Risk factors and incidence of postoperative delirium in elderly patients after elective and emergency surgery

The effectiveness of preoperative delirium prevention in intermediate to high-risk older surgical patients: A systematic review

BACKGROUND

Few reviews have addressed delirium prevention among intermediate to high-risk older surgical patients.

AIMS

To map preoperative delirium prevention interventions for older surgical patients at intermediate to high risk of developing delirium, assess outcomes and identify gaps in knowledge.

DESIGN

Systematic narrative review of randomised controlled trials reported following the PRISMA checklist.

METHODS

A systematic search was conducted of the literature published from 1990 to October 2022 in Medline, CINAHL and Ageline and of the grey literature in Google Scholar. Randomised controlled trials were retrieved that assessed the effectiveness of preoperative delirium prevention interventions for older surgical patients at intermediate to high risk of delirium. Data were extracted using a data extraction tool, and results were tabulated. Studies were assessed for bias using the Cochrane Collaboration Risk of Bias tool.

RESULTS

Twenty-one studies met the selection criteria including N = 5096 participants. Two studies tested cognitive training, two studies tested fascia iliaca compartment block and one study assessed femoral nerve block. Ten studies tested prophylactic medications including methylprednisolone. Five studies investigated geriatric assessment and management. One study assessed transcutaneous electrical acupoint stimulation. In the two studies testing fascia iliaca compartment block, there was a reduction in postoperative delirium for orthopaedic patients. Methylprednisolone reduced postoperative delirium in orthopaedic patients and in those undergoing gastrointestinal surgery. Results of all other interventions on the occurrence of postoperative delirium and additional outcomes including the severity and duration of delirium were inconclusive.

CONCLUSIONS

Despite the promising results for fascia iliaca compartment block and methylprednisolone, there is limited knowledge regarding evidence-based delirium prevention interventions. Most studies had small sample sizes indicating that the current evidence is exploratory. There is an urgent need for the funding and conduct of trials to test preventative interventions for older surgical patients at intermediate to high risk of developing delirium.

Impact of sarcopenia in elderly patients undergoing elective total hip arthroplasty on postoperative outcomes: a propensity score-matched study

OBJECTIVE

Frailty poses a crucial risk for postoperative complications in the elderly, with sarcopenia being a key component. The impact of sarcopenia on postoperative outcomes after total hip arthroplasty (THA) is still unclear. This study investigated the potential link between sarcopenia and postoperative outcomes among elderly THA patients.

METHODS

Totally 198 older patients were enrolled in this study. Sarcopenia in this group was determined by assessing the skeletal muscle index, which was measured using computed tomography at the 12th thoracic vertebra and analyzed semi-automatically with MATLAB R2020a. Propensity score matching (PSM) was employed to evaluate postoperative complications of grade II and above (POCIIs).

RESULTS

The variables balanced using PSM contained age, sex and comorbidities including hypertension, diabetes, hyperlipidemia and COPD. Before PSM, sarcopenic patients with reduced BMI (24.02 ± 0.24 vs. 27.11 ± 0.66, P < 0.001) showed higher POCIIs rates (48.31% vs. 15%, P = 0.009) and more walking-assisted discharge instances (85.96% vs. 60%, P = 0.017) compared with non-sarcopenia patients. After PSM, this group maintained reduced BMI (23.47 ± 0.85 vs. 27.11 ± 0.66, P = 0.002), with increased POCIIs rates (54.41% vs. 15%, P = 0.002) and heightened reliance on walking assistance at discharge (86.96% vs. 60%, P = 0.008).

CONCLUSION

Sarcopenia patients exhibited a higher incidence of POCIIs and poorer physical function at discharge. Sarcopenia could serve as a valuable prognostic indicator for elderly patients undergoing elective THA.

Understanding the association between pain and delirium in older hospital inpatients: systematic review and meta-analysis

OBJECTIVE

Delirium and pain are common in older adults admitted to hospital. The relationship between these is unclear, but clinically important. We aimed to systematically review the association between pain (at rest, movement, pain severity) and delirium in this population.

METHODS

PubMed, EMBASE, CINAHL, PsycINFO, Cochrane and Web of Science were searched (January 1982-November 2022) for Medical Subject Heading terms and synonyms ('Pain', 'Analgesic', 'Delirium'). Study eligibility: (1) validated pain measure as exposure, (2) validated delirium tool as an outcome; participant eligibility: (1) medical or surgical (planned/unplanned) inpatients, (2) admission length ≥ 48 h and (3) median cohort age over 65 years. Study quality was assessed with the Newcastle Ottawa Scale. We collected/calculated odds ratios (ORs) for categorical data and standard mean differences (SMDs) for continuous data and conducted multi-level random-intercepts meta-regression models. This review was prospectively registered with PROSPERO [18/5/2020] (CRD42020181346).

RESULTS

Thirty studies were selected: 14 reported categorical data; 16 reported continuous data. Delirium prevalence ranged from 2.2 to 55%. In the multi-level analysis, pain at rest (OR 2.14; 95% confidence interval [CI] 1.39-3.30), movement (OR 1.30; 95% CI 0.66-2.56), pain categorised as 'severe' (OR 3.42; 95% CI 2.09-5.59) and increased pain severity when measured continuously (SMD 0.33; 95% CI 0.08-0.59) were associated with an increased delirium risk. There was substantial heterogeneity in both categorical (I2 = 0%-77%) and continuous analyses (I2 = 85%).

CONCLUSION

An increase in pain was associated with a higher risk of developing delirium. Adequate pain management with appropriate analgesia may reduce incidence and severity of delirium.

Costs of Care for Operative and Nonoperative Management of Emergency General Surgery Conditions

OBJECTIVE

Many emergency general surgery (EGS) conditions can be managed operatively or nonoperatively, with outcomes that vary by diagnosis. We hypothesized that operative management would lead to higher in-hospital costs but to cost savings over time.

BACKGROUND

EGS conditions account for $28 billion in health care costs in the United States annually. Compared with scheduled surgery, patients who undergo emergency surgery are at increased risk of complications, readmissions, and death, with accompanying costs of care that are up to 50% higher than elective surgery. Our prior work demonstrated that operative management had variable impacts on clinical outcomes depending on the EGS condition.

METHODS

This was a nationwide, retrospective study using fee-for-service Medicare claims data. We included patients 65.5 years of age or older with a principal diagnosis for an EGS condition 7/1/2015-6/30/2018. EGS conditions were categorized as: colorectal, general abdominal, hepatopancreaticobiliary (HPB), intestinal obstruction, and upper gastrointestinal. We used near-far matching with a preference-based instrumental variable to adjust for confounding and selection bias. Outcomes included Medicare payments for the index hospitalization and at 30, 90, and 180 days.

RESULTS

Of 507,677 patients, 30.6% received an operation. For HPB conditions, costs for operative management were initially higher but became equivalent at 90 and 180 days. For all others, operative management was associated with higher inpatient costs, which persisted, though narrowed, over time. Out-of-pocket costs were nearly equivalent for operative and nonoperative management.

CONCLUSIONS

Compared with nonoperative management, costs were higher or equivalent for operative management of EGS conditions through 180 days, which could impact decision-making for clinicians, patients, and health systems in situations where clinical outcomes are similar.

Association of Postoperative Delirium With Incident Dementia and Graft Outcomes Among Kidney Transplant Recipients

BACKGROUND

Kidney transplant (KT) recipients have numerous risk factors for delirium, including those shared with the general surgical population (eg, age and major surgery) and transplant-specific factors (eg, neurotoxic immunosuppression medications). Evidence has linked delirium to long-term dementia risk in older adults undergoing major surgery. We sought to characterize dementia risk associated with post-KT delirium.

METHODS

Using the United States Renal Data System datasets, we identified 35 800 adult first-time KT recipients ≥55 y. We evaluated risk factors for delirium using logistic regression. We evaluated the association between delirium and incident dementia (overall and by subtype: Alzheimer's, vascular, and other/mixed-type), graft loss, and death using Fine and Gray's subhazards models and Cox regression.

RESULTS

During the KT hospitalization, 0.9% of recipients were diagnosed with delirium. Delirium risk factors included age (OR = 1.40, 95% CI, 1.28-1.52) and diabetes (OR = 1.38, 95% CI, 1.10-1.73). Delirium was associated with higher risk of death-censored graft loss (aHR = 1.52, 95% CI, 1.12-2.05) and all-cause mortality (aHR = 1.53, 95% CI, 1.25-1.89) at 5 y post-KT. Delirium was also associated with higher risk of dementia (adjusted subhazard ratio [aSHR] = 4.59, 95% CI, 3.48-6.06), particularly vascular dementia (aSHR = 2.51, 95% CI, 1.01-6.25) and other/mixed-type dementia (aSHR = 5.58, 95% CI, 4.24-7.62) subtypes. The risk of all-type dementia associated with delirium was higher for younger recipients aged between 55 and 64 y ( Pinteraction  = 0.01).

CONCLUSIONS

Delirium is a strong risk factor for subsequent diagnosis of dementia among KT recipients, particularly those aged between 55 and 64 y at the time of transplant. Patients experiencing posttransplant delirium might benefit from early interventions to enhance cognitive health and surveillance for cognitive impairment to enable early referral for dementia care.

