Risk Of Postoperative Delirium Research Articles

SF-36 scores predict postoperative delirium after surgery for cervical spondylotic myelopathy.

Cervical spondylotic myelopathy (CSM) is one of the most common causes of spinal cord dysfunction. Surgery for CSM is generally effective, but postoperative delirium is a potential complication. Although there have been some studies that investigated postoperative delirium after spine surgery, no useful tool for identifying high-risk patients has been established, and it is unknown if 36-Item Short Form Health Survey (SF-36) scores can predict postoperative delirium. The objective of this study was to evaluate the correlation between preoperative SF-36 scores and postoperative delirium after surgery for CSM. Sixty-seven patients who underwent surgery for CSM at the authors' institution were enrolled in this study. Medical records of these patients were retrospectively reviewed. Patient background, preoperative laboratory data, preoperative SF-36 scores, the preoperative Japanese Orthopaedic Association (JOA) score for the evaluation of cervical myelopathy, and perioperative factors were selected as potential risk factors for postoperative delirium. These factors were evaluated using univariable and multivariable logistic regression analysis. Ten patients were diagnosed with postoperative delirium. Univariable analysis revealed that the physical functioning score (p = 0.01), general health perception score (p < 0.01), and vitality score (p < 0.01) of the SF-36 were significantly lower in patients with postoperative delirium than in those without. The total number of medications was significantly higher in the delirium group compared with the no-delirium group (p = 0.02). In contrast, there were no significant differences between the delirium group and the no-delirium group in cervical JOA scores (p = 0.20). Multivariable analysis revealed that a low general health perception score was an independent risk factor for postoperative delirium (p = 0.02; odds ratio 0.810, 95% confidence interval 0.684-0.960). Some of the SF-36 scores were significantly lower in patients with postoperative delirium than in those without. In particular, the general health perception score was independently correlated with postoperative delirium. SF-36 scores could help identify patients at high risk for postoperative delirium and aid in the development of prevention strategies.

Intraoperative ketamine may increase risk of post-operative delirium after complex spinal fusion for adult deformity correction.

For complex surgery, intraoperative ketamine administration is readily used to reduce post-operative pain. However, there have been a few studies suggesting that intraoperative ketamine may have deleterious effects and impact post-operative delirium. Therefore, we sought to identify the impact that intraoperative ketamine has on post-operative outcomes after complex spinal surgery involving ≥5 level fusions. The medical records of 138 adult (≥18 years old) spine deformity patients undergoing elective, primary complex spinal fusion (≥5 level) for deformity correction at a major academic institution from 2010 to 2015 were reviewed. We identified 98 (71.0%) who had intraoperative ketamine administration and 40 (29%) who did not (Ketamine-Use: n=98; No-Ketamine: n=40). Patient demographics, comorbidities, intra- and post-operative complication rates were collected for each patient. The primary outcome investigated in this study was the rate of post-operative delirium. A multivariate nominal-logistic regression analysis was used to determine the independent association between intraoperative ketamine and post-operative delirium. Patient demographics and comorbidities were similar between both cohorts, including age, gender, and BMI. The median number of fusion levels operated, length of surgery, estimated blood loss, and proportion of patients requiring blood transfusions were similar between both cohorts. Postoperative complication profile was similar between the cohorts, except for the Ketamine-Use cohort having significantly higher proportion of patients experiencing delirium (Ketamine-Use: 14.3% vs. No-Ketamine: 2.6%, P=0.047). In a multivariate nominal-logistic regression analysis, intraoperative Ketamine-Use was independently associated with post-operative delirium (OR: 9.475, 95% CI: 1.026-87.508, P=0.047). Our study suggests that the intraoperative use of ketamine may increase the risk of post-operative delirium. Further studies are necessary to understand the physiological effect intraoperative ketamine has on patients undergoing complex spinal fusions in order to better overall patient care and reduce healthcare resources.

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

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

The impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients: retrospective before-after observational study.

