Evaluation of the prevalence and risk factors of delirium in cardiac surgery ICU

Identification of early delirium and its outcomes after cardiopulmonary bypass among adult patients with cardiovascular disease: a prospective observational study

Purpose

To identify the incidence and outcomes of postoperative delirium after cardiopulmonary bypass machine in adult cardiac surgery patients.

Method

A prospective observational study was conducted in a single-center institution in the Republic of China. This study included 273 patients who underwent cardiac surgical procedures requiring cardiopulmonary bypass machine utilization.

Results

This study used the Confusion Assessment Method to screen for delirium. Univariate analysis identified advanced age, emergency surgery and prolonged aortic cross-clamping time as significant predisposing factors for delirium, which occurred in 19.8% (n = 54) of cases and typically developed in average of 4.8 ± 3.28 days after the surgery. The analysis also identified that delirium was associated with increased complications and external referrals. A total of 142 patients (52.1%) were discharged to their homes, wherein the discharge rate in the delirium group was notably lower, with only 35.2% (n = 19) of patients, than in the delirium-free group with 56.2% (n = 123) of patients.

Conclusion

Considering the increased probability of delirium-related complications following cardiac surgery, it is important to develop effective preventive strategies for patients with perioperative risk factors, such as advanced age, emergency surgery and prolonged cross-clamp time, by implementing practical measures to minimize the risk of delirium.

Infarct-related structural disconnection and delirium in surgical aortic valve replacement patients

OBJECTIVE

Although acute brain infarcts are common after surgical aortic valve replacement (SAVR), they are often unassociated with clinical stroke symptoms. The relationship between clinically "silent" infarcts and in-hospital delirium remains uncertain; obscured, in part, by how infarcts have been traditionally summarized as global metrics, independent of location or structural consequence. We sought to determine if infarct location and related structural connectivity changes were associated with postoperative delirium after SAVR.

METHODS

A secondary analysis of a randomized multicenter SAVR trial of embolic protection devices (NCT02389894) was conducted, excluding participants with clinical stroke or incomplete neuroimaging (N = 298; 39% female, 7% non-White, 74 ± 7 years). Delirium during in-hospital recovery was serially screened using the Confusion Assessment Method. Parcellation and tractography atlas-based neuroimaging methods were used to determine infarct locations and cortical connectivity effects. Mixed-effect, zero-inflated gaussian modeling analyses, accounting for brain region-specific infarct characteristics, were conducted to examine for differences within and between groups by delirium status and perioperative neuroprotection device strategy.

RESULTS

23.5% participants experienced postoperative delirium. Delirium was associated with significantly increased lesion volumes in the right cerebellum and temporal lobe white matter, while diffusion weighted imaging infarct-related structural disconnection (DWI-ISD) was observed in frontal and temporal lobe regions (p-FDR < 0.05). Fewer brain regions demonstrated DWI-ISD loss in the suction-based neuroprotection device group, relative to filtration-based device or standard aortic cannula.

INTERPRETATION

Structural disconnection from acute infarcts was greater in patients who experienced postoperative delirium, suggesting that the impact from covert perioperative infarcts may not be as clinically "silent" as commonly assumed.

Standardized pharmacological management of delirium after on-pump cardiac surgery reduces ICU stay and ventilation in a retrospective pre-post study

