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Background Perioperative β-blocker therapy has been associated with increased risk of stroke. However, the association between β-blocker initiation before the day of surgery and the risk of stroke is unknown. The authors hypothesized there would be no association between preoperative β-blocker initiation within 60 days of surgery or chronic β-blockade (more than 60 days) and the risk of stroke in patients undergoing major abdominal surgery. Methods Data on elective major abdominal surgery were obtained from the IBM (USA) Truven Health MarketScan 2005 to 2015 Commercial and Medicare Supplemental Databases. Patients were stratified by β-blocker dispensing exposure: (1) β-blocker–naïve, (2) preoperative β-blocker initiation within 60 days of surgery, and (3) chronic β-blocker dispensing (more than 60 days). The authors compared in-hospital stroke and major adverse cardiac events between the different β-blocker therapy exposures. Results There were 204,981 patients who underwent major abdominal surgery. β-Blocker exposure was as follows: perioperative initiation within 60 days of surgery for 4,026 (2.0%) patients, chronic β-blocker therapy for 45,424 (22.2%) patients, and β-blocker–naïve for 155,531 (75.9%) patients. The unadjusted frequency of stroke for patients with β-blocker initiation (0.4%, 17 of 4,026) and chronic β-blocker therapy (0.4%, 171 of 45,424) was greater than in β-blocker–naïve patients (0.2%, 235 of 155,531; P < 0.001). After propensity score weighting, patients initiated on a β-blocker within 60 days of surgery (odds ratio, 0.90; 95% CI, 0.31 to 2.04; P = 0.757) or on chronic β-blocker therapy (odds ratio, 0.86; 95% CI, 0.65 to 1.15; P = 0.901) demonstrated similar stroke risk compared to β-blocker–naïve patients. Patients on chronic β-blocker therapy demonstrated lower adjusted risk of major adverse cardiac events compared to β-blocker–naïve patients (odds ratio, 0.81; 95% CI, 0.72 to 0.91; P = 0.007), despite higher unadjusted absolute event rate (2.6% [1,173 of 45,424] vs. 0.6% [872 of 155,531]). Conclusions Among patients undergoing elective major abdominal surgery, the authors observed no association between preoperative β-blocker initiation within 60 days of surgery or chronic β-blocker therapy and stroke. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Background Preoperative resting echocardiography is often performed before noncardiac surgery, but indications for preoperative resting echocardiography are limited. This study aimed to investigate appropriateness of preoperative resting echocardiography using the Appropriate Use Criteria for Echocardiography, which encompass indications from the guidelines on perioperative cardiovascular evaluation and management and nonperioperative indications independent of the perioperative period. The authors hypothesized that patients are frequently tested without an appropriate indication. Methods Records of patients in the Truven Health MarketScan Commercial and Medicare Supplemental Databases who underwent a major abdominal surgery from 2005 to 2017 were included. These databases contain de-identified records of health services for more than 250 million patients with primary or Medicare supplemental health insurance coverage through employer-based fee-for-service, point-of-service, or capitated plans. Patients were classified based on the presence of an outpatient claim for resting transthoracic echocardiography within 60 days of surgery. Appropriateness was determined via International Classification of Diseases, Ninth Revision–Clinical Modification, and International Classification of Diseases, Tenth Revision–Clinical Modification principal and secondary diagnosis codes associated with the claims, and classified as “appropriate,” “rarely appropriate,” or “unclassifiable” using the Appropriate Use Criteria for Echocardiography. Results Among 230,535 patients in the authors’ cohort, preoperative resting transthoracic echocardiography was performed in 6.0% (13,936) of patients. There were 12,638 (91%) studies classifiable by the Appropriate Use Criteria for Echocardiography, and 1,298 (9%) were unable to be classified. Among the classifiable studies, 8,959 (71%) were deemed “appropriate,” while 3,679 (29%) were deemed “rarely appropriate.” Surveillance of chronic ischemic heart disease and uncomplicated hypertension accounted for 43% (1,588 of 3,679) of “rarely appropriate” echocardiograms. Conclusions More than one in four preoperative resting echocardiograms were considered “rarely appropriate” according to the Appropriate Use Criteria for Echocardiography. A narrow set of patient characteristics accounts for a large proportion of “rarely appropriate” preoperative resting echocardiograms. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Background Awake prone positioning (APP) has been advocated to improve oxygenation and prevent intubations of patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19). This paper aims to synthesize the available evidence on the efficacy of APP.Methods: We performed a systematic review of proportional outcomes from observational studies to compare intubation rate in patients treated with APP or with standard care.Results: A total of 46 published and 4 unpublished observational studies that included 2994 patients were included, of which 921 patients were managed with APP, and 870 patients were managed with usual care. APP was associated with significant improvement of oxygenation parameters in 381 cases of 19 studies that reported this outcome. Among the 41 studies assessing intubation rates (870 patients treated with APP, and 852 patients treated with usual care), the intubation rate was 27%(95%CI, 19 to 37%), as compared to 30%(95%CI, 20 to 42%)(p=0.71), even when duration of application, use of adjunctive respiratory assist device (high flow nasal cannula or non-invasive ventilation) and severity of oxygenation deficit were taken into account. There appeared to be a trend toward improved mortality when treated with APP was compared with usual care (11% v.s. 22%), which was not statistically significant.Conclusions: APP was associated with improvement of oxygenation but did not reduce the intubation rate in patients with acute respiratory failure due to COVID-19. This finding is limited by the high heterogeneity and the observational nature of included studies. Randomized controlled clinical studies are needed to definitively assess whether APP could improve key outcome such as intubation and mortality rate in these patients.

