery: a retrospective study

Background

Cerebral oximetry has been widely used to measure regional oxygen saturation in brain tissue, especially during cardiac surgery. Despite its popularity, there have been inconsistent results on the use of cerebral oximetry during cardiac surgery, and few studies have evaluated cerebral oximetry during off pump coronary artery bypass graft surgery (OPCAB).

Methods

To evaluate the relationship between intraoperative cerebral oximetry and postoperative delirium in patients who underwent OPCAB, we included 1439 patients who underwent OPCAB between October 2004 and December 2016 and among them, 815 patients with sufficient data on regional cerebral oxygen saturation (rSO₂) were enrolled in this study. We retrospectively analyzed perioperative variables and the reduction in rSO₂ below cut-off values of 75, 70, 65, 60, 55, 50, 45, 40, and 35%. Furthermore, we evaluated the relationship between the reduction in rSO₂ and postoperative delirium.

Results

Delirium occurred in 105 of 815 patients. In both univariable and multivariable analyses, the duration of rSO₂ reduction was significantly longer in patients with delirium at cut-offs of < 50 and 45% (for every 5 min, adjusted odds ratio (OR) 1.007 [95% Confidence interval (CI) 1.001 to 1.014] and adjusted OR 1.012 [1.003 to 1.021]; p = 0.024 and 0.011, respectively). The proportion of patients with a rSO₂ reduction < 45% was significantly higher among those with delirium (adjusted OR 1.737[1.064 to 2.836], p = 0.027).

Conclusions

In patients undergoing OPCAB, intraoperative rSO₂ reduction was associated with postoperative delirium. Duration of rSO₂ less than 50% was 40% longer in the patients with postoperative delirium. The cut-off value of intraoperative rSO₂ that associated with postoperative delirium was 50% for the total patient population and 55% for the patients younger than 68 years.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12871-020-01180-x.

Physical Performance and Risk of Postoperative Delirium in Older Adults Undergoing Aortic Valve Replacement

Background

Delirium is a major risk factor for poor recovery after surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR). It is unclear whether preoperative physical performance tests improve delirium prediction.

Objective

To examine whether physical performance tests can predict delirium after SAVR and TAVR, and adapt an existing delirium prediction rule for cardiac surgery, which includes Mini-Mental State Examination (MMSE), depression, prior stroke, and albumin level.

Design

Prospective cohort, 2014-2017.

Setting

Single academic center.

Subjects

A total of 187 patients undergoing SAVR (n=77) or TAVR (n=110).

Methods

The Short Physical Performance Battery (SPPB) score was calculated based on gait speed, balance, and chair stands (range: 0-12 points, lower scores indicate poor performance). Delirium was assessed using the Confusion Assessment Method. We fitted logistic regression to predict delirium using SPPB components and risk factors of delirium.

Results

Delirium occurred in 35.8% (50.7% in SAVR and 25.5% in TAVR). The risk of delirium increased for lower SPPB scores: 10-12 (28.2%), 7-9 (34.5%), 4-6 (37.5%) and 0-3 (44.1%) (p-for-trend=0.001). A model that included gait speed <0.46 meter/second (OR, 2.7; 95% CI, 1.2-6.4), chair stands time ≥11.2 seconds (OR, 3.5; 95% CI, 1.0-12.4), MMSE <24 points (OR, 2.9; 95% CI, 1.3-6.4), isolated SAVR (OR, 5.4; 95% CI, 2.1-13.8), and SAVR and coronary artery bypass grafting (OR, 15.8; 95% CI, 5.5-45.7) predicted delirium better than the existing prediction rule (C statistics: 0.71 vs 0.61; p=0.035).

Conclusion

Assessing physical performance, in addition to cognitive function, can help identify high-risk patients for delirium after SAVR and TAVR.

Delirium Post-Stroke: Short- and Long-Term Effect on Depression, Anxiety, Apathy and Aggression (Research Study-Part of PROPOLIS Study)

Background: Stroke patients are particularly vulnerable to delirium episodes, but very little is known about its subsequent adverse mental health outcomes. The author’s objective was to explore the association between in-hospital delirium and depression, anxiety, anger and apathy after stroke. Methods: A total of 750 consecutive patients with acute stroke or transient ischemic attack, were screened for delirium during hospitalization. Patients underwent mental health evaluation in hospital, 3 and 12 months post-stroke; depression, apathy, anxiety and anger were the outcomes measured at all evaluation check points. Results: Delirium was an independent risk factor for depression (OR = 2.28, 95%CI 1.15–4.51, p = 0.017) and aggression (OR = 3.39, 95%CI 1.48–7.73, p = 0.004) at the hospital, for anxiety 3 months post-stroke (OR = 2.83, 95%CI 1.25–6.39, p = 0.012), and for apathy at the hospital (OR = 4.82, 95%CI 2.25–10.47, p < 0.001), after 3 (OR = 3.84, 95%CI 1.31–11.21, p = 0.014) and 12 months (OR = 4.95, 95%CI 1.68–14.54, p = 0.004) post stroke. Conclusions: The results of this study confirm, that mental health problems are very frequent complications of stroke. Delirium in the acute phase of stroke influences mental health of patients. This effect is especially significant in the first months post-stroke and vanishes with time, which suggests that in-hospital delirium might not be a damaging occurrence in most measures of mental health problems from a long-term perspective.

Preoperative Depression and Plasma Cortisol Levels as Predictors of Delirium after Cardiac Surgery

BACKGROUND

Delirium is common in old patients who undergo cardiac surgery, and it is associated with adverse outcomes. The genesis of delirium is thought to be multi-factorial, but it is still not well understood. Symptoms of depression and elevated cortisol level have been described in some previous studies as factors associated with delirium, suggesting a shared pathophysiology.

AIMS

The objective of the present study was to determine whether preoperative depression symptoms and increased cortisol level represent risk factors for delirium after cardiac surgery.

METHODS

We performed a prospective cohort study in 183 patients aged >50 years undergoing elective cardiac surgery. The Geriatric Depression Scale (GDS) was used to assess patients for depressive symptoms before surgery. Preoperative plasma cortisol levels were available in 145 participants. Delirium was diagnosed using the Confusion Assessment Method for Intensive Care Unit (CAM-ICU) during the first 7 days after surgery. Spearman correlation was used for correlations between GDS, Mini-Mental State Examination (MMSE), Charlson comorbidity index, and age. Binary logistic regression was used to determine whether GDS and cortisol levels predict postoperative delirium.

