High Risk For Postoperative Delirium Research Articles

Association between increased systemic immune-inflammation index and postoperative delirium in older intertrochanteric fracture patients

Background and purposeThe systemic immune-inflammation index (SII), a novel inflammation index derived from the counts of circulating platelets, neutrophils and lymphocytes, has been studied in the treatment of acute cancer and ischemic stroke (AIS). However, the clinical value of the SII in postoperative delirium patients has not been further investigated. The purpose of our research was to study the incidence and preoperative risk factors for postoperative delirium (POD) and verify whether the SII could serve as a potential marker for POD in older intertrochanteric fracture patients. Finally, we created a novel nomogram for predicting POD in older patients with intertrochanteric fractures.MethodsWe enrolled elderly patients with intertrochanteric fractures who underwent proximal femoral nail antirotation (PFNA) between February 2021 and April 2023. Univariate and multivariate logistic analyses were subsequently performed to confirm the risk factors and construct a nomogram model.Calibration curve and clinical decision curve analysis (DCA) were used to assess the model’s fitting performance. The performance of the nomogram was evaluated for discrimination, calibration, and clinical utility.ResultsA total of 293 patients were eligible for inclusion in the study, 25.6% (75/293) of whom had POD. The POD patients had higher SII values than the non-POD patients. The SII was strongly correlated with POD in older intertrochanteric fracture patients, and the optimal cutoff value was 752.6 × 109. Multivariate analysis revealed that age, diabetes, total albumin, SII > 752.6 × 109 and a CRP > 20.25 mg/L were independent risk factors for POD patients. By incorporating these 5 factors, the model achieved a concordance index of 0.745 (95% CI, 0.683–0.808) and had a well-fitted calibration curve and good clinical application value.ConclusionThe SII is a simple and valuable biomarker for POD, and the new nomogram model can be used to accurately predict the occurrence of POD. They can be utilized in clinical practice to identify those at high risk of POD in older intertrochanteric fracture patients.

Resting-state prefrontal EEG biomarker in correlation with postoperative delirium in elderly patients.

Postoperative delirium (POD) is associated with adverse outcomes in elderly patients after surgery. Electroencephalography (EEG) can be used to develop a potential biomarker for degenerative cerebral dysfunctions, including mild cognitive impairment and dementia. This study aimed to explore the relationship between preoperative EEG and POD. We included 257 patients aged >70 years who underwent spinal surgery. We measured the median dominant frequency (MDF), which is a resting-state EEG biomarker involving intrinsic alpha oscillations that reflect an idle cortical state, from the prefrontal regions. Additionally, the mini-mental state examination and Montreal cognitive assessment (MoCA) were performed before surgery as well as 5 days after surgery. For long-term cognitive function follow up, the telephone interview for cognitive status™ (TICS) was performed 1 month and 1 year after surgery. Fifty-two (20.2%) patients were diagnosed with POD. A multivariable logistic regression analysis that included age, MoCA score, Charlson comorbidity index score, Mini Nutritional Assessment, and the MDF as variables revealed that the MDF had a significant odds ratio of 0.48 (95% confidence interval 0.27-0.85). Among the patients with POD, the postoperative neurocognitive disorders could last up to 1 year. Low MDF on preoperative EEG was associated with POD in elderly patients undergoing surgery. EEG could be a novel potential tool for identifying patients at a high risk of POD.

Metabolic syndrome and the risk of postoperative delirium and postoperative cognitive dysfunction: a multi-centre cohort study

