Risk Factors for Postoperative Delirium in Abdominal Surgery: A Proposal of a Postoperative Delirium Risk Score in Abdominal Surgery

Association of preoperative frailty and postoperative delirium in older cancer patients undergoing elective abdominal surgery: A prospective observational study in Taiwan

BACKGROUND

Postoperative delirium (POD) is a common surgical complication in elderly patients. As frailty is a relatively novel concept, its clinical significance for POD has seldom been examined. This study aimed to investigate the association between frailty and POD in aged cancer patients undergoing elective abdominal surgery in Taiwan.

METHODS

We prospectively enrolled 345 consecutive patients aged ≥65 years with newly diagnosed cancer who underwent elective abdominal surgery between 2016 and 2018. Frailty assessment was performed using the Comprehensive Geriatric Assessment (CGA). POD was assessed daily using the Confusion Assessment Method from postoperative day 1 until discharge. Patients were allocated into fit and frail groups.

RESULTS

POD occurred in 19 (5.5%) of 345 patients. POD incidence was 1.6%, 3.1%, 4.8%, 11.5%, and 10.0% in patients with 0, 1, 2, 3, and 4+ frail conditions, respectively, which presented a positive linear correlation among patients with an increased number of frail conditions and POD incidence. Based on CGA, 159 (46.1%) and 186 (53.9%) patients were allocated to fit and frail groups, respectively. POD incidence was 2.5% and 8.1% for the fit and frail groups, respectively. Frailty status was an independent risk factor for POD occurrence in multivariate analysis.

CONCLUSION

Our study identified frailty as an independent risk factor for POD in aged Taiwanese cancer patients undergoing elective abdominal surgery. Given the high prevalence of frailty among older cancer patients, preoperative assessment is important to identify high risk of POD and to improve the quality of postoperative care.

Risk Factors for Delirium after Deep Brain Stimulation Surgery under Total Intravenous Anesthesia in Parkinson's Disease Patients

BACKGROUND

Postoperative delirium (POD) is associated with perioperative complications and mortality. Data on the risk factors for delirium after subthalamic nucleus deep brain stimulation (STN-DBS) surgery is not clarified in Parkinson's disease (PD) patients receiving total intravenous anesthesia. We aimed to investigate the risk factors for delirium after STN-DBS surgery in PD patients.

METHODS

The retrospective cohort study was conducted, including 131 PD patients who underwent STN-DBS for the first time under total intravenous anesthesia from January to December 2021. Delirium assessments were performed twice daily for 7 days after surgery or until hospital discharge using the confusion assessment method for the intensive care unit. Multivariate logistic regression analysis was used to determine the risk factor of POD.

RESULTS

In total, 22 (16.8%) of 131 patients were in the POD group, while the other 109 patients were in the Non-POD group. Multivariate logistic regression analysis showed that preoperative Mini-mental State Examination score [odds ratio = 0.855, 95% confidence interval = 0.768-0.951, p = 0.004] and unified Parkinson's disease rating scale part 3 (on state) score (odds ratio = 1.061, 95% confidence interval = 1.02-1.104, p = 0.003) were independently associated with delirium after surgery.

CONCLUSIONS

In this retrospective cohort study of PD patients, a lower Mini-mental State Examination score and a higher unified Parkinson's disease rating scale part 3 (on state) score were the independent risk factors for delirium after STN-DBS surgery in PD patients under total intravenous anesthesia.

Needs assessment survey of healthcare providers' perceptions and practices regarding delirium prevention at a university medical center