Objectives To develop parsimonious models of in-hospital mortality and morbidity risk after perioperative acute myocardial infarction (AMI). Design Retrospective data analysis. Setting National Inpatient Sample (2008-2013), a 20% sample of all non-federal in-patient hospitalizations in the United States. Participants Patients 45 years or older who experienced perioperative AMI during elective admission for noncardiac surgery. Interventions The study used a mixed principal components analysis and multivariate logistic regression to identify risk factors for in-hospital mortality after perioperative AMI. A model incorporating only preoperative risk factors, defined by the Revised Cardiac Risk Index (RCRI), was compared with a “full risk factor” model, incorporating a large set of preoperative AMI risk factors. The risk of post-AMI disposition to an intermediate care or skilled nursing facility, a marker of functional impairment, then was evaluated. Measurements and Main Results In the present study, 15,574 cases of AMI after elective noncardiac surgery were identified (0.42%, corresponding with 78,122 cases nationally), with a 12.4% in-hospital mortality rate. The “RCRI-only” model was the best-fit model of post-AMI in-hospital mortality risk, without loss of predictive accuracy compared with the “full risk factor” model (area under the receiver operator characteristic curve 0.80, 95% confidence interval [CI] [0.77-0.82] v area under the receiver operator characteristic curve 0.81, 95% CI [0.77-0.83], respectively). Post-AMI mortality risk was the highest for perioperative complications, including sepsis (odds ratio 4.95, 95% CI [4.32-5.67]). Conversely, functional impairment was best predicted by the “full-risk factor” model and depended strongly on chronic preoperative comorbidities. Conclusions The RCRI provides a simple but adequate model of preoperative risk factors for in-hospital mortality after perioperative AMI.

Older adults with an acute burn experience a high frequency of in-hospital mortality. However, traditional burn mortality prediction models are less accurate for older adults likely because they do not account for geriatric specific factors, such as frailty. This study aims to investigate the impact of frailty on in-hospital mortality in older adult burn patients. Patients ≥50 years of age with an acute burn diagnosis in the National Inpatient Sample (2016–2018) were included in the cohort. Three multivariable logistic regression models to predict in-hospital mortality were generated and compared. The models were 1) age and percent total body surface area, 2) age, percent total body surface area and the Elixhauser Comorbidity Index, and 3) age, percent total body surface area, and Hospital Frailty Risk Score. A total of 60,515 weighted discharges were included in the cohort. In-hospital mortality increased with age, as 3.3% of 50- to 64-year-olds, 5.3% of 65- to 74-year-olds, 6.6% of 75- to 84-year-olds, and 9.9% of ≥85-year-olds died during the acute burn admission (P < .001). The multivariable model that included Hospital Frailty Risk Score had a higher area under the receiver operating characteristics curve than the model with age and percent total body surface area (0.84 vs 0.79; P < .001) and the model with Elixhauser Comorbidity Index (0.84 vs 0.83; P = .013). Frailty improved prediction of in-hospital mortality for older adult acute burn patients and burn specialists should consider implementing a frailty instrument to evaluate older adults with an acute burn injury.

