Delirium In Elderly Patients Research Articles

Prediction models for postoperative delirium in elderly patients with machine-learning algorithms and SHapley Additive exPlanations

Postoperative delirium (POD) is a common and severe complication in elderly patients with hip fractures. Identifying high-risk patients with POD can help improve the outcome of patients with hip fractures. We conducted a retrospective study on elderly patients (≥65 years of age) who underwent orthopedic surgery with hip fracture between January 2014 and August 2019. Conventional logistic regression and five machine-learning algorithms were used to construct prediction models of POD. A nomogram for POD prediction was built with the logistic regression method. The area under the receiver operating characteristic curve (AUC-ROC), accuracy, sensitivity, and precision were calculated to evaluate different models. Feature importance of individuals was interpreted using Shapley Additive Explanations (SHAP). About 797 patients were enrolled in the study, with the incidence of POD at 9.28% (74/797). The age, renal insufficiency, chronic obstructive pulmonary disease (COPD), use of antipsychotics, lactate dehydrogenase (LDH), and C-reactive protein are used to build a nomogram for POD with an AUC of 0.71. The AUCs of five machine-learning models are 0.81 (Random Forest), 0.80 (GBM), 0.68 (AdaBoost), 0.77 (XGBoost), and 0.70 (SVM). The sensitivities of the six models range from 68.8% (logistic regression and SVM) to 91.9% (Random Forest). The precisions of the six machine-learning models range from 18.3% (logistic regression) to 67.8% (SVM). Six prediction models of POD in patients with hip fractures were constructed using logistic regression and five machine-learning algorithms. The application of machine-learning algorithms could provide convenient POD risk stratification to benefit elderly hip fracture patients.

Association Between Preoperative Long-Term Poor Sleep Quality and Postoperative Delirium in Elderly Patients Undergoing Cardiac Surgery: A Multi-Center Observational Study.

Delirium is a common complication in elderly patients after cardiac surgery, and sleep disorders have been suggested as a potential risk factor. However, few studies have explored the link between long-term preoperative poor sleep quality and postoperative delirium (POD) in this population. This study aimed to investigate the association between preoperative sleep quality and POD in elderly cardiac surgery patients. The study enrolled 194 patients aged 60years or older who underwent cardiac surgery. The Pittsburgh Sleep Quality Index (PSQI) objectively assessed preoperative sleep quality, while the Confusion Assessment Method screened for POD. The measurable outcomes encompassed the identification of risk factors associated with POD, while the secondary outcomes focused on factors influencing levels of consciousness. The statistical analysis is logistic regression analysis. Patients with POD had a higher prevalence of preoperative sleep disorders and higher PSQI scores than those without delirium (12.9 ± 5.1 vs 7.8 ± 3.4, P = .007). Logistic regression analysis demonstrated that the number of months with high PSQI scores and age were significantly associated with POD. The predictive ability of the number of months with high PSQI scores for POD was .762 (95% CI: .671-.854). Multivariate linear regression analysis revealed that preoperative sleep disorder was a significant predictor of exacerbation of POD (P < .05). This study suggests that long-term poor preoperative sleep quality, as assessed by the PSQI, is associated with an increased risk of POD in elderly patients undergoing cardiac surgery.

Association of sleep quality on the night of operative day with postoperative delirium in elderly patients: A prospective cohort study.

Sleep disturbances in the peri-operative period have been associated with adverse outcomes, including postoperative delirium (POD). However, research on sleep quality during the immediate postoperative period is limited. This study aimed to investigate the association between sleep quality on the night of the operative day assessed using the Sleep Quality Numeric Rating Scale (SQ-NRS), and the incidence of POD in a large cohort of surgical patients. A prospective cohort study. A tertiary hospital in China. This study enrolled patients aged 65 years or older undergoing elective surgery under general anaesthesia. The participants were categorised into the sleep disturbance and no sleep disturbance groups according to their operative night SQ-NRS. The primary outcome was delirium incidence, whereas the secondary outcomes included acute kidney injury, stroke, pulmonary infection, cardiovascular complications and all-cause mortality within 1 year postoperatively. In total, 3072 patients were included in the analysis of this study. Among them, 791 (25.72%) experienced sleep disturbances on the night of operative day. Patients in the sleep disturbance group had a significantly higher risk of developing POD (adjusted OR 1.43, 95% CI 1.11 to 1.82, P = 0.005). Subgroup analysis revealed that age 65-75 years; male sex; ASA III and IV; haemoglobin more than 12 g l -1 ; intra-operative hypotension; surgical duration more than 120 min; and education 9 years or less were significantly associated with POD. No interaction was observed between the subgroups. No significant differences were observed in the secondary outcomes, such as acute kidney injury, stroke, pulmonary infection, cardiovascular complications and all-cause mortality within 1 year postoperatively. The poor subjective sleep quality on the night of operative day was independently associated with increased POD risk, especially in certain subpopulations. Optimising peri-operative sleep may reduce POD. Further research should investigate potential mechanisms and causal relationships. chictr.org.cn: ChiCTR1900028545.

