Modifiable and nonmodifiable risk factors for postoperative delirium after cardiac surgery with cardiopulmonary bypass

Feasibility of Goal-Directed Fluid Therapy in Patients with Transcatheter Aortic Valve Replacement - An Ambispective Analysis

INTRODUCTION

Goal-directed fluid therapy (GDFT) has been shown to reduce postoperative complications. The feasibility of GDFT in transcatheter aortic valve replacement (TAVR) patients under general anesthesia has not yet been demonstrated. We examined whether GDFT could be applied in patients undergoing TAVR in general anesthesia and its impact on outcomes.

METHODS

Forty consecutive TAVR patients in the prospective intervention group with GDFT were compared to 40 retrospective TAVR patients without GDFT. Inclusion criteria were age ≥ 18 years, elective TAVR in general anesthesia, no participation in another interventional study. Exclusion criteria were lack of ability to consent study participation, pregnant or nursing patients, emergency procedures, preinterventional decubitus, tissue and/or extremity ischemia, peripheral arterial occlusive disease grade IV, atrial fibrillation or other severe heart rhythm disorder, necessity of usage of intra-aortic balloon pump. Stroke volume and stroke volume variation were determined with uncalibrated pulse contour analysis and optimized according to a predefined algorithm using 250 ml of hydroxyethyl starch.

RESULTS

Stroke volume could be increased by applying GDFT. The intervention group received more colloids and fewer crystalloids than control group. Total volume replacement did not differ. The incidence of overall complications as well as intensive care unit and hospital length of stay were comparable between both groups. GDFT was associated with a reduced incidence of delirium. Duration of anesthesia was shorter in the intervention group. Duration of the interventional procedure did not differ.

CONCLUSION

GDFT in the intervention group was associated with a reduced incidence of postinterventional delirium.

Impact of Limited Enhanced Recovery Pathway for Cardiac Surgery: A Single-Institution Experience

OBJECTIVES

Enhanced recovery pathway (ERP) refers to extensive multidisciplinary, evidence-based pathways used to facilitate recovery after surgery. The authors assessed the impact that limited ERP protocols had on outcomes in patients undergoing cardiac surgery at their institution.

DESIGN

A retrospective cohort study.

SETTING

This study was a single-institution study conducted at a university hospital.

PARTICIPANTS

Patients undergoing open adult cardiac surgery.

INTERVENTIONS

Enhanced recovery pathways limited to preoperative, intraoperative, and postoperative management of pain, atrial fibrillation prevention, and nutrition optimization were implemented.

MEASUREMENTS AND MAIN RESULTS

A total of 1,058 patients were included in this study. There were 374 patients in each pre- and post-ERP cohort after propensity matching, with no significant baseline differences between the 2 cohorts. Compared to the matched patients in the pre-ERP group, patients in the post-ERP group had decreased total ventilation hours (6.8 v 7.8, p = 0.006), less use of postoperative opioid analgesics as determined by total morphine milligram equivalent (32.5 v 47.5, p < 0.001), and a decreased rate of postoperative atrial fibrillation (23.3% v 30.5%, p = 0.032). Post-ERP patients also experienced less subjective pain and postoperative nausea and drowsiness as compared to their matched pre-ERP cohorts.

CONCLUSIONS

Limited ERP implementation resulted in significantly improved perioperative outcomes. Patients additionally experienced less postoperative pain despite decreased opioid use. Implementation of ERP, even in a limited format, is a promising approach to improving outcomes in patients undergoing cardiac surgery.

Functional intervention following cardiac surgery to prevent postoperative delirium in older patients (FEEL WELL study)

BACKGROUND

Postoperative delirium is a common complication in patients after cardiac surgery, especially in older patients, and can manifest as a disturbance of attention and consciousness. It can lead to increased postoperative morbidity, prolonged need for care, and mortality. The presented study investigates whether the occurrence of postoperative delirium after cardiac surgery can be prevented by a multisensory stimulation. It was conducted as a prospective, randomized, controlled, non-pharmacological intervention study in the years 2021 and 2022 at the University Hospital Bonn in Germany. A total of 186 patients over 65 years with elective cardiac surgery were enrolled. Patients were randomized either to the intervention or control group. In both groups, postoperative delirium was assessed with the 3-min diagnostic interview for confusion assessment method on the first 5 days after surgery and pain was assessed using the Numeric Rating Scale. Multisensory stimulation was performed 20 min a day for the first three postoperative days in the intervention group.

RESULTS

The incidence of postoperative delirium was 22.6% in the intervention group and 49.5% in the control group (p < 0.001). Duration of postoperative delirium was significantly shorter in the intervention group (p < 0.001). Stay in the intensive care unit was significantly longer in the control group (p = 0.006). In the regression model non-intervention, high pain scores, advanced age, and prolonged mechanical ventilation were associated with postoperative delirium (p = 0.007; p = 0.032; p = 0.006; p = 0.006, respectively).

CONCLUSIONS

Results of the study imply that a multisensory stimulation done on the first 3 days after planned cardiac surgery can reduce the incidence and duration of postoperative delirium in older patients. Influence of the treatment on the incidence of delirium in other patient groups, the length of stay in the intensive care unit, and patients´ postoperative pain should be confirmed in further clinical studies.

TRIAL REGISTRATION

DRKS, DRKS00026909. Registered 28 October 2021, Retrospectively registered, https://drks.de/search/de/trial/DRKS00026909 .

Delirium after Cardiac Surgery-A Narrative Review

Postoperative delirium (POD) after cardiac surgery is a well-known phenomenon which carries a higher risk of morbidity and mortality. Multiple patient-specific risk factors and pathophysiologic mechanisms have been identified and therapies have been proposed to mitigate risk of delirium development postoperatively. Notably, cardiac surgery frequently involves the use of an intraoperative cardiopulmonary bypass (CPB), which may contribute to the mechanisms responsible for POD. Despite our greater understanding of these causative factors, a substantial reduction in the incidence of POD remains high among cardiac surgical patients. Multiple therapeutic interventions have been implemented intraoperatively and postoperatively, many with conflicting results. This review article will highlight the incidence and impact of POD in cardiac surgical patients. It will describe some of the primary risk factors associated with POD, as well as anesthetic management and therapies postoperatively that may help to reduce delirium.

Postoperative infusion of dexmedetomidine via intravenous patient-controlled analgesia for prevention of postoperative delirium in elderly patients undergoing surgery

BACKGROUND

Postoperative delirium (POD) is a common clinical complication in elderly patients after surgery and predicts poor outcomes.

AIM

We researched whether postoperative infusion of dexmedetomidine (DEX) had prophylactic effect on POD in elderly patients.

METHODS

A total of 236 patients over the age of 60 years undergoing thoracoabdominal tumor surgery were enrolled in Zhejiang Cancer Hospital from November 2016 to October 2020. The patients were randomly assigned into DEX group (group D) and control group (Group C). DEX was provided via PCIA pump 1-3 days after surgery, which consisted of 3 ug/kg sufentanil and 3 ug/kg DEX in group D, and 3 ug/kg sufentanil without DEX in group C. The PCIA parameters were programmed as follows: total amount 150 ml, 2 ml bolus dose with a lock-out of 10 min and background infusion rate 2 ml/h. The primary endpoint was the incidence of POD, assessed twice daily within 7 days after surgery by Richmond Agitation-Sedation Scale (RASS) and the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). The secondary endpoint was postoperative hospitalization days, ICU stay time, adverse events and non-delirium complications.

RESULTS

The incidence of POD in all patients was 7%. The incidence of POD in group C was significantly higher than that in group D (10.1% vs 3.4%, P = 0.042). There were no significant differences in length of hospital stay after operation, ICU stay time, the percentage of patients discharged within 7 days after surgery, non-delirium complications, and 30-day all-cause deaths between the two groups. The incidence of hypertension in group D was lower than that in group C (P = 0.003), and there were no differences in other adverse events.

