Predictors of delirium after cardiac surgery delirium: Effect of beating-heart (off-pump) surgery

Delirium after cardiac surgery: incidence and risk factors

OBJECTIVES

Delirium after cardiac surgery is a problem with consequences for patients and healthcare. Preventive strategies from known risk factors may reduce the incidence and severity of delirium. The present aim was to explore risk factors behind delirium in older patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

Patients (≥70 years) scheduled for routine cardiac surgery were included (n = 142). The patients were assessed and monitored pre-/postoperatively, and delirium was diagnosed from repeated assessments with the Mini-Mental State Examination and the Organic Brain Syndrome Scale, using the DSM-IV-TR criteria. Variables were analysed by uni-/multivariable logistic regression, including both preoperative variables (predisposing) and those extracted during surgery and in the early postoperative period (precipitating).

RESULTS

Delirium was diagnosed in 78 patients (54.9%). Delirium was independently associated with both predisposing and precipitating factors (P-value, odds ratio, upper/lower confidence interval): age (0.036, 1.1, 1.0/1.2), diabetes (0.032, 3.5, 1.1/11.0), gastritis/ulcer problems (0.050, 4.0, 1.0/16.1), volume load during operation (0.001, 2.8, 1.5/5.1), ventilator time in ICU (0.042, 1.2, 1.0/1.4), highest temperature recorded in ICU (0.044, 2.2, 1.0/4.8) and sodium concentration in ICU (0.038, 1.2, 1.0/1.4).

CONCLUSIONS

Delirium was common among older patients undergoing cardiac surgery. Both predisposing and precipitating factors contributed to delirium. When combined, the predictive strength of the model improved. Preventive strategies may be considered, in particular among the precipitating factors. Of interest, delirium was strongly associated with an increased volume load during surgery.

Pre-existing cerebral infarcts as a risk factor for delirium after coronary artery bypass graft surgery

OBJECTIVES

Delirium is a common and critical clinical syndrome in older patients. We examined whether abnormalities in the brain that could be assessed by magnetic resonance imaging predisposed patients to develop delirium after coronary artery bypass graft surgery. We also analysed the association between delirium and cognitive dysfunction after coronary artery bypass graft surgery.

METHODS

Data were collected prospectively on 153 patients aged 60 years or older who consecutively underwent elective isolated coronary artery bypass graft surgery. All patients were assessed for prior cerebral infarctions and craniocervical artery stenosis by magnetic resonance imaging (MRI) and angiography of their brains. Atherosclerosis of the ascending aorta was examined by epiaortic ultrasound at the time of surgery. Individual cognitive status was measured using four tests in all the patients before surgery and on the seventh postoperative day. A single psychiatrist diagnosed delirium using the Diagnostic and Statistical Manual of Mental Disorders 4th edition IV criteria.

RESULTS

Postoperative delirium occurred in 16 patients (10.5%). Compared with patients who did not develop postoperative delirium, delirious patients had significantly higher rates of peripheral artery disease, preoperative decline in global cognitive function and pre-existing multiple cerebral infarctions on MRI. In addition, 9 (56%) of the delirious patients suffered postoperative cognitive dysfunction. Stepwise logistic regression analysis found significant independent predictors of postoperative delirium to be preoperative cerebral infarcts on MRI (odds ratio [OR], 2.26; 95% confidence interval [CI] 1.10-4.78), preoperative decline in global cognitive function (OR 4.54; 95% CI 1.21-16.51) and atherosclerosis of the ascending aorta (OR 2.44; 95% CI 1.03-5.62).

CONCLUSIONS

Our findings suggested that postoperative delirium was associated with pre-existing multiple cerebral infarctions on MRI, preoperative decline in global cognitive function and ascending aortic atherosclerosis in elderly patients undergoing coronary artery bypass graft surgery and increased risk of postoperative cognitive dysfunction.

Postoperative delirium in the intensive care unit predicts worse outcomes in liver transplant recipients

BACKGROUND

Delirium is common in intensive care unit patients and is associated with worse outcome.

OBJECTIVE

To identify early risk factors for delirium in patients admitted to the intensive care unit following orthotopic liver transplantation (OLT).

METHODS

An observational study of patients admitted to the intensive care unit from January 2000 to May 2010 for elective or semi-elective OLT was conducted. The primary end point was delirium in the intensive care unit. Pre- and post-transplantation and intraoperative factors potentially associated with this outcome were examined.

RESULTS

Of the 281 patients included in the study, 28 (10.03%) developed delirium in the intensive care unit at a median of two days (interquartile range one to seven days) after OLT. According to multivariate analysis, independent risk factors for delirium were intraoperative transfusion of packed red blood cells (OR 1.15 [95% CI 1.01 to 1.18]), renal replacement therapy during the pretransplantation period (OR 13.12 [95% CI 2.82 to 72.12]) and Acute Physiologic and Health Evaluation (APACHE) II score (OR per unit increase 1.10 [95% CI 1.03 to 1.29]). Using Cox proportional hazards models adjusted for baseline covariates, delirium was associated with an almost twofold risk of remaining in hospital, a fourfold increased risk of dying in hospital and an almost threefold increased rate of death by one year.

CONCLUSION

Intraoperative transfusion of packed red blood cells, pretransplantation renal replacement therapy and APACHE II score are predictors for the development of delirium in intensive care unit patients post-OLT and are associated with increased hospital lengths of stay and mortality.

Association between intraoperative blood transfusions and early postoperative delirium in older adults

OBJECTIVES

To determine whether intraoperative blood transfusion, a known trigger and amplifier of inflammation, is an independent risk factor for early postoperative delirium (POD), an acute state of confusion with fluctuating consciousness and inattention after surgery, in older adults undergoing surgery.

DESIGN

Secondary analysis using a database created for a prospective cognitive outcomes study.