Nomogram to predict the incidence of delirium in elderly patients with non-severe SARS-CoV-2 infection.

To construct and validate nomogram models that predict the incidence of delirium in elderly patients with non-severe SARS-CoV-2 infection. Elderly patients (≥65y) tested positive for SARS-CoV-2 infection at the hospital were included. We used the 3-min diagnostic Confusion Assessment Method for delirium diagnosis. Least absolute shrinkage and selection operator (LASSO) logistical regression analysis was performed to explore potential independent influencing factors of delirium. A predict model visualized by nomogram was constructed based on the confirmed variables. The predictive accuracy and clinical value of the model were evaluated using receiver operating characteristic (ROC) curves. The data of 311 elderly patients were analyzed, of whom 73 (23.47%) patients were diagnosed with delirium. Three independent influencing factors of delirium were confirmed: age (OR1.16,1.11-1.22), Glomerular filtration rate (OR 0.98,0.97-0.99), platelet-large cell ratio (1.06,1.02-1.10). These parameters were used to create a nomogram to predict the development of delirium, which showed good predictive accuracy confirmed by the ROC curves (AUC 0.82,0.76-0.88). We construct a credible nomogram to predict the development of delirium in elderly patients with Non-severe SARS-CoV-2 infection. Our finding may be useful to physicians in early prevention and treatment of delirium.

EVALUATING THE RISK OF DELIRIUM IN ELDERLY INPATIENTS IN COVID-19 INTENSIVE CARE: A PROSPECTIVE AND OBSERVATIONAL STUDY

Introduction: Delirium is dangerous, often preventable, and associated with a high financial burden and increased morbidity and mortality. This study aimed to evaluate the risk of delirium in elderly inpatients in COVID-19 intensive care units. Materials and Method: This study used a prospective and observational design. Between July and November 2022, 49 intensive care patients were admitted to a training and research hospital in northeast Turkey. The data were collected using the Patient Information Form, Critical-Care Pain Observation Tool, Ramsay Sedation Scale, and Nursing-Delirium Screening Scale. Results: The patients’ mean age was 76.90±8.29 years. The longer the length of stay in the intensive care unit, the incidence of delirium increased. The incidence of delirium increased in patients aged 70–95 years (p=0.007). Patients with delirium experienced insomnia and agitation and used more sedative drugs (p&lt;0.05). The predictors of early delirium were sedation (β=0.869), agitation (β=-0.582), and diastolic blood pressure (β=0.258). The predictors of delirium were pain (β=-0.599) and sedation (β=0.267). Conclusion: The study demonstrated that older age, agitation, sedation, pain, and diastolic blood pressure predicted delirium in elderly COVID-19 inpatients. It is necessary to identify and eliminate risk factors to reduce the risk of delirium in elderly patients. Nurses should play an active role in identifying and managing delirium in elderly COVID-19 patients. Keywords: COVID-19; Delirium; Aged; Intensive Care.

A Novel Preoperative Electroencephalogram-Derived Index to Predict Early Postoperative Delirium in Elderly Patients After Hip Fracture Surgeries: Development of a Prediction Model.

