Predictors and outcomes of delirium

Evaluating Nutritional Risk Factors for Delirium in Intensive-Care-Unit Patients: Present Insights and Prospects for Future Research

Malnutrition, hypercatabolism, and metabolic changes are well-established risk factors for delirium in critically ill patients. Although the exact mechanisms are not fully understood, there is mounting evidence suggesting that malnutrition can cause a variety of changes that contribute to delirium, such as electrolyte imbalances, immune dysfunction, and alterations in drug metabolism. Therefore, a comprehensive metabolic and malnutrition assessment, along with appropriate nutritional support, may help to prevent or ameliorate malnutrition, reduce hypercatabolism, and improve overall physiological function, ultimately lowering the risk of delirium. For this aim, bioelectrical impedance analysis can represent a valuable strategy. Further research into the underlying mechanisms and nutritional risk factors for delirium is crucial to developing more effective prevention strategies. Understanding these processes will allow clinicians to personalize treatment plans for individual patients, leading to improved outcomes and quality of life in the intensive-care-unit survivors.

Clinical practice guideline recommendations for diagnosis and management of anxiety and depression in hospitalized adults with delirium: a systematic review

BACKGROUND

Delirium commonly occurs in hospitalized adults. Psychiatric disorders such as anxiety, depression, and post-traumatic stress disorder (PTSD) can co-occur with delirium, and can be recognized and managed by clinicians using recommendations found in methodological guiding statements called Clinical Practice Guidelines (CPGs). The specific aims of this review were to: [1] synthesize CPG recommendations for the diagnosis and management of anxiety, depression, and PTSD in adults with delirium in acute care; and [2] identify recent published literature in addition to those identified and reported in a 2017 review on delirium CPG recommendations and quality.

METHODS

MEDLINE, EMBASE, CINAHL, PsycINFO, and 21 sites on the Canadian Agency for Drugs and Technologies listed in the Health Grey Matters Lite tool were searched from inception to February 12, 2021. Selected CPGs focused on delirium in acute care, were endorsed by an international scientific society or governmental organization, and contained at least one recommendation for the diagnosis or management of delirium. Two reviewers independently extracted data in duplicate and independently assessed CPG quality using the AGREE-II tool. Narrative synthesis of CPG recommendations was conducted.

RESULTS

Title and abstract screening was completed on 7611 records. Full-text review was performed on 197 CPGs. The final review included 27 CPGs of which 7 (26%) provided recommendations for anxiety (4/7, 57%), depression (5/7, 71%), and PTSD (1/7, 14%) in delirium. Twenty CPGs provided recommendations for delirium only (e.g., assess patient regularly, avoid use of benzodiazepines). Recommendations for the diagnosis of psychiatric disorders with delirium included using evidence-based diagnostic criteria and standardized screening tools. Recommendations for the management of psychiatric disorders with delirium included pharmacological (e.g., anxiolytics, antidepressants) and non-pharmacological interventions (e.g., promoting patient orientation using clocks). Guideline quality varied: the lowest was Applicability (mean = 36%); the highest Clarity of Presentation (mean = 76%).

CONCLUSIONS

There are few available evidence-based CPGs to facilitate appropriate diagnosis and management of anxiety, depression, and PTSD in patients with delirium in acute care. Future guideline developers should incorporate evidence-based recommendations on the diagnosis and management of these psychiatric disorders in delirium.

SYSTEMATIC REVIEW REGISTRATION

Registration number: PROSPERO (CRD42021237056).

The Assessment of Immediate Postoperative Delirium in Neurologically Intact Adult Patients Admitted to the Post-anesthesia Care Unit: A Cross-Sectional Study

Background

Immediate postoperative delirium (IPD) in the post-anesthesia care unit (PACU) can cause significant morbidity affecting everyday activities and length of stay with cost implications. This study was undertaken to find the proportion of IPD in PACU and its association with anesthesia and other perioperative factors.

Methods

After obtaining ethical approval and informed consent, this cross-sectional study was conducted in the PACU. A total of 600 consecutive adult patients (American Society of Anesthesiologists (ASA) 1-3) posted for surgery were approached between January and March 2019, of which 402 patients without neurological diseases and language and hearing discrepancies were studied. All patients had the intervention of surgery under anesthesia in a usual manner. Delirium was assessed preoperatively, postoperatively at 15 and 30 minutes, and before discharge from the PACU. IPD was assessed using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) score, while sedation/agitation was assessed using the Richmond Agitation-Sedation Scale (RASS). The primary outcomes were the proportion of IPD, association with anesthesia, and perioperative risk factors. The secondary outcomes were the length of stay, delirium treatment, and mortality.

Results

Overall, the IPD proportion was 14.7%. A significant association was demonstrated with premedication with midazolam (odds ration (OR): 3.2; 95% confidence interval (CI): 1.42-7.35; P=0.003), general anesthesia (GA) (OR: 6.3; 95% CI: 2.23-17.8; P<0.001), duration of anesthesia (126 versus 95 minutes; P=0.001), laparoscopic mode of surgical access (OR: 3.4; 95% CI: 1.8-6.4; P<0.001), and postoperative RASS >/< 0 (OR: 10.6; 95% CI: 4.69-24.11; P<0.001) at 30 minutes and before discharge from the PACU. Multivariate analysis showed the strongest association of RASS at 30 minutes with IPD.

Conclusion

The proportion of IPD was found to be 14.7% in this study, and the chances of developing IPD are high if the patient is not awake and calm in the PACU, especially if midazolam is administered as premedication, followed by general anesthesia (GA) for a long duration.

Hospitalizations of older people in an emergency department related to potential medication-induced hyperactive delirium: a cross-sectional study

Background Although delirium is one of the most common adverse drug reactions observed in hospitalized older people, it remains underdiagnosed. Aim To estimate the prevalence of hospitalization of older people with potential medication-induced hyperactive delirium in the emergency department (ED); to identify the risk factors and the medicines frequently associated with the occurrence of the syndrome. Method A cross-sectional, retrospective study was performed with older people (age ≥ 60) admitted in 2018 to a Brazilian ED. The hospitalizations with suspected hyperactive delirium were screened with the aid of trigger-tools: International Code of Diseases-10th Revision, intra-hospital prescriptions of antipsychotics, and trigger-words related to the syndrome. A chart-review and medication review were developed to establish the causality assessment between adverse event and medicine. Logistic regression was used to determine risk factors for occurrence. Results Among the hospitalizations included, 67.5% (193/286) were screened by at least one trigger-tool. Of these, potential medication-induced hyperactive delirium was observed in 26.0% (50/193). The prevalence estimated in the ward was 17.5% (50/286). Opioids (31.9%), benzodiazepines (18.8%) and corticosteroids (10.6%) were the commonest medicines associated with delirium. Long-lived patients (p = 0.005), potentially inappropriate medicines (PIMs) (p = 0.025), and high weighted deliriogenic load (p = 0.014) were associated with potential medication-induced hyperactive delirium. Conclusion Approximately one in six hospitalizations of older people in the ED showed potential medication-induced hyperactive delirium. Data suggest PIMs and high weighted deliriogenic load, rather than polypharmacy or anticholinergic burden, are considered the most important characteristics of pharmacotherapy associated with avoidable hyperactive delirium among long-lived patients.