SETTING

University hospital.

PARTICIPANTS

Four hundred seventy-two individuals aged 65 and older undergoing major noncardiac surgery.

MEASUREMENTS

Perioperative data were examined for association with POD on the first postoperative day. Multivariable logistic regression analysis was conducted to determine whether intraoperative blood transfusion independently predicts POD after adjusting for covariates known to be associated with onset of delirium and blood transfusions.

RESULTS

One hundred thirty-seven individuals (29%) developed delirium on the first postoperative day. The multivariable logistic regression model identified age, sex, history of central nervous system disorder, preoperative cognitive dysfunction, and pain, as well as blood transfusions, as independent risk factors for POD. Intraoperative administration of more than 1,000 mL of red blood cells (RBCs) was the strongest predictor of POD on the first postoperative day (odds ratio = 3.68; 95% confidence interval = 1.32–10.94; P < .001).

CONCLUSION

Intraoperative blood transfusion of more than 1,000 mL of RBCs increases the risk of delirium on the first postoperative day in older adults undergoing noncardiac surgery.

Incidence and causes of postoperative delirium in patients with esophageal cancer

AIM: To investigate the incidence and causes of postoperative delirium in patients with esophageal cancer.

METHODS: We conducted a retrospective cohort analysis of 124 patients who had undergone an esophagectomy at Tianjin Medical University General Hospital from January 2010 to December 2012. All quantitative data and all qualitative data were analyzed using Student's t test and Chi-square test, respectively.

RESULTS: Postoperative delirium developed in 60 (48.4%) of 124 patients. Elder age (P = 0.007), history of mental illness (P = 0.0001), longer period of time under mechanical ventilation after surgery (P = 0.0001), longer ICU stay after surgery (P = 0.0001), longer period of prohibiting drinking and eating from mouth after surgery (P = 0.0001), and occurrence of postoperative complications (P = 0.002) were significantly associated with the development of postoperative delirium.

CONCLUSION: The development of postoperative delirium in patients with esophageal cancer is a problem that should not be ignored. Causes of postoperative delirium include elder age, history of mental illness, longer periods of time under mechanical ventilation after surgery, longer postoperative ICU stays, longer periods of prohibiting drinking and eating from mouth after surgery, and occurrence of postoperative complications.

The impact of comorbidity on perioperative outcomes of hip fractures in a geriatric fracture model

BACKGROUND

Older adults who sustain hip fractures usually have multiple coexisting medical problems that may impact their treatment and outcomes. The geriatric fracture center (GFC) provides a model of care that standardizes treatment and optimizes outcomes. The purpose of this study is to determine whether GFC patients with a higher burden of comorbidity or specific comorbidities are at risk for worsened perioperative outcomes, such as increased time to surgery (TTS), postoperative complications, and longer length of hospital stay (LOS).

METHOD

A total of 1077 patients aged 60 years and older who underwent surgery for a proximal femur fracture between April 15, 2005, and September 30, 2010, were evaluated. Comorbidities measured in the Charlson Comorbidity index were abstracted through chart review. Outcomes were TTS, postoperative complications, and LOS.

RESULTS

Most patients were white, with an average age of 85. One half lived in either a nursing home or an assisted living facility. The mean Charlson score was 3.06 and the nursing home residents had a significantly higher score compared to community dwellers (3.4 vs 2.8; P < .0001). Dementia was the most common comorbidity. There was no difference in the LOS or TTS based on Charlson score. The overall complication rate was 44% with delirium being the most common postoperative complication. Peripheral vascular disease, history of solid tumor, and peptic ulcer disease predicted delirium incidence. Charlson score predicted complication risk, with an odds ratio of 1.12 for each point increase.

CONCLUSION

Frailty and comorbidity put this hip fracture population at high risk for adverse perioperative outcomes. This study shows that in the GFC model of care the comorbidity burden did not impact the TTS and LOS but did predict postoperative complication rate.

Delirium in the cardiovascular ICU: exploring modifiable risk factors

OBJECTIVE

Delirium, an acute organ dysfunction, is common among critically ill patients leading to significant morbidity and mortality; its epidemiology in a mixed cardiology and cardiac surgery ICU is not well established. We sought to determine the prevalence and risk factors for delirium among cardiac surgery ICU patients.

DESIGN

Prospective observational study.

SETTING

Twenty-seven-bed medical-surgical cardiac surgery ICU.

PATIENTS

Two hundred consecutive patients with an expected cardiac surgery ICU length of stay >24 hrs.

INTERVENTIONS

None.

MEASUREMENTS

Baseline demographic data and daily assessments for delirium using the validated and reliable Confusion Assessment Method for the ICU were recorded, and quantitative tracking of delirium risk factors were conducted. Separate analyses studied the role of admission risk factors for occurrence of delirium during the cardiac surgery ICU stay and identified daily occurring risk factors for the development of delirium on a subsequent cardiac surgery ICU day.

MAIN RESULTS

Prevalence of delirium was 26%, similar among cardiology and cardiac surgical patients. Nearly all (92%) exhibited the hypoactive subtype of delirium. Benzodiazepine use at admission was independently predictive of a three-fold increased risk of delirium (odds ratio 3.1 [1, 9.4], p = 0.04) during the cardiac surgery ICU stay. Of the daily occurring risk factors, patients who received benzodiazepines (2.6 [1.2, 5.7], p = 0.02) or had restraints or devices that precluded mobilization (2.9 [1.3, 6.5], p < 0.01) were more likely to have delirium the following day. Hemodynamic status was not associated with delirium.

CONCLUSIONS

Delirium occurred in one in four patients in the cardiac surgery ICU and was predominately hypoactive in subtype. Chemical restraints via use of benzodiazepines or the use of physical restraints/restraining devices predisposed patients to a greater risk of delirium, pointing to areas of quality improvement that would be new to the vast majority of cardiac surgery ICUs.

