Postoperative Delirium: Risk Factors, Prevention, and Treatment

Lower alpha frequency of intraoperative frontal EEG is associated with postoperative delirium: A secondary propensity-matched analysis

BACKGROUND

Postoperative delirium (POD) is a serious complication of surgery, especially in the elderly patient population. It has been proposed that decreasing the amount of anesthetics by titrating to an EEG index will lower POD rate, but clear evidence is missing. A strong age-dependent negative correlation has been reported between the peak oscillatory frequency of alpha waves and end-tidal anesthetic concentration, with older patients generating slower alpha frequencies. We hypothesized, that slower alpha oscillations are associated with a higher rate of POD.

METHOD

Retrospective analysis of patients` data from a prospective observational study in cardiac surgical patients approved by the Bernese Ethics committee. Frontal EEG was recorded during Isoflurane effect-site concentrations of 0.7 to 0.8 and peak alpha frequency was measured at highest power between 6 and 17 Hz. Delirium was assessed by chart review. Demographic and clinical characteristics were compared between POD and non-POD groups. Selection bias was addressed using nearest neighbor propensity score matching (PSM) for best balance. This incorporated 18 variables, whereas patients with missing variable information or without an alpha oscillation were excluded.

RESULT

Of the 1072 patients in the original study, 828 were included, 73 with POD, 755 without. PSM allowed 328 patients into the final analysis, 67 with, 261 without POD. Before PSM, 8 variables were significantly different between POD and non-POD groups, none thereafter. Mean peak alpha frequency was significantly lower in the POD in contrast to non-POD group before and after matching (7.9 vs 8.9 Hz, 7.9 vs 8.8 Hz respectively, SD 1.3, p < 0.001).

CONCLUSION

Intraoperative slower frontal peak alpha frequency is independently associated with POD after cardiac surgery and may be a simple intraoperative neurophysiological marker of a vulnerable brain for POD. Further studies are needed to investigate if there is a causal link between alpha frequency and POD.

Influence of perioperative blood pressure regulation on postoperative delirium in patients undergoing head and neck free flap reconstruction

BACKGROUND

Postoperative delirium (POD) is a serious complication in patients undergoing microvascular head and neck reconstruction. Whether intraoperative and postoperative blood pressure regulation are risk factors for POD remains unclear. This study aimed to highlight the relationships between intraoperative and postoperative blood pressure regulation and POD in microvascular head and neck reconstruction.

METHODS

Data from 433 patients who underwent microvascular head and neck reconstruction at our department of oral and maxillofacial surgery between 2011 and 2019 were retrospectively analyzed. The 55 patients with POD were matched with 55 patients without POD in terms of tracheotomy, flap type, and flap location, and the intraoperative and postoperative systolic and mean blood pressure values were compared between the two groups.

RESULTS

Patients with POD showed lower intraoperative and postoperative minimum mean arterial pressure (MAP) values than patients without POD (60.0 mmHg vs. 65.0 mmHg, p < 0.001; and 56.0 mmHg vs. 62.0 mmHg, p < 0.001; respectively). A lower intraoperative minimum MAP value was identified as predictor for POD (odds ratio [OR] 1.246, 95% confidence interval [CI] 1.057-1.472, p = 0.009). The cut-off value for intraoperative MAP for predicting POD was  ≤ 62.5 mmHg (area under the curve [AUC] 0.822, 95% CI 0.744-0.900, p < 0.001).

CONCLUSIONS

Maintaining a stable intraoperative minimum MAP of  > 62.5 mmHg could help to reduce the incidence of POD in microvascular head and neck reconstruction.

Development and Validation of a Delirium Risk Prediction Model for Elderly Patients Undergoing Elective Orthopedic Surgery

Purpose

This study aimed to develop and validate a post-operative delirium (POD) nomogram in a population of elderly patients undergoing elective orthopedic surgery.

Patients and Methods

A predictive model was developed based on a training dataset of 474 elderly patients undergoing elective orthopedic surgery from March 2021 to May 2022. POD was identified using the Confusion Assessment Methods (CAM). The least absolute shrinkage and selection operator (LASSO) method was used to screen risk factors, and prediction models were created by combining the outcomes with logistic regression analysis. We employ bootstrap validation for internal validation to examine the model's repeatability. The results were validated using a prospective study on 153 patients operated on from January 2022 to May 2022 at another institution.

Results

The predictors in the POD nomogram included age, the Mini-Mental State Examination(MMSE), sleep disorder, neurological disorders, preoperative serum creatinine (Pre-SCR), and ASA classification. The c-index of the model was 0.928 (95% confidence interval 0.898 ~ 0.957) and the bootstrap validation still achieved a high c-index of 0.912. The c-index of the external validation was 0.921. The calibration curve for the diagnostic probability showed good agreement between prediction by nomogram and actual observation.

Conclusion

By combining preoperative and intraoperative clinical risk factors, we created a POD risk nomogram to predict the probability of POD in elderly patients who undergo elective orthopedic surgery. It could be a tool for guiding individualized interventions.

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.

Prevalence of Emergence Delirium and Associated Factors among Older Patients Who Underwent Elective Surgery: A Multicenter Observational Study

Background

Emergence delirium is a common and serious postoperative complication in older surgical patients. It occurs at any time in the perioperative period, during or immediately following emergence from general anesthesia. Unfortunately, it is highly associated with postoperative complications such as a decrease in functional capacity, prolonged hospital stay, an increase in health care costs, and morbidity and mortality. The goal of this study was to determine the prevalence of emergence delirium and associated factors among older patients who underwent elective surgery in the teaching hospitals of Ethiopia at the postanesthesia care unit in 2021.