BackgroundMetabolic syndrome and its components are risk factors for cognitive impairment, but their contribution to perioperative neurocognitive disorders is unknown. We examined their associations with the risk of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) in older patients. MethodsIn 765 male and female participants aged ≥65 years, we measured preoperative metabolic parameters and screened for POD for 7 days or until discharge. POCD was defined through comparison of cognitive change on six neuropsychological tests with non-surgical controls. Multiple logistic regression analyses examined the association of metabolic parameters with risk of POD and POCD with adjustment for age, sex, and surgery type. ResultsA total of 149 patients (19.5% of 765) developed POD and 53 (10.1% of 520 attendees) had POCD at 3 months. Patients with metabolic syndrome were at 1.85-fold higher risk of POD (95% confidence interval [CI] 1.26–2.70). Each 1 mM higher high-density lipoprotein cholesterol (HDL-C) was associated with a 0.47-fold lower POD risk (95% CI 0.30–0.74). Each 1 kg m−2 higher body mass index (BMI) was associated with a 1.09-fold higher POCD risk (95% CI 1.02– 1.16). ConclusionsOlder surgical patients with metabolic syndrome were at increased risk of POD. Only reduced HDL-C was significantly associated with POD. For POCD, a higher preoperative BMI was identified as a risk factor. These findings add to mounting evidence of a distinct epidemiology of POD and POCD. Screening programmes taking advantage of HDL-C and BMI measurements and of metabolic interventions in reducing perioperative neurocognitive disorders should be evaluated. Clinical trial registrationNCT02265263.

Delirium in older patients given propofol or sevoflurane anaesthesia for major cancer surgery: a multicentre randomised trial

BackgroundDelirium is a common and disturbing postoperative complication that might be ameliorated by propofol-based anaesthesia. We therefore tested the primary hypothesis that there is less delirium after propofol-based than after sevoflurane-based anaesthesia within 7 days of major cancer surgery. MethodsThis multicentre randomised trial was conducted in 14 tertiary care hospitals in China. Patients aged 65–90 yr undergoing major cancer surgery were randomised to either propofol-based anaesthesia or to sevoflurane-based anaesthesia. The primary endpoint was the incidence of delirium within 7 postoperative days. ResultsA total of 1228 subjects were enrolled and randomised, with 1195 subjects included in the modified intention-to-treat analysis (mean age 71 yr; 422 [35%] women); one subject died before delirium assessment. Delirium occurred in 8.4% (50/597) of subjects given propofol-based anaesthesia vs 12.4% (74/597) of subjects given sevoflurane-based anaesthesia (relative risk 0.68 [95% confidence interval {CI}: 0.48–0.95]; P=0.023; adjusted relative risk 0.59 [95% CI: 0.39–0.90]; P=0.014). Delirium reduction mainly occurred on the first day after surgery, with a prevalence of 5.4% (32/597) with propofol anaesthesia vs 10.7% (64/597) with sevoflurane anaesthesia (relative risk 0.50 [95% CI: 0.33–0.75]; P=0.001). Secondary endpoints, including ICU admission, postoperative duration of hospitalisation, major complications within 30 days, cognitive function at 30 days and 3 yr, and safety outcomes, did not differ significantly between groups. ConclusionsDelirium was a third less common after propofol than sevoflurane anaesthesia in older patients having major cancer surgery. Clinicians might therefore reasonably select propofol-based anaesthesia in patients at high risk of postoperative delirium. Clinical trial registrationChinese Clinical Trial Registry (ChiCTR-IPR-15006209) and ClinicalTrials.gov (NCT02662257).

Incidence of postoperative delirium in older adults undergoing surgical procedures: A systematic literature review and meta-analysis.

With the increase in life expectancy around the globe, the incidence of postoperative delirium (POD) among older people (≥65 years) is growing. Previous studies showed a wide variation in the incidence of POD, from 4% to 53%, with a lack of specific evidence about the incidence of POD by specific surgery type among older people. The aim of this systematic review and meta-analysis was to determine the incidence of POD by surgery type within populations 65 years and over. Databases including PubMed, Cochrane library, Embase, and CINAHL were searched until October 2020. Due to the relatively higher number of meta-analyses undertaken in this area of research, a streamlined systematic meta-analysis was proposed. A total of 28 meta-analyses (comprising 284 individual studies) were reviewed. Data from relevant individual studies (n = 90) were extracted and included in the current study. Studies were grouped into eight surgery types and the incidence of POD for orthopedic, vascular, spinal, cardiac, colorectal, abdominal, urologic, and mixed surgeries was 20%, 14%, 13%, 32%, 14%, 30%, 10%, and 26%, respectively. POD detection instruments were different across the studies, with Confusion Assessment Method (CAM & CAM-ICU) being the most frequently adopted. This study showed that POD incidence in older people undergoing surgery varied widely across surgery type. The more complex surgeries like cardiac and abdominal surgeries were associated with a higher risk of POD. This highlights the need to include the level of surgery complexity as a risk factor in preoperative assessments.