Treatment of delirium following cardiac surgery

Postoperative delirium is a common medical complication following cardiac surgery. This paper will outline the treatment options for delirium with a focus on prophylactic use of risperidone before cardiac surgery.

Can we identify risk factors for postoperative delirium in cardiac coronary patients? Our experience

INTRODUCTION

Delirium is a temporary mental disorder that frequently occurs among elderly hospitalized patients. Patients who undergo cardiac operations have an increased risk of postoperative delirium, which is associated with higher mortality and morbidity rates, a prolonged hospital stay, and reduced cognitive and functional recovery.

PATIENTS AND METHODS

In our prospective study, we included 370 consecutive adult patients who underwent on-pump coronary artery surgery between January 1, 2011, and July 1, 2011. We selected 21 potential risk factors and divided them into preoperative, intraoperative, and postoperative groups. Delirium was diagnosed with the Confusion Assessment Method.

RESULTS

Postoperative delirium was diagnosed in 74 patients (20%). Four predictive factors were associated with postoperative delirium: diabetes mellitus, cerebrovascular disease, peripheral vascular disease, and prolonged intubation (P < .05).

CONCLUSION

Three of the four predictive factors significantly associated with delirium are preoperative. They are relatively easy to measure and can be used to identify patients at higher risk. Fast extubation of these patients and preventive interventions can be taken to prevent negative consequences of this postoperative complication.

The impact of intra- and postoperative albumin levels as a biomarker of delirium after cardiopulmonary bypass: results of an exploratory study

In this prospective study the frequency of delirium after cardiac surgery with cardiopulmonary bypass (CPB) was determined. Furthermore, we investigated the impact of intra- and postoperative levels of albumin as a biomarker of delirium. Thirty-four patients who underwent elective CPB at the Department of Cardiac Surgery, Ludwig-Maximilians-University of Munich, Germany, were enroled in this prospective study. During the intensive care unit (ICU) stay and shortly after discharge from the ICU, delirious state was evaluated daily using the Delirium-Rating-Scale. Albumin was assayed pre-anaesthesia, immediately after induction of anaesthesia, at the beginning of the heart-lung-apparatus period, immediately before the opening and 5min after the opening of the aortic clamp, 24h and 48h postoperatively and on the day before discharge. After CPB, a clinical significant delirious state was observed in 11 patients (32.4%). The albumin level decreased during the surgical intervention and increased postoperatively with a maximum level at the time of discharge. CPB patients with delirious state showed a significantly lower albumin level 24h and 48h postoperatively than those without delirium. A low level of postoperative albumin seems to be a useful biomarker to identify patients with high risk of delirious state after CPB.

Epidemiology and risk factors for delirium across hospital settings

Delirium is one of the most common causes of acute end-organ dysfunction across hospital settings, occurring in as high as 80% of critically ill patients that require intensive care unit (ICU) care. The implications of this acute form of brain injury are profound. Across many hospital settings (emergency department, general medical ward, postoperative and ICU), a patient who experiences delirium is more likely to experience increased short- and long-term mortality, decreases in long-term cognitive function, increases in hospital length of stay and increased complications of hospital care. With the development of reliable setting-specific delirium-screening instruments, researchers have been able to highlight the predisposing and potentially modifiable risk factors that place patients at highest risk. Among the large number of risk factors discovered, administration of potent sedative medications, most notably benzodiazepines, is most consistently and strongly associated with an increased burden of delirium. Alternatively, in both the hospital and ICU, delirium can be prevented with the application of protocols that include early mobility/exercise. Future studies must work to understand the epidemiology across settings and focus upon modifiable risk factors that can be integrated into existing delirium prevention and treatment protocols.

Pharmacological risk factors for delirium after cardiac surgery: a review

PURPOSE

The objective of this review is to evaluate the literature on medications associated with delirium after cardiac surgery and potential prophylactic agents for preventing it.

SOURCE

Articles were searched in MEDLINE, Cumulative Index to Nursing and Allied Health, and EMBASE with the MeSH headings: delirium, cardiac surgical procedures, and risk factors, and the keywords: delirium, cardiac surgery, risk factors, and drugs. Principle inclusion criteria include having patient samples receiving cardiac procedures on cardiopulmonary bypass, and using DSM-IV-TR criteria or a standardized tool for the diagnosis of delirium.

PRINCIPAL FINDINGS

Fifteen studies were reviewed. Two single drugs (intraoperative fentanyl and ketamine), and two classes of drugs (preoperative antipsychotics and postoperative inotropes) were identified in the literature as being independently associated with delirium after cardiac surgery. Another seven classes of drugs (preoperative antihypertensives, anticholinergics, antidepressants, benzodiazepines, opioids, and statins, and postoperative opioids) and three single drugs (intraoperative diazepam, and postoperative dexmedetomidine and rivastigmine) have mixed findings. One drug (risperidone) has been shown to prevent delirium when taken immediately upon awakening from cardiac surgery. None of these findings was replicated in the studies reviewed.

CONCLUSION

These studies have shown that drugs taken perioperatively by cardiac surgery patients need to be considered in delirium risk management strategies. While medications with direct neurological actions are clearly important, this review has shown that specific cardiovascular drugs may also require attention. Future studies that are methodologically consistent are required to further validate these findings and improve their utility.

Factors related to postoperative delirium in patients with lower limb ischaemia: a prospective cohort study

OBJECTIVES

To preoperatively determine candidates at definitive risk of postoperative delirium (POD), we identified relevant factors in patients with arteriosclerosis obliterans who underwent bypass surgery.

DESIGN

A prospective cohort study.