Background: Despite the high prevalence and serious implications of delirium, identification, tracking, and documentation of the condition remain a challenge for the health care team, impeding management of patients. This survey is the first phase of a qualitative study to build a conversational agent-based tool for screening and managing delirium-prone patients. Objectives: To assess healthcare providers' perceptions of delirium management, focusing on patient assessment, therapeutic interventions, and subsequent communication and documentation. Design: An electronic web-based survey was distributed to healthcare providers identified as caring for inpatient acutely ill older adults admitted for medical and orthopedic surgery needs. Respondent contact information was removed to preserve anonymity. Setting: A 1,000 bed university-affiliated teaching hospital in an urban setting. Participants: 23 residents in family practice, 36 residents in internal medicine, and a total of 492 advanced care nurses, nurses, and clinical staff. Approach: The analysis of survey responses provided insight into providers' current experiences with delirium assessment tools including computerized documentation, as well as their perceptions and attitudes toward delirium prevention. Key results: Most respondents (89%) thought delirium could be prevented, and 85% thought targeting delirium risk factors was helpful. Fifty one percent reported patients' loneliness and need for companionship, and 65% believed delirium was linked to higher mortality. Only 14% of respondents thought existing Electronic Health Record (EHR) alerts to identify high-risk delirium patients were useful, and 38% thought current delirium assessment protocols were helpful. In addition, 33% of nurses never received formal delirium prevention training, and 48% indicated that they needed improved systems to assess and manage patients at risk for delirium. Conclusion: A majority of providers affirmed that current delirium protocols are helpful; however, existing screening instruments and methods for documentation are cumbersome, resulting in incomplete or limited documentation of episodes. These barriers lead to an understatement of evidence available for continuous improvement of the patient management process.

The assessment of risk factors for postoperative delirium using cubic spline curves in gastroenterological surgery

PURPOSE

Delirium is associated with longer hospital stays and increased medical costs and mortality. This study explored the risk factors for postoperative delirium in gastroenterological surgery and investigated the association between qualitative changes in risk factors and the incidence of postoperative delirium.

METHODS

A total of 418 patients > 18 years old who underwent gastroenterological surgery at our department between April 2018 and September 2019 were included. Risk factors were identified by comparing patients with and without postoperative delirium. Continuous variables were evaluated graphically using cubic spline curves. A logistic regression analysis was performed to assess independent risk factors.

RESULTS

The incidence of postoperative delirium was 6.9%. The cubic spline curve showed that the incidence of postoperative delirium began to increase at 50 years old and increased sharply at 70 years old. A multiple logistic regression analysis of patients > 50 years old identified 5 risk factors: age ≥ 70 years, preoperative serum albumin ≤ 3.8 g/dL, psychosis, sedative-hypnotics, and intensive-care unit admission.

CONCLUSION

The risk of postoperative delirium increases progressively at 50 years old and sharply at 70 years old. Advanced age, preoperative hypoalbuminemia, psychosis, sedative-hypnotics, and intensive-care unit admission are risk factors for postoperative delirium in patients > 50 years old undergoing gastroenterological surgery.

Development and validation of a risk score for predicting postoperative delirium after major abdominal surgery by incorporating preoperative risk factors and surgical Apgar score

STUDY OBJECTIVE

To develop and validate a simple delirium-predicting scoring system in patients undergoing major abdominal surgery by incorporating preoperative risk factors and intraoperative surgical Apgar score (SAS).

DESIGN

Observational retrospective cohort study.

SETTING

A tertiary general hospital in China.

PATIENTS

1055 patients who received major abdominal surgery from January 2015 to December 2019.

MEASUREMENTS

We collected data on preoperative and intraoperative variables, and postoperative delirium. A risk scoring system for postoperative delirium in patients after major open abdominal surgery was developed and validated based on traditional logistic regression model. The elastic net algorithm was further developed and evaluated.

MAIN RESULTS

The incidence of postoperative delirium was 17.8% (188/1055) in these patients. They were randomly divided into the development (n = 713) and validation (n = 342) cohorts. Both the logistic regression model and the elastic net regression model identified that advanced age, arrythmia, hypoalbuminemia, coagulation dysfunction, mental illness or cognitive impairments and low surgical Apgar score are related with increased risk of postoperative delirium. The elastic net algorithm has an area under the receiver operating characteristic curve (AUROC) of 0.842 and 0.822 in the development and validation cohorts, respectively. A prognostic score was calculated using the following formula: Prognostic score = Age classification (0 to 3 points) + arrythmia + 2 * hypoalbuminemia + 2 * coagulation dysfunction + 4 * mental illness or cognitive impairments + (10-surgical Apgar score). The 22-point risk scoring system had good discrimination and calibration with an AUROC of 0.823 and 0.834, and a non-significant Hosmer-Lemeshow test P = 0.317 and P = 0.853 in the development and validation cohorts, respectively. The bootstrapping internal verification method (R = 1000) yielded a C-index of 0.822 (95% CI: 0.759-0.857).

