Independent Predictors of the Duration and Overall Burden of Postoperative Delirium After Cardiac Surgery in Adults: An Observational Cohort Study

Serum Neurofilament Light and Postoperative Delirium in Cardiac Surgery: A Preplanned Secondary Analysis of a Prospective Observational Study

BACKGROUND

Impaired cognition is a major predisposing factor for postoperative delirium, but it is not systematically assessed. Anesthesia and surgery may cause postoperative delirium by affecting brain integrity. Neurofilament light in serum reflects axonal injury. Studies evaluating the perioperative course of neurofilament light in cardiac surgery have shown conflicting results. The authors hypothesized that postoperative serum neurofilament light values would be higher in delirious patients, and that baseline concentrations would be correlated with patients' cognitive status and would identify patients at risk of postoperative delirium.

METHODS

This preplanned secondary analysis included 220 patients undergoing elective cardiac surgery with cardiopulmonary bypass. A preoperative cognitive z score was calculated after a neuropsychological evaluation. Quantification of serum neurofilament light was performed by the Simoa (Quanterix, USA) technique before anesthesia, 2 h after surgery, on postoperative days 1, 2, and 5. Postoperative delirium was assessed using the Confusion Assessment Method for Intensive Care Unit, the Confusion Assessment Method, and a chart review.

RESULTS

A total of 65 of 220 (29.5%) patients developed postoperative delirium. Delirious patients were older (median [25th percentile, 75th percentile], 74 [64, 79] vs. 67 [59, 74] yr; P < 0.001) and had lower cognitive z scores (-0.52 ± 1.14 vs. 0.21 ± 0.84; P < 0.001). Postoperative neurofilament light concentrations increased in all patients up to day 5, but did not predict delirium when preoperative concentrations were considered. Baseline neurofilament light values were significantly higher in patients who experienced delirium. They were influenced by age, cognitive z score, renal function, and history of diabetes mellitus. Baselines values were significantly correlated with cognitive z scores (r, 0.49; P < 0.001) and were independently associated with delirium whenever the patient's cognitive status was not considered (hazard ratio, 3.34 [95% CI, 1.07 to 10.4]).

CONCLUSIONS

Cardiac surgery is associated with axonal injury, because neurofilament light concentrations increased postoperatively in all patients. However, only baseline neurofilament light values predicted postoperative delirium. Baseline concentrations were correlated with poorer cognitive scores, and they independently predicted postoperative delirium whenever patient's cognitive status was undetermined.

EDITOR’S PERSPECTIVE

Former smoking, but not active smoking, is associated with delirium in postoperative ICU patients: a matched case-control study

Objective

To examine the relationship between current and former smoking and the occurrence of delirium in surgical Intensive Care Unit (ICU) patients.

Methods

We conducted a single center, case-control study involving 244 delirious and 251 non-delirious patients that were admitted to our ICU between 2018 and 2022. Using propensity score analysis, we obtained 115 pairs of delirious and non-delirious patients matched for age and Simplified Acute Physiology Score II (SAPS II). Both groups of patients were further stratified into non-smokers, active smokers and former smokers, and logistic regression was performed to further investigate potential confounders.

Results

Our study revealed a significant association between former smoking and the incidence of delirium in ICU patients, both in unmatched (adjusted odds ratio (OR): 1.82, 95% confidence interval (CI): 1.17-2.83) and matched cohorts (OR: 3.0, CI: 1.53-5.89). Active smoking did not demonstrate a significant difference in delirium incidence compared to non-smokers (unmatched OR = 0.98, CI: 0.62-1.53, matched OR = 1.05, CI: 0.55-2.0). Logistic regression analysis of the matched group confirmed former smoking as an independent risk factor for delirium, irrespective of other variables like surgical history (p = 0.010). Notably, also respiratory and vascular surgeries were associated with increased odds of delirium (respiratory: OR: 4.13, CI: 1.73-9.83; vascular: OR: 2.18, CI: 1.03-4.59). Medication analysis showed that while Ketamine and Midazolam usage did not significantly correlate with delirium, Morphine use was linked to a decreased likelihood (OR: 0.27, 95% CI: 0.13-0.55).

Discussion

Nicotine's complex neuropharmacological impact on the brain is still not fully understood, especially its short-term and long-term implications for critically ill patients. Although our retrospective study cannot establish causality, our findings suggest that smoking may induce structural changes in the brain, potentially heightening the risk of postoperative delirium. Intriguingly, this effect seems to be obscured in active smokers, potentially due to the recognized neuroprotective properties of nicotine. Our results motivate future prospective studies, the results of which hold the potential to substantially impact risk assessment procedures for surgeries.

Butyrylcholinesterase activity in patients with postoperative delirium after cardiothoracic surgery or percutaneous valve replacement- an observational interdisciplinary cohort study

BACKGROUND AND OBJECTIVES

Postoperative delirium is a frequent and severe complication after cardiac surgery. Activity of butyrylcholinesterase (BChE) has been discussed controversially regarding a possible role in its development. This study aimed to investigate the relevance of BChE activity as a biomarker for postoperative delirium after cardiac surgery or percutaneous valve replacement.

METHODS

A total of 237 patients who received elective cardiothoracic surgery or percutaneous valve replacement at a tertiary care centre were admitted preoperatively. These patients were tested with the Montreal Cognitive Assessment investigating cognitive deficits, and assessed for postoperative delirium twice daily for three days via the 3D-CAM or the CAM-ICU, depending on their level of consciousness. BChE activity was measured at three defined time points before and after surgery.

RESULTS

Postoperative delirium occurred in 39.7% of patients (n = 94). Univariate analysis showed an association of pre- and postoperative BChE activity with its occurrence (p = 0.037, p = 0.001). There was no association of postoperative delirium and the decline in BChE activity (pre- to postoperative, p = 0.327). Multivariable analysis including either preoperative or postoperative BChE activity as well as age, MoCA, type 2 diabetes mellitus, coronary heart disease, type of surgery and intraoperative administration of red-cell concentrates was performed. Neither preoperative nor postoperative BChE activity was independently associated with the occurrence of postoperative delirium (p = 0.086, p = 0.484). Preoperative BChE activity was lower in older patients (B = -12.38 (95% CI: -21.94 to -2.83), p = 0.011), and in those with a history of stroke (B = -516.173 (95% CI: -893.927 to -138.420), p = 0.008) or alcohol abuse (B = -451.47 (95% CI: -868.38 to -34.55), p = 0.034). Lower postoperative BChE activity was independently associated with longer procedures (B = -461.90 (95% CI: -166.34 to -757.46), p = 0.002), use of cardiopulmonary bypass (B = -262.04 (95% CI: -485.68 to -38.39), p = 0.022), the number of administered red cell-concentrates (B = -40.99 (95% CI: -67.86 to -14.12), p = 0.003) and older age (B = -9.35 (95% CI: -16.04 to -2.66), p = 0.006).

CONCLUSION

BChE activity is not independently associated with the occurrence of postoperative delirium. Preoperative BChE values are related to patients' morbidity and vulnerability, while postoperative activities reflect the severity, length and complications of surgery.

