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ImportanceAlthough the incidence of acute appendicitis among adults 65 years and older is high, these patients are underrepresented in randomized clinical trials comparing nonoperative vs operative management of appendicitis; it is unclear whether current trial data can be used to guide treatment in older adults.ObjectiveTo compare outcomes following nonoperative vs operative management of appendicitis in older adults and assess whether they differ from results in younger patients.Design, Setting, and ParticipantsThis retrospective cohort study used US hospital admissions data from the Agency for Healthcare Research and Quality’s National Inpatient Sample from 2004 to 2017. Of 723 889 adult patients with acute uncomplicated appendicitis, 474 845 with known procedure date who survived 24 hours postprocedure and did not have inflammatory bowel disease were included (43 846 who were treated nonoperatively and 430 999 with appendectomy) were included. Data were analyzed from October 2021 to April 2022.ExposuresNonoperative vs operative management.Main Outcomes and MeasuresThe primary outcome was incidence of posttreatment complications. Secondary outcomes included mortality, length of stay, and inpatient costs. Differences were estimated using inverse probability weighting of the propensity score with sensitivity analysis to quantify effects of unmeasured confounding.ResultsThe median (IQR) age in the overall cohort was 39 (27-54) years, and 29 948 participants (51.3%) were female. In patients 65 years and older, nonoperative management was associated with a 3.72% decrease in risk of complications (95% CI, 2.99-4.46) and a 1.82% increase in mortality (95% CI, 1.49-2.15) along with increased length of hospitalization and costs. Outcomes in patients younger than 65 years were significantly different than in older adults, with only minor differences between nonoperative and operative management with respect to morbidity and mortality, and smaller differences in length of hospitalization and costs. Morbidity and mortality results were somewhat sensitive to bias from unmeasured confounding.Conclusions and RelevanceNonoperative management was associated with reduced complications in older but not younger patients; however, operative management was associated with reduced mortality, hospital length of stay, and overall costs across all age groups. The different outcomes of nonoperative vs operative management of appendicitis in older and younger adults highlights the need for a randomized clinical trial to determine the best approach for managing appendicitis in older patients.

Background Cognitive dysfunction after surgery is a major issue in older adults. Here, we determined the effect of APOE4 on perioperative neurocognitive function in older patients. Methods We enrolled 140 English-speaking patients ≥60 yr old scheduled for noncardiac surgery under general anaesthesia in an observational cohort study, of whom 52 underwent neuroimaging. We measured cognition; Aβ, tau, p-tau levels in CSF; and resting-state intrinsic functional connectivity in six Alzheimer's disease-risk regions before and 6 weeks after surgery. Results There were no significant APOE4-related differences in cognition or CSF biomarkers, except APOE4 carriers had lower CSF Aβ levels than non-carriers (preoperative median CSF Aβ [median absolute deviation], APOE4 305 pg ml−1 [65] vs 378 pg ml−1 [38], respectively; P=0.001). Controlling for age, APOE4 carriers had significantly greater preoperative functional connectivity than non-carriers between several brain regions implicated in Alzheimer's disease, including between the left posterior cingulate cortex and left angular gyrus (β [95% confidence interval, CI], 0.218 [0.137–0.230]; PFWE=0.016). APOE4 carriers, but not non-carriers, experienced significant connectivity decreases from before to 6 weeks after surgery between several brain regions including between the left posterior cingulate cortex and left angular gyrus (β [95% CI], –0.196 [–0.256 to –0.136]; PFWE=0.001). Most preoperative and postoperative functional connectivity differences did not change after controlling for preoperative CSF Aβ levels. Conclusions Postoperative change trajectories for cognition and CSF Aβ, tau or p-tau levels did not differ between community dwelling older APOE4 carriers and non-carriers. APOE4 carriers showed greater preoperative functional connectivity and greater postoperative decreases in functional connectivity in key Alzheimer's disease-risk regions, which occur via Aβ-independent mechanisms.

In 2003, randomized trials demonstrated potentially improved outcomes when local instead of general anesthesia is used for inguinal hernia repair. Our study aimed to evaluate how the use of local anesthesia for this procedure changed over time following the publication of the trials' level 1 evidence.We used the 1998-2018 Veterans Affairs Surgical Quality Improvement Program database to identify adults who underwent open, unilateral inguinal hernia repair under local or general anesthesia. Our primary outcome was the percentage of cases performed under local anesthesia. We used a time-series design to examine the trend and rate of change of the use of local anesthesia.We included 97,437 veterans, of which 22,333 (22.9%) had hernia surgery under local anesthesia. The median age of veterans receiving local anesthesia remained stable at 64-67 years over time. The use of local anesthesia decreased steadily, from 38.2% at the beginning year to 15.1% in the final year (P 0.0001). The publication of results from randomized trials (in 2003) did not appear to increase the overall use or change the rate of decline in the use of local anesthesia. Overall, we found that the use of local anesthesia decreased by about 1.5% per year.The utilization of local anesthesia for inguinal hernia repair in the VA has steadily declined over the last 20 + years, despite data showing equivalence or superiority to general anesthesia. Future studies should explore barriers to the use of local anesthesia for hernia repair.