Patients' frailty and co-morbidities do not affect short-term mortality following emergency colorectal cancer surgery

AIM

To investigate the effects of frailty and co-morbidities on short and medium-term outcome following emergency colorectal cancer surgery.

METHODS

Data of patients who underwent emergency colorectal cancer operations between January 2013 and December 2016 were reviewed retrospectively. Collected data included demographic and operative variables, clinical frailty scale (CFS), Charlson comorbidity index (CCI) and cause of death with minimum 3 years follow-up.

RESULTS

Three-hundred and six patients (median age 72, range 18-100 years) underwent emergency colorectal cancer surgery; Some 74 (24.2%) patients had metastatic cancer at the time of emergency surgery, 77 (25.2%) were frail (CFS ≥4), while 118 (38.6%) were comorbid (CCI of ≥8). Thirty-day mortality was 4.2% (13 patients) and a further 12 patients died within 90 days (8.2%). By 1 year 73 (23.9%) patients had died, and by 3 years 151 (49.3%) patients died. Frailty did not impact 30-day mortality (6.5% vs 3.5%, p = 0.26) but frail patients (CFS ≥4) had a higher mortality rate at 90 days (16.9% vs 5.2%, p < 0.05), 1 year (37.7% vs 19.2%, p < 0.05) and 3 years (61.0% vs 45.4%, p < 0.05). Similarly, higher comorbidity (CCI ≥8) did not impact 30-day mortality (5.9% vs 3.2%, p = 0.25), but they had a higher mortality rate at 90 days (14.4% vs 4.3%, p < 0.05), 1 year (40.7% vs 13.3%, p < 0.05), and 3 years (76.3% vs 32.4%, p < 0.05).

CONCLUSION

Thirty-day mortality after emergency colorectal cancer surgery in frail and comorbid patients are similar to that of the general population.

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

BACKGROUND

We 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 METHODS

This 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.

RESULTS

The 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).

CONCLUSION

A single pre-anesthetic bolus of dexmedetomidine is a practical choice for preventing postoperative delirium in elderly patients undergoing emergency surgery.

TRIAL REGISTRATION

This 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).

Association between postoperative delirium and adverse outcomes in older surgical patients: A systematic review and meta-analysis

STUDY OBJECTIVE

To assess the incidence of postoperative delirium and its outcomes in older non-cardiac surgical patients.

DESIGN

A systematic review and meta-analysis with multiple databases searched from inception to February 22, 2022.

SETTING

Postoperative assessments.

PATIENTS

Non-cardiac and non-neurological surgical patients aged ≥60 years with and without postoperative delirium. Included studies must report ≥1 postoperative outcome. Studies with a small sample size (N < 100 subjects) were excluded.

MEASUREMENTS

Outcomes comprised the pooled incidence of postoperative delirium and its postoperative outcomes, including mortality, complications, unplanned intensive care unit admissions, length of stay, and non-home discharge. For dichotomous and continuous outcomes, OR and difference in means were computed, respectively, with a 95% CI.

MAIN RESULTS

Fifty-four studies (20,988 patients, 31 elective studies, 23 emergency studies) were included. The pooled incidence of postoperative delirium was 19% (95% CI: 16%, 23%) after elective surgery and 32% (95% CI: 25%, 39%) after emergency surgery. In elective surgery, postoperative delirium was associated with increased mortality at 1-month (OR: 6.60; 95% CI: 1.58, 27.66), 6-month (OR: 5.69; 95% CI: 2.33, 13.88), and 1-year (OR: 2.87; 95% CI: 1.63, 5.06). The odds of postoperative complications, unplanned intensive care unit admissions, prolonged length of hospital stay, and non-home discharge were also higher in delirium cases. In emergency surgery, patients with postoperative delirium had greater odds of mortality at 1-month (OR: 3.56; 95% CI: 1.77, 7.15), 6-month (OR: 2.60; 95% CI: 1.88, 3.61), and 1-year (OR: 2.30; 95% CI: 1.77, 3.00).

CONCLUSIONS

Postoperative delirium was associated with higher odds of mortality, postoperative complications, unplanned intensive care unit admissions, length of hospital stay, and non-home discharge. Prevention and perioperative management of delirium may optimize surgical outcomes.

Effect of postoperative delirium after cardiovascular surgery on 5-year mortality

INTRODUCTION

Postoperative delirium is a common complication after cardiovascular surgery. A meta-analysis revealed that postoperative delirium was associated with cognitive decline and dementia, which may affect long-term mortality. However, few studies have reported the association between postoperative delirium after cardiovascular surgery and long-term postoperative mortality. Therefore, we investigated the effect of postoperative delirium on 5-year survival rates of patients who underwent cardiovascular surgery.

METHODS

We retrospectively reviewed the records of patients who underwent cardiovascular surgery with cardiopulmonary bypass from January 2016 to December 2019. Postoperative delirium was defined as an Intensive Care Delirium Screening score ≥ 3, which might include subclinical delirium. Cox proportional hazards modeling was performed to assess the association between postoperative delirium and mortality. Postoperative mortality in patients with and without delirium was assessed using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Postoperative delirium was observed in 562 (31.9%) of 1731 patients. There were more elderly patients, more emergent surgery procedures, longer operative time, and larger transfusion volume in the postoperative delirium group. Cox regression analyses showed that delirium (hazard ratio (HR), 1.501; 95% confidence interval (CI), 1.053-2.140; p = 0.025) and emergent surgery (HR, 3.380; 95% CI, 2.231-5.122; p < 0.001) are significantly associated with 5-year mortality. Among patients who underwent elective surgery, postoperative delirium (HR, 1.987; 95% CI, 1.135-3.481; p = 0.016) is significantly associated with 5-year mortality. Kaplan-Meier survival analysis revealed that patients with postoperative delirium had significantly higher 5-year mortality.

CONCLUSIONS

Patients with postoperative delirium after cardiovascular surgery have significantly higher 5-year mortality.

Incidence change of postoperative delirium after implementation of processed electroencephalography monitoring during surgery: a retrospective evaluation study

BACKGROUND

Postoperative delirium (POD) is a common complication in the elderly, which is associated with poor outcomes after surgery. Recognized as predisposing factors for POD, anesthetic exposure and burst suppression during general anesthesia can be minimized with intraoperative processed electroencephalography (pEEG) monitoring. In this study, we aimed to evaluate whether implementation of intraoperative pEEG-guided anesthesia is associated with incidence change of POD.

METHODS

In this retrospective evaluation study, we analyzed intravenous patient-controlled analgesia (IVPCA) dataset from 2013 to 2017. There were 7425 patients using IVPCA after a noncardiac procedure under general anesthesia. Patients incapable of operating the device independently, such as cognitive dysfunction or prolonged sedation, were declined and not involved in the dataset. After excluding patients who opted out within three days (N = 110) and those with missing data (N = 24), 7318 eligible participants were enrolled. Intraoperative pEEG has been implemented since July 2015. Participants having surgery after this time point had intraoperative pEEG applied before induction until full recovery. All related staff had been trained in the application of pEEG-guided anesthesia and the assessment of POD. Patients were screened twice daily for POD within 3 days after surgery by staff in the pain management team. In the first part of this study, we compared the incidence of POD and its trend from 2013 January-2015 July with 2015 July-2017 December. In the second part, we estimated odds ratios of risk factors for POD using multivariable logistic regression in case-control setting.

RESULTS

The incidence of POD decreased from 1.18 to 0.41% after the administration of intraoperative pEEG. For the age group ≧ 75 years, POD incidence decreased from 5.1 to 1.56%. Further analysis showed that patients with pEEG-guided anesthesia were associated with a lower odd of POD (aOR 0.33; 95% CI 0.18-0.60) than those without after adjusting for other covariates.

CONCLUSIONS

Implementation of intraoperative pEEG was associated with a lower incidence of POD within 3 days after surgery, particularly in the elderly. Intraoperative pEEG might be reasonably considered as part of the strategy to prevent POD in the elder population.

TRIAL REGISTRATION

Not applicable.

Neurological complications in patients undergoing general surgery: A literature review

Surgical procedures are extremely burdensome for patients, as in addition to complications directly related to the intervention, they expose the patient to further complications resulting from the disturbance of key functions of homeostasis in the body's systems, particularly the circulatory, respiratory, and nervous systems. Furthermore, they may contribute to the exacerbation of symptoms of underlying chronic diseases. This paper focuses on the most common possible neurological complications that may occur after surgical procedures and includes topics such as stroke, chronic pain, neuropathy, and delirium. The risk factors for neurological deficits, their known or possible etiology, the most characteristic symptoms, and potential preventive actions are discussed. The paper analyzes articles from the PubMed, ResearchGate, and Scopus databases. A surge0on's knowledge of possible complications that may occur in the perioperative period enables early recognition and effective reduction of their negative impact on the patient's functioning and quality of life after surgery, contributing to better overall treatment outcomes.