Effect of postoperative delirium after cardiovascular surgery on 5-year mortality

INTRODUCTION

Postoperative delirium is a common complication after cardiovascular surgery. A meta-analysis revealed that postoperative delirium was associated with cognitive decline and dementia, which may affect long-term mortality. However, few studies have reported the association between postoperative delirium after cardiovascular surgery and long-term postoperative mortality. Therefore, we investigated the effect of postoperative delirium on 5-year survival rates of patients who underwent cardiovascular surgery.

METHODS

We retrospectively reviewed the records of patients who underwent cardiovascular surgery with cardiopulmonary bypass from January 2016 to December 2019. Postoperative delirium was defined as an Intensive Care Delirium Screening score ≥ 3, which might include subclinical delirium. Cox proportional hazards modeling was performed to assess the association between postoperative delirium and mortality. Postoperative mortality in patients with and without delirium was assessed using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Postoperative delirium was observed in 562 (31.9%) of 1731 patients. There were more elderly patients, more emergent surgery procedures, longer operative time, and larger transfusion volume in the postoperative delirium group. Cox regression analyses showed that delirium (hazard ratio (HR), 1.501; 95% confidence interval (CI), 1.053-2.140; p = 0.025) and emergent surgery (HR, 3.380; 95% CI, 2.231-5.122; p < 0.001) are significantly associated with 5-year mortality. Among patients who underwent elective surgery, postoperative delirium (HR, 1.987; 95% CI, 1.135-3.481; p = 0.016) is significantly associated with 5-year mortality. Kaplan-Meier survival analysis revealed that patients with postoperative delirium had significantly higher 5-year mortality.

CONCLUSIONS

Patients with postoperative delirium after cardiovascular surgery have significantly higher 5-year mortality.

Intra-operative electroencephalogram frontal alpha-band spectral analysis and postoperative delirium in cardiac surgery: A prospective cohort study

BACKGROUND

Postoperative delirium (POD) remains a frequent complication after cardiac surgery, with pre-operative cognitive status being one of the main predisposing factors. However, performing complete pre-operative neuropsychological testing is challenging. The magnitude of frontal electroencephalographic (EEG) α oscillations during general anaesthesia has been related to pre-operative cognition and could constitute a functional marker for brain vulnerability.

OBJECTIVE

We hypothesised that features of intra-operative α-band activity could predict the occurrence of POD.

DESIGN

Single-centre prospective observational study.

SETTING

University hospital, from 15 May 2019 to 15 December 2021.

PATIENTS

Adult patients undergoing elective cardiac surgery.

MAIN OUTCOME MEASURES

Pre-operative cognitive status was assessed by neuropsychological tests and scored as a global z score. A 5-min EEG recording was obtained 30 min after induction of anaesthesia. Anaesthesia was maintained with sevoflurane. Power and peak frequency in the α-band were extracted from the frequency spectra. POD was assessed using the Confusion Assessment Method for Intensive Care Unit, the Confusion Assessment Method and a chart review.

RESULTS

Sixty-five (29.5%) of 220 patients developed POD. Delirious patients were significantly older with median [IQR] ages of 74 [64 to 79] years vs. 67 [59 to 74] years; P  < 0.001) and had lower pre-operative cognitive z scores (-0.52 ± 1.14 vs. 0.21 ± 0.84; P  < 0.001). Mean α power (-14.03 ± 4.61 dB vs. -11.59 ± 3.37 dB; P  < 0.001) and maximum α power (-11.36 ± 5.28 dB vs. -8.85 ± 3.90 dB; P  < 0.001) were significantly lower in delirious patients. Intra-operative mean α power was significantly associated with the probability of developing POD (adjusted odds ratio, 0.88; 95% confidence interval (CI), 0.81 to 0.96; P  = 0.007), independently of age and only whenever cognitive status was not considered.

CONCLUSION

A lower intra-operative frontal α-band power is associated with a higher incidence of POD after cardiac surgery. Intra-operative measures of α power could constitute a means of identifying patients at risk of this complication.

TRIAL REGISTRATION

NCT03706989.

Diagnosing delirium in perioperative and intensive care medicine

PURPOSE OF REVIEW

This article reviews the current literature on instruments used for screening and diagnosing delirium in perioperative and intensive care medicine. It summarizes recent findings to guide clinicians and researchers in choosing the most appropriate tools.

RECENT FINDINGS

The incidence of delirium in hospitalized patients ranges from 5% to over 50%, depending on the population of patients studied. Failure to diagnose delirium in a timely manner is associated with serious adverse outcomes, including death and institutionalization. Valid assessment tests are needed for delirium detection, as early identification and treatment of delirium may help to prevent complications. Currently, there are more than 30 available instruments, which have been developed to assist with the screening and diagnosis of delirium. However, these tools vary greatly in sensitivity, specificity, and administration time, and their overabundance challenges the selection of specific tool as well as direct comparisons and interpretation of results across studies.

SUMMARY

Overlooking or misdiagnosing delirium may result in poor patient outcomes. Familiarizing healthcare workers with the variety of delirium assessments and selecting the most appropriate tool to their needs is an important step toward improving awareness and recognition of delirium.

Sarcopenia, malnutrition and cognition affect physiotherapy frequency during geriatric rehabilitation: RESORT cohort

BACKGROUND

Physiotherapy (PT) is important to optimize functional recovery in geriatric rehabilitation. The dose of PT received by inpatients during geriatric rehabilitation and the determinants of dose are unknown.

OBJECTIVES

Describe PT dose in terms of total number of sessions, frequency, duration and type of sessions, and inpatient characteristics determining the frequency of PT in geriatric rehabilitation.

METHODS

The observational, longitudinal REStORing health of acutely unwell adulTs (RESORT) cohort consists of geriatric inpatients undergoing rehabilitation including PT (Melbourne, Australia). Ordinal regression was used to assess the determinants of PT frequency (total number of sessions divided by length of stay in weeks). Malnutrition, frailty and sarcopenia were diagnosed according to the Global Leadership Initiative on Malnutrition criteria, Clinical Frailty Scale and revised definition of the European Working Group on Sarcopenia in Older People respectively.

RESULTS

Of the 1890 participants, 1799, median (quartile 1; quartile 3) age 83.4 (77.6; 88.4) years, 56% females received PT and were admitted for at least 5 days. Median total number of PT sessions was 15 (8; 24); median frequency was 5.2 sessions per week (3.0; 7.7); and duration was 27 (22; 34) minutes per session. Higher disease burden, cognitive impairment, delirium, higher anxiety and depression scores, malnutrition, frailty and sarcopenia were associated with a lower PT frequency. Older age, female sex, musculoskeletal reason for admission, greater independence in (instrumental) activities of daily living and handgrip strength were associated with a higher PT frequency.

CONCLUSIONS

PT frequency varied widely with a median of 1 session per working day. PT frequency was lowest in participants with poorest health characteristics.