BACKGROUND Central line insertion is a core skill for anesthesiologists. Although recent technical advances have increased the safety of central line insertion and reduced the risk of central line-associated infection, noninvasive hemodynamic monitoring and improved intravenous access techniques have also reduced the need for perioperative central venous access. We hypothesized that the number of central lines inserted by anesthesiologists has decreased over the past decade. To test our hypothesis, we reviewed the Medicare Physician Supplier Procedure Summary (PSPS) database from 2007 to 2016. METHODS Claims for central venous catheter placement were identified in the Medicare PSPS database for nontunneled and tunneled central lines. Pulmonary artery catheter insertion was included as a nontunneled line claim. We stratified line insertion claims by specialty for Anesthesiology (including Certified Registered Nurse Anesthetists and Anesthesiology Assistants), Surgery, Radiology, Pulmonary/Critical Care, Emergency Physicians, Internal Medicine, and practitioners who were not anesthesia providers such as Advanced Practice Nurses (APNs) and Physician Assistants (PAs). Utilization rates per 10,000 Medicare beneficiaries were then calculated by specialty and year. Time-based trends were analyzed using Joinpoint linear regression, and the Average Annual Percent Change (AAPC) was calculated. RESULTS Between 2007 and 2016, total claims for central venous catheter insertions of all types decreased from 440.9 to 325.3 claims/10,000 beneficiaries (AAPC = -3.4, 95% confidence interval [CI], -3.6 to -3.2: P < .001). When analyzed by provider specialty and year, the number of nontunneled line insertion claims fell from 43.1 to 15.9 claims/10,000 (AAPC = -7.1; -7.3 to -7.0: P < .001) for surgeons, from 21.3 to 18.5 claims/10,000 (AAPC = -2.5; -2.8 to -2.1: P < .001) for radiologists, and from 117.4 to 72.7 claims/10,000 (AAPC = -5.2; 95% CI, -6.3 to -4.0: P < .001) for anesthesia providers. In contrast, line insertions increased from 18.2 to 26.0 claims/10,000 (AAPC = 3.2; 2.3-4.2: P < .001) for Emergency Physicians and from 3.2 to 9.3 claims/10,000 (AAPC = 6.0; 5.1-6.9: P < .001) for PAs and APNs who were not anesthesia providers. Among anesthesia providers, the share of line claims made by nurse anesthetists increased by 14.5% over the time period. CONCLUSIONS We observed a 38.3% decrease in claims for nontunneled central lines placed by anesthesiologists from 2007 to 2016. These findings have implications for anesthesiology resident training and maintenance of competence among practicing clinicians. Further research is needed to clarify the effect of decreasing line insertion numbers on line insertion competence among anesthesiologists.

BACKGROUND: Frailty and cognitive impairment are associated with postoperative delirium but are rarely assessed preoperatively. The study was designed to test the hypothesis that preoperative screening for frailty or cognitive impairment identifies patients at risk for postoperative delirium (primary outcome). METHODS: In this prospective cohort study, we administered frailty and cognitive screening instruments to 229 patients ≥ 70 years old presenting for elective spine surgery. Screening for frailty (5-item FRAIL scale) and cognition (Mini-Cog, Animal Verbal Fluency) were performed at the time of the preoperative evaluation. Demographic data, perioperative variables, and postoperative outcomes were gathered. Delirium was the primary outcome detected by either the Confusion Assessment Method, assessed daily from postoperative day 1 to 3 or until discharge, if patient was discharged sooner, or comprehensive chart review. Secondary outcomes were all other-cause complications, discharge not to home, and hospital length of stay. RESULTS: The cohort was 75 [73 to 79 years] years of age, 124/219 (57%) were male. Many scored positive for pre-frailty (117/218; 54%), frailty (53/218; 24%), and cognitive impairment (50 – 82/219; 23–37%). Fifty-five patients (25%) developed delirium postoperatively. On multivariable analysis, frailty (scores 3 to 5) (OR 6.6; 95% CI 1.96 to 21.9; P = 0.002) versus robust (score 0) on the FRAIL scale, lower animal fluency scores (OR 1.08; 95% CI 1.01 to1.51; P = 0.036) for each point decrease in the number of animals named, and more invasive surgical procedures (OR 2.69; 95% CI 1.31 to 5.50; P = 0.007) versus less invasive procedures were associated with postoperative delirium. CONCLUSIONS: Screening for frailty and cognitive impairment preoperatively using the FRAIL scale and the Animal Verbal Fluency test in older elective spine surgery patients identifies those at high risk for the development of postoperative delirium.

Introduction Older adults experience a disproportionately higher rate of hospitalization and mortality due to burns. However, national estimates of in-hospital mortality in geriatric patients with acute burns outside of the recognized burn centers are lacking. The purpose of this study is to characterize such national estimates and identify the prognostic factors associated with in-hospital mortality in elderly patients with acute burn injuries. Methods Patients ≥50 years with an acute burn diagnosis in the United States National Inpatient Sample from 2016 to 2018 were identified by using International Classification of Diseases, Tenth Revision, Clinical Modification codes (T20.0-T31; initial encounters only). Trend weights were used from the Agency for Healthcare Research and Quality to generate national estimates. Factors associated with in-hospital mortality were evaluated by multivariable logistic regression. Results A total of 60,515 weighted discharges met inclusion criteria. For age groups 50-64 (reference category), 65-74, 75-84, and ≥85, the numbers of discharges were 33,100, 15,295, 7,880, and 4,240, respectively; the in-hospital mortality rates were 3.3%, 5.3%, 6.6%, and 9.9%, respectively. The full list of significant variables of the multivariable regression can be seen in Table 1. Specifically, variables associated with increased in-hospital mortality include age 75-84 (odds ratio [OR], 3.91; p< 0.001), age ≥85 years (OR, 11.94; p< 0.001), total body surface area (%TBSA) 10-19% (OR, 2.93; p=0.017), and %TBSA ≥20% (OR, 27.78; p< 0.001). Intentional burns were associated with an increased risk of mortality (OR, 7.86; p=0.005), whereas hot liquids and vapor burns were associated with a decreased risk of mortality (OR, 0.33; p=0.043). Respiratory distress/failure (OR, 5.78; p< 0.001), aspiration pneumonia/pneumonitis (OR, 5.01; p=0.004), shock (OR, 4.58; p=0.004), and acute renal failure (OR, 2.85; p=0.005) were associated with an increased risk of mortality. One or more surgical excisions were associated with a reduced risk of mortality (OR, 0.26; p< 0.001). Conclusions Age ≥75 years, %TBSA ≥10%, intentional burn as the mechanism of injury, and certain comorbidities and complications were significant risk factors for in-hospital mortality in geriatric burn patients.

Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Functional capacity assessment is a core component of current perioperative cardiovascular evaluation and management guidelines for noncardiac surgery. The authors investigated the ability of standardized physical function questions to predict whether participants engaged in moderate physical activity as measured by hip accelerometers. Methods Participant responses to physical functioning questions and whether they engaged in moderate physical activity were extracted from the National Health and Nutrition Examination Survey (2003 to 2004 and 2005 to 2006). Physical activity intensity was measured using hip accelerometers. Adult participants with at least one Revised Cardiac Risk Index condition were included in the analysis. Standardized physical function questions were evaluated using a classification and regression tree analysis. Training and test datasets were randomly generated to create and test the analysis. Results Five hundred and twenty-two participants were asked the physical functioning questions and 378 of 522 (72.4%) had a bout of moderate-vigorous activity. Classification and regression tree analysis identified a “no difficulty” response to walking up 10 stairs and the ability to walk two to three blocks as the most sensitive questions to predict the presence of a 2-min bout of moderate activity. Participants with positive responses to both questions had a positive likelihood ratio of 3.7 and a posttest probability greater than 90% of a 2-min bout of moderate-vigorous activity. The sensitivity and specificity of positive responses to physical functioning questions in the pruned tree were 0.97 (95% CI, 0.94 to 0.98) and 0.16 (95% CI, 0.10 to 0.23) for training data, and 0.88 (95% CI, 0.75 to 0.96) and 0.10 (95% CI, 0.00 to 0.45) for the test data. Participants with at least one 2-min bout of moderate activity had a greater percentage of overall daily active time (35.4 ± 0.5 vs. 26.7 ± 1.2; P = 0.001) than those without. Conclusions Standardized physical function questions are highly sensitive but poorly specific to identify patients who achieve moderate physical activity. Additional strategies to evaluate functional capacity should be considered.

BACKGROUND Functional capacity assessment plays a core role in the preoperative evaluation. The Duke Activity Status Index (DASI) and the 6-minute walk test (6MWT) are 2 methods that have demonstrated the ability to evaluate functional capacity and predict perioperative outcomes. Smartphones offer a novel method to facilitate functional capacity assessment as they can easily administer a survey and accelerometers can track patient activity during a 6MWT. We developed a smartphone application to administer a 6MWT and DASI survey and performed a pilot study to evaluate the accuracy of a smartphone-based functional capacity tool in our Anesthesia and Perioperative Medicine Clinic. METHODS Using the Apple ResearchKit software platform, we developed an application that administers a DASI survey and 6MWT on an iOS smartphone. The DASI was presented to the patient 1 question on the screen at a time and the application calculated the DASI score and estimated peak oxygen uptake (VO2). The 6MWT used the CMPedometer class from Apple's core motion facility to retrieve accelerometer data collected from the device's motion coprocessor to estimate steps walked. Smartphone estimated steps were compared to a research-grade pedometer using the intraclass correlation coefficient (ICC). Distance walked was directly measured during the 6MWT and we performed a multivariable linear regression with biometric variables to create a distance estimation algorithm to estimate distance walked from the number of steps recorded by the application. RESULTS Seventy-eight patients were enrolled in the study and completed the protocol. Steps measured by the smartphone application as compared to the pedometer demonstrated moderate agreement with an ICC (95% CI) of 0.87 (0.79-0.92; P = .0001). The variables in the distance estimation algorithm included (β coefficient [slope], 95% CI) steps walked (0.43, 0.29-0.57; P < .001), stride length (0.38, 0.22-0.53; P < .001), age in years (-1.90, -3.06 to -0.75; P = .002), and body mass index (-2.59, -5.13 to -0.06; P = .045). The overall model fit was R = 0.72, which indicates a moderate level of goodness of fit and explains 72% of the variation of distance walked during a 6MWT. CONCLUSIONS Our pilot study demonstrated that a smartphone-based functional capacity assessment is feasible using the DASI and 6MWT. The DASI was easily completed by patients and the application clearly presented the results of the DASI to providers. Our application measured steps walked during a 6MWT moderately well in a preoperative patient population; however, future studies are needed to improve the smartphone application's step-counting accuracy and distance estimation algorithm.