RESULTS

Delirium occurred in 60 patients out of 183 (32.8%) included and lasted 2.3 days (SD 1.36). GDS was correlated with age (p = 0.001) and comorbidity index (p = 0.003) and inversely correlated with MMSE score (p < 0.001). Higher preoperative GDS scores were associated with incidence of delirium in the postoperative period (p = 0.002). The association was significant after controlling for age, MMSE score, history of stroke, and Charlson comorbidity index (p = 0.045). Preoperative cortisol level was not associated with the development of postoperative delirium.

CONCLUSION

Our results suggest that a higher preoperative depression score is associated with an increased risk of postoperative delirium. On the other hand, preoperative plasma cortisol level does not seem to be a predictor of delirium after surgery. Further studies are needed to determine the potential of preoperative depression treatment to prevent postoperative delirium.

Effect of atorvastatin on delirium status of patients in the intensive care unit: a randomized controlled trial

INTRODUCTION

Delirium is one of the most prevalent complications in intensive care unit (ICU) patients, which is related to worse clinical outcomes including a longer ICU stay, longer duration of mechanical ventilation, higher mortality rates and increased risk of cognitive impairment. Observational studies have suggested that statins might have a positive effect on delirium status of hospitalized patients. To date, there has been no trial assessing the effect of atorvastatin on delirium status in critically ill patients. Thus, the aim of the current study was to determine the efficacy of atorvastatin on delirium status of patients in the ICU.

METHODS

In this randomized, double-blind and controlled trial, a total of 90 patients in the general ICU who had delirium for at least 2 days were randomly divided into atorvastatin (40 mg/day) (n = 40) and control (n = 50) groups. Delirium status of the patients was determined twice a day at 10:00 a.m. and 18:00 p.m. using the Richmond Agitation-Sedation Scale (RASS).

RESULTS

Administration 40 mg/day of atorvastatin significantly reduced the mean RASS score and increased delirium-free days at both morning and afternoon time points compared to the control group (p < 0.05).

CONCLUSIONS

Administration of atorvastatin had a significant positive effect on delirium status in patients admitted to the ICU.

Best Practices for Postoperative Brain Health: Recommendations From the Fifth International Perioperative Neurotoxicity Working Group

As part of the American Society of Anesthesiology Brain Health Initiative goal of improving perioperative brain health for older patients, over 30 experts met at the fifth International Perioperative Neurotoxicity Workshop in San Francisco, CA, in May 2016, to discuss best practices for optimizing perioperative brain health in older adults (ie, >65 years of age). The objective of this workshop was to discuss and develop consensus solutions to improve patient management and outcomes and to discuss what older adults should be told (and by whom) about postoperative brain health risks. Thus, the workshop was provider and patient oriented as well as solution focused rather than etiology focused. For those areas in which we determined that there were limited evidence-based recommendations, we identified knowledge gaps and the types of scientific knowledge and investigations needed to direct future best practice. Because concerns about perioperative neurocognitive injury in pediatric patients are already being addressed by the SmartTots initiative, our workshop discussion (and thus this article) focuses specifically on perioperative cognition in older adults. The 2 main perioperative cognitive disorders that have been studied to date are postoperative delirium and cognitive dysfunction. Postoperative delirium is a syndrome of fluctuating changes in attention and level of consciousness that occurs in 20%-40% of patients >60 years of age after major surgery and inpatient hospitalization. Many older surgical patients also develop postoperative cognitive deficits that typically last for weeks to months, thus referred to as postoperative cognitive dysfunction. Because of the heterogeneity of different tools and thresholds used to assess and define these disorders at varying points in time after anesthesia and surgery, a recent article has proposed a new recommended nomenclature for these perioperative neurocognitive disorders. Our discussion about this topic was organized around 4 key issues: preprocedure consent, preoperative cognitive assessment, intraoperative management, and postoperative follow-up. These 4 issues also form the structure of this document. Multiple viewpoints were presented by participants and discussed at this in-person meeting, and the overall group consensus from these discussions was then drafted by a smaller writing group (the 6 primary authors of this article) into this manuscript. Of course, further studies have appeared since the workshop, which the writing group has incorporated where appropriate. All participants from this in-person meeting then had the opportunity to review, edit, and approve this final manuscript; 1 participant did not approve the final manuscript and asked for his/her name to be removed.

Risk factors and outcome of postoperative delirium after transcatheter aortic valve replacement

BACKGROUND

POD is associated with a worse postoperative course in patients after cardiac surgery, but its incidence and effects after TAVR are not well-understood. The aim of the present study was to analyze incidence, risk factors, and in-hospital outcomes of postoperative delirium (POD) after transfemoral (TF-AVR) and transapical (TA-AVR) transcatheter aortic valve replacement (TAVR) in a nationwide cohort.

METHODS AND RESULTS

Administrative data on all patients undergoing isolated TAVR in Germany in 2014 were analyzed. 9038 TF-AVR and 2522 TA-AVR procedures were performed. POD incidence was 7% after TF-AVR and 12% after TA-AVR. Atrial fibrillation (TF: OR 1.35, p < 0.001; TA: OR 1.53, p = 0.001) and NYHA III/IV (TF: OR 1.23, p = 0.017, TA: OR 1.51, p = 0.001) were independent risk factors for POD. Dementia was a risk factor only in TF-AVR (OR 3.04, p < 0.001). Female sex was protective (TF: OR 0.56, p < 0.001, TA: OR 0.51, p < 0.001). We found the occurrence of POD to be associated with more postoperative complications such as stroke and bleeding. Consequently, patients with POD were ventilated and hospitalized longer and suffered an increased risk of in-hospital mortality (unadjusted OR TF: 1.83, p = 0.001, TA: 1.82, p = 0.01). After adjusting for postoperative events and comorbidities, POD's effect on in-hospital mortality disappeared. In contrast, stroke and bleeding remained independent predictors for mortality irrespective of POD.

CONCLUSIONS

Patients with POD after TAVR are at increased risk for in-hospital mortality. However, after adjusting for postoperative events and comorbidities, stroke and bleeding, but not POD, are independent mortality predictors.

Can we predict a delirium after cardiac surgery? A validation study of a delirium risk checklist

BACKGROUND

Delirium is a common temporary mental disorder that often occurs in patients who undergo cardiac surgery. It is important to prevent the negative side effects of delirium by identifying high-risk patients before surgery. Koster and colleagues designed a risk model to identify patients with an increased risk of postoperative delirium after cardiac surgery.

AIM

The aim of this study was to validate the risk model for delirium and further improve the risk model.

METHODS

A delirium risk checklist containing predictors associated with postoperative delirium was used during the preoperative outpatient screening in 329 patients. The delirium observation screening scale was used preoperatively and postoperatively to assess delirium.