CONCLUSION

Patients aged over 60 years received DEX in addition to intravenous patient-controlled analgesia (PCIA) for major thoracoabdominal surgery experienced less delirium.

Balanced Nonopioid General Anesthesia With Lidocaine Is Associated With Lower Postoperative Complications Compared With Balanced Opioid General Anesthesia With Sufentanil for Cardiac Surgery With Cardiopulmonary Bypass: A Propensity Matched Cohort Study

BACKGROUND

There are no data on the effect of balanced nonopioid general anesthesia with lidocaine in cardiac surgery with cardiopulmonary bypass. The main study objective was to evaluate the association between nonopioid general balanced anesthesia and the postoperative complications in relation to opioid side effects.

METHODS

Patients undergoing cardiac surgery with cardiopulmonary bypass between 2019 and 2021 were identified. After exclusion of patients for heart transplantation, left ventricular assistance device, and off-pump surgery, we classified patients according to an opioid general balanced anesthesia or a nonopioid balanced anesthesia with lidocaine. The primary outcome was a collapsed composite of postoperative complications that comprise respiratory failure and confusion, whereas secondary outcomes were acute renal injury, pneumoniae, death, intensive care unit (ICU), and hospital length of stay.

RESULTS

We identified 859 patients exposed to opioid-balanced general anesthesia with lidocaine and 913 patients exposed to nonopioid-balanced general anesthesia. Propensity score matching yielded 772 individuals in each group with balanced baseline covariates. Two hundred thirty-six patients (30.5%) of the nonopioid-balanced general anesthesia versus 186 patients (24.1%) presented postoperative composite complications. The balanced lidocaine nonopioid general anesthesia group was associated with a lower proportion with the postoperative complication composite outcome OR, 0.72 (95% CI, 0.58-0.92; P = .027). The number of patients with acute renal injury, death, and hospital length of stay did not differ between the 2 groups.

CONCLUSIONS

A balanced nonopioid general anesthesia protocol with lidocaine was associated with lower odds of postoperative complication composite outcome based on respiratory failure and confusion.

The Relationship of Postoperative Pain and Opioid Consumption to Postoperative Delirium After Spine Surgery

Purpose

To examine the relationship between postoperative pain and opioid use and the development of postoperative delirium (POD), with attention to the preoperative opioid use status of patients.

Methods

This was a secondary analysis of data from a prospective observational study of patients (N = 219; ≥70 years old) scheduled to undergo elective spine surgery. Maximal daily pain scores (0-10) and postoperative morphine milligram equivalents per hour (MME/hr) were determined for postoperative days 1-3 (D1-3). POD was assessed by daily in-person interviews using the Confusion Assessment Method and chart review.

Results

Patients who reported regular preoperative opioid use (n = 58, 27%) reported significantly greater maximal daily pain scores, despite also requiring greater daily opioids (MME/hr) in the first 3 days after surgery. These patients were also more likely to develop POD. Interestingly, while postoperative pain scores were significantly higher in patients who developed POD, postoperative opioid consumption was not significantly higher in this group.

Conclusion

POD was associated with greater postoperative pain, but not with postoperative opioid consumption. While postoperative opioid consumption is often blamed for delirium, these findings suggest that uncontrolled pain may actually be a more important factor, particularly among patients who are opioid tolerant. These findings underscore the importance of employing multimodal perioperative analgesic management, especially among older patients who have a predilection to developing POD and baseline tolerance to opioids.

Predisposing and Precipitating Factors Associated With Delirium: A Systematic Review

IMPORTANCE

Despite discrete etiologies leading to delirium, it is treated as a common end point in hospital and in clinical trials, and delirium research may be hampered by the attempt to treat all instances of delirium similarly, leaving delirium management as an unmet need. An individualized approach based on unique patterns of delirium pathophysiology, as reflected in predisposing factors and precipitants, may be necessary, but there exists no accepted method of grouping delirium into distinct etiologic subgroups.

OBJECTIVE

To conduct a systematic review to identify potential predisposing and precipitating factors associated with delirium in adult patients agnostic to setting.

EVIDENCE REVIEW

A literature search was performed of PubMed, Embase, Web of Science, and PsycINFO from database inception to December 2021 using search Medical Subject Headings (MeSH) terms consciousness disorders, confusion, causality, and disease susceptibility, with constraints of cohort or case-control studies. Two reviewers selected studies that met the following criteria for inclusion: published in English, prospective cohort or case-control study, at least 50 participants, delirium assessment in person by a physician or trained research personnel using a reference standard, and results including a multivariable model to identify independent factors associated with delirium.

FINDINGS

A total of 315 studies were included with a mean (SD) Newcastle-Ottawa Scale score of 8.3 (0.8) out of 9. Across 101 144 patients (50 006 [50.0%] male and 49 766 [49.1%] female patients) represented (24 015 with delirium), studies reported 33 predisposing and 112 precipitating factors associated with delirium. There was a diversity of factors associated with delirium, with substantial physiological heterogeneity.

CONCLUSIONS AND RELEVANCE

In this systematic review, a comprehensive list of potential predisposing and precipitating factors associated with delirium was found across all clinical settings. These findings may be used to inform more precise study of delirium's heterogeneous pathophysiology and treatment.

Bispectral Index (BIS) Monitoring and Postoperative Delirium in Elderly Patients Undergoing Surgery: A Systematic Review and Meta-Analysis With Trial Sequential Analysis

OBJECTIVE

To examine the effect of bispectral index (BIS)-guided anesthesia on the incidence of postoperative delirium (POD) in elderly patients undergoing surgery.

DESIGN

A systematic review, meta-analysis, and trial sequential analysis (TSA).

SETTING

In the operating room, postoperative anesthesia care units (PACU), and ward.

PARTICIPANTS

Elderly patients (>60 years old) undergoing surgery.

INTERVENTIONS

The EMBASE, MEDLINE, and CENTRAL databases were searched systematically from their inception until December 2020 for randomized controlled trials comparing BIS and usual care or blinded BIS.

MEASUREMENTS AND MAIN RESULTS

Ten trials (N = 3,891) were included for quantitative meta-analysis. In comparison to the control group, there was no significant difference in the incidence of POD in elderly patients randomized to BIS-guided anesthesia (odds ratio [OR] 0.71, 95% CI 0.47-1.08, I² = 76%, p = 0.11, level of evidence = very low, TSA = inconclusive). The authors' review demonstrated that elderly patients with BIS-guided anesthesia were significantly associated with a lower incidence of postoperative cognitive dysfunction (POCD) (OR 0.64, 95% CI 0.46-0.88, p = 0.006), extubation time (mean difference [MD] -3.38 minutes, 95% CI -4.38 to -2.39, p < 0.00001), time to eye opening (MD -2.17 minutes, 95% CI -4.21 to -0.14, p = 0.04), and time to discharge from the PACU (MD -10.77 minutes, 95% CI -11.31 to - 10.23, p < 0.00001).

CONCLUSION

The authors' meta-analysis demonstrated that BIS-guided anesthesia was not associated with a reduced incidence of POD, but it was associated with a reduced incidence of POCD and improved recovery parameters.