Methods

A multicenter prospective observational study was conducted at the postanesthetic care unit in the four teaching hospitals of Ethiopia. Older surgical patients admitted to the postanesthesia care unit who underwent elective surgery in the four teaching hospitals of Ethiopia were selected by using simple random sampling. Pretested structured questionnaire was used to collect data. Data were entered into EpiData (version 4.6) and exported to the SPSS (version 25.0). Binary logistic regression was used to identify factors independently associated with the emergence delirium.

Results

Out of 384 older patients included in the study, the prevalence of emergence delirium was 27.6%. Preoperative low hemoglobin levels (AOR: 2.0, 95% CI; 1.77–3.46), opioid (AOR: 8.0, 95% CI; 3.22–27.8), anticholinergic premedications (AOR: 8.5, 95% CI; 6.85–17.35), and postoperative pain (AOR: 3.10, 95 CI; 2.07–9.84) at PACU were independently associated with emergence delirium.

Conclusion

The prevalence of emergence delirium was high among older patients who underwent elective surgery. Opioid and anticholinergic premedication, low preoperative hemoglobin, and the presence of postoperative pain were independently associated with the emergence delirium. Adequate preoperative optimization and postoperative analgesia may reduce the prevalence of emergence delirium.

Neuromonitoring depth of anesthesia and its association with postoperative delirium

Delirium after surgery or Postoperative delirium (POD) is an underdiagnosed entity, despite its severity and high incidence. Patients with delirium require a longer hospital stay and present more postoperative complications, which also increases hospital costs. Given its importance and the lack of specific treatment, multifactorial preventive strategies are evidenced based. Our hypothesis is that using general anaesthesia and avoiding the maximum time in excessively deep anaesthetic planes through BIS neuromonitoring device will reduce the incidence of postoperative delirium in patients over the age of 65 and their hospitalization stay. Patients were randomly assigned to two groups: The visible BIS group and the hidden BIS neuromonitoring group. In the visible BIS group, the depth of anaesthesia was sustained between 40 and 60, while in the other group the depth of anaesthesia was guided by hemodynamic parameters and the Minimum Alveolar Concentration value. Patients were assessed three times a day by research staff fully trained during the 72 h after the surgery to determine the presence of POD, and there was follow-up at 30 days. Patients who developed delirium (n = 69) was significantly lower in the visible BIS group (n = 27; 39.1%) than in the hidden BIS group (n = 42, 60.9%; p = 0.043). There were no differences between the subtypes of delirium in the two groups. Patients in the hidden BIS group were kept for 26.6 ± 14.0 min in BIS values < 40 versus 11.6 ± 10.9 min (p < 0.001) for the patients in the visible BIS group. The hospital stay was lower in the visible BIS group 6.56 ± 6.14 days versus the 9.30 ± 7.11 days (p < 0.001) for the hidden BIS group, as well as mortality; hidden BIS 5.80% versus visible BIS 0% (p = 0.01). A BIS-guided depth of anaesthesia is associated with a lower incidence of delirium. Patients with intraoperative neuromonitoring stayed for a shorter time in excessively deep anaesthetic planes and presented a reduction in hospital stay and mortality.

Can really plasma interleukin-6 predict postoperative delirium among patients undergoing open repair surgery of acute type A aortic dissection?

The letter to the editor was written in response to “Plasma interleukin-6 is a potential predictive biomarker for postoperative delirium (POD) among acute type a aortic dissection patients treated with open surgical repair”, which is recently published by Lv et al. (J Cardiothorac Surg 16(1):146, 2021). In this article, Lv et al. conclude that plasma IL-6 is a potential biomarker for prediction of POD. However, we note several issues in this study that would have made interpretation of their results questionable. Our main concerns include the use of a short POD assessment time, no providing the data of analgesics and sedatives used in the ICU, application of incorrect statistical methods when assessing predictive ability of plasma IL-6 for the development of POD, and incorrect interpretation for the area under the receiver operating characteristic curve. We believe that addressing these issues will improve the transparency of this study and help the interpretation of findings.

[Perioperative management of ortho-geriatric knee or hip arthroplasty patients]

Due to the changing age structure of the Western population, an increase in geriatric patients in endoprosthetic care of hip and knee joints is to be expected in the future. The age-related frailty and the existing comorbidities pose great challenges for the entire treatment team. In the preoperative phase, geriatric patients should be identified as such and adjustable risk factors should be addressed prior to surgery. The primary goals of treatment are to minimize trauma from anesthesia and endoprosthetic surgery to ensure immediate postoperative mobilization of patients. At the same time, any perioperative complications, especially intensive care treatments, should be prevented. This is achieved excellently with algorithms that are well known from fast-track surgery.

Incidence of and Risk Factors for Emergence Delirium and Postoperative Delirium in Neurosurgical Patients- A Prospective Cohort Study

Background

Delirium after surgery is a spectrum of clinical syndrome constituting emergence delirium (ED) and/or postoperative delirium (POD).

Objectives

The primary objective of this study was to evaluate the incidence of ED and POD in patients after neurosurgical procedures. The secondary objectives were to examine the relationship between ED and POD and identify perioperative risk factors of ED and POD.

Materials and Methods

This is a prospective cohort study conducted at the National Institute of Mental Health and Neurosciences. After obtaining the ethics committee approval, consecutive adult patients scheduled for elective neurosurgical procedures from February 2018 to November 2018 were included. We excluded children, patients with preoperative Glasgow Coma score <15, and patients with preoperative delirium. ED was assessed using Riker's Sedation-Agitation Score and POD was assessed using Confusion Assessment Method. Data collection included patient demographics, details of anesthetics and analgesics, and neurosurgical details.

Results

The incidence of ED and POD was 41% (N = 82/200) and 20% (N = 40/200), respectively. The occurrence of ED and POD coexisting as a continuous spectrum was 15%. Patients undergoing spine surgeries were found to have 44% less risk of ED than after cranial surgeries (P = 0.032). Presence of ED was associated with 1.8 times higher risk of POD (P < 0.001) and male gender was associated with 2.5 times higher risk of POD (P = 0.005).