Background The optimal anesthesia modality for umbilical hernia repair is unclear. We hypothesized that using local rather than general anesthesia would be associated with improved outcomes, especially for frail patients. Methods We utilized the 1998-2018 Veterans Affairs Surgical Quality Improvement Program to identify patients who underwent elective, open umbilical hernia repair under general or local anesthesia. We used the Risk Analysis Index to measure frailty. Outcomes included complications and operative time. Results There were 4958 Veterans (13%) whose hernias were repaired under local anesthesia. Compared to general anesthesia, local was associated with a 12%-24% faster operative time for all patients, and an 86% lower (OR 0.14, 95%CI 0.03-0.72) complication rate for frail patients. Conclusions Local anesthesia may reduce the operative time for all patients and complications for frail patients having umbilical hernia repair.

ImportanceAdvocates of laparoscopic surgery argue that all inguinal hernias, including initial and unilateral ones, should be repaired laparoscopically. Prior work suggests outcomes of open repair are improved by using local rather than general anesthesia, but no prior studies have compared laparoscopic surgery with open repair under local anesthesia.ObjectiveTo evaluate postoperative outcomes of open inguinal hernia repair under general or local anesthesia compared with laparoscopic repair.Design, Setting, and ParticipantsThis retrospective cohort study identified 107 073 patients in the Veterans Affairs Surgical Quality Improvement Program database who underwent unilateral initial inguinal hernia repair from 1998 to 2019. Data were analyzed from October 2021 to March 2022.ExposuresPatients were divided into 3 groups for comparison: (1) open repair with local anesthesia (n = 22 333), (2) open repair with general anesthesia (n = 75 104), and (3) laparoscopic repair with general anesthesia (n = 9636).Main Outcomes and MeasuresOperative time and postoperative morbidity were compared using quantile regression and inverse probability propensity weighting. A 2-stage least-squares regression and probabilistic sensitivity analysis was used to quantify and address bias from unmeasured confounding in this observational study.ResultsOf 107 073 included patients, 106 529 (99.5%) were men, and the median (IQR) age was 63 (55-71) years. Compared with open repair with general anesthesia, laparoscopic repair was associated with a nonsignificant 0.15% (95% CI, −0.39 to 0.09; P = .22) reduction in postoperative complications. There was no significant difference in complications between laparoscopic surgery and open repair with local anesthesia (−0.05%; 95% CI, −0.34 to 0.28; P = .70). Operative time was similar for the laparoscopic and open general anesthesia groups (4.31 minutes; 95% CI, 0.45-8.57; P = .048), but operative times were significantly longer for laparoscopic compared with open repair under local anesthesia (10.42 minutes; 95% CI, 5.80-15.05; P Conclusions and RelevanceIn this study, laparoscopic and open repair with local anesthesia were reasonable options for patients with initial unilateral inguinal hernias, and the decision should be made considering both patient and surgeon factors.

BACKGROUND Some older adults show exaggerated responses to drugs that act on the brain. The brain's response to anesthetic drugs is often measured clinically by processed electroencephalogram (EEG) indices. Thus, we developed a processed EEG-based measure of the brain's resistance to volatile anesthetics and hypothesized that low scores on it would be associated with postoperative delirium risk. METHODS We defined the Duke Anesthesia Resistance Scale (DARS) as the average bispectral index (BIS) divided by the quantity (2.5 minus the average age-adjusted end-tidal minimum alveolar concentration [aaMAC] inhaled anesthetic fraction). The relationship between DARS and postoperative delirium was analyzed in 139 older surgical patients (age ≥65) from Duke University Medical Center (n = 69) and Mt Sinai Medical Center (n = 70). Delirium was assessed by geriatrician interview at Duke, and by research staff utilizing the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) instrument at Mt Sinai. We examined the relationship between DARS and delirium and used the Youden index to identify an optimal low DARS threshold (for delirium risk), and its associated 95% bootstrap confidence bounds. We used multivariable logistic regression to examine the relationship between low DARS and delirium risk. RESULTS The relationship between DARS and delirium risk was nonlinear, with higher delirium risk at low DARS scores. A DARS threshold of 28.755 maximized the Youden index for the association between low DARS and delirium, with bootstrap 95% confidence bounds of 26.18 and 29.80. A low DARS (