CONCLUSION

The prognostic scoring system, which used both preoperative risk factors and surgical Apgar score, serves as a good first step toward a clinically useful predictive model for postoperative delirium in patients undergoing major open abdominal surgery.

Relation of serum melatonin levels to postoperative delirium in older patients undergoing major abdominal surgery

Objective

Postoperative delirium (POD) is a perennial and distressing complication in older patients, and it may be caused by various factors. This study aimed to determine whether serum melatonin levels are associated with POD in older patients who undergo major abdominal surgery.

Methods

We collected serum samples from patients undergoing major abdominal surgery. Melatonin was measured by enzyme-linked immunosorbent assay and delirium was assessed by the Confusion Assessment Method after surgery. We classified the patients into the POD group and non-POD group.

Results

A total of 120 patients met the inclusion criteria and 104 patients were included in the analysis. Postoperative serum melatonin levels were significantly lower than preoperative levels. Multivariate analyses showed that a longer duration of anesthesia (odds ratio [OR] = 1.29, 95% confidence interval [CI] = 1.02–1.64), advanced age (OR = 3.36, 95% CI = 1.37–8.22), and lower postoperative levels of melatonin (OR = 0.50, 95% CI = 0.25–1.00) were associated with POD.

Conclusions

Serum melatonin levels significantly decline after surgery and anesthesia. Significantly decreased serum melatonin concentrations postoperatively may be a biomarker for predicting POD in older patients undergoing major abdominal surgery with general anesthesia.

Risk factors for postoperative delirium after spinal surgery: a systematic review and meta-analysis

BACKGROUND

Postoperative delirium is common in older patients after spinal surgery. Many reports investigating the risk factors for delirium after spinal surgery have been published recently.

METHODS

A literature search was performed using the Cochrane Library, Web of Science, PubMed, Embase, and Springer databases from inception to February 2019. Relevant studies involving patients with delirium who underwent spinal surgery were included if the studies contained data about blood transfusion or other related factors, such as haemoglobin, haematocrit, and blood loss levels. The Newcastle-Ottawa Scale was used for the study-quality evaluation. The pooled odds ratios or (standard) mean differences of the individual risk factors were estimated using the Mantel-Haenszel or inverse-variance methods.

RESULTS

Fifteen observational studies met the inclusion criteria; the studies included a total of 583,290 patients (5431 patients with delirium and 577,859 patients without delirium). In addition to an advanced age, the results of the meta-analyses showed that living in an institution, diabetes, cerebral vascular diseases, pulmonary diseases, opioid use, length of surgery, intraoperative blood loss, blood transfusions, intraoperative infusion, preoperative albumin, postoperative albumin, preoperative haematocrit, postoperative haematocrit, preoperative haemoglobin, postoperative haemoglobin, preoperative sodium, postoperative sodium, Mini-Mental State Examination score, inability to ambulate, depression, number of medications, and treatment with multiple drugs (> three types) were significantly associated with delirium.

CONCLUSION

The above-mentioned risk factors can be used to identify high-risk patients, and the appropriate prophylaxis strategies should be implemented to prevent delirium after spinal surgery.

Prospective Study of Factors Associated With Postoperative Delirium After Urgent Abdominal Surgery

INTRODUCTION

Delirium is a frequent complication in elderly patients after urgent abdominal surgery.

METHODS

Prospective study of consecutive patients aged ≥65years who had undergone urgent abdominal surgery from 2017-2019. The following variables were recorded: age, sex, ASA, physiological state, cognitive impairment, frailty (FRAIL Scale), functional dependence (Barthel Scale), quality of life (Euroqol-5D-VAS), nutritional status (MNA-SF), preoperative diagnosis, type of surgery (BUPA Classification), approach and diagnosis of postoperative delirium (Confusion Assessment Method). Univariate and multivariate analyses were performed to analyze the correlation of these variables with delirium.

RESULTS

The study includes 446 patients with a median age of 78years, 63.6% were ASA ≥III and 8% had prior cognitive impairment. 13.2% were frail and 5.4% of the patients had a severe or total degree of dependence. 13.6% developed delirium in the postoperative period. In the univariate analysis, all the variables were statistically significant except for sex, type of surgery (BUPA) and duration. In the multivariate analysis the associated factors were: age (P<.001; OR: 1,08; 95%CI: 1,038-1,139), ASA (P=.026; OR: 3.15; 95%CI: 1.149-8.668), physiological state (P<.001; OR: 5.8; 95%CI: 2.176-15.457), diagnosis (P=.006) and cognitive impairment (P<.001; OR: 5.8; 95%CI: 2.391-14.069).

