Decreased Cerebrospinal Fluid Amyloid ß 38, 40, 42, and 43 Levels in Sporadic and Hereditary Cerebral Amyloid Angiopathy.

OBJECTIVE: Vascular amyloid ß (Aß) accumulation is the hallmark of cerebral amyloid angiopathy (CAA). The composition of cerebrospinal fluid (CSF) of CAA patients may serve as a diagnostic biomarker of CAA. We studied the diagnostic potential of the peptides Aß38, Aß40, Aß42, and Aß43 in patients with sporadic CAA (sCAA), hereditary Dutch-type CAA (D-CAA), and Alzheimer disease (AD). METHODS: Aß peptides were quantified by immunoassays in a discovery group (26 patients with sCAA and 40 controls), a validation group (40 patients with sCAA, 40 patients with AD, and 37 controls), and a group of 22 patients with D-CAA and 54 controls. To determine the diagnostic accuracy, the area under the curve (AUC) was calculated using a receiver operating characteristic curve with 95% confidence interval (CI). RESULTS: We found decreased levels of all Aß peptides in sCAA patients and D-CAA patients compared to controls. The difference was most prominent for Aß42 (AUC of sCAA vs controls for discovery: 0.90, 95% CI = 0.82-0.99; for validation: 0.94, 95% CI = 0.89-0.99) and Aß43 (AUC of sCAA vs controls for discovery: 0.95, 95% CI = 0.88-1.00; for validation: 0.91, 95% CI = 0.83-1.0). All Aß peptides except Aß43 were also decreased in sCAA compared to AD (CSF Aß38: AUC = 0.82, 95% CI = 0.71-0.93; CSF Aß40: AUC = 0.88, 95% CI = 0.80-0.96; CSF Aß42: AUC = 0.79, 95% CI = 0.66-0.92). INTERPRETATION: A combined biomarker panel of CSF Aß38, Aß40, Aß42, and Aß43 has potential to differentiate sCAA from AD and controls, and D-CAA from controls. ANN NEUROL 2023;93:1173-1186.

Predicting 30-day mortality in intensive care unit patients with ischaemic stroke or intracerebral haemorrhage.

BACKGROUND: Stroke patients admitted to an intensive care unit (ICU) follow a particular survival pattern with a high short-term mortality, but if they survive the first 30 days, a relatively favourable subsequent survival is observed. OBJECTIVES: The development and validation of two prognostic models predicting 30-day mortality for ICU patients with ischaemic stroke and for ICU patients with intracerebral haemorrhage (ICH), analysed separately, based on parameters readily available within 24 h after ICU admission, and with comparison with the existing Acute Physiology and Chronic Health Evaluation IV (APACHE-IV) model. DESIGN: Observational cohort study. SETTING: All 85 ICUs participating in the Dutch National Intensive Care Evaluation database. PATIENTS: All adult patients with ischaemic stroke or ICH admitted to these ICUs between 2010 and 2019. MAIN OUTCOME MEASURES: Models were developed using logistic regressions and compared with the existing APACHE-IV model. Predictive performance was assessed using ROC curves, calibration plots and Brier scores. RESULTS: We enrolled 14 303 patients with stroke admitted to ICU: 8422 with ischaemic stroke and 5881 with ICH. Thirty-day mortality was 27% in patients with ischaemic stroke and 41% in patients with ICH. Important factors predicting 30-day mortality in both ischaemic stroke and ICH were age, lowest Glasgow Coma Scale (GCS) score in the first 24 h, acute physiological disturbance (measured using the Acute Physiology Score) and the application of mechanical ventilation. Both prognostic models showed high discrimination with an AUC 0.85 [95% confidence interval (CI), 0.84 to 0.87] for patients with ischaemic stroke and 0.85 (0.83 to 0.86) in ICH. Calibration plots and Brier scores indicated an overall good fit and good predictive performance. The APACHE-IV model predicting 30-day mortality showed similar performance with an AUC of 0.86 (95% CI, 0.85 to 0.87) in ischaemic stroke and 0.87 (0.86 to 0.89) in ICH. CONCLUSION: We developed and validated two prognostic models for patients with ischaemic stroke and ICH separately with a high discrimination and good calibration to predict 30-day mortality within 24 h after ICU admission. TRIAL REGISTRATION: Trial registration: Dutch Trial Registry ( https://www.trialregister.nl/ ); identifier: NTR7438.