RESULTS

Compared with the model of Koster and colleagues age greater than 70 years and a history of delirium were confirmed as statistically significant predictors of postoperative delirium, while cognitive impairment and alcohol abuse were almost significant factors. The European system for cardiac operative risk evaluation (EuroSCORE), comorbidity and type of surgery could not predict a postoperative delirium again. The area under the curve of this model was 0.79 (95% confidence interval (CI) 0.73-0.86; P<0.001). Based on the data of this study the model was improved with the following independent predictors of postoperative delirium: age, more than one comorbidity, history of delirium and a lower standardised mini mental state examination score as with an area under the curve of 0.79 (95% CI 0.73-0.85; P<0.001).

CONCLUSION

The risk model could not be fully validated. It is difficult to validate a risk model over time; there are different circumstances such as the increased focus on the prevention of delirium.

Risk factors for postoperative delirium after spine surgery in middle- and old-aged patients

BACKGROUND

Postoperative delirium is a common complication following various operative procedures with an incidence rate of 10-77 %.

AIM

To analyze various risk factors for postoperative delirium after spine surgery in the middle- and old-aged patients.

METHODS

This study retrospectively reviewed 451 patients (226 males and 225 females, an average age of 65.1 ± 18.3 years) who underwent spinal surgery in our hospital between January 2010 and August 2015. Patients who had features of acute onset and fluctuating course and any two of the other features were diagnosed with delirium. Cognitive tests consisting of Clinical Dementia Rating and Global Deterioration Scale were performed to evaluate delirium. T tests were used for statistical analysis of the difference between the two groups, and logistic regression analyses were used for determining the risk factors.

RESULTS

A total of 42 (9.3 %) patients were diagnosed with delirium. Delirious and non-delirious patients had no difference in age, gender, BMI, education level, drug treatment, comorbid disease history, surgical history, preoperative blood pressure, intraoperative blood loss, blood transfusion, use of surgical implants, surgical site, use of fentanyl and propofol, and preoperative VAS score. Intraoperative hypotension and use of dezocine were related to postoperative delirium (P = 0.03 and P = 0.07). The multiple regression equation was Y = -0.11 + 0.52 × X ₀ + 0.21 × X ₁, where X ₀ = amount of dezocine, X ₁ = instances of intraoperative hypotension.

CONCLUSION

Postoperative delirium commonly occurs after spine surgery. Intraoperative hypotension <80 mmHg and intraoperative use of dezocine represent valuable new predictors of the risk of delirium.

Delayed Recall and Working Memory MMSE Domains Predict Delirium following Cardiac Surgery

BACKGROUND

Reduced preoperative cognition is a risk factor for postoperative delirium. The significance for type of preoperative cognitive deficit, however, has yet to be explored and could provide important insights into mechanisms and prediction of delirium.

OBJECTIVE

Our goal was to determine if certain cognitive domains from the general cognitive screener, the Mini-Mental State Exam (MMSE), predict delirium after cardiac surgery.

METHODS

Patients completed a preoperative MMSE prior to undergoing elective cardiac surgery. Following surgery, delirium was assessed throughout ICU stay using the Confusion Assessment Method for ICU delirium and the Richmond Agitation and Sedation Scale.

RESULTS

Cardiac surgery patients who developed delirium (n = 137) had lower total MMSE scores than patients who did not develop delirium (n = 457). In particular, orientation to place, working memory, delayed recall, and language domain scores were lower. Of these, only the working memory and delayed recall domains predicted delirium in a regression model adjusting for history of chronic obstructive pulmonary disease, age, sex, and duration of cardiopulmonary bypass. For each word not recalled on the three-word delayed recall assessment, the odds of delirium increased by 50%. For each item missed on the working memory index, the odds of delirium increased by 36%. Of the patients who developed delirium, 47% had a primary impairment in memory, 21% in working memory, and 33% in both domains. The area under the receiver operating characteristics curve using only the working memory and delayed recall domains was 0.75, compared to 0.76 for total MMSE score.

CONCLUSION

Delirium risk is greater for individuals with reduced MMSE scores on the delayed recall and working memory domains. Research should address why patients with memory and executive vulnerabilities are more prone to postoperative delirium than those with other cognitive limitations.

Cognitive and functional status predictors of delirium and delirium severity after coronary artery bypass graft surgery: an interim analysis of the Neuropsychiatric Outcomes After Heart Surgery study

BACKGROUND

Cognitive and functional impairment increase risk for post-coronary artery bypass graft (CABG) surgery delirium (PCD), but how much impairment is necessary to increase PCD risk remains unclear.

METHODS

The Neuropsychiatric Outcomes After Heart Surgery (NOAHS) study is a prospective, observational cohort study of participants undergoing elective CABG surgery. Pre-operative cognitive and functional status based on Clinical Dementia Rating (CDR) scale and neuropsychological battery are assessed. We defined mild cognitive impairment (MCI) based on either (1) CDR global score 0.5 (CDR-MCI) or (2) performance 1.5 SD below population means on any cognitive domain on neurocognitive battery (MCI-NC). Delirium was assessed daily post-operative day 2 through discharge using the confusion assessment method (CAM) and delirium index (DI). We investigate whether MCI - either definition - predicts delirium or delirium severity.

RESULTS

So far we have assessed 102 participants (mean age 65.1 ± 9; male: 75%) for PCD. Twenty six participants (25%) have MCI-CDR; 38 (62% of those completing neurocognitive testing) met MCI-NC criteria. Fourteen participants (14%) developed PCD. After adjusting for age, sex, comorbidity, and education, MCI-CDR, MMSE, and Lawton IADL score predicted PCD on logistic regression (OR: 5.6, 0.6, and 1.5, respectively); MCI-NC did not (OR [95% CI]: 11.8 [0.9, 151.4]). Using similarly adjusted linear regression, MCI-CDR, MCI-NC, CDR sum of boxes, MMSE, and Lawton IADL score predicted delirium severity (adjusted R(2): 0.26, 0.13, 0.21, 0.18, and 0.32, respectively).

CONCLUSIONS

MCI predicts post-operative delirium and delirium severity, but MCI definition alters these relationships. Cognitive and functional impairment independently predict post-operative delirium and delirium severity.

The Association of Brain MRI Characteristics and Postoperative Delirium in Cardiac Surgery Patients

PURPOSE

Delirium is common after cardiac surgery and is associated with adverse consequences, including cognitive decline. Identification of vulnerable older adults might allow for early implementation of delirium-prevention strategies. Brain MRI findings provide insight into structural brain changes that may identify vulnerable patients. The purpose of this study was to examine the association between brain MRI characteristics potentially associated with delirium vulnerability and the development of postoperative delirium in a nested cohort of patients undergoing cardiac surgery.