PATIENTS AND METHODS

299 patients (age ≥ 60 years) who underwent bypasses in 1995-2006 were enrolled. Cognitive impairment was assessed by the Revised Hasegawa Dementia Scale, the Confusion Assessment Method was also used, and severity was graded as Grade I-III (mild to severe) based on the Delirium Rating Scale. All patients were followed for 3 years.

RESULTS

POD occurred in 88 patients (29%), with a median age of 75 (10) years (IQR). Onset was 2 (1) days postoperatively, and a duration of 2 (2) days was observed. POD was hyperactive in 89% and was Grade I, II, and III in 11%, 68%, and 21% respectively. Multiple logistic regression analysis identified the following risk factors for POD: age ≥ 72 years (<0.0001), end-stage renal failure (0.001), multiple occlusive lesions (<0.0001), cognitive impairment (0.003), and critical limb ischaemia (0.034). The 3-year survival rate was similar when comparing POD and non-POD patients (84% vs. 88%, NS).

CONCLUSIONS

This study identified 5 risk factors for POD in patients undergoing bypasses for limb ischaemia. Long-term outcomes were similar when comparing the patients who experienced POD with those who did not.

Preoperative statin therapy is not associated with a decrease in the incidence of delirium after cardiac operations

BACKGROUND

Delirium after cardiac operations is associated with significant morbidity and death. Statins have been recently suggested to exert protective cerebral effects. This study investigated whether preoperative statins were associated with decreased incidence of postoperative delirium in patients undergoing coronary artery bypass grafting.

METHODS

The study enrolled 4,659 consecutive patients (21% women; age, 67.8±9.2 years) undergoing coronary artery bypass grafting. A propensity score-based optimal-matching algorithm was used to match 1,577 patients receiving preoperative statins with a control group (1:1). Patients were screened for delirium in the intensive care unit according to the Confusion Assessment Method for the intensive care unit.

RESULTS

Delirium affected 89 patients (3%), and preoperative statin administration was not multivariably associated with a decreased incidence of delirium (odds ratio, 1.52; 95% confidence interval, 0.97 to 2.37; p=0.18) and was also unrelated to a delirium decrease in patient subgroups undergoing isolated coronary artery bypass grafting (odds ratio, 1.31; 95% confidence interval, 0.68 to 2.52; p=0.51) or combined valvular procedures (odds ratio, 1.72; 95% confidence interval, 0.96 to 3.07, p=0.08). Similar results were observed for age groups and cardiopulmonary bypass durations. Patients affected by postoperative delirium experienced a longer hospital stay (25th to 75th percentile) of 11 (7 to 18 days) vs 7 days (7 to 8 days, p<0.001) and 12% hospital mortality vs 1% (p<0.001).

CONCLUSIONS

Preoperative statins were not associated with a decreased incidence of delirium in patients undergoing coronary revascularization.

Incidence and risk factors of postoperative delirium in patients with esophageal cancer

BACKGROUND

Postoperative delirium is a common complication after major surgery and is characterized by acute confusion with fluctuating consciousness. The aim of this study was to investigate the incidence and risk factors of postoperative delirium in patients with esophageal cancer.

METHODS

We conducted a retrospective cohort analysis of 306 consecutive patients who had undergone an esophagectomy at Keio University Hospital from January 1998 to December 2009. All data were assessed by psychiatrists, and delirium was diagnosed according to criteria of the Diagnostic and Statistical Manual Disorder, fourth edition. Univariate and multivariate analyses were performed.

RESULTS

Postoperative delirium developed in 153 (50.0 %) of 306 patients. One hundred fourteen (37.3 %) of the 306 patients required psychoactive medication for symptoms associated with delirium. Univariate analyses showed that older age, male gender, additional flunitrazepam for sedation in intensive care unit (ICU) after surgery, longer periods of time under mechanical ventilation after surgery, longer ICU stays, occurrence of postoperative complications, and longer hospital stays were significantly associated with postoperative delirium. Multivariate analysis revealed that development of delirium was linked to older age, additional flunitrazepam in ICU, and occurrence of postoperative complication.

CONCLUSIONS

The development of postoperative delirium in patients with esophageal cancer is a problem that cannot be ignored. Our results suggest that the risk of developing delirium is associated with older age, use of flunitrazepam in ICU, and postoperative complications.

Ondasetron versus haloperidol for the treatment of postcardiotomy delirium: a prospective, randomized, double-blinded study

Background

To investigate the controlling efficacy of ondasetron and haloperidol in regard to the postcardiotomy delirium.

Methods

We included in this prospective, randomized, double-blinded study 80 patients who developed delirium after heart surgery with the application of heart lung-machine. The patients were divided into two, equally-sized groups, which on detection of delirium received ondasetron 8 mg iv or haloperidol 5 mg iv respectively. The statistical analysis compared the baseline and demographic characteristics of the two groups (age, gender, comorbidities, years of education, type of surgery etc.).

Results

Both ondasetron and haloperidol had very good delirium controlling effects, without statistically significant differences.

Discussion-Conclusions

Ondasetron and haloperidol are efficient agents as far as the treatment of postcardiotomy delirium is concerned. As, in addition, ondasetron bares milder side-effects, we believe this could be the agent of choice in patients developing postcardiotomy delirium in the future.

[Neurological aspects of chronic heart failure]

Chronic heart failure (CHF) is one of the leading causes of hospitalization, morbidity and mortality. Moreover, there is a high rate of neurological as well as neuropsychological comorbidities, namely ischemic stroke, structural brain alterations, cognitive impairment, sleep apnea and possible side-effects of HF medication such as delirium or (intracerebral) hemorrhage. The higher stroke risk in patients with HF increases further with age, concomitant arterial hypertension or atrial fibrillation (AF). In women the stroke risk increases with reduced ejection fraction (EF). In general stroke in HF patients is associated with a poor outcome and higher mortality, which is increased more than 2-fold. Furthermore, approximately 25-80% of all patients with CHF experience cognitive impairments such as decreased attention and concentration, memory loss, diminished psychomotor reaction time and decreased executive functions. Cognitive impairment in patients with HF has been linked to losses in gray matter, (silent) ischemic strokes, decreased cerebral perfusion and higher mortality. Moreover, sleep apnea occurs in more than half of all patients with CHF and reduced EF. However, prospective studies are needed to test whether early detection and optimal treatment of HF reduces the burden of neurological and neuropsychological sequelae.