To assess the impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients, we conducted retrospective before-after study in a tertiary teaching hospital. We examined all adult patients admitted ICU after an elective operation for head and neck cancer, or esophageal cancer from February 2014 to January 2017. From February 2014 to July 2015, patients were administered hypotonic fluid (sodium; 35mmol/L) as the National Institute for Health and Care Excellence (NICE) have recommended. From August 2015 to January 2017, patients were administered isotonic fluid (sodium; 140mmol/L). We defined the incidence of delirium as the primary outcome. The delirium was defined as the Intensive Care Delirium Screening Checklist during the ICU stay ≥ 4. A propensity score-matched model was used to adjust confounders. As postoperative intravenous maintenance fluid, hypotonic fluid was administered to 119 patients and isotonic fluid was administered to 92 patients. Among those total cohorts, the incidence of postoperative delirium in the hypotonic group was 21.8%, which was significantly higher than that (9.8%) in the isotonic group (p = 0.019). After propensity score matching, we selected 77 patients in each group. The incidence of delirium during the ICU stay in the hypotonic group was 26.0%, which was significantly higher than the incidence of 11.7% in the isotonic group (p = 0.023). In this study, the use of postoperative hypotonic maintenance fluid was associated with a higher risk of postoperative delirium than that when isotonic maintenance fluid was used.

Association of Duration of Surgery With Postoperative Delirium Among Patients Receiving Hip Fracture Repair

Postoperative delirium in older adults receiving hip fracture surgery is associated with morbidity and increased health care costs, yet little is known of potential modifiable factors that may help limit the risks. To use population-wide individual-level data on the duration of hip fracture surgery to determine whether prolonged surgical times and type of anesthesia are associated with an increased risk of postoperative delirium. This retrospective population-based cohort study analyzed patients aged 65 years and older receiving hip fracture surgery between April 1, 2009, and March 30, 2017, at 80 hospitals in Ontario, Canada. Generalized estimated equations with logistic regression analysis were used to determine the relationship between procedure duration, type of anesthesia, and the occurrence of postoperative delirium. Restricted cubic splines were also generated to visualize this relationship. Data analysis was conducted from July to October 2018, revision in January 2019. Surgery duration, measured as the total time in the operating room. A diagnosis of postoperative delirium during hospitalization. Among 68 131 patients with surgically managed hip fracture (median [interquartile range] age, 84 [78-89] years; 72% women) identified, 7150 patients experienced postoperative delirium. In total, 26 853 patients (39.4%) received general anesthesia. Receiving general anesthesia was associated with a slightly higher rate of postoperative delirium compared with not receiving general anesthesia (2943 [11.0%] vs 4207 [10.2%]; P = .001). The risk for delirium increased with increased surgical duration-every 30-minute increase in the duration of surgery was associated with a 6% increase in the risk for delirium (adjusted odds ratio, 1.06; 95% CI, 1.03-1.08; P < .001). Prolonged surgical duration was associated with a higher incidence of postoperative delirium, and the risk was higher was in patients who had received general anesthesia (adjusted odds ratio, 1.08; 95% CI, 1.04-1.12; P < .001) than in those patients who did not receive GA (adjusted odds ratio, 1.04; 95% CI, 1.01-1.08; P = .01). Among older adults receiving hip fracture surgery, both an increased duration of surgery and receiving a general anesthetic were associated with an increased risk for postoperative delirium.

Intraoperative reduction of vasopressors using processed electroencephalographic monitoring in patients undergoing elective cardiac surgery: a randomized clinical trial.