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BACKGROUND: The United States population is aging and projected to undergo an increasing number of general surgical procedures. However, recent trends in the frequency of major abdominal procedures in older adults are currently unknown as improvements in non-operative interventions may obviate the need for major surgery. Thus, we evaluated the trends of major abdominal surgical procedures in older adults in the United States. METHODS: We performed a retrospective cohort study using the National Inpatient Sample from 2002–2014 with trend analysis using National Cancer Institute’s Joinpoint Trend Analysis Software. We identified the average annual percent change (AAPC) in yearly frequency of major abdominal surgical procedures in older adults (≥50 years of age). RESULTS: Our cohort included a total of 3,951,947 survey-weighted discharges that included a major abdominal surgery in adults ≥50 years of age between 2002 and 2014. Of these discharges, 2,529,507 (64.0%) were for elective abdominal surgeries, 2,062,835 (52.0%) were for female patients, and mean (SD) age was 61.4(15.9) years. The frequency of major abdominal procedures (elective and emergent) decreased for adults age 65–74 (AAPC: −1.43, −1.75, −1.11, P85 (AAPC= −3.53; −4.57, −2.48: P

Background: Awake prone positioning (APP) has been advocated to improve oxygenation and prevent intubations of patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19). This paper aims to synthesize the available evidence on the efficacy of APP. Methods: We performed a prospective systematic review and meta-analysis of observational studies to compare in-hospital intubation and mortality rates in patients treated with APP or with standard care.Results: A total of 46 published and 4 unpublished observational studies that included 2994 patients were included. The intubation rate was 27% (95%CI, 19 to 37%) in the 870 patients treated with APP, as compared to 30% (95%CI, 20 to 42%) in the 852 patients treated with usual care (p=0.71). The mortality rate was 11% (95CI%, 6 to 20%) in the 767 patients treated with APP, as compared to 22% (95%CI, 13 to 36%) in those treated with usual care. This difference was not statistically significant (p=0.10). APP was associated with significant improvement of various oxygenation parameters in 19 studies (n=381) that reported this outcome.Conclusions: In this prospective meta-analysis of observational studies of patients with acute hypoxemic respiratory failure due to COVID-19, APP did not result in lower intubation or mortality rates, despite reported improvements in oxygenation parameters. Data from randomized controlled trials are needed. Routine implementation of APP outside of a clinical trial is not supported by current evidence. Registered on PROSPERO on August 3d, 2020, CRD42020201947.

IMPORTANCE: Cardiac stress testing is often performed prior to noncardiac surgery, although trends in use of preoperative stress testing and the effect of testing on cardiovascular outcomes are currently unknown. OBJECTIVE: To describe temporal trends and outcomes of preoperative cardiac stress testing from 2004 to 2017. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study of patients undergoing elective total hip or total knee arthroplasty from 2004 to 2017. Trend analysis was conducted using Joinpoint and generalized estimating equation regression. The study searched IBM MarketScan Research Databases inpatient and outpatient health care claims for private insurers including supplemental Medicare coverage and included patients with a claim indicating an elective total hip or total knee arthroplasty from January 1, 2004, to December 31, 2017. EXPOSURES: Elective total hip or knee arthroplasty. MAIN OUTCOMES AND MEASURES: Trend in yearly frequency of preoperative cardiac stress testing. RESULTS: The study cohort consisted of 801 396 elective total hip (27.9%; n = 246 168 of 801 396) and total knee (72.1%; 555 228 of 801 396) arthroplasty procedures, with a median age of 62 years (interquartile range, 57-70 years) and 58.1% women (n = 465 545 of 801 396). The overall rate of stress testing during the study period was 10.4% (n = 83 307 of 801 396). The rate of stress tests increased 0.65% (95% CI, 0.09-1.21; P = .03) annually from quarter (Q) 1 of 2004 until Q2 of 2006. A joinpoint was identified at Q3 of 2006 (95% CI, 2005 Q4 to 2007 Q4) when preoperative stress test use decreased by −0.71% (95% CI, −0.79% to 0.63%; P

BACKGROUND: Ischemic optic neuropathy (ION) is a rare complication of anesthesia and surgery that causes vision loss in spine fusion. We sought to develop a predictive model based upon known pre-operative risk factors for perioperative ION to guide patient and physician pre-operative decision-making. METHODS: In the National Inpatient Sample (NIS) for 1998–2012, discharges for posterior thoracic, lumbar, and sacral spine fusion were identified and classified by ION status. Variables were selected without weighting via variable clustering using Principal Component Analysis of Mixed Data (PCA-MIX). Hierarchical clustering with four clusters was performed, and the variable with largest squared loading in each cluster was chosen. By splitting our sample into a training and testing data set, we developed and internally validated a predictive model. The final model using variables known pre-operatively was constructed to allow determination of relative and absolute risk of developing perioperative ION, and was tested for calibration and discrimination. RESULTS: The final predictive model based upon hierarchical clustering contained three pre-operative factors, age, male or female sex, and the presence of obstructive sleep apnea (OSA). The predictive model based upon these factors had an area under the receiver operating characteristic curve of 0.65 and good calibration. A score cutoff of > 1 had 100% sensitivity, while score of 3 had 96.5% specificity. The highest estimated absolute risk (844.5/million) and relative risk of ION (46.40) was for a male, age 40–64, with OSA. CONCLUSIONS: The predictive model could enable screening for patients at higher risk of ION in order to provide more accurate risk assessment and surgical and anesthetic planning for perioperative ION in spine fusion.