Left anterior descending artery revascularization in low-risk patients: early outcomes after off-pump versus on-pump surgery

BACKGROUND AND AIM OF THE STUDY

This study aimed to compare the early outcomes of off-pump and on-pump myocardial revascularization in patients with stenosis in the left anterior descending artery (alone or with diagonal artery disease).

METHODS

We retrospectively reviewed the medical records of 300 patients: 150 who underwent on-pump coronary artery bypass and 150 who underwent off-pump coronary artery bypass grafting. There were no significant differences between the 2 groups with respect to medical data and operative findings. On-pump and off-pump groups were compared in terms of mortality and morbidity within 30 days of the operation.

RESULTS

Hospital mortality was 3.3% (5 patients) in the on-pump group and 2.6% (4 patients) in the off-pump group. Five patients (3.3%) in the on-pump group experienced myocardial infarction; 3 died of cardiogenic shock. Four patients (2.6%) in the off-pump group experienced myocardial infarction, and 2 of these patients died. Two patients (1.3%) in the on-pump group and 2 patients (1.3%) in the off-pump group experienced stroke; 1 patient in each group died. One patient (0.6%) in the on-pump group had mediastinitis and died of sepsis.

CONCLUSIONS

Among low-risk patients (defined according to EuroSCORE criteria) who underwent left anterior descending coronary artery bypass, the results obtained with the on-pump and off-pump methods showed no significant differences with respect to morbidity or mortality.

Postoperative delirium. Part 1: pathophysiology and risk factors

Delirium presents clinically with differing subtypes ranging from hyperactive to hypoactive. The clinical presentation is not clearly linked to specific pathophysiological mechanisms. Nevertheless, there seem to be different mechanisms that lead to delirium; for example the mechanisms leading to alcohol-withdrawal delirium are different from those responsible for postoperative delirium. In many forms of delirium, the brain's reaction to a peripheral inflammatory process is considered to be a pathophysiological key element and the aged brain seems to react more markedly to a peripheral inflammatory stimulus than a younger brain. The effects of inflammatory mediators on the brain include changes in neurotransmission and apoptosis. On a neurotransmitter level, impaired cholinergic transmission and disturbances of the intricate interactions between dopamine, serotonin and acetylcholine seem to play an important role in the development of delirium. The risk factors for delirium are categorised as predisposing or precipitating factors. In the presence of many predisposing factors, even trivial precipitating factors may trigger delirium, whereas in patients without or with only a few predisposing factors, a major precipitating insult is necessary to trigger delirium. Well documented predisposing factors are age, medical comorbidities, cognitive, functional, visual and hearing impairment and institutional residence. Important precipitating factors apart from surgery are admission to an ICU, anticholinergic drugs, alcohol or drug withdrawal, infections, iatrogenic complications, metabolic derangements and pain. Scores to predict the risk of delirium based on four or five risk factors have been validated in surgical patients.

Early post-cardiac surgery delirium risk factors

The purpose of this study was to identify the post-cardiac surgery delirium risk factors and to evaluate clinical outcomes. Data on 90 patients with postoperative delirium after cardiac surgery on cardiopulmonary bypass (CPB) were analyzed retrospectively. The patients were divided into two groups by evaluating the severity of the delirium: light and moderate delirium group (n=74) and severe delirium group (n=16). We found that the rate of early post-cardiac surgery delirium was low (4.17%). We have determined that post-cardiac surgery delirium prolonged the length of stay in the Intensive Care Unit (ICU) by (8.4 (8.6)) and the hospital stay by (23.6 (13.0)) days. The patients had higher preoperative risk scores, their age was 71.5 (8.9) years, the body mass index was 28.8 (4.4) kg/m(2), the majority were male (72.2%), and the left ventricular ejection fraction was 46.1(11.9) %. Statistical analysis by multivariable logistic regression has indicated that increasing the dose of fentanyl administered during surgery over 1.4 mg also increased the possibility of developing a severe delirium (OR=29.4, CI 4.1-210.3) and longer aortic clamping time could be independently associated with severe postoperative delirium (OR=8.0, CI 1.7-37.2). After surgery, new atrial fibrillation (AF) episodes amounted to 53.3% and, after distinguishing the delirium severity groups, AF developed in the patients belonging to the severe delirium groups statistically significantly more frequently, 81.8 vs 47.3, where p=0.01. Our data suggest that early post-cardiac surgery delirium is not a common complication, but it prolonged the length of stay at the ICU and in the hospital. The delirium risk factors, such as longer aortic clamping time, the dose of fentanyl and new atrial fibrillation episodes occurring after cardiac surgery, are associated statistically significantly with the development of severe post-cardiac surgery delirium.

Consequences of delirium after cardiac operations

BACKGROUND

Delirium is a transient mental syndrome characterized by disturbances in consciousness, cognition, and perception. The risk that delirium will develop is increased in patients who undergo cardiac operations, especially the elderly. Generally, delirium during hospital admission is independently associated with many negative consequences, such as higher mortality, increased length of hospital stay, nursing home placement after admission, and cognitive and functional decline.

METHODS

This prospective follow-up study used the Short Form 36-Item questionnaire, the Cognitive Failure Questionnaire, and a purpose-designed questionnaire to assess 300 patients who underwent elective cardiac operations at 6 months after the procedure. Postoperative delirium developed in 52 patients (17%). Mortality and readmission were also assessed.