Intraoperative vasopressor and fluid application are common strategies against hypotension. Use of processed electroencephalographic monitoring (pEEG) may reduce vasopressor application, a known risk factor for organ dysfunction, in elective cardiac surgery patients. Randomized single-centre clinical trial at Jena University Hospital. Adult patients operated on cardiopulmonary bypass or off-pump coronary artery bypass grafting were randomised to receive anesthesia with visible or blinded pEEG using Narcotrend™. In blinded-Narcotrend (NT) depth of anesthesia was extrapolated from clinical signs, hemodynamic response and anesthetic concentration, supplemented by target indices between 37 and 64 in the visible-NT group. Intraoperative norepinephrine requirement (primary endpoint), fluid balance, extubation time, delirium occurrence and adverse events were evaluated. Patients of the intent-to-treat population (visible-NT: n = 123, blinded-NT: n = 122) had similar patient and procedural characteristics. Adjusted for type of surgery intraoperative Norepinephrine application was significantly reduced in visible-NT (n = 120, robust mean of cumulative dose 4.71µg/kg bodyweight) compared to blinded-NT patients (n = 119, 6.14µg/kg bodyweight) (adjusted robust mean difference 1.71 (95% CI 0.33-3.10) µg/kg bodyweight). Although reduction in patients operated on cardiopulmonary bypass was higher the interaction was not significant in post-hoc subgroup analysis. Intraoperative fluid balance was similar among both groups and strata. Extubation time was non-significantly lower in visible than in blinded-NT group. Overall postoperative delirium risk was 16.4% without differences among the groups. Adverse events-sudden movement/coughing, perspiration or hypertension-occurred more often with visible-NT, while one blinded-NT patient experienced intraoperative awareness. Titration of depth of anesthesia in elective cardiac surgery patients using pEEG allows to reduce application of norepinephrine.

Incidence and predictors of postoperative delirium in the older acute care surgery population: a prospective study

Among older inpatients, the highest incidence of delirium is within the surgical population. Limited data are available regarding postoperative delirium risk in the acute care surgical population. The purpose of our study was to establish the incidence of and risk factors for delirium in an older acute care surgery population. Patients aged 65 years or more who had undergone acute care surgery between April 2014 and September 2015 at 2 university-affiliated hospitals in Alberta were followed prospectively and screened for delirium by means of a validated chart review method. Delirium duration was recorded. We used separate multivariable logistic regression models to identify independent predictors for overall delirium and longer episodes of delirium (duration ≥ 48 h). Of the 322 patients included, 73 (22.7%) were identified as having experienced delirium, with 49 (15.2%) experiencing longer episodes of delirium. Postoperative delirium risk factors included Foley catheter use, intestinal surgery, gallbladder surgery, appendix surgery, intensive care unit (ICU) admission and mild to moderate frailty. Risk factors for prolonged postoperative delirium included Foley catheter use and mild to moderate frailty. Surgical approach (open v. laparoscopic) and overall operative time were not found to be significant. In keeping with the literature, our study identified Foley catheter use, frailty and ICU admission as risk factors for delirium in older acute care surgical patients. We also identified an association between delirium risk and the specific surgical procedure performed. Understanding these risk factors can assist in prevention and directed interventions for this high-risk population.

Lower risk of postoperative delirium using laparoscopic approach for major abdominal surgery.

A laparoscopic approach is increasingly being used for major abdominal surgeries and is reportedly associated with a lower incidence of postoperative complications. However, the association of laparoscopic approach and postoperative delirium remains unclear. We aimed to retrospectively investigate risk factors for postoperative delirium after abdominal surgery particularly assessing the association between a laparoscopic approach and postoperative delirium. We retrospectively studied 801 patients who underwent major abdominal surgery between April 2012 and December 2013. Among these, 181 (22.6%) patients underwent a laparoscopic and 620 (77.4%) patients underwent an open procedure. A Cox proportional hazard model analysis was used to identify risk factors for the development of postoperative delirium or overall survival within 180 days after surgery. Cumulative incidence of postoperative delirium was assessed using a propensity score-matching analysis. Postoperative delirium occurred in 56 patients (7.0%). A Multivariate Cox proportional hazard model analysis revealed that a laparoscopic approach reduced the risk of postoperative delirium [hazard ratio (HR) 0.30, 95% confidence interval (CI) 0.07-0.84, p = 0.019]. Postoperative delirium was associated with worse overall survival within 180 days (HR 4.91, 95% CI 1.96-12.22, p = 0.001) after adjusting for other confounders using the Cox proportional hazard model analysis. Patients who developed postoperative delirium showed worse outcomes including higher rate of morbidity except delirium (p < 0.001), longer hospitalization (p < 0.001), and post-discharge institutionalization (p < 0.001). After propensity score-matching, cumulative incidence rates of postoperative delirium were significantly lower in the laparoscopic group compared to the open group (30-day cumulative incidence rate, 1.7% vs. 7.8%, p = 0.006). The risk of postoperative delirium after major abdominal surgery is reduced using laparoscopic approach. Postoperative delirium should be prevented as it precipitates adverse postoperative events.