Conclusions

Incidences of ED and POD are higher after neurosurgery as compared with that reported in nonneurosurgical population previously.

Development and validation of a delirium risk prediction preoperative model for cardiac surgery patients (DELIPRECAS): An observational multicentre study

STUDY OBJECTIVE

To develop and validate a delirium risk prediction preoperative model for patients undergoing cardiac surgery.

DESIGN

Observational prospective multicentre study.

SETTING

Six intensive care units in Spain.

PATIENTS

689 patients undergoing cardiac surgery consecutively, aged ≥18 years.

MEASUREMENTS

The primary outcome measure was the development of delirium, diagnosed using the Confusion Assessment Method in Intensive Care Units (CAM-ICU), during the stay in the intensive care unit after cardiac surgery.

MAIN RESULTS

The model was developed with 345 consecutive patients undergoing cardiac surgery at six hospitals and validated with another 344 patients from the same hospitals. The prediction model contained four preoperative risk factors: age over 65 years, Mini-Mental State Examination (MMSE) score of 25-26 points (possible impairment of cognitive function) or < 25 (impairment of cognitive function), insomnia needing medical treatment and low physical activity (walk less than 30 min a day). The model had an area under the receiver operating characteristics curve of 0.825 (95% confidence interval: 0.76-0.89). The validation resulted in an area under the curve of 0.79 (0.73-0.85) and the pooled area under the receiver operating characteristics curve (n = 689) was 0.81 (0.76-0.85). We stratified patients in groups of low (0%-20%), moderate (> 20%-40%), high (> 40%-60%) and very high (> 60%) risk of developing delirium, with a positive and negative predictive value for the very high risk group of 70.97% and 85.56%, respectively.

CONCLUSION

The DELIPRECAS model (DELIrium PREvention CArdiac Surgery), consisting of four well-defined clinical risk factors, can predict in the preoperative period the risk of developing postoperative delirium in patients undergoing cardiac surgery. An automatic version of the risk calculator is available.

Effectiveness and harms of pharmacological interventions for the treatment of delirium in adults in intensive care units after cardiac surgery: a systematic review

OBJECTIVE

The objective of this review was to synthesize the best available evidence on the effectiveness and harms of pharmacological interventions for the treatment of delirium in adult patients in the intensive care unit (ICU) after cardiac surgery.

INTRODUCTION

Patients who undergo cardiac surgery are at high risk of delirium (incidence: 50-90%). Delirium has deleterious effects, increasing the risk of death and adversely affecting recovery. Clinical interventional trials have been conducted to prevent and treat postoperative delirium pharmacologically including antipsychotics and sedatives. These trials have provided some evidence about efficacy and influenced clinical decision making. However, much reporting is incomplete and provides biased assessments of efficacy; benefits are emphasized while harms are inadequately reported.

INCLUSION CRITERIA

Participants were ≥ 16 years, any sex or ethnicity, who were treated postoperatively in a cardiothoracic ICU following cardiac surgery and were identified as having delirium. Any pharmacological intervention for the treatment of delirium was included, regardless of drug classification, dosage, intensity or frequency of administration. Outcomes of interest of this review were: mortality, duration and severity of delirium, use of physical restraints, quality of life, family members' satisfaction with delirium management, duration/severity of the aggressive episode, associated falls, severity of accidental self-harm, pharmacological harms, harms related to over-sedation, ICU length of stay, hospital length of stay (post ICU), total hospital length of stay, need for additional intervention medication and need for rescue medication. Randomized controlled trials were considered first and in their absence, non-randomized controlled trials and quasi-experimental would have been considered, followed by analytical observational studies.

METHODS

A search was conducted in PubMed, Embase, CINAHL, Web of Science, Cochrane Central Register of Controlled Trials, Scopus, Epistemonikos, Australian New Zealand Clinical Trials Registry, ClinicalTrials.gov, Clinical Trials in New Zealand, and ProQuest Dissertations and Theses to locate both published and unpublished studies. There was no date limit for the search. A hand search for primary studies published between January 1, 2012 and November 17, 2018 in relevant journals was also conducted. Only studies published in English were considered for inclusion. Two reviewers independently assessed the methodological quality using standardized critical appraisal instruments from JBI and McMaster University. Quantitative data were extracted using the standardized JBI data extraction tool. A meta-analysis was not performed, as there was too much clinical and methodological heterogeneity in the included studies. Results have been presented in a narrative form. Standard GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) evidence assessment of outcomes has been reported.

RESULTS

Three RCTs investigating morphine versus haloperidol (n = 53), ondansetron versus haloperidol (n = 72), and dexmedetomidine versus midazolam (n = 80) were included. Due to heterogeneity and incomplete reporting, a meta-analysis was not feasible. Overall, the methodological quality of these studies was found to be low. Additionally, this review found reporting of harms to be inadequate and superficial for all three studies and did not meet the required standards for harms reporting, as defined by the CONSORT statement extension for harms.

CONCLUSIONS

It was not possible to draw any valid conclusions regarding the effectiveness of morphine vs haloperidol, ondansetron vs haloperidol or dexmedetomidine vs midazolam in treating delirium after cardiac surgery. This is due to the low number of studies, the poor methodological quality in conducting and reporting and the heterogeneity between the studies.

Risk factors for postoperative delirium in patients with triple-branched stent graft implantation

Background

Neurological complications is a common complication following novel triple-branched stent graft implantation in patients with Stanford type A aortic dissection (AAD). But the incidence and risk factors of postoperative delirium (POD) are not completely clear. The aim of this study was to investigate the incidence and risk factors of POD after novel triple-branched stent graft implantation.