Consensus Guidelines for Perioperative Care for Emergency Laparotomy Enhanced Recovery After Surgery (ERAS®) Society Recommendations Part 2-Emergency Laparotomy: Intra- and Postoperative Care

BACKGROUND

This is Part 2 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy (EL) using an Enhanced Recovery After Surgery (ERAS) approach. This paper addresses intra- and postoperative aspects of care.

METHODS

Experts in aspects of management of high-risk and emergency general surgical patients were invited to contribute by the International ERAS^® Society. PubMed, Cochrane, Embase, and Medline database searches were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses, and large cohort studies and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. Some ERAS^® components covered in other guideline papers are outlined only briefly, with the bulk of the text focusing on key areas pertaining specifically to EL.

RESULTS

Twenty-three components of intraoperative and postoperative care were defined. Consensus was reached after three rounds of a modified Delphi Process.

CONCLUSIONS

These guidelines are based on best available evidence for an ERAS^® approach to patients undergoing EL. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

LINKING EVIDENCE TO ACTION

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.

Developing and validating a machine learning ensemble model to predict postoperative delirium in a cohort of high-risk surgical patients: A secondary cohort analysis

BACKGROUND

Postoperative delirium (POD) has a negative impact on prognosis, length of stay and the burden of care. Although its prediction and identification may improve postoperative care, this need is largely unmet in the Brazilian public health system.

OBJECTIVE

To develop and validate a machine-learning prediction model and estimate the incidence of delirium. We hypothesised that an ensemble machine-learning prediction model that incorporates predisposing and precipitating features could accurately predict POD.

DESIGN

A secondary analysis nested in a cohort of high-risk surgical patients.

SETTING

An 800-bed, quaternary university-affiliated teaching hospital in Southern Brazil. We included patients operated on from September 2015 to February 2020.

PATIENTS

We recruited 1453 inpatients with an all-cause postoperative 30-day mortality risk greater than 5% assessed preoperatively by the ExCare Model.

MAIN OUTCOME MEASURE

The incidence of POD classified by the Confusion Assessment Method, up to 7 days postoperatively. Predictive model performance with different feature scenarios were compared with the area under the receiver operating characteristic curve.

RESULTS

The cumulative incidence of delirium was 117, giving an absolute risk of 8.05/100 patients. We developed multiple machine-learning nested cross-validated ensemble models. We selected features through partial dependence plot analysis and theoretical framework. We treated the class imbalance with undersampling. Different feature scenarios included: 52 preoperative, 60 postoperative and only three features (age, preoperative length of stay and the number of postoperative complications). The mean areas (95% confidence interval) under the curve ranged from 0.61 (0.59 to 0.63) to 0.74 (0.73 to 0.75).

CONCLUSION

A predictive model composed of three indicative readily available features performed better than those with numerous perioperative features, pointing to its feasibility as a prognostic tool for POD. Further research is required to test the generalisability of this model.

TRIAL REGISTRATION

Institutional Review Board Registration number 04448018.8.0000.5327 (Brazilian CEP/CONEP System, available in https://plataformabrasil.saude.gov.br/ ).

Association of intraoperative hypotension and severe postoperative complications during non-cardiac surgery in adult patients: A systematic review and meta-analysis

Background

Intraoperative hypotension (IOH) is a common side effect of non-cardiac surgery that might induce poor postoperative outcomes. The relationship between the IOH and severe postoperative complications is still unclear. Thus, we summarized the existing literature to evaluate whether IOH contributes to developing severe postoperative complications during non-cardiac surgery.

Methods

We conducted a comprehensive search of PubMed, Embase, Cochrane Library, Web of Science, and the CBM from inception to 15 September 2022. The primary outcomes were 30-day mortality, acute kidney injury (AKI), major adverse cardiac events (myocardial injury or myocardial infarction), postoperative cognitive dysfunction (POCD), and postoperative delirium (POD). Secondary outcomes included surgical-site infection (SSI), stroke, and 1-year mortality.

Results

72 studies (3 randomized; 69 non-randomized) were included in this study. Low-quality evidence showed IOH resulted in an increased risk of 30-day mortality (OR, 1.85; 95% CI, 1.30-2.64; P < .001), AKI (OR, 2.69; 95% CI, 2.15-3.37; P < .001), and stroke (OR, 1.33; 95% CI, 1.21-1.46; P < .001) after non-cardiac surgery than non-IOH. Very low-quality evidence showed IOH was associated with a higher risk of myocardial injury (OR, 2.00; 95% CI, 1.17-3.43; P = .01), myocardial infarction (OR, 2.11; 95% CI, 1.41-3.16; P < .001), and POD (OR, 2.27; 95% CI, 1.53-3.38; P < .001). Very low-quality evidence showed IOH have a similar incidence of POCD (OR, 2.82; 95% CI, 0.83-9.50; P = .10) and 1-year-mortality (OR, 1.66; 95% CI, 0.65-4.20; P = .29) compared with non-IOH in non-cardiac surgery.

Conclusion

Our results suggest IOH was associated with an increased risk of severe postoperative complications after non-cardiac surgery than non-IOH. IOH is a potentially avoidable hazard that should be closely monitored during non-cardiac surgery.

Early prediction of delirium upon intensive care unit admission: Model development, validation, and deployment

STUDY OBJECTIVE

To develop, validate, and deploy models for predicting delirium in critically ill adult patients as early as upon intensive care unit (ICU) admission.

DESIGN

Retrospective cohort study.

SETTING

Single university teaching hospital in Taipei, Taiwan.

PATIENTS

6238 critically ill patients from August 2020 to August 2021.

MEASUREMENTS

Data were extracted, pre-processed, and split into training and testing datasets based on the time period. Eligible variables included demographic characteristics, Glasgow Coma Scale, vital signs parameters, treatments, and laboratory data. The predicted outcome was delirium, defined as any positive result (a score ≥ 4) of the Intensive Care Delirium Screening Checklist that was assessed by primary care nurses in each 8-h shift within 48 h after ICU admission. We trained models to predict delirium upon ICU admission (ADM) and at 24 h (24H) after ICU admission by using logistic regression (LR), gradient boosted trees (GBT), and deep learning (DL) algorithms and compared the models' performance.

MAIN RESULTS

Eight features were extracted from the eligible features to train the ADM models, including age, body mass index, medical history of dementia, postoperative intensive monitoring, elective surgery, pre-ICU hospital stays, and GCS score and initial respiratory rate upon ICU admission. In the ADM testing dataset, the incidence of ICU delirium occurred within 24 h and 48 h was 32.9% and 36.2%, respectively. The area under the receiver operating characteristic curve (AUROC) (0.858, 95% CI 0.835-0.879) and area under the precision-recall curve (AUPRC) (0.814, 95% CI 0.780-0.844) for the ADM GBT model were the highest. The Brier scores of the ADM LR, GBT, and DL models were 0.149, 0.140, and 0.145, respectively. The AUROC (0.931, 95% CI 0.911-0.949) was the highest for the 24H DL model and the AUPRC (0.842, 95% CI 0.792-0.886) was the highest for the 24H LR model.

CONCLUSION

Our early prediction models based on data obtained upon ICU admission could achieve good performance in predicting delirium occurred within 48 h after ICU admission. Our 24-h models can improve delirium prediction for patients discharged >1 day after ICU admission.

Delirium Prevention and Management in Frail Surgical Patients

Delirium, an acute, fluctuating impairment in cognition and awareness, is one of the most common causes of postoperative brain dysfunction. It is associated with increased hospital length of stay, health care costs, and mortality. There is no FDA-approved treatment of delirium, and management relies on symptomatic control. Several preventative techniques have been proposed, including the choice of anesthetic agent, preoperative testing, and intraoperative monitoring. Frailty, a state of increased vulnerability to adverse events, is an independent and potentially modifiable risk factor for the development of delirium. Diligent preoperative screening techniques and implementation of prevention strategies could help improve outcomes in high-risk patients.

Apolipoprotein E4 allele is genetically associated with risk of the short- and medium-term postoperative cognitive dysfunction: A meta-analysis and trial sequential analysis

The aim of systematic review and meta-analysis was to investigate whether APOE4 was associated with postoperative neurologic dysfunction occurrence in short- or medium-term among surgical patients and to study the potential genetic association among these two entities. We searched electronic databases for reserch studies to evaluate the association of APOE4 with postoperative delirium (POD) or short- and medium term postoperative cognitive dysfunction (POCD). Twenty-two trials (16 prospective and six retrospective) with 6734 patients were included. APOE4 alleles was shown significantly associated with POCD within 1 week (odds ratio, OR, 1.89, 95% confidence interval, CI, 1.36 to 2.6278, p < 0.01) in the random-effects model. A significant association was also noted between APOE4 and POCD in medium-term, 1-3 months, after surgery (OR: 1.67, 95% CI: 1.003-2.839, p = 0.049). However, APOE4 was not significantly associated with POCD 1 year after surgery (OR: 0.98, 95% CI: 0.57-1.70, p = 0.9449) and POD (OR: 1.28, 95% CI: 0.85-1.91, p = 0.23). In conclusion, APOE4 alleles was genetically associated with short- and medium-term postoperative neurological dysfunction and future screening or preventive strategies derived is highly potential to improve outcomes.