Moderate alcohol consumption, intraoperative bleeding and postsurgical pain may increase the risk of postoperative delirium in patients undergoing radical retropubic prostatectomy

Background/Aim. The incidence of postoperative delirium (POD) after non-cardiac surgery is a problem not often recognized by many anesthesiologists. The objective of our study was to detect POD and its possible cause, in patients undergoing radical retropubic prostatectomy (RRP) under general anesthesia. Methods. After Ethical Committee approval, we enrolled 80 patients, ASA (the American Society of Anestesiology) status II, scheduled to undergo RRP un-der general anesthesia, in a prospective study. All patients completed MMSE tests (the Folstein Mini Mental State Ex-am) the evening before, and 48 hours after the surgery. Assessment for the presence and severity of delirium was per-formed using CAM (the Confusion Assessment Method), and an assessment of the degree of agitation and sedation using RASS (the Richmond Agitation and Sedation Scale). Results. The average preoperative MMSE score (28.59 ? 1.04) significantly decreased following the surgery (27.74 ? 1.52) (p &lt; 0.0001). The average postoperative MMSE score trend descended in correlation to intraoperative bleeding (p = 0.036). The patients with higher pain scores had significant decline in MMSE after the surgery (28.75 vs. 26.25; p &lt; 0.001). Five patients were considered positive for delirium, and four of them reported regular alcoholic drinks intake (&gt; 1 drink per day) preoperatively (p &lt; 0.0001). Based on RASS score, 13 patients (16.3%) were agitated or sedated, and they had statistically significantly higher intraoperative bleeding (p &lt; 0.001). Conclusion. Results of this study emphasize the importance of proper preoperative evaluation; especially regarding the alcohol consumption since all the patients that developed POD reported moderate alcohol consumption. Further-more, greater intraoperative bleeding and postoperative pain scores did not influence the occurrence of delirium, but resulted in lower postoperative MMSE scores, which high-lights the importance of adequate intraoperative treatment of patients during surgery and anesthesia in order to reduce the risk of developing POD.

Does the melatonin receptor 1B gene polymorphism have a role in postoperative delirium?

IntroductionPatients undergoing cardiac surgery are at high risk for postoperative delirium, which is associated with longer hospital and intensive care lengths of stays, increased morbidity and mortality. Because sleep disturbances are common in delirium, melatonin has been an area of interest in the treatment of delirium. The rs10830963 single nucleotide polymorphism of the melatonin receptor 1B gene can cause pathological dysfunction of this receptor and is associated with delayed morning offset of melatonin. We hypothesized patients undergoing aortic cardiac surgery who have the risk genotype of a melatonin receptor 1B polymorphism would have a higher incidence of postoperative delirium.MethodsNinety-eight patients undergoing aortic root or valve surgery underwent analysis for melatonin receptor 1B single nucleotide polymorphism, rs10830963. Using a validated method, CHART-DEL, all charts were retrospectively reviewed and scored for the presence of delirium while blinded to the results of the melatonin receptor 1B gene polymorphism.ResultsGenotyping for melatonin receptor 1B polymorphism was acceptable in 76 subjects of European descent of which 18 (23.7%) had delirium. Four of seven subjects with the risk genotype had delirium versus only 20.3% of subjects without the risk genotype. This carried an odds ratio of 5.2 (1.0, 26.1), p = 0.050.ConclusionThis observation suggests a role of the risk genotype of a melatonin receptor 1B polymorphism in the development of postoperative delirium. These hypotheses generating results warrant further prospective studies in a larger cohort group with delirium, circadian rhythm and melatonin assessments.

