Apolipoprotein E e4 Allele Increases the Risk of Early Postoperative Delirium in Older Patients Undergoing Noncardiac Surgery

Background: Whether patients who subsequently develop early postoperative delirium have a genetic predisposition that renders them at risk for postoperative delirium has not been determined.

Methods: The authors conducted a nested cohort study to include patients aged >= 65 yr who were scheduled to undergo major noncardiac surgery requiring anesthesia. A structured interview was conducted preoperatively and for the first 2 days postoperatively to determine the presence of delirium, defined using the Confusion Assessment Method. Blood was drawn for measurement of the apolipoprotein genotypes. Bivariate tests of association were conducted between delirium and apolipoprotein genotypes and other potentially important risk factors. Variables that had significant bivariate association with postoperative delirium were entered in a forward multivariable logistic regression model.

Results: Of the 190 patients studied, 15.3% developed delirium on both days 1 and 2 after surgery. Forty-six patients (24.2%) had at least one copy of the apolipoprotein e4 allele. The presence of one copy of the e4 allele was associated with an increased risk of early postoperative delirium (28.3% vs. 11.1%; P = 0.005). Even after adjusting for covariates, patients with one copy of the e4 allele were still more likely to have an increased risk of early postoperative delirium (odds ratio, 3.64; 95% confidence interval, 1.51-8.77) compared with those without the e4 allele.     

Apolipoprotein E e4 allele does not increase the risk of early postoperative delirium after major surgery

Background

A relationship between patients with a genetic predisposition to and those who develop postoperative delirium has not been yet determined. The aim of this study was to determine whether there is an association between apolipoprotein E epsilon 4 allele (APOE4) and delirium after major surgery.

Methods

Of 230 intensive care patients admitted to the post anesthesia care unit (PACU) over a period of 3?months, 173 were enrolled in the study. Patients?? demographics and intra- and postoperative data were collected. Patients were followed for the development of delirium using the Intensive Care Delirium Screening Checklist, and DNA was obtained at PACU admission to determine apolipoprotein E genotype.

Results

Fifteen percent of patients developed delirium after surgery. Twenty-four patients had one copy of APOE4. The presence of APOE4 was not associated with an increased risk of early postoperative delirium (4% vs. 17%; P?=?0.088). The presence of APOE4 was not associated with differences in any studied variables. Multivariate analysis identified age [odds ratio (OR) 9.3, 95% confidence interval (CI) 2.0?C43.0, P?=?0.004 for age ??65?years), congestive heart disease (OR 6.2, 95% CI 2.0?C19.3, P?=?0.002), and emergency surgery (OR 59.7, 95% CI 6.7?C530.5, P?<?0.001) as independent predictors for development of delirium. The Simplified Acute Physiology Score II (SAPS II) and The Acute Physiology and Chronic Health Evaluation II (APACHE II) were significantly higher in patients with delirium (P?<?0.001 and 0.008, respectively). Hospital mortality rates of these patients was higher and they had a longer median PACU stay.

Conclusions

Apolipoprotein e4 carrier status was not associated with an increased risk for early postoperative delirium. Age, congestive heart failure, and emergency surgery were independent risk factors for the development of delirium after major surgery.     

Apolipoprotein E genotype and cognitive dysfunction after noncardiac surgery

BACKGROUND: Apolipoprotein E is important in recovery after neuronal damage. The epsilon4 allele of the apolipoprotein E gene has been shown as a risk factor for Alzheimer disease, poor outcome after cerebral injury, and accelerated cognitive decline with normal aging. The authors hypothesized that patients with the epsilon4 allele would have an increased risk of postoperative cognitive dysfunction (POCD) after noncardiac surgery. METHODS: In a multicenter study, a total of 976 patients aged 40 yr and older undergoing noncardiac surgery were tested preoperatively and 1 week and 3 months after surgery with a neuropsychological test battery comprising seven subtests. POCD was defined as a decline in test performance of more than 2 SD from the expected. Apolipoprotein E genotypes were determined by blood sample analysis at a central laboratory. Multivariate logistic regression analysis with POCD as the dependent variable assessed presence of the epsilon4 allele (yes/no) and other possible risk factors. RESULTS: The epsilon4 allele was found in 272 patients. One week after surgery, the incidence of POCD was 11.7% in patients with the epsilon4 allele and 9.9% in patients without the epsilon4 allele (P = 0.41). Three months later, POCD was found in 10.3% of patients with the epsilon4 allele and in 8.4% of patients without the epsilon4 allele (P = 0.40). Multivariate logistic regression analysis did not identify the epsilon4 allele as a risk factor at 1 week (P = 0.33) or 3 months (P = 0.57). CONCLUSIONS: The authors were unable to show a significant association between apolipoprotein E genotype and POCD, but statistical power was limited because of a lower incidence of POCD than expected.     