Risk of Dementia and Structural Brain Changes Following Nonneurological Infections During 9-Year Follow-Up.

OBJECTIVES: Given the strong association between systemic inflammation and cognitive decline, we aimed to determine whether nonneurologic infections are associated with accelerated cognitive decline and structural changes in the brain using pre- and post-infection neuropsychologic assessments and repeated brain MR images. DESIGN: Additional analysis of the prospective observational Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort study. SETTING: Single-center study at the Radboud university medical center, Nijmegen, The Netherlands, between January 2006 and September 2015. PATIENTS: Five-hundred three participants (50-85 yr old) with cerebral small vessel disease were included and followed for 9 years. MEASUREMENTS AND MAIN RESULTS: Participants underwent repeated cognitive measurements and brain MRI. Infectious events were collected. Sepsis episodes were analyzed, and additionally, patients were stratified in three groups: having had a severe infectious episode (e.g., sepsis or hospitalization for infection), a mild, or no infectious episode. Development of dementia, trajectories of cognition, and structural brain changes on MRI in the subsequent follow-up periods were compared between the groups. Complete infectious data were available from 331 patients (mean age 64 ± 8 yr, 57% males). Twenty-nine participants (9%) suffered from a sepsis episode, 69 (21%) from a severe, 201 (61%) from a mild, and 61 (18%) had no infectious episode during follow-up. After correction for age, baseline cognition, and brain volume, each sepsis episode remained associated with an 82% increased risk to develop dementia within the follow-up period (hazard ratio, 1.82; 95% CI, 1.07-3.10; p = 0.027). Infections had no effect on the trajectory of structural changes to the brain after correction for baseline differences. CONCLUSIONS: In this 9-year observational follow-up study, sepsis episodes were associated with subsequent development of dementia. Nonneurologic infections had no effect on the trajectory of structural cerebral changes.

Elevated expression of urokinase plasminogen activator in rodent models and patients with cerebral amyloid angiopathy.

AIMS: The aim of this work is to study the association of urokinase plasminogen activator (uPA) with development and progression of cerebral amyloid angiopathy (CAA). MATERIALS AND METHODS: We studied the expression of uPA mRNA by quantitative polymerase chain reaction (qPCR) and co-localisation of uPA with amyloid-ß (Aß) using immunohistochemistry in the cerebral vasculature of rTg-DI rats compared with wild-type (WT) rats and in a sporadic CAA (sCAA) patient and control subject using immunohistochemistry. Cerebrospinal fluid (CSF) uPA levels were measured in rTg-DI and WT rats and in two separate cohorts of sCAA and Dutch-type hereditary CAA (D-CAA) patients and controls, using enzyme-linked immunosorbent assays (ELISA). RESULTS: The presence of uPA was clearly detected in the cerebral vasculature of rTg-DI rats and an sCAA patient but not in WT rats or a non-CAA human control. uPA expression was highly co-localised with microvascular Aß deposits. In rTg-DI rats, uPA mRNA expression was highly elevated at 3 months of age (coinciding with the emergence of microvascular Aß deposition) and sustained up to 12 months of age (with severe microvascular CAA deposition) compared with WT rats. CSF uPA levels were elevated in rTg-DI rats compared with WT rats (p = 0.03), and in sCAA patients compared with controls (after adjustment for age of subjects, p = 0.05 and p = 0.03). No differences in CSF uPA levels were found between asymptomatic and symptomatic D-CAA patients and their respective controls (after age-adjustment, p = 0.09 and p = 0.44). Increased cerebrovascular expression of uPA in CAA correlates with increased quantities of CSF uPA in rTg-DI rats and human CAA patients, suggesting that uPA could serve as a biomarker for CAA.