This narrative review examines the current evidence on whether obstructive sleep apnea (OSA) is associated with postoperative delirium (POD) and postoperative cognitive dysfunction (POCD). The mechanisms that could predispose OSA patients to these disorders are also explored.Relevant literature was identified by searching for pertinent terms in MedlineSeven studies have investigated the association between OSA and POD, with mixed results. No studies have examined the potential link between OSA and POCD. If these relationships exist, they could be mediated by several mechanisms, including increased neuroinflammation, blood-brain barrier breakdown, cerebrovascular disease, Alzheimer's disease neuropathology, disrupted cerebral autoregulation, sleep disruption, sympathovagal imbalance, and/or disrupted brain bioenergetics.There is very limited evidence that OSA plays a role in postoperative neurocognitive disorders because few studies have been conducted in the perioperative setting. Additional perioperative prospective observational cohort studies and randomized controlled trials of sleep apnea treatment are needed. These investigations should also assess potential underlying mechanisms that could predispose patients with OSA to postoperative neurocognitive disorders. This review highlights the need for more research to improve postoperative neurocognitive outcomes for patients with OSA.RéSUMé: OBJECTIF: Ce compte rendu narratif examine les données probantes actuelles quant à l’association entre l’apnée obstructive du sommeil (AOS) et le syndrome confusionnel postopératoire (SCPO) ainsi que le dysfonctionnement cognitif postopératoire (DCPO). Les mécanismes qui pourraient prédisposer les patients atteints d’AOS à ces troubles sont également explorés.La littérature concordante a été identifiée en recherchant des termes pertinents dans les bases de données MedlineSept études ont examiné l’association entre l’AOS et le SCPO, avec des résultats mitigés. Aucune étude n’a exploré le lien potentiel entre l’AOS et le DCPO. Si ces relations existent, elles pourraient être médiées par plusieurs mécanismes, notamment une neuroinflammation accrue, une dégradation de la barrière hémato-encéphalique, une maladie cérébrovasculaire, une neuropathologie de la maladie d’Alzheimer, une autorégulation cérébrale perturbée, une perturbation du sommeil, un déséquilibre sympathovagal et / ou une bioénergétique cérébrale perturbée.Il existe très peu de données probantes soutenant que l’AOS joue un rôle dans les troubles neurocognitifs postopératoires parce que peu d’études ont été menées dans le contexte périopératoire. D’autres études de cohorte observationnelles prospectives périopératoires et des études randomisées contrôlées sur le traitement de l’apnée du sommeil sont nécessaires. Ces études devraient également évaluer les mécanismes sous-jacents potentiels qui pourraient prédisposer les patients atteints d’AOS à des troubles neurocognitifs postopératoires. Ce compte rendu souligne la nécessité de recherches supplémentaires pour améliorer les devenirs neurocognitifs postopératoires des patients atteints d’AOS.

Background Inguinal hernia repair is the most common general surgery procedure and can be performed under local or general anesthesia. We hypothesized that using local rather than general anesthesia would improve outcomes, especially for older adults. Methods This is a retrospective review of 97,437 patients in the Veterans Affairs Surgical Quality Improvement Program who had open inguinal hernia surgery under local or general anesthesia. Outcomes included 30-day postoperative complications, operative time, and recovery time. Results Our cohort included 22,333 (23%) Veterans who received local and 75,104 (77%) who received general anesthesia. Mean age was 62 years. Local anesthesia was associated with a 37% decrease in the odds of postoperative complications (95% CI 0.54–0.73), a 13% decrease in operative time (95% CI 17.5–7.5), and a 27% shorter recovery room stay (95% CI 27.5–25.5), regardless of age. Conclusions Using local rather than general anesthesia is associated with a profound decrease in complications (equivalent to “de-aging” patients by 30 years) and could significantly reduce costs for this common procedure.

BACKGROUND: Inguinal hernia repair is the most common general surgery operation in the United States. Nearly 80% of inguinal hernia operations are performed under general anesthesia versus 15%–20% using local anesthesia, despite the absence of evidence for superiority of the former. Although patients aged 65 years and older are expected to benefit from avoiding general anesthesia, this presumed benefit has not been adequately studied. We hypothesized that the benefits of local over general anesthesia for inguinal hernia repair would increase with age. MATERIALS AND METHODS: We analyzed 87,794 patients in the American College of Surgeons National Surgical Quality Improvement Project who had elective inguinal hernia repair under local or general anesthesia from 2014–2018, and we used propensity scores to adjust for known confounding. We compared postoperative complications, 30-day readmissions, and operative time for patients aged