Apolipoprotein E Genotype and Cognitive Dysfunction after Noncardiac Surgery

Background: Apolipoprotein E is important in recovery after neuronal damage. The [epsilon]4 allele of the apolipoprotein E gene has been shown as a risk factor for Alzheimer disease, poor outcome after cerebral injury, and accelerated cognitive decline with normal aging. The authors hypothesized that patients with the [epsilon]4 allele would have an increased risk of postoperative cognitive dysfunction (POCD) after noncardiac surgery.

Methods: In a multicenter study, a total of 976 patients aged 40 yr and older undergoing noncardiac surgery were tested preoperatively and 1 week and 3 months after surgery with a neuropsychological test battery comprising seven subtests. POCD was defined as a decline in test performance of more than 2 SD from the expected. Apolipoprotein E genotypes were determined by blood sample analysis at a central laboratory. Multivariate logistic regression analysis with POCD as the dependent variable assessed presence of the [epsilon]4 allele (yes/no) and other possible risk factors.

Results: The [epsilon]4 allele was found in 272 patients. One week after surgery, the incidence of POCD was 11.7% in patients with the [epsilon]4 allele and 9.9% in patients without the [epsilon]4 allele (P = 0.41). Three months later, POCD was found in 10.3% of patients with the [epsilon]4 allele and in 8.4% of patients without the [epsilon]4 allele (P = 0.40). Multivariate logistic regression analysis did not identify the [epsilon]4 allele as a risk factor at 1 week (P = 0.33) or 3 months (P = 0.57).     

Postoperative cognitive disorders in the elderly

TWO DISTINCT CATEGORIES: Postoperative cognitive disorders include delirium and long-term cognitive dysfunction. DELERIUM: Delirium is an acute state occurring early during the postoperative period. It may be considered as an acute cerebral insufficiency which may be consecutive both to the negative effects of aging and chronic illness on cognitive function, and to the cerebral impact of operative stress. In addition, precipitating postoperative medical factors may facilitate cerebral failure. Only a few studies have been devoted to prevention programs aimed at reducing the risk of postoperative delirium. Nevertheless, we can hypothesize that a preoperative gerontology assessment would be effective in determining risk factors of delirium in old patients and thus enable proposing individual postoperative management. LONG-TERM COGNITIVE DYSFUNCTION: The definition of this clinical picture is less precise than delirium. Long-term cognitive dysfunction corresponds to a loss of cognitive performance in the weeks and months after anesthesia. The IPOCD1 study conducted in a large cohort of elderly patients has shown that postoperative cognitive dysfunction was present in 25.8% of patients 1 week after surgery and in 9.9% 3 months after surgery. One to two years after surgery, cognitive dysfunction was observed in 10.4% of patients compared with 10.6% in a control population of non-operated patients. We would suggest that in many cases, postoperative cognitive dysfunction may result from preoperative dementia unmasked by surgery.     

Preliminary report on the association of apolipoprotein E polymorphisms, with postoperative peak serum creatinine concentrations in cardiac surgical patients