METHODS

We identified 79 cardiac surgery patients who had brain MRI imaging after cardiac surgery, as part of an ongoing randomized trial evaluating the efficacy of blood pressure management based on cerebral autoregulation monitoring versus standard management for improving neurological outcomes. Cerebral lateral ventricular size, cortical sulcal width, and white matter hyperintensities (WMH) on brain MRI scans were graded on a validated 0 to 9 scale, and categorized into tertiles. New ischemic lesions were characterized as present or absent. Delirium was assessed using a validated chart-review. Neuropsychological testing performed before surgery was used to establish preoperative cognitive baseline. Multivariable logistic regression was used to assess the independent association between MRI characteristics and postoperative delirium.

FINDINGS

The average age of patients was 70.1 ± 7.8 years old, and 72% were male. Twenty-eight of 79 (35.4%) patients developed postoperative delirium. Patients with delirium had higher unadjusted ventricular size (median 4 vs. 3, P = 0.003), and there was a trend towards higher sulcal sizes and WMH grades. Increasing tertiles of ventricular size (Odds Ratio [OR] 3.59; 95% Confidence Interval [CI] 1.59-8.12; P = 0.002) and sulcal size (OR 2.15; 95%CI 1.13-4.12; P = 0.02) were associated with postoperative delirium, with a trend for tertiles of WMH grade (OR 1.91; 95%CI 0.99-3.68; P = 0.05). In multivariable models adjusted for logistic EuroSCORE, baseline cognitive status, bypass time, and any postoperative complication, each tertile of ventricular size was associated with increased odds of postoperative delirium (OR 3.23 per tertile increase in ventricular size; 95%CI 1.21-8.60; P = 0.02). There were no differences in odds of delirium by tertiles of sulcal grade, tertiles of white matter grade, or presence of new ischemic lesions, in adjusted models.

IMPLICATIONS

Increased brain ventricular size was independently associated with delirium after cardiac surgery. These results suggest that cerebral atrophy may contribute to increased vulnerability for postoperative delirium. Baseline brain MRIs may be useful in identifying cardiac surgery patients at high risk for postoperative delirium, who might benefit from targeted perioperative approaches to prevent delirium. ClinicalTrials.gov identifier: NCT00981474.

Preoperative Cognitive and Frailty Screening in the Geriatric Surgical Patient: A Narrative Review

PURPOSE

The identification of older patients who may have deficits in cognitive or functional domains will become more pressing as increasing numbers of these patients present for preoperative evaluations. The number of older adults with deficiencies in these areas is projected to grow, and more of these patients will present for assessment in preoperative clinics with the expectation that surgeries will be performed.

METHODS

We review current outcomes data for preoperative cognitive impairment and frailty.

FINDINGS

We point to a number of directions research is taking as systems for the prevention of postoperative cognitive and functional decline are being developed. We also discuss the current status of screening and examine potential instruments that can be used in the setting of the preanesthesia clinic.

IMPLICATIONS

Clinicians may anticipate that geriatric screening tools focused on cognitive and functional domains will play a direct role in the ongoing evolution of presurgical assessment and triage.

Depressive Symptoms Before, During, and After Delirium: A Literature Review

BACKGROUND

Delirium and depression are often thought of as mutually exclusive conditions. However, several studies cite depression as a risk factor for delirium whereas others note that patients with delirium often manifest depressive symptoms. Whether these depressive symptoms persist after delirium resolves remains unclear.

OBJECTIVES

This article reviews published studies that have investigated the relationship between depression and delirium.

METHODS

Literature searches on PubMed, CINAHL, Cochrane Library, and PsycInfo were conducted using search criteria "delirium" AND "depress⁎" as keywords or MeSH terms.

RESULTS

Of 722 search results, 10 prospective cohort studies were identified for inclusion. These studies were categorized regarding the time of assessment for depressive symptoms. Included studies varied greatly (regarding their index population, their methods of assessment, and their timing of assessments). Of the studies, 3 involved patients undergoing hip fracture repair. They demonstrated more severe depressive symptoms both during delirium and after delirium ended. Conversely, the other studies did not find any statistically significant correlations between the 2 conditions.

CONCLUSIONS

The literature suggests a correlation between depression and delirium in patients with hip fracture. Whether other specific populations have higher comorbidity is unclear. Unfortunately, studies varied widely in their methods, precluding a meta-analysis. Nonetheless, our review provides a foundation for future research.

Risk factors associated with postoperative delirium after surgery for oral cancer

OBJECTIVE

The purpose of this study was to retrospectively investigate the multivariate relationships among the various risk factors for postoperative delirium in patients undergoing oral cancer surgery.

MATERIAL AND METHODS

The medical records of all patients with oral cancer who underwent curative head and neck surgery between April 2011 and March 2013 at our institution were retrospectively reviewed. There was a total of 188 patients, including 110 males and 78 females.

RESULTS

We found that older age, extensive surgical procedure, longer operation, excessive hemorrhage, blood transfusion, longer postoperative management in the intensive care unit, longer postoperative hospital stay, lower albumin level in the preoperative blood test, and lower total protein, albumi, n and hemoglobin levels and a higher C-reactive protein (CRP) level in the postoperative blood tests were significant variables in the univariate analysis (p < 0.05). We also determined that an older age (odds ratio [OR] = 6.83), intraoperative lower hemoglobin levels (OR = 6.82), and excessive hemorrhage (OR = 3.62) during surgery were significant variables in the multivariate analysis.

CONCLUSION

Clinicians should pay special attention to preventing delirium during the postoperative management of older patients with these risk factors. Furthermore, increasing the hemoglobin levels during surgery may be able to prevent postoperative delirium.

Mild cognitive impairment with associated inflammatory and cortisol alterations as independent risk factor for postoperative delirium

AIMS

The present study aimed to determine the impact of mild cognitive impairment (MCI) on the development of postoperative delirium and, secondly, to assess the association between MCI and raised perioperative cortisol, cytokine, cobalamin and homocysteine levels.

METHODS

The study recruited 113 consecutive adult patients scheduled for cardiac surgery with cardiopulmonary bypass. The patients were examined preoperatively with the Montreal Cognitive Assessment and Trail Making Test. A diagnosis of MCI was established based upon the criteria of the National Institute on Aging and Alzheimer's Association. Patients were screened for delirium within the first 5 days postoperatively.

RESULTS

MCI was diagnosed in 24.8% of the patients, whereas the frequency of delirium was 36%. A multivariate analysis demonstrated that individuals with MCI were at a significantly higher risk of postoperative delirium (OR = 6.33, p = 0.002). Preoperative cortisol, postoperative cortisol and IL-2 plasma levels were higher in the MCI group as compared to non-MCI subjects.