Background: APOE4 has been hypothesized to increase Alzheimer’s disease risk by increasing neuroinflammation, though the specific neuroinflammatory pathways involved are unclear. Objective: Characterize cerebrospinal fluid (CSF) proteomic changes related to APOE4 copy number. Methods: We analyzed targeted proteomic data from ADNI CSF samples using a linear regression model adjusting for age, sex, and APOE4 copy number, and additional linear models also adjusting for AD clinical status or for CSF Aβ, tau, or p-tau levels. False discovery rate was used to correct for multiple comparisons correction. Results: Increasing APOE4 copy number was associated with a significant decrease in a CRP peptide level across all five models (q

Objective The present work evaluates the relationship between postoperative immune and neurovascular changes and the pathogenesis of surgery-induced delirium superimposed on dementia. Background and rationale Postoperative delirium is a common complication in many older adults and in patients with dementia including Alzheimer's disease (AD). The course of delirium can be particularly debilitating, while its pathophysiology remains poorly defined. Historical evolution As of 2019, an estimated 5.8 million people of all ages have been diagnosed with AD, 97% of whom are >65 years of age. Each year, many of these patients require surgery. However, anesthesia and surgery can increase the risk for further cognitive decline. Surgery triggers neuroinflammation both in animal models and in humans, and a failure to resolve this inflammatory state may contribute to perioperative neurocognitive disorders as well as neurodegenerative pathology. Updated hypothesis We propose an immunovascular hypothesis whereby dysregulated innate immunity negatively affects the blood-brain interface, which triggers delirium and thereby exacerbates AD neuropathology. Early experimental data We have developed a translational model to study delirium superimposed on dementia in APPSwDI/mNos2-/- AD mice (CVN-AD) after orthopedic surgery. At 12 months of age, CVN-AD showed distinct neuroimmune and vascular impairments after surgery, including acute microgliosis and amyloid-β deposition. These changes correlated with attention deficits, a core feature of delirium-like behavior. Future experiments and validation studies Future research should determine the extent to which prevention of surgery-induced microgliosis and/or neurovascular unit dysfunction can prevent or ameliorate postoperative memory and attention deficits in animal models. Translational human studies should evaluate perioperative indices of innate immunity and neurovascular integrity and assess their potential link to perioperative neurocognitive disorders. Major challenges for the hypothesis Understanding the complex relationships between delirium and dementia will require mechanistic studies aimed at evaluating the role of postoperative neuroinflammation and blood-brain barrier changes in the setting of pre-existing neurodegenerative and/or aging-related pathology. Linkage to other major theories Non-resolving inflammation with vascular disease that leads to cognitive impairments and dementia is increasingly important in risk stratification for AD in the aging population. The interdependence of these factors with surgery-induced neuroinflammation and cognitive dysfunction is also becoming apparent, providing a strong platform for assessing the relationship between postoperative delirium and longer term cognitive dysfunction in older adults.

OBJECTIVE: Lumbar punctures (LPs) are important for obtaining CSF in neurology studies but are associated with adverse events and feared by many patients. We determined adverse event rates and pain scores in patients prospectively enrolled in two cohort studies who underwent LPs using a standardized protocol and 25g needle. METHODS: 809 LPs performed in 262 patients age ≥60 years in the MADCO-PC and INTUIT studies were analyzed. Medical records were monitored for LP-related adverse events, and patients were queried about subjective complaints. We analyzed adverse event rates, including headaches and pain scores. RESULTS: There were 22 adverse events among 809 LPs performed, a rate of 2.72% (95% CI 1.71% – 4.09%). Patient hospital stay did not increase due to adverse events. Four patients (0.49%) developed a post-lumbar puncture headache (PLPH). Twelve patients (1.48%) developed nausea, vasovagal responses, or headaches that did not meet PLPH criteria. Six patients (0.74%) reported lower back pain at the LP site not associated with muscular weakness or paresthesia. The median pain score was 1 [0, 3]; the mode was 0 out of 10. CONCLUSIONS: The LP protocol described herein may reduce adverse event rates and improve patient comfort in future studies.