Human in vivo neuroimaging to detect reprogramming of the cerebral immune response following repeated systemic inflammation.

Despite increasing evidence that immune training within the brain may affect the clinical course of neuropsychiatric diseases, data on cerebral immune tolerance are scarce. This study in healthy volunteers examined the trajectory of the immune response systemically and within the brain following repeated lipopolysaccharide (LPS) challenges. Five young males underwent experimental human endotoxemia (intravenous administration of 2 ng/kg LPS) twice with a 7-day interval. The systemic immune response was assessed by measuring plasma cytokine levels. Four positron emission tomography (PET) examinations, using the translocator protein (TSPO) ligand 18F-DPA-714, were performed in each participant, to assess brain immune cell activation prior to and 5 hours after both LPS challenges. The first LPS challenge caused a profound systemic inflammatory response and resulted in a 53% [95%CI 36-71%] increase in global cerebral 18F-DPA-714 binding (p < 0.0001). Six days after the first challenge, 18F-DPA-714 binding had returned to baseline levels (p = 0.399). While the second LPS challenge resulted in a less pronounced systemic inflammatory response (i.e. 77 ± 14% decrease in IL-6 compared to the first challenge), cerebral inflammation was not attenuated, but decreased below baseline, illustrated by a diffuse reduction of cerebral 18F-DPA-714 binding (-38% [95%CI -47 to -28%], p < 0.0001). Our findings constitute evidence for in vivo immunological reprogramming in the brain following a second inflammatory insult in healthy volunteers, which could represent a neuroprotective mechanism. These results pave the way for further studies on immunotolerance in the brain in patients with systemic inflammation-induced cerebral dysfunction.

Determining the impact of timing and of clinical factors during end-of-life decision-making in potential controlled donation after circulatory death donors.

Controlled donation after circulatory death (cDCD) occurs after a decision to withdraw life-sustaining treatment and subsequent family approach and approval for donation. We currently lack data on factors that impact the decision-making process on withdraw life-sustaining treatment and whether time from admission to family approach, influences family consent rates. Such insights could be important in improving the clinical practice of potential cDCD donors. In a prospective multicenter observational study, we evaluated the impact of timing and of the clinical factors during the end-of-life decision-making process in potential cDCD donors. Characteristics and medication use of 409 potential cDCD donors admitted to the intensive care units (ICUs) were assessed. End-of-life decision-making was made after a mean time of 97 hours after ICU admission and mostly during the day. Intracranial hemorrhage or ischemic stroke and a high APACHE IV score were associated with a short decision-making process. Preserved brainstem reflexes, high Glasgow Coma Scale scores, or cerebral infections were associated with longer time to decision-making. Our data also suggest that the organ donation request could be made shortly after the decision to stop active treatment and consent rates were not influenced by daytime or nighttime or by the duration of the ICU stay.

Long-Term Mortality Among ICU Patients With Stroke Compared With Other Critically Ill Patients.

OBJECTIVES: Assessment of all-cause mortality of intracerebral hemorrhage and ischemic stroke patients admitted to the ICU and comparison to the mortality of other critically ill ICU patients classified into six other diagnostic subgroups and the general Dutch population. DESIGN: Observational cohort study. SETTING: All ICUs participating in the Dutch National Intensive Care Evaluation database. PATIENTS: All adult patients admitted to these ICUs between 2010 and 2015; patients were followed until February 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of all 370,386 included ICU patients, 7,046 (1.9%) were stroke patients, 4,072 with ischemic stroke, and 2,974 with intracerebral hemorrhage. Short-term mortality in ICU-admitted stroke patients was high with 30 days mortality of 31% in ischemic stroke and 42% in intracerebral hemorrhage. In the longer term, the survival curve gradient among ischemic stroke and intracerebral hemorrhage patients stabilized. The gradual alteration of mortality risk after ICU admission was assessed using left-truncation with increasing minimum survival period. ICU-admitted stroke patients who survive the first 30 days after suffering from a stroke had a favorable subsequent survival compared with other diseases necessitating ICU admission such as patients admitted due to sepsis or severe community-acquired pneumonia. After having survived the first 3 months after ICU admission, multivariable Cox regression analyses showed that case-mix adjusted hazard ratios during the follow-up period of up to 3 years were lower in ischemic stroke compared with sepsis (adjusted hazard ratio, 1.21; 95% CI, 1.06-1.36) and severe community-acquired pneumonia (adjusted hazard ratio, 1.57; 95% CI, 1.39-1.77) and in intracerebral hemorrhage patients compared with these groups (adjusted hazard ratio, 1.14; 95% CI, 0.98-1.33 and adjusted hazard ratio, 1.49; 95% CI, 1.28-1.73). CONCLUSIONS: Stroke patients who need intensive care treatment have a high short-term mortality risk, but this alters favorably with increasing duration of survival time after ICU admission in patients with both ischemic stroke and intracerebral hemorrhage, especially compared with other populations of critically ill patients such as sepsis or severe community-acquired pneumonia patients.