Cardiac surgery patients not only undergo a highly invasive procedure but are at risk for a diversity of postoperative complications. Up to 53% of these patients suffer from postoperative delirium (POD). This severe and common adverse event increases mortality and prolonged mechanical ventilation and extends the intensive care unit stay. The objective of this study was to test the hypothesis that standardized pharmacological management of delirium (SPMD) may reduce the length of stay in the intensive care unit (ICU), duration of postoperative mechanical ventilation, and the incidence of postoperative complications such as pneumonia or bloodstream infections in on-pump cardiac surgery ICU patients. In this retrospective, single-center observational cohort study, 247 patients were examined between May 2018 to June 2020, who underwent on-pump cardiac surgery, suffered from POD, and received pharmacological POD treatment. 125 were treated before and 122 after SPMD implementation in the ICU. The primary endpoint was a composite outcome, including the length of ICU stay, postoperative mechanical ventilation time, and ICU survival rate. The secondary endpoints were complications including postoperative pneumonia and bloodstream infections. Although the ICU survival rate was not significantly different between both groups, the length of ICU stay (control group: 23 ± 27 days; SPMD group: 16 ± 16 days; p = 0.024) and the duration of mechanical ventilation were significantly reduced in the SPMD-cohort (control group: 230 ± 395 h; SPMD group: 128 ± 268 h; p = 0.022). Concordantly, the pneumonic risk was reduced after SPMD introduction (control group: 44.0%; SPMD group: 27.9%; p = 0.012) as well as the incidence for bloodstream infections (control group: 19.2%; SPMD group: 6.6%; p = 0.004). Standardized pharmacological management of postoperative delirium in on-pump cardiac surgery ICU patients reduced the length of ICU stay and duration of mechanical ventilation significantly, leading to a decrease in pneumonic complications and bloodstream infections.

Thyroid hormone, cortisol, interleukin-2, and procalcitonin regulate postoperative delirium in acute type A aortic dissection patients

BACKGROUND

We assessed the relationships between levels of preoperative thyroid hormone (TH), cortisol, interleukin-2 (IL-2), and procalcitonin (PCT) and postoperative delirium (POD) in acute type A aortic dissection (ATAAD) patients receiving modified triple-branched stent-graft (MTBSG) implant surgeries.

METHODS

ATAAD patients received MTBSG implant surgeries in our hospital between February 2019 and December 2020 were recruited. We separated them into a POD and non-POD cohort and employed univariable and multivariable regression analysis to establish independent correlations between preoperative THs, cortisol, IL-2, and PCT and POD. In addition, we conducted stratification analyses to examine the link between pre-surgical THs and POD in normal TSH and lower TSH subgroups.

RESULTS

POD occurred in 78 of 224 patients (34.8%). POD patients exhibited markedly reduced preoperative free triiodothyronine (FT3) (P = 0.008) and free thyroxine (FT4) (P = 0.023) levels, while remarkably enhanced preoperative cortisol (P < 0.001), IL-2 (P < 0.001), and PCT (P < 0.001) levels. Based on multivariate regression analysis, reduced preoperative FT3 (P = 0.032), as well as augmented preoperative IL-2 (P = 0.001), cortisol (P < 0.001), and PCT (P = 0.016) were strong stand-alone risk factors for POD. Moreover, subgroup analysis found the association between FT3 (P = 0.029), FT4 (P = 0.042) and POD was both significant in patients with normal TSH levels.

CONCLUSIONS

Reduced preoperative FT3 and elevated preoperative cortisol, IL-2, and PCT were strong indicators of POD in ATAAD patients. Hence, we recommend that the thyroid function, cortisol, PCT, and IL-2 should be evaluated prior to surgery in ATAAD patients.

Outcomes of postoperative delirium in patients undergoing cardiac surgery: A systematic review and meta-analysis

Background

Postoperative delirium (POD) is an acute brain dysfunction that is frequently observed in patients undergoing cardiac surgery. Increasing evidence indicates POD is related to higher mortality among cardiac surgical patients, but the results remain controversial. Moreover, a quantitative evaluation of the influence of POD on hospital days, intensive care unit (ICU) time, and mechanical ventilation (MV) time has not been performed.

Objective

This study aimed to evaluate the correlation between POD and outcomes in patients undergoing cardiac surgery by a systematic review and meta-analysis.

Materials and methods

A total of 7 electronic databases (Cochrane Library, PubMed, EMBASE, CINAHL Complete, MEDLINE, Wan-fang database, and China National Knowledge Infrastructure) were searched from January 1980 to July 20, 2021, with language restrictions to English and Chinese, to estimate the impact of the POD on outcome in patients who underwent cardiac surgery. The meta-analysis was registered with PROSPERO (Registration: CRD42021228767).