Potentials of Acetylcholinesterase and Butyrylcholinesterase Alterations in On-Pump Coronary Artery Bypass Surgery in Postoperative Delirium: An Observational Trial

Cardiac surgery is regularly associated with postoperative delirium (POD), affected by neuro-inflammation and changes in cholinergic activity. Therefore, this prospective observational study aimed to evaluate whether pre- and perioperative changes in blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity were associated with POD development in patients undergoing isolated elective coronary artery bypass graft (CABG) surgery. It included 93 patients. Pre- and postoperative blood AChE and BChE activities were measured with photometric rapid-point-of-care-testing. The Intensive Care Delirium Screening Checklist and the Confusion Assessment Method for the Intensive Care Unit were used to screen patients for POD. POD developed in 20 patients (21.5%), who were older (p = 0.003), had higher EuroSCOREs (p ≤ 0.001), and had longer intensive care unit stays (p < 0.001). On postoperative day one, BChE activity decreased from preoperative values more in patients with (31.9%) than without (23.7%) POD (group difference p = 0.002). Applying a cutoff of ≥32.0% for BChE activity changes, receiver operating characteristic analysis demonstrated a moderate prediction capability for POD (area under the curve = 0.72, p = 0.002). The risk of developing POD was 4.31 times higher with a BChE activity change of ≥32.0% (p = 0.010). Monitoring the pre- to postoperative reduction in BChE activity might be a clinically practicable biomarker for detecting patients at risk of developing POD after CABG surgery.

Meta-analysis of serological biomarkers at hospital admission for the likelihood of developing delirium during hospitalization

Importance

Identifying biomarkers that, at hospital admission, predict subsequent delirium will help to focus our clinical efforts on prevention and management.

Objective

The study aimed to investigate biomarkers at hospital admission that may be associated with delirium during hospitalization.

Data sources

A librarian at the Fraser Health Authority Health Sciences Library performed searches from 28 June 2021 to 9 July 2021, using the following sources: Medline, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, and the Database of Abstracts of Reviews and Effects.

Study selection

The inclusion criteria were articles in English that investigated the link between serum concentration of biomarkers at hospital admission and delirium during hospitalization. Exclusion criteria were single case reports, case series, comments, editorials, letters to the editor, articles that were not relevant to the review objective, and articles concerning pediatrics. After excluding duplicates, 55 studies were included.

Data extraction and synthesis

This meta-analysis followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol. Independent extraction, with the consensus of multiple reviewers, was used to determine the final studies included. The weight and heterogeneity of the manuscripts were calculated using inverse covariance with a random-effects model.

Main outcomes and measures

Differences in mean serum concentration of biomarkers at hospital admission between patients who did and did not develop delirium during hospitalization.

Results

Our search found evidence that patients who developed delirium during hospitalization had, at hospital admission, significantly greater concentrations of certain inflammatory biomarkers and one blood-brain barrier leakage marker than patients who did not develop delirium during hospitalization (differences in the mean: cortisol: 3.36 ng/ml, p < 0.0001; CRP: 41.39 mg/L, p < 0.00001; IL-6: 24.05 pg/ml, p < 0.00001; S100β 0.07 ng/ml, p < 0.00001). These differences were independent of other confounding variables such as the patient's severity of illness. A significantly lower serum concentration, at hospital admission, of acetylcholinesterase (difference in the means -0.86 U/ml, p = 0.004) was also associated with an increased vulnerability to developing delirium during hospitalization.

Conclusion and relevance

Our meta-analysis supports the hypothesis that patients with hypothalamic-pituitary axis dysfunction, increased blood-brain barrier permeability, and chronic overload of the cholinergic system, at hospital admission, are more vulnerable to developing delirium during hospitalization.

Independent External Validation of a Preoperative Prediction Model for Delirium After Cardiac Surgery: A Prospective Observational Cohort Study

OBJECTIVE

This investigation provided independent external validation of an existing preoperative risk prediction model.

DESIGN

A prospective observational cohort study of patients undergoing cardiac surgery covering the period between April 16, 2018 and January 18, 2022.

SETTING

Two academic hospitals in Switzerland.

PARTICIPANTS

Adult patients (≥60 years of age) who underwent elective cardiac surgery, including coronary artery bypass graft, mitral or aortic valve replacement or repair, and combined procedures.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was the incidence of postoperative delirium (POD) in the intensive or intermediate care unit, diagnosed using the Intensive Care Delirium Screening Checklist. The prediction model contained 4 preoperative risk factors to which the following points were assigned: Mini-Mental State Examination (MMSE) score ≤23 received 2 points; MMSE 24-27, Geriatric Depression Scale (GDS) >4, prior stroke and/or transient ischemic attack (TIA), and abnormal serum albumin (≤3.5 or ≥4.5 g/dL) received 1 point each. The missing data were handled using multiple imputation. In total, 348 patients were included in the study. Sixty patients (17.4%) developed POD. For point levels in the prediction model of 0, 1, 2, and ≥3, the cumulative incidence of POD was 12.6%, 22.8%, 25.8%, and 35%, respectively. The validation resulted in a pooled area under the receiver operating characteristics curve of 0.60 (median CI, 0.525-0.679).

CONCLUSIONS

The evaluated predictive model for delirium after cardiac surgery in this patient cohort showed only poor discriminative capacity but fair calibration.

Protocol for the electroencephalography guidance of anesthesia to alleviate geriatric syndromes (ENGAGES-Canada) study: A pragmatic, randomized clinical trial

Background:  There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery.  There is limited evidence in this regard for cardiac surgery.  A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death.  However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods:  The Electroe ncephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes ( ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites.  The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery.  One approach is based on current standard anesthetic practice and the other on electroencephalography guidance to reduce POD. In the guided arm, clinicians are encouraged to decrease anesthetic administration, primarily if there is electroencephalogram suppression and secondarily if the EEG index is lower than the manufacturers recommended value (bispectral index (BIS) or WAVcns below 40 or Patient State Index below 25).  The aim in the guided group is to administer the minimum concentration of anesthetic considered safe for individual patients.  The primary outcome of the study is the incidence of POD, detected using the confusion assessment method or the confusion assessment method for the intensive care unit; coupled with structured delirium chart review.  Secondary outcomes include unexpected intraoperative movement, awareness, length of intensive care unit and hospital stay, delirium severity and duration, quality of life, falls, and predictors and outcomes of perioperative distress and dissociation. Discussion:  The ENGAGES-Canada trial will help to clarify whether or not using the electroencephalogram to guide anesthetic administration during cardiac surgery decreases the incidence, severity, and duration of POD. Registration: ClinicalTrials.gov ( NCT02692300) 26/02/2016.

Protocol for the electroencephalography guidance of anesthesia to alleviate geriatric syndromes (ENGAGES-Canada) study: A pragmatic, randomized clinical trial

Background:  There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery.  There is limited evidence in this regard for cardiac surgery.  A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death.  However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods:  The Electroe ncephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes ( ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites.  The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery.  One approach is based on current standard anesthetic practice and the other on electroencephalography guidance to reduce POD. In the guided arm, clinicians are encouraged to decrease anesthetic administration, primarily if there is electroencephalogram suppression and secondarily if the EEG index is lower than the manufacturers recommended value (bispectral index (BIS) or WAVcns below 40 or Patient State Index below 25).  The aim in the guided group is to administer the minimum concentration of anesthetic considered safe for individual patients.  The primary outcome of the study is the incidence of POD, detected using the confusion assessment method or the confusion assessment method for the intensive care unit; coupled with structured delirium chart review.  Secondary outcomes include unexpected intraoperative movement, awareness, length of intensive care unit and hospital stay, delirium severity and duration, quality of life, falls, and predictors and outcomes of perioperative distress and dissociation. Discussion:  The ENGAGES-Canada trial will help to clarify whether or not using the electroencephalogram to guide anesthetic administration during cardiac surgery decreases the incidence, severity, and duration of POD. Registration: ClinicalTrials.gov ( NCT02692300) 26/02/2016.