Hevin/Sparcl1 is an astrocyte-secreted protein and regulates synapse formation in the brain. Here we show that astrocytic hevin signaling plays a critical role in maintaining chronic pain. Compared to wild-type mice, hevin-null mice exhibited normal mechanical and heat sensitivity but reduced inflammatory pain. Interestingly, hevin is required for the maintenance of nerve injury-induced neuropathic pain (mechanical allodynia), and hevin-null mice have faster recovery than wild-type mice from neuropathic pain after nerve injury. Intrathecal injection of wild-type hevin but not a hevin mutant that is no longer synaptogenic was sufficient to induce persistent mechanical allodynia in naïve mice and further enhanced neuropathic pain in animals with nerve injury. In hevin-null mice with nerve injury, AAV-mediated re-expression of hevin, but not mutant hevin, in GFAP-expressing spinal cord astrocytes could reinstate neuropathic pain. Mechanistically, hevin is crucial for spinal cord NMDA receptor (NMDAR) signaling, as NMDA-induced mechanical allodynia and inward currents in spinal cord lamina II neurons is reduced in hevin-null mice. Hevin potentiated NMDA currents mediated by the GluN2B-containing NMDARs. Furthermore, intrathecal injection of a neutralizing antibody against hevin alleviated acute inflammatory pain and persistent neuropathic pain. Secreted hevin was detected in mouse cerebrospinal fluid (CSF) and nerve injury significantly increased CSF hevin abundance. Finally, neurosurgery caused rapid (< 10 hours) and substantial increases (~20 fold) in HEVIN levels in human CSF. Collectively, our findings support a critical role of hevin and astrocytes in the maintenance of chronic pain. Neutralizing of secreted hevin with monoclonal antibody may provide a new therapeutic strategy for treating chronic pain and NMDAR-medicated neurodegeneration.

Numerous investigators have theorized that postoperative changes in Alzheimer's disease neuropathology may underlie postoperative neurocognitive disorders. Thus, we determined the relationship between postoperative changes in cognition and cerebrospinal (CSF) tau, p-tau-181p, or Aβ levels after non-cardiac, non-neurologic surgery in older adults.Participants underwent cognitive testing before and 6 weeks after surgery, and lumbar punctures before, 24 h after, and 6 weeks after surgery. Cognitive scores were combined via factor analysis into an overall cognitive index. In total, 110 patients returned for 6-week postoperative testing and were included in the analysis.There was no significant change from before to 24 h or 6 weeks following surgery in CSF tau (median [median absolute deviation] change before to 24 h: 0.00 [4.36] pg/mL, p = 0.853; change before to 6 weeks: -1.21 [3.98] pg/mL, p = 0.827). There were also no significant changes in CSF p-tau-181p or Aβ over this period. There was no change in cognitive index (mean [95% CI] 0.040 [-0.018, 0.098], p = 0.175) from before to 6 weeks after surgery, although there were postoperative declines in verbal memory (-0.346 [-0.523, -0.170], p = 0.003) and improvements in executive function (0.394, [0.310, 0.479], p 0.001). There were no significant correlations between preoperative to 6-week postoperative changes in cognition and CSF tau, p-tau-181p, or Aβ42 changes over this interval (p 0.05 for each).Neurocognitive changes after non-cardiac, non-neurologic surgery in the majority of cognitively healthy, community-dwelling older adults are unlikely to be related to postoperative changes in AD neuropathology (as assessed by CSF Aβ, tau or p-tau-181p levels or the p-tau-181p/Aβ or tau/Aβ ratios).clinicaltrials.gov (NCT01993836).

Animal models suggest POCD may be caused by brain monocyte influx. To study this in humans, we developed a flow cytometry panel to profile CSF samples collected before and after major non-cardiac surgery in in 5 patients age ≥ 60 years who developed POCD and 5 matched controls who did not. We detected 12,654±4895 cells/10 ml CSF sample (mean±SD). Patients who developed POCD showed an increased CSF monocyte/lymphocyte ratio and MCP-1 receptor downregulation on CSF monocytes 24 hours after surgery. These pilot data demonstrate that CSF flow cytometry can be used to study mechanisms of postoperative neurocognitive dysfunction. CLINICAL TRIAL NUMBER AND REGISTRY URL: , https://clinicaltrials.gov/ct2/show/NCT01993836 (This manuscript describes a nested case-control study, performed within the larger cohort study, .)

Cognitive recovery after anaesthesia and surgery is a concern for older adults, their families, and caregivers. Reports of patients who were 'never the same' prompted a scientific inquiry into the nature of what patients have experienced. In June 2018, the ASA Brain Health Initiative held a summit to discuss the state of the science on perioperative cognition, and to create an implementation plan for patients and providers leveraging the current evidence. This group included representatives from the AARP (formerly the American Association of Retired Persons), American College of Surgeons, American Heart Association, and Alzheimer's Association Perioperative Cognition and Delirium Professional Interest Area. This paper summarises the state of the relevant clinical science, including risk factors, identification and diagnosis, prognosis, disparities, outcomes, and treatment of perioperative neurocognitive disorders. Finally, we discuss gaps in current knowledge with suggestions for future directions and opportunities for clinical and translational projects.

