Association Between Child Access Prevention and State Firearm Laws With Pediatric Firearm-Related Deaths.

INTRODUCTION: We aim to study the association between state child access prevention (CAP) and overall firearm laws with pediatric firearm-