Appointing nurses trained in organ donation to improve family consent rates.

BACKGROUND: One of the most important bottlenecks in the organ donation process worldwide is the high family refusal rate. AIMS AND OBJECTIVES: The main aim of this study was to examine whether family guidance by trained donation practitioners increased the family consent rate for organ donation. DESIGN: This was a prospective intervention study. METHODS: Intensive and coronary care unit nurses were trained in communication about donation (ie, trained donation practitioners) in two hospitals. The trained donation practitioners were appointed to guide the families of patients with a poor medical prognosis. When the patient became a potential donor, the trained donation practitioner was there to guide the family in making a well-considered decision about donation. We compared the family consent rate for donation with and without the guidance of a trained donation practitioner. RESULTS: The consent rate for donation with guidance by a trained donation practitioner was 58.8% (20/34), while the consent rate without guidance by a trained donation practitioner was 41.4% (41/99, P = 0.110) in those patients where the family had to decide on organ donation. CONCLUSIONS: Our data suggest that family guidance by a trained donation practitioner could benefit consent rates for organ donation. RELEVANCE TO CLINICAL PRACTICE: Trained nurses play an important role in supporting the families of patients who became potential donors to guide them through the decision-making process after organ donation request.

Interventions aimed at healthcare professionals to increase the number of organ donors: a systematic review.

BACKGROUND: The last decade, there have been many initiatives worldwide to increase the number of organ donors. However, it is not clear which initiatives are most effective. The aim of this study is to provide an overview of interventions aimed at healthcare professionals in order to increase the number of organ donors. METHODS: We systematically searched PubMed, EMBASE, CINAHL, PsycINFO, and the Cochrane Library for English language studies published until April 24, 2019. We included studies describing interventions in hospitals aimed at healthcare professionals who are involved in the identification, referral, and care of a family of potential organ donors. After the title abstract and full-text selection, two reviewers independently assessed each study's quality and extracted data. RESULTS: From the 18,854 records initially extracted from five databases, we included 22 studies in our review. Of these 22 studies, 14 showed statistically significant effects on identification rate, family consent rate, and/or donation rate. Interventions that positively influenced one or more of these outcomes were training of emergency personnel in organ donation, an electronic support system to identify and/or refer potential donors, a collaborative care pathway, donation request by a trained professional, and additional family support in the ICU by a trained nurse. The methodological quality of the studies was relatively low, mainly because of the study designs. CONCLUSIONS: Although there is paucity of data, collaborative care pathways, training of healthcare professionals and additional support for relatives of potential donors seem to be promising interventions to increase the number of organ donors. TRIAL REGISTRATION: PROSPERO, CRD42018068185.

Physician Experiences with Communicating Organ Donation with the Relatives: A Dutch Nationwide Evaluation on Factors that Influence Consent Rates.