Preventive effects of early postoperative cognitive stimulation on delirium after radical gastrectomy in elderly patients with gastric cancer

Objective To explore the preventive effects of early postoperative cognitive stimulation on delirium after radical gastrectomy in elderly patients with gastric cancer. Methods Totally 78 elderly patients who received radical gastrectomy from January to October 2017 were selected by convenient sampling and divided into the control group (n=39) and the observation group (n=39) according to the random number table. Patients in the control group received conventional nursing care for gastric cancer patients, while patients in the observation group received cognitive interventions on this basis. The Confusion Assessment Method-Chinese Revision (CAM-CR) , Self-Anxiety Scale (SAS) and Satisfaction Questionnaire were used to evaluate the effects of the interventions. Results The morbidity of delirium postoperatively in the observation group was 5.13%, lower than that of the control group (χ2=5.186, P=0.023) , which was 23.08%. The SAS score of the observation group was (47.36±5.28) after the interventions, lower than that of the control group (t=2.311, P=0.024) , which was (50.23±5.68) . The satisfaction score in the treatment group before discharge was (92.46±3.35) , higher than that of the control group (t=6.335, P<0.001) , which was (87.64±3.37) . Conclusions Elderly patients with gastric cancer are at high risk of postoperative delirium. And early cognitive stimulation can effectively reduce the incidence of delirium, which is worth promoting in clinical practice. Key words: Aged; Gastric neoplasms; Delirium; Cognition

Balancing intubation time with postoperative risk in cardiac surgery patients - a retrospective cohort analysis.

IntroductionIntubation time in patients undergoing cardiac surgery may be associated with increased mortality and morbidity. Premature extubation can have serious adverse physiological consequences. The aim of this study was to determine the influence of intubation time on morbidity and mortality in patients undergoing cardiac surgery.MethodsWe performed a retrospective analysis of data on 1,904 patients undergoing isolated coronary artery bypass grafting (CABG) and stratified them by duration of intubation time after surgery – 0–6, 6–9, 9–12, 12–24 and over 24 hours. Postoperative complications risk analysis was performed using multivariate logistic regression analysis for patients extubated ≤12 and >12 hours.ResultsIntubation percentages in each time cohort were as follows: 0–6 hours – 7.8%, 6–9 hours – 17.3%, 9–12 hours – 26.8%, 12–24 hours – 44.4% and >24 hours – 3.7%. Patients extubated ≤12 hours after CABG were younger, mostly males, more often smokers, with lower preoperative risk. They had lower 30-day mortality (2.02% vs 4.59%, P=0.002), shorter hospital stay (7.68±4.49 vs 9.65±12.63 days, P<0.001) and shorter intensive care unit stay (2.39 vs 3.30 days, P<0.001). Multivariate analysis showed that intubation exceeding 12 hours after CABG increases the risk of postoperative delirium (OR 1.548, 95% CI 1.161–2.064, P=0.003) and risk of postoperative hemofiltration (OR 1.302, 95% CI 1.023–1.657, P=0.032).ConclusionResults indicate that risk of postoperative complications does not increase until intubation time exceeds 12 hours. Shorter intubation time is seen in younger, men and smokers. Intubation time >12 hours is a risk factor for postoperative delirium and hemofiltration after cardiac surgery.

Risk factors associated with delirium for patients with hip fracture under the orthogeriatric unit mode