Peripheral inflammatory markers during an acute bacterial infection in older patients with and without cognitive dysfunction: A case control study

Dementia is a known risk factor for acute bacterial infections which may also play a significant role in promoting or accelerating cognitive impairment. Pneumonia and urinary tract infections are the main cause of hospitalisation of dementia patients and infections are a major precipitant of delirium. It is well established that peripheral immune signals induce a neuroinflammatory response largely mediated by microglial cells which is amplified with advanced age, neurodegenerative disorders and genetic characteristics. Reversely, the innate immune response to acute bacterial infection is tightly regulated by the brain. It remains unclear whether dysfunctional neural circuits affected by dementia and/or delirium could alter systemic innate immune responses at the periphery. The current study aims to determine if dementia and/or delirium are associated with an altered systemic inflammatory response to an acute bacterial infection. We recruited 46 hospitalised older patients with acute bacterial infections. From these, 29 participants had cognitive dysfunction (6 with delirium, 12 with dementia and 11 with delirium superimposed on dementia) and 17 had normal cognition. We also included a control group of 11 patients with dementia but with no current infection matched for age and educational status. Baseline characteristics were tested between groups using Kruskal-Wallis test and pairwise comparisons were subsequently assessed with Bonferroni correction for multiple comparisons for continuous variables. Chi square test was used to assess differences between groups in categorical data and correlations between peripheral inflammatory parameters were assessed with Spearman's test. The 4 groups with infection and the control group with no infection had similar characteristics except for cognitive function and functionality which was higher for the group of infected cognitively healthy participants. Levels of C-reactive protein were similar between the infected groups and higher than the non-infected dementia group. Infected patients with cognitive dysfunction (delirium and/or dementia) had higher serum levels of IL-6, TNF-alpha and IL-1beta. These participants had reduced expression of miR-145 in circulating exosomes which correlated negatively with miR-155 levels (r = −0.411, p = 0.027). Expression of CR1 in circulating CD14⁺ monocytes was higher in infected participants with cognitive dysfunction and, in this group, PICALM correlated both with TNF-alpha and IL-6. In contrast to what was observed in participants with normal cognition, expression of CR1 did not correlate with DAP12 in infected participants with cognitive dysfunction. Taken together, our findings suggest that cognitive dysfunction is associated with an exaggerated proinflammatory response during acute bacterial infection with deregulation of several molecular signalling pathways in circulating exosomes and in monocytes.

Dexmedetomidine Use in Intensive Care Unit Sedation and Postoperative Recovery in Elderly Patients Post-Cardiac Surgery (DIRECT)

OBJECTIVE

This study examined recovery, delirium, and neurocognitive outcome in elderly patients receiving dexmedetomidine or propofol sedation after undergoing cardiac surgery.

DESIGN

Open-label randomized trial.

SETTING

Single center.

PARTICIPANTS

A total of 70 patients older than 75 years without English language limitations and Mini Mental State Examination scores >20.

INTERVENTIONS

Patients received either propofol (group P) or dexmedetomidine (group D) postoperatively until normothermic and hemodynamically stable.

MEASUREMENTS AND MAIN RESULTS

Quality of recovery (QoR) was measured by the QoR-40 questionnaire on postoperative day (POD) three. Secondary outcomes were incidence and duration of delirium, time to extubation, length of hospital stay, hospital mortality rate, postoperative quality of life (QoL; measured by SF-36 performed at baseline and six months postoperatively), and neurocognitive disorder (measured by Minnesota Cognitive Acuity Screen [MCAS] performed at baseline, POD5, and six months postoperatively). A total of sixty-seven patients completed the trial. There was no significant difference in QoR-40 scores (95% confidence interval [CI], -7.6081-to-10.9781; p = 1.000), incidence of delirium (group P, 42%; group D, 24%; p = 0.191), mean hospital stay (95% CI, -5.4838-to-1.5444; p = 0.297), mean time to extubation (95% CI, -19.2513-to-7.5561; p = 0.866), or mean duration of delirium (95% CI, -4.3065-to-1.067; p = 0.206) between groups. No patients died in the hospital. There were no significant differences in changes in SF-36 or MCAS scores over time between groups. There was a decline in MCAS score from preoperatively to POD5 in group P (95% CI, -8.95725-to- -2.61775; p = 0.0005), which was greater than that observed in group D.

CONCLUSIONS

The authors' findings demonstrated that the use of dexmedetomidine compared with propofol in elderly patients undergoing cardiac surgery was unlikely to improve QoR/postoperative QoL. Although the study was underpowered to detect secondary outcomes, the results suggested no reductions in delirium, time to extubation, and hospital stay, but a potential decrease in delayed neurocognitive recovery.

Postoperative Cardiovascular Surgery Delirium: Interrater Agreement Between Nurses and Clinical Nurse Specialist and Factors Associated With Prevalence

PURPOSE

The aims of this study were to examine interrater agreement of delirium between clinical nurses and a clinical nurse specialist, determine delirium subtype prevalence, and examine associated patient, procedure, and hospital factors.

DESIGN

A descriptive cross-sectional design and a convenience sample of nurses and patients on progressive care units were used in this study.

METHODS

Clinical nurse specialist data were collected on a case report form, and clinician and patient data were obtained from electronic databases. Interrater agreement of delirium prevalence was assessed by κ statistic, and logistic regression models were used to determine patient factors associated with delirium.

RESULTS

Of 216 patients, 23 had delirium; clinical nurses identified fewer cases than the clinical nurse specialist: 1.8% versus 10.7%; κ agreement, 0.27 (0.06, 0.49). By delirium subtype, hypoactive delirium was more frequent (n = 10). Factors associated with delirium were history of cerebrovascular disease (odds ratio [95% confidence interval], 2.8 [1.01-7.7]; P = .044), history of mitral valve disease (odds ratio [95% confidence interval], 0.31 [0.09-0.90]; P = .041), and longer perfusion time (odds ratio [95% confidence interval], 1.7 [1.1-2.7]; P = .016). One factor was associated with hypoactive delirium, longer perfusion time (odds ratio [95% confidence interval], 2.2 [1.3-4.2]; P = .008).

CONCLUSIONS

Because clinician-clinical nurse specialist delirium agreement was low and hypoactive delirium was common, clinical interventions are needed.

Delirium Prevention in Postcardiac Surgical Critical Care

This review provides an overview for health care teams involved in the perioperative care of cardiac surgery patients. The intention is to summarize key determinants of delirium, its impact on short- and long-term outcomes as well as to discuss effective management strategies. The first component of this review examines the prevalence and the factors associated with an increased risk of postoperative delirium. A multitude of predisposing (eg, baseline vulnerability and comorbidities) and precipitating (eg, type of cardiac surgery and postoperative care) factors that contribute to the occurrence of delirium are discussed.

Transcatheter versus Isolated Surgical Aortic Valve Replacement in Young High-Risk Patients: A Propensity Score-Matched Analysis

Background: Younger patients with severe symptomatic aortic stenosis are a particularly challenging collective with regard to the choice of intervention. High-risk patients younger than 75 years of age are often eligible for both the transcatheter aortic valve replacement (TAVR) and the isolated surgical aortic valve replacement (iSAVR). Data on the outcomes of both interventions in this set of patients are scarce. Methods: One hundred and forty-four propensity score-matched patients aged 75 years or less who underwent TAVR or iSAVR at the Hietzing Heart Center in Vienna, Austria, were included in the study. The mean age was 68.9 years (TAVR 68.7 vs. SAVR 67.6 years; p = 0.190) and the average EuroSCORE II was 5.4% (TAVR 4.3 [3.2%] vs. iSAVR 6.4 (4.3%); p = 0.194). Results: Postprocedural adverse event data showed higher rates of newly acquired atrial fibrillation (6.9% vs. 19.4%; p = 0.049), prolonged ventilation (2.8% vs. 25.0%; p < 0.001) and multi-organ failure (0% vs. 6.9%) in the surgical cohort. The in-hospital and 30-day mortality was significantly higher for iSAVR (1.4% vs. 13.9%; p = 0.012; 12.5% vs. 2.8%; p = 0.009, respectively). The long-term survival (median follow-up 5.0 years (2.2–14.1 years)) of patients treated with the surgical approach was superior to that of patients undergoing TAVR (p < 0.001). Conclusion: Although the survival analysis revealed a higher in-hospital and 30-day survival rate for high-risk patients aged ≤75 years who underwent TAVR, iSAVR was associated with a significantly higher long-term survival rate.