Non-pharmacological prevention of postoperative delirium by occupational therapy teams: A randomized clinical trial

Background

Patients who develop postoperative delirium (POD) have several clinical complications, such as increased morbidity, increased hospital stays, higher hospital costs, cognitive and functional impairment, and higher mortality. POD is a clinical condition preventable by standard non-pharmacological measures An intensive Occupational Therapy (OT) intervention has been shown to be highly effective in preventing delirium in critically ill medical patients, but it is unknown the effect in surgical patients. Thus, we designed a prospective clinical study with the aim to determine whether patients undergoing intervention by the OT team have a lower incidence of POD compared to the group treated only with standard measures.

Methods

A multicenter, single-blind, randomized clinical trial was conducted between October 2018 and April 2021, in Santiago of Chile, at a university hospital and at a public hospital. Patients older than 75 years undergoing elective major surgery were eligible for the trial inclusion. Patients with cognitive impairment, severe communication disorder and cultural language limitation, delirium at admission or before surgery, and enrolled in another study were excluded. The intervention consisted of OT therapy twice a day plus standard internationally recommended non-pharmacological prevention intervention during 5 days after surgery. Our primary outcome was development of delirium and postoperative subsyndromal delirium.

Results

In total 160 patients were studied. In the interventional group, treated with an intensive prevention by OT, nine patients (12.9%) developed delirium after surgery and in the control group four patients (5.5%) [p = 0.125, RR 2.34 CI 95 (0.75-7.27)]. Whereas subsyndromal POD was present in 38 patients in the control group (52.1%) and in 34 (48.6%) in the intervention group [p = 0.4, RR 0.93 CI95 (0.67-1.29)]. A post hoc analysis determined that the patient's comorbidity and cognitive status prior to hospitalization were the main risk factors to develop delirium after surgery.

Discussion

Patients undergoing intervention by the OT team did not have a lower incidence of POD compared to the group treated only with standard non-pharmacological measures in adults older than 75 years who went for major surgery.

Clinical trial registration

www.ClinicalTrials.gov, identifier NCT03704090.

Intraoperative infusion of dexmedetomidine for prevention of postoperative delirium in elderly patients undergoing craniotomy: a protocol of randomised clinical trial

INTRODUCTION

Postoperative delirium (POD) is a common surgical complication. The incidence is 19% in neurological procedures, and advanced age is a risk factor for neurological procedures. Many studies have shown that dexmedetomidine (DEX) reduced the incidence of delirium after non-cardiac surgery in elderly patients. However, there are few studies focus on the effect of DEX on POD in elderly patients undergoing neurosurgery.

METHODS AND ANALYSIS

This is a randomised, double-blinded, paralleled-group and controlled trial. Patients older than 65 years and scheduled for elective craniotomy will be randomly assigned to the DEX group and the control group. After endotracheal intubation, patients in the DEX group will be administered with continuous DEX infusion at rate of 0.4 µg/kg/hour until the surgical haemostasis. In the control group, patients will receive the identical volume of normal saline in the same setting. The primary outcome is the incidence of POD during the first 5 days. Delirium will be evaluated through a combination of three methods, including the Richmond Agitation Sedation Scale (RASS), the confusion assessment method for ICU (CAM-ICU) and the 3 min diagnostic interview for CAM (3D-CAM). The RASS, CAM-ICU and 3D-CAM will be evaluated two times per day (08:00-10:00 and 18:00-20:00 hours) during the first postoperative 5 days. Secondary outcomes include pain severity score, quality of recovery, quality of sleep, cognitive function, psychological health state, intraoperative data, physiological status, length of stay in ICU and hospital, hospitalisation costs, non-delirium complications, and 30-day all-cause mortality.

ETHICS AND DISSEMINATION

The protocol (V.4.0) has been approved by the medical ethics committee of Beijing Tiantan Hospital, Capital Medical University (KY2021-194-03). The findings of the study will be disseminated in a peer-reviewed journal and at a scientific conference.

TRIAL REGISTRATION NUMBER

NCT05168280.

Effect of the using a pupillometer on recovery and early cognitive functions in anesthesia management for endoscopic retrograde cholangiopancreaticography in geriatric patients

Background/Aim: Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive procedure used for the diagnosis and treatment of pancreaticobiliary pathologies. Because it is an invasive procedure that is difficult to tolerate by the patient and takes a long time, it is preferable to use it under deep patient sedation and even under general anesthesia in some cases. This study aimed to evaluate the effects of using a pupillometer versus the Ramsey sedation scale (RSS) during anesthesia management for ERCP on recovery and return of cognitive functions in the geriatric patient population. Methods: A mini-mental test was applied to evaluate the pre-operative cognitive functions of the cases before the intervention. The included patients were divided into groups using the sealed-envelope method. Management of the depth of anesthesia was evaluated by Ramsey sedation scale; in group R and was evaluated by pupillometer in group P. The infusion dose of dexmedetomidine was changed to 0.1 µg/kg/h according to the results of the evaluation. Results: Sixty cases were included in the study. No difference between the groups in terms of age (P=0.246), gender (P=0.797), American Society of Anesthesiologists (ASA) score (P=0.197), comorbidity (P=0.748), anesthesia duration (P=0.397), midazolam doses (P=0.561), propofol doses (P=0.677), and intra-operative hemodynamic values (P=0.668) were found. Intra-operative dexmedetomidine dose was statistically significantly lower (P=0.004), and recovery was faster in group P (P<0.001). While no differences between the groups in the pre-operative mini-mental test scores (P=0.140) were found, the post-operative scores were statistically significantly lower in group R (P=0.025). Conclusion: In this study, it was observed that the pupillometer led to a reduction in the use of dexmedetomidine and cognitive functions were better during the post-operative recovery period. As a result, depth of anesthesia can be monitored with a pupillometer. Although the use of pupillometer in endoscopic interventions in the geriatric patient group does not make a hemodynamic difference when compared with the RSS, the pupillometer leads to accelerated recovery from anesthesia, improvement in the return of cognitive functions, and reduction in drug consumption.

Occurrence of Postoperative Delirium and the Use of Different Assessment Tools

(1) Background: Postoperative delirium (POD) poses a high risk of worsening outcomes for patients and is also a burden for hospitals. The leading guidelines recommend standardized POD assessment and prevention. The aim of this subgroup analysis of the PRe-Operative Prediction of Postoperative DElirium by Appropriate SCreening (PROPDESC) trial was to compare different delirium assessments and to analyse the frequency of POD on five postoperative days. (2) Methods: This prospective observational trial enrolled 1097 patients in a university hospital from 2018 until 2019. The following POD assessment tools were used for five consecutive days: Confusion Assessment Method for ICU (CAM-ICU) or Confusion Assessment Method for normal ward (CAM), 4 A's Test (4AT) and Delirium Observation Screening (DOS) scale. (3) Results: In a 5-day visit interval, most new POD developments occurred on the first and second postoperative day. A clear recommendation for a specific POD assessment tool based on our results cannot be given. (4) Conclusions: According to guidelines, a POD assessment should take place on the first five postoperative days, but of these, the first two are those of highest POD occurrence. The POD assessment tool used should at best include direct patient questioning and aspects of patient observation.

Predisposing and Precipitating Factors Associated With Delirium: A Systematic Review

IMPORTANCE

Despite discrete etiologies leading to delirium, it is treated as a common end point in hospital and in clinical trials, and delirium research may be hampered by the attempt to treat all instances of delirium similarly, leaving delirium management as an unmet need. An individualized approach based on unique patterns of delirium pathophysiology, as reflected in predisposing factors and precipitants, may be necessary, but there exists no accepted method of grouping delirium into distinct etiologic subgroups.

OBJECTIVE

To conduct a systematic review to identify potential predisposing and precipitating factors associated with delirium in adult patients agnostic to setting.

EVIDENCE REVIEW

A literature search was performed of PubMed, Embase, Web of Science, and PsycINFO from database inception to December 2021 using search Medical Subject Headings (MeSH) terms consciousness disorders, confusion, causality, and disease susceptibility, with constraints of cohort or case-control studies. Two reviewers selected studies that met the following criteria for inclusion: published in English, prospective cohort or case-control study, at least 50 participants, delirium assessment in person by a physician or trained research personnel using a reference standard, and results including a multivariable model to identify independent factors associated with delirium.

FINDINGS

A total of 315 studies were included with a mean (SD) Newcastle-Ottawa Scale score of 8.3 (0.8) out of 9. Across 101 144 patients (50 006 [50.0%] male and 49 766 [49.1%] female patients) represented (24 015 with delirium), studies reported 33 predisposing and 112 precipitating factors associated with delirium. There was a diversity of factors associated with delirium, with substantial physiological heterogeneity.

CONCLUSIONS AND RELEVANCE

In this systematic review, a comprehensive list of potential predisposing and precipitating factors associated with delirium was found across all clinical settings. These findings may be used to inform more precise study of delirium's heterogeneous pathophysiology and treatment.

Postoperative delirium in older patients after undergoing pelvic organ prolapse surgery

INTRODUCTION AND HYPOTHESIS

To determine the 7-day incidence and risk factors of postoperative delirium (POD) occurring after prolapse surgery in women aged ≥60 years.