Risk Factors for Delirium after Vascular Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Vascular surgery is considered a risk factor for the development of postoperative delirium (POD). In this systematic review we provide a report on the incidence and risk-factors of POD after vascular surgery.

METHODS

A systematic literature search was conducted using Pubmed with the MeSH terms and key words "delirium" or "confusion", "vascular surgery procedures" and "risk factors or "risk assessment". Studies were selected for review after meeting the following inclusion criteria: vascular surgery, POD diagnosed using validated screening tools, and DSM-derived criteria to assess delirium. A meta-analysis was performed for each endpoint if at least two studies could be combined.

RESULTS

Sixteen articles met the abovementioned criteria. The incidence of delirium ranged from 5% to 39%. Various preoperative risk factors were identified that is, age (Random MD 3.96, CI 2.57-5.35), hypertension (Fixed OR 1.30, CI 1.05-1.59), diabetes mellitus (Random OR 2.15, CI 1.30-3.56), hearing impairment (Fixed OR 1.89, CI 1.28-2.81), history of cerebrovascular incident or transient ischemic attack (Fixed OR 2.20, CI 1.68-2.88), renal failure (Fixed OR 1.61, CI 1.19-2.17), and pre-operative low haemoglobin level (fixed MD -0.76, CI -1.04 to -0.47). Intra-operative risk factors were duration of surgery (Random MD 15.68; CI 2.79-28.57), open aneurysm repair (Fixed OR 4.99, CI 3.10-8.03), aortic cross clamping time (fixed MD 7.99, CI 2.56-13.42), amputation surgery (random OR 3.77, CI 2.13-6.67), emergency surgery (Fixed OR 4.84, CI 2.81-8.32) and total blood loss (Random MD 496.5, CI 84.51-908.44) and need for blood transfusion (Random OR 3.72, CI 1.57-8.80). Regional anesthesia on the other hand, had a protective effect. Delirium was associated with longer ICU and hospital length of stay, and more frequent discharge to a care facility.

CONCLUSIONS

POD after vascular surgery is a frequent complication and effect-size pooling supports the concept that delirium is a heterogeneous disorder. The risk factors identified can be used to either design a validated risk factor model or individual preventive strategies for high-risk patients.

Association between increased neutrophil-to-lymphocyte ratio and postoperative delirium in elderly patients with total hip arthroplasty for hip fracture

BACKGROUND

Delirium is a common complication in elderly patients with total hip arthroplasty (THA) for hip fracture. The mechanism of postoperative delirium (POD) is associated with the neuroinflammatory process. The aim of this study was to the incidence and perioperative risk factors of POD and investigate whether NLR could serve as a potential marker for POD in elderly patients with THA for hip fracture.

METHODS

This was a multicenter prospective study, we included elderly patients with THA for hip fracture under general anesthesia. Receiver operating characteristic (ROC) curve was performed to identify the optimal cut point of NLR for POD. The relationship between NLR and POD was analyzed by multivariable analysis.

RESULTS

Seven hundred eighty patients (mean age 73.33 ± 7.66) were eligible for inclusion in the study. 23.33% (182/780) of patients had POD. ROC curve analysis showed that the optimal cut point of NLR for POD was NLR ≥ 3.5. Compared with no POD, higher NLR, older age, diabetes, and higher neutrophil count were more likely in patients with POD(P < 0.05). Multivariate logistic regression analysis showed that NLR ≥ 3.50 [adjusted odds ratio(aOR), 3.93; confidence interval (CI), 2.47-6.25; P < 0.001)], older age (aOR, 1.04; 95%CI, 1.02-1.07; P = 0.001), diabetes (aOR, 1.58; 95% CI, 1.06-2.36; P = 0.025),higher neutrophil count (aOR, 1.25; 95%CI, 1.15-1.35; P < 0.001) were associated with increased risk of POD.

CONCLUSIONS

Older age, diabetes, higher neutrophil count, and NLR ≥ 3.5 were independent risk factors for POD, and NLR can be used as a potential marker for prediction of delirium in elderly patients with THA for hip fracture.

Postoperative Delirium after Urological Surgery: A Literature Review

Purpose

We aimed to thoroughly search and identify studies referring to risk factors associated with postoperative delirium (POD) in patients undergoing open as well as en-doscopic urological surgery.

Methods

The review after a systematic literature search included 5 studies.

Results

The incidence of POD was reported to be between 7.8 and 30% depending on the type of the urologic surgery, while in the majority of the studies the onset happened on the first postoperative day and the symptoms lasted 3 ± 0.8 days. Seventeen different risk factors for POD were identified and presented in detail.

Conclusion

The Mini-Mental State Examination score and older age were significantly associated with the development of POD. However, the Confusion Assessment Method is very well validated against the diagnosis of delirium from the specialists.

Postoperative delirium after hip surgery is a potential risk factor for incident dementia: A systematic review and meta-analysis of prospective studies

BACKGROUND

Although a few trials have explored the relationship between postoperative delirium (POD) and incident dementia in patients with hip surgery, the numbers of participants in each study are relatively small. Thus, we performed a meta-analysis to examine whether POD after hip surgery is a risk factor for incident dementia.

METHODS

Six prospective cohort studies investigating the development of incident dementia in patients with POD after hip surgery were retrieved from PubMed, Embase, and the Cochrane Library. We performed a pairwise meta-analysis using fixed- and random- effect models.

RESULTS

POD significantly increased the risk of incident dementia and cognitive decline (overall odds ratio [ORs] = 8.957; 95 % confidence interval [CI], 5.444-14.737; P <  0.001 in fixed-effects model; overall ORs = 8.962; 95 % CI, 5.344-15.029; P <  0.001 in random-effects model). A publication bias was not evident in this study.