BACKGROUND: The aim of this nationwide observational study is to identify modifiable factors in communication about organ donation that influence family consent rates. METHODS: Thirty-two intensivists specialized in organ donation systematically evaluated all consecutive organ donation requests with physicians in the Netherlands between January 2013 and June 2016, using a standardized questionnaire. RESULTS: Out of 2528 consecutive donation requests, 2095 (83%) were evaluated with physicians. The questionnaires of patients registered with consent or objection in the national donor registry were excluded from analysis. Only those questionnaires, in which the family had to make a decision about donation, were analyzed (n = 1322). Independent predictors of consent included: requesting organ donation during the conversation about futility of treatment (OR 1.8; p = 0.004), understanding of the term 'brain death' by the family (OR 2.4; p = 0.002), and consulting a donation expert prior to the donation request (OR 3.4; p < 0.001). CONCLUSIONS: Our study showed that decoupling the organ donation conversation from the conversation about futility of treatment was associated with lower family consent rates. Comprehension of the concept of brain death by the family and consultation with a transplant coordinator before the organ donation request by the physician could positively influence consent rates.

Decreased ratios of matrix metalloproteinases to tissue-type inhibitors in cerebrospinal fluid in sporadic and hereditary cerebral amyloid angiopathy.

BACKGROUND: To evaluate the potential of cerebrospinal fluid (CSF) levels of matrix metalloproteinases and tissue-type inhibitors (MMP; TIMP), and ratios of MMPs to TIMPs, to function as biomarkers for sporadic or hereditary cerebral amyloid angiopathy (CAA). METHODS: CSF concentrations of the matrix metalloproteinases MMP-2, MMP-9 and MMP-14, as well as the tissue inhibitors of metalloproteinases TIMP-1, TIMP-2 and TIMP-3, were determined using immunoassays. These assays were applied to two, independent study groups of sporadic CAA (sCAA) (n = 28/43) and control subjects (n = 40/40), as well as to groups of pre-symptomatic (n = 11) and symptomatic hereditary Dutch-CAA (D-CAA) patients (n = 12), and age-matched controls (n = 22/28, respectively). RESULTS: In the sCAA/control cohorts, inconsistent differences were found for individual MMPs and TIMPs, but MMP-2/TIMP-2 (discovery/validation: p = 0.004; p = 0.02) and MMP-14/TIMP-2 ratios (discovery/validation: p < 0.001; p = 0.04) were consistently decreased in sCAA, compared to controls. Moreover, MMP-14 was decreased in symptomatic D-CAA (p = 0.03), compared to controls. The MMP-14/TIMP-1 (p = 0.03) and MMP-14/TIMP-2 (p = 0.04) ratios were decreased in symptomatic D-CAA compared to controls and also compared to pre-symptomatic D-CAA (p = 0.004; p = 0.005, respectively). CONCLUSION: CSF MMP-2/TIMP-2 and MMP-14/TIMP-2 were consistently decreased in sCAA, compared to controls. Additionally, MMP-14/TIMP-2 levels were also decreased in symptomatic D-CAA, compared to both pre-symptomatic D-CAA and controls, and can therefore be considered a biomarker for sporadic and late-stage hereditary forms of CAA.

Oxygen-induced hypercapnia in COPD: myths and facts.

During our medical training, we learned that oxygen administration in patients with chronic obstructive pulmonary disease (COPD) induces hypercapnia through the 'hypoxic drive' mechanism and can be dangerous. This mindset frequently results in the reluctance of clinicians to administer oxygen to hypoxemic patients with COPD. However, this fear is not based on evidence in the literature. Here, we will review the impact and pathophysiology of oxygen-induced hypercapnia in patients with acute exacerbation of COPD and recommend a titrated oxygen management.

Long-term cognitive performance and its relation to anti-inflammatory therapy in a cohort of survivors of severe COVID-19.