CONCLUSION

MCI is associated with a higher risk of postoperative delirium. Perioperative cortisol and inflammatory alterations observed in MCI may provide a physiological explanation for this increased risk.

The assessment of the T102C polymorphism of the 5HT2a receptor gene, 3723G/A polymorphism of the NMDA receptor 3A subunit gene (GRIN3A) and 421C/A polymorphism of the NMDA receptor 2B subunit gene (GRIN2B) among cardiac surgery patients with and without delirium

OBJECTIVE

The studies regarding the role of genes polymorphism in development of postoperative delirium are extremely rare. Therefore, we investigated the potential association of polymorphism in 5HT2a receptor gene and N-methyl-d-aspartate (NMDA) receptor 3A and 2B subunits genes with postoperative delirium.

METHOD

We conducted a prospective, nested, case-control study. For analysis, 3723 G/A (rs3739722) polymorphism in the GRIN3A gene, 421 C/A (rs3764028) polymorphism in the GRIN2B gene and T102C (rs6313) polymorphism in the 5HT2A gene were selected.

RESULTS

Genetic analysis confirmed that there were significant differences in genotype frequencies for 3723 G/A between delirium patients and controls. No other significant associations were observed. Moreover, according to the multivariate conditional logistic regression analysis the presence of AG haplotype of GRIN3A gene was independently associated with postoperative delirium.

CONCLUSIONS

These findings suggest that the genetic variations of NR3A subunit of NMDA receptor may be a predisposing factor to delirium among the Polish population of cardiac surgery patients.

Delirium and depression: inter-relationship and clinical overlap in elderly people

Delirium and depression are complex neuropsychiatric syndromes common in the elderly and are associated with poor health-care outcomes. Accurate diagnosis is essential to the provision of optimum health care for individuals with these conditions but is complicated by substantial clinical overlap in symptoms and comorbidities. A careful assessment of the patient's symptoms, including their context and time course, is needed for accurate diagnosis. Previous depression is common in patients with delirium and depressive illness is a recognised sequelae of delirium. The two syndromes seem to be caused by similar pathophysiological mechanisms, involving disturbances in stress and inflammatory responses, monoaminergic and melatonergic signalling, which point to new avenues for therapeutic intervention. Improved methods to assess delirium and depression in populations at high risk by virtue of their age, diminished cognitive reserve and physical frailty is a key target to achieve improved health-care outcomes in elderly individuals.

Preexisting cognitive status is associated with reduced behavioral functional capacity in patients 3 months after cardiac surgery: an extension study

OBJECTIVE

To examine whether preexisting cognitive status rather than short- and middle-term postoperative cognitive decline (POCD) may differentially account for behavioral functional capacity 3 months after cardiac surgery.

METHOD

Seventy-nine patients completed a psychological evaluation, including the Trail Making Test Part B, the memory with 10-s interference, the phonemic fluency and the Instrumental Activities of Daily Living (IADLs) questionnaire for cognitive functions and behavioral functional capacity, respectively, before surgery, at discharge and at 3-month follow-up.

RESULTS

Thirty-one (39%) and 22 (28%) patients showed POCD at discharge and at 3-month follow-up, respectively. Preoperative cognitive status was significantly associated with change in behavioral functional capacity 3 months after surgery (Ps<.003), whereas short- and middle-term POCD and intraoperative risk factors were unrelated to residualized change in IADLs scores (all Ps>.095).

CONCLUSIONS

Preexisting cognitive deficit, especially working memory deficit, rather than short- and middle-term POCD related to intraoperative risk factors is associated with poor behavioral functional capacity 3 months after cardiac surgery. The present study therefore suggests that a preoperative cognitive evaluation is essential to anticipate which patients are likely to show a decline in behavioral functional capacity after cardiac surgery.

Dexmedetomidine: a review of applications for cardiac surgery during perioperative period

Cardiac surgery is associated with a high incidence of cardiovascular and other complications during the perioperative period that translate into increased mortality and prolonged hospital stays. Safe comprehensive perioperative management is required to eliminate these adverse events. Dexmedetomidine is a selective α2-adrenoreceptor agonist that has been described as an ideal medication in the perioperative period of cardiac surgery. The major clinical effects of dexmedetomidine in this perioperative period can be summarized as attenuating the hemodynamic response, cardioprotective effects, antiarrhythmic effects, sedation in the ICU setting, treatment of delirium, and procedural sedation. Although there are some side effects of dexmedetomidine, it is emerging as an effective therapeutic agent in the management of a wide range of clinical conditions with an efficacious, safe profile. The present review serves as an overview update in the diverse applications of dexmedetomidine for cardiac surgery during the perioperative period.

Dexmedetomidine: a review of applications for cardiac surgery during perioperative period

Cardiac surgery is associated with a high incidence of cardiovascular and other complications during the perioperative period that translate into increased mortality and prolonged hospital stays. Safe comprehensive perioperative management is required to eliminate these adverse events. Dexmedetomidine is a selective α2-adrenoreceptor agonist that has been described as an ideal medication in the perioperative period of cardiac surgery. The major clinical effects of dexmedetomidine in this perioperative period can be summarized as attenuating the hemodynamic response, cardioprotective effects, antiarrhythmic effects, sedation in the ICU setting, treatment of delirium, and procedural sedation. Although there are some side effects of dexmedetomidine, it is emerging as an effective therapeutic agent in the management of a wide range of clinical conditions with an efficacious, safe profile. The present review serves as an overview update in the diverse applications of dexmedetomidine for cardiac surgery during the perioperative period.

Raised IL-2 and TNF-α concentrations are associated with postoperative delirium in patients undergoing coronary-artery bypass graft surgery

BACKGROUND

The knowledge base regarding the pathogenesis of postoperative delirium is limited. The primary aim of this study is to investigate whether increased levels of IL-2 and TNF-α are associated with delirium in patients who underwent coronary-artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB). The secondary aim is to establish whether any association between raised cytokine levels and delirium is related to surgical and anesthetic procedures or mediated by pre-existing conditions associated with raised cytokine levels, such as major depressive disorder (MDD), cognitive impairment, or aging.

METHODS

Patients were examined and screened for MDD and cognitive impairment one day preoperatively, using the Mini International Neuropsychiatric Interview and The Montreal Cognitive Assessment and Trail Making Test Part B. Blood samples were collected postoperatively for cytokine levels.