BACKGROUND: Renal dysfunction after cardiac surgery occurs in up to 8% of patients and is associated with major increases in morbidity, mortality, and cost. Genetic polymorphisms have been implicated as a factor in the progression of chronic renal disease, but a genetic basis for the development of acute renal impairment has not been investigated. The authors therefore tested the hypothesis that apolipoprotein E alleles are associated with different postoperative changes in serum creatinine after cardiac surgery. METHODS: The authors performed a prospective observational study with use of data from 564 coronary bypass surgical patients who were enrolled in an ongoing investigation of apolipoprotein E genotypes and organ dysfunction at a university hospital between 1989-1999. Renal function was assessed among apolipoprotein E genotype groups by comparisons of preoperative (CrPre), peak in-hospital postoperative (CrMax) and perioperative change (DCr) in serum creatinine values. RESULTS: The epsilon4 allele grouping (E2 = 2/2,2/3,2/4; E3 = 3/3; E4 = 3/4,4/4) was associated with a smaller increase in postoperative serum creatinine (perioperative change: E4, +0.17; E3, +0.26; E4, +0.27 mg/dl) and a lower peak postoperative creatinine than the epsilon2 and epsilon3 in univariate and multivariate analysis (peak in-hospital postoperative serum creatinine multivariate P = 0.015 vs. epsilon3, P = 0.038 vs. epsilon2). There was no difference in baseline creatinine among allele groups. CONCLUSIONS: Inheritance of the apolipoprotein epsilon4 allele is associated with reduced postoperative increase in serum creatinine after cardiac surgery, compared with the epsilon3 or epsilon2 allele. This is the first report of a possible genetic basis for acute renal impairment. These data may contribute to renal risk stratification for cardiac surgery and raise questions regarding apolipoprotein E and the pathophysiology of acute renal injury.     

Predicting delirium after vascular surgery: a model based on pre- and intraoperative data

OBJECTIVE: The aim of the study was to determine pre- and intraoperative risk factors for the development of postoperative delirium among patients undergoing aortic, carotid, and peripheral vascular surgery to predict the risk for postoperative delirium. SUMMARY BACKGROUND DATA: Although postoperative delirium after vascular surgery is a frequent complication and is associated with the need for more inpatient hospital care and longer length of hospital stay, little is known about risk factors for delirium in patients undergoing vascular surgery. METHODS: Pre-, intra-, and postoperative data were prospectively collected, including the first 7 postoperative days with daily follow-up by a surgeon and a psychiatrist of 153 patients undergoing elective vascular surgery. Delirium (Diagnostic and statistical Manual of Mental Disorders IV) was diagnosed by the psychiatrist. Multivariate linear logistic regression and a cross validation analysis were performed to find a set of parameters to predict postoperative delirium. RESULTS: Sixty patients (39.2%) developed postoperative delirium. The best set of predictors included the absence of supraaortic occlusive disease and hypercholesterinemia, history of a major amputation, age over 65 years, a body size of less than 170 cm, preoperative psychiatric parameters and intraoperative parameters correlated to increased blood loss. The combination of these parameters allows the estimation of an individual patients' risk for postoperative delirium already at the end of vascular surgery with an overall accuracy of 69.9%. CONCLUSIONS: Postoperative delirium after vascular surgery is a frequent complication. A model based on pre- and intraoperative somatic and psychiatric risk factors allows prediction of the patient's risk for developing postoperative delirium.     

Incidence of postoperative delirium is high even in a population without known risk factors

Purpose

Postoperative delirium is a recognized complication in populations at risk. The aim of this study is to assess the prevalence of early postoperative delirium in a population without known risk factors admitted to the ICU for postoperative monitoring after elective major surgery. The secondary outcome investigated is to identify eventual independent risk factors among demographic data and anesthetic drugs used.

Methods

An observational, prospective study was conducted on a consecutive cohort of patients admitted to our ICU within and for at least 24 h after major surgical procedures. Exclusion criteria were any preexisting predisposing factor for delirium or other potentially confounding neurological dysfunctions. Patients were assessed daily using the confusion assessment method for the ICU scale for 3 days after the surgical procedure. Early postoperative delirium incidence risk factors were then assessed through three different multiple regression models.

Results

According to the confusion assessment method for the ICU scale, 28 % of patients were diagnosed with early postoperative delirium. The use of thiopentone was significantly associated with an eight-fold-higher risk for delirium compared to propofol (57.1 % vs. 7.1 %, RR = 8.0, χ ² = 4.256; df = 1; 0.05 < p < 0.02).

Conclusion

In this study early postoperative delirium was found to be a very common complication after major surgery, even in a population without known risk factors. Thiopentone was independently associated with an increase in its relative risk.     