It is appealing to accurately predict postoperative delirium (POD) before surgeries. In this study, it was hypothesized that a novel electroencephalogram-derived index, the delirium index (DELi), could extract latent information regarding the predisposing factors of POD preoperatively. This study was aimed at developing a concise model that incorporated this DELi score to predict the early POD of elderly patients after hip surgeries. Elderly patients scheduled for elective hip fracture surgeries were prospectively enrolled in a tertiary care hospital from November 2020 to June 2022. DELi scores and patient characteristics (age, sex, types of fracture and surgery, the time interval between fracture and surgery, cognitive function assessed using the Montreal Cognitive Assessment (MoCA), and frailty status assessed using the FRAIL scale) were collected preoperatively as candidate predictors. POD diagnosed using the confusion assessment method (CAM) was the outcome. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to select predictors. Then, these predictors were entered into a backward logistical regression analysis to develop a prediction model. Discrimination, calibration and clinical utility were validated using the bootstrapping method. All data (144 qualified patients of 170) were used for development. POD was observed in 71 patients (49.3%). Preoperative DELi scores predicted early POD (the area under the curve (AUC) = .786, 95% confidence interval (CI): .712, .860, in internal validation). A nomogram with MoCA, FRAIL scale and DELi score was constructed with excellent discrimination (AUC = .920, 95% CI: .876, .963, in internal validation), accredited calibration (P = .733, Hosmer‒Lemeshow test), and a wide range of threshold probabilities (5% to 95%). Preoperative DELi scores predicted the early POD of elderly patients after hip surgeries. A concise prediction model was developed and demonstrated excellent discrimination.

Causes and Possible Mechanisms of Postoperative Delirium in Elderly Patients with Hip Fracture

Causes and Possible Mechanisms of Postoperative Delirium in Elderly Patients with Hip Fracture

勘误：超声引导下星状神经节阻滞对老年患者术后谵妄的研究进展

勘误：超声引导下星状神经节阻滞对老年患者术后谵妄的研究进展

Advances in Research on the Impact of Preoperative Oral Carbohydrates on Postoperative Delirium in Elderly Patients

Advances in Research on the Impact of Preoperative Oral Carbohydrates on Postoperative Delirium in Elderly Patients

Effects of liposomal bupivacaine in preoperative fascia iliac block on postoperative pain and delirium in elderly patients undergoing hip fracture surgery: a study protocol for a randomised, parallel controlled prospective clinical study

IntroductionPostoperative delirium (POD) is the most common acute fluctuating mental state change after hip fractures in older adults. Postoperative pain is a Grade A risk factor for POD and is...

Factors of delirium in elderly patients with mild cognitive impairment in long-term care facilities: a pilot study

Purpose: This study was conducted to identify factors that affect the occurrence of delirium in patients with mild cognitive impairment hospitalized in long-term care facilities. Methods: This study analyzed data collected from 2 long-term care facilities. A cross-sectional pilot study was conducted with 42 patients aged 65 years or older and mild cognitive impairment. To identify factors influencing the occurrence of delirium, multiple logistic regression analysis including general characteristics, risk-related, and medical characteristics was performed. Results: Delirium occurred in 14 (33.3%) of the participants. Hypoactivity was seen in 6 participants (42.86%), hyperactivity in 7 (50.0%), and a combination of both aspects in 1 (7.14%). The results of multiple logistic regression analysis showed that delirium in patients with mild cognitive impairment in long-term care facilities had a high occurrence in patients wearing diapers. Conclusion: This study identified the occurrence of delirium in patients with mild cognitive impairment hospitalized in long-term care facilities. One of the factors affecting the occurrence of delirium was “wearing diapers.” The findings can be used to train nurses on delirium evaluation and intervention and to help prevent and manage delirium in long-term care facilities. This study suggests that further research is necessary to reduce the incidence of delirium.

Risk factors, preventive interventions, overlapping symptoms, and clinical measures of delirium in elderly patients.

Delirium is an acute reversible neuropsychiatric syndrome caused by multiple factors. It is associated with many adverse clinical outcomes including cognitive impairment, functional decline, prolonged hospitalization, and increased nursing service. The prevalence of delirium was high in department of cardiology, geriatric, and intensive care unit of hospital. With the increase in the aged population, further increases in delirium seem likely. However, it remains poorly recognized in the clinical practice. This article comprehensively discusses the latest research perspectives on the epidemiological data, risk factors, preventive interventions, overlapping symptoms, and clinical measures of delirium, including specific measures to manage delirium in clinical real-world situations. This article helps readers improve their knowledge and understanding of delirium and helps clinicians quickly identify and implement timely therapeutic measures to address various delirium subtypes that occur in the clinical settings to ensure patients are treated as aggressively as possible.