RESULTS

Postoperative delirium screening was found positive in 36% (41 of 113) of patients. A multivariate logistic regression revealed that an increased concentration of pro-inflammatory cytokines is associated with delirium, and related to advancing age, preoperative cognitive decline of participants, and duration of CPB. According to receiver operating characteristic analysis, the most optimal cut-off for IL-2 and TNF-α concentrations in predicting the development of delirium were 907.5 U/ml and 10.95 pg/ml, respectively.

CONCLUSIONS

The present study suggests that raised postoperative cytokine concentrations are associated with delirium after CABG surgery. Postoperative monitoring of pro-inflammatory markers combined with regular surveillance may be helpful in the early detection of postoperative delirium in this patient group.

Predicting functional decline in older patients undergoing cardiac surgery

BACKGROUND

a growing number of older patients undergo cardiac surgery. Some of these patients are at increased risk of post-operative functional decline, potentially leading to reduced quality of life and autonomy, and other negative health outcomes. First step in prevention is to identify patients at risk of functional decline. There are no current published tools available to predict functional decline following cardiac surgery.

OBJECTIVE

to validate the identification of seniors at risk-hospitalised patients (ISAR-HP), in older patients undergoing cardiac surgery.

DESIGN AND METHODS

a multicenter cohort study in cardiac surgery wards of two university hospitals with follow-up 3 months after hospital admission.

INCLUSION CRITERIA

consecutive cardiac surgery patients, aged ≥65. Functional decline was defined as a decline of at least one point on the Katz ADL Index at follow-up compared with preadmission status.

RESULTS

475 patients were included, 16% of all patients and 20% of patients ≥70+ suffered functional decline. The amended prediction model predicted functional decline using four criteria: preadmission need for daily assistance in instrumental activities of daily living, use of a walking device, need for assistance in travelling and no education after age 14. Area under the receiver operating curve for patients ≥70 it was 0.73. For the amended ISAR-HP sensitivity, specificity, positive and negative predictive values were 85, 48, 29 and 93%, respectively.

CONCLUSIONS

the amended ISAR-HP used in older cardiac surgery patients showed good discriminative values at score ≥1, supporting the generalisability of this prediction model for this patient group.

Delirium in patients admitted to a cardiac intensive care unit with cardiac emergencies in a developing country: incidence, prevalence, risk factor and outcome

AIM

To assess the incidence, prevalence, risk factors and outcome of delirium in patients admitted to a cardiac intensive care unit (ICU) of a tertiary care hospital.

METHODS

Three hundred nine consecutive patients admitted to a 22-bed coronary care unit were screened for presence of delirium by using Confusion Assessment Method for Intensive Care Unit (CAM-ICU), and those found positive on CAM-ICU were further evaluated by a psychiatrist to confirm the diagnosis of delirium as per DSM-IV-TR criteria. Patients were also evaluated for the risk factors for delirium and outcome of delirium.

RESULTS

Incidence rate of delirium was 9.27%, and prevalence rate was 18.77%. The risk factors identified for delirium in binary logistic regression analysis were hypokalemia, Sequential Organ Failure Assessment score, presence of cognitive deficits, receiving more than three medications, sepsis, hyponatremia, presence of cardiogenic shock, having undergone coronary artery bypass grafting, left ventricular ejection fraction <30, currently receiving opioids, age more than 65 years, presence of diabetes mellitus, presence of uncontrolled diabetes mellitus, history of seizures, presence of congestive cardiac failure, having undergone angioplasty, presence of atrial fibrillation, ongoing depression, currently receiving/taking benzodiazepines, warfarin, ranitidine, steroids, non-steroidal anti-inflammatory drugs, higher total number of medications, presence of raised creatinine, anaemia, hypoglycemia, Acute Physiology and Chronic Health Evaluation II score and Charlson Comorbidity Index score. About one fourth (n=22; 27%) of the patients who developed delirium died during the hospital stay in contrast to 1% mortality in the non-delirious group. Those with delirium also had longer stay in the ICU.

CONCLUSIONS

Delirium is highly prevalent in the cardiac ICU setting and is associated with presence of many modifiable risk factors. Development of delirium increases the mortality risk and is associated with longer cardiac ICU stay.

Prevalence and risk factors of postoperative delirium in patients undergoing open heart surgery in northwest of iran

INTRODUCTION

Delirium as a relatively common complication following cardiac surgery remains a contributory factor in postoperative mortality and an obstacle to early discharge of patients.

METHODS

In the present study 329 patients who underwent open heart surgery between 1st January 2008 to 1st January 2009 in Shahid Madani Heart Center, Tabriz, Iran were enrolled.

RESULTS

Overall 4.9% of patients developed delirium after cardiac surgery. We found atrial fibrillation (P = 0.005), lung diseases (P = 0.04) and hypertension (P = 0.02) to be more common in patients who develop delirium postoperatively. Furthermore, the length of intensive care unit (ICU) stay, cardiopulmonary bypass (CPB) time, and ventilation period were also significantly increased. Also a statistically meaningful relationship between the female gender and development of delirium was also noted (P = 0.02). On the other hand no meaningful relationship was detected between diabetes, history of cerebral vascular diseases, peripheral vascular diseases, myocardial infarction, development of pneumonia following surgery, and laboratory levels of sodium, potassium, glucose, and complete blood cell count (CBC) including white blood cells, red blood cells, platelets in the blood-hemoglobin and hematocrits. Also environmental factors like presence of other patients or companion with the patient, and objects like clock, window and calendar in the patient's room did not affect prevention of delirium.

CONCLUSION

Based on this and other investigations, it can be suggested to use MMPI test to recognize pathologic elements to prevented delirium after surgery and complementary treatment for coping with delirium.

Preexisting depressive symptoms are associated with long-term cognitive decline in patients after cardiac surgery

OBJECTIVE

To examine whether preoperative psychological dysfunctions rather than intraoperative factors may differentially predict short- and long-term postoperative cognitive decline (POCD) in patients after cardiac surgery.

METHOD

Forty-two patients completed a psychological evaluation, including the Trail Making Test Part A and B (TMT-A/B), the memory with 10/30-s interference, the phonemic verbal fluency and the Center for Epidemiological Studies of Depression (CES-D) scale for cognitive functions and depressive symptoms, respectively, before surgery, at discharge and at 18-month follow-up.

RESULTS

Ten (24%) and 11 (26%) patients showed POCD at discharge and at 18-month follow-up, respectively. The duration of cardiopulmonary bypass significantly predicted short-term POCD [odds ratio (OR)=1.04, P<.05], whereas preoperative psychological factors were unrelated to cognitive decline at discharge. Conversely, long-term cognitive decline after cardiac surgery was significantly predicted by preoperative scores in the CES-D (OR=1.26, P<.03) but not by intraoperative variables (all Ps >.23).