Apolipoprotein E polymorphism and outcome after closed traumatic brain injury: influence of ethnic and regional differences

OBJECT: The presence of the apolipoprotein E-epsilon4 (APOE-epsilon4) allele is reported to be associated with poor outcome after traumatic brain injury (TBI). This study was performed to determine if the presence of the APOE-epsilon4 allele influenced outcome in a cohort of black patients with TBI who had homogeneous neuropathological findings. METHODS: Venous blood was collected at the time of admission to determine the APOE genotype in black Zulu-speaking patients who presented with traumatic cerebral contusions. The frequency of the APOE-epsilon4 allele's appearance was correlated with outcome at a minimum of 6 months of follow up. Univariate and multivariate analyses were performed to determine independent risk factors and to control for confounding factors. In 110 black Zulu-speaking patients with traumatic cerebral contusions, genotypes for APOE were analyzed. Eleven of 45 (24.4%) with the APOE-epsilon4 allele experienced a poor outcome, compared with 10 (15.4%) of 65 without this allele (p = 0.34). Both patients with homozygous APOE-epsilon4 alleles experienced a good outcome (Glasgow Outcome Score 5). Univariate and multivariate analysis revealed no significant relationship in patients with the APOE-epsilon4 allele with regard to age, admission Glasgow Comas Scale score, contusion volume, type of neurosurgical management, and outcome. The risk of a poor outcome was, however, greater in patients with the APOE-epsilon4 allele (relative risk 1.59; 95% confidence interval 0.74-3.42). CONCLUSIONS: The authors recorded no relationship between APOE-epsilon4 allele status and outcome after TBI in black patients. Given the high regional susceptibility to the APOE gene, further studies, possibly even community-based investigations and studies conducted in other geographic areas, are probably warranted.     

Postoperative delirium in spine surgery.

BACKGROUND CONTEXT: Postoperative delirium is a great concern in the treatment of hip fracture. However, there have been no reports regarding the postoperative delirium in spine surgery. PURPOSE: To determine the incidence and risk factors for postoperative delirium in the patients who have had spine surgery. STUDY DESIGN/SETTING: The incidence and intraoperative risk factors of postoperative delirium were retrospectively examined in patients who had spine surgery during a 3-year period. PATIENT SAMPLE: Three hundred forty-one patients who underwent spine surgery from 2000 to 2002 were included. METHODS: The presence of delirium was determened by the Confusion Assessment Method. Laboratory data were checked preoperatively, at 1 day and 1 week postoperatively. The prognosis of postoperative delirium was evaluated. RESULTS: Postoperative delirium was found in 13 patients; all of them were in their 70's or 80's. The incidence of delirium was 12.5% in the patients over 70 years old. Hemoglobin and hematocrit levels at 1 day after surgery in the delirium group were significantly lower than those in the control group. One patient had persistent cognitive dysfunction after surgery. Two patients who developed postoperative delirium died during the follow-up period. CONCLUSION: Low concentrations of hemoglobin and hematocrit 1 day after surgery were risk factors for postoperative delirium. As delirium is thought to represent not only brain dysfunction, but also impaired general physical condition, careful observation is necessary for the management of patients with postoperative delirium.     

全凭静脉麻醉下脊柱手术患者术后谵妄的危险因素

目的 筛选全凭静脉麻醉下脊柱手术患者发生术后谵妄的危险因素.方法 择期行脊柱手术患者200例,年龄18～70岁,根据术后3 d内是否发生谵妄分为术后谵妄组和非术后谵妄组.可疑危险因素进行组间比较后,将差异有统计学意义的因素进行logistic回归分析,筛选发生术后谵妄的危险因素.结果 39例患者术后发生谵妄,发生率为19.5%.logistic回归分析结果显示,年龄、术中失血量、经常饮酒是发生术后谵妄的独立危险因素(P＜0.05).相对危险度依次为1.882、0.999、1.715.结论 老龄、术中大量失血、长期饮酒是全凭静脉麻醉下脊柱手术患者发生术后谵妄的危险因素.     

Pathogenesis of and management strategies for postoperative delirium after hip fracture: a review

BACKGROUND: Postoperative delirium is a frequent and serious complication in elderly patients following operation for hip fracture, leading to an increased risk of complications. The pathophysiological mechanisms are unresolved, but probably multifactorial. The purpose of this review is to summarize current knowledge about the pathogenesis of postoperative delirium with a view to finding strategies for prevention and management. METHOD: We conducted an Internet search through the Medline database (1966-March 2003) and supplemented it with a manual search. We included 12 studies which specifically discussed pathogenic factors or interventions against postoperative delirium following operation for hip fracture. RESULTS: 1,823 patients were included with an average incidence of delirium of 35%. We concentrated on pre-, intra-, and postoperative risk factors. Only advanced age and dementia met our fixed criterion of "strong evidence" for a significant association. Hence, from the studies that we reviewed we were unable to find intraoperative or postoperative factors with "strong evidence" for a significant association with delirium. INTERPRETATION: Postoperative delirium is a serious complication. The pathophysiology leading to delirium after hip fracture surgery still remains to be clarified and no single drug or surgical regimen has proven to be preventive. This calls for more detailed investigations of the differential role of different pathogenic mechanisms, as well as an aggressive multimodal approach to enhance recovery and reduce morbidity, as has proven to be successful in a variety of elective surgical procedures. Such multimodal interventional studies represent a major task for orthopedic departments in collaboration with anesthesiologists, geriatricians, physiotherapists and nursing staff.     