Methods

An observational study of AAD patients who underwent novel triple-branched stent graft implantation between January 2017 and July 2019 were followed up after surgery. Patients’ delirium was screened by the Richmond Agitation-Sedation Scale and the Confusion Assessment Method for the intensive care unit from the first day after the operation, lasted 5 days. The risk factors of POD were analyzed by the Cox proportional hazard models.

Results

A total of 280 AAD patients were enrolled in this research, the incidence of POD was 37.86%. Adjusting for age, body mass index, and mechanical ventilation duration, multivariate Cox regression analysis model revealed that non-manual work (adjusted hazard ratio [AHR] = .554; 95% CI: 0.335–0.915; P = .021), Acute Physiology and Chronic Health Evaluation II (APACHE-II) scores > 20 (AHR = 3.359, 95% CI: 1.707–6.609, P < .001), hypoxemia (AHR = 1.846, 95% CI: 1.118–3.048, P = .017), and more than two types of analgesics and sedatives were independently associated with POD.

Conclusions

This study showed that risk factors independently associated with POD were APACHE-II score > 20, hypoxemia, and more types of analgesics and sedatives, and non-manual work was the protective factor.

Trial registration

This study was retrospectively registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR1900022408; Date: 2019/4/10).

Complications of Thoracolumbar Adult Spinal Deformity Surgery

Adult spinal deformity (ASD) is a challenging problem for spine surgeons given the high risk of complications, both medical and surgical. Surgeons should have a high index of suspicion for medical complications, including cardiac, pulmonary, thromboembolic, genitourinary and gastrointestinal, renal, cognitive and psychiatric, and skin conditions, in the perioperative period and have a low threshold for involving specialists. Surgical complications, including neurologic injuries, vascular injuries, proximal junctional kyphosis, durotomy, and pseudarthrosis and rod fracture, can be devastating for the patient and costly to the health-care system. Mortality rates have been reported to be between 1.0% and 3.5% following ASD surgery. With the increasing rate of ASD surgery, surgeons should properly counsel patients about these risks and have a high index of suspicion for complications in the perioperative period.

Power Spectrum and Cross Power Spectral Density Based EEG Correlates of Intensive Care Delirium

Full montage EEG recordings of 15 ICU patients (altogether 23 recordings) were analysed to find EEG correlates of delirium. CAM-ICU assessment results were used as the reference. Time period from 7 to 30 minutes at the beginning of the recordings was analysed in 10 sec segments with 5 sec overlap. Relative power in the conventional frequency bands of the EEG signal at 20 electrode locations with common reference was calculated. In the state of delirium the relative power of frequencies above 8 Hz was lower; this effect was predominantly observed at central and parietal lobes. Also, the absolute cross power spectral density of 20 - 30 Hz was significantly lower in delirium between almost any two electrode locations.

Predisposing and Precipitating Factors Associated With Postoperative Delirium in Patients Undergoing Cardiac Surgery at a Veterans Affairs Medical Center: A Pilot Retrospective Analysis

OBJECTIVE

Patients treated at Veterans Affairs (VA) medical centers are in poorer health, experience more medical and psychiatric conditions, and make greater use of medical resources than do patients in the general population. In the present pilot study, the authors examined their recent experience at a VA medical center to determine the incidence and risk factors associated with the development of postoperative delirium in VA patients after cardiac surgery and hypothesized that the risk factors for postoperative delirium after cardiac surgery are different between VA and non-VA patients.

DESIGN

Retrospective cohort study.

SETTING

Clement J. Zablocki Veterans Affairs Medical Center.

PARTICIPANTS

The study comprised 250 consecutive patients undergoing cardiac surgery from July 2014 to March 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographics, coexisting diseases, and medications were obtained from the VA electronic medical record. The European System for Cardiac Operative Evaluation II mortality risk index was calculated for each patient. The type and duration of the procedure and the duration of bypass were recorded. Intraoperative crystalloid, colloid, cell saver, and blood product volumes were compiled. Progress notes and International Classification of Diseases, Tenth Revision, Clinical Modification codes were searched for documentation of postoperative delirium. Thirty-eight patients (15.2%) developed postoperative delirium. Stepwise logistic regression analysis demonstrated that the European System for Cardiac Operative Evaluation II mortality risk index (odds ratio [OR] 1.036, 95% confidence interval [CI] [1.003-1.070]; p = 0.0344), congestive heart failure (OR 2.223 [95% CI 1.046-4.722]; p = 0.0377), pre-existing cognitive impairment (OR 5.147 [95% CI 1.994-13.28]; p = 0.0007), and the presence of a neuropsychiatric disorder (OR 2.015 [95% CI 1.004-4.043]; p = 0.0487) were predisposing factors associated with higher odds of postoperative delirium. The duration of surgery; transfusion of blood products (including packed red blood cells, fresh frozen plasma, and platelets); the durations of mechanical ventilation and conscious sedation (using either propofol or dexmedetomidine); and the length of intensive care unit stay were precipitating factors associated with higher odds of postoperative delirium.

CONCLUSIONS

The results demonstrate that congestive heart failure, pre-existing cognitive impairment, and the presence of a neuropsychiatric disorder are predisposing risk factors for postoperative delirium after cardiac surgery in VA patients, whereas the duration of surgery, transfusion of blood products, durations of mechanical ventilation and conscious sedation, and length of intensive care unit stay are precipitating factors for postoperative delirium. These findings in VA patients generally are similar to those observed in the civilian population despite the differences between these cohorts.

Intra-aortic balloon pump does not influence cerebral hemodynamics and neurological outcomes in high-risk cardiac patients undergoing cardiac surgery: an analysis of the IABCS trial

Background

The intra-aortic balloon pump (IABP) is often used in high-risk patients undergoing cardiac surgery to improve coronary perfusion and decrease afterload. The effects of the IABP on cerebral hemodynamics are unknown. We therefore assessed the effect of the IABP on cerebral hemodynamics and on neurological complications in patients undergoing cardiac surgery who were randomized to receive or not receive preoperative IABP in the ‘Intra-aortic Balloon Counterpulsation in Patients Undergoing Cardiac Surgery’ (IABCS) trial.