681 Postoperative Muscle Relaxant Use Associated With Increased Risk of Delirium Following Lumbar Spinal Fusion

INTRODUCTION: Muscle relaxants including cyclobenzaprine and baclofen are frequently utilized in pain management following spine surgery as part of enhanced recovery after surgery (ERAS) protocols. These medications are associated with anticholinergic and central nervous system side effects and are used with caution in outpatient treatment for those at high-risk of delirium, especially the elderly. Literature investigating their association with delirium in the postoperative setting has not been described. METHODS: Patients over age 65 undergoing elective posterior lumbar fusion between 2017 and 2021 at the senior author’s institution were retrospectively reviewed. Variables collected included patient demographics as well as whether subjects received postoperative administration of baclofen and/or cyclobenzaprine on postoperative day 1 as part of a multimodal analgesia regimen. Doubly-robust inverse probability weighting (IPW) with cox-regression was used to evaluate the incidence of postoperative delirium between groups. RESULTS: Five-hundred and thirty-one patients were included in the analysis. Incidence of delirium in those who received postoperative muscle relaxants was 17.6% (44/250) compared to 11.4% (32/281) in the control group who did not (p = 0.001). Doubly-robust IPW analysis found patients who received muscle relaxants were at a 2.07 (95% CI: 1.18-3.63) times increased risk of delirium compared to controls (p = 0.015). Postoperative time to delirium onset was similar between groups (3.0 vs 3.1 days; p = 0.916) while the average duration of delirium was significantly longer in those who received postoperative muscle relaxants (2.5 vs 1.6 days; p = 0.008). CONCLUSIONS: Postoperative muscle relaxant use was associated with a higher risk of delirium in elderly adults following lumbar spinal fusion. Although muscle relaxants may assist with postoperative pain control as part of ERAS protocols while minimizing opioid administration, their side effect profile should be considered in patients at high risk of postoperative delirium.

Preoperative frailty vs. cognitive impairment: Which one matters most for postoperative delirium among older adults with cancer?

IntroductionLimited data are available to explore the association between preoperative frailty and cognitive impairment with postoperative delirium among older adults with cancer.We explored this association in a single Comprehensive Cancer Center where postoperative delirium and frailty are assessed in routine care using the Confusion Assessment Method (CAM) and Memorial Sloan Kettering Frailty Index (MSK-FI), respectively. Materials and MethodsRetrospective study on patients with cancer, aged 65+, who underwent surgery from April 2018 to March 2019 with hospital stay ≥1 day. We used logistic regression with postoperative delirium as the outcome, primary predictor MSK-FI, adjusted for age, operative time, and preoperative albumin. As the MSK-FI includes a component related to cognitive impairment, we additionally evaluated the impact of this component, separately from the rest of the score, on the association between frailty and postoperative delirium. ResultsAmong 1,257 patients with available MSK-FI and CAM measures, 47 patients (3.7%) had postoperative delirium. Increased frailty was associated with increased risk of postoperative delirium (odds ratio [OR] 1.51; 95% confidence interval [CI] 1.26, 1.81; p < 0.001). However, this was largely related to the effect of cognitive impairment (OR 15.29; 95% CI 7.18; 32.56; p < 0.001). In patients with cognitive impairment, the association between frailty and postoperative delirium was not significant (OR 0.97; 95% CI 0.65, 1.44; p-value = 0.9), as having cognitive impairment put patients at high risk for postoperative delirium even without taking into account the other components of the MSK-FI. While the association between frailty and postoperative delirium in patients with intact cognitive function was statistically significant (OR 1.58; 95% CI 1.27, 1.96; p < 0.001), it was not clinically meaningful, particularly considering the low risk of delirium among patients with intact cognitive function (e.g., 1.3% vs 3.2% for MSK-FI 1 vs 3). DiscussionCognitive function should be a greater focus than frailty, as measured by the MSK-FI, in preoperative assessment for the prediction of postoperative delirium.