RESULTS

Delirium after cardiac procedures is associated with increased mortality (13.5% vs 2.0% in patients without), more hospital readmissions (45.7% vs 26.5%), and reduced quality of life. It is also associated with reduced cognitive functioning, including failures in attention, memory, perception, and motor function, and with functional dysfunction such as independency in activities of daily living and mobility.

CONCLUSIONS

Postoperative delirium after cardiac operations is associated with many important consequences. These findings provide justification for intervention studies to evaluate whether delirium prevention, early recognition, or treatment strategies might improve postoperative functional and cognitive function.

Electroencephalography as a tool for assessment of brain ischemic alterations after open heart operations

Cardiac surgery is commonly associated with brain ischemia. Few studies addressed brain electric activity changes after on-pump operations. Eyes closed EEG was performed in 22 patients (mean age: 45.2 ± 11.2) before and two weeks after valve replacement. Spouses of patients were invited to participate as controls. Generalized increase of beta power most prominent in beta-1 band was an unambiguous pathological sign of postoperative cortex dysfunction, probably, manifesting due to gamma-activity slowing (“beta buzz” symptom). Generalized postoperative increase of delta-1 mean frequency along with increase of slow-wave activity in right posterior region may be hypothesized to be a consequence of intraoperative ischemia as well. At the same time, significant changes of alpha activity were observed in both patient and control groups, and, therefore, may be considered as physiological. Unexpectedly, controls showed prominent increase of electric activity in left temporal region whereas patients were deficient in left hemisphere activity in comparison with controls at postoperative followup. Further research is needed in order to determine the true neurological meaning of the EEG findings after on-pump operations.

A clinical update on delirium: from early recognition to effective management

Delirium is a neuropsychiatric syndrome characterized by altered consciousness and attention with cognitive, emotional and behavioural symptoms. It is particularly frequent in elderly people with medical or surgical conditions and is associated with adverse outcomes. Predisposing factors render the subject more vulnerable to a congregation of precipitating factors which potentially affect brain function and induce an imbalance in all the major neurotransmitter systems. Early diagnosis of delirium is crucial to improve the prognosis of patients requiring the identification of subtle and fluctuating signs. Increased awareness of clinical staff, particularly nurses, and routine screening of cognitive function with standardized instruments, can be decisive to increase detection rates of delirium. General measures to prevent delirium include the implementation of protocols to systematically identify and minimize all risk factors present in a particular clinical setting. As soon as delirium is recognized, prompt removal of precipitating factors is warranted together with environmental changes and early mobilization of patients. Low doses of haloperidol or olanzapine can be used for brief periods, for the behavioural control of delirium. All of these measures are a part of the multicomponent strategy for prevention and treatment of delirium, in which the nursing care plays a vital role.

Prophylaxis against atrial fibrillation after cardiac surgery: effective, but not routinely used--a survey of cardiothoracic units in the United kingdom

OBJECTIVE

To establish whether international recommendations on chemoprophylaxis against postoperative atrial fibrillation in cardiac surgery patients are implemented locally in cardiothoracic units in the United Kingdom; to determine which drugs are being used, how long they are given, and whether outcomes are monitored.

DESIGN

Survey of local cardiothoracic center guidelines.

SETTING

Postal and telephone survey.

PARTICIPANTS

Senior anesthesiologists and critical care staff in all 37 public cardiothoracic units in the United Kingdom.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Results were obtained from all contacted cardiothoracic units. Five units (14%) have local guidelines for chemoprophylaxis against atrial fibrillation in place. All use β-antagonists as their primary prophylactic drugs; only one unit uses amiodarone as a secondary prophylactic drug. Duration of prophylactic treatment varies, from 5 days to 6 weeks postoperatively. Thirty-two units (86%) have no local guidelines for chemoprophylaxis in place.

CONCLUSION

Chemoprophylaxis against postoperative atrial fibrillation in cardiac surgery patients remains underused, despite its effectiveness and recommendations for its routine use by several international organizations. Departmental guidelines help to ensure routine use, but this survey shows that so far only a minority of cardiothoracic units in the United Kingdom have implemented such guidelines. Awareness of the advantages of routine prophylaxis against atrial fibrillation should be improved and departmental prescribing policies encouraged.

Review articles: postoperative delirium: acute change with long-term implications

Delirium is an acute change in cognition and attention, which may include alterations in consciousness and disorganized thinking. Although delirium may affect any age group, it is most common in older patients, especially those with preexisting cognitive impairment. Patients with delirium after surgery recover more slowly than those without delirium and, as a result, have increased length of stay and hospital costs. The measured incidence of postoperative delirium varies with the type of surgery, the urgency of surgery, and the type and sensitivity of the delirium assessment. Although generally considered a short-term condition, delirium can persist for months and is associated with poor cognitive and functional outcomes beyond the immediate postoperative period. In this article, we provide a guide to assess delirium risk preoperatively and to prevent, diagnose, and treat this common and morbid condition. Care improvements such as identifying delirium risk preoperatively; training surgeons, anesthesiologists, and nurses to screen for delirium; implementing delirium prevention programs; and developing standardized delirium treatment protocols may reduce the risk of delirium and its associated morbidity.

Psychiatric manifestations in a patient after surgical management of aortic stenosis of systemic lupus erythematosus

Systemic lupus erythematosus is a chronic inflammatory autoimmune disease which damages tissue and organs. Circulation, kidney, lungs, liver, central and peripheral nervous systems, joints and skin may be damaged. It also often involves psychotic syndromes which might even be stimulated by glucocorticoid therapy. In the following article we present the case report of psychotic symptoms in a 26-year old patient after management of aortic stenosis in systemic lupus erythematosus receiving glucocorticoid therapy.