Methods

This is a prospectively planned analysis of the previously published IABCS trial. Patients undergoing elective coronary artery bypass surgery with ventricular ejection fraction ≤ 40% or EuroSCORE ≥ 6 received preoperative IABP (n = 90) or no IABP (n = 91). Cerebral blood flow velocity (CBFV) of the middle cerebral artery through transcranial Doppler and blood pressure through Finometer or intra-arterial line were recorded preoperatively (T1) and 24 h (T2) and 7 days after surgery (T3) in patients with preoperative IABP (n = 34) and without IABP (n = 33). Cerebral autoregulation was assessed by the autoregulation index that was estimated from the CBFV response to a step change in blood pressure derived by transfer function analysis. Delirium, stroke and cognitive decline 6 months after surgery were recorded.

Results

There were no differences between the IABP and control patients in the autoregulation index (T1: 5.5 ± 1.9 vs. 5.7 ± 1.7; T2: 4.0 ± 1.9 vs. 4.1 ± 1.6; T3: 5.7 ± 2.0 vs. 5.7 ± 1.6, p = 0.97) or CBFV (T1: 57.3 ± 19.4 vs. 59.3 ± 11.8; T2: 74.0 ± 21.6 vs. 74.7 ± 17.5; T3: 71.1 ± 21.3 vs. 68.1 ± 15.1 cm/s; p = 0.952) at all time points. Groups were not different regarding postoperative rates of delirium (26.5% vs. 24.2%, p = 0.83), stroke (3.0% vs. 2.9%, p = 1.00) or cognitive decline through analysis of the Mini-Mental State Examination (16.7% vs. 40.7%; p = 0.07) and Montreal Cognitive Assessment (79.16% vs. 81.5%; p = 1.00).

Conclusions

The preoperative use of the IABP in high-risk patients undergoing cardiac surgery did not affect cerebral hemodynamics and was not associated with a higher incidence of neurological complications.

Trial registrationhttp://www.clinicaltrials.gov (NCT02143544).

The relationship between serum cobalamin, folic acid, and homocysteine and the risk of post-cardiac surgery delirium

Purpose: It has been reported that cobalamin and folate deficiency is related to delirium in persons with dementia. We evaluated the association of admission serum levels of cobalamin, folic acid, and homocysteine with the occurrence of acute delirium after coronary artery bypass surgery. Methods: In this prospective cohort study, serum levels of cobalamin, folic acid, and homocysteine were measured for 296 patients upon admission. Delirium was defined by the confusion assessment method for the intensive care unit. Results: Postoperative delirium was detected in 23% (n=68) of patients. Cobalamin deficiency, folate deficiency, and hyperhomocysteinemia were observed in 29% (n=86), 6% (n=18), and 68% (n=200) of patients, respectively. The mean ± SD serum levels of folic acid were 10.77±5.39 ng/mL and 12.86±6.51 ng/mL in delirium and non-delirium patients, respectively (P=0.008). The median (interquartile range [IQR]) serum levels of cobalamin were 280 (216-351) and 247 (195.5-336) in delirium and non-delirium patients, respectively (P=0.09). The median (IQR) serum levels of homocysteine were 18.5 (14.5-22.1) µmol/L and 17.33 (14.2-23.2) µmol/L in delirium and non-delirium patients, respectively (P=0.94). Multivariate regression analysis adjusted by other risk factors indicated that serum homocysteine, folate, and cobalamin levels had no association with the occurrence of delirium. Conclusion: There was no relationship between the preoperative levels of cobalamin, folate, and homocysteine, and acute occurrence of delirium observed after cardiac surgery.

Preventive Effect of Suvorexant for Postoperative Delirium after Coronary Artery Bypass Grafting

OBJECTIVE

Suvorexant is an orexin receptor antagonist and is effective in inducing sleep. We hypothesized that Suvorexant would reduce the incidence of postoperative delirium (POD) after coronary artery bypass grafting (CABG).

METHODS

We reviewed 88 patients (12 women, mean age: 69.3 ± 2.5 years) who were undergone CABG alone. Patients were divided into two groups; patients received Suvorexant (S group, n = 36), patients not received Suvorexant (N group, n = 52), and the following data were analyzed and compared between two groups.

RESULTS

Intensive Care Unit Delirium Screening Checklist Score was significantly lower in S group compared with N group (N:S = 2.0 ± 1.7:0.8 ± 1.0, p = 0.0003). Although POD was present in 11 of 52 patients (21.2%) in N group, one patient (2.8%) developed in S group (p = 0.008). In S group, both intensive care unit stay (N:S = median 6:5 days, p = 0.001) and hospital stay (N:S = median 23:20 days, p = 0.035) were significantly shorter than in N group.

CONCLUSIONS

Suvorexant might reduce incidence of POD in patients undergone CABG.

Incidence and risk factors of subsyndromal delirium after curative resection of gastric cancer

Background

Subsyndromal delirium, a condition in which patients exhibit some, but not all, of the symptoms of delirium, can negatively affect the outcomes of patients with cancer. However, the incidence of subsyndromal delirium in patients with gastric cancer is unknown. Here, we investigated the incidence and risk factors of subsyndromal delirium after curative resection of gastric cancer.

Methods

We recruited consecutive patients with gastric cancer who were scheduled for curative resection at a tertiary hospital. Patients’ subsyndromal delirium symptoms were serially assessed preoperatively and 1, 2, 3, and 7 days postoperatively using the Delirium Rating Scale-Revised-98 (DRS-R-98). A DRS-R-98 score of 8–14 at any postoperative assessment was considered to indicate subsyndromal delirium. Sociodemographic and pre−/intra-operative clinical data were also assessed. Logistic regression analyses were used to determine the associated risk factors.