A pre-anesthetic bolus of ketamine versus dexmedetomidine for prevention of postoperative delirium in elderly patients undergoing emergency surgery: a randomized, double-blinded, placebo-controlled study

BackgroundWe aimed to evaluate whether a single dose of ketamine or dexmedetomidine before induction of general anesthesia could reduce the incidence of postoperative delirium (primary outcome) or cognitive dysfunction (secondary outcome) in elderly patients undergoing emergency surgery.Patients and methodsThis randomized, double-blinded, placebo-controlled trial included 60 elderly patients who were scheduled for emergency surgery. The patients were randomly assigned into one of three groups (n = 20): group I received 0.9% normal saline, group II received 1 µg/kg dexmedetomidine, and group III received 1 mg/kg ketamine right before anesthesia induction. Patients were observed for three days after surgery and tested for postoperative delirium and cognitive dysfunction using the delirium observation screening scale and the mini-mental state examination score, respectively.ResultsThe dexmedetomidine group had the lowest incidence of delirium (p = 0.001) and cognitive dysfunction (p = 0.006) compared to the ketamine and placebo groups. The multivariate logistic regression model revealed that dexmedetomidine reduced the incidence of postoperative delirium by 32% compared to placebo (reference) (OR = 0.684, 95% CI: 0.240–0.971, p = 0.025), whereas ketamine increased the risk by threefold (OR = 3.012, 95% CI: 1.185–9.681, p = 0.013). Furthermore, dexmedetomidine reduced the incidence of postoperative cognitive dysfunction by 62% (OR = 0.375, 95% CI: 0.091–0.543, p = 0.012), whereas ketamine increased the risk by 4.5 times (OR = 4.501, 95% CI: 1.161–8.817, p = 0.006).ConclusionA single pre-anesthetic bolus of dexmedetomidine is a practical choice for preventing postoperative delirium in elderly patients undergoing emergency surgery.Trial registrationThis study was approved by the Ethics Committee of Aswan University Hospital (approval number: aswu/548/7/2021; registration date: 06/07/2021) and registered on ClinicalTrials.gov (NCT05341154) (22/04/2022).

Evaluating the effects of S-ketamine on postoperative delirium in elderly patients following total hip or knee arthroplasty under intraspinal anesthesia: a single-center randomized, double-blind, placebo-controlled, pragmatic study protocol

IntroductionPostoperative delirium (POD) is an acute, transient brain disorder associated with decreased postoperative quality of life, dementia, neurocognitive changes, and mortality. A small number of trials have explored the role of S-ketamine in the treatment of POD due to its neuroprotective effects. Surprisingly, these trials have failed to yield supportive results. However, heterogeneity in delirium assessment methodologies, sample sizes, and outcome settings as well as deficiencies in S-ketamine use methods make the evidence provided by these studies less persuasive. Given the severe impact of POD on the health of elderly patients and the potential for S-ketamine to prevent it, we believe that designing a large sample size, and rigorous randomized controlled trial for further evaluation is necessary.MethodsThis is a single-center, randomized, double-blind, placebo-controlled, pragmatic study. Subjects undergoing total hip or knee arthroplasty will be randomized in a 1:1 ratio to intervention (n = 186) and placebo (n = 186) groups. This trial aims to explore the potential role of S-ketamine in the prevention of POD. Its primary outcome is the incidence of POD within 3 postoperative days. Secondary outcomes include the number of POD episodes, the onset and duration of POD, the severity and subtype of POD, pain scores and opioid consumption, sleep quality, clinical outcomes, and safety outcomes.DiscussionTo our knowledge, this is the first pragmatic study that proposes to use S-ketamine to prevent POD. We reviewed a large body of literature to identify potential preoperative confounding variables that may bias associations between the intervention and primary outcome. We will use advanced statistical methods to correct potential confounding variables, improving the test’s power and external validity of test results. Of note, the patient population included in this trial will undergo intraspinal anesthesia. Although large, multicenter, randomized controlled studies have found no considerable difference in the effects of regional and general anesthesia on POD, patients receiving intraspinal anesthesia have less exposure to at-risk drugs, such as sevoflurane, propofol, and benzodiazepines, than patients receiving general anesthesia. At-risk drugs have been shown to negatively interfere with the neuroprotective effects of S-ketamine, which may be the reason for the failure of a large number of previous studies. There is currently a lack of randomized controlled studies evaluating S-ketamine for POD prevention, and our trial helps to fill a gap in this area.Trial registration: http://www.chictr.org.cn, identifier ChiCTR2300075796.