CONCLUSIONS

Our meta-analysis revealed that POD after hip surgery is a risk factor for incident dementia. Early identification of cognitive function should be needed after surgery and appropriate prevention and treatment for dementia will be required, especially in cases with POD.

Evaluation of Postoperative Delirium: Validity and Reliability of the Nursing Delirium Screening Scale in the Turkish Language

PURPOSE

Postoperative delirium is the most well-known form of postoperative cognitive impairment in all patient groups, especially in the elderly. Delirium is a syndrome that causes serious consequences, increasing mortality and morbidity rates and extending the length of hospital stay. The aim of this study was to evaluate the validity and reliability of the Turkish version of the Nursing Delirium Screening Scale (Nu-DESC).

METHOD

One hundred twelve patients who were hospitalized for a surgical operation in the orthopedics, neurosurgery, and general surgery clinic of a state hospital for 3 months were evaluated concurrently (and independently for delirium). Patients were observed by clinical nurses 3 times over a 24-h period. The presence of delirium was diagnosed by 2 neurologists according to DSM-IV criteria. Student's t test, the χ2 test, and the Mann-Whitney U test were used, and construct validity, intrascale factor analysis, interrater reliability, and specificity and sensitivity (ROC) analyses were performed for descriptive analysis. SPSS 25.0 and MedCalc18.6 were used for statistical analysis.

RESULTS

Delirium was detected in 28 patients according to the Nu-DESC. The ICC (intraclass correlation) is 0.97 in the 95% confidence interval from 0.96 to 0.98 for agreement between nurses and neurologists for the total Nu-DESC score. Weighted κ rates were between 0.78 and 0.92. In the ROC analysis of the Nu-DESC scale, the optimum cutoff value calculated for the 1,344 observations and 112 patients was determined as >1 according to the maximum sensitivity and the specific situation. Sensitivity at the cut-off point was 92.27; specificity was determined as 92.72. The Youden index was found to be J = 0.845 (0 < J = 0.845 < 1).

CONCLUSION

We believe that Turkish translation of Nu-DESC is valid and reliable for clinicians, nurses, and researchers and will contribute to delirium studies.

The association of preoperative delirium with postoperative outcomes following hip surgery in the elderly

STUDY OBJECTIVE

To determine the association of preoperative delirium with postoperative outcomes following hip surgery in the elderly.

DESIGN

Retrospective cohort study.

SETTING

Postoperative recovery.

PATIENTS

8466 patients all of whom were 65 years of age or older undergoing surgical repair of a femoral fracture. Of the total population studied, 1075 had preoperative delirium. Of those with preoperative delirium, 746 were ASA class 3 or below and 327 were ASA class 4 or above. Of the 7391 patients without preoperative delirium, 5773 were ASA class 3 or below and 1605 were ASA class 4 or above. The remainder in each group was of unknown ASA class.

INTERVENTIONS

We used multivariable logistic regression to explore the association of preoperative delirium with 30-day postoperative outcomes. The odds ratio (OR) with associated 95% confidence interval (CI) was reported for each covariate.

MEASUREMENTS

Data was collected regarding the incidence of postoperative outcomes including: delirium, pulmonary complications, extended hospital stay, infection, renal complications, vascular complications, cardiac complications, transfusion necessity, readmission, and mortality.

MAIN RESULTS

After adjusting for potential confounders, the odds of postoperative delirium (OR 9.38, 95% CI 7.94-11.14), pulmonary complications (OR 1.83, 95% CI 1.4-2.36), extended hospital stay (OR 1.47, 95% CI 1.26-1.72), readmission (OR 1.27, 95% CI 1.01-1.59) and mortality (OR 1.92, 95% CI 1.54-2.39) were all significantly higher in patients with preoperative delirium compared to those without.

CONCLUSIONS

After controlling for potential confounding variables, we showed that preoperative delirium was associated with postoperative delirium, pulmonary complications, extended hospital stay, hospital readmission, and mortality. Given the lack of studies on preoperative delirium and its postoperative outcomes, our data provides a strong starting point for further investigations as well as the development and implementation of targeted risk-reduction programs.

Preoperative Age and Prognostic Nutritional Index Are Useful Factors for Evaluating Postoperative Delirium Among Patients With Adult Spinal Deformity

STUDY DESIGN

A retrospective study of postoperative delirium after adult spinal deformity (ASD) surgery.

OBJECTIVE

To identify the risk factors of post-ASD surgery delirium, including nutritional state before surgery.

SUMMARY OF BACKGROUND DATA

Recently, malnutrition was reported as one of the risk factors of delirium. The prognostic nutritional index (PNI) and controlling nutritional status index (CONUT) scores are simple methods of nutritional evaluation. However, there are no reports that verify that delirium is related to the PNI and CONUT score in patients who have undergone ASD surgery.

METHODS

A consecutive 319 patients who underwent ASD surgery were divided into a delirium group (group D) or nondelirium group (group ND). Preoperative risk factors, including PNI, were assessed.

RESULTS

Group D consisted of 30 patients and group ND consisted of 289 patients. There was significant difference in age (group D:group ND = 73:62, P = 0.000), serum albumin (4.2:4.3, P = 0.028), operative time (422:395 min, P = 0.029), PNI score (49:52, P = 0.011), and CONUT score (1.7:1.1, P = 0.046). Using multiple logistic regression analysis, we found significant risk factors for delirium to be age (P = 0.006, odds ratio = 1.11, 95% confidence interval = 1.03-1.19) and PNI (P = 0.003, odds ratio = 0.87, 95% confidence interval = 0.79-0.96). A receiver operating characteristic curve showed that the cut-off value of PNI and age for delirium were 49.7 and 68.5 years, respectively.

CONCLUSION

The risk factors of postoperative delirium after ASD surgery were PNI less than 49.7 and age more than 68.5 years. Patients who undergo ASD surgery beyond these preoperative cut-off values should be cautioned about delirium and be required to provide adequate informed consent.

LEVEL OF EVIDENCE

3.

Peri- and postoperative cognitive and consecutive functional problems of elderly patients

PURPOSE OF REVIEW

From an elderly patient's perspective, acute and chronic cognitive disturbances are among the most harmful complications that can occur following surgery. For elderly patients, these complications often mean the end of an independent life. This article focuses on this serious aspect, which is increasingly prevalent in our aging society. Cognitive disturbances are associated with severe outcome impairments and increased mortality. This article aims to provide a current overview regarding the diagnosis, pathophysiology, prevention, and treatment of this severe social problem.