METHODS

A prospective study of women ≥60 years undergoing prolapse surgery at a large academic center. The primary outcome is positive Confusion Assessment Method delirium screen administered in person or by telephone at the time of hospital discharge and postoperative days 1, 3, 5, and 7.

RESULTS

This analysis included 165 patients, mean ± SD age of 72.5 ± 6.1 years, with median (IQR) years of education of 13 (12-16), and baseline Modified Mini-Mental Status (3MS) Exam score of 95 (92-98). Prolapse repair type was vaginal for 70% (n=115) and laparoscopic for 30% (n=50) of patients; most under general anesthesia, 151 (92.1%). The incidence of positive delirium screen during the first week after surgery was 12.1% (n=20). Most of these participants screened positive on postoperative day 0, 8.4% (n=14). In univariate analyses, a positive screen was associated with older age and fewer education years, lower 3MS exam score, greater baseline geriatric depression scale score, and greater frailty score. Lower 3MS score was the only variable that remained significant in the final model (adjusted odds ratio 0.84, 95% CI 0.75-0.95).

CONCLUSIONS

One in 12 women ≥60 years deemed eligible for discharge on the day of prolapse surgery screens positive for delirium. The 7-day POD incidence is comparable to other elective non-cardiac surgery cohorts. Given the increasing trend toward same day discharge after major prolapse surgery, more research is needed to determine the impact of universal delirium screening as part of discharge assessments.

Anesthetic Practice Trends and Perceptions Toward Postoperative Delirium: A Mixed-Methods Analysis

BACKGROUND

Delirium is the most common postoperative complication in older adults, though anesthesiologist awareness of delirium prevention guidelines-and associated practice trends-remains unknown.

METHODS

This was a convergent mixed-methods study, which simultaneously analyzed quantitative and qualitative data to determine delirium guideline awareness among anesthesiologists and practice patterns based on guideline recommendations. Quantitative data were abstracted from the Multicenter Perioperative Outcomes Group database for noncardiac surgery patients (2009-2020) aged 65 years and older. Linear trends were reported for select guideline-based delirium prevention recommendations via regression modeling. Anesthesiologists (n = 40) from a major academic center without a structured delirium reduction program on hospital wards were then surveyed regarding knowledge and practices with respect to postoperative delirium. For qualitative data, 3 focus groups were held to further discuss guideline awareness and identify challenges with delirium prevention.

RESULTS

Quantitative results demonstrated a significant decline in the proportion of cases with midazolam between 2009 and 2020, with the largest decrease observed with urologic surgeries (-3.9%/y; 95% confidence interval [CI], -4.2 to -3.6; P < .001). Use of regional anesthesia increased over this period, particularly with gynecologic surgeries (+2.3%/y; 95% CI, 1.2-3.4; P = .001). Anesthesiologist survey results revealed variable guideline awareness, as 21 of 39 (54%) respondents reported being aware of guidelines for anesthetic management of older adults. Importantly, unawareness of delirium management guidelines was the most frequently cited challenge (17 of 37, 46%) when caring for older adults. Finally, focus group participants were largely unaware of postoperative delirium guidelines. However, participants conveyed key barriers to delirium identification and prevention, including the unclear pathophysiology, nonmodifiable risk factors, and system-based hospital challenges. Participants also expressed a desire for decision-support systems, integrated within the perioperative workflow, that provide evidence-based recommendations for reducing delirium risk.

CONCLUSIONS

Perioperative practice trends are indicative of an improving environment for postoperative delirium. However, delirium guideline awareness remains variable among anesthesiologists, and key barriers continue to exist for identifying and preventing postoperative delirium.

Postoperative delirium in geriatric patients with hip fractures

Postoperative delirium (POD) is a frequent complication in geriatric patients with hip fractures, which is linked to poorer functional recovery, longer hospital stays, and higher short-and long-term mortality. Patients with increased age, preoperative cognitive impairment, comorbidities, perioperative polypharmacy, and delayed surgery are more prone to develop POD after hip fracture surgery. In this narrative review, we outlined the latest findings on postoperative delirium in geriatric patients with hip fractures, focusing on its pathophysiology, diagnosis, prevention, and treatment. Perioperative risk prediction, avoidance of certain medications, and orthogeriatric comprehensive care are all examples of effective interventions. Choices of anesthesia technique may not be associated with a significant difference in the incidence of postoperative delirium in geriatric patients with hip fractures. There are few pharmaceutical measures available for POD treatment. Dexmedetomidine and multimodal analgesia may be effective for managing postoperative delirium, and adverse complications should be considered when using antipsychotics. In conclusion, perioperative risk intervention based on orthogeriatric comprehensive care is the most effective strategy for preventing postoperative delirium in geriatric patients with hip fractures.

Polypharmacy is predictive of postoperative complications in older adults undergoing ventral hernia repair

BACKGROUND

Ventral hernias are common in older adults, and may be repaired via a transversus abdominus release (TAR). Older adults undergoing surgery have unique age-related risk factors, including polypharmacy. Polypharmacy is highly prevalent in older adults and is associated with adverse postoperative outcomes. Our aim was to examine the prevalence and association of polypharmacy with clinical outcomes in older adults undergoing a TAR.

METHODS

Patients 60 years and older who underwent elective open or robotic bilateral TAR were included in the study. Average daily medications taken preoperatively was collected and stratified by tertiles. Baseline demographic data, peri- and postoperative outcomes, and 30-day outcomes were collected.

RESULTS

There were 132 total patients with an average age of 67.8 years. The number of daily medications ranged from 0 to 28, with an overall mean of 11.2 medications. Patients in tertile 1 took an average of 5.3 medications, tertile 2 10.5 medications, and tertile 3 17.9 medications. Patients in tertile 3 had more than double the rate of in-hospital complications (0.7) compared to tertiles 1 and 2 (0.3 and 0.3, respectively; p = 0.03). A greater number of daily medications was independently associated with postoperative delirium [odds ratio (OR) 1.2, 95% confidence interval (CI) 1.0-1.3], cardiac events (OR 1.2, 95% CI 1.0-1.3), ICU stay (OR 1.2, 95% CI 1.0-1.3), and discharge to a skilled nursing facility (SNF) (OR 1.2, 95% CI 1.0-1.5).

CONCLUSIONS

Polypharmacy was very common in older adults undergoing a TAR, and was associated with in-hospital complications, postoperative delirium, cardiac events, ICU stay, length of stay, and discharge to a SNF. Additional study is needed to assess if preoperative interventions to limit polypharmacy will improve outcomes for older adults undergoing a TAR.

Risk factor stratification for postoperative delirium: A retrospective database study

METHODS

The EHR of 32734 patients >18 years of age undergoing surgery and had POD assessment were reviewed. Patient characteristics and study variables were summarized between delirium groups. We constructed univariate logistic regression models for POD using each study variable to estimate odds ratios (OR) and constructed a multivariable logistic regression model with stepwise variable selection. In order to create a clinically useful/implementable tool we created a nomogram to predict risk of delirium.

RESULTS

Overall, we found a rate of POD of 3.7% across our study population. The Model achieved an AUC of the ROC curve of 0.83 (95% CI 0.82-0.84). We found that age, increased American Society of Anesthesiologists (ASA) score (ASA 3-4 OR 2.81, CI 1.49-5.28, P < .001), depression (OR 1.28, CI 1.12-1.47, P < .001), postoperative benzodiazepine use (OR 3.52, CI 3.06-4.06, P < .001) and urgent cases (Urgent OR 3.51, CI 2.92-4.21, P < .001; Emergent OR 3.99, CI 3.21-4.96, P < .001; Critically Emergent OR 5.30, CI 3.53-7.96, P < .001) were associated with POD.

DISCUSSION

We were able to distinguish the contribution of individual risk factors to the development of POD. We created a clinically useful easy-to-use tool that has the potential to accurately identify those at high-risk of delirium, a first step to prevent POD.

The influence of orthopedic surgery on the incidence of post-operative delirium in geriatric patients: results of a prospective observational study

Background

Postoperative delirium (PD) is a major concern in geriatric patients undergoing orthopedic surgery. This prospective observational study aims to examine the incidence of PD, to identify intervention-specific risk factors and to investigate the influence of orthopedic surgery on delirium.

Methods

From 2019 to 2020, 132 patients ≥70 years of age with endoprosthetic (Group E) or spinal surgery (Group S) were included. Upon admission, the ISAR score, the Nursing Delirium Screening Scale, potential risk factors, the ASA score, duration of surgery, type of anesthesia, blood loss, and hemoglobin drop were recorded. For risk factor analysis patients were grouped into Group D (delirium) and Group ND (no delirium). Primary endpoint was the occurrence of PD.

Results

Of 132 patients, 50 were included in Group E and 82 in Group S. Mean age and ISAR score were not significantly different between groups. Delirium rate in Group E and S was 12% vs. 18% (p = 0.3). Differences could be observed between Group D and ND in duration of surgery (173 min vs. 112 min, p = 0.02), postoperative hemoglobin drop (3.2 g/dl vs. 2.3 g/dl; p = 0.026), history of PD (23% vs. 11%, p = 0.039) and use of isoflurane (6 vs. 2). Type of surgery was not an independent risk factor (p = 0.26).