Prevention of postoperative delirium after cardiovascular surgery: A team-based approach

OBJECTIVE

We investigated the efficacy of the Delirium Team Approach program for delirium prevention after cardiovascular surgery.

METHODS

We retrospectively investigated 256 patients who underwent cardiac or thoracic vascular surgery between May 2017 and May 2020. We compared the outcomes before and after implementation of the Delirium Team Approach program in December 2018. The program included the following components: (a) educational sessions for the medical team regarding delirium and its management, (b) review of preprinted physician orders for insomnia and agitation, and (c) routine screening for delirium. We investigated the early outcomes and effects of the Delirium Team Approach program on postoperative delirium.

RESULTS

The incidence of postoperative delirium significantly decreased from 53.3% to 37.0% after implementation of the Delirium Team Approach program (P = .008). Although no intergroup differences were observed in the rates of stroke and reexploration for bleeding, the length of intensive care unit stay and the overall length of postoperative hospital stay were shorter in the postintervention group. Hospital costs, excluding surgery, and the cost during intensive care unit stay were lower in the postintervention group. Multivariable analysis showed that the Delirium Team Approach program was associated with a reduction in postoperative delirium (odds ratio, 0.38; 95% confidence interval, 0.21-0.67; P = .001). Other predictors of delirium included age, dementia, chronic kidney disease, and intubation time. After risk adjustment using propensity score matching, the rate of postoperative delirium was lower in the postintervention group.

CONCLUSIONS

Implementation of the Delirium Team Approach program was associated with a lower incidence of postoperative delirium in patients who underwent cardiovascular surgery.

Risk factors of postoperative delirium after cardiac surgery: a meta-analysis

Background

Postoperative delirium is a frequent event after cardiac surgery. This meta-analysis aimed to identify relevant risk factors.

Method

In this meta-analysis, all original researches regarding patients undergoing mixed types of cardiac surgery (excluding transcatheter procedures) and postoperative delirium were evaluated for inclusion. On July 28th 2020, we searched PubMed, Embase, Web of Science and Scopus. Data about name of first author, year of publication, inclusion and exclusion criteria, research design, setting, method of delirium assessment, incidence of delirium, odds ratio (OR) and corresponding 95% confidence interval (CI) of risk factors, and other information relevant was collected. OR and 95% CI were used as metrics for summarized results. Random effects model was applied.

Results

Fourteen reports were included with a total sample size of 13,286. The incidence of delirium ranged from 4.1 to 54.9%. Eight risk factors were identified including aging, diabetes, preoperative depression, mild cognitive impairment, carotid artery stenosis, NYHA functional class III or IV, time of mechanical ventilation and length of intensive care unit stay.

Conclusion

In this study several risk factors associated with postoperative delirium after cardiac surgery were identified. Utilizing the information may allow us to identifying patients at high risk of developing postoperative delirium prior to delirium onset.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01496-w.

Preoperative Acute Pain Is Associated with Postoperative Delirium

Background

Studies have provided some evidence that pain is a risk factor for postoperative delirium (POD). Therefore, we investigated the relationship between preoperative pain and POD after noncardiac surgery.

Methods

POD was assessed with the Montreal Cognitive Assessment, and preoperative cognition was assessed with the Mini-Mental State Examination. Plasma C-reactive protein (CRP) was detected by enzyme-linked immunosorbent assay before surgery. Preoperative pain was classified by its duration before surgery as chronic pain (lasting more than 1 month), acute pain (lasting less than 1 month), or no pain (no obvious pain). Multiple linear regression was used to adjust for confounding.

Results

From October 15, 2018, through August 12, 2019, a total of 67 patients were randomized; 7 were excluded because they were discharged before the seventh postoperative day. The prevalence of POD was significantly higher in the acute pain group (13 of 20; 65%) than in the chronic pain group (5 of 20; 25%) or the no pain group (6 of 20; 30%) (P = 0.019), indicating that delirium is associated with preoperative acute pain. The plasma level of preoperative CRP was also higher in the acute pain group than in the other two groups (mean [interquartile range]: 10.7 [3.3, 29.3] vs 1 [0.5, 3.8]mg/l; P &lt; 0.001), suggesting that elevated preoperative plasma levels of CRP were associated with delirium.

Conclusions

Preoperative acute pain was associated with POD, and increased plasma levels of CRP provide a marker. In addition, we found that illiteracy and advanced age were risk factors for POD.

Reducing Opioid Use in Patients Undergoing Cardiac Surgery - Preoperative, Intraoperative, and Critical Care Strategies

Patients undergoing cardiothoracic surgery are exposed to opioids in the operating room and intensive care unit and after hospital discharge. Opportunities exist to reduce perioperative opioid use at all stages of care and include alternative oral and intravenous medications, novel intraoperative regional anesthetic techniques, and postoperative opioid-sparing sedative and analgesic strategies. In this review, currently used and investigational strategies to reduce the opioid burden for cardiothoracic surgical patients are explored.

Mannitol Is Associated with Less Postoperative Delirium after Aortic Valve Surgery in Patients Treated with Bretschneider Cardioplegia

Background  Heart surgery with extracorporeal circulation (ECC) often leads to postoperative delirium (POD). This is associated with increased morbidity resulting in longer hospital stay and associated costs. The purpose of our study was to analyze the effect of intraoperative mannitol application on POD in patients undergoing elective aortic valve replacement (AVR).

Materials and Method s In our retrospective single-center study, 259 patients underwent elective AVR, using Bretschneider cardioplegic solution for cardiac arrest, between 2014 and 2017. Patients were divided in mannitol ( n  = 188) and nonmannitol ( n  = 71) groups. POD was assessed using the confusion assessment method for the intensive care unit (ICU). Statistical significance was assumed at p  < 0.05.

Results  Baseline patient characteristics did not differ between the groups. Incidence of POD was significantly higher in the nonmannitol group (33.8 vs. 13.8%; p  = 0.001). These patients required longer ventilation time (24.1 vs. 17.1 hours; p  = 0.021), higher reintubation rate (11.3 vs. 2.7%; p  = 0.009), ICU readmission (12.7 vs. 4.8%; p  = 0.026), prolonged ICU (112 vs. 70 hours; p  = 0.040), and hospital stay (17.8 vs. 12.6 days; p  < 0.001), leading to higher expenses (19,349 € vs. 16,606 €, p  < 0.001). A 30-day mortality was not affected, but nonmannitol group showed higher Simplified Acute Physiology Score II score (32.2 vs. 28.7; p  < 0.001). Mannitol substitution was independently associated with lower incidence of POD (odds ratio: 0.40; 95% confidence interval: 0.18–0.89; p  = 0.02).

Conclusion  Treatment with mannitol during ECC was associated with decreased incidence of POD. This was accompanied by shorter ventilation time, ICU and hospital stay, and lower treatment expenses.

Noteworthy Literature in Cardiac Anesthesia for 2019

This article represents a selective review of literature published in 2019. Initial results from PubMed searching for a combination of terms, including cardiac anesthesiology and anesthesiology outcomes, yielded more than 1400 publications. From there, we manually screened the results and identified 5 major themes for the year of 2019, including transcatheter techniques, delirium and anesthesiology, coagulation management following cardiopulmonary bypass, perfusion management with del Nido cardioplegia, and applied clinical research. The following research accomplishments have expanded what is possible and set ambitious goals for the future.