RECENT FINDINGS

The current knowledge of risk factors, diagnosis, prevention, and treatment of postoperative delirium and postoperative cognitive dysfunction should help to raise awareness and improve the outcome of delirious patients, particularly in the elderly population.

SUMMARY

Especially in elderly patients, postoperative delirium constitutes a common, severe complication. Early diagnosis and supportive treatment are essential to improve outcome. To date, no pharmacological treatment strategy was effective, so that further research about the underlying pathophysiology and the development of treatment strategies are urgently required.

Incidence, prognostic factors and impact of postoperative delirium after major vascular surgery: A meta-analysis and systematic review

Although postoperative delirium is a common complication and increases patient care needs, little is known about the predictors and outcomes of delirium in patients having vascular surgery. This review aimed to determine the incidence, prognostic factors and impact of postoperative delirium in vascular surgical patients. MEDLINE and EMBASE were systematically searched for articles published between January 2000 and January 2016 on delirium after vascular surgery. The primary outcome was the incidence of delirium. Secondary outcomes were contributing prognostic factors and impact of delirium. Study quality and risk of bias was assessed using the QUIPS tool for systematic reviews of prognostic studies, and MOOSE guidelines for reviews of observational studies. Quantitative analyses of extracted data were conducted using meta-analysis where possible to determine incidence of delirium and prognostic factors. A qualitative review of outcomes was performed. Fifteen articles were eligible for inclusion. Delirium incidence ranged between 5% and 39%. Meta-analysis found that patients with delirium were older than those without delirium (OR 3.6, p<0.001). Prognostic factors predicting delirium included increased age (OR 1.04, p<0.001), pre-existing cognitive impairment (OR 9.8, p=0.01), hypertension, pre-existing depression and open aortic surgery. Delirious patients remained in hospital 6 days longer ( p<0.001) and had more complications than patients without delirium. Data were limited on the impact of procedure complexity, endovascular compared to open surgery or type of anaesthetic. Postoperative delirium occurs frequently, resulting in major morbidity for vascular patients. Improved quality of prognostic studies may identify modifiable peri-operative factors to improve quality of care for vascular surgical patients.

Risk factors for the development of delirium in alcohol dependence syndrome: Clinical and neurobiological implications

INTRODUCTION

Alcohol withdrawal delirium (AWD) or delirium tremens (DT) is associated with severe complications and high mortality. Prospectively identifying patients with increased risk of developing DT would have important preventive and therapeutic implications. Thus, the present study aimed to identify clinical risk factors predicting the development of DT.

MATERIALS AND METHODS

The study was a cross-sectional quasi-experimental one with equivalent control group, conducted at a tertiary hospital from August 2014 to May 2015. Forty adult male inpatients, diagnosed with DT, were compared with forty age- and sex-matched inpatients in alcohol withdrawal state without delirium. Assessments were done using confusion assessment method, Clinical Institute Withdrawal Assessment of Alcohol Scale, and Mini-Mental Status Examination. For group comparisons, Pearson's Chi-square test and independent sample t-test were used; logistic regression was applied to identify predictors followed by receiver operating characteristic curve analysis.

RESULTS

Heavy drinking (P = 0.005; odds ratio [OR]: 1.17, confidence interval [CI]: 1.05-1.31), continuous pattern of drinking (P = 0.027; OR: 4.67, CI: 1.19-18.33), past history of delirium (P = 0.009; OR: 552.8, CI: 4.88-625.7), alcohol-induced psychosis (P = 0.002; OR: 74.6, CI: 4.68-1190), and presence of cognitive deficits (P = 0.044; OR: 12.5, CI: 1.07-147.3) emerged as strong predictors of AWD.

CONCLUSION

The risk factors found can be easily evaluated in a clinical setting for physicians to readily identify patients at risk for developing DT and plan intensive therapies for them. At a neurobiological level, patients with preexisting brain neurotransmitter disturbances are at greater risk for developing DT.

A Systematic Review and Meta-analysis Examining the Impact of Incident Postoperative Delirium on Mortality

Background

Delirium is an acute and reversible geriatric syndrome that represents a decompensation of cerebral function. Delirium is associated with adverse postoperative outcomes, but controversy exists regarding whether delirium is an independent predictor of mortality. Thus, we assessed the association between incident postoperative delirium and mortality in adult noncardiac surgery patients.

Methods

A systematic search was conducted using Cochrane, MEDLINE/PubMed, Cumulative Index to Nursing and Allied Health Literature, and Embase. Screening and data extraction were conducted by two independent reviewers. Pooled-effect estimates calculated with a random-effects model were expressed as odds ratios with 95% CIs. Risk of bias was assessed using the Cochrane Risk of Bias Tool for Non-Randomized Studies.

Results

A total of 34 of 4,968 screened citations met inclusion criteria. Risk of bias ranged from moderate to critical. Pooled analysis of unadjusted event rates (5,545 patients) suggested that delirium was associated with a four-fold increase in the odds of death (odds ratio = 4.12 [95% CI, 3.29 to 5.17]; I2 = 24.9%). A formal pooled analysis of adjusted outcomes was not possible due to heterogeneity of effect measures reported. However, in studies that controlled for prespecified confounders, none found a statistically significant association between incident postoperative delirium and mortality (two studies in hip fractures; n = 729) after an average follow-up of 21 months. Overall, as study risk of bias decreased, the association between delirium and mortality decreased.

Conclusions

Few high-quality studies are available to estimate the impact of incident postoperative delirium on mortality. Studies that controlled for prespecified confounders did not demonstrate significant independent associations of delirium with mortality.

Dementia With Lew Body: Impacts of Surgery

Patients who have dementia with Lewy bodies (DLB) and undergo surgery may develop aggravated postoperative cognitive dysfunction or postoperative delirium. Many patients with DLB respond poorly to surgery and anesthesia, and their conditions may worsen if they have other medical complications along with dementia. They may also face high risk of prolonged hospital stay, increased medical problems and/or mortality, causing significant physical, psychosocial, and financial burdens on individuals, family members, and society. Anesthesia, pain medications, old age, and surgery-related stresses are usually held responsible for the complications; however, the exact causes are still not fully understood. Literature on surgery-related complications for patients with DLB appears to be inadequate, and hence the topic merits detailed and systematic research. This article reviews postoperative complications and various surgery-related risk factors for DLB in light of other dementias such as Alzheimer's disease, as their neuropathologic features overlap with those of DLB.