Postoperative Use of the Muscle Relaxants Baclofen and/or Cyclobenzaprine Associated With an Increased Risk of Delirium Following Lumbar Fusion.

Retrospective, single-center, cohort study. Investigate whether the incidence of postoperative delirium in older adults undergoing spinal fusion surgery is associated with postoperative muscle relaxant administration. Baclofen and cyclobenzaprine are muscle relaxants frequently used for pain management following spine surgery. Muscle relaxants are known to cause central nervous system side effects in the outpatient setting and are relatively contraindicated in individuals at high risk for delirium. However, there are no known studies investigating their side effects in the postoperative setting. Patients over 65 years of age who underwent elective posterior lumbar fusion for degenerative spine disease were stratified into two treatment groups based on whether postoperative muscle relaxants were administered on postoperative day one as part of a multimodal analgesia regimen. Doubly robust inverse probability weighting with cox regression for time-dependent covariates was used to examine the association between postoperative muscle relaxant use and the risk of delirium while controlling for variation in baseline characteristics. The incidence of delirium was 17.6% in the 250 patients who received postoperative muscle relaxants compared with 7.9% in the 280 patients who did not receive muscle relaxants ( P=0.001 ). Multivariate analysis to control for variation in baseline characteristics between treatment groups found that patients who received muscle relaxants had a 2.00 (95% CI: 1.14-3.49) times higher risk of delirium compared with controls ( P=0.015 ). Postoperative use of muscle relaxants as part of a multimodal analgesia regimen was associated with an increased risk of delirium in older adults after lumber fusion surgery. Although muscle relaxants may be beneficial in select patients, they should be used with caution in individuals at high risk for postoperative delirium.

Implication of age-related changes on anesthesia management.

Elderly patients have a high risk of perioperative morbidity and mortality. Pluri-morbidities, polypharmacy, and functional dependence may have a great impact on intraoperative management and request specific cautions. In addition to surgical stress, several perioperative noxious stimuli such as fasting, blood loss, postoperative pain, nausea and vomiting, drug adverse reactions, and immobility may trigger a derangement leading to perioperative complications. Older patients have a high risk of major hemodynamic derangement due to aging of the cardiovascular system and associated comorbidities. The hemodynamic monitoring as well as fluid therapy should be the most accurate as possible. Aging is accompanied by decreased renal function, which is related to a reduction in renal blood flow, renal mass, and the number and size of functioning nephrons. Drugs eliminated predominantly by the renal route need dosage adjustments based on residual renal function. Liver mass, hepatic blood flow, and intrinsic metabolic activity are decreased in the elderly, and all drugs metabolized by the liver have a variable half-life, thus requiring dose reduction. Decreased neural plasticity contributes to a high risk for postoperative delirium. Monitoring of anesthesia depth should be mandatory to avoid overdosage of hypnotic drugs. Prevention of postoperative pulmonary complications requires both protective ventilation strategies and adequate recovery of neuromuscular function at the end of surgery. Avoidance of hypothermia cannot be missed. The aim of this review is to describe comprehensive strategies for intraoperative management plans tailored to meet the unique needs of elderly surgical patients, thus improving outcomes in this vulnerable population.

Two-stage prediction model for postoperative delirium in patients in the intensive care unit after cardiac surgery.

Postoperative delirium is a common severe complication in patients in the intensive care unit after cardiac surgery. We developed a two-stage prediction model and quantified the risk of developing postoperative delirium to assist in early prevention before and after surgery. We conducted a prospective cohort study and consecutively recruited adult patients after cardiac surgery. The Confusion Assessment Method for patients in the intensive care unit was used to diagnose delirium 5 days postoperatively. The stage I model was constructed using patient demographics, health conditions and laboratory results obtained preoperatively, whereas the stage II model was built on both pre- and postoperative predictors. The model was validated internally using the bootstrap method and externally using data from an external cohort. The two-stage model was developed with 654 patients and was externally validated with 214 patients undergoing cardiac surgery. The stage I model contained 6 predictors, whereas the stage II model included 10 predictors. The stage I model had an area under the receiver operating characteristic curve of 0.76 (95% confidence interval: 0.68-0.81), and the stage II model's area under the receiver operating characteristic curve increased to 0.85 [95% confidence interval (CI): 0.81-0.89]. The external validation resulted in an area under the curve of 0.76 (95% CI: 0.67-0.86) for the stage I model and 0.78 (95% CI: 0.69-0.86) for the stage II model. The two-stage model assisted medical staff in identifying patients at high risk for postoperative delirium before and 24 h after cardiac surgery. This model showed good discriminative power and predictive accuracy and can be easily accessed in clinical settings. The study was registered with the US National Institutes of Health ClinicalTrials.gov (NCT03704324; registered 11 October 2018).