Results

Data were analysed from 163 out of 217 eligible patients. Postoperative delirium occurred in one patient (0.6%) and subsyndromal delirium occurred in 19 patients (11.7%). Age ≥ 70 years (odds ratio, [OR] 3.85; 95% confidence interval [CI], 1.36–10.92; p = 0.011) and education level ≤ 9 years (OR, 3.98; 95% CI, 1.39–11.41; p = 0.010) were independent risk factors of subsyndromal delirium after adjusting for preoperative cognitive function. Other pre−/intra-operative variables including anxiety/depression, poor sleep quality, and anaesthesia duration were not associated with subsyndromal delirium.

Conclusions

In contrast to the low incidence of delirium among patients undergoing curative resection of gastric cancer, a substantial proportion of such patients experienced subsyndromal delirium. Considering the prognostic implications, more careful detection and management of subsyndromal delirium may be warranted in patients with gastric cancer.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4681-2) contains supplementary material, which is available to authorized users.

Incidence and risk factors of postoperative delirium in the elderly patients with hip fracture

Background

To investigate the incidence and related risk factors of delirium in elderly patients with hip fracture.

Methods

This is a retrospective study, performed in a medical center from October 2014 to February 2017, which enrolled all subjects aged over 65 years who were admitted for hip surgeries (hip arthroplasty, proximal femoral nail fixation). Univariate and multivariate logistic analysis was used to determine the incidence and risk factors of delirium. Delirium was assessed according to the Confusion Assessment Method (CAM).

Results

Overall, 19.29% of total 306 patients (mean age 81.9 ± 5.4 years) were identified as delirium. The delirium was significantly associated (p < 0.05) with the factors of age, hospitalization, diabetes, preoperative hematocrit (HCT), perioperative protein consumption, transfusion volume, preoperative leukocyte level, albumin level, American Society of Anesthesiologists (NYHA) classification, American Society of Anesthesiologists (ASA) classification, blood loss, coronary heart disease, and cerebral infarction. Multivariate analysis of the variables confirmed that age (> 75 years old), diabetes, and ASA classification (> 2 level) are the independent risk factors of postoperative delirium (POD). In addition, patients in delirium had prolonged hospitalization and high perioperative albumin infusion.

Conclusion

The elderly patients over the age of 75 years with the history of diabetes or ASA classification > 2 level were at higher risk of POD. Delirium is an important postoperative complication, which had prolonged hospitalization and high perioperative albumin infusion.

Level of evidence: III

Effectiveness and harms of pharmacological interventions in the treatment of delirium in adults in intensive care units post cardiac surgery: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The review objective is to synthesize the best available evidence on the effectiveness and harms of pharmacological interventions in the treatment of delirium in adults in intensive care units (ICU) after cardiac surgery.The specific review question is: What is the effectiveness and what are the harms of pharmacological interventions in relation to the duration and severity of delirium episodes, length of stay in ICU, length of stay in hospital, functional capacity and quality of life and mortality for critically ill adult patients treated in intensive care after cardiac surgery?

A Proactive Approach to High Risk Delirium Patients Undergoing Total Joint Arthroplasty

BACKGROUND

Delirium is a common complication among elderly patients undergoing total joint arthroplasty (TJA). Its incidence has been reported from 4% to 53%. The Centers for Medicare and Medicaid Services consider delirium following TJA a "never-event." The purpose of this study is to evaluate a simple perioperative protocol used to identify delirium risk patients and prevent its incidence following TJA.

METHODS

Our group developed a protocol to identify and prevent delirium in patients undergoing TJA. All patients were screened and scored in the preoperative assessment, on criteria such as age, history of forgetfulness, history of agitation or visual hallucinations, history of falls, history of postoperative confusion, and inability to perform higher brain functions. Patients were scored on performance in a simple mental examination. The patients were classified as low, medium, or high risk. Patients who were identified as high risk were enrolled in a delirium avoidance protocol that minimized narcotics and emphasized nursing involvement and fluids administration.

RESULTS

Five of 7659 (0.065%) consecutive TJA patients from 2010 to 2015 developed delirium. A total of 422 patients were identified as high risk. All 5 patients who suffered delirium were within the high risk group. No low or medium risk patients suffered a delirium complication. Three (0.039%) patients suffered drug-induced delirium, 1 (0.013%) had delirium related to alcohol withdrawal, and 1 (0.013%) had delirium after a systemic infection.

CONCLUSION

This protocol is effective in identifying patients at high delirium risk and diminishing the incidence of this complication by utilizing a simple screening tool and perioperative protocol.

Cerebral hemodynamics with intra-aortic balloon pump: business as usual?

OBJECTIVE

Intra-aortic balloon pump (IABP) is commonly used as mechanical support after cardiac surgery or cardiac shock. Although its benefits for cardiac function have been well documented, its effects on cerebral circulation are still controversial. We hypothesized that transfer function analysis (TFA) and continuous estimates of dynamic cerebral autoregulation (CA) provide consistent results in the assessment of cerebral autoregulation in patients with IABP.

APPROACH

Continuous recordings of blood pressure (BP, intra-arterial line), end-tidal CO₂, heart rate and cerebral blood flow velocity (CBFV, transcranial Doppler) were obtained (i) 5 min with IABP ratio 1:3, (ii) 5 min, starting 1 min with the IABP-ON, and continuing for another 4 min without pump assistance (IABP-OFF). Autoregulation index (ARI) was estimated from the CBFV response to a step change in BP derived by TFA and as a function of time using an autoregressive moving-average model during removal of the device (ARI _t ). Critical closing pressure and resistance area-product were also obtained.