Short-Form Mini Nutritional Assessment as a useful method of predicting the development of postoperative delirium in elderly patients undergoing orthopedic surgery

OBJECTIVE

Postoperative delirium (POD) is a major cause for concern among elderly patients undergoing surgery, often resulting in poor outcome. It is therefore important to predict and prevent POD. The aim of this study was to evaluate the Mini Nutritional Assessment Short-Form (MNA-SF) as a predictor of POD after orthopedic surgery.

METHODS

Elderly patients undergoing orthopedic surgery between April 2011 and March 2013 were included in the study (n=544; mean age, 74.24 ± 7.92 years). The MNA-SF was used to evaluate preoperative nutritional status. Delirium was assessed daily after surgery using the confusion assessment method. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria were used to confirm delirium diagnosis. Univariate and multivariate logistic regression analyses were performed to identify key factors associated with POD.

RESULTS

POD occurred in 52 patients (9.6%). According to the MNA-SF, 17.5% of subjects were at risk of undernutrition. Adjusting for all potential factors in the final model, age, male gender and lower Mini-Mental State Examination and higher Charlson Comorbidity Index scores were associated with significantly increased likelihood of POD. Subjects who were identified preoperatively as at risk of undernutrition were 2.85 times more likely to develop POD compared to normally nourished subjects (odds ratio: 2.85, 95% confidence interval: 1.19-6.87).

CONCLUSIONS

These results suggest that the MNA-SF is a simple and effective tool that can be used to predict incident delirium in elderly patients after orthopedic surgery.

Biomarkers of postoperative delirium and cognitive dysfunction

Elderly surgical patients frequently experience postoperative delirium (POD) and the subsequent development of postoperative cognitive dysfunction (POCD). Clinical features include deterioration in cognition, disturbance in attention and reduced awareness of the environment and result in higher morbidity, mortality and greater utilization of social financial assistance. The aging Western societies can expect an increase in the incidence of POD and POCD. The underlying pathophysiological mechanisms have been studied on the molecular level albeit with unsatisfying small research efforts given their societal burden. Here, we review the known physiological and immunological changes and genetic risk factors, identify candidates for further studies and integrate the information into a draft network for exploration on a systems level. The pathogenesis of these postoperative cognitive impairments is multifactorial; application of integrated systems biology has the potential to reconstruct the underlying network of molecular mechanisms and help in the identification of prognostic and diagnostic biomarkers.

Predicting postoperative delirium after vascular surgical procedures

OBJECTIVE

The objective of this study was to determine the incidence of and specific preoperative and intraoperative risk factors for postoperative delirium (POD) in electively treated vascular surgery patients.

METHODS

Between March 2010 and November 2013, all vascular surgery patients were included in a prospective database. Various preoperative, intraoperative, and postoperative risk factors were collected during hospitalization. The primary outcome variable was the incidence of POD. Secondary outcome variables were any surgical complication, hospital length of stay, and mortality.

RESULTS

In total, 566 patients were prospectively evaluated; 463 patients were 60 years or older at the time of surgery and formed our study cohort. The median age was 72 years (interquartile range, 66-77), and 76.9% were male. Twenty-two patients (4.8%) developed POD. Factors that differed significantly by univariate analysis included current smoking (P = .001), increased comorbidity (P = .001), hypertension (P = .003), diabetes mellitus (P = .001), cognitive impairment (P < .001), open aortic surgery or amputation surgery (P < .001), elevated C-reactive protein level (P < .001), and blood loss (P < .001). Multivariate logistic regression analysis revealed preoperative cognitive impairment (odds ratio [OR], 16.4; 95% confidence interval [CI], 4.7-57.0), open aortic surgery or amputation surgery (OR, 14.0; 95% CI, 3.9-49.8), current smoking (OR, 10.5; 95% CI, 2.8-40.2), hypertension (OR, 7.6; 95% CI, 1.9-30.5) and age ≥80 years (OR, 7.3; 95% CI, 1.8-30.1) to be independent predictors of the occurrence of POD. The combination of these parameters allows us to predict delirium with a sensitivity of 86% and a specificity of 92%. The area under the curve of the corresponding receiver operating characteristics was 0.93. Delirium was associated with longer hospital length of stay (P < .001), more frequent and increased intensive care unit stays (P = .008 and P = .003, respectively), more surgical complications (P < .001), more postdischarge institutionalization (P < .001), and higher 1-year mortality rates (P = .0026).

CONCLUSIONS

In vascular surgery patients, preoperative cognitive impairment and open aortic or amputation surgery were highly significant risk factors for the occurrence of POD. In addition, POD was significantly associated with a higher mortality and more institutionalization. Patients with these risk factors should be considered for high-standard delirium care to improve these outcomes.

Postoperative course after emergency colorectal surgery for secondary peritonitis in the elderly is often complicated by delirium

Postoperative delirium, morbidity, and mortality in our elderly patients with secondary perionitis of colorectal origin is described. This is a chart-based retrospective analysis of 63 patients who were operated on at the University Hospital Basel from April 2001 to May 2004. Postoperative delirium occurred in 33%. Overall morbidity was 71.4%. Surgery-related morbidity was 43.4%. Mortality was 14.4%. There was no statistical significance between delirium, morbidity and mortality (P  =  0.279 and P  =  0.364). There was no statistically significant correlation between the analyzed scores (American Society of Anesthesiologists classification, Mannheimer Peritonitis Index, Acute Physiology and Chronic Health Evaluation score II, physiological and operative surgical severity and enumeration of morbidity and mortality score' or short 'cr-POSSUM') and postoperative delirium, morbidity or mortality. Postoperative delirium occurred in one-third of the patients, who seem to have a trend to higher morbidity. Even if the different scores already had proven to be predictive in terms of morbidity and mortality, they do not help the risk stratification of postoperative delirium, morbidity, or mortality in our collective population.

Elective treatment of abdominal aortic aneurysm is reasonable in patients >85 years of age

BACKGROUND

The numbers of patients >85 years of age referred for abdominal aortic aneurysm (AAA) repair have increased in recent decades. With the population aging, increased screening of AAA, and introduction of less invasive surgical techniques, vascular surgeons will be treating more elderly patients. Few data are available for estimating the risks and benefits of prophylactic repair among those with such an advanced age. The aim of this single-center study was to evaluate the short-term to midterm results after AAA repair in patients >85 years of age.