Conclusion

Specific type of orthopedic surgery is not an independent risk factor for PD. Prevention of PD should focus on duration of surgery and blood loss, particularly in patients with a history of PD. A possible delirogenic potential of isoflurane should be further studied.

The Assessment of Immediate Postoperative Delirium in Neurologically Intact Adult Patients Admitted to the Post-anesthesia Care Unit: A Cross-Sectional Study

Background

Immediate postoperative delirium (IPD) in the post-anesthesia care unit (PACU) can cause significant morbidity affecting everyday activities and length of stay with cost implications. This study was undertaken to find the proportion of IPD in PACU and its association with anesthesia and other perioperative factors.

Methods

After obtaining ethical approval and informed consent, this cross-sectional study was conducted in the PACU. A total of 600 consecutive adult patients (American Society of Anesthesiologists (ASA) 1-3) posted for surgery were approached between January and March 2019, of which 402 patients without neurological diseases and language and hearing discrepancies were studied. All patients had the intervention of surgery under anesthesia in a usual manner. Delirium was assessed preoperatively, postoperatively at 15 and 30 minutes, and before discharge from the PACU. IPD was assessed using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) score, while sedation/agitation was assessed using the Richmond Agitation-Sedation Scale (RASS). The primary outcomes were the proportion of IPD, association with anesthesia, and perioperative risk factors. The secondary outcomes were the length of stay, delirium treatment, and mortality.

Results

Overall, the IPD proportion was 14.7%. A significant association was demonstrated with premedication with midazolam (odds ration (OR): 3.2; 95% confidence interval (CI): 1.42-7.35; P=0.003), general anesthesia (GA) (OR: 6.3; 95% CI: 2.23-17.8; P<0.001), duration of anesthesia (126 versus 95 minutes; P=0.001), laparoscopic mode of surgical access (OR: 3.4; 95% CI: 1.8-6.4; P<0.001), and postoperative RASS >/< 0 (OR: 10.6; 95% CI: 4.69-24.11; P<0.001) at 30 minutes and before discharge from the PACU. Multivariate analysis showed the strongest association of RASS at 30 minutes with IPD.

Conclusion

The proportion of IPD was found to be 14.7% in this study, and the chances of developing IPD are high if the patient is not awake and calm in the PACU, especially if midazolam is administered as premedication, followed by general anesthesia (GA) for a long duration.

Prevalence of Emergence Delirium and Associated Factors among Older Patients Who Underwent Elective Surgery: A Multicenter Observational Study

Background

Emergence delirium is a common and serious postoperative complication in older surgical patients. It occurs at any time in the perioperative period, during or immediately following emergence from general anesthesia. Unfortunately, it is highly associated with postoperative complications such as a decrease in functional capacity, prolonged hospital stay, an increase in health care costs, and morbidity and mortality. The goal of this study was to determine the prevalence of emergence delirium and associated factors among older patients who underwent elective surgery in the teaching hospitals of Ethiopia at the postanesthesia care unit in 2021.

Methods

A multicenter prospective observational study was conducted at the postanesthetic care unit in the four teaching hospitals of Ethiopia. Older surgical patients admitted to the postanesthesia care unit who underwent elective surgery in the four teaching hospitals of Ethiopia were selected by using simple random sampling. Pretested structured questionnaire was used to collect data. Data were entered into EpiData (version 4.6) and exported to the SPSS (version 25.0). Binary logistic regression was used to identify factors independently associated with the emergence delirium.

Results

Out of 384 older patients included in the study, the prevalence of emergence delirium was 27.6%. Preoperative low hemoglobin levels (AOR: 2.0, 95% CI; 1.77–3.46), opioid (AOR: 8.0, 95% CI; 3.22–27.8), anticholinergic premedications (AOR: 8.5, 95% CI; 6.85–17.35), and postoperative pain (AOR: 3.10, 95 CI; 2.07–9.84) at PACU were independently associated with emergence delirium.

Conclusion

The prevalence of emergence delirium was high among older patients who underwent elective surgery. Opioid and anticholinergic premedication, low preoperative hemoglobin, and the presence of postoperative pain were independently associated with the emergence delirium. Adequate preoperative optimization and postoperative analgesia may reduce the prevalence of emergence delirium.

Delirium in elderly postoperative patients: A prospective cohort study

AIM

To describe the incidence, time in days and risk factors for postoperative delirium in elderly patients.

DESIGN

Prospective cohort study.

METHODS

Patients over 65 years were daily screened with the 4A's Test and the Delirium Observation Screening Scale for postoperative delirium. A psychiatrist assessed according to the DSM-V. We performed descriptive and logistic regression analyses.

RESULTS

From 202 patients, 7.5% (N = 15) had a diagnosed postoperative delirium, whereby 73.3% (N = 11) developed the delirium during the first 48 hr after surgery. The median duration was 1 day. Patients over 80 years suffering from heart failure with surgical drains, bladder catheter, central venous catheter had higher odds for developing a postoperative delirium. The incidence of postoperative delirium in our sample was lower compared with other surgical and ortho-geriatric populations. Despite age, several modifiable postoperative factors were associated with the occurrence of postoperative delirium.

Outcomes in Post-operative Delirium Following Bowel Resection: A Single Center Retrospective Review

INTRODUCTION

Delirium is associated with adverse post-operative outcomes, long-term cognitive dysfunction, and prolonged hospitalization. Risk factors for its development include longer surgical duration, increased operative complexity and invasiveness, and medical comorbidities. This study aims to further evaluate the incidence of delirium and its impact on outcomes among patients undergoing both elective and emergency bowel resections.

METHODS

This is a retrospective cohort study using an institutional patient registry. All patients undergoing bowel resection over a 3.5-year period were included. The study measured the incidence of post-operative delirium via the nursing confusion assessment method. This incidence was then compared to patient age, emergency versus elective admission, length of stay, mortality, discharge disposition, and hospital cost.

RESULTS

A total of 1934 patients were included with an overall delirium incidence of 8.8%. Compared to patients without delirium, patients with delirium were more likely to have undergone emergency surgery, be greater than 70 y of age, have a longer length of stay, be discharged to a skilled nursing facility, and have a more expensive hospitalization. In addition, the overall mortality was 14% in patients experiencing delirium versus 0.1% in those that did not. Importantly, when broken down between elective and emergency groups, the mortality of those experiencing delirium was similar (11 versus 13%).

CONCLUSIONS

The development of delirium following bowel resection is an important risk factor for worsened outcomes and mortality. Although the incidence of delirium is higher in the emergency surgery population, the development of delirium in the elective population infers a similar risk of mortality.

Clinical Predictors and Outcomes Associated with Postoperative Delirium Following Infrainguinal Bypass Surgery

OBJECTIVES

Postoperative delirium (POD) is common yet often underdiagnosed following vascular surgery. Elderly patients with advanced peripheral artery disease may be at particular risk for POD yet understanding of the clinical predictors and impact of POD is incomplete. We sought to identify POD predictors and associated resource utilization after infrainguinal lower extremity bypass.

METHODS

This single center retrospective analysis included all infrainguinal bypass cases performed for peripheral arterial disease from 2012-2020. The primary outcome was inpatient post-operative delirium. Delirium sequelae were also evaluated. Key secondary outcomes were length of stay, non-home discharge, readmission, 30-day amputation, postoperative myocardial infarction, mortality, and 2-year survival. Regression analysis was used to evaluate risk factors for delirium in addition to association with 2-year survival and amputation free survival.

RESULTS

Among 420 subjects undergoing infrainguinal lower extremity bypass, 105 (25%) developed POD. Individuals with POD were older and more likely to have non-elective surgery (p<0.05). On multivariable analysis, independent predictors of POD were age 60-89 years old, chronic limb threatening ischemia, female sex, and non-elective procedure. Consultations for POD took place for 25 cases (24%); 13 (52%) were with pharmacists, and only 4 (16%) resulted in recommendations. The average length of stay for those with POD was higher (17 days vs 9 days; p<.001). POD was associated with increased non-home discharge (61.8% vs 22.1%; p<.001), 30-day major amputation (6.7% vs 1.6%; p<0.01), 30-day postoperative myocardial infarction (11.4% vs 4.1%; p<0.01), and 90-day mortality (7.6% vs 2.9%; p=0.03). Survival at 2 years was lower in those with delirium (89% vs 75%; p<.001). In a Cox proportional hazards model, delirium was independently associated with decreased survival (HR=2.0; 95% CI=1.15-3.38; p=0.014) and decreased major-amputation free survival (HR=1.9; 95% CI=1.18-2.96; p=0.007).

CONCLUSIONS

Postoperative delirium is common following infrainguinal lower extremity bypass and is associated with other adverse post-operative outcomes and increased resource utilization, including increased hospital length of stay, non-home discharge, and worse 2-year survival. Future studies should evaluate the role of routine multidisciplinary care for high-risk patients to improve perioperative outcomes for vulnerable older adults undergoing infrainguinal lower extremity bypass.