Background Minimum alveolar concentration (MAC) and MAC-awake decrease with age. We hypothesised that, in clinical practice, (i) end-tidal MAC fraction in older patients would decline by less than the predicted age-dependent MAC decrease (i.e. older patients would receive relatively excessive anaesthetic concentrations), and (ii) bispectral index (BIS) values would therefore be lower in older patients. Methods We examined the relationship between end-tidal MAC fraction, BIS values, and age in 4699 patients > 30 yr in age at a single centre using unadjusted local regression (locally estimated scatterplot smoothing), Spearman's correlation, stratification, and robust univariable and multivariable linear regression. Results The end-tidal MAC fraction in older patients declined by 3.01% per decade (95% confidence interval [CI]: 2.56–3.45; P Conclusions The age-dependent decline in end-tidal MAC fraction delivered in clinical practice at our institution was less than the age-dependent percentage decrease in MAC and MAC-awake determined from published studies. Despite receiving higher aaMAC fractions, older patients paradoxically showed higher BIS values. This most likely suggests that the BIS algorithm is inaccurate in older adults.

Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Cognitive decline after cardiac surgery occurs frequently and persists in a significant proportion of patients. Preclinical studies and human trials suggest that intravenous lidocaine may confer protection in the setting of neurologic injury. It was hypothesized that lidocaine administration would reduce cognitive decline after cardiac surgery compared to placebo. Methods After institutional review board approval, 478 patients undergoing cardiac surgery were enrolled into this multicenter, prospective, randomized, double-blinded, placebo-controlled, parallel group trial. Subjects were randomized to lidocaine 1 mg/kg bolus after the induction of anesthesia followed by a continuous infusion (48 μg · kg−1 · min−1 for the first hour, 24 μg · kg−1 · min−1 for the second hour, and 10 μg · kg−1 · min−1 for the next 46 h) or saline with identical volume and rate changes to preserve blinding. Cognitive function was assessed preoperatively and at 6 weeks and 1 yr postoperatively using a standard neurocognitive test battery. The primary outcome was change in cognitive function between baseline and 6 weeks postoperatively, adjusting for age, years of education, baseline cognition, race, and procedure type. Results Among the 420 allocated subjects who returned for 6-week follow-up (lidocaine: N = 211; placebo: N = 209), there was no difference in the continuous cognitive score change (adjusted mean difference [95% CI], 0.02 (−0.05, 0.08); P = 0.626). Cognitive deficit (greater than 1 SD decline in at least one cognitive domain) at 6 weeks occurred in 41% (87 of 211) in the lidocaine group versus 40% (83 of 209) in the placebo group (adjusted odds ratio [95% CI], 0.94 [0.63, 1.41]; P = 0.766). There were no differences in any quality of life outcomes between treatment groups. At the 1-yr follow-up, there continued to be no difference in cognitive score change, cognitive deficit, or quality of life. Conclusions Intravenous lidocaine administered during and after cardiac surgery did not reduce postoperative cognitive decline at 6 weeks.

BACKGROUND: Many studies have identified racial disparities in healthcare, but few have described disparities in the use of anesthesia modalities. We examined racial disparities in the use of local versus general anesthesia for inguinal hernia repair. We hypothesized that African American and Hispanic patients would be less likely than Caucasians to receive local anesthesia for inguinal hernia repair. MATERIALS AND METHODS: We included 78,766 patients aged ≥18 years in the Veterans Affairs Surgical Quality Improvement Program database who underwent elective, unilateral, open inguinal hernia repair under general or local anesthesia from 1998–2018. We used multiple logistic regression to compare use of local versus general anesthesia and 30-day postoperative complications by race/ethnicity. RESULTS: In total, 17,892 (23%) patients received local anesthesia. Caucasian patients more frequently received local anesthesia (15,009; 24%), compared to African Americans (2353; 17%) and Hispanics (530; 19%), p < 0.05. After adjusting for covariates, we found that African Americans (OR 0.82, 95% CI 0.77–0.86) and Hispanics (OR 0.77, 95% CI 0.69–0.87) were significantly less likely to have hernia surgery under local anesthesia compared to Caucasians. Additionally, local anesthesia was associated with fewer postoperative complications for African American patients (OR 0.46, 95% CI 0.27–0.77). CONCLUSIONS: Although local anesthesia was associated with enhanced recovery for African American patients, they were less likely to have inguinal hernias repaired under local than Caucasians. Addressing this disparity requires a better understanding of how surgeons, anesthesiologists, and patient-related factors may affect the choice of anesthesia modality for hernia repair.