Results

Forty-two eligible studies with 19785 patients were identified. 3368 (17.0%) patients were in the delirium group and 16417 (83%) were in the non-delirium group. The meta-analysis showed that compared to patients without POD, patients with POD had 2.77-fold higher mortality (OR = 2.77, 95% CI 1.86-4.11, P < 0.001), 5.70-fold higher MV (>24h) rate (OR = 5.70, 95% CI 2.93-11.09, P < 0.001); and longer MV time (SMD = 0.83, 95% CI 0.57-1.09, P < 0.001), ICU time (SMD = 0.91, 95% CI 0.60-1.22, P < 0.001), hospital days (SMD = 0.62, 95% CI 0.48-0.76, P < 0.001).

Conclusion

The synthesized evidence suggests that POD is causally related to the increased risk of mortality, prolonged length of ICU and hospital stay, and a longer duration of MV time. Future research should focus on the interventions for POD, to reduce the incidence.

Systematic review registration

[www.crd.york.ac.uk/PROSPERO], identifier [CRD42021228767].

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

Background

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

Methods

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

Results

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

Conclusions

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

Trial registration

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

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.

Perioperative predictors of delirium and incidence factors in adult patients post cardiac surgery

Background

Delirium is a quite common complication in adult patients post-cardiac surgery. The purpose of our study was to identify perioperative characteristics and also focus on incidence factors that could predict delirium in the cardiac surgery intensive care unit (CICU) postoperatively.

Methods

We conducted a prospective study of 179 consecutive patients, who underwent open-heart surgical operation and were admitted to the CICU of a general tertiary hospital in Athens, Greece. The patients were screened for delirium by using the diagnostic tools of Rich-mond Agitation Sedation Scale (RASS score) and the Confusion Assessment Method - ICU (CAM-ICU). The delirium assessment was carried out on the 1st and the 2nd postoperative day, and was conducted twice every nursing shift. A short questionnaire on sociodemographics and clinical patient characteristics was used for data collection purposes.

Results

A total of 179 patients who underwent open-heart surgical operation with cardiopulmonary bypass (CPB) were enrolled in our study. The 2-day incidence of postoperative delirium in ICU was 11.2% (n=20/179). The main independent predictors of delirium on the 2nd postoperative day were neutrophil-to-lymphocyte ratio (p=0.001) and urea levels (p=0.016). Additionally, increased perioperative creatinine (p=0.006) and sodium (p=0.039) levels were significantly associated with delirium occurrence. Furthermore, elevated EuroSCORE (p=0.001), extended length of stay (LOS) in ICU (p<0.001), and extended LOS with endotracheal tube (p=0.001) were also statistically significant indicators.

Conclusion

Patients with extended LOS with endotracheal tube and prolonged stay in ICU in accordance with peaked urea, neutrophil-to-lymphocyte ratio, creatinine, and sodium levels seem to have a significantly greater probability of developing delirium in the ICU. Further research is needed in the field of postoperative cardiac patients in order to determine the causality and etiology of certain risk factors for delirium.

Hypertension, mitral valve disease, atrial fibrillation and low education level predict delirium and worst outcome after cardiac surgery in older adults

Background

Delirium is a common complication after cardiac surgery in older adult patients. However, risk factors and the influence of delirium on patient outcomes are not well established. We aimed to determine the incidence, predisposing and triggering factors of delirium following cardiac surgery.

Methods

One hundred seventy-three consecutive patients aged ≥60 years were studied. Patients’ characteristics and two cognitive function assessment tests were recorded preoperatively. Perioperative variables were blood transfusion, orotracheal intubation time (OIT), renal dysfunction, and hypoxemia. Delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit. The composite outcome consisted of death, infection, and perioperative myocardial infarction until hospital discharge or 30 days after surgery, and for up to 18 months.

Results

One hundred six patients (61.27%) were men and the age was 69.5 ± 5.8 years. EuroSCORE II index was 4.06 ± 3.86. Hypertension was present in 75.14%, diabetes in 39.88%, and 30.06% were illiterate. Delirium occurred in 59 patients (34.1%). Education level (OR 0.81, 0.71–0.92), hypertension (OR 2.73, 1.16–6.40), and mitral valve disease (OR 2.93, 1.32–6.50) were independent predisposing factors for delirium, and atrial fibrillation after surgery (OR 2.49, 1.20–5.20) represented the potential triggering factor. Delirium (OR 2.35, 1.20–4.58) and OIT ≥ 900 min (OR 2.50; 1.30–4.80) were independently associated with the composite outcome.