The predictors of postoperative delirium at surgical units in Sudan: A multicenter, cross-sectional, prospective study

Background

Knowledge of potential and amenable risk factors involved in the development of postoperative delirium (POD) is imperative for successful prevention and subsequent management.

Objective

The current study objective was to delineate the risk factors associated with the occurrence of POD among patients undergoing surgical procedures.

Methods

This multi-center (6 hospitals), cross-sectional prospective hospital-based study recruited 415 subjects aged ≥50 years who were scheduled to undergo different types of surgery. Delirium Observational Screening Scale used for the diagnosis of POD. Short Nutritional Assessment Questionnaire used for assessing the nutritional and the hydration status of patients. Pre and postoperative risk factors analyzed by univariate (chi square) and then multivariate analyses and the incidence rate of POD, was reported.

Results

The main outcome measure was the development of POD. Out of the 385, only 43 subjects (11.2%) developed POD. High American Society of Anesthesiologists score (OR: 10.76, 95% CI: 1.379-83.99, P =0.023), duration of surgery (OR: 5.426, 95% CI: [2.249-13.092]; P =0.0001), were the strongest independent risk factors for the development of POD. Katz Index of Independence in Activities of Daily Living score (OR: 3.227, 95% CI: [1.177-8.844], P =0.023), and age ≥ 70 years (OR: 1.174, 95% CI: [1.015-1.359]; P =0.027) were additional strongest independent risk factors for the development of POD.

Conclusion

Based on analysis or study, we found High American Society of Anesthesiologist sore, Katz-ADL, duration of surgery, and advanced age were predictors of POD. Our findings suggest preventive measures initiated in subjects identified at risk of developing POD. These results support the healthcare providers in the early prevention, diagnosis, and timely management of POD.

Impact of combined epidural anaesthesia/analgesia on postoperative cognitive impairment in patients receiving general anaesthesia: a meta-analysis of randomised controlled studies

BACKGROUND

To investigate the efficacy of combined epidural anaesthesia/analgesia (EAA) against postoperative delirium/cognitive dysfunction (POD/POCD) in adults after major non-cardiac surgery under general anaesthesia (GA).

METHODS

The databases of PubMed, Google scholar, Embase and Cochrane Central Register were searched from inception to November 2021 for available randomised controlled trials (RCTs) that assessed the impact of EAA on risk of POD/POCD. The primary outcome was risk of POD/POCD, while the secondary outcomes comprised postoperative pain score, length of hospital stay (LOS), risk of complications, and postoperative nausea/vomiting (PONV).

RESULTS

Meta-analysis of eight studies with a total of 2376 patients (EAA group: 1189 patients; non-EAA group: 1187 patients) revealed no difference in risk of POD/POCD between the EAA and the non-EAA groups [Risk ratio (RR): 0.68; 95% CI: 0.41 to 1.13, p = 0.14, I² = 73%], but the certainty of evidence was very low. Nevertheless, the EAA group had lower pain score at postoperative 24 h [mean difference (MD): -1.49, 95% CI: -2.38 to -0.61; I² = 98%; five RCTs; n = 476] and risk of PONV (RR = 0.73, 95% CI: 0.57 to 0.93, p = 0.01, I² = 0%; three RCTs, 1876 patients) than those in the non-EAA group. Our results showed no significant impact of EAA on the pain score at postoperative 36-72 h, LOS, and risk of complications.

CONCLUSION

This meta-analysis demonstrated that EAA had no significant impact on the incidence of POD/POCD in patients following non-cardiac surgery.

Safety Evaluation of Cervical Dorsal Instrumentation in Geriatric Patients: Experience at a Level 1 Center for Spinal Surgery-A Single Center Cohort Study

Objective

Dorsal instrumentation of the cervical spine is an established treatment in spine surgery. However, careful planning is required, particularly in elderly patients. This study evaluates early clinical outcomes in geriatric patients undergoing complex spine surgery.

Methods

In this retrospective, single center cohort study, we included all geriatric patients (aged ≥65 years) who underwent dorsal instrumentation between January 2013 and December 2020. We analyzed postoperative complications and the 30-day in-hospital mortality rate. Furthermore, the Charlson comorbidity index (CCI) and Clavien-Dindo grading system (CDG) were used to assess the patients' comorbidity burden.

Results

In total, 153 patients were identified and included. The mean age of patients was 78 years (SD ± 7). Traumatic injury (53.6%) was the most common reason for surgery. 60.8% of the patients underwent dorsal instrumentation with 3 or more levels. The most common comorbidities were arterial hypertension (64%), diabetes mellitus (22.2%), coronary heart disease and atrial fibrillation (19.6%). The most common adverse event (AE) was pneumonia (4%) and the most common surgery-related complication was wound infection (5.2%). Among patients categorized as high risk for AE (CCI > 5), 14.6% suffered a postoperative AE. In our univariate analysis, we found no risk factors for high rates of complications or mortality.

Conclusion

Our data demonstrates that older patients were at no significant risk of postoperative complications. The CCI/CDG scores may identify patients at higher risk for adverse events after dorsal instrumentation, and these assessments should become an essential component of stratification in this older patient population.

Postoperative outcomes in older surgical patients with preoperative cognitive impairment: A systematic review and meta-analysis

STUDY OBJECTIVE

To determine the effect of cognitive impairment (CI) and dementia on adverse outcomes in older surgical patients.

DESIGN

A systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs). Various databases were searched from their inception dates to March 8, 2021.

SETTING

Preoperative assessment.

PATIENTS

Older patients (≥ 60 years) undergoing non-cardiac surgery.

MEASUREMENTS

Outcomes included postoperative delirium, mortality, discharge to assisted care, 30-day readmissions, postoperative complications, and length of hospital stay. Effect sizes were calculated as Odds Ratio (OR) and Mean Difference (MD) based on random effect model analysis. The quality of included studies was assessed using the Cochrane Risk Bias Tool for RCTs and Newcastle-Ottawa Scale for observational cohort studies.

RESULTS

Fifty-three studies (196,491 patients) were included. Preoperative CI was associated with a significant risk of delirium in older patients after non-cardiac surgery (25.1% vs. 10.3%; OR: 3.84; 95%CI: 2.35, 6.26; I²: 76%; p < 0.00001). Cognitive impairment (26.2% vs. 13.2%; OR: 2.28; 95%CI: 1.39, 3.74; I²: 73%; p = 0.001) and dementia (41.6% vs. 25.5%; OR: 1.96; 95%CI: 1.34, 2.88; I²: 99%; p = 0.0006) significantly increased risk for 1-year mortality. In patients with CI, there was an increased risk of discharge to assisted care (44.7% vs. 38.3%; OR 1.74; 95%CI: 1.05, 2.89, p = 0.03), 30-day readmissions (14.3% vs. 10.8%; OR: 1.36; 95%CI: 1.00, 1.84, p = 0.05), and postoperative complications (40.7% vs. 18.8%; OR: 1.85; 95%CI: 1.37, 2.49; p < 0.0001).

CONCLUSIONS

Preoperative CI in older surgical patients significantly increases risk of delirium, 1-year mortality, discharge to assisted care, 30-day readmission, and postoperative complications. Dementia increases the risk of 1-year mortality. Cognitive screening in the preoperative assessment for older surgical patients may be helpful for risk stratification so that appropriate management can be implemented to mitigate adverse postoperative outcomes.

Anticholinergic Drug Exposure Increases the Risk of Delirium in Older Patients Undergoing Elective Surgery

Introduction

Postoperative delirium (POD) is a common and serious adverse event of surgery in older people. Because of its great impact on patients' safety and quality of life, identification of modifiable risk factors could be useful. Although preoperative medication intake is assumed to be an important modifiable risk factor, the impact of anticholinergic drugs on the occurrence of POD seems underestimated in elective surgery. The aim of this study was to investigate the association between preoperative anticholinergic burden and POD. We hypothesized that a high preoperative anticholinergic burden is an independent, potentially modifiable predisposing and precipitating factor of POD in older people.

Methods

Between November 2017 and April 2019, 1,470 patients of 70 years and older undergoing elective orthopedic, general, cardiac, or vascular surgery were recruited in the randomized, prospective, multicenter PAWEL trial. Anticholinergic burden of a sub-cohort of 899 patients, who did not receive a multimodal intervention for preventing POD, was assessed by two different tools at hospital admission: The established Anticholinergic Risk Scale (ARS) and the recently developed Anticholinergic Burden Score (ABS). POD was detected by confusion assessment method (CAM) and a validated post discharge medical record review. Logistic regression analyses were performed to evaluate the association between anticholinergic burden and POD.

Results

POD was observed in 210 of 899 patients (23.4%). Both ARS and ABS were independently associated with POD. The association persisted after adjustment for relevant confounding factors such as age, sex, comorbidities, preoperative cognitive and physical status, number of prescribed drugs, surgery time, type of surgery and anesthesia, usage of heart-lung-machine, and treatment in intensive care unit. If a patient was taking one of the 56 drugs listed in the ABS, risk for POD was 2.7-fold higher (OR = 2.74, 95% CI = 1.55–4.94) and 1.5-fold higher per additional point on the ARS (OR = 1.54, 95% CI = 1.15–2.02).