Objective: To explore postoperative delirium (POD)risk factors for geriatric patients who suffered hip fracture under the care of orthogeriatric unit mode. Methods: Patients aged 65 years or older, who were admitted to the orthogeriatric unit in Beijing Jishuitan Hospital from April to October 2017 for hip fracture surgery, were eligible for this prospective cohort study. After univariable analysis, significant risk factors associated with POD were further evaluated with multivariable analysis, to establish independent risk factors associated with POD. Results: A total of 203 patients with an average age of 80(65-96)years were enrolled in the study. The overall incidence of POD was 9.4%(19/203)in which hyperactive and hypoactive type accounting for 84.2%(16/19)and 15.8%(3/19), respectively. Significant difference was found between POD and non-POD groups in patients' age (P=0.003), albumin(P=0.006), TSH(P=0.018), PaCO(2) level(P=0.003), visual analogue scale (VAS )both at rest (P=0.013)and movement(P=0.010) on post-operative day 1.The further Logistic stepwise regression analysis showed that significant differences existed between groups in age(P=0.027), albumin(P=0.003), PaCO(2)(P=0.014)and VAS at rest(P=0.002). Conclusion: The independent risk factors of POD in geriatric patients undergoing hip fracture under the orthogeriatric unit mode include patients' age, pre-operative albumin as well as PaCO(2) level and post-operative VAS at rest.

Predictive nomogram for postoperative delirium in elderly patients with a hip fracture

To evaluate the risk factors for the development of postoperative delirium and design a predictive nomogram for the prevention of delirium in elderly patients with a hip fracture, we retrospectively studied 825 patients who sustained a femoral neck fracture from January 2005 to December 2015. Independent risk factors for developing delirium within 6 months of surgery were identified using multivariable logistic regression analyses. A predictive nomogram model was built based on the results, and the discrimination and calibration were determined by C-index and calibration plot. Of the 825 patients who met inclusion criteria, 118 (14.3%) developed postoperative delirium. According to the results, preoperative cognitive impairment (OR, 4.132, 95% CI, 1.831 to 9.324, P＜0.001), multiple medical comorbidities (OR, 1.452, 95% CI, 0.958–2.202, P = 0.079), ASA classification (OR, 1.655, 95% CI, 1.073–2.553, P = 0.023), transfusion exceeding 2 units of red blood cell (OR, 1.599, 95% CI, 1.043–2.451, P = 0.035), and intensive care (OR, 1.817, 95% CI, 1.127–2.930, P = 0.014) were identified to be the independent predictors of the development of postoperative delirium. The risk of postoperative delirium increased with the increasing risk score of predictive nomogram, and the C-index was 0.67 (0.62 - 0.72). The calibration showed that the predicted probabilities of delirium in the predictive nomogram were close to the observed frequency of delirium, and the decision curve analysis confirmed the clinical utility of the nomogram when the threshold probabilities were between 8% and 35% due to the net benefit.

Prophylaxis of postoperative delirium in elderly critically ill patients

Background Delirium is associated with substantial morbidity in elderly hospitalized patients, while since diagnosed, the delirium has scarcely been effectively treated. Therefore, it is of great importance to prevent postoperative delirium in elderly patients who are admitted to ICU. However, currently available treatments cannot optimally prevent the development of delirium in these patients. Objective To review the intervention strategies to prevent the postoperative delirium in elderly critically ill patients. Content To prevent postoperative delirium in elder patients in ICU, some clinical study centers used pharmacological (haloperidol, atypical antipsychotics, dexmedetomidine, melatonin) or non-pharmacological (reorientation, entertainment, family support, etc) strategies. Some of the drugs not only could reduce risk of post-operative delirium, but also cause emotional, cardiac or circadian side-effects. Trend The use of antipsychotics and dexmedetomidine has consensus efficacy to reduce the risk of postoperative delirium in elderly critically ill patients. However, further investigations are warranted to optimize the medication to mitigate their cardiac side-effects. Key words: Elderly; Critical illness; Postoperative delirium

The influence of oxygen delivery during cardiopulmonary bypass on the incidence of delirium in CABG patients; a retrospective study.