METHODS

Between 2004 and 2012, data of patients >85 years old who required an elective AAA repair at our institution were collected prospectively. According to the current guidelines, patients underwent endovascular aneurysm repair (EVAR) each time the aortic anatomy was suitable. Open repair (OR) was performed in those patients with hostile proximal neck anatomy and/or severe iliac tortuosity. Type of repair (EVAR or OR) and perioperative and midterm outcomes were analyzed. Primary end points were 30-day mortality and midterm survival.

RESULTS

Among 1016 patients undergoing elective AAA repair during the study period, 59 (5.8%) were ≥85 years of age (54 men, mean age 87 ± 2 years), with a mean aneurysm diameter of 61.5 ± 20.3 mm. Thirty-three patients (56%) underwent EVAR and 26 (44%) had an OR. Thirty-day mortality was 6.7% (6% with EVAR and 7.6% with OR, P <0.05). Mean follow-up was 24.7 ± 18 months. Kaplan‒Meier analyses for survival were 85.5%, 64.5%, and 50% at 1, 3, and 5 years, respectively. No aneurysm-related death was observed during follow-up.

CONCLUSION

Elective repair may be proposed in patients >85 years of age in cases of threatening AAA, showing acceptable perioperative mortality and reasonable midterm survival results. Even if EVAR did not seem to offer significant benefits in perioperative mortality in our study, it appears reasonable to suggest this less invasive technique as first-line treatment in cases of suitable anatomy in such an advanced-age population.

Anaemia in the older surgical patient: a review of prevalence, causes, implications and management

This review provides the clinician with a summary of the causes, implications and potential treatments for the management of anaemia in the older surgical patient. The prevalence of anaemia increases with age and is frequently identified in older surgical patients. Anaemia is associated with increased postoperative morbidity and mortality. Allogenic blood transfusion is commonly used to treat anaemia but involves inherent risks and may worsen outcomes. Various strategies for the correction of pre- and postoperative anaemia have evolved. These include correction of nutritional deficiencies and the use of intravenous iron and erythropoesis stimulating therapy. Clear differences exist between the elective and emergency surgical populations and the translation of research findings into these individual clinical settings requires more work. This should lead to a standardized approach to the management of this frequently encountered clinical scenario.

Association of pre-operative brain pathology with post-operative delirium in a cohort of non-small cell lung cancer patients undergoing surgical resection

OBJECTIVE

Post-operative delirium is associated with pre-operative cognitive difficulties and diminished functional independence, both of which suggest that brain pathology may be present in affected individuals prior to surgery. Currently, there are few studies that have examined imaging correlates of post-operative delirium. To our knowledge, none have examined the association of delirium with existing structural pathology in pre-operative cancer patients. Here, we present a novel, retrospective strategy to assess pre-operative structural brain pathology and its association with post-operative delirium. Standard of care structural magnetic resonance imaging (MRIs) from a cohort of surgical candidates prior to surgery were analyzed for white matter hyperintensities and cerebral atrophy.

METHODS

We identified 23 non-small cell lung cancer patients with no evidence of metastases in the brain pre-operatively, through retrospective chart review, who met criteria for post-operative delirium within 4 days of surgery. 24 age- and gender-matched control subjects were identified for comparison to the delirium sample. T1 and fluid-attenuated inversion recovery sequences were collected from standard of care pre-operative MRI screening and assessed for white matter pathology and atrophy.

RESULTS

We found significant differences in white matter pathology between groups with the delirium group exhibiting significantly greater white matter pathology than the non-delirium group. Measure of cerebral atrophy demonstrated no significant difference between the delirium and non-delirium group.

CONCLUSIONS

In this preliminary study utilizing standard of care pre-operative brain MRIs for assessment of structural risk factors to delirium, we found white matter pathology to be a significant risk factor in post-operative delirium. Limitations and implications for further investigation are discussed.

The relation between atherosclerosis and the occurrence of postoperative delirium in vascular surgery patients

Old and frail patients undergoing vascular surgery seem at great risk of developing postoperative delirium (POD). The aim of this review was to identify risk factors for the development of POD in vascular surgery patients. Different aetiological factors have been identified, such as increased age, excessive blood transfusion, preoperative cognitive impairment and depression. Mounting evidence supports a role for inflammation and tobacco exposure in the development of POD. Vascular surgery patients differ from the general surgical population because they suffer from both loco-regional and systemic atherosclerosis. Although current scientific evidence cannot fully link both entities, evidence is growing that suggests a relationship between systemic and cerebrovascular atherosclerosis and the development of POD.

Risk factors for postoperative cognitive and functional difficulties in abdominal aortic aneurysm patients: a three month follow-up

BACKGROUND

Cognitive impairment and deficits in functional performance are major concerns following surgery, particularly for older patients. The objective of this study was to examine predictors of postoperative cognitive and functional difficulties and explore the relationship between presurgery and postsurgery cognitive ability and functional performance.

METHODS

89 patients undergoing elective abdominal aortic aneurysm (AAA) surgery were administered a battery of cognitive measures preoperatively, at the time of discharge from hospital and 3 months postoperatively. Functional performance was evaluated by the Portland Adaptability Inventory (PAI), both pre and postsurgery. Symptoms of delirium were assessed during the first six postoperative days.

RESULTS

A diagnosis of delirium had a mild effect on functional performance 3 months postoperatively. The strongest predictors of postoperative functional performance were the level of functioning presurgery, a longer length of hospital stay and the total number of days delirious. Cognitive impairment postsurgery was predicted by presurgery cognitive measures of verbal memory and psychomotor speed performance and the total number of days delirious.

CONCLUSIONS

Functional performance outcomes for AAA patients 3 months postsurgery revealed no significant loss of functioning relative to presurgery levels, although longer length of hospital stay and greater number of days delirious was associated with somewhat poorer outcome on indicators of social and physical functioning. Cognitive impairment postoperatively was fairly mild but when it was found it was associated with number of days delirious and preoperative deficits in verbal memory and psychomotor speed.

Medical consultation and best practices for preoperative evaluation of elderly patients

Preoperative evaluation of elderly patients is an important component of surgical practice in the 21st century. It can offer a comprehensive geriatric evaluation and be a key element in decreasing postoperative morbidity and mortality in this unique population group. Advanced surgical and anesthetic techniques have contributed to an increasing number of elderly and sicker geriatric patients undergoing surgery. Elderly patients have limited physiologic reserve and pose many challenges in the perioperative setting, and a careful preoperative risk assessment aimed toward minimizing operative risks is essential. Advanced age increases the risk of developing complications post-surgery, but comorbidities are more important than age alone. General recommendations include avoiding drugs that increase the risk of delirium, ensuring appropriate hydration and calorie intake, minimizing bed rest, promoting ambulation, and early planning for discharge. Collaboration between surgeons and medical consultants aids in the identification of functional, cognitive, and nutritional deficits, provides structure for development and implementation of management plans, and promotes optimal patient outcome after surgical intervention in the elderly.