Apolipoprotein E genotype and neurodevelopmental sequelae of infant cardiac surgery

BACKGROUND: There has been increasing recognition of adverse neurodevelopmental sequelae in some children after repair of congenital heart defects. Even among children with the same cardiac defect, significant interindividual variation exists in developmental outcome. Polymorphisms of apolipoprotein E have been identified as a risk factor for worse neurologic recovery after central nervous system injury. METHODS: A single-institution prospective study of patients 相似文献   

Meta-analysis of factors which influence delirium following cardiac surgery

Abstract Background: The aim of this study is to determine the risk factors of delirium after cardiac surgery. Methods: A systematic literature search of MEDLINE, EMBASE, the Cochrane Library, and Science Citation Index limited to 2008 to 2011 and review of studies was conducted. Eligible studies were of randomized controlled trials or cohort studies, using delirium assessment tool, reporting at least one risk factor associated with delirium, and available to full text. Results: The search identified 106 potentially relevant publications; only 25 met selection criteria. Our systematic review revealed 33 risk factors: 17 predisposing and 16 precipitating factors for delirium after elective cardiac surgery. The most established predisposing risk factors were age, depression, and history of stroke, cognitive impairment, diabetes mellitus, and atrial fibrillation. The most established precipitating risk factors were duration of surgery, prolonged intubation, surgery type, red blood cell transfusion, elevation of inflammatory markers and plasma cortisol level, and postoperative complications. Moreover, sedation with dexmedetomidine may significantly predict the absence of postoperative delirium. Conclusions: Postoperative delirium is related to several risk factors following cardiac surgery. Sedation with dexmedetomidine and fast‐track weaning protocols may decrease the incidence of delirium in cardiac surgical patients. (J Card Surg 2012;27:481‐492)     

全麻下血管化游离皮瓣修复术后患者谵妄的危险因素

目的 筛选全麻下血管化游离皮瓣修复术后患者谵妄的危险因素.方法 择期行血管化游离皮瓣修复手术的患者216例,年龄18～80岁,根据术后5d内是否发生谵妄分为术后谵妄组和非术后谵妄组.可能的危险因素进行组间比较后,将差异有统计学意义的因素进行logistic回归分析,筛选发生术后谵妄的危险因素.结果 logistic回归分析结果显示,酗酒、术后睡眠紊乱和高龄是术后谵妄的独立危险因素(P<0.05),相对危险度依次为17.066,5.647和1.047.结论 高龄、酗酒史和术后睡眠紊乱是全麻下血管化游离皮瓣修复术后患者谵妄的危险因素.     