Background and objectives: Long-term cognitive performance data in former critically ill COVID-19 patients are sparse. Current evidence suggests that cognitive decline is related to neuroinflammation, which might be attenuated by COVID-19 related anti-inflammatory therapies. The objective of this prospective cohort study was to study long term cognitive outcomes following severe COVID-19 and the relation to anti-inflammatory therapies. Methods: Prospective observational cohort of patients that survived an intensive care unit (ICU) admission due to severe COVID-19. Six months after hospital discharge, we extensively assessed both objective cognitive functioning and subjective cognitive complaints. Furthermore, patients were stratified in cohorts according to their anti-inflammatory treatment (i.e. no immunomodulatory therapy, dexamethasone, or both dexamethasone and interleukin-6 receptor antagonist tocilizumab). Results: 96 patients were included (March 2020-June 2021, median [IQR] age 61 [55-69] years). 91% received invasive mechanical ventilation, and mean ± SD severity-of-disease APACHE-II-score at admission was 15.8 ± 4.1. After 6.5 ± 1.3 months, 27% of patients scored cognitively impaired. Patients that did or did not develop cognitive impairments were similar in ICU-admission parameters, clinical course and delirium incidence. Patients with subjective cognitive complaints (20%) were more likely women (61% vs 26%), and had a shorter ICU stay (median [IQR] 8 [5-15] vs 18 [9-31], p = 0.002). Objective cognitive dysfunction did not correlate with subjective cognitive dysfunction. 27% of the participants received dexamethasone during intensive care admission, 44% received additional tocilizumab and 29% received neither. Overall occurrence and severity of cognitive dysfunction were not affected by anti-inflammatory therapy, although patients treated with both dexamethasone and tocilizumab had worse executive functioning scores (Trail Making Test interference) than patients without anti-inflammatory treatment (T-score 40.3 ± 13.5 vs 49.1 ± 9.3, p = 0.007). Discussion: A relevant proportion of critically ill COVID-19 patients shows deficits in long-term cognitive functioning. Apart from more pronounced executive dysfunction, overall, anti-inflammatory therapy appeared not to affect long-term cognitive performance. Our findings provide insight in long-term cognitive outcomes in patients who survived COVID-19, that may facilitate health-care providers counseling patients and their caregivers.

Prospective Multicenter Observational Cohort Study on Time to Death in Potential Controlled Donation After Circulatory Death Donors-Development and External Validation of Prediction Models: The DCD III Study.

BACKGROUND: Acceptance of organs from controlled donation after circulatory death (cDCD) donors depends on the time to circulatory death. Here we aimed to develop and externally validate prediction models for circulatory death within 1 or 2 h after withdrawal of life-sustaining treatment. METHODS: In a multicenter, observational, prospective cohort study, we enrolled 409 potential cDCD donors. For model development, we applied the least absolute shrinkage and selection operator (LASSO) regression and machine learning-artificial intelligence analyses. Our LASSO models were validated using a previously published cDCD cohort. Additionally, we validated 3 existing prediction models using our data set. RESULTS: For death within 1 and 2 h, the area under the curves (AUCs) of the LASSO models were 0.77 and 0.79, respectively, whereas for the artificial intelligence models, these were 0.79 and 0.81, respectively. We were able to identify 4% to 16% of the patients who would not die within these time frames with 100% accuracy. External validation showed that the discrimination of our models was good (AUCs 0.80 and 0.82, respectively), but they were not able to identify a subgroup with certain death after 1 to 2 h. Using our cohort to validate 3 previously published models showed AUCs ranging between 0.63 and 0.74. Calibration demonstrated that the models over- and underestimated the predicted probability of death. CONCLUSIONS: Our models showed a reasonable ability to predict circulatory death. External validation of our and 3 existing models illustrated that their predictive ability remained relatively stable. We accurately predicted a subset of patients who died after 1 to 2 h, preventing starting unnecessary donation preparations, which, however, need external validation in a prospective cohort.

Breakpoint mapping of 13 large parkin deletions/duplications reveals an exon 4 deletion and an exon 7 duplication as founder mutations.