Preoperative anxiety as an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation.

Anxiety is common in older patients suffering from lumbar disc herniation. Postoperative delirium is related to poor prognosis. But the relationship between preoperative anxiety and postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation is not clear. The study aimed to investigate if preoperative anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation. The medical records of 1290 patients undergoing elective surgery for lumbar disc herniation at a single institution from 2016 through 2021 were reviewed. Of 863 eligible patients, 225 (26.1%) patients had been diagnosed with anxiety by a board-certified psychiatrist and constituted the Anxiety group; the remaining 638 patients constituted the no-anxiety group. The demographics, baseline, operative variable and postoperative complications were collected and compared between the two groups. The primary outcome of this study was the incidence of delirium, according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition, during a hospital stay after surgery for lumbar disc herniation. The relationship between anxiety and postoperative delirium was determined through multivariate logistic regression analysis. The demographics and comorbidity were similar between the two groups, except for age, sex, alcohol use and cerebrovascular disease. The operative variables were different between the two groups. The incidence of postoperative complications other than postoperative delirium was also similar between the two groups. In total, 86 patients (9.97%) had an episode of postoperative delirium, with anxiety group patients experiencing approximately a twofold higher rate (15.6% vs 7.99%). In a multivariate logistic regression analysis, anxiety was an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation (OR 2.228, 95% CI 1.494-3.416, p = 0.009). This study suggests that anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation. Preoperative anxiety assessment can help to identify older patients at high risk of postoperative delirium and facilitate perioperative management of older patients undergoing elective surgery for lumbar disc herniation.

Dose-dependent relationship between intra-procedural hypoxaemia or hypocapnia and postoperative delirium in older patients

BackgroundPrevious studies indicated an association between impaired cerebral perfusion and post-procedural neurological disorders. We investigated whether intra-procedural hypoxaemia or hypocapnia are associated with delirium after surgery. MethodsInpatients ≥60 yr of age undergoing anaesthesia for surgical or interventional procedures between 2009 and 2020 at an academic healthcare network in the USA (Massachusetts) were included in this hospital registry study. The primary exposure was intra-procedural hypoxaemia, defined as peripheral oxygen saturation <90% for >2 cohering min. The co-primary exposure was hypocapnia during general anaesthesia, defined as end-tidal carbon dioxide pressure ≤25 mm Hg for >5 cohering min. The primary outcome was delirium within 7 days after surgery. ResultsOf 71 717 included patients, 1702 (2.4%) developed postoperative delirium, and hypoxaemia was detected in 2532 (3.5%). Of 42 894 patients undergoing general anaesthesia, 532 (1.2%) experienced hypocapnia. The occurrence of either hypoxaemia (adjusted odds ratio [ORadj]=1.71; 95% confidence interval [CI], 1.40–2.07; P<0.001) or hypocapnia (ORadj=1.77; 95% CI, 1.30–2.41; P<0.001) was associated with a higher risk of delirium within 7 days. Both associations were dependent on the magnitude, and increased with event duration (ORadj=1.03; 95% CI, 1.02–1.04; P<0.001 and ORadj=1.01; 95% CI, 1.00–1.01; P=0.005, for each minute increase in the longest continuous episode, respectively). There was no association between occurrence of hypercapnia and postoperative delirium (ORadj=1.24; 95% CI, 0.90–1.71; P=0.181). ConclusionsIntra-procedural hypoxaemia and hypocapnia were dose-dependently associated with a higher risk of postoperative delirium. These findings support maintaining normal gas exchange to avoid postoperative neurological disorders.