Geriatric nutritional risk index independently predicts delirium in older patients in intensive care units: A multicenter cohort study

BackgroundMalnutrition is associated with clinical outcomes in several diseases. However, the role of malnutrition in the risk of delirium in elderly patients in intensive care units (ICU) remains unclear. This study aimed to elucidate the association between the Geriatric Nutritional Risk Index (GNRI) and the risk of delirium in elderly patients in the ICU. MethodsElderly patients from the Medical Information Mart for Intensive Care IV (MIMIC-IV) and the eICU Collaborative Research Database (eICU-CRD) were included in this study, totaling 11,310 and 5,627, respectively. All subjects were stratified according to their GNRI score: those with no nutritional risk (GNRI > 98), mild nutritional risk (92 ≤ GNRI ≤ 98), moderate nutritional risk (82 ≤ GNRI ≤ 92), and severe nutritional risk (GNRI < 82). The primary outcome was delirium. ResultsThe GNRI in MIMIC-IV and eICU-CRD were 93.82 (84.88, 101.26) and 83.39 (75.95, 89.35), respectively. Compared to the cohort without nutritional risk, there was an increased risk of delirium in patients with mild nutritional risk (OR: 1.39, 95 % CI: 1.23–1.58), moderate nutritional risk (OR: 1.72, 95 % CI: 1.52–1.95), and severe nutritional risk (OR: 2.07, 95 % CI: 1.79–2.39). Inclusion of the GNRI score in the multivariate models improved the prediction of delirium. Similar results were found in the eICU-CRD database. ConclusionsNutritional assessment using the GNRI may be an independent predictor of the development of delirium in elderly patients in the ICU. The addition of the GNRI score to the delirium prediction model improves its predictive accuracy.

The correlation between burst suppression on electroencephalogram during laparoscopic surgery and emergence delirium in elderly patients

Objective: To investigate the relationship between intraoperative electroencephalogram burst suppression (BS) and emergence delirium (ED) in elderly patients undergoing elective laparoscopic surgery under total intravenous anesthesia (TIVA). Methods: From October 2017 to September 2019, a total of 358 elderly patients who underwent elective laparoscopic surgery under TIVA at Xiangya Hospital, Central South University, were included. Patients were divided into two groups based on the confusion assessment method for the intensive care unit (CAM-ICU) assessment conducted before leaving the post-anesthesia care unit (PACU): the ED group [n=63, 46 males, 17 females, average age of (70.8±0.6) years] and the non-ED group [n=295, 220 males, 75 females, average age of (69.7±0.2) years]. Preoperative general information, intraoperative conditions, and intraoperative electroencephalogram BS status were collected. A multivariate logistic regression model was employed to identify risk factors associated with ED. Results: In the ED group, the duration of surgery, intraoperative blood loss, the burst suppression ratio (BSR)>10% lasting for more than 1 minute were (224.4±9.6) min, (240.8±33.9) ml, 36.5% (23/63), respectively, which were higher than those of the non-ED group [(204.7±3.6) min, (150.5±9.2) ml, 21.7% (64/295), all P<0.05]. Multivariate logistic regression analysis revealed that a longer duration of education was a protective factor for ED (OR=0.904, 95%CI: 0.833-0.982,P=0.016), whereas increased intraoperative blood loss (OR=1.002, 95%CI: 1.000-1.003, P=0.013) and BSR>10% lasting for more than 1 minute (OR=2.131, 95%CI: 1.004-4.524,P=0.049) were identified as risk factors for ED. Conclusion: In elderly patients undergoing laparoscopic surgery under TIVA, intraoperative electroencephalogram BS may be a risk factor for ED.

Inflammatory and nutritional markers predict the risk of post-operative delirium in elderly patients following total hip arthroplasty.