MAIN RESULTS

ARI with IABP-ON (4.3  ±  1.2) were not different from corresponding values at IABP-OFF (4.7  ±  1.4, p  =  0.42). Removal of the balloon had no effect on ARI _t , CBFV, BP, cerebral critical closing pressure or resistance area-product.

SIGNIFICANCE

IABP does not disturb cerebral hemodynamics. TFA and continuous estimates of dynamic CA can be used to assess cerebral hemodynamics in patients with IABP. These findings have important implications for the design of studies of critically ill patients requiring the use of different invasive support devices.

The Effect of Treatment of Anemia with Blood Transfusion on Delirium: A Systematic Review

OBJECTIVES

Treating the precipitating factors of delirium is the mainstay of the prevention and treatment of delirium. We aim to investigate the role of anemia and blood transfusion within the multicomponent prevention and treatment strategy of delirium.

DESIGN

Systematic review.

SETTING

We included cohort studies or Randomized Controlled Trials (RCTs) that considered blood transfusion as treatment for delirium or risk factor, and had delirium as outcome.

PARTICIPANTS

Hospitalized patients above 55 years old.

MEASUREMENTS

We searched MEDLINE from 1946 through November 2014. Quality assessment and data extraction were performed systematically.

RESULTS

We included 23 studies (n = 29,471). The majority of the studies (n = 22) had a limited quality and for one study quality was uncertain. Two studies evaluated the association between transfusion strategy and postoperative delirium and found no association. Twenty-one studies investigated blood transfusion as a risk factor for delirium. In four of the 21 studies it could be assumed that delirium occurred after transfusion. One of these studies stated that transfusion was a significant risk factor for subsequent delirium (odds ratio (OR) = 3.68, 95% confidence interval (CI) = 1.32-10.94). The other three studies found no association between transfusion and delirium. In the remaining 17 studies, it was not clear whether delirium occurred before or after transfusion, so no conclusion could be drawn on the role of transfusion in delirium development.

CONCLUSION

The majority of the included studies was not suited to answer the research question properly as the time course of the beginning of delirium as to transfusion was lacking. Our review shows that there is no good quality evidence available for blood transfusion to be a risk factor for delirium or to be a preventive or treatment option.

Incidence and Risk Factors of Delirium in Patients After Type-A Aortic Dissection Surgery

OBJECTIVE

To study the incidence and related risk factors for postoperative delirium after type-A aortic dissection in patients who underwent Sun's procedure (total arch replacement using a tetrafurcate graft with stented elephant trunk implantation).

DESIGN

A retrospective study.

SETTING

A cardiac surgical intensive care unit.

PARTICIPANTS

The study comprised 100 patients admitted to the intensive care unit for type-A aortic dissection.

INTERVENTIONS

All patients underwent Sun's procedure with uniform preoperative and anesthetic treatment.

MEASUREMENTS AND MAIN RESULTS

Delirium was evaluated using the Confusion Assessment Method for the intensive care unit. Baseline demographics and preoperative, intraoperative, and postoperative data were recorded and analyzed retrospectively via univariate analysis and multivariate logistic regression. The incidence of postoperative delirium was 34%, according to Confusion Assessment Method for the intensive care unit criteria. Univariate analysis revealed that 17 variables differed significantly among patients with and without delirium. Additional multivariate stepwise logistic regression analysis confirmed that cerebrovascular disease history, surgery duration, cardiopulmonary bypass duration, intubation time, and hypoxia were strongly associated with postoperative delirium.

CONCLUSIONS

Delirium is a common postoperative complication of aortic dissection. Cerebrovascular disease history, surgery and cardiopulmonary bypass duration, postoperative hypoxia, and intubation time are independently associated with the development of delirium. Early diagnosis of delirium and modifying these factors properly may be helpful to improve patients' prognosis.

The Effects of Blood Transfusion on Delirium Incidence

BACKGROUND

Both anemia and blood transfusion could be precipitating factors for delirium; hence in postoperative patients with anemia at high risk for delirium, it is controversial whether transfusion is the best option. The aim of this study is to investigate the association of anemia and delirium and the role of blood transfusion within the multicomponent prevention strategy of delirium.

METHODS

We conducted a substudy of a multicenter randomized controlled trial. Four hundred fifteen patients aged 65 to 102 years old admitted for hip fracture surgery were enrolled. Delirium was assessed daily using criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Data on hemoglobin values and transfusion were collected from the electronic medical records.

RESULTS

One hundred fifteen (32.5%) patients experienced delirium during hospitalization, 238 (57.5%) had a hemoglobin level ≤ 6.0 mmol/L (9.7 g/dL) at any time during hospitalization, and 140 (33.7%) received a blood transfusion. Anemia (a hemoglobin level ≤ 6.0 mmol/L [9.7 g/dL]) was associated with delirium (odds ratio, 1.81; 95% confidence interval, 1.15-2.86). Blood transfusion was a protective factor for delirium in patients with the lowest measured hemoglobin level ≤ 6.0 mmol/L (9.7 g/dL) (odds ratio, 0.26; 95% confidence interval, 0.10-0.70).

CONCLUSION

Low hemoglobin level is associated with delirium, and receiving a blood transfusion is associated with a lower delirium incidence. It would be interesting to investigate the effect of blood transfusion as part of the multicomponent treatment of delirium in patients with anemia.

Predicting, preventing, and identifying delirium after cardiac surgery

Delirium after cardiac surgery is a major problem. The exact mechanisms behind delirium are not understood. Potential pathways of delirium include neurotransmitter interference, global cognitive disorder, and neuroinflammation. Several predisposing and precipitating risk factors have been identified for postoperative delirium. The development of delirium following cardiac surgery is associated with worse outcomes in the perioperative period. Multiple interventions are being explored for the prevention and treatment of delirium. Studies investigating the potential roles of biomarkers in delirium as well as pharmacological interventions to reduce the incidence and duration of delirium are necessary to mitigate this negative outcome.