Conclusions

In older adult patients submitted to cardiac surgery, delirium is a frequent complication that is associated with worst outcome. Independent risk factors for delirium included education level, hypertension, mitral valve disease, and atrial fibrillation after cardiac surgery.

Dexmedetomidine vs morphine and midazolam in the prevention and treatment of delirium after adult cardiac surgery; a randomized, double-blinded clinical trial

Background:

The aim of this clinical study was to evaluate the efficacy of neurobehavioral, hemodynamics and sedative characteristics of dexmedetomidine compared with morphine and midazolam-based regimen after cardiac surgery at equivalent levels of sedation and analgesia in improving clinically relevant outcomes such as delirium.

Methods:

Sixty patients were randomly allocated into one of two equal groups: group A = 30 patients received dexmedetomidine infusion (0.4–0.7 μg/kg/h) and Group B = 30 patients received morphine in a dose of 10–50 μg/kg/h as an analgesic with midazolam in a dose of 0.05 mg/kg up to 0.2 mg/kg as a sedative repeated as needed. Titration of the study medication infusions was conducted to maintain light sedation (Richmond agitation-sedation scale) (−2 to +1). Primary outcome was the prevalence of delirium measured daily through confusion assessment method for intensive care.

Results:

Group A was associated with shorter length of mechanical ventilation, significant shorter duration of intensive care unit (ICU) stay (P = 0.038), and lower risk of delirium following cardiac surgery compared to Group B. Group A showed statistically significant decrease in heart rate values 4 h after ICU admission (P = 0.015) without significant bradycardia. Group A had lower fentanyl consumption following cardiac surgery compared to Group B.

Conclusion:

Dexmedetomidine significantly reduced the length of stay in ICU in adult cardiac surgery with no significant reduction in the incidence of postoperative delirium compared to morphine and midazolam.

Exploratory and Confirmatory Factor Analyses of Delirium Symptoms in a Sample of Nursing Home Residents

OBJECTIVE

This study examined the latent constructs of delirium symptoms among nursing home (NH) residents in the United States.

METHOD

Cross-sectional NH assessment data (Minimum Data Set 2.0) from the 2009 Medicare Current Beneficiary Survey were used. Data from two independent, randomly selected subsamples of residents ≥65 years were analyzed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA).

RESULTS

There were 367 and 366 individuals in the EFA and CFA, respectively. Assessment of multiple model fit statistics in CFA indicated that the two-factor structure provided better fit for the data than a one-factor solution. The two factors represented cognitive and behavioral latent constructs as suggested by the related literature. A correlation of .72 between these constructs suggested moderate discriminant validity.

CONCLUSION

This finding emphasizes the importance of health care providers to be attentive to both cognitive and behavioral symptoms when diagnosing, treating, and managing delirium.

The major risk factors for delirium in a clinical setting

OBJECTIVE

We aimed to determine the major risk factors for the development of delirium in patients at a single general hospital by comparison with a control group.

SUBJECTS AND METHODS

We reviewed the medical records of 260 delirium patients and 77 control patients. We investigated age, sex, and risk factors for delirium in the total delirium group (n=260), the delirium medical subgroup (n=142), and the delirium surgical subgroup (n=118). Logistic regression analysis adjusting for age and sex was performed to identify the odds ratio.

RESULTS

The mean age and the percentage of males were significantly higher in the delirium group compared with the control group (68.9 vs 54.3 years and 70% vs 41.6%, respectively). Risk factors for the delirium group were lower plasma albumin, hypertension, mechanical ventilation, and antipsychotic drug use. Plasma sodium level and hypertension were important risk factors for the delirium medical subgroup. Stroke history, hypertension, ICU care, and medication were important risk factors for the delirium surgical subgroup.

CONCLUSION

Lower plasma albumin, hypertension, mechanical ventilation, and antipsychotic drug use are important risk factors for delirium.