White matter abnormalities as a risk factor for postoperative delirium revealed by diffusion tensor imaging

OBJECTIVE

Delirium is a common and critical clinical syndrome in older persons. The authors examined whether any abnormalities in the white matter (WM) assessed by diffusion tensor imaging (DTI) predisposes patients to develop delirium after cardiac surgery and also analyzed other risk factors for delirium.

METHOD

In 116 consecutive patients who underwent scheduled cardiac operations, fractional anisotropy (FA) values obtained by DTI before the surgery and pre-, peri-, and postoperative factors were evaluated. The postoperative delirium was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for delirium.

RESULTS

Delirium developed in 19 of 116 patients (16.4%). Eighteen of the patients with delirium (94.7%) were older than 60 years. A multivariate logistic regression analysis showed that advanced age and poor performance on a semantic fluency task (the Word Fluency test animal) were important predictive indicators of the delirium. In addition, a voxel-by-voxel analysis using the Statistical Parametrical Mapping 2 revealed that the FA values of the patients with postoperative delirium were significantly lower than those of the nondelirium patients in the bilaterally widespread deep WMs and bilateral thalamus, whereas the analysis treating age as a nuisance variable indicated a significant change in only four clusters of the brain areas, e.g., the left frontal lobe WM, and left thalamus, when compared with the nondelirium group.

CONCLUSION

The abnormalities in the deep WMs and thalamus that were mainly accelerated by aging may account for the vulnerability to postoperative delirium, and the semantic word fluency could be a useful predictive indicator of delirium.

Delirium following acute myocardial infarction: incidence, clinical profiles, and predictors

PURPOSE

To examine the incidence, clinical profile, and predictors of delirium following acute myocardial infarction (MI).

DESIGN AND METHODS

The study sample included 212 consecutive patients with acute MI who were admitted to the coronary intensive care unit of a university hospital.

FINDINGS

Delirium was found to occur in 5.7% of the patients. The predictors of delirium were advanced age, higher level of serum potassium at admission, and experience of cardiac arrest during MI.

PRACTICE IMPLICATIONS

Delirium is reasonably prevalent in patients with acute MI. We propose that patients with the risk factors that have been delineated in this study should be evaluated carefully.

Pharmacological treatment for the prevention of delirium: review of current evidence

OBJECTIVE

Delirium is a very common and serious disorder with high morbidity and mortality. Despite symptomatic treatment the outcome can be poor for some especially when no underlying cause is identified. As a result, various strategies for delirium prevention have been assessed. Pharmacological agents such as antipsychotics, acetylcholinesterase inhibitors, sleep-wake cycle regulators, anti-inflammatories and others have been advocated for a potential role in delirium prevention. The aim of this paper is to review the available evidence for their use in the prevention of delirium.

METHODS

An electronic search was carried out using Medline, EMBASE and Cochrane for randomised controlled trials (RCTs) and other studies. The words delirium, prevention, intervention, pharmacological, prophylactic, antipsychotics, acetylcholinesterase inhibitors, sleep and anti-inflammatories were used. References from selected papers were also searched.

RESULTS

No multi-centre RCT has been identified. Few trials and other studies have been published so far assessing the prophylactic role of antipsychotics, acetylcholinesterase inhibitors, hypnotics, melatonin, and gabapentin. As these studies tested different drugs, regimes and protocols in diverse populations no meaningful comparison can be made.

CONCLUSION

To date there is conflicting and inconsistent data regarding the efficacy of pharmacological treatment for delirium prevention. Positive reports in few of the studies justify further assessment of the potential for some pharmacological agents in the prevention of delirium. Well designed and appropriately powered RCTs are now needed. However, based on available evidence so far, no recommendation can be made to justify the routine clinical prophylactic use of any pharmacological agent in the prevention of delirium.

Preliminary results of a prospective randomized trial of restrictive versus standard fluid regime in elective open abdominal aortic aneurysm repair

BACKGROUND

Open abdominal aortic aneurysm (AAA) repair is associated with a significant morbidity (primarily respiratory and cardiac complications) and an overall mortality rate of 4% to 10%. We tested the hypothesis that perioperative fluid restriction would reduce complications and improve outcome after elective open AAA repair.

METHODS

In a prospective randomized control trial, patients undergoing elective open infra-renal AAA repair were randomized to a "standard" or "restricted" perioperative fluid administration group. Primary outcome measure was rate of major complications (MC) after AAA repair and secondary outcome measures included: Sequential Organ Failure Assessment Score; FiO2/PO2 ratio; Urinary Albumin/Creatinine Ratio; Length-of-stay in, intensive care unit, high dependency unit, in-hospital. This prospective Randomized Controlled Trial was registered in a publicly accessible database and has the following ID number ISRCTN27753612.

RESULTS

Overall 22 patients were randomized, 1 was excluded on a priori criteria, leaving standard group (11) and restricted group (10) for analysis. No significant difference was noted between groups in respect to age, gender, American Society Anesthesiology class, Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity scores, operation time, and operation blood loss. There were no in-hospital deaths and no 30-day mortality. The cumulative fluid balance on day 5 postoperative was for standard group, 8242 +/- 714 mL, compared with restricted group, 2570 +/- 977 mL, P < 0.01. MC were significantly reduced in the restricted group (n = 10), 1 MC, compared with standard group (n = 11), 14 MC, P < 0.024. Total and postoperative length-of-stay in-hospital was significantly reduced in the restricted group, 9 +/- 1 and 8 +/- 1 days, compared with standard group, 18 +/- 5 and 16 +/- 5 days, P < 0.01 and P < 0.025, respectively.

CONCLUSIONS

Serious complications are common after elective open AAA repair, and we have shown for the first time that a restricted perioperative fluid regimen can prevent MC and significantly reduce overall hospital stay.