BACKGROUND/OBJECTIVES: Advanced age is associated with increased susceptibility to acute adverse effects of propofol. The present study aimed to describe patterns of propofol dosing for induction of general anesthesia prior to endotracheal intubation in a nationwide sample of older adults presenting for surgery. DESIGN: Retrospective observational study using the Multicenter Perioperative Outcomes Group dataset. SETTING: 36 institutions across the United States. PARTICIPANTS: 350,766 patients over age 65 who received propofol for general anesthetic induction and endotracheal intubation between 2014 and 2018. INTERVENTION: None MEASUREMENTS: Total induction bolus dose of propofol administered. RESULTS: The mean (SD) weight-adjusted propofol dose was 1.7 (0.6) mg/kg. The mean prevalent propofol induction dose exceeded the upper bound of what has been described as the typical geriatric dose requirement across every age category examined. The percent of patients receiving propofol induction doses above the described typical geriatric range was 64.8% (95% CI 64.6-65.0), varying from 73.8% among patients age 65-69 to 45.8% among patients age 80 or over. CONCLUSION. The present study of a large multicenter cohort demonstrates that prevalent propofol dosing commonly falls above the published typically required dose range for patients age ≥ 65 in nationwide anesthetic practice. Widespread variability in induction dose administration remains incompletely explained by known patient variables. The nature and clinical consequences of these unexplained dosing decisions remain important topics for further study. Observed discordance between expected and actual induction dosing raises the question of whether there should be reconsideration of widespread provider practice, or alternatively, whether what is published as the typical propofol induction dose range should be revisited.

Background: Postoperative cognitive dysfunction (POCD), a syndrome of cognitive deficits occurring 1–12 months after surgery primarily in older patients, is associated with poor postoperative outcomes. POCD is hypothesized to result from neuroinflammation; however, the pathways involved remain unclear. Unbiased proteomic analyses have been used to identify neuroinflammatory pathways in multiple neurologic diseases and syndromes but have not yet been applied to POCD. Objective: To utilize unbiased mass spectrometry-based proteomics to identify potential neuroinflammatory pathways underlying POCD. Methods: Unbiased LC-MS/MS proteomics was performed on immunodepleted cerebrospinal fluid (CSF) samples obtained before, 24 hours after, and 6 weeks after major non-cardiac surgery in older adults who did (n = 8) or did not develop POCD (n = 6). Linear mixed models were used to select peptides and proteins with intensity differences for pathway analysis. Results: Mass spectrometry quantified 8,258 peptides from 1,222 proteins in > 50%of patient samples at all three time points. Twelve peptides from 11 proteins showed differences in expression over time between patients with versus without POCD (q

Background Frailty predisposes patients to poor postoperative outcomes. We evaluated whether using local rather than general anesthesia for hernia repair could mitigate effects of frailty. Methods We used the Risk Analysis Index (RAI) to identify 8,038 frail patients in the 1998–2018 Veterans Affairs Surgical Quality Improvement Program database who underwent elective, open unilateral inguinal hernia repair under local or general anesthesia. Our outcome of interest was the incidence of postoperative complications. Results In total, 5,188 (65%) patients received general anesthesia and 2,850 (35%) received local. Local anesthesia was associated with a 48% reduction in complications (OR 0.52, 95%CI 0.38–0.72). Among the frailest patients (RAI≥70), predicted probability of a postoperative complication ranged from 22 to 33% with general anesthesia, compared to 13–21% with local. Conclusions Local anesthesia was associated with a ∼50% reduction in postoperative complications in frail Veterans. Given the paucity of interventions for frail patients, there is an urgent need for a randomized trial comparing effects of anesthesia modality on postoperative complications in this vulnerable population.

BackgroundSome older adults show exaggerated responses to drugs that act on the brain, such as increased delirium risk in response to anticholinergic drugs. The brain’s response to anesthetic drugs is often measured clinically by processed electroencephalogram (EEG) indices. Thus, we developed a processed EEG based-measure of the brain’s neurophysiologic resistance to anesthetic dose-related changes, and hypothesized that it would predict postoperative delirium.MethodsWe defined the Duke Anesthesia Resistance Scale (DARS) as the average BIS index divided by the quantity 2.5 minus the average age-adjusted end-tidal MAC (aaMAC) inhaled anesthetic fraction. The relationship between DARS and postoperative delirium was analyzed in derivation (Duke; N=69), validation (Mt Sinai; N=70), and combined estimation cohorts (N=139) of older surgical patients (age ≥65). In the derivation cohort, we identified a threshold relationship between DARS and for delirium and identified an optimal cut point for prediction.ResultsIn the derivation cohort, the optimal DARS threshold for predicting delirium was 27.0. The delirium rate was 11/49 (22.5%) vs 11/20 (55.0%) and 7/57 (12.3%) vs 6/13 (46.2%) for those with DARS ≥ 27 vs those with DARS < 27 in the derivation and validation cohorts respectively. In the combined estimation cohort, multivariable analysis found a significant association of DARS ConclusionsThese results suggest than an intraoperative processed EEG-based measure of lower brain anesthetic resistance (i.e. DARS