BACKGROUND Retinal artery occlusion (RAO) is a rare but devastating complication of spinal fusion surgery. We aimed to determine its incidence and associated risk factors. METHODS Hospitalizations involving spinal fusion surgery were identified by searching the National Inpatient Sample, a database of hospital discharges, from 1998 to 2013. RAO cases were identified using ICD-9-CM codes. Using the STROBE guidelines, postulated risk factors were chosen based on literature review and identified using ICD-9-CM codes. Multivariate logistic models with RAO as outcome, and risk factors, race, age, admission, and surgery type evaluated associations. RESULTS Of an estimated 4,784,275 spine fusions in the United States from 1998 to 2013, there were 363 (CI: 291-460) instances of RAO (0.76/10,000 spine fusions, CI: 0.61-0.96). Incidence ranged from 0.35/10,000 (CI: 0.11-1.73) in 2001-2002 to 1.29 (CI: 0.85-2.08) in 2012-2013, with no significant trend over time (P = 0.39). Most strongly associated with RAO were stroke, unidentified type (odds ratio, OR: 14.33, CI: 4.54-45.28, P < 0.001), diabetic retinopathy (DR) (OR: 7.00, CI: 1.18-41.66, P = 0.032), carotid stenosis (OR: 4.94, CI: 1.22-19.94, P = 0.025), aging (OR for age 71-80 years vs 41-50 years referent: 4.07, CI: 1.69-10.84, P = 0.002), and hyperlipidemia (OR: 2.96, CI: 1.85-4.73, P < 0.001). There was an association between RAO and transforaminal lumbar interbody fusion (OR: 2.95, CI: 1.29-6.75, P = 0.010). RAO was more likely to occur with spinal surgery performed urgently or emergently compared with being done electively (OR: 0.40, CI: 0.23-0.68, P < 0.001). CONCLUSIONS Patient-specific associations with RAO in spinal fusion include aging, carotid stenosis, DR, hyperlipidemia, stroke, and specific types of surgery. DR may serve as an observable biomarker of heightened risk of RAO in patients undergoing spine fusion.

The American Society of Regional Anesthesia and Pain Medicine's Third Practice Advisory on local anesthetic systemic toxicity is an interim update from its 2010 advisory. The advisory focuses on new information regarding the mechanisms of lipid resuscitation, updated frequency estimates, the preventative role of ultrasound guidance, changes to case presentation patterns, and limited information related to local infiltration anesthesia and liposomal bupivacaine. In addition to emerging information, the advisory updates recommendations pertaining to prevention, recognition, and treatment of local anesthetic systemic toxicity. WHAT'S NEW IN THIS UPDATE?: This interim update summarizes recent scientific findings that have enhanced our understanding of the mechanisms that lead to lipid emulsion reversal of LAST, including rapid partitioning, direct inotropy, and post-conditioning. Since the previous practice advisory, epidemiological data have emerged that suggest a lower frequency of LAST as reported by single institutions and some registries, nevertheless a considerable number of events still occur within the general community. Contemporary case reports suggest a trend toward delayed presentation, which may mirror the increased use of ultrasound guidance (fewer intravascular injections), local infiltration techniques (slower systemic uptake), and continuous local anesthetic infusions. Small patient size and sarcopenia are additional factors that increase potential risk for LAST. An increasing number of reported events occur outside of the traditional hospital setting and involve non-anesthesiologists.

Background Ischemic optic neuropathy is the most common form of perioperative visual loss, with highest incidence in cardiac and spinal fusion surgery. To date, potential risk factors have been identified in cardiac surgery by only small, single-institution studies. To determine the preoperative risk factors for ischemic optic neuropathy, the authors used the National Inpatient Sample, a database of inpatient discharges for nonfederal hospitals in the United States. Methods Adults aged 18 yr or older admitted for coronary artery bypass grafting, heart valve repair or replacement surgery, or left ventricular assist device insertion in National Inpatient Sample from 1998 to 2013 were included. Risk of ischemic optic neuropathy was evaluated by multivariable logistic regression. Results A total of 5,559,395 discharges met inclusion criteria with 794 (0.014%) cases of ischemic optic neuropathy. The average yearly incidence was 1.43 of 10,000 cardiac procedures, with no change during the study period (P = 0.57). Conditions increasing risk were carotid artery stenosis (odds ratio, 2.70), stroke (odds ratio, 3.43), diabetic retinopathy (odds ratio, 3.83), hypertensive retinopathy (odds ratio, 30.09), macular degeneration (odds ratio, 4.50), glaucoma (odds ratio, 2.68), and cataract (odds ratio, 5.62). Female sex (odds ratio, 0.59) and uncomplicated diabetes mellitus type 2 (odds ratio, 0.51) decreased risk. Conclusions The incidence of ischemic optic neuropathy in cardiac surgery did not change during the study period. Development of ischemic optic neuropathy after cardiac surgery is associated with carotid artery stenosis, stroke, and degenerative eye conditions.