Early-onset Parkinson's disease (EOPD) has been associated with recessive mutations in parkin (PARK2). About half of the mutations found in parkin are genomic rearrangements, i.e., large deletions or duplications. Although many different rearrangements have been found in parkin before, the exact breakpoints involving these rearrangements are rarely mapped. In the present study, the exact breakpoints of 13 different parkin deletions/duplications, detected in 13 patients out of a total screened sample of 116 EOPD patients using Multiple Ligation Probe Amplification (MLPA) analysis, were mapped using real time quantitative polymerase chain reaction (PCR), long-range PCR and sequence analysis. Deletion/duplication-specific PCR tests were developed as a rapid and low cost tool to confirm MLPA results and to test family members or patients with similar parkin deletions/duplications. Besides several different deletions, an exon 3 deletion, an exon 4 deletion and an exon 7 duplication were found in multiple families. Haplotype analysis in four families showed that a common haplotype of 1.2 Mb could be distinguished for the exon 7 duplication and a common haplotype of 6.3 Mb for the deletion of exon 4. These findings suggest common founder effects for distinct large rearrangements in parkin.

External Validation of the DCD-N Score and a Linear Prediction Model to Identify Potential Candidates for Organ Donation After Circulatory Death: A Nationwide Multicenter Cohort Study.

BACKGROUND: Donation after circulatory death (DCD) is a procedure in which after planned withdrawal of life-sustaining treatment (WLST), the dying process is monitored. A DCD procedure can only be continued if the potential organ donor dies shortly after WLST. This study performed an external validation of 2 existing prediction models to identify potentially DCD candidates, using one of the largest cohorts. METHODS: This multicenter retrospective study analyzed all patients eligible for DCD donation from 2010 to 2015. The first model (DCD-N score) assigned points for absence of neurological reflexes and oxygenation index. The second model, a linear prediction model (LPDCD), yielded the probability of death within 60 min. This study determined discrimination (c-statistic) and calibration (Hosmer and Lemeshow test) for both models. RESULTS: This study included 394 patients, 283 (72%) died within 60 min after WLST. The DCD-N score had a c-statistic of 0.77 (95% confidence intervals, 0.71-0.83) and the LPDCD model 0.75 (95% confidence intervals, 0.68-0.81). Calibration of the LPDCD 60-min model proved to be poor (Hosmer and Lemeshow test, P < 0.001). CONCLUSIONS: The DCD-N score and the LPDCD model showed good discrimination but poor calibration for predicting the probability of death within 60 min. Construction of a new prediction model on a large data set is needed to obtain better calibration.

Case-control study on the interplay between immunoparalysis and delirium after cardiac surgery.

BACKGROUND: Delirium occurs frequently following cardiothoracic surgery, and infectious disease is an important risk factor for delirium. Surgery and cardiopulmonary bypass induce suppression of the immune response known as immunoparalysis. We aimed to investigate whether delirious patients had more pronounced immunoparalysis following cardiothoracic surgery than patients without delirium, to explain this delirium-infection association. METHODS: A prospective matched case-control study was performed in two university hospitals. Cytokine production (tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8 and IL-10) of ex vivo lipopolysaccharide (LPS)-stimulated whole blood was analyzed in on-pump cardiothoracic surgery patients preoperatively, and at 5 timepoints up to 3 days after cardiothoracic surgery. Delirium was assessed by trained staff using two validated delirium scales and chart review. RESULTS: A total of 89 patients were screened of whom 14 delirious and 52 non-delirious patients were included. Ex vivo-stimulated production of TNF-α, IL-6, IL-8, and IL-10 was severely suppressed following cardiothoracic surgery compared to pre-surgery. Postoperative release of cytokines in non-delirious patients was attenuated by 84% [IQR: 13-93] for TNF-α, 95% [IQR: 78-98] for IL-6, and 69% [IQR: 55-81] for IL-10. The attenuation in ex vivo-stimulated production of these cytokines was not significantly different in patients with delirium compared to non-delirious patients (p > 0.10 for all cytokines). CONCLUSIONS: The post-operative attenuation of ex vivo-stimulated production of pro- and anti-inflammatory cytokines was comparable between patients that developed delirium and those who remained delirium-free after on-pump cardiothoracic surgery. This finding suggests that immunoparalysis is not more common in cardiothoracic surgery patients with delirium compared to those without.