This study intended to explore whether albumin-associated inflammatory and nutritional markers could predict post-operative delirium (POD) in older patients after total hip arthroplasty (THA). In addition, we established a nomogram model for POD prediction. Totally, 254 elderly cases who received THA were included. Clinical and laboratory data of these patients were retrospectively collected. Albumin-associated inflammatory and nutritional markers included neutrophil-to-albumin ratio (NAR), CRP-to-albumin ratio (CAR), prognostic nutritional index (PNI), and systemic inflammation score (SIS). The LASSO, univariate and multivariate logistic regression analyses were utilized to screen risk factors. A nomogram model was developed according to the results of multivariate regression analyses. Among 254 patients, 49 cases had POD with an incidence of 19.3%. LASSO regression and multivariate logistic analyses suggested that preoperative NAR, preoperative PNI, preoperative SIS, and age >75 years were risk factors for POD. A nomogram model was developed according to the results of multivariate logistic analyses. The calibration curve suggested that the predicted probability of this nomogram model was in good line with the actual probability. The DCA showed that this nomogram model had net benefits for the prediction of POD for elderly patients following THA. Albumin-associated inflammatory and nutritional markers including NAR, PNI, and SIS could predict POD in elderly patients following THA.

Risk factors associated with postoperative delirium in elderly patients undergoing hip surgery.

We retrospectively analyzed the occurrence of postoperative delirium following hip surgery and the associated risk factors. The aim was to establish a clinical foundation for preventing postoperative delirium after hip surgery. We retrospectively selected elderly patients who had hip surgery at our hospital between January 2022 and August 2022. We included patients who experienced delirium in the observation group and those who did not encounter delirium in the control group. We then proceeded to compare various indicators among these two groups of patients. We analyzed a total of 97 cases of hip surgery, and among them, 32 cases experienced postoperative delirium, resulting in an incidence rate of 32.9%. Various factors were found to be linked to the development of postoperative delirium, including age, height, gender (male), preoperative erythrocyte sedimentation rate (ESR), postoperative ESR, preoperative lactate levels, pain scores on the first day after surgery, type of surgical procedure, and the occurrence of delirium in the post-anesthesia care unit (PACU delirium). Additionally, it was observed that 75% of patients who had PACU delirium also experienced postoperative delirium. Postoperative delirium in patients who have hip surgery had an incidence rate of 32.9%. This phenomenon is linked to various factors that pose a risk, such as the patient age, height, gender, preoperative ESR levels, postoperative ESR levels, preoperative lactate levels, pain scores on the day following surgery, and the specific surgical procedure performed. The likelihood of experiencing delirium increases by 12% for every additional 10 years in patient age. Additionally, the occurrence of delirium in the PACU is a strong indicator of the likelihood of experiencing postoperative delirium.

Correlation between malnutrition and delirium in elderly patients with severe pneumonia undergoing invasive mechanical ventilation