CONCLUSIONS

Our findings showed that preexisting depressive symptoms rather than perioperative risk factors are associated with cognitive decline 18 months after cardiac surgery. This study suggests that a preoperative psychological evaluation of depressive symptoms is essential to anticipate which patients are likely to show long-term cognitive decline after cardiac surgery.

Treatment of delirium following cardiac surgery

Postoperative delirium is a common medical complication following cardiac surgery. This paper will outline the treatment options for delirium with a focus on prophylactic use of risperidone before cardiac surgery.

Cortisol levels and neuropsychiatric diagnosis as markers of postoperative delirium: a prospective cohort study

Introduction

The pathophysiology of delirium after cardiac surgery is largely unknown. The purpose of this study was to investigate whether increased concentration of preoperative and postoperative plasma cortisol predicts the development of delirium after coronary artery bypass graft surgery. A second aim was to assess whether the association between cortisol and delirium is stress related or mediated by other pathologies, such as major depressive disorder (MDD) or cognitive impairment.

Methods

The patients were examined 1 day preoperatively with the Mini International Neuropsychiatric Interview and the Montreal Cognitive Assessment and the Trail Making Test to screen for depression and for cognitive impairment, respectively. Blood samples for cortisol levels were collected both preoperatively and postoperatively. The Confusion Assessment Method for the Intensive Care Unit was used within the first 5 days postoperatively to screen for a diagnosis of delirium.

Results

Postoperative delirium developed in 36% (41 of 113) of participants. Multivariate logistic regression analysis revealed two groups independently associated with an increased risk of developing delirium: those with preoperatively raised cortisol levels; and those with a preoperative diagnosis of MDD associated with raised levels of cortisol postoperatively. According to receiver operating characteristic analysis, the most optimal cutoff values of the preoperative and postoperative cortisol concentration that predict the development of delirium were 353.55 nmol/l and 994.10 nmol/l, respectively.

Conclusion

Raised perioperative plasma cortisol concentrations are associated with delirium after coronary artery bypass graft surgery. This may be an important pathophysiological consideration in the increased risk of postoperative delirium seen in patients with a preoperative diagnosis of MDD.

Meta-analysis of factors which influence delirium following cardiac surgery

BACKGROUND

The aim of this study is to determine the risk factors of delirium after cardiac surgery.

METHODS

A systematic literature search of MEDLINE, EMBASE, the Cochrane Library, and Science Citation Index limited to 2008 to 2011 and review of studies was conducted. Eligible studies were of randomized controlled trials or cohort studies, using delirium assessment tool, reporting at least one risk factor associated with delirium, and available to full text.

RESULTS

The search identified 106 potentially relevant publications; only 25 met selection criteria. Our systematic review revealed 33 risk factors: 17 predisposing and 16 precipitating factors for delirium after elective cardiac surgery. The most established predisposing risk factors were age, depression, and history of stroke, cognitive impairment, diabetes mellitus, and atrial fibrillation. The most established precipitating risk factors were duration of surgery, prolonged intubation, surgery type, red blood cell transfusion, elevation of inflammatory markers and plasma cortisol level, and postoperative complications. Moreover, sedation with dexmedetomidine may significantly predict the absence of postoperative delirium.

CONCLUSIONS

Postoperative delirium is related to several risk factors following cardiac surgery. Sedation with dexmedetomidine and fast-track weaning protocols may decrease the incidence of delirium in cardiac surgical patients.

Pharmacological risk factors for delirium after cardiac surgery: a review

PURPOSE

The objective of this review is to evaluate the literature on medications associated with delirium after cardiac surgery and potential prophylactic agents for preventing it.

SOURCE

Articles were searched in MEDLINE, Cumulative Index to Nursing and Allied Health, and EMBASE with the MeSH headings: delirium, cardiac surgical procedures, and risk factors, and the keywords: delirium, cardiac surgery, risk factors, and drugs. Principle inclusion criteria include having patient samples receiving cardiac procedures on cardiopulmonary bypass, and using DSM-IV-TR criteria or a standardized tool for the diagnosis of delirium.

PRINCIPAL FINDINGS

Fifteen studies were reviewed. Two single drugs (intraoperative fentanyl and ketamine), and two classes of drugs (preoperative antipsychotics and postoperative inotropes) were identified in the literature as being independently associated with delirium after cardiac surgery. Another seven classes of drugs (preoperative antihypertensives, anticholinergics, antidepressants, benzodiazepines, opioids, and statins, and postoperative opioids) and three single drugs (intraoperative diazepam, and postoperative dexmedetomidine and rivastigmine) have mixed findings. One drug (risperidone) has been shown to prevent delirium when taken immediately upon awakening from cardiac surgery. None of these findings was replicated in the studies reviewed.

CONCLUSION

These studies have shown that drugs taken perioperatively by cardiac surgery patients need to be considered in delirium risk management strategies. While medications with direct neurological actions are clearly important, this review has shown that specific cardiovascular drugs may also require attention. Future studies that are methodologically consistent are required to further validate these findings and improve their utility.

Depression, anxiety, and cardiac morbidity outcomes after coronary artery bypass surgery: a contemporary and practical review

Research to date indicates that the number of coronary artery bypass graft (CABG) surgery patients affected by depression (i.e., major, minor, dysthymia) approximates between 30% and 40% of all cases. A longstanding empirical interest on psychosocial factors in CABG surgery patients highlights an association with increased risk of morbidity in the short and longer term. Recent evidence suggests that both depression and anxiety increase the risk for mortality and morbidity after CABG surgery independent of medical factors, although the behavioral and biological mechanisms are poorly understood. Though neither depression nor anxiety seem to markedly affect neuropsychological dysfunction, depression confers a risk for incident delirium. Following a comprehensive overview of recent literature, practical advice is described for clinicians taking into consideration possible screening aids to improve recognition of anxiety and depression among CABG surgery patients. An overview of contemporary interventions and randomized, controlled trials are described, along with suggestions for future CABG surgery research.

Factors related to postoperative delirium in patients with lower limb ischaemia: a prospective cohort study

OBJECTIVES

To preoperatively determine candidates at definitive risk of postoperative delirium (POD), we identified relevant factors in patients with arteriosclerosis obliterans who underwent bypass surgery.

DESIGN

A prospective cohort study.

PATIENTS AND METHODS

299 patients (age ≥ 60 years) who underwent bypasses in 1995-2006 were enrolled. Cognitive impairment was assessed by the Revised Hasegawa Dementia Scale, the Confusion Assessment Method was also used, and severity was graded as Grade I-III (mild to severe) based on the Delirium Rating Scale. All patients were followed for 3 years.