Is cortisol the key to the pathogenesis of delirium after coronary artery bypass graft surgery?

Postoperative delirium is a serious complication of cardiac surgery. However, the pathophysiology of this mental syndrome is largely unknown. Recent findings suggest an association between elevated level of cortisol and postoperative delirium. Further studies should investigate the mechanisms responsible for excessive perioperative cortisol secretion.

High serum cortisol level is associated with increased risk of delirium after coronary artery bypass graft surgery: a prospective cohort study

Introduction

The pathophysiology of postoperative delirium remains poorly understood. The purpose of this study was to examine the relationship between serum cortisol level and occurrence of early postoperative delirium in patients undergoing coronary artery bypass graft (CABG) surgery.

Methods

A total of 243 patients undergoing elective CABG surgery were enrolled. Patients were examined twice daily during the first five postoperative days and postoperative delirium was diagnosed by using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Blood samples were obtained between 7 a.m. and 8 a.m. on the first postoperative day and serum cortisol concentrations were then measured. Multivariate logistic regression analyses were performed to identify risk factors of postoperative delirium.

Results

Postoperative delirium occurred in 50.6% (123 of 243) of patients. High serum cortisol level was significantly associated with increased risk of postoperative delirium (OR 3.091, 95% CI 1.763-5.418, P < 0.001). Other independent risk factors of postoperative delirium included increasing age (OR 1.111, 95% CI 1.065-1.159, P < 0.001), history of diabetes mellitus (OR 1.905, 95% CI 1.001-3.622, P = 0.049), prolonged duration of surgery (OR 1.360, 95% CI 1.010-1.831, P = 0.043), and occurrence of complications within the first day after surgery (OR 2.485, 95% CI 1.184-5.214, P = 0.016). Patients who developed postoperative delirium had a higher incidence of postoperative complications and a prolonged duration of postoperative ICU and hospital stay.

Conclusions

Delirium was a common complication after CABG surgery. High serum cortisol level was associated with increased risk of postoperative delirium. Patients who developed delirium had outcomes worse than those who did not.

Risk factors of delirium after cardiac surgery: a systematic review

BACKGROUND

Delirium or acute confusion is a temporary mental disorder that occurs frequently among hospitalized elderly patients, but also in younger patients a delirium can develop. Patients who undergo cardiac surgery have an increased risk of developing delirium that is associated with many negative consequences. Therefore, prevention of delirium is essential. Despite the high incidence of delirium, a paucity of data on risk factors for delirium exists.

AIM

The aim of this study was to summarize the available information concerning these risk factors.

METHODS

A literature research was performed using the PubMed, Cinahl, and Cochrane Library databases and was limited to the last 10 years.

RESULTS

Our review revealed 27 risk factors; 12 predisposing and 15 precipitating factors for delirium after cardiac surgery. The most established predisposing risk factors were atrial fibrillation, cognitive impairment, depression, history of stroke, older age, and peripheral vascular disease. The most established precipitating risk factor was a red blood cell transfusion. An abnormal albumin level was reported as the most established precipitating risk factor among blood values tested. A low cardiac output and the use of an Intra Aortic Balloon Pump or inotropic medication seem to be the most relevant risk factors associated with a postoperative delirium.

CONCLUSION

A multifactorial risk model should be applied to identify patients at an increased risk of developing delirium following elective cardiac surgery. In these patients, if possible, preventative interventions can be taken and early recognition of delirium can be realized. This could potentially decrease the incidence of delirium and negative consequences caused by a postoperative delirium.

Incidence and predictors of delirium after cardiac surgery: Results from The IPDACS Study

OBJECTIVE

Delirium after cardiac surgery is a serious complication that results in higher morbidity and mortality rates, and prolongs hospitalisation. However, the knowledge base regarding the issue of postoperative delirium is still limited. Therefore, in the current study, we evaluated the incidence and independent perioperative risk factors of delirium after cardiac surgery.

METHODS

The IPDACS Study recruited 563 consecutive patients undergoing cardiac surgery with cardiopulmonary bypass. The subjects were preoperatively examined by psychiatrists using the Mini-Mental State Examination and the Mini International Neuropsychiatric Interview to assess psychiatric comorbidity. Additionally, other variables connected to the patients' medical condition and surgical and anaesthetic procedures were evaluated. A diagnosis of delirium following surgical intervention was based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria.

RESULTS

The incidence of postoperative delirium according to DSM-IV criteria was 16.3% (95% confidence interval: 13.5-19.6). Multivariate stepwise logistic regression analysis revealed that advanced age, preoperative cognitive impairment, an ongoing episode of major depression, anaemia, atrial fibrillation, prolonged intubation and postoperative hypoxia were independently associated with delirium after cardiac surgery.

CONCLUSION

According to the current analysis, the aforementioned conditions independently predispose to delirium following cardiac surgery. Since some of these factors can be successfully treated and eliminated preoperatively and postoperatively, this study should be helpful in reducing the risk of delirium and in improving the medical care of patients undergoing cardiac surgery (Clinical Trials Identifier: NCT00784576).

Predictive Model for Postoperative Delirium in Cardiac Surgical Patients

Delirium is a common complication following cardiac surgery, and the predictors of delirium remain unclear. The authors performed a prospective observational analysis to develop a predictive model for postoperative delirium using demographic and procedural parameters. A total of 112 adult postoperative cardiac surgical patients were evaluated twice daily for delirium using the Richmond Agitation-Sedation Scale (RASS) and Confusion Assessment Model for the ICU (CAM-ICU). The incidence of delirium was 34% (n = 38). Increased age (odds ratio [OR] = 2.5; 95% confidence interval [CI] = 1.6-3.9; P < .0001, per 10 years) and increased duration of surgery (OR = 1.3; 95% CI = 1.1-1.5; P = .0002, per 30 minutes) were independently associated with postoperative delirium. Gender, BMI, diabetes mellitus, preoperative ejection fraction, surgery type, length of cardiopulmonary bypass, intraoperative blood component administration, Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, and Charlson Comorbidity Index, were not independently associated with postoperative delirium.