Perioperative Hemodynamic Optimization in Patients at Risk for Delirium - A Randomized-Controlled Trial.

BackgroundPost-operative delirium is common in elderly patients and associated with increased morbidity and mortality. We evaluated in this pilot study whether a perioperative goal-directed hemodynamic optimization algorithm improves cerebral oxygenation and can reduce the incidence of delirium.Materials and MethodsPatients older than 70 years with high risk for post-operative delirium undergoing elective non-cardiac surgery were randomized to an intervention or control group. Patients in the intervention group received a perioperative hemodynamic optimization protocol based on uncalibrated pulse-contour analysis. Patients in the control group were managed according to usual standard of care. Incidence of delirium until day seven was assessed with confusion assessment method (CAM) and chart review. Cerebral oxygenation was measured with near-infrared spectroscopy.ResultsDelirium was present in 13 of 85 (15%) patients in the intervention group and 18 of 87 (21%) in the control group [risk difference −5.4%; 95% confidence interval, −16.8 to 6.1%; P = 0.47]. Intervention did not influence length of stay in hospital or in-hospital mortality. Amounts of fluids and vasopressors applied, mean arterial pressure, cardiac index, and near-infrared spectroscopy values were comparable between groups.ConclusionThe hemodynamic algorithm applied in high-risk non-cardiac surgery patients did not change hemodynamic interventions, did not improve patient hemodynamics, and failed to increase cerebral oxygenation. An effect on the incidence of post-operative delirium could not be observed.Clinical Trial Registration[Clinicaltrials.gov], identifier [NCT01827501].

The association between Monocyte-to-Lymphocyte ratio and postoperative delirium in ICU patients in cardiac surgery.

ObjectiveTo analyze the relationship between monocyte‐to‐lymphocyte ratio (MLR) and postoperative delirium (POD).MethodsThis cohort study was conducted in the Medical Information Mart for Intensive Care‐III (MIMIC‐III) version 1.4 database. MLR was measured according to the complete blood count. ICD‐9 was used to measure postoperative delirium. Multivariable logistic regression was utilized to examine the relationship between MLR and POD.ResultsThree thousand eight hundred sixty‐eight patients who had received cardiac surgery were retrospectively enrolled, including 2171 males and 1697 females, with a mean age of 63.9 ± 16.2 years. The univariate analysis suggested that high MLR (as a continuous variable) as associated with a 21% higher risk of POD (O R: 1.12, 95% CI, 1.02, 1.43, p = 0.0259), After adjustments for other confounding factors, gender, age, race, temperature, SBP, DBP, MAP, respiratory rate, SOFA, peripheral vascular disease, AG, psychoses, drug, and alcohol addiction, the results showed that high MLR (as a continuous variable) independently served as a risk factor for POD (OR: 1.21; 95% CI: 1.01–1.44; p = 0.0378). MLR was assessed as quintile and tertiles, high MLR was an independent risk factor for POD. In the subgroup analysis, there were no differences in MLR for patients with POD in pre‐specified subgroups.ConclusionsMonocyte‐to‐lymphocyte ratio was a risk factor for POD. More research is necessary to thoroughly examine the function of MLR in POD.

Elevated Substance P Is a Risk Factor for Postoperative Delirium in Patients with Hip Fracture.