Purpose To study the incidence and risk factors for retinal artery occlusion (RAO) in cardiac surgery. Design Retrospective study using the National Inpatient Sample (NIS). Methods The NIS was searched for cardiac surgery. Retinal artery occlusion was identified by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Postulated risk factors based on literature review were included in multivariate logistic models. Main Outcome Measures Diagnosis of RAO. Results A total of 5 872 833 cardiac operative procedures were estimated in the United States from 1998 to 2013, with 4564 RAO cases (95% confidence interval [95% CI], 4282–4869). Nationally estimated RAO incidence was 7.77/10 000 cardiac operative procedures from 1998 to 2013 (95% CI, 7.29–8.29). Associated with increased RAO were giant cell arteritis (odds ratio [OR], 7.73; CI, 2.78–21.52; P P P P P P = 0.002), diabetes mellitus (DM) with ophthalmic complications (OR, 1.89; CI, 1.10–3.24; P = 0.02), and aortic insufficiency (OR, 1.85; CI, 1.26–2.71; P = 0.002). Perioperative bleeding, aortic and mitral valve surgery, and septal surgery increased the odds of RAO. Negatively associated with RAO were female gender (OR, 0.77; CI, 0.66–0.89; P P = 0.049), acute coronary syndrome (OR, 0.72; CI, 0.58–0.89; P = 0.003), atrial fibrillation (OR, 0.82; CI, 0.70–0.95; P = 0.01), congestive heart failure (OR, 0.73; CI, 0.60–0.88; P P = 0.001), and smoking (OR, 0.82; CI, 0.70–0.97; P = 0.02). Conclusions Risk factors for RAO in cardiac surgery include giant cell arteritis, carotid stenosis, stroke, hypercoagulable state, and DM with ophthalmic complications; associated with lower risk were female gender, thrombocytopenia, acute coronary syndrome, atrial fibrillation, congestive heart failure, DM 2, and smoking. Surgery in which the heart was opened (e.g., septal repair) versus surgery in which it was not (e.g., CABG) and perioperative bleeding increased the risk of RAO.

BACKGROUND: Big data clinical research involves application of large data sets to the study of disease. It is of interest to neuro-ophthalmologists but also a challenge because of the relative rarity of many of the diseases treated limit prospective investigation. EVIDENCE ACQUISITION: Evidence for this review was gathered from the authors’ experiences performing analysis of large data sets and review of the literature. RESULTS: Big data sets are heterogenous including prospective surveys, medical administrative and claims data and registries compiled from medical records. High quality studies must pay careful attention to data set selection including bias, data management including missing data, variable definition and statistical modeling in order to generate appropriate conclusions. There are many studies of neuro-ophthalmic diseases that utilize big data approaches. CONCLUSIONS: Big data clinical research studies complement other research methodologies to advance understanding of human disease. A rigorous and careful approach to data set selection, data management, data analysis and data interpretation characterizes high quality studies.

Background Perioperative ischemic optic neuropathy (ION) causes visual loss in spinal fusion. Previous case–control studies are limited by study size and lack of a random sample. The purpose of this study was to study trends in ION incidence in spinal fusion and risk factors in a large nationwide administrative hospital database. Methods In the Nationwide Inpatient Sample for 1998 to 2012, procedure codes for posterior thoracic, lumbar, or sacral spine fusion and diagnostic codes for ION were identified. ION was studied over five 3-yr periods (1998 to 2000, 2001 to 2003, 2004 to 2006, 2007 to 2009, and 2010 to 2012). National estimates were obtained using trend weights in a statistical survey procedure. Univariate and Poisson logistic regression assessed trends and risk factors. Results The nationally estimated volume of thoracic, lumbar, and sacral spinal fusion from 1998 to 2012 was 2,511,073. ION was estimated to develop in 257 patients (1.02/10,000). The incidence rate ratio (IRR) for ION significantly decreased between 1998 and 2012 (IRR, 0.72 per 3 yr; 95% CI, 0.58 to 0.88; P = 0.002). There was no significant change in the incidence of retinal artery occlusion. Factors significantly associated with ION were age (IRR, 1.24 per 10 yr of age; 95% CI, 1.05 to 1.45; P = 0.009), transfusion (IRR, 2.72; 95% CI, 1.38 to 5.37; P = 0.004), and obesity (IRR, 2.49; 95% CI, 1.09 to 5.66; P = 0.030). Female sex was protective (IRR, 0.30; 95% CI, 0.16 to 0.56; P = 0.0002). Conclusions Perioperative ION in spinal fusion significantly decreased from 1998 to 2012 by about 2.7-fold. Aging, male sex, transfusion, and obesity significantly increased the risk.