Size of left cardiac chambers correlates with cerebral microembolic load in open heart operations

Background. Microemboli are a widely recognized etiological factor of cerebral complications in cardiac surgery patients. The present study was aimed to determine if size of left cardiac chambers relates to cerebral microembolic load in open heart operations. Methods. Thirty patients participated in the study. Echocardiography was performed in 2-3 days before surgery. A transcranial Doppler system was used for registering intraoperative microemboli. Results. Preoperative left atrium and left ventricular end-systolic and end-diastolic sizes significantly correlated with intraoperative microembolic load (rs = 0.48, 0.57 and 0.53, Ps < .01, resp.). The associations between left ventricular diameters and number of cerebral microemboli remained significant when cardiopulmonary bypass time was included as a covariate into the analysis. Conclusions. The present results demonstrate that increased size of left heart chambers is an influential risk factor for elevated cerebral microembolic load during open heart operations. Mini-invasive surgery and carbon dioxide insufflation into wound cavity may be considered as neuroprotective approaches in patients with high risk of cerebral microembolism.

The neuroinflammatory hypothesis of delirium

Delirium is a neuropsychiatric syndrome characterized by a sudden and global impairment in consciousness, attention and cognition. It is particularly frequent in elderly subjects with medical or surgical conditions and is associated with short- and long-term adverse outcomes. The pathophysiology of delirium remains poorly understood as it involves complex multi-factorial dynamic interactions between a diversity of risk factors. Several conditions associated with delirium are characterized by activation of the inflammatory cascade with acute release of inflammatory mediators into the bloodstream. There is compelling evidence that acute peripheral inflammatory stimulation induces activation of brain parenchymal cells, expression of proinflammatory cytokines and inflammatory mediators in the central nervous system. These neuroinflammatory changes induce neuronal and synaptic dysfunction and subsequent neurobehavioural and cognitive symptoms. Furthermore, ageing and neurodegenerative disorders exaggerate microglial responses following stimulation by systemic immune stimuli such as peripheral inflammation and/or infection. In this review we explore the neuroinflammatory hypothesis of delirium based on recent evidence derived from animal and human studies.

Delirium following acute myocardial infarction: incidence, clinical profiles, and predictors

PURPOSE

To examine the incidence, clinical profile, and predictors of delirium following acute myocardial infarction (MI).

DESIGN AND METHODS

The study sample included 212 consecutive patients with acute MI who were admitted to the coronary intensive care unit of a university hospital.

FINDINGS

Delirium was found to occur in 5.7% of the patients. The predictors of delirium were advanced age, higher level of serum potassium at admission, and experience of cardiac arrest during MI.

PRACTICE IMPLICATIONS

Delirium is reasonably prevalent in patients with acute MI. We propose that patients with the risk factors that have been delineated in this study should be evaluated carefully.

Off-pump coronary artery revascularization in octogenarians: is it better?

PURPOSE OF REVIEW

Octogenarians are the fastest growing stratum of the population and have the highest prevalence of coronary artery disease. In the past, physicians have been reluctant to provide these patients with optimal care. Seniors are frequently excluded from large randomized trials and generally not included in published guidelines. The purpose of this review is to revisit the demography and epidemiology of coronary artery disease in this population as well as therapeutic strategies used.

RECENT FINDINGS

Recent publications have shown significant advancement in medical and invasive treatment of coronary artery disease in elderly, with special focus on the potential benefit of off-pump coronary artery bypass (OPCAB) surgery.

SUMMARY

Although OPCAB surgery has gained popularity over the past 15 years, its benefit regarding operative mortality and major complications has not been clearly defined in the general population. There is a body of literature supporting its benefit in the elderly population. OPCAB surgery has the potential of decreasing operative mortality and major postoperative complications such as stroke, delirium, atrial fibrillation, and decline in neurocognitive functions in these patients. Off-pump surgery is technically more demanding and has been blamed for providing less complete revascularization and lower graft patency rate, especially in less experienced hands. However, with the upcoming demographic explosion of senior citizens in western societies, OPCAB surgery has definitely to be a part of the armamentarium of modern cardiac surgeons.

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

OBJECTIVES

Postoperative delirium after cardiac surgery is associated with increased morbidity and mortality as well as prolonged stay in both the intensive care unit and the hospital. The authors sought to identify modifiable risk factors associated with the development of postoperative delirium in elderly patients after elective cardiac surgery in order to be able to design follow-up studies aimed at the prevention of delirium by optimizing perioperative management.

DESIGN

A post hoc analysis of data from patients enrolled in a randomized controlled trial was performed.

SETTING

A single university hospital.

PARTICIPANTS

One hundred thirteen patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

None. MEASUREMENTS AND MAINS RESULTS: Screening for delirium was performed using the Confusion Assessment Method (CAM) on the first 6 postoperative days. A multivariable logistic regression model was developed to identify significant risk factors and to control for confounders. Delirium developed in 35 of 113 patients (30%). The multivariable model showed the maximum value of C-reactive protein measured postoperatively, the dose of fentanyl per kilogram of body weight administered intraoperatively, and the duration of mechanical ventilation to be independently associated with delirium.

CONCLUSIONS

In this post hoc analysis, larger doses of fentanyl administered intraoperatively and longer duration of mechanical ventilation were associated with postoperative delirium in the elderly after cardiac surgery. Prospective randomized trials should be performed to test the hypotheses that a reduced dose of fentanyl administered intraoperatively, the use of a different opioid, or weaning protocols aimed at early extubation prevent delirium in these patients.