Correlation Analysis of Inflammatory Markers CRP and IL-6 and Postoperative Delirium (POD) in Elderly Patients: A Meta-Analysis of Observational Studies

Background

Postoperative delirium (POD) is very common in the elderly surgical population, and its occurrence is associated with multiple factors such as preoperative, intraoperative, and postoperative factors, and the increase of serum inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) is considered to be associated with the occurrence of POD, but the results of multiple studies are inconsistent. In this study, we investigated the correlation between inflammatory markers CRP and IL-6 and POD in elderly patients by literature search and meta-analysis.

Methods

We searched PubMed, Web of Science, the Cochrane library, Embase, Ovid, and Springer Link for cohort studies or case-control studies that investigated the factors involved in the occurrence of POD, used the Newcastle-Ottawa Scale (NOS) to assess the quality of the selected literature, and combined the differences in serum CRP and IL-6 levels between POD and non-POD patients after surgery to evaluate the predictive value of CRP and IL-6 for the occurrence of POD.

Results

This research comprised 16 papers for quantitative analysis, with a total of 2967 patients, 758 with POD and 2209 with non-POD. There were 16 cohort studies (100%) and 0 case-control studies (0%) across all the collected literatures; there were 15 prospective cohort studies and 1 retrospective cohort research. A meta-analysis revealed a statistically significant difference in serum IL-6 levels between POD patients after surgery and non-POD patients [MD = 115.68, 95% CI (25.70, 206.66), Z = 2.52, P = 0.012], as well as a statistically significant difference in serum CRP levels [MD = 27.67, 95% CI (12.77, 42.58), Z = 3.64, P = 0.0003]. Discussion. Early after surgery, serum IL-6 and CRP levels were considerably higher in POD patients than in non-POD patients, indicating that early serum inflammatory variables are likely to be predictors of POD. After surgery, the levels of the aforementioned inflammatory factors should be actively monitored to forecast the emergence of delirium, and active treatment should be used to limit the creation and release of the aforementioned inflammatory factors.

Risk factors for postoperative delirium after cardiac surgical procedures with cardioplegic arrest

OBJECTIVES

The pathophysiology of delirium after cardiac surgery is complex. The present study aims to determine perioperative risk factors and construct a scoring system for postoperative delirium based on the type of surgery.

METHODS

Three hundred patients undergoing coronary artery bypass grafting (CABG; n = 150) or valve and/or aortic surgery ± CABG (n = 150) were retrospectively evaluated.

RESULTS

The incidence of delirium (32%) was similar in subgroups (28.7% and 33.33%, P = 0.384). Delirium patients were older [71.3 (standard deviation: 8.5) vs 66.6 (standard deviation: 9.5), P < 0.001; 70.0 (standard deviation: 9.6) vs 62.5 (standard deviation: 12.6), P < 0.001] and required more packed red blood cell units [2.1 (standard deviation: 2.1) vs 4.2 (standard deviation: 4.0), P < 0.001; 2.4 (standard deviation: 3.3) vs 5.4 (standard deviation: 5.9), P < 0.001] and fresh frozen plasma units [6.1 (standard deviation: 2.9) vs. 8.0 (standard deviation: 4.2), P < 0.001; 6.3 (standard deviation: 3.4) vs 10.8 (standard deviation: 7.2), P < 0.001] in CABG and valve/aortic subgroups, respectively. Delirium was associated with longer operation time [298.3 (standard deviation: 98.4) vs 250.6 (standard deviation: 67.8) min, P < 0.001], cardiopulmonary bypass (CPB) time [171.5 (standard deviation: 54.9) vs 140.98 (standard deviation: 45.8) min, P < 0.001] and cardiac arrest time [112 (standard deviation: 35.9) vs 91.9 (standard deviation: 28.6), P < 0.001] only in the valve/aortic group (versus non-delirium). Multivariate regression analysis identified an association between delirium and age [odds ratio: 1.056 (95% confidence interval: 1.002-1.113), P = 0.041], CPB time [odds ratio: 1.1014 (95% confidence interval: 1.004-1.025), P = 0.007], fresh frozen plasma transfusion [odds ratio: 1.127 (95% confidence interval: 1.006-1.262), P = 0.039] and atrial fibrillation [odds ratio: 4.801 (95% confidence interval: 1.844-12.502), P < 0.001] after valve/aortic surgery (area under the curve 0.835, P < 0.001) and between delirium and age [odds ratio: 1.089 (95% confidence interval: 1.023-1.160), P = 0.007] and ventilation time [odds ratio: 1.068 (95% confidence interval: 1.026-1.113), P = 0.001] after isolated CABG (area under the curve 0.798, P < 0.001). The cross-validation of the results by k-fold logistic regression revealed for the entire patient cohort an overall average accuracy of the prediction model of 0.764, with a false-positive rate of 0.052 and a false-negative rate of 0.18.

CONCLUSIONS

Age, CPB time, ventilation, transfusion and atrial fibrillation are differently associated with delirium depending on the operative characteristics. Optimization of intraoperative parameters and use of risk calculators may enable early institution of pharmacotherapy and improve overall outcome after cardiac surgery.

Postoperative delirium and its relationship with biomarkers for dementia: a meta-analysis

OBJECTIVES

This study seeks to identify Alzheimer's and related dementias (ADRD) biomarkers associated with postoperative delirium (POD) via meta-analysis.

DESIGN

A comprehensive search was conducted. Studies met the following inclusion criteria: >18 years of age, identified POD with standardized assessment, and biomarker measured in the AT(N)-X (A = amyloid, T = tau, (N)=neurodegeneration, X-Other) framework. Exclusion criteria: focus on prediction of delirium, delirium superimposed on dementia, other neurologic or psychiatric disorders, or terminal delirium. Reviewers extracted and synthesized data for the meta-analysis.

SETTING

Meta-analysis.

PARTICIPANTS

Patients with POD.

MEASUREMENTS

Primary outcome: association between POD and ATN-X biomarkers. Secondary outcomes involved sample heterogeneity.

RESULTS

28 studies were included in this meta-analysis. Studies focused on inflammatory and neuronal injury biomarkers; there were an insufficient number of studies for amyloid and tau biomarker analysis. Two inflammatory biomarkers (IL-6, and CRP) showed a significant relationship with POD (IL-6 n = 10, standardized mean difference (SMD): 0.53, 95% CI: 0.36-0.70; CRP n = 14, SMD: 0.53, 95% CI: 0.33-0.74). Two neuronal injury biomarkers (blood-based S100B and NfL) were positively associated with POD (S100B n = 5, SMD: 0.40, 95% CI: 0.11-0.69; NFL n = 2, SMD: 0.93, 95% CI: 0.28-1.57). Of note, many analyses were impacted by significant study heterogeneity.

CONCLUSIONS

This meta-analysis identified an association between certain inflammatory and neuronal injury biomarkers and POD. Future studies will need to corroborate these relationships and include amyloid and tau biomarkers in order to better understand the relationship between POD and ADRD.