Conclusion

Preoperative anticholinergic drug exposure measured by ARS or ABS was independently associated with POD in older patients undergoing elective surgery. Therefore, identification, discontinuation or substitution of anticholinergic medication prior to surgery may be a promising approach to reduce the risk of POD in older patients.

Applying Evidence-based Principles to Guide Emergency Surgery in Older Adults

Although outcomes for older adults undergoing elective surgery are generally comparable to younger patients, outcomes associated with emergency surgery are poor. These adverse outcomes are in part because of the physiologic changes associated with aging, increased odds of comorbidities in older adults, and a lower probability of presenting with classic "red flag" physical examination findings. Existing evidence-based perioperative best practice guidelines perform better for elective compared with emergency surgery; so, decision making for older adults undergoing emergency surgery can be challenging for surgeons and other clinicians and may rely on subjective experience. To aid surgical decision making, clinicians should assess premorbid functional status, evaluate for the presence of geriatric syndromes, and consider social determinants of health. Documentation of care preferences and a surrogate decision maker are critical. In discussing the risks and benefits of surgery, patient-centered narrative formats with inclusion of geriatric-specific outcomes are important. Use of risk calculators can be meaningful, although limitations exist. After surgery, daily evaluation for common postoperative complications should be considered, as well as early discharge planning and palliative care consultation, if appropriate. The role of the geriatrician in emergency surgery for older adults may vary based on the acuity of patient presentation, but perioperative consultation and comanagement are strongly recommended to optimize care delivery and patient outcomes.

The Relationship between Perioperative Blood Transfusion and Postoperative Delirium in Patients Undergoing Spinal Fusion Surgery: Clinical Data Warehouse Analysis

Background and Objectives: For preventing postoperative delirium (POD), identifying the risk factors is important. However, the relationship between blood transfusion and POD is still controversial. The aim of this study was to identify the risk factors of POD, to evaluate the impact of blood transfusion in developing POD among people undergoing spinal fusion surgery, and to show the effectiveness of big data analytics using a clinical data warehouse (CDW). Materials and Methods: The medical data of patients who underwent spinal fusion surgery were obtained from the CDW of the five hospitals of Hallym University Medical Center. Clinical features, laboratory findings, perioperative variables, and medication history were compared between patients without POD and with POD. Results: 234 of 3967 patients (5.9%) developed POD. In multivariate logistic regression analysis, the risk factors of POD were as follows: Parkinson’s disease (OR 5.54, 95% CI 2.15–14.27; p < 0.001), intensive care unit (OR 3.45 95% CI 2.42–4.91; p < 0.001), anti-psychotics drug (OR 3.35 95% CI 1.91–5.89; p < 0.001), old age (≥70 years) (OR 3.08, 95% CI 2.14–4.43; p < 0.001), depression (OR 2.8 95% CI 1.27–6.2; p < 0.001). The intraoperative transfusion (OR 1.1, 95% CI 0.91–1.34; p = 0.582), and the postoperative transfusion (OR 0.91, 95% CI 0.74–1.12; p = 0.379) had no statistically significant effect on the incidence of POD. Conclusions: There was no relationship between perioperative blood transfusion and the incidence of POD in spinal fusion surgery. Big data analytics using a CDW could be helpful for the comprehensive understanding of the risk factors of POD, and for preventing POD in spinal fusion surgery.

Mitochondrial DNA methylation drift and postoperative delirium in mice

BACKGROUND

Mitochondrial dysfunction is linked to the etiopathogenesis of postoperative delirium (POD), which severely affects the prognosis of elderly patients undergoing surgery. The methylation of mitochondrial DNA (mtDNA), a new and incompletely described phenomenon that regulates the structure and function of mitochondria, is associated with ageing. However, the relationship between mtDNA methylation and POD has not been established.

OBJECTIVE

To explore the potential roles of mitochondrial epigenetic regulation in POD.

DESIGN

A randomised animal study.

PARTICIPANTS

Eighty-eight 6-month-old and one hundred seventy-six 18-month-old male C57BL/6N mice.

INTERVENTIONS

POD was induced by abdominal surgery under 1.4% isoflurane for 2 h. Behavioural tests were performed at 24 h before surgery and at 6, 9 and 24 h after surgery.

MAIN OUTCOME MEASURES

5-methylcytosine (5-mC) at five CpG sites of the displacement loop (D-loop) and at 60 CpG sites of coding gene loci in the mitochondrial genome after surgery of the hippocampus, prefrontal cortex, amygdala and anterior cingulate cortex in 6 and 18-month-old mice were detected using bisulfite pyrosequencing. Mitochondrial structure, mitochondrial gene expression and mtDNA copy number were also examined using Electron microscopy and real time PCR to find the association with mtDNA methylation.

RESULTS

The mtDNA methylation drift manifested as a decrease in the methylation levels at the D-loop and an increase or decrease in the methylation levels at several coding gene loci, ultimately resulting in reduced mtDNA copy numbers, altered mitochondrial gene expression and damaged mitochondrial structures in the hippocampus and prefrontal cortex after surgery. The activation of Silent information regulator-1 (SIRT1) ameliorated anaesthesia-induced and surgery-induced mitochondrial dysfunction and delirium-like behaviours by regulating mtDNA methyltransferase-mediated mtDNA methylation.

CONCLUSION

These data support the existence of epigenetic mtDNA regulation in POD; however, further studies are required to explore the specific mechanisms.

TRIAL REGISTRATION

No 20181204 Drum tower hospital.

Incidence and factors associated with postoperative delirium in patients undergoing transurethral resection of bladder tumor

Background

Postoperative delirium is an important complication after surgery, including urological surgery. This study evaluated the incidence of postoperative delirium and its associated factors after transurethral resection of bladder tumor in adult patients.

Methods

Patients aged ≥20 years who underwent elective transurethral resection of bladder tumor under general anesthesia from April 2016 to November 2020 were included. Patient demographic and intraoperative data, including the administration of 5-aminolevulinic acid and hypotension, defined as a mean arterial pressure value < 60 mmHg, were evaluated. The primary outcome was the incidence of postoperative delirium assessed using a chart-based method. The factors associated with postoperative delirium were explored using multiple logistic regression analysis. Postoperative lengths of stay between patients with and without postoperative delirium were compared using the Mann–Whitney U-test.

Results

Of 324 eligible patients with a median age of 76, 26 patients experienced postoperative delirium, with an incidence rate of 8.0% (95% confidence interval, 5.06–10.9). Age (odds ratio 1.13, 95% confidence interval 1.05–1.22, p = 0.001) and body mass index (odds ratio 0.83, 95% confidence interval 0.71–0.97, p = 0.02) were associated with postoperative delirium. Postoperative length of stay between patients with or without postoperative delirium was not significantly different (6 vs 6 days, p = 0.18).

Conclusions

The incidence of postoperative delirium after transurethral resection of bladder tumor under general anesthesia in this study was 8.0%. Older age and low body mass index were associated with development of postoperative delirium.

Association between the reactivity of local cerebral oxygen saturation after hypo-to-hypercapnic tests and delirium after abdominal surgery in older adults: A prospective study

OBJECTIVE

This study aimed to investigate the correlation between changes in regional cerebral oxygen saturation (rSO2) and postoperative delirium in older adults undergoing major abdominal surgery.

MATERIALS AND METHODS

This prospective study enrolled older adults scheduled for elective major abdominal surgery at the Second Affiliated Hospital of Anhui Medical University from August 2021 to January 2022. The change in rSO2 from baseline was determined using the hypo-to-hypercapnic test. The main study outcome was the occurrence of postoperative delirium.

RESULTS

A total of 101 participants were included for analysis, of whom 16 (15.8%) developed postoperative delirium. Compared with non-delirium participants, the mean arterial pressure and heart rate were not significantly different in the postoperative delirium group at T0, T1, T2, T3, T4, and T6 (all P_interaction > 0.05), but the delirium group had lower pH, lower PaO2, and higher lactate levels at T4, T5, and T6 (all P_interaction < 0.05). rSO2 at T0, T1, T2, T3, T4, and T6 was 69.0 (63.2-75.2), 70.7 ± 7.3, 68.2 ± 7.5, 72.1 ± 8.0, 69.9 ± 7.8, 67.4 ± 7.2, and 71.7 ± 8.1, respectively. The postoperative change in rSO2 during the hypercapnia test (TΔrSO2%) was 6.62 (5.31-9.36). Multivariable analysis showed that the Cumulative Illness Rating Scale (odd ratio, OR = 1.89, 95% confidence interval, CI: 1.10-3.25, P = 0.021), preoperative albumin levels (OR = 0.67, 95% CI: 0.48-0.94, P = 0.022), rSO2 at T4 (OR = 0.61, 95% CI: 0.41-0.89, P = 0.010), and postoperative TΔrSO2% (OR = 0.80, 95% CI: 0.66-0.98, P = 0.028) were independently associated with postoperative delirium in older adults undergoing elective abdominal surgery.

CONCLUSION

The rSO2 measured at T4 and postoperative TΔrSO2% were independently associated with postoperative delirium in older adults undergoing elective abdominal surgery.