To investigate the relationship between malnutrition and delirium and its effect on prognosis in elderly patients with severe pneumonia undergoing invasive mechanical ventilation. A prospective observational study was conducted. Patients with severe pneumonia aged ≥ 60 years old who underwent invasive mechanical ventilation admitted to department of critical care medicine of the Second People's Hospital of Lianyungang from January 2021 to December 2022 were enrolled. The confusion assessment method (CAM) was used to evaluate the delirium of the patients in intensive care unit (ICU). The score of CAM ≥ 1 was defined as delirium. Mini nutritional assessment short-form (MNA-SF) was used to assess the nutritional status of patients, and MNA-SF score ≤ 7 was defined as malnutrition. Patients were divided into delirium group and non-delirium group according to whether delirium occurred. The differences in clinical indicators, length of ICU stay, duration of mechanical ventilation and wake-up time after drug withdrawal were compared between the two groups. After 28 days of short-term follow-up, the patients were divided into death group and survival group, and the differences in the incidence of delirium and malnutrition between the two groups were compared. Binary multivariate Logistic regression analysis was used to screen the risk factors for delirium in elderly patients with severe pneumonia undergoing invasive mechanical ventilation. Kaplan-Meier survival curve was used to analyze the effect of delirium on prognosis. A total of 132 elderly patients with severe pneumonia undergoing invasive mechanical ventilation were enrolled, of whom 98 survived and 34 died within 28 days, with a mortality of 25.76%. The incidence of malnutrition and delirium in the death group was significantly higher than that in the survival group (61.76% vs. 37.76%, 64.71% vs. 26.53%, both P < 0.05), and the MNA-SF score was significantly lower than that in the survival group (6.32±1.80 vs. 8.72±2.23, P < 0.01). Procalcitonin (PCT), interleukin-6 (IL-6) and blood lactic acid (Lac) in the death group were significantly higher than those in the survival group [PCT (μg/L): 4.47 (2.69, 10.39) vs. 2.77 (1.28, 5.94), IL-6 (ng/L): 204.08 (126.12, 509.85) vs. 120.46 (60.67, 290.99), Lac (mmol/L): 5.14 (2.75, 8.60) vs. 3.13 (2.16, 4.30), all P < 0.05], and the wake-up time after drug withdrawal was significantly longer than that in the survival group (minutes: 33.94±8.51 vs. 28.92±7.03, P < 0.01). Among 132 elderly patients with severe pneumonia undergoing invasive mechanical ventilation, 48 patients had delirium during ICU stay, and 84 patients did not have delirium. The incidence of delirium was 36.36%. The 28-day mortality in the delirium group was significantly higher than that in the non-delirium group (45.83% vs. 14.29%, P < 0.01), and the MNA-SF score was significantly lower than that in the non-delirium group (6.46±1.77 vs. 9.05±2.15, P < 0.01), the length of ICU stay, duration of mechanical ventilation, and wake-up time after drug withdrawal were also significantly longer than those in the non-delirium group [length of ICU stay (days): 13.40±9.59 vs. 10.06±7.81, duration of mechanical ventilation (hours): 197.06±89.80 vs. 138.81±82.30, wake-up time after drug withdrawal (minutes): 35.85±7.01 vs. 26.99±6.12, all P < 0.05]. Binary multivariate Logistic regression analysis showed that malnutrition [odds ratio (OR) = 7.527, 95% confidence interval (95%CI) was 2.585-21.917], Lac (OR = 5.345, 95%CI was 1.733-16.483), wake-up time after drug withdrawal (OR = 6.653, 95%CI was 2.021-21.904) were independent risk factors for delirium during ICU stay in elderly patients with severe pneumonia undergoing invasive mechanical ventilation (all P < 0.01). Kaplan-Meier survival analysis showed that the 28-day cumulative survival rate of patients in the delirium group was significantly lower than that in the non-delirium group (54.17% vs. 85.71%), and the difference was statistically significant (Log-Rank test: χ2 = 16.780, P < 0.001). The risk factors for delirium in elderly patients with severe pneumonia undergoing invasive mechanical ventilation during ICU stay include malnutrition, Lac, and wake-up time after drug withdrawal. The occurrence of delirium is closely related to poor prognosis.

Prophylactic effect of exogenous melatonin and melatonin receptor agonists on postoperative delirium in elderly patients: a systemic review and meta-analysis of randomized controlled trials.

The prophylactic effect of exogenous melatonin and melatonin receptor agonists (MMRAs) on postoperative delirium (POD) in elderly patients remains controversial. This study aimed to assess the prophylactic effect of MMRAs on POD by conducting a systemic review and meta-analysis of randomized controlled trials (RCTs). We systematically searched four electronic databases including PubMed, Web of Science, Cochrane Library, and Embase for the eligible studies up to February 28, 2023. The Cochrane risk of bias tool was used for assessing the risk of bias in the included RCTs. The occurrence of POD was the primary outcome. The quality of evidence was evaluated by Grading of Recommendations Assessment, Development, and Evaluation. A total of 11 RCTs comprising patients (MMRA group: 777 patients and placebo group: 781 patients) were included. The results of the meta-analysis showed that the MMRA group had a lower occurrence of POD than the placebo group (risk ratio = 0.70, 95% confidence interval: 0.51-0.97, P < 0.05, I2 = 59%). The subgroup analysis showed that melatonin significantly reduced the occurrence of POD (moderate-quality evidence), whereas ramelteon and tryptophan had no significant impact (moderate-quality evidence). Existing evidence suggested that perioperative use of melatonin can prevent POD in elderly patients.