Postoperative delirium after cardiac surgery of elderly patients as an independent risk factor for prolonged length of stay in intensive care unit and in hospital

Background

Postoperative delirium (POD) is a relevant and underdiagnosed complication after cardiac surgery that is associated with increased intensive care unit (ICU) and hospital length of stay (LOS). The aim of this subgroup study was to compare the frequency of tested POD versus the coded International Statistical Classification of Diseases and Related Health Problems (ICD) diagnosis of POD and to evaluate the influence of POD on LOS in ICU and hospital.

Methods

254 elective cardiac surgery patients (mean age, 70.5 ± 6.4 years) at the University Hospital Bonn between September 2018 and October 2019 were evaluated. The endpoint tested POD was considered positive, if one of the tests Confusion Assessment Method for ICU (CAM-ICU) or Confusion Assessment Method (CAM), 4 'A's Test (4AT) or Delirium Observation Scale (DOS) was positive on one day.

Results

POD occurred in 127 patients (50.0%). LOS in ICU and hospital were significantly different based on presence (ICU 165.0 ± 362.7 h; Hospital 26.5 ± 26.1 days) or absence (ICU 64.5 ± 79.4 h; Hospital 14.6 ± 6.7 days) of POD (p < 0.001). The multiple linear regression showed POD as an independent predictor for a prolonged LOS in ICU (48%; 95%CI 31–67%) and in hospital (64%; 95%CI 27–110%) (p < 0.001). The frequency of POD in the study participants that was coded with the ICD F05.0 and F05.8 by hospital staff was considerably lower than tests revealed by the study personnel.

Conclusion

Approximately 50% of elderly patients who underwent cardiac surgery developed POD, which is associated with an increased ICU and hospital LOS. Furthermore, POD is highly underdiagnosed in clinical routine.

Prevalence of postoperative delirium with different combinations of intraoperative general anesthetic agents in patients undergoing cardiac surgery: A retrospective propensity-score-matched study

Postoperative delirium (PD) remains an issue in cardiac surgery despite the constant efforts to reduce its incidence. In this retrospective study, the incidence of PD was evaluated in patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) according to different primary anesthetic agents: sevoflurane and dexmedetomidine- versus propofol-based anesthesia.A total of 534 patients who underwent heart-valve surgery or coronary artery bypass graft surgery with CPB between January 2012 and August 2017 were divided into 2 groups according to the main anesthetic agent: sevoflurane with dexmedetomidine (sevo-dex group, n = 340) and propofol (propofol group, n = 194). The incidence of PD was evaluated as the primary outcome. Patient-, surgery-, and anesthesia-related factors and postoperative complications were investigated as secondary outcomes. To reduce the risk of confounding effects between the 2 groups, 194 patients were selected from the sevo-dex group after propensity-score matching.After propensity-score matching, the incidence of PD was not significantly different between the sevo-dex (6.2%) and propofol (10.8%) groups (P = .136). In comparisons of the incidence of each type of PD, only hyperactive PD occurred significantly less frequently in the sevo-dex group (P = .021). Older age, lower preoperative albumin levels, and emergency surgery were significant risk factors for PD.The overall incidence of PD after cardiac surgery with CPB did not differ between patients receiving sevoflurane and dexmedetomidine-based versus propofol-based anesthesia. Only hyperactive PD occurred less frequently in patients receiving sevoflurane and dexmedetomidine-based anesthesia.

Perioperative Vascular Biomarker Profiling in Elective Surgery Patients Developing Postoperative Delirium: A Prospective Cohort Study

Background: Postoperative delirium (POD) ranks among the most common complications in surgical patients. Blood-based biomarkers might help identify the patient at risk. This study aimed to assess how serum biomarkers with specificity for vascular and endothelial function and for inflammation are altered, prior to or following surgery in patients who subsequently develop POD. Methods: This was a study on a subcohort of consecutively recruited elective non-cardiac as well as cardiac surgery patients (age > 60 years) of the single-center PROPDESC trial at a German tertiary care hospital. Serum was sampled prior to and following surgery, and the samples were subjected to bead-based multiplex analysis of 17 serum proteins (IL-3, IL-8, IL-10, Cripto, CCL2, RAGE, Resistin, ANGPT2, TIE2, Thrombomodulin, Syndecan-1, E-Selectin, VCAM-1, ICAM-1, CXCL5, NSE, and uPAR). Development of POD was assessed during the first five days after surgery, using the Confusion Assessment Method for ICU (CAM-ICU), the CAM, the 4-‘A’s test (4AT), and the Delirium Observation Scale (DOS). Patients were considered positive if POD was detected at least once during the visitation period by any of the applied methods. Non-parametric testing, as well as propensity score matching were used for statistical analysis. Results: A total of 118 patients were included in the final analysis; 69% underwent non-cardiac surgery, median overall patient age was 71 years, and 59% of patients were male. In the whole cohort, incidence of POD was 28%. The male gender was significantly associated with the development of POD (p = 0.0004), as well as a higher ASA status III (p = 0.04). Incidence of POD was furthermore significantly increased in cardiac surgery patients (p = 0.002). Surgery induced highly significant changes in serum levels of almost all biomarkers except uPAR. In preoperative serum samples, none of the analyzed parameters was significantly altered in subsequent POD patients. In postoperative samples, CCL2 was significantly increased by a factor of 1.75 in POD patients (p = 0.03), as compared to the no-POD cohort. Following propensity score matching, CCL2 remained the only biomarker that showed significant differences in postoperative values (p = 0.01). In cardiac surgery patients, postoperative CCL2 serum levels were more than 3.5 times higher than those following non-cardiac surgery (p < 0.0001). Moreover, after cardiac surgery, Syndecan-1 serum levels were significantly increased in POD patients, as compared to no-POD cardiac surgery patients (p = 0.04). Conclusions: In a mixed cohort of elective non-cardiac as well as cardiac surgery patients, preoperative serum biomarker profiling with specificity for vascular dysfunction and for systemic inflammation was not indicative of subsequent POD development. Surgery-induced systemic inflammation—as evidenced by the significant increase in CCL2 release—was associated with POD, particularly following cardiac surgery. In those patients, postoperative glycocalyx injury might furthermore contribute to POD development.

The economic cost of delirium: A systematic review and quality assessment

INTRODUCTION

This review aims to systematically identify and appraise the methodological quality of claims on the cost of delirium; and discuss challenges and opportunities for improvements in the precision of the estimates.

METHODS

Searches of scientific papers and gray literature were performed up until June 2020. The Larg and Moss checklist was used to assess the methodological quality of the included studies.

RESULTS

After deduplication, the search identified 317 potentially relevant articles, of which 17 articles were eligible for inclusion. After adjusting for inflation and common currency, the cost of delirium ranged between $806 and $24,509 (in 2019 US$).

DISCUSSION

This review found significant variation among the cost estimates and methodological quality. There has been limited focus on dementia as a sequela of delirium in terms of economic implications, but recent evidence suggests cost implications of delirium may be 52% higher when dementia is considered.