Objective Hip fractures are quite common worldwide, especially among the elderly, and are associated with a high incidence of postoperative delirium, which worsens functional results and increases death. The causes of postoperative delirium in patients with hip fractures are unknown, and a separate pathobiology has been hypothesized. Substance P is a neuropeptide that has been linked to a number of immune-inflammatory and neurological conditions. The purpose of this study was to see if serum substance P levels could predict postoperative delirium in a group of hip fracture patients. Methods A total of 148 hip fracture patients were enrolled in the study, all of whom had no substantial pre-existing medical or cognitive issues. Demographic and regular laboratory data were gathered as a starting point. ELISA was used to examine substance P levels before and after surgery (after 1 day). Patients were then divided into two groups: “postoperative delirium” and “no postoperative delirium.” Intergroup comparisons, study of delirium prevalence rates in postoperative serum substance P quartile categories, and binary logistic regression for postoperative delirium category as outcome were all done. Results Except for serum low-density lipoprotein (LDL) levels, there were no statistically significant variations in preoperative substance P levels or other baseline characteristics between the two groups. The “postoperative delirium” group had significantly higher postoperative substance P levels than the “no postoperative delirium” group (46.36.1 versus 31.94.7 pg/ml). There was a significant difference in postoperative delirium rates between the quartile categories of postoperative substance P, with the fourth quartile having the highest rate. Regression analysis revealed that postoperative substance P levels were related with a significantly increased OR (1.265, CI: 1.172-1.283) of postoperative delirium. Conclusion In the current sample of hip fracture patients, a higher postoperative serum substance P level was linked to a higher risk of postoperative delirium. Further research into the utility of early postoperative serum substance P as a delirium indicator in hip fracture patients is needed.

Nocturnal dexmedetomidine for prevention of delirium in critically ill surgical patients: a randomized control trial protocol

Background: Nocturnal or postoperative dexmedetomidine has been shown to reduce the incidence of delirium in critically ill surgical patients without an increase in any complications. However, it is not clear whether dexmedetomidine has preventive effect against delirium in the patients with high risk of postoperative delirium (POD) since no previous studies have clearly emphasized high-risk surgical patients. Method: In this single-center, double-blind, randomized controlled trial, we randomize 114 high risk POD patients defined by developed predictive scores and admitted to surgical intensive care units (SICUs) into 2 groups: nocturnal dexmedetomidine (9 pm – 6 am) and placebo. The outcomes were incidence of POD, delirium-free days, secondary delirium-related complications and concerned complications including hypotension and bradycardia. Other treatments apart from intervention are standardized. Intention to treat analysis is used to analyze all data. Hypothesis: We hypothesize that nocturnal dexmedetomidine giving to high-risk POD patients admitted to SICUs postoperatively would (1) reduce incidence of POD (2) improve delirium-free days (3) reduce secondary delirium-related complications (4) show no difference in hypotension and bradycardia between groups. Ethics and dissemination: The trial receives ethic approval from Siriraj Institutional Review Board. We plan to disseminate the results in peer-reviewed critical care medicine or anesthesiology-related journals, conferences nationally and internationally. Trial registration: TCTR20210217001

Gender Differences and Postoperative Delirium in Adult Patients Undergoing Cardiac Valve Surgery.

Background: Postoperative delirium (POD) is common in patients following cardiac surgery. According to studies on non-cardiac surgery, males suffered from higher incidence of POD. However, there is no report about effect of gender differences on POD occurrence in cardiac surgery patients. The aim of this study was to investigate the effect of gender differences on POD occurrence in adult patients after cardiac valve surgery.Methods: This is a retrospective case-control study. We recorded the clinical data in adult patients who underwent elective cardiac valve surgery from May 2019 to October 2020. POD was assessed by the Confusion Assessment Method for Intensive Care Unit. Univariate analysis was used to screen the potential risk factors. Collinearity analysis was conducted to detect overlapping predictor variables on the outcomes. A multivariate logistic regression with odds ratio (OR) and 95% confidence interval (CI) was used to identify the independent risk factors. The Hosmer-Lemeshow test was performed to show the good calibration of the logistic regression model.Results: In total, we recorded the perioperative data in 431 adult patients, including 212 males and 219 females. Sixty patients suffered from POD, including 39 males and 21 females. Twenty-one perioperative variables were selected, and 11 were screened by univariate analysis. We did not detect the severe collinearity among the 11 variables. Male gender was identified as a significant risk factor in POD occurrence in patients undergoing cardiac surgery (Adjusted OR: 2.213, 95% CI: 1.049–4.670, P = 0.037). The Hosmer-Lemeshow test demonstrated good calibration of the logistic regression model (χ2 = 7.238, P = 0.511). Besides, compared with females, the relationship of male and delirium subtypes was as follows: (1) hyperactive: adjusted OR: 3.384, 95% CI: 1.335–8.580, P = 0.010; (2) hypoactive: adjusted OR: 0.509, 95% CI: 0.147–1.766, P = 0.287. A Stratification analysis by age demonstrated that the males showed higher POD incidence in patients aged younger than 60 years (adjusted OR: 4.384, 95% CI: 1.318–14.586, P = 0.016).Conclusions: Male gender is an important risk factor in POD occurrence in patients following cardiac surgery. Furthermore, the incidence of hyperactive delirium is higher in males. Besides, the male patients aged younger than 60 years are at high risk of POD. We should pay more attention to the male patients to prevent their POD occurrence.