Blood Pressure Deviations From Optimal Mean Arterial Pressure During Cardiac Surgery Measured With a Novel Monitor of Cerebral Blood Flow and Risk for Perioperative Delirium: A Pilot Study

OBJECTIVE

The aim of this study was to evaluate whether excursions of blood pressure from the optimal mean arterial pressure during and after cardiac surgery are associated with postoperative delirium identified using a structured examination.

DESIGN

Prospective, observational study.

SETTING

University hospital.

PARTICIPANTS

The study included 110 patients undergoing cardiac surgery.

INTERVENTIONS

Patients were monitored using ultrasound-tagged near-infrared spectroscopy to assess optimal mean arterial pressure by cerebral blood flow autoregulation monitoring during cardiopulmonary bypass and the first 3 hours in the intensive care unit.

MEASUREMENTS AND MAIN RESULTS

The patients were tested preoperatively and on postoperative days 1 to 3 with the Confusion Assessment Method or Confusion Assessment Method for the Intensive Care Unit, the Delirium Rating Scale-Revised-98, and the Mini Mental State Examination. Summative presence of delirium on postoperative days 1 through 3, as defined by the consensus panel following Diagnostic and Statistical Manual of Mental Disorders-IV-TR criteria, was the primary outcome. Delirium occurred in 47 (42.7%) patients. There were no differences in blood pressure excursions above and below optimal mean arterial pressure between patients with and without summative presence of delirium. Secondary analysis showed blood pressure excursions above the optimal mean arterial pressure to be higher in patients with delirium (mean±SD, 33.2±26.51 mmHgxh v 23.4±16.13 mmHgxh; p = 0.031) and positively correlated with the Delirium Rating Scale score on postoperative day 2 (r = 0.27, p = 0.011).

CONCLUSIONS

Summative presence of delirium was not associated with perioperative blood pressure excursions; but on secondary exploratory analysis, excursions above the optimal mean arterial pressure were associated with the incidence and severity of delirium on postoperative day 2.

Delirium after surgical and transcatheter aortic valve replacement is associated with increased mortality

OBJECTIVE

The purpose of this study was to determine the incidence and clinical significance of postoperative delirium (PD) in patients with aortic stenosis undergoing surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR).

METHOD

Between 2010 and 2013, 427 patients underwent TAVR (n = 168) or SAVR (n = 259) and were screened for PD using the Confusion Assessment Method for the Intensive Care Unit. The incidence of PD in both treatment groups was determined and its association with morbidity and mortality was retrospectively compared.

RESULTS

PD occurred in 135 patients (32%) with a similar incidence between SAVR (33% [86 out of 259]) and TAVR (29% [49 out of 168]) (P = .40). TAVR by transfemoral approach had the lowest incidence of PD compared with SAVR (18% vs 33%; P = .025) or TAVR when performed by alternative access techniques (18% vs 35%; P = .02). Delirium was associated with longer initial intensive care unit stay (70 vs 27 hours), intensive care unit readmission (10% [14 out of 135] vs 2% [6 out of 292]), and longer hospital stay (8 vs 6 days) (P < .001 for all). PD was associated with increased mortality at 30 days (7% vs 1%; P < .001) and 1 year (21% vs 8%; P < .001). After multivariable adjustment, PD remained associated with increased 1-year mortality (hazard ratio, 3.02; 95% confidence interval, 1.75-5.23; P < .001). There was no interaction between PD and aortic valve replacement approach with respect to 1-year mortality (P = .12). Among propensity-matched patients (n = 170), SAVR-treated patients had a higher incidence of PD than TAVR-treated patients (51% vs 29%; P = .004).

CONCLUSIONS

PD occurs commonly after SAVR and TAVR and is associated with increased morbidity and mortality. Given the high incidence of PD and its associated adverse outcomes, further studies are needed to minimize PD and potentially improve patient outcomes.

Relationship between cobalamin deficiency and delirium in elderly patients undergoing cardiac surgery

BACKGROUND

Delirium is common after cardiac surgery and is independently associated with increased morbidity, mortality, prolonged hospital stays, and higher costs. Cobalamin (vitamin B12) deficiency is a common cause of neuropsychiatric symptoms and affects up to 40% of elderly people. The relationship between cobalamin deficiency and the occurrence of delirium after cardiac surgery has not been examined in previous studies. We examined the relationship between cobalamin deficiency and delirium in elderly patients undergoing coronary artery bypass grafting (CABG) surgery.

MATERIAL AND METHODS

A total of 100 patients with cobalamin deficiency undergoing CABG were enrolled in this retrospective study. Control group comprised 100 patients without cobalamin deficiency undergoing CABG. Patients aged 65 years or over were included. Diagnosis of delirium was made using Intensive Care Delirium Screening Checklist. Delirium severity was measured using the Delirium Rating Scale-revised-98.

RESULTS

Patients with cobalamin deficiency had a significantly higher incidence of delirium (42% vs 26%; P=0.017) and higher delirium severity scores (16.5±2.9 vs 15.03±2.48; P=0.034) than patients without cobalamin deficiency. Cobalamin levels were significantly lower in patients with delirium than patients without delirium (P=0.004). Delirium severity score showed a moderate correlation with cobalamin levels (ρ=-0.27; P=0.024). Logistic regression analysis demonstrated that cobalamin deficiency was independently associated with postoperative delirium (OR 1.93, 95% CI 1.03-3.6, P=0.038).

CONCLUSION

The results of our study suggest that cobalamin deficiency may be associated with increased risk of delirium in patients undergoing CABG. In addition, we found that preoperative cobalamin levels were associated with the severity of delirium. This report highlights the importance of investigation for cobalamin deficiency in patients undergoing cardiac surgery, especially in the elderly.