Non-pharmacological interventions in the prevention of delirium

Delirium is a serious and common disorder especially among older people on inpatients units. Numerous modifiable or manageable delirium risk factors have been identified. As a result, there is now a widespread notion that many cases of delirium can be prevented. In this review, published data evaluating non-pharmacological interventions for delirium prevention were assessed in relation to their efficacy. Currently, most published studies are based on direct targeting of risk factors and/or introduction of educational programmes to increase staff knowledge and awareness. However, there continues to be a dearth of randomised controlled trials evaluating non-pharmacological interventions, partly because of the inherent difficulties associated with delirium research in general and with the evaluation of non-pharmacological interventions in particular. Instead, many of the available studies have been observational or non-randomised in nature. Nevertheless, the majority of these support a role for non-pharmacological interventions in delirium prevention. While more research is certainly needed, the majority of available data are based on best practice protocols, guidelines and interventions. Hence, a consistent and concerted effort is now justified to introduce non-pharmacological prevention strategies across units to help tackle the increasingly prevalent delirium among older people.

Overcoming barriers to osteoporosis care in vulnerable elderly patients with hip fractures

Indications for and benefits of providing osteoporosis (OP) care for hip fracture patients have become widely understood. The hip fracture patient is frequently over age 80 years, minimally ambulatory, has multiple medical comorbidities, and has cognitive impairment. Patient barriers to initiation of effective OP treatment include: age, dementia, medical comorbidities, polypharmacy, lack of adherence with treatment, alcohol abuse, postoperative delirium, language barriers, inadequate social support, and socioeconomic status. In a large teaching hospital, 244 patients presented with hip fracture over 2 years: 72% were female and 64% were over age 80. Forty percent had been diagnosed with dementia; another 29% had other severe medical comorbidities.Opportunities for OP diagnosis and treatment are numerous. In acute care hospitals, coordinator facilitated programs are effective for identification, education, assessment, referral, and treatment of underlying OP in fracture patients. System modifications may include an automated care path or automatic specialist referral for hip fracture patients. In the rehabilitation hospital, the patients are in a more stable condition, there is a focus on the recent fracture, and there are opportunities to initiate OP treatment and to promote adherence. In long-term care, dietary intake including calcium and vitamin D supplementation and persistence with pharmacotherapy can be monitored. Patient education and referral to the family physician for osteoporosis investigation and treatment have improved patient knowledge and diagnosis, but the reported impact on treatment has been limited.Effective OP care for the vulnerable hip fracture patient should be initiated early but may be complex and require coordination. In addition to calcium and vitamin D supplementation, most patients in this category have an indication for aminobisphosphonate therapy. Liaison between the orthopaedic team and the discharge destination caregivers, an established discharge diagnosis of osteoporosis, and ensuring patients are discharged on supplements and medication will promote patient, caregiver, and primary care physician awareness of the patient's OP care needs. Education programs may provide benefits at later stages, to improve adherence with treatment.

Delirium resolution in hospitalized older patients with cancer

Delirium is a troubling complication in hospitalized older patients with cancer. Although preventable and potentially reversible, delirium may be prolonged. Persistent delirium at the time of hospital discharge is common and associated with multiple adverse outcomes. We conducted a secondary data analysis to examine delirium resolution in 43 hospitalized older patients with cancer who had prevalent or incident delirium. We describe trajectories of delirium resolution and evaluate differences in patients with and without delirium resolution. Delirium was assessed using the NEECHAM confusion scale. Forty-one of the 43 patients had delirium during hospitalization before discharge; 2 had delirium only at the time of discharge. Although delirium resolved in 13 patients, a significant majority (70%) had delirium at discharge. Patients with delirium resolution were less functionally impaired before hospitalization and exhibited fewer etiologic risk patterns at admission. Mild delirium was more likely to resolve than severe delirium. All patients with chronic cognitive impairment had persistent delirium. Care for hospitalized older patients with cancer should incorporate delirium prevention and intervention strategies. Caregiver education, communication between providers, and follow-up are critical when delirium persists. Additional research focusing on the management and impact of persistent delirium in hospitalized older patients with cancer is needed.

Pharmacologic management of the older woman undergoing surgery

Surgical intervention for both emergency and elective surgeries will increase as women live longer and maintain active lifestyles. Older women with operable conditions tolerate elective gynecologic and other nonvascular surgery with acceptable morbidity and mortality. However, increased medical comorbidities, with their associated increase in polypharmacy and perioperative risks as women age, make it important to a priori optimize perioperative medical conditions and medication management. Other considerations include assessing functional and cognitive status, since these may be impaired acutely with increased prevalence of drug use during surgical hospitalization. With aging and postmenopausal status, changes associated with aging appear to play a greater role than gender in pharmacologic responses. Surgical outcomes should be optimized to maintain and even improve women's quality of life.

Predisposing and precipitating factors for delirium in a frail geriatric population

OBJECTIVE

The aim of this study was to assess the possible predisposing aetiologic and short-term precipitating factors for delirium in acutely ill hospital patients with a heavy burden of comorbidities and medications.

METHODS

Eighty-seven consecutive patients with acute delirium admitted to a general medicine unit were thoroughly examined, and the predisposing and precipitating factors of their delirium were assessed.

RESULTS

In this population, an average of 5.2 predisposing factors and 3.0 potential precipitating factors for delirium was revealed, meaning an average of over eight possible aetiological causes for each patient. The most common precipitating factors were infections (n=72), metabolic abnormalities (n=52), adverse drug effects (n=41), and cardiovascular events (n=38). In addition, a number of very rare conditions were diagnosed after thorough assessments.

CONCLUSION

Geriatric patients with acute delirium typically present with several concomitant predisposing factors for delirium exposing them to high vulnerability for the syndrome. In most patients, a number of possible etiological causes for delirium can be identified after a careful assessment, but their true pathogenetic pathway to the syndrome is unclear.

Incidence and predictors of post-cardiotomy delirium

OBJECTIVE

To determine the incidence and predictors of delirium after cardiac surgery.

METHOD

A prospective, observational study of postcardiotomy surgical patients was conducted during a 5 month period at the Minneapolis, MN, VAMC.

RESULTS

Of the 53 patients who completed the study, 12 patients (23%) met criteria for postoperative delirium and 18 patients (34%) met criteria for postoperative subsyndromal delirium. Significant predictors of postoperative delirium included a history of cerebrovascular disease (Charlson Index item, VA CICSP), high medical comorbidity (VA morbidity risk score, Charlson Index), increased preoperative creatinine level, and an increased preoperative pain rating. When delirium and subsyndromal delirium patients were combined, a history of cerebrovascular disease, left ventricular dysfunction, or diabetes predicted the development of delirious symptoms.

CONCLUSIONS

Incident delirium occurred in 23% of patients after cardiac surgery and incident delirium symptoms, in 57%. The strongest predictor of both incident delirium and delirium symptoms was a history of cerebrovascular disease.