Objective:To determine the relationship between affective measures and cognition before and after non-cardiac surgery in older adults.Methods:Observational prospective cohort study in 103 surgical patients age ≥ 60 years old. All participants underwent cognitive testing, Center for Epidemiologic Studies-Depression, and State Anxiety Inventory screening before and 6 weeks after surgery. Cognitive test scores were combined by factor analysis into 4 cognitive domains, whose mean was defined as the continuous cognitive index (CCI). Postoperative global cognitive change was defined by CCI change from before to after surgery, with negative CCI change indicating worsened postoperative global cognition and vice versa.Results:Lower global cognition before surgery was associated with greater baseline depression severity (Spearman’s r = −0.30, p = 0.002) and baseline anxiety severity (Spearman’s r = −0.25, p = 0.010), and these associations were similar following surgery (r = −0.36, p < 0.001; r = −0.26, p = 0.008, respectively). Neither baseline depression or anxiety severity, nor postoperative changes in depression or anxiety severity, were associated with pre- to postoperative global cognitive change.Conclusions:Greater depression and anxiety severity were each associated with poorer cognitive performance both before and after surgery in older adults. Yet, neither baseline depression or anxiety symptoms, nor postoperative change in these symptoms, were associated with postoperative cognitive change.

Background/objectives Cognitive changes are commonly observed in older adults following surgical procedures. There are concerns that exposure to general anesthesia (GA) may contribute to an increased risk of Alzheimer's disease. Our study examined the associations between exposure to GA compared with regional anesthesia (RA) administered for elective surgical procedures and the development of dementia. Design Population-based propensity matched retrospective cohort study. Setting Linked administrative databases were accessed from ICES (formerly called the Institute for Clinical Evaluative Services) in Ontario, Canada. Participants We included all community-dwelling individuals aged 66 and older who underwent one of five elective surgical procedures in Ontario, Canada, between April 1, 2007, and March 31, 2011. Individuals with evidence of dementia preceding cohort entry were excluded. Individuals who received GA were matched within surgical procedures to those who received RA on age, sex, cohort entry year, and a propensity score to control for potential confounders. Measurements The baseline characteristics of the study sample were compared before and after matching. Individuals were followed for up to 5 years following cohort entry for the occurrence of dementia using a validated algorithm. Cox proportional hazards analysis was used to determine the hazard ratio (HR) and 95% confidence interval (CI) for the association between anesthetic type and dementia. Subgroup and sensitivity analyses were undertaken. Results A total of 7,499 matched pairs were included in the final analysis. Overall, no difference was observed in the risk of being diagnosed with dementia for individuals who received GA when compared with RA (HR = 1.0; 95% CI = .8-1.2). There was also no association between anesthesia and dementia in most subgroup and sensitivity analyses. Conclusion Elective surgery using GA was not associated with an overall elevated risk of dementia when compared with RA. Future studies are required to determine whether surgery is a risk factor for dementia irrespective of anesthetic technique.

BackgroundAPOE4 has been hypothesized to increase Alzheimer’s disease risk by increasing neuroinflammation, though the specific neuroinflammatory pathways involved are unclear.ObjectivesTo characterize CSF proteomic changes as a function of APOE4 copy number.MethodsWe analyzed targeted proteomic data obtained on ADNI CSF samples using a linear regression model adjusting for age, sex, and APOE4 copy number, and a second linear model also adjusting for AD clinical status. False Discovery Rate (FDR) was used to correct for multiple comparisons.ResultsIn the first model, increasing APOE4 copy number was associated with significant expression decreases in a CRP peptide (q=0.006), and significant expression increases in peptides from ALDOA, CH3L1 (YKL-40), and FABPH (qAPOE4 copy number was associated with significant expression decreases in a CRP peptide (q=0.009). In both models, increased APOE4 copy number was associated with trends towards lower expression of all 24 peptides from all 8 different complement proteins measured here, although none of these differences were statistically significant. The odds of this happening by chance for 24 unrelated peptides would be less than 1 in 16 million.ConclusionsIncreasing APOE4 copy number was associated with decreased CSF CRP levels and increased CSF ALDOA, CH3L1 and FABH levels; the CRP decrease remained significant after controlling for AD clinical status. Increased APOE4 copy number may also be associated with decreased CSF complement pathway protein levels, a hypothesis for investigation in future studies.