心脏手术后谵妄的危险因素分析及预测模型构建

目的 探讨心脏手术患者术后谵妄(POD)的危险因素,根据危险因素构建预测模型并评估其预测效能。
方法 本研究为回顾性病例-对照研究。收集2016年5月至2019年5月行心脏手术治疗的患者3 397例临床资料,提取性别、年龄、吸烟史、饮酒史、高血压病史、糖尿病史、高脂血症病史、脑血管疾病史、手术时间、心肺转流（CPB）时间、主动脉阻断时间、术中连续有创动脉血压值、术中出血量、术中麻醉药物使用情况、入ICU时Hb、白细胞计数、氧合指数（PaO2/FiO2）、血乳酸值、呼吸机使用时间、血管活性药物使用情况、术后左心室射血指数（LVEF）等临床指标,采用单因素分析评估上述指标与POD的相关性。采用逐步Logistic回归进行临床指标筛选并构建预测模型,绘制模型列线图,计算预测模型的受试者工作特征（ROC）曲线下面积（AUC）以及最佳阈值下的敏感性和特异性。
结果 有186例（5.48%）患者术后出现谵妄。与非谵妄患者比较,谵妄患者年龄、脑血管疾病和高血压病史比例、术中低血压比例、术中血压变异率、术中丙泊酚用量、术中出血量、术后乳酸值、术后白细胞显著增高的比例、术后左心室收缩功能不全（LVEF<50%）的比例以及术后应用肾上腺素和去甲肾上腺素比例明显增加（P<0.05）,手术时间和CPB时间、术中低血压时间以及术后机械通气时间明显延长（P<0.05）,术后氧合指数和Hb明显降低（P<0.05）。逐步Logistic回归分析显示,老年、脑血管疾病史、手术时间长、术中血压变异率大、术后Hb<100 g/L、机械通气时间延长以及左心室收缩功能不全、应用去甲肾上腺素是心脏手术后谵妄的独立危险因素。应用这些危险因素构建预测模型,AUC为0.932（95%CI 0.897～0.967）,敏感性78.2%,特异性93.5%。
结论 老年、脑血管疾病史、手术时间、术中血压变异率、术后Hb<100 g/L、机械通气时间延长以及左心室收缩功能不全、应用去甲肾上腺素是心脏手术后谵妄的独立危险因素,基于这些危险因素构建的模型可较好地预测心脏手术后谵妄的发生,为早期干预治疗提供参考。     

Durchgangssyndrome nach gefäßchirurgischen Operationen

INTRODUCTION: Postoperative delirium is a common psychic disturbance occurring acutely after various surgical procedures and typically presenting with a fluctuating course. These patients' recovery takes longer. In this study we analyze the incidence of postoperative delirium in patients undergoing vascular surgery and try to identify risk factors for its development. METHODS: Patients undergoing elective arterial operations were included. Their medical history, the specific vascular diagnosis and operation performed, the medication and laboratory data were monitored. Additionally the patients were preoperatively interviewed by a psychiatrist. Intraoperatively the drugs, infusions, possible transfusions, blood gases and pressures were monitored, as were the times of surgery and anesthesia. Postoperatively patients were seen daily by the psychiatrist and the surgeon for at least 7 days. Postoperative delirium was diagnosed according to DSM IV criteria, and mild, moderate and severe delirium were distinguished. RESULTS: Fifty-four patients entered the study. Twenty-one (38.9%) developed postoperative delirium (11 mild, 2 moderate, 8 severe). Patients with aortic operations developed delirium more frequently than those with non-aortic procedures(55.5 vs 22.2%, n = 27 each). Some preexisting diseases (hearing disturbance) increased the probability of postoperative delirium, while age was not identified as a risk factor. General psychopathological and depressive disturbances increased the likelihood of postoperative delirium. Patients who had a severe intraoperative course developed postoperative delirium more frequently. This was not seen in the absolute time of surgery or anesthesia nor in the intraoperative development of blood pressure or intraarterial gases, which did not differ between patients with and without postoperative delirium. More reliable parameters were an increased intraoperative need for crystalloid volume, intra- or postoperatively decreased hemoglobin values (Hb < 10 g/dl) and the development of acidosis that had to be treated. Patients with delirium had serious complications more often (8/21 = 38.1% vs 6/33 = 18.2%) and needed Intensive Care treatment longer (2.7 vs 2.1 days, only aortic surgery 3.2 vs 2.4 days). CONCLUSIONS: Postoperative delirium after vascular surgery is frequent. Patients undergoing aortic surgery, with specific concomitant medical disease, psychopathological disturbances and a severe intraoperative course, are at risk of developing postoperative delirium.     

Melatonin for treatment and prevention of postoperative delirium.

Postoperative delirium is a common problem associated with increased morbidity and mortality, prolonged hospital stay, additional tests and consultations and therefore, increased cost (1,2). The reported incidence of delirium or confusion after surgery ranges from 8% to 78% (2,3-5), depending on methods and population studied. The elderly seem to be at significantly increased risk for this complication. Sleep-wake cycle disruption has been associated with delirium and behavioral changes (5) and sleep deprivation can even result in psychosis (6). Environmental changes (i.e., hospital stay), medications, and general anesthesia can affect the sleep-wake cycle (3,4). Plasma melatonin levels, which play an important role in the regulation of the sleep-wake cycle, are decreased after surgery (18) and in hospitalized patients (7,11). We report the successful use of melatonin in treating severe postoperative delirium unresponsive to antipsychotics or benzodiazepines in one patient. In another patient with a history of postoperative delirium, melatonin was used to prevent another episode of delirium after repeat lower extremity surgery. IMPLICATIONS: Postoperative delirium or confusion after surgery is a common problem associated with complications and death. Delirium has been linked to sleep-wake cycle disruption. Melatonin levels, which play an important role in regulating the sleep-wake cycle, are decreased after surgery. Two cases are presented where melatonin was used to treat and prevent postoperative delirium.     