Introduction:Postoperative delirium is the most common neurological complication of cardiac surgery. Hypoxia has been shown to increase the risk of postoperative delirium. The possibility to continuously monitor oxygen delivery (DO2) during cardiopulmonary bypass (CPB) offers an adequate approximation of the oxygen status in a patient. This study investigates the role of oxygen delivery during cardiopulmonary bypass in the incidence of postoperative delirium.Methods:Three hundred and fifty-seven adult patients who underwent normothermic coronary artery bypass grafting (CABG) surgery were included in this retrospective study. The nadir indexed DO2 (DO2i) value on bypass, the total time under the critical DO2i level and the area under the curve (AUC) for critical DO2i were determined. Delirium was identified by the postoperative administration of haloperidol.Results:The mean nadir DO2i significantly differed, comparing the group of patients with postoperative delirium to the group without. Multivariate analysis only identified age, pre-existing cognitive impairment, preoperative kidney dysfunction and cross-clamp time as independent risk factors for delirium. The results also indicated that patients of older age were more sensitive to a declined DO2i.Conclusion:A low DO2i during cardiopulmonary bypass is significantly associated with the incidence of postoperative delirium in CABG patients. However, the role of DO2 as an independent predictor of delirium could not be proven.

Processed electroencephalogram and evoked potential techniques for amelioration of postoperative delirium and cognitive dysfunction following non-cardiac and non-neurosurgical procedures in adults.

Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) may complicate a patient's postoperative recovery in several ways. Monitoring of processed electroencephalogram (EEG) or evoked potential (EP) indices may prevent or minimize POD and POCD, probably through optimization of anaesthetic doses. To assess whether the use of processed EEG or auditory evoked potential (AEP) indices (bispectral index (BIS), narcotrend index, cerebral state index, state entropy and response entropy, patient state index, index of consciousness, A-line autoregressive index, and auditory evoked potentials (AEP index)) as guides to anaesthetic delivery can reduce the risk of POD and POCD in non-cardiac surgical or non-neurosurgical adult patients undergoing general anaesthesia compared with standard practice where only clinical signs are used. We searched CENTRAL, MEDLINE, Embase and clinical trial registry databases up to 28 March 2017. We updated this search in February 2018, but these results have not been incorporated in the review. We included randomized or quasi-randomized controlled trials comparing any method of processed EEG or evoked potential techniques (entropy, BIS, AEP etc.) against a control group where clinical signs were used to guide doses of anaesthetics in adults aged 18 years or over undergoing general anaesthesia for non-cardiac or non-neurosurgical elective operations. We used the standard methodological procedures expected by Cochrane. Our primary outcomes were: occurrence of POD; and occurrence of POCD. Secondary outcomes included: all-cause mortality; any postoperative complications; and postoperative length of stay. We used GRADE to assess the quality of evidence for each outcome. We included six randomized controlled trials (RCTs) with 2929 participants comparing processed EEG or EP indices-guided anaesthesia with clinical signs-guided anaesthesia. There are five ongoing studies and one study awaiting classification.Anaesthesia administration guided by the indices from a processed EEG (bispectral index) probably reduces the risk of POD within seven days after surgery with risk ratio (RR) of 0.71 (95% CI 0.59 to 0.85; number needed to treat for an additional beneficial outcome (NNTB) of 17, 95% CI 11 to 34; 2197 participants; 3 RCTs; moderate quality of evidence). Three trials also showed the lower rate of POCD at 12 weeks after surgery (RR 0.71, 95% CI 0.53 to 0.96; NNTB 38, 95% CI 21 to 289; 2051 participants; moderate-quality evidence), but it is uncertain whether processed EEG indices reduce POCD at one week (RR 0.84, 95% CI 0.69 to 1.02; 3 trials; 1989 participants; moderate-quality evidence), and at 52 weeks (RR 0.30, 95% CI 0.05 to 1.80; 1 trial; 59 participants; very low quality of evidence). There may be little or no effect on all-cause mortality (RR 1.01, 95% CI 0.62 to 1.64; 1 trial; 1155 participants; low-quality evidence). One trial suggested a lower risk of any postoperative complications with processed EEG (RR 0.51, 95% CI 0.37 to 0.71; 902 participants, moderate-quality evidence). There may be little or no effect on reduced postoperative length of stay (mean difference -0.2 days, 95% CI -2.02 to 1.62; 1155 participants; low-quality evidence). There is moderate-quality evidence that optimized anaesthesia guided by processed EEG indices could reduce the risk of postoperative delirium in patients aged 60 years or over undergoing non-cardiac surgical and non-neurosurgical procedures. We found moderate-quality evidence that postoperative cognitive dysfunction at three months could be reduced in these patients. The effect on POCD at one week and over one year after surgery is uncertain. There are no data available for patients under 60 years. Further blinded randomized controlled trials are needed to elucidate strategies for the amelioration of postoperative delirium and postoperative cognitive dysfunction, and their consequences such as dementia (including Alzheimer's disease (AD)) in both non-elderly (below 60 years) and elderly (60 years or over) adult patients. The one study awaiting classification and five ongoing studies may alter the conclusions of the review once assessed.