CONCLUSION

The factors associated with delirium are age, ASA, physiological state in the emergency room, preoperative diagnosis and prior cognitive impairment.

Intranuclear delivery of synthetic nuclear factor-kappa B p65 reduces inflammasomes after surgery

Patients undergoing surgery can suffer from various complications, including post-operative bleeding, local or systematic infection, and neurologic disorders. Major surgery can initiate innate immune responses and trigger overproduction of inflammatory mediators, which can contribute to organ dysfunction. Inflammasomes are innate immune complexes, which are connected to the pathogenesis of various diseases, including atherosclerosis, hemorrhagic brain injury, and Alzheimer's disease. In the present study, we hypothesized that nucleotide-binding oligomerization domain-containing-like receptor protein (NLRP) inflammasomes may have a role in the pathological effects of surgery. Therefore, we designed a protein inhibitor of nuclear factor kappa B (NF-κB) p65 transcripts, called nt-p65-TMD (nuclear transducible (nt) transcription modulated domain (TMD) of RelA (p65)), that can penetrate the nucleus, and evaluated its therapeutic efficacy for dampening surgery-induced inflammasome activation. It was found that the nt-p65-TMD significantly reduced the NLRP1 inflammasome complex components (NLRP1, ASC, and Caspase-1) and interleukin (IL)-1β and IL-18 productions in the spleen after surgery. In the spleen, specific cell population and selective mediators were altered after surgery with/without nt-p65-TMD treatment. Also, we found that treatment of nt-p65-TMD decreased cell death in the spleen after surgery. Therefore, nt-p65-TMD is a potential novel strategy for reducing surgery-induced NLRP1 inflammasome and complications.

Psychiatric diagnoses and their influencing factors in patients complaining of sleep problems: A study of a psychiatric consultation-liaison service

Objective This study aimed to identify misdiagnosed or undiagnosed psychiatric disorders and the factors associated with these disorders in patients with sleep problems who are referred to a consultation-liaison service. Method Records of all inpatients receiving a consultation from the Psychiatry Department between January and December 2016 were retrospectively reviewed. Psychiatric diagnoses were analyzed using descriptive statistics, and the factors associated with the risk of these disorders in patients with sleep problems were determined by multiple logistic regression analysis. Results Of the 331 referral patients whose referral reason was simply having trouble in sleeping, only 97 patients were diagnosed with primary sleep disorder after consultation. The recognition rate of psychiatric disorders in inpatients with sleep problems among nonpsychiatric physicians was 29.3%. Anxiety (107, 45.7%) was the most common psychiatric diagnosis in patients with sleep problems followed by organic mental disorder (83, 35.5%), depression (37, 15.8%), and other mental disorders (8, 3.4%). Multiple logistic regression analysis revealed that a course >1 month (OR = 3.656, 95% CI = 2.171-6.156, p = 0.000) and sleep-wake rhythm disturbances (OR = 25.008, 95% CI = 5.826-107.341, p = 0.000) were associated with increased risks of psychiatric disorders. Conclusions The study showed that recognition rate of psychiatric disorders in inpatients with sleep problems was very low. A course >1 month and sleep-wake rhythm disturbances were associated with increased risks of disorders and could be used as indicators by nonpsychiatric physicians to improve diagnoses.

Delirium Prediction using Machine Learning Models on Preoperative Electronic Health Records Data

Electronic Health Records (EHR) are mainly designed to record relevant patient information during their stay in the hospital for administrative purposes. They additionally provide an efficient and inexpensive source of data for medical research, such as patient outcome prediction. In this study, we used preoperative Electronic Health Records to predict postoperative delirium. We compared the performance of seven machine learning models on delirium prediction: linear models, generalized additive models, random forests, support vector machine, neural networks, and extreme gradient boosting. Among the models evaluated in this study, random forests and generalized additive model outperformed the other models in terms of the overall performance metrics for prediction of delirium, particularly with respect to sensitivity. We found that age, alcohol or drug abuse, socioeconomic status, underlying medical issue, severity of medical problem, and attending surgeon can affect the risk of delirium.