Preliminary Report on the Association of Apolipoprotein E Polymorphisms, with Postoperative Peak Serum Creatinine Concentrations in Cardiac Surgical Patients

Background: Renal dysfunction after cardiac surgery occurs in up to 8% of patients and is associated with major increases in morbidity, mortality, and cost. Genetic polymorphisms have been implicated as a factor in the progression of chronic renal disease, but a genetic basis for the development of acute renal impairment has not been investigated. The authors therefore tested the hypothesis that apolipoprotein E alleles are associated with different postoperative changes in serum creatinine after cardiac surgery.

Methods: The authors performed a prospective observational study with use of data from 564 coronary bypass surgical patients who were enrolled in an ongoing investigation of apolipoprotein E genotypes and organ dysfunction at a university hospital between 1989-1999. Renal function was assessed among apolipoprotein E genotype groups by comparisons of preoperative (CrPre), peak in-hospital postoperative (CrMax) and perioperative change (DCr) in serum creatinine values.

Results: The [epsilon]4 allele grouping (E2 = 2/2,2/3,2/4; E3 = 3/3; E4 = 3/4,4/4) was associated with a smaller increase in postoperative serum creatinine (perioperative change: E4, +0.17; E3, +0.26; E4, +0.27 mg/dl) and a lower peak postoperative creatinine than the [epsilon]2 and [epsilon]3 in univariate and multivariate analysis (peak in-hospital postoperative serum creatinine multivariate P = 0.015 vs. [epsilon]3, P = 0.038 vs. [epsilon]2). There was no difference in baseline creatinine among allele groups.     

Durchgangssyndrome nach gefäßchirurgischen Operationen Zwischenergebnisse einer prospektiven Untersuchung

Introduction: Postoperative delirium is a common psychic disturbance occurring acutely after various surgical procedures and typically presenting with a fluctuating course. These patients' recovery takes longer. In this study we analyze the incidence of postoperative delirium in patients undergoing vascular surgery and try to identify risk factors for its development. Methods: Patients undergoing elective arterial operations were included. Their medical history, the specific vascular diagnosis and operation performed, the medication and laboratory data were monitored. Additionally the patients were preoperatively interviewed by a psychiatrist. Intraoperatively the drugs, infusions, possible transfusions, blood gases and pressures were monitored, as were the times of surgery and anesthesia. Postoperatively patients were seen daily by the psychiatrist and the surgeon for at least 7 days. Postoperative delirium was diagnosed according to DSM IV criteria, and mild, moderate and severe delirium were distinguished. Results: Fifty-four patients entered the study. Twenty-one (38.9%) developed postoperative delirium (11 mild, 2 moderate, 8 severe). Patients with aortic operations developed delirium more frequently than those with non-aortic procedures(55.5 vs 22.2%, n=27 each). Some preexisting diseases (hearing disturbance) increased the probability of postoperative delirium, while age was not identified as a risk factor. General psychopathological and depressive disturbances increased the likelihood of postoperative delirium. Patients who had a severe intraoperative course developed postoperative delirium more frequently. This was not seen in the absolute time of surgery or anesthesia nor in the intraoperative development of blood pressure or intraarterial gases, which did not differ between patients with and without postoperative delirium. More reliable parameters were an increased intraoperative need for crystalloid volume, intra – or postoperatively decreased hemoglobin values (Hb <10 g/dl) and the development of acidosis that had to be treated. Patients with delirium had serious complications more often (8/21=38.1% vs 6/33=18.2%) and needed Intensive Care treatment longer (2.7 vs 2.1 days, only aortic surgery 3.2 vs 2.4 days). Conclusions: Postoperative delirium after vascular surgery is frequent. Patients undergoing aortic surgery, with specific concomittant medical disease, psychopathological disturbances and a severe intraoperative course, are at risk of developing postoperative delirium.