Annals for Educators - 3 April 2018.

Annals for Educators - 3 April 2018.

Postoperative delirium in total knee and hip arthroplasty patients: a study of perioperative modifiable risk factors

BackgroundPostoperative delirium continues to pose major clinical difficulties. While unmodifiable factors (e.g. age and comorbidity burden) are commonly studied risk factors for delirium, the role of modifiable factors, such as anaesthesia type and commonly used perioperative medications, remains understudied. This study aims to evaluate the role of modifiable factors for delirium after hip and knee arthroplasties. MethodsWe performed a retrospective study of 41 766 patients who underwent hip or knee arthroplasties between 2005 and 2014 at a single institution. Data were collected as part of routine patient care. Multivariable logistic regression models assessed associations between anaesthesia type and commonly used perioperative medications (opioids, benzodiazepines, and ketamine) and postoperative delirium. Odds ratios (OR) and 95% confidence intervals (CI) are reported. Various sensitivity analyses are also considered, including multiple imputation methods to address missing data. ResultsPostoperative delirium occurred in 2.21% (n=922) of all patients. While patients who received neuraxial anaesthesia were at lower risk for postoperative delirium (compared with general anaesthesia; epidural OR 0.59 CI 0.38–0.93; spinal OR 0.55 CI 0.37–0.83; combined spinal/epidural OR 0.56 CI 0.40–0.80), those given intraoperative ketamine (OR 1.27 CI 1.01–1.59), opioids (OR 1.25 CI 1.09–1.44), postoperative benzodiazepines (OR 2.47 CI 2.04–2.97), and ketamine infusion (OR 10.59 CI 5.26–19.91) were at a higher risk. ConclusionsIn this cohort of hip and knee arthroplasty patients, anaesthesia type and perioperative medications were associated with increased odds for postoperative delirium. Our results support the notion that modifiable risk factors may exacerbate or attenuate risk for postoperative delirium.

Risk Factors for Postoperative Delirium After Deep Brain Stimulation Surgery for Parkinson Disease

The aim of this study was to investigate the incidence of and risk factors for postoperative delirium (POD) after deep brain stimulation (DBS) surgery in patients with Parkinson disease. We analyzed the preoperative T1-weighted magnetic resonance imaging data of 71 patients with Parkinson disease who underwent DBS surgery. Multiple regression analysis was performed with age, l-dopa equivalent daily dose, laterality of the surgery, target regions, number of electrode trajectories tried, gray matter volume, and white matter (WM) volume as explanatory variables and the duration (number of days) of POD as the response variable. In addition, regional brain atrophy associated with POD was investigated by means of voxel-based morphometry. Excluding patients with outliers, 61 patients were included in the analyses. POD had occurred in 26 of the 61 patients (42.6%). Age and total WM volume were shown by multiple regression analysis to correlate significantly with the duration of POD (P < 0.05 and < 0.01, respectively). WM was significantly reduced in the temporal stem, and the reduction in volume correlated significantly with the duration of POD (P < 0.001). Gray matter atrophy was not associated with POD. We found that age and WM atrophy in the temporal stem are factors predictive of POD after DBS surgery. In aged patients with temporal stem atrophy, surgical procedures and postoperative management should be carefully explored to reduce the risk of postoperative delirium.