A systematic review of the overlap of fluid biomarkers in delirium and advanced cancer-related syndromes

BACKGROUND

Delirium is a serious and distressing neurocognitive disorder of physiological aetiology that is common in advanced cancer. Understanding of delirium pathophysiology is largely hypothetical, with some evidence for involvement of inflammatory systems, neurotransmitter alterations and glucose metabolism. To date, there has been limited empirical consideration of the distinction between delirium pathophysiology and that of the underlying disease, for example, cancer where these mechanisms are also common in advanced cancer syndromes such as pain and fatigue. This systematic review explores biomarker overlap in delirium, specific advanced cancer-related syndromes and prediction of cancer prognosis.

METHODS

A systematic review (PROSPERO CRD42017068662) was conducted, using MEDLINE, PubMed, Embase, CINAHL, CENTRAL and Web of Science, to identify body fluid biomarkers in delirium, cancer prognosis and advanced cancer-related syndromes of interest. Studies were excluded if they reported delirium tremens only; did not measure delirium using a validated tool; the sample had less than 75% of participants with advanced cancer; measured tissue, genetic or animal biomarkers, or were conducted post-mortem. Articles were screened for inclusion independently by two authors, and data extraction and an in-depth quality assessment conducted by one author, and checked by two others.

RESULTS

The 151 included studies were conducted in diverse settings in 32 countries between 1985 and 2017, involving 28130 participants with a mean age of 69.3 years. Seventy-one studies investigated delirium biomarkers, and 80 studies investigated biomarkers of an advanced cancer-related syndrome or cancer prognosis. Overall, 41 biomarkers were studied in relation to both delirium and either an advanced cancer-related syndrome or prognosis; and of these, 24 biomarkers were positively associated with either delirium or advanced cancer syndromes/prognosis in at least one study. The quality assessment showed large inconsistency in reporting.

CONCLUSION

There is considerable overlap in the biomarkers in delirium and advanced cancer-related syndromes. Improving the design of delirium biomarker studies and considering appropriate comparator/controls will help to better understanding the discrete pathophysiology of delirium in the context of co-existing illness.

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.

The Impact of Acute Kidney Injury in the Perioperative Period on the Incidence of Postoperative Delirium in Patients Undergoing Coronary Artery Bypass Grafting-Observational Cohort Study

Recent data indicate that acute kidney damage leads to inflammation in the brain and other distant organs. The purpose of this study was to investigate the effect of acute kidney injury (AKI) according to the Kidney Disease Improving Global Outcome (KDIGO) criteria on the occurrence of postoperative delirium in patients undergoing coronary artery bypass grafting (CABG). We performed a retrospective cohort analysis that included all consecutive patients undergoing elective CABG. The CAM-ICU (Confusion Assessment Method for Intensive Care Unit) was used for delirium assessment. Patients were divided into four groups, depending on the occurrence of AKI in the perioperative period according to KDIGO criteria. Overall, 902 patients were included in the final analysis, the mean age was 65.95 ± 8.01 years, and 76.83% were males (693/957). The majority of patients presented with normal kidney function-baseline creatinine level of 0.91 ± 0.21 (mg/dL). The incidence of AKI in the perioperative setting was 22.17% (200/902). Postoperative delirium was diagnosed in 115/902 patients (12.75%). Compared with no AKI, the odds of developing POD were increased for KDIGO stage 1 (OR 2.401 (95% confidence interval 1.484–3.884), p < 0.001); KDIGO stage 2 (OR 3.387 (95% confidence interval 1.459–7.866), p = 0.005); and highest for KDIGO stage 3 (OR equal to 9.729 (95% confidence interval 2.675–35.382), p = 0.001). Acute kidney injury, based on AKI staging, should be regarded as an independent risk factor for postoperative delirium after cardiac surgery.

The effects of multimedia education on postoperative delirium in patients undergoing coronary artery bypass graft: A randomized clinical trial

BACKGROUND

Patients undergoing cardiac surgeries are at high risk of developing delirium.

AIMS AND OBJECTIVES

The present study aimed to determine the effects of multimedia education on postoperative delirium in patients undergoing a coronary artery bypass graft.

DESIGN

This study was a randomized clinical trial.

METHODS

In this study, 110 patients undergoing a coronary artery bypass graft were assigned to two groups, control and intervention. Patients in the intervention group received multimedia education, and those in the control group received routine training. The inclusion criteria were experiencing the coronary artery bypass graft for the first time and non-development of post-operative cardiogenic shock or myocardial rupture. After measuring the level of consciousness, patients were examined in terms of delirium using the confusion assessment method for the ICU scale twice a day from admission to discharge from the ICU. The data were statistically analysed using χ² test and Fisher's exact test.

RESULTS

Patients of both groups were matched in terms of demographics. The highest incidence of delirium was observed on the first day after surgery in the intervention group (14.5%) and in the morning of the second day after surgery (29.1%) in the control group. Moreover, there was a significant difference between the two groups in the incidence of delirium in the morning of the second, third, and fourth days after surgery as it was higher in the control group over these days.

CONCLUSION

Considering the lower incidence of post-operative delirium in patients who experienced multimedia education rather than control group, the use of this non-pharmaceutical method is recommended to prevent delirium in such patients.

RELEVANCE TO CLINICAL PRACTICE

Delirium is also an acute organic brain syndrome that often leads to complicated conditions after cardiac surgeries. Fortunately, delirium is a preventable issue. The implementation of multimedia education as a non-pharmacological approach had positive effects on patients' delirium.

Effects of dexamethasone on post-operative cognitive dysfunction and delirium in adults following general anaesthesia: a meta-analysis of randomised controlled trials

Background

Several studies have investigated the effects of dexamethasone on post-operative cognitive dysfunction (POCD) or post-operative delirium (POD); however, their conclusions have been inconsistent. Thus, we conducted a meta-analysis to determine the effects of dexamethasone on POCD and POD in adults following general anaesthesia.

Methods

The Cochrane Central Register of Controlled Trials (2018, Issue 11 of 12) in the Cochrane Library (searched 17 November 2018), MEDLINE OvidSP (1946 to 16 November 2018) and Embase OvidSP (1974 to 16 November 2018) were searched for randomised controlled trials that evaluated the incidence of POCD and POD following dexamethasone administration in adults (age ≥ 18 years) under general anaesthesia. We used the Grading of Recommendations, Assessment, Development and Evaluations framework to assess the quality of the evidence.

Results

Five studies were included (three studies with 855 participants in the dexamethasone group and 538 participants in the placebo group for the incidence of POCD, and two studies with 410 participants in the dexamethasone group and 420 participants in the placebo group for the incidence of POD). There was no significant difference between the dexamethasone group and the placebo group in terms of the incidence of POCD 30 days after surgery (RR [relative risk] 1.00; 95% CI [confidence interval: 0.51, 1.96], P = 1.00, I² = 77%) or the incidence of POD (RR 0.96; 95% CI [0.68, 1.35], P = 0.80, I² = 0%). However, both analyses had some limitations because of limited evidence and clinical heterogeneity, and we considered the quality of the evidence for the post-operative incidence of POCD and POD to be very low.

Conclusions

This meta-analysis revealed that prophylactic dexamethasone did not reduce the incidence of POCD and POD. Trials of alternative preventive strategies for POCD and POD, as well as a better understanding of the pathophysiology of those complex syndromes, are still needed to make progress in this field.

Trial registrationr

This study is registered with PROSPERO, 23 October 2018, number CRD42018114552. Available from https://www.crd.york.ac.uk/PROSPERO/#recordDetails.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0783-x) contains supplementary material, which is available to authorized users.

Association of earlier extubation and postoperative delirium after coronary artery bypass grafting

OBJECTIVES

Earlier extubation after cardiac surgery is reported to have benefits on length of stay and complication rates, but the influence on postoperative delirium remains unclear. We sought to determine the effect of earlier extubation on delirium after coronary artery bypass grafting.

METHODS

A single-center retrospective review of consecutive isolated coronary artery bypass grafting patients from January 1, 2010, to December 31, 2015, was conducted. Baseline demographic characteristics, preoperative comorbidities, intraoperative data, and postoperative data were collected. A multivariable logistic regression was performed with analysis limited to extubation within the first 24 hours postoperatively.