Elevated Procalcitonin as a Risk Factor for Postoperative Delirium in the Elderly after Cardiac Surgery-A Prospective Observational Study

One of the most common complications after cardiac surgery with cardiopulmonary bypass (CBP) is delirium. The purpose of this study was to prospectively investigate the risk of developing postoperative delirium in a group of elderly patients using a multivariate assessment of preoperative and intraoperative risk factors. A total of 149 elderly patients were included. Thirty patients (20%) developed post-operative delirium. Preoperative procalcitonin (PCT) above the reference range (>0.05 ng/mL) was recorded more often in patients who postoperatively developed delirium than in the non-delirium group (50% vs. 27%, p = 0.019). After surgery, PCT was significantly higher in the delirium than the non-delirium group: ICU admission after surgery: 0.08 ng/mL vs. 0.05 ng/mL p = 0.011), and for consecutive days (day 1: 0.59 ng/mL vs. 0.25 ng/mL, p = 0.003; day 2: 1.21 ng/mL vs. 0.36 ng/mL, p = 0.006; day 3: 0.76 ng/mL vs. 0.34 ng/mL, p = 0.001). Patients with delirium were older (74 vs. 69 years, p = 0.038), more often had impaired daily functioning (47% vs. 28%, p = 0.041), depressive symptoms (40% vs. 17%, p = 0.005), and anemia (43% vs. 19%, p = 0.006). In a multivariable logistic regression model, preoperative procalcitonin (odds ratio (OR) = 3.05), depressive symptoms (OR = 5.02), age (OR = 1.14), impaired daily functioning (OR = 0.76) along with CPB time (OR = 1.04) were significant predictors of postoperative delirium.

Preoperative prognostic nutritional index predicts postoperative delirium in elderly patients after hip fracture surgery

BACKGROUND

Postoperative delirium (POD) is a very common complication in elderly patients after hip fracture surgery, which has poorly understood pathophysiology. This study aimed to investigate potential risk factors for POD.

METHODS

Elderly patients (aged ≥65 years) scheduled to undergo selective surgery in our hospital were consecutively recruited. Patient characteristics, preoperative laboratory tests and prognostic nutritional index (PNI) levels were compared between patients with or without POD. The risk factors for POD were evaluated by univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive value of PNI and age for POD.

RESULTS

Fifty-seven of the 163 enrolled patient had suffered POD within postoperative day 7 with an incidence of 35.0%. Multivariate logistic analyses revealed that an advanced age (cut-off value: 71.5 years, sensitivity: 48.1%, specificity: 75.4%, odds ratio (OR): 3.24, 95% CI: 1.16-8.69, P = 0.026) and lower PNI level (cut-off value: 47.45, sensitivity: 86.0%, specificity: 51.9%, OR: 2.88, 95% CI: 1.25-6.64, P = 0.012) were two independent predictive factors associated with POD. According to the ROC curve analysis, preoperative PNI level was a predictor for POD with an area under the curve of 0.686 (95% CI: 0.604-0.767, P < 0.001).

CONCLUSIONS

Advanced age and lower preoperative PNI level were significantly associated with POD in elderly patients after hip fracture surgery.

Preoperative Circulating MiR-210, a Risk Factor for Postoperative Delirium Among Elderly Patients with Gastric Cancer Undergoing Curative Resection

BACKGROUND

Postoperative delirium (POD) is a very common complication in elderly patients with gastric cancer (GC) and associated with poor prognosis. MicroRNAs (miRNAs) serve as key post-transcriptional regulators of gene expression via targeting mRNAs and play important roles in the nervous system. This study aimed to investigate the potential predictive role of miRNAs for POD.

METHODS

Elderly GC patients who were scheduled to undergo elective curative resection were consequently enrolled in this study. POD was assessed at 1 day before surgery and 1-7 days after surgery following the guidance of the 5th edition of Diagnostic and Statistical Manual of Mental Disorders (DSM V, 2013). The demographics, clinicopathologic characteristics and preoperative circulating miRNAs by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were compared between patients with or without POD. Risk factors for POD were assessed via univariate and multivariate logistic regression analyses.

RESULTS

A total of 370 participants were enrolled, of which 63 had suffered from POD within postoperative 7 days with an incidence of 17.0%. Preoperative miR-210 was a predictor for POD with an area under the curve (AUC) of 0.921, a cut-off value of 1.67, a sensitivity of 95.11%, and a specificity of 92.06%, (P<0.001). In the multivariate logistic regression model, the relative expression of serum miR-210 was an independent risk factor for POD (OR: 3.37, 95%CI: 1.98-5.87, P=0.003).

CONCLUSIONS

In conclusion, the present study highlighted that preoperative miR-210 could serve as a potential predictor for POD in elderly GC patients undergoing curative resection.

The Incidence and Predictors of Postoperative Delirium After Brain Tumor Resection in Adults: A Cross-Sectional Survey

BACKGROUND

Postoperative delirium (POD) describes a multifactorial disease process occurring after surgery. However, few studies have focused on patients undergoing brain tumor resection, and its influencing factors are unclear.

METHODS

We performed a 1-year, single-center, cross-sectional, retrospective survey at Huashan Hospital. Patients were screened using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), Confusion Assessment Method, and Richmond Agitation Sedation Scale by trained bedside nurses. Perioperative data were collected using demographic and disease-related questionnaires. The primary outcome measures were the incidence of POD and subtype of POD. Independent predictors of POD were estimated from multivariate logistic regression models, and receiver operating characteristic analysis was used to compare the predictive performance of the models.

RESULTS

Of the 916 patients included in the study, 893 were analyzed. The overall incidence was 14.78%, 67 had hyperactive delirium (50.76%), 55 had hypoactive delirium (41.67%), and 10 had mixed delirium (7.57%). Age, sex, working status, tobacco use history, comorbidities, physical restraint, axillary temperature (>38.5°C), electrolyte disturbances, duration of anesthesia, pathologic diagnosis, tumor site, length of disease, and duration of operation were risk factors for POD. Conversely, saddle area mass was a protective factor. Age, tobacco use history, electrolyte disturbances, physical restraint, and duration of operation were included in the model.

CONCLUSIONS

POD is harmful to patients undergoing brain tumor resection, increasing length of stay in the intensive care unit and hospitalization costs. Intraoperative factors and postoperative factors, in addition to older age and tobacco use history, are associated with POD.

Postoperative Serum Albumin Decrease Independently Predicts Delirium in the Elderly Subjects after Total Joint Arthroplasty

Background:

Postoperative delirium (POD), a neurobehavioral syndrome induced by dysfunction of neural activity, is a common and serious complication. This current study aimed to investigate independent predictors for POD in elderly subjects after total joint arthroplasty (TJA).

Methods:

Eligible elderly patients (≥65 years) who underwent elective unilateral primary hip or knee arthroplasty under epidural anesthesia from October 2016 to January 2019 were consecutively enrolled. POD was diagnosed following the guidance of the 5th edition of Diagnostic and Statistical Manual of Mental Disorders, (DSM V, 2013). The relative change in serum Alb (ΔAlb) was defined as the absolute value of (preoperative Alb value– nadir value within postoperative day 2)/preoperative Alb ×100%. The predictive value of ΔAlb for POD was evaluated by receiver operating characteristic (ROC) curve analysis. Univariate and multivariate logistic regression analyses were used for evaluating risk factors for POD.

Results:

A total of 328 patients were enrolled in the analysis, of which 68 (20.7%, 68/328) patients developed POD within postoperative 7 days. ΔAlb was an effective predictor for POD with an area under the curve (AUC) of 0.821, a sensitivity of 76.15% and a specificity of 70.59%, respectively (P<0.001). Univariate and multivariate logistic regression analyses indicated that ΔAlb was the only independent risk factor for POD (OR: 2.43, 95%CI: 1.17–4.86, P=0.015).