Red Blood Cell Transfusion and Postoperative Delirium in Hip Fracture Surgery Patients: A Retrospective Observational Cohort Study.

Background Patients having hip fracture surgery are at high risk for postoperative delirium. Red blood cell (RBC) transfusion may increase postoperative delirium risk by causing neuroinflammation. We hypothesized that RBC transfusion would be associated with postoperative delirium in patients having hip fracture surgery. Methods An observational cohort study was performed using the United States National Surgical Quality Improvement Program (NSQIP) participant use files for hip fracture from 2016 to 2018. Propensity score analysis and inverse probability of treatment weighting (IPTW) were used to reduce bias from confounding. An IPTW adjusted odds ratio for developing postoperative delirium was calculated for patients who received RBC transfusion during surgery or in the 72 hours after. Results There were 20,838 patients who had eligible current procedural terminology (CPT) codes for primary hip fracture surgery and complete study data. After employing strict exclusions to balance covariates and reduce bias, 3,715 patients remained in the IPTW cohort. Of these, 626 patients (16.9%) received RBC transfusion and 665 patients (17.9%) developed postoperative delirium. IPTW adjustment led to good covariate balance between patients who received RBC transfusion and those who did not. Patients who received RBC transfusion had significantly higher odds of postoperative delirium, IPTW adjusted odds ratio = 1.21, 95% CI = 1.03 to 1.43, and P = 0.02. Discharge location also differed significantly between patients who received RBC transfusion and those who did not (P < 0.001) with in-hospital mortality or referral to hospice occurring in 1.6% of patients who received RBC transfusion and 1.3% of patients who were not transfused. Conclusion RBC transfusion is associated with increased odds of postoperative delirium after hip fracture surgery and may be associated with worse clinical outcome.

Is it time to Assess Neurological Status Before Surgery to Improve Postoperative Outcomes?

Is it time to Assess Neurological Status Before Surgery to Improve Postoperative Outcomes?

Higher neutrophil-to-lymphocyte ratio, mean platelet volume, and platelet distribution width are associated with postoperative delirium in patients undergoing esophagectomy: a retrospective observational study.

We investigated whether preoperative inflammatory markers, i.e., the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), mean platelet volume (MPV), and platelet distribution width (PDW) can predict the development of postoperative delirium (POD) after esophagectomy. This single-center, retrospective, observational study included 110 patients who underwent an esophagectomy. We assigned the patients with the Intensive Care Delirium Screening Checklist score ≥ 4 to the POD group. We performed multivariable logistic regression analyses to determine whether the NLR, PLR, MPV, and PDW can be used to predict the development of POD. The POD group had 20 patients; the non-POD group included the other 90 patients. Although only the preoperative NLR in the POD group was significantly higher than in the non-POD group (3.20 [2.52-4.30] vs. 2.05 [1.45-3.02], p = 0.001), multivariable logistic regression analyses showed that the following three parameters were independent predictors of POD: preoperative NLR ≥ 2.45 (adjusted odds ratio [aOR]: 8.68, 95%CI 2.33-32.4, p = 0.001), MPV ≥ 10.4 (aOR: 3.93, 95%CI: 1.37-11.2, p = 0.011), and PDW ≥ 11.8 (aOR: 3.58, 95%CI: 1.22-10.5, p = 0.020). Our analysis results demonstrated that preoperative NLR ≥ 2.45, MPV ≥ 10.4, and PDW ≥ 11.8 were significantly associated with a higher risk of POD after adjustment for possible confounding factors. However, as the AUCs of the preoperative MPV and PDW for the prediction of the development of POD in univariable ROC analyses were low, large prospective studies are needed to confirm this result.