RESULTS

We identified 2561 eligible patients. Delirium occurred in 13.9% (n = 357). Duration of postoperative mechanical ventilation was associated with higher delirium rates following adjustment, particularly after 12 to 24 hours (hourly odds ratio, 1.12; 95% confidence interval, 1.05-1.19; P < .001). No association was observed during the time period from 0 to 12 hours (hourly odds ratio, 1.02; 95% confidence interval, 0.99-1.06; P = .218). Major adverse events were associated with duration of ventilation after 0 to 12 hours (hourly odds ratio, 1.08; 95% confidence interval, 1.03-1.14; P < .002) but not after 12 to 24 hours (hourly odds ratio, 1.04; 95% CI, 0.96-1.14; P = .316). The overall rate of reintubation was 2.9% (n = 73).

CONCLUSIONS

Our findings suggest that delirium rates increase with lengthier postoperative ventilation times. This study provides the basis for consideration of the appropriate selection of earlier extubation to minimize delirium in patients undergoing cardiac surgery.

Delirium following total joint replacement surgery

Postoperative delirium (POD) is a common complication associated with increased resource utilization, morbidity and mortality. Our institution screens all postsurgical patients for postoperative delirium. The study aim was to perform an automated interrogation of the electronic health records to estimate the incidence of and identify associated risk factors for POD following total joint arthroplasty (TJA). Adult patients who underwent TJA with a multimodal analgesia protocol, including peripheral nerve blockade, from 2008 through 2012, underwent automated chart review. POD was identified by routine nursing assessment and administrative billing codes. Of 11,970 patients, 181 (1.5%) were identified to have POD. Older age (odds ratio, 95% CI 2.20, 1.80-2.71 per decade, p < 0.001), dementia (7.44, 3.54-14.60, p < 0.001), diabetes mellitus (1.70, 1.1.5-2.47, p = 0.009), renal disease (1.68, 1.03-2.65, p = 0.039), blood transfusions (2.04, 1.14-3.52, p = 0.017), and sedation during anesthesia recovery (1.76, 1.23-2.51, p = 0.002) were associated with POD. Anesthetic management was not associated with POD risk. Patients who developed POD required greater healthcare resources. Dementia is strongly associated with POD. The association between POD and transfusions may reflect higher acuity patients or detrimental effect of blood. Postoperative sedation should be recognized as a warning sign of increased risk.

Diabetes and elevated preoperative HbA1c level as risk factors for postoperative delirium after cardiac surgery: an observational cohort study

INTRODUCTION

Postoperative delirium (POD) is a common complication of cardiac surgery associated with increased mortality, morbidity, and long-term cognitive dysfunction. Diabetic patients, especially those with poor diabetes control and long-standing hyperglycemia, may be at risk of developing delirium. The aim of this study was to analyze whether the occurrence of POD in cardiac surgery is associated with diabetes or elevated preoperative glycated hemoglobin (HbA1c) level.

MATERIALS AND METHODS

We performed a cohort analysis of prospectively collected data from a register of cardiac surgery department of a university hospital. Delirium assessment was performed twice a day during the first 5 days after the operation based on Diagnostic Statistical Manual of Mental Disorders, fifth edition criteria.

RESULTS

We analyzed a cohort of 3,178 consecutive patients, out of which 1,010 (31.8%) were diabetic and 502 (15.8%) were diagnosed with POD. Patients with delirium were more often diabetic (42.03% vs 29.86%, P<0.001) and on oral diabetic medications (34.66% vs 24.07%, P<0.001), no difference was found in patients with insulin treatment. Preoperative HbA1c was elevated above normal (≥6%) in more delirious than nondelirious patients (44.54% vs 33.04%, P<0.001), but significance was reached only in nondiabetic patients (20.44% vs 14.86%, P=0.018). In univariate analysis, the diagnosis of diabetes was associated with an increased risk of developing POD (OR: 1.703, 95% CI: 1.401-2.071, P<0.001), but only for patients on oral diabetic medications (OR: 1.617, 95% CI: 1.319-1.983, P<0.001) and an association was noted between HbA1c and POD (OR: 1.269, 95% CI: 1.161-1.387, P<0.001). Multivariate analysis controlled for diabetes showed that POD was associated with age, heart failure, preoperative creatinine, extracardiac arteriopathy, and preoperative HbA1c level.

CONCLUSION

More diabetic patients develop POD after cardiac surgery than nondiabetic patients. Elevated preoperative HbA1c level is a risk factor for postcardiac surgery delirium regardless of the diagnosis of diabetes.

Mycobacterium vaccae immunization protects aged rats from surgery-elicited neuroinflammation and cognitive dysfunction

Aging is a major risk factor for developing postoperative cognitive dysfunction. Neuroinflammatory processes, which can play a causal role in the etiology of postoperative cognitive dysfunction, are potentiated or primed as a function of aging. Here we explored whether exposure to a microorganism with immunoregulatory and anti-inflammatory properties, Mycobacterium vaccae NCTC 11659 (M. vaccae), could ameliorate age-associated neuroinflammatory priming. Aged (24 months) and adult (3 months) male F344XBN rats were immunized with heat-killed M. vaccae (3 injections, once per week) before undergoing a laparotomy or anesthesia control procedure. Aged, but not young rats, showed postoperative learning/memory deficits in a fear-conditioning paradigm. Importantly, M. vaccae immunization protected aged rats from these surgery-induced cognitive impairments. M. vaccae immunization also shifted the aged proinflammatory hippocampal microenvironment toward an anti-inflammatory phenotype. Furthermore, M. vaccae immunization reduced age-related hyperinflammatory responses in isolated hippocampal microglia. Overall, our novel data suggest that M. vaccae can induce an anti-inflammatory milieu in the aged brain and thus mitigate the neuroinflammatory and cognitive impairments induced by surgery.

Neurocognitive Function after Cardiac Surgery: From Phenotypes to Mechanisms

For half a century, it has been known that some patients experience neurocognitive dysfunction after cardiac surgery; however, defining its incidence, course, and causes remains challenging and controversial. Various terms have been used to describe neurocognitive dysfunction at different times after cardiac surgery, ranging from "postoperative delirium" to "postoperative cognitive dysfunction or decline." Delirium is a clinical diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Postoperative cognitive dysfunction is not included in the DSM-5 and has been heterogeneously defined, though a recent international nomenclature effort has proposed standardized definitions for it. Here, the authors discuss pathophysiologic mechanisms that may underlie these complications, review the literature on methods to prevent them, and discuss novel approaches to understand their etiology that may lead to novel treatment strategies. Future studies should measure both delirium and postoperative cognitive dysfunction to help clarify the relationship between these important postoperative complications.

Stress and aging act through common mechanisms to elicit neuroinflammatory priming

Over the course of an animal's lifespan, there is a protracted breakdown in basic homeostatic functions. Stressors (both psychological and physiological) can accelerate this process and compromise multiple homeostatic mechanisms. For example, both stress and aging can modulate neuroinflammatory function and cause a primed phenotype resulting in a heightened neuroinflammatory profile upon immune activation. Microglia, the brain's resident myeloid cell, produce "silent" immune machinery in response to stress and aging that does not cause immediate immune activation; rather, these changes prime the cell for a subsequent immune insult. Primed microglia exhibit a hyperinflammatory response upon immune activation that can exacerbate pathology. In this review, we will explore parallels between stress- and aging-induced neuroinflammatory priming. First, we will provide a background on the basic principles of neuroimmunology. Next, we will discuss evidence that neuroinflammatory responses become primed in the context of both stress and aging. We will also describe cell-specific contributions to neuroinflammatory priming with a focus on microglia. Finally, common mechanisms underlying priming in the context of stress and aging will be discussed: these mechanisms include glucocorticoid signaling; accumulation of danger signals; dis-inhibition of microglia; and breakdown of circadian rhythms. Overall, there are multifarious parallels between stress- and aging-elicited neuroinflammatory priming, suggesting that stress may promote a form of premature aging. Further unravelling mechanisms underlying priming could lead to improved treatments for buffering against stress- and aging-elicited behavioral pathologies.