Conclusions:

ΔAlb was an independent risk factor for POD in elderly subjects after TJA.

The pharmacotherapeutic management of postoperative delirium: an expert update

INTRODUCTION

Postoperative delirium is a common sequela in older adults in the peri-operative period leading to poor outcomes with a complex pathophysiology which has led to a variety of different pharmacologic agents employed in attempts to prevent and treat this syndrome. No pharmacologic agent has been approved to treat this disorder, but this review discusses the pharmacologic strategies which have been tried based on the hypotheses of the causation of the syndrome including neurotransmitter imbalance, inflammation, and oxidative stress.

AREAS COVERED

Systematic reviews and meta-analyses of randomized clinical trials (RCTs) were included via search of electronic databases specifically for the terms postoperative delirium and pharmacologic treatments. With this approach, the recurrent topics of analgesia and sedation, antipsychotics, acetylcholinesterase inhibitors (AchE-Is), inflammation, and melatonin were emphasized and provided the outline for this review.

EXPERT OPINION

Research evidence does not support any particular agent in any of the pharmacologic classes reviewed. However, there is some potential benefit with dexmedetomidine, melatonin, and the monitoring of anesthetic agents all of which need further clinical trials to validate these conclusions. Exploration of ways to improve studies and the application of novel pharmacologic agents may offer future benefit.

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.

Atypical Sleep and Postoperative Delirium in the Cardiothoracic Surgical Intensive Care Unit: A Pilot Prospective Study

PURPOSE

Postoperative delirium (POD) is a very common and serious neurological complication in patients admitted to the cardiothoracic surgical intensive care unit (CSICU). We aimed to identify a novel potential sleep-based marker for POD and investigate the relevance between atypical sleep and POD.

PATIENTS AND METHODS

This was a prospective, observational study of patients admitted to the CSICU between December 2019 and February 2020 at our center. Sleep characteristics from 21:00 on postoperative day 1 to 07:00 on postoperative day 2 were assessed using polysomnography (PSG). POD from the end of PSG monitoring until postoperative day 5 was evaluated using the Confusion Assessment Method for the Intensive Care Unit.

RESULTS

This analysis included 20 patients admitted to the CSICU. The incidence of atypical sleep was 45.0%. Compared to patients without delirium, those with delirium had less delta power, less percentage REM sleep, and a higher proportion of atypical sleep and REM sleep loss (P < 0.05).

CONCLUSION

The presence of atypical sleep and the absence of REM sleep were associated with POD in patients admitted to the CSICU.

Delirium post-cardiac surgery: Incidence and associated factors

BACKGROUND

Post-operative delirium among cardiac surgery patients is a prevalent complication that associated with multiple negative outcomes.

AIM

This study aimed to assess delirium incidence, associated factors, and outcomes for adult patients who underwent elective cardiac surgery.

DESIGN

An exploratory prospective cohort design was used for this study.

METHODS

Delirium was diagnosed by the Confusion Assessment Method for the Intensive Care Unit. Incidence, preoperative, intraoperative, and post-operative variables for 245 patients during 3-month period were collected and analysed.

RESULTS

Delirium developed in 9% (n = 22) of the sample. Patients with delirium were significantly older (mean age = 65.7, SD = 8.1), t (243) = -3.66, P < .05); had longer surgery time (mean time = 286.3, SD = 82.2), t (243) = -2.25, P < .05); received more blood post-surgery (t (243) = -3.86, P < .05); spent more time on mechanical ventilation (t [21.6] = -2.2, P < .05); had longer critical care unit stay (t [21.7] = -4.0, P < 0.05); and had longer hospitalization than patients without delirium.

CONCLUSIONS

The risk factors associated with development of delirium were advanced age and increased duration of surgery. Negative outcomes associated with delirium were increased duration of mechanical ventilation, increased volume of post-operative infused colloids and blood/products, increased critical care unit stay, and increased hospitalization. A multifactorial model for delirium risk factors should be considered to detect and work on potentially preventable delirium factors.

RELEVANCE TO CLINICAL PRACTICE

Post-cardiac surgery delirium leads to longer mechanical ventilation time, increased ICU stay, and prolonged hospitalization. Delirium post-cardiac surgery is potentially preventable with appropriate identification of risk factors by nurses.

Development and validation of a postoperative delirium prediction model for patients admitted to an intensive care unit in China: a prospective study

OBJECTIVES

We aimed to develop and validate a postoperative delirium (POD) prediction model for patients admitted to the intensive care unit (ICU).

DESIGN

A prospective study was conducted.

SETTING

The study was conducted in the surgical, cardiovascular surgical and trauma surgical ICUs of an affiliated hospital of a medical university in Heilongjiang Province, China.

PARTICIPANTS

This study included 400 patients (≥18 years old) admitted to the ICU after surgery.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was POD assessment during ICU stay.

RESULTS

The model was developed using 300 consecutive ICU patients and was validated using 100 patients from the same ICUs. The model was based on five risk factors: Physiological and Operative Severity Score for the enumeration of Mortality and morbidity; acid-base disturbance and history of coma, diabetes or hypertension. The model had an area under the receiver operating characteristics curve of 0.852 (95% CI 0.802 to 0.902), Youden index of 0.5789, sensitivity of 70.73% and specificity of 87.16%. The Hosmer-Lemeshow goodness of fit was 5.203 (p=0.736). At a cutoff value of 24.5%, the sensitivity and specificity were 71% and 69%, respectively.

CONCLUSIONS

The model, which used readily available data, exhibited high predictive value regarding risk of ICU-POD at admission. Use of this model may facilitate better implementation of preventive treatments and nursing measures.

C-reactive protein for risk prediction of post-operative delirium and post-operative neurocognitive disorder

BACKGROUND

Post-operative delirium (POD) and post-operative neurocognitive disorder (NCD) are frequently seen in the elderly. Development of biomarkers for pre-operative risk prediction is of major relevance. As inflammation present before surgery might predispose to POD and post-operative NCD development, we aim to determine associations between pre-operative C-reactive protein (CRP) and the incidence of POD and post-operative NCD.

METHODS

In this observational study, we analyzed 314 patients enrolled in the SuDoCo trial, who had a pre-operative CRP measurement the day before surgery. Primary outcomes were POD assessed according DSM-4 from day 1 until day 7 after surgery and post-operative NCD assessed 3 months after surgery. We conducted multivariable logistic regression analysis adjusted for age, sex, randomization, body mass index, MMSE, ASA status, infection/autoimmune disease/malignoma and types of surgery to determine associations between CRP with POD and post-operative NCD, respectively.

RESULTS

Pre-operative CRP was independently associated with POD [OR 1.158 (95% CI 1.040, 1.291); P = .008]. Patients with CRP values ≥5 mg/dL had a 4.8-fold increased POD risk [OR 4.771 (95% CI 1.765, 12.899; P = .002)] compared to patients with lower CRP values. However, no association was seen between pre-operative CRP and post-operative NCD [OR 0.552 (95% CI 0.193, 1.581); P = .269].

CONCLUSIONS

Pre-operative CRP levels were independently associated with POD but not post-operative NCD after three months. Moreover, higher pre-operative CRP levels showed higher risk for POD. This strengthens the role of inflammation in the development of POD. Assessment of CRP before surgery might allow risk stratification of POD.