Background Local anesthetic systemic toxicity (LAST) is a rare and potentially devastating complication of regional anesthesia. Single-institution registries have reported a decreasing incidence, but these results have limited broad applicability. A recent study using a US database found a relatively high incidence of LAST. We used the National Inpatient Sample, a US database of inpatient admissions, to identify the national incidence and associated risk factors for LAST in total joint arthroplasties. Methods In this retrospective study, we studied patients undergoing hip, knee, or shoulder arthroplasty, from 1998 to 2013, with an adjunct peripheral nerve blockade. We used a multivariable logistic regression to identify patient conditions, hospital level variables, and procedure sites associated with LAST. Results A total of 710,327 discharges met inclusion criteria. The average adjusted incidence was 1.04 per 1000 peripheral nerve blocks, with decreasing trend over the 15-year study period (odds ratio [OR], 0.90; P = 0.002). Shoulder arthroplasty (OR, 4.35; P = 0.0001) compared with knee or hip arthroplasty and medium-size (OR, 3.34; P = 0.003) and large-size (OR, 2.40; P = 0.025) hospitals as compared with small hospitals were associated with increased odds of LAST. Conclusions The incidence of LAST nationally in total joint arthroplasty with adjunct nerve blocks is similar to recent estimates from academic centers, with a small decreasing trend through the study period. Despite an overall low incidence rate, practitioners should continue to maintain vigilance for manifestations of LAST, especially as the use of regional anesthesia continues to increase.

Ischemic optic neuropathy is the most common form of perioperative visual loss, with highest incidence in cardiac and spinal fusion surgery. To date, potential risk factors have been identified in cardiac surgery by only small, single-institution studies. To determine the preoperative risk factors for ischemic optic neuropathy, the authors used the National Inpatient Sample, a database of inpatient discharges for nonfederal hospitals in the United States.Adults aged 18 yr or older admitted for coronary artery bypass grafting, heart valve repair or replacement surgery, or left ventricular assist device insertion in National Inpatient Sample from 1998 to 2013 were included. Risk of ischemic optic neuropathy was evaluated by multivariable logistic regression.A total of 5,559,395 discharges met inclusion criteria with 794 (0.014%) cases of ischemic optic neuropathy. The average yearly incidence was 1.43 of 10,000 cardiac procedures, with no change during the study period (P = 0.57). Conditions increasing risk were carotid artery stenosis (odds ratio, 2.70), stroke (odds ratio, 3.43), diabetic retinopathy (odds ratio, 3.83), hypertensive retinopathy (odds ratio, 30.09), macular degeneration (odds ratio, 4.50), glaucoma (odds ratio, 2.68), and cataract (odds ratio, 5.62). Female sex (odds ratio, 0.59) and uncomplicated diabetes mellitus type 2 (odds ratio, 0.51) decreased risk.The incidence of ischemic optic neuropathy in cardiac surgery did not change during the study period. Development of ischemic optic neuropathy after cardiac surgery is associated with carotid artery stenosis, stroke, and degenerative eye conditions.

Perioperative ischemic optic neuropathy (ION) causes visual loss in spinal fusion. Previous case-control studies are limited by study size and lack of a random sample. The purpose of this study was to study trends in ION incidence in spinal fusion and risk factors in a large nationwide administrative hospital database.In the Nationwide Inpatient Sample for 1998 to 2012, procedure codes for posterior thoracic, lumbar, or sacral spine fusion and diagnostic codes for ION were identified. ION was studied over five 3-yr periods (1998 to 2000, 2001 to 2003, 2004 to 2006, 2007 to 2009, and 2010 to 2012). National estimates were obtained using trend weights in a statistical survey procedure. Univariate and Poisson logistic regression assessed trends and risk factors.The nationally estimated volume of thoracic, lumbar, and sacral spinal fusion from 1998 to 2012 was 2,511,073. ION was estimated to develop in 257 patients (1.02/10,000). The incidence rate ratio (IRR) for ION significantly decreased between 1998 and 2012 (IRR, 0.72 per 3 yr; 95% CI, 0.58 to 0.88; P = 0.002). There was no significant change in the incidence of retinal artery occlusion. Factors significantly associated with ION were age (IRR, 1.24 per 10 yr of age; 95% CI, 1.05 to 1.45; P = 0.009), transfusion (IRR, 2.72; 95% CI, 1.38 to 5.37; P = 0.004), and obesity (IRR, 2.49; 95% CI, 1.09 to 5.66; P = 0.030). Female sex was protective (IRR, 0.30; 95% CI, 0.16 to 0.56; P = 0.0002).Perioperative ION in spinal fusion significantly decreased from 1998 to 2012 by about 2.7-fold. Aging, male sex, transfusion, and obesity significantly increased the risk.