Early delirium after cardiac surgery: an analysis of incidence and risk factors in elderly (≥65 years) and very elderly (≥80 years) patients

Introduction

Postoperative delirium is a common complication of cardiac surgery associated with increased mortality, morbidity, and long-term cognitive dysfunction. The aim of this study was to identify incidence and risk factors of delirium in elderly (≥65 years) and very elderly (≥80 years) patients undergoing major cardiac surgery.

Materials and methods

We performed a retrospective cohort analysis of prospectively collected data from a register of the cardiac surgery department of a tertiary referral university hospital between 2014 and 2016. Analysis was performed in two groups, ≥65 years and ≥80 years.

Results

We analyzed 1,797 patients ≥65 years, including 230 (7.24%) patients ≥80 years. Delirium was diagnosed in 21.4% (384/1,797) of patients above 65 years, and in 33.5% (77/230) of octogenarians. Early mortality did not differ between patients with and without delirium. Intensive care unit (ICU) stay (p<0.001), hospital stay (p<0.001), and intubation time (p=0.002) were significantly longer in patients undergoing cardiac surgery ≥65 years with delirium. According to multivariable analysis, <65 years, age (odds ratio [OR] 1.036, p=0.002), low ejection fraction (OR 1.634, p=0.035), diabetes (1.346, p=0.019), and extracardiac arteriopathy (OR 1.564, p=0.007) were found to be independent predictors of post-cardiac surgery delirium. Postoperative risk factors for developing delirium ≥65 years were atrial fibrillation (1.563, p=0.001), postoperative pneumonia (OR 1.896, p=0.022), elevated postoperative creatinine (OR 1.384, p=0.004), and prolonged hospitalization (OR 1.019, p=0.009).

Conclusion

Patients above 65 years of age with postoperative delirium have poorer outcome and are more likely to have prolonged hospitalization and ICU stay, and longer intubation times, but 30-day mortality is not increased. In our study, eight independent risk factors for development of post-cardiac surgery delirium were age, low ejection fraction, diabetes, extracardiac arteriopathy, postoperative atrial fibrillation, pneumonia, elevated creatinine, and prolonged hospitalization time.

Nonpharmacologic and Medication Minimization Strategies for the Prevention and Treatment of ICU Delirium: A Narrative Review

Delirium is a multifactorial entity, and its understanding continues to evolve. Delirium has been associated with increased morbidity, mortality, length of stay, and cost for hospitalized patients, especially for patients in the intensive care unit (ICU). Recent literature on delirium focuses on specific pharmacologic risk factors and pharmacologic interventions to minimize course and severity of delirium. While medication management clearly plays a role in delirium management, there are a variety of nonpharmacologic interventions, pharmacologic minimization strategies, and protocols that have been recently described. A PubMed search was performed to review the evidence for nonpharmacologic management, pharmacologic minimization strategies, and prevention of delirium for patients in the ICU. Recent approaches were condensed into 10 actionable steps to manage delirium and minimize medications for ICU patients and are presented in this review.

Influence of physical restraint on delirium of adult patients in ICU: A nested case-control study

AIMS AND OBJECTIVES

To investigate the impact of physical restraint on delirium of adult patients in intensive care unit.

BACKGROUND

Delirium is a common clinical syndrome in intensive care unit, correlated with various adverse clinical outcomes. Physical restraint is a precipitating factor for delirium; however, the effect of physical restraint on delirium, such as duration, number and appliance is still unclear.

DESIGN

A nested case-control study.

METHODS

A cohort of 593 intensive care unit patients were observed for 12 months, and 447 of them who received physical restraint were included for analysis. Delirium was assessed using the Confusion Assessment Method for the intensive care unit. During hospitalisation in intensive care unit, newly-onset delirium patients (the delirium group), and nondelirium patients of similar age, same gender, and conditions of mechanical ventilation and sedative drug usage (the nondelirium group) were included as the matching criteria. Patient data were acquired by reviewing medical and nursing electronic records.

RESULTS

Among the 447 patients that had been physically restrained, 178 (39.8%) developed delirium. Delirium risk in patients with restraint ≥6 days was 26.30 times higher than in those <6 days. Patients who had two and three times of restraint had a 2.38-fold and 3.62-fold higher risk of delirium than those with one time of restraint. However, the appliance, site, time to apply and remove restraint had no effect on the incidence of delirium.

CONCLUSIONS

The incidence of delirium is high when patients use physical restraint. Duration and number of restraint are positively related to delirium. Restrictions on the use of restraint in intensive care unit are required to reduce the occurrence of delirium.

RELEVANCE TO CLINICAL PRACTICE

To reduce delirium risk of patients in intensive care unit, nurses need to assess the risk of physical restraint and consider alternative measures, thereby to achieve the minimisation of the use of restraint.

Inflammatory markers in postoperative delirium (POD) and cognitive dysfunction (POCD): A meta-analysis of observational studies

Background

The aim of this study was to summarize and discuss the similarities and differences in inflammatory biomarkers in postoperative delirium (POD) and cognitive dysfunction (POCD).

Methods

A systematic retrieval of literature up to June 2017 in PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, and the Wanfang database was conducted. Extracted data were analyzed with STATA (version 14). The standardized mean difference (SMD) and the 95% confidence interval (95% CI) of each indicator were calculated using a random effect model. We also performed tests of heterogeneity, sensitivity analysis, assessments of bias, and meta-regression in this meta-analysis.

Results

A total of 54 observational studies were included. By meta-analysis we found significantly increased C-reactive protein (CRP) (9 studies, SMD 0.883, 95% CI 0.130 to 1.637, P = 0.022 in POD; 10 studies, SMD -0.133, 95% CI -0.512 to 0.246, P = 0.429 in POCD) and interleukin (IL)-6 (7 studies, SMD 0.386, 95% CI 0.054 to 0.717, P = 0.022 in POD; 16 studies, SMD 0.089, 95% CI -0.133 to 0.311, P = 0.433 in POCD) concentrations in both POD and POCD patients. We also found that the SMDs of CRP and IL-6 from POCD patients were positively correlated with surgery type in the meta-regression (CRP: Coefficient = 1.555365, P = 0.001, 10 studies; IL-6: Coefficient = -0.6455521, P = 0.086, 16 studies).

Conclusion

Available evidence from medium-to-high quality observational studies suggests that POD and POCD are indeed correlated with the concentration of peripheral and cerebrospinal fluid (CSF) inflammatory markers. Some of these markers, such as CRP and IL-6, play roles in both POD and POCD, while others are specific to either one of them.

Preoperative medication use and postoperative delirium: a systematic review

BACKGROUND

Medications are frequently reported as both predisposing factors and inducers of delirium. This review evaluated the available evidence and determined the magnitude of risk of postoperative delirium associated with preoperative medication use.

METHODS

A systematic search in Medline and EMBASE was conducted using MeSH terms and keywords for postoperative delirium and medication. Studies which included patients 18 years and older who underwent major surgery were included. The methodological quality of included studies was assessed independently by two authors using the Newcastle-Ottawa quality assessment scale for cohort studies.

RESULTS

Twenty-nine studies; 25 prospective cohort, three retrospective cohort and one post hoc analysis of RCT data were included. Only four specifically aimed to assess medicines as an independent predictor of delirium, all other studies included medicines among a number of potential predictors of delirium. Of the studies specifically testing the association with a medication class, preoperative use of beta-blockers (OR = 2.06[1.18-3.60]) in vascular surgery and benzodiazepines RR 2.10 (1.23-3.59) prior to orthopedic surgery were significant. However, evidence is from single studies only. Where medicines were included as one possible factor among many, hypnotics had a similar risk estimate to the benzodiazepine study, with one significant and one non-significant result. Nifedipine use prior to cardiac surgery was found to be significantly associated with delirium. The non-specific grouping of psychoactive medication use preoperatively was generally higher with an associated two-to-seven-fold higher risk of postoperative delirium, while only two studies included narcotics without other agents, with one significant and one non-significant result.

CONCLUSIONS

There was a limited number of high quality studies in the literature quantifying the direct association between preoperative medication use and postsurgical delirium. More studies are required to evaluate the association of specific preoperative medications on the risk of postoperative delirium so that comprehensive guidelines for medicine use prior to surgery can be developed to aid delirium prevention.

TRIAL REGISTRATION

This systematic review has been registered on PROSPERO International prospective register of systematic reviews (Registration number: CRD42016051245 ).

The Comparative Risk of Delirium with Different Opioids: A Systematic Review

Objective

There is substantial evidence that the use of opioids increases the risk of adverse outcomes such as delirium, but whether this risk differs between the various opioids remains controversial. In this systematic review, we evaluate and discuss possible differences in the risk of delirium from the use of various types of opioids in older patients.

Methods

We performed a search in MEDLINE by combining search terms on delirium and opioids. A specific search filter for use in geriatric medicine was used. Quality was scored according to the quality assessment for cohort studies of the Dutch Cochrane Institute.

Results

Six studies were included, all performed in surgical departments and all observational. No study was rated high quality, one was rated moderate quality, and five were rated low quality. Information about dose, route, and timing of administration of the opioid was frequently missing. Pain and other important risk factors of delirium were often not taken into account. Use of tramadol or meperidine was associated with an increased risk of delirium, whereas the use of morphine, fentanyl, oxycodone, and codeine were not, when compared with no opioid. Meperidine was also associated with an increased risk of delirium compared with other opioids, whereas tramadol was not. The risk of delirium appeared to be lower with hydromorphone or fentanyl, compared with other opioids. Numbers used for comparisons were small.

Conclusion

Some data suggest that meperidine may lead to a higher perioperative risk for delirium; however, high-quality studies that compare different opioids are lacking. Further comparative research is needed.

Electronic supplementary material

The online version of this article (doi:10.1007/s40266-017-0455-9) contains supplementary material, which is available to authorized users.

Pathophysiological and behavioral effects of systemic inflammation in aged and diseased rodents with relevance to delirium: A systematic review

Delirium is a frequent outcome for aged and demented patients that suffer a systemic inflammatory insult. Animal models that reconstruct these etiological processes have potential to provide a better understanding of the pathophysiology of delirium. Therefore, we systematically reviewed animal studies in which systemic inflammation was superimposed on aged or diseased animal models. In total, 77 studies were identified. Aged animals were challenged with a bacterial endotoxin in 29 studies, 25 studies superimposed surgery on aged animals, and in 6 studies a bacterial infection, Escherichia coli (E. coli), was used. Diseased animals were challenged with a bacterial endotoxin in 15 studies, two studies examined effects of the cytokine IL-1β, and one study used polyinosinic:polycytidilic acid (poly I:C). This systematic review analyzed the impact of systemic inflammation on the production of inflammatory and neurotoxic mediators in peripheral blood, cerebrospinal fluid (CSF), and on the central nervous system (CNS). Moreover, concomitant behavioral and cognitive symptoms were also evaluated. Finally, outcomes of behavioral and cognitive tests from animal studies were compared to features and symptoms present in delirious patients.

Delirium in Children After Cardiac Bypass Surgery

OBJECTIVES

To describe the incidence of delirium in pediatric patients after cardiac bypass surgery and explore associated risk factors and effect of delirium on in-hospital outcomes.

DESIGN

Prospective observational single-center study.

SETTING

Fourteen-bed pediatric cardiothoracic ICU.

PATIENTS

One hundred ninety-four consecutive admissions following cardiac bypass surgery, 1 day to 21 years old.

INTERVENTIONS

Subjects were screened for delirium daily using the Cornell Assessment of Pediatric Delirium.

MEASUREMENTS AND MAIN RESULTS

Incidence of delirium in this sample was 49%. Delirium most often lasted 1-2 days and developed within the first 1-3 days after surgery. Age less than 2 years, developmental delay, higher Risk Adjustment for Congenital Heart Surgery 1 score, cyanotic disease, and albumin less than three were all independently associated with development of delirium in a multivariable model (all p < 0.03). Delirium was an independent predictor of prolonged ICU length of stay, with patients who were ever delirious having a 60% increase in ICU days compared with patients who were never delirious (p < 0.01).

CONCLUSIONS

In our institution, delirium is a frequent problem in children after cardiac bypass surgery, with identifiable risk factors. Our study suggests that cardiac bypass surgery significantly increases children's susceptibility to delirium. This highlights the need for heightened, targeted delirium screening in all pediatric cardiothoracic ICUs to potentially improve outcomes in this vulnerable patient population.

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.

Dexmedetomidine for prevention of delirium in elderly patients after non-cardiac surgery: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Delirium is a postoperative complication that occurs frequently in patients older than 65 years, and presages adverse outcomes. We investigated whether prophylactic low-dose dexmedetomidine, a highly selective α₂ adrenoceptor agonist, could safely decrease the incidence of delirium in elderly patients after non-cardiac surgery.

METHODS

We did this randomised, double-blind, placebo-controlled trial in two tertiary-care hospitals in Beijing, China. We enrolled patients aged 65 years or older, who were admitted to intensive care units after non-cardiac surgery, with informed consent. We used a computer-generated randomisation sequence (in a 1:1 ratio) to randomly assign patients to receive either intravenous dexmedetomidine (0·1 μg/kg per h, from intensive care unit admission on the day of surgery until 0800 h on postoperative day 1), or placebo (intravenous normal saline). Participants, care providers, and investigators were all masked to group assignment. The primary endpoint was the incidence of delirium, assessed twice daily with the Confusion Assessment Method for intensive care units during the first 7 postoperative days. Analyses were done by intention-to-treat and safety populations. This study is registered with Chinese Clinical Trial Registry, www.chictr.org.cn, number ChiCTR-TRC-10000802.

FINDINGS

Between Aug 17, 2011, and Nov 20, 2013, of 2016 patients assessed, 700 were randomly assigned to receive either placebo (n=350) or dexmedetomidine (n=350). The incidence of postoperative delirium was significantly lower in the dexmedetomidine group (32 [9%] of 350 patients) than in the placebo group (79 [23%] of 350 patients; odds ratio [OR] 0·35, 95% CI 0·22-0·54; p<0·0001). Regarding safety, the incidence of hypertension was higher with placebo (62 [18%] of 350 patients) than with dexmedetomidine (34 [10%] of 350 patients; 0·50, 0·32-0·78; p=0·002). Tachycardia was also higher in patients given placebo (48 [14%] of 350 patients) than in patients given dexmedetomidine (23 [7%] of 350 patients; 0·44, 0·26-0·75; p=0·002). Occurrence of hypotension and bradycardia did not differ between groups.

INTERPRETATION

For patients aged over 65 years who are admitted to the intensive care unit after non-cardiac surgery, prophylactic low-dose dexmedetomidine significantly decreases the occurrence of delirium during the first 7 days after surgery. The therapy is safe.

FUNDING

Braun Anaesthesia Scientific Research Fund and Wu Jieping Medical Foundation, Beijing, China. Study drugs were manufactured and supplied by Jiangsu Hengrui Medicine Co, Ltd, Jiangsu, China.