TRIAL REGISTRATION

This study was registered with ISRCTN Register 36437985 on 02 March 2009.

Risk Factors for Postoperative Delirium in Type A Aortic Dissection Patients: A Retrospective Study

BACKGROUND Postoperative delirium (POD) is a common complication in cardiac surgery among adult patients. This retrospective study was designed to identify the risk factors associated with POD of type A aortic dissection patients. MATERIAL AND METHODS Clinical data of 148 patients with type A aortic dissection in the Department of Critical Care Medicine was retrospectively analyzed. All these patients underwent Sun's procedure with anesthetic treatment. The confusion assessment method for intensive care unit (CAM-ICU) was adapted to evaluate the delirium status of these patients. They were divided into 2 groups: the delirium group and the control group. Univariate analysis and multivariate logistic regression were performed in succession to determine the independent risk factors for POD. RESULTS The average age of these patients was 54.41±11.676 years old. Among the 148 patients, POD was detected in 68 patients, with an incidence of 45.95%. According to univariate analysis, age, irritability, alcohol use, extracorporeal circulation duration (cardiopulmonary bypass, CPB time), antegrade selective cerebral perfusion (ASCP) time, lowest partial pressure of oxygen (lowest PO2), mechanical ventilation time, blood loss, low PO₂ and oxygenation index, hemoglobin (Hb), Intensive Care Unit (ICU) stay, and dihydroxyphenylalanine (DEX) were associated with higher odds of POD among type A aortic dissection patients. According to further analysis of multivariate logistic regression, ASCP time and irritability were confirmed as the independent factors for POD of type A aortic dissection patients. CONCLUSIONS We determined 2 independent risk factors for POD: ASCP time and irritability. Identifying and adjusting these risk factors are very important in reducing the incidence of POD among type A aortic dissection patients.

Handover of anesthesia care is associated with an increased risk of delirium in elderly after major noncardiac surgery: results of a secondary analysis

In patients undergoing major surgery, complete handover of intraoperative anesthesia care is associated with adverse postoperative outcomes including high mortality and more major complications. The purpose of this study was to explore the association between the intraoperative complete handover between anesthesiologists and the occurrence of postoperative delirium. This was a secondary analysis of the database of a previously published clinical trial. Seven hundred patients aged 65 years or older, who were admitted to the intensive care unit after noncardiac surgery, were included. Delirium was assessed with the Confusion Assessment Method for the Intensive Care Unit twice daily during the first 7 postoperative days. Other postoperative outcomes were also monitored. The association between the intraoperative complete handover of anesthesia care and the development of postoperative delirium was analyzed with a logistic regression model. Of the 700 enrolled patients, 111 (15.9%) developed postoperative delirium within 7 days. After correction for confounding factors, intraoperative complete handover between anesthesiologists was associated with an increased risk of postoperative delirium (OR 1.787, 95% CI 1.012–3.155, P = 0.046). Patients with intraoperative complete handover also had higher incidence of non-delirium complications (P = 0.003) and stayed longer in hospital after surgery (P = 0.002). For elderly patients admitted to the intensive care unit after noncardiac surgery, intraoperative complete handover of anesthesia care was associated with an increased risk of postoperative delirium. Chinese Clinical Trial Registry (http://www.chictr.org.cn): ChiCTR-TRC-10000802.

Perioperative cognitive evaluation

PURPOSE OF REVIEW

This article reviews the recent clinical evidence published between January 2017 and June 2018 - related to perioperative cognitive evaluation. Namely, new insights into risk factors, prevention, diagnosis and diagnostic tools and treatment.

RECENT FINDINGS

Several risk factors (preoperative, intraoperative and postoperative) have been found to be associated with the development of postoperative delirium (POD) and/or postoperative cognitive dysfunction (POCD). Short-term and long-term postoperative consequences can be reduced by targeting risk factors, introducing preventive strategies and including frequent cognitive monitoring. Administration of medications such as ketamine, opioids and benzodiazepines are associated with increased cognitive dysfunction. Prevention of POD/POCD starts with creating an environment, which promotes return to preoperative baseline functioning. This includes frequent monitoring of cognitive status, access to rehabilitation and psychological and social supports, and avoiding polypharmacy. In addition, patients should have early access to their sensory aids and maintain normal circadian rhythm. Treatment of POD/POCD has pharmacological and nonpharmacological approaches.

SUMMARY

Clinical evidence on POD/POCD is continuously evolving, which is essential in guiding clinical management to provide the highest quality of clinical care.

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.

‘I hope you get normal again’: an explorative study on how delirious octogenarian patients experience their interactions with healthcare professionals and relatives after aortic valve therapy

Background:

Delirium affects nearly half of octogenarian patients after aortic valve replacement, resulting in impaired cognition, reduced awareness and hallucinations. Although healthcare professionals and relatives are often present during episodes, the nature of interactions with them is scarcely studied, and little is known about their long-term experiences.

Purpose:

The purpose of this study was to explore and describe how octogenarian patients with post-aortic valve replacement delirium experience interactions with healthcare professionals and relatives within the first year and four years later.

Method:

An explorative design with qualitative content analysis was used. Delirium was assessed for five consecutive days after aortic valve replacement using the Confusion Assessment Method. Delirious patients ( n=10) were interviewed 6–12 months post-discharge and four years later ( n=5). We used an inductive approach to identify themes in transcribed interviews.

Findings:

An overarching theme emerged: ‘ Healthcare professionals’ and relatives’ responses made a considerable impact on the delirium experience postoperatively and in a long-term’. Three sub-themes described the patients’ experiences: ‘ the need for close supportive care’, ‘ disrespectful behaviour created a barrier’ and ‘ insensitive comments made lasting impressions’. Having healthcare professionals and relatives nearby made the patients feel secure, while lack of attention elevated patients’ emotional distress. Four years later, patients clearly recalled negative comments and unsupportive actions in their delirious state.

Conclusions:

Healthcare professionals and relatives have an essential role in the aortic valve replacement recovery process. Inconsiderate behaviour directed at older patients in delirium elevates distress and has long-term implications. Supportive care focused on maintaining the patients’ dignity and integrity is vital.

Delirium after cardiac surgery. Incidence, phenotypes, predisposing and precipitating risk factors, and effects

BACKGROUND

In cardiac surgical patients little is known about different phenotypes of delirium and how the symptoms fluctuate over time.

OBJECTIVES

Evaluate risk factors, incidence, fluctuations, phenotypic characteristics and impact on patients' outcomes of delirium.

METHODS

Prospective longitudinal study. In postoperative intensive care unit 199 patient were assessed three-times a day through an adapted versions of the Intensive Care Delirium Screening Checklist.

RESULTS

Delirium and subsyndromal delirium incidence were 30.7% and 31.2%, respectively. Delirium manifested mostly in the hypoactive form and showed a fluctuating trend for several days. Atrial fibrillation, benzodiazepine/opioids dosages, hearing impairment, extracorporeal circulation length, SAPS-II and mean arterial pressure were independent predictors for delirium. Delirium was a statistically significant predictor of chemical/physical restraint use and hospital length of stay.

CONCLUSIONS

Given the fluctuating and phenotypic characteristics, delirium screening should be a systematic/intentional activity. Multidisciplinary prevention strategies should be implemented to identify and treat the modifiable risk factors.