RESULTS

POD occurred in 88 patients (29%), with a median age of 75 (10) years (IQR). Onset was 2 (1) days postoperatively, and a duration of 2 (2) days was observed. POD was hyperactive in 89% and was Grade I, II, and III in 11%, 68%, and 21% respectively. Multiple logistic regression analysis identified the following risk factors for POD: age ≥ 72 years (<0.0001), end-stage renal failure (0.001), multiple occlusive lesions (<0.0001), cognitive impairment (0.003), and critical limb ischaemia (0.034). The 3-year survival rate was similar when comparing POD and non-POD patients (84% vs. 88%, NS).

CONCLUSIONS

This study identified 5 risk factors for POD in patients undergoing bypasses for limb ischaemia. Long-term outcomes were similar when comparing the patients who experienced POD with those who did not.

Preoperative statin therapy is not associated with a decrease in the incidence of delirium after cardiac operations

BACKGROUND

Delirium after cardiac operations is associated with significant morbidity and death. Statins have been recently suggested to exert protective cerebral effects. This study investigated whether preoperative statins were associated with decreased incidence of postoperative delirium in patients undergoing coronary artery bypass grafting.

METHODS

The study enrolled 4,659 consecutive patients (21% women; age, 67.8±9.2 years) undergoing coronary artery bypass grafting. A propensity score-based optimal-matching algorithm was used to match 1,577 patients receiving preoperative statins with a control group (1:1). Patients were screened for delirium in the intensive care unit according to the Confusion Assessment Method for the intensive care unit.

RESULTS

Delirium affected 89 patients (3%), and preoperative statin administration was not multivariably associated with a decreased incidence of delirium (odds ratio, 1.52; 95% confidence interval, 0.97 to 2.37; p=0.18) and was also unrelated to a delirium decrease in patient subgroups undergoing isolated coronary artery bypass grafting (odds ratio, 1.31; 95% confidence interval, 0.68 to 2.52; p=0.51) or combined valvular procedures (odds ratio, 1.72; 95% confidence interval, 0.96 to 3.07, p=0.08). Similar results were observed for age groups and cardiopulmonary bypass durations. Patients affected by postoperative delirium experienced a longer hospital stay (25th to 75th percentile) of 11 (7 to 18 days) vs 7 days (7 to 8 days, p<0.001) and 12% hospital mortality vs 1% (p<0.001).

CONCLUSIONS

Preoperative statins were not associated with a decreased incidence of delirium in patients undergoing coronary revascularization.

Predictors of Prolonged Stay in the Intensive Care Unit following Cardiac Surgery

The prediction of intensive care unit length of stay (ICU-LOS) could contribute to more efficient ICU resources' allocation and better planning of care among cardiac surgery patients. The aim of this study was to identify the preoperative and intraoperative predictors for prolonged cardiac surgery ICU-LOS. An observational cohort study was conducted among 150 consecutive patients, who were admitted to the cardiac surgery ICU of a tertiary hospital of Athens, Greece from September 2010 to January 2011. Multivariate regression analysis revealed that patients with increased creatinine levels preoperatively (odds ratio (OR) 3.0, P = 0.049), history of atrial fibrillation (AF) (OR 6.3, P = 0.012) and high EuroSCORE values (OR 2.6, P = 0.017) had a significant greater probability to stay in the ICU for more than 2 days. In addition, intraoperative hyperglycemia (OR 3.0, P = 0.004) was strongly associated with longer ICU-LOS. In conclusion, the high perioperative risk, the history of AF and renal dysfunction, and the intraoperative hyperglycemia are significant predictors of prolonged ICU stay. The early identification of patients at risk could allow the efficient ICU resources' allocation and the reduction of healthcare costs. This would contribute to nursing care planning depending on the availability of healthcare personnel and ICU bed capacity.

A brief review of practical preoperative cognitive screening tools

PURPOSE

Preoperative cognitive impairment is associated with the development of postoperative delirium, a common and consequential complication of major surgery in older patients. Screening for cognitive impairment should become a routine part of the preoperative evaluation of older patients; however, its implementation is hampered by limited clinical time and resources. The objective of this review was to identify cognitive screening tools that could be easily incorporated into the evaluation of older patients before major surgery.

SEARCH STRATEGY

Using strict inclusion and exclusion criteria, we searched PubMed over a 15-year period for short and simple cognitive screening tools. In addition, we reviewed studies that examined these cognitive screening tools in a perioperative environment. SEARCH RESULTS: We identified six cognitive screening tools that could each be administered in 2.5 min or less. Among the tools, sensitivity for cognitive impairment ranged from 79-99%, while specificity ranged from 70-98%. Only one (Mini-Cog) of the six tools we identified had been tested in a perioperative environment.

CONCLUSIONS

Incorporating a cognitive screening assessment into the preoperative evaluation of older patients is feasible. More research is needed to validate cognitive screening tools in the perioperative setting.

Early post-cardiac surgery delirium risk factors

The purpose of this study was to identify the post-cardiac surgery delirium risk factors and to evaluate clinical outcomes. Data on 90 patients with postoperative delirium after cardiac surgery on cardiopulmonary bypass (CPB) were analyzed retrospectively. The patients were divided into two groups by evaluating the severity of the delirium: light and moderate delirium group (n=74) and severe delirium group (n=16). We found that the rate of early post-cardiac surgery delirium was low (4.17%). We have determined that post-cardiac surgery delirium prolonged the length of stay in the Intensive Care Unit (ICU) by (8.4 (8.6)) and the hospital stay by (23.6 (13.0)) days. The patients had higher preoperative risk scores, their age was 71.5 (8.9) years, the body mass index was 28.8 (4.4) kg/m(2), the majority were male (72.2%), and the left ventricular ejection fraction was 46.1(11.9) %. Statistical analysis by multivariable logistic regression has indicated that increasing the dose of fentanyl administered during surgery over 1.4 mg also increased the possibility of developing a severe delirium (OR=29.4, CI 4.1-210.3) and longer aortic clamping time could be independently associated with severe postoperative delirium (OR=8.0, CI 1.7-37.2). After surgery, new atrial fibrillation (AF) episodes amounted to 53.3% and, after distinguishing the delirium severity groups, AF developed in the patients belonging to the severe delirium groups statistically significantly more frequently, 81.8 vs 47.3, where p=0.01. Our data suggest that early post-cardiac surgery delirium is not a common complication, but it prolonged the length of stay at the ICU and in the hospital. The delirium risk factors, such as longer aortic clamping time, the dose of fentanyl and new atrial fibrillation episodes occurring after cardiac surgery, are associated statistically significantly with the development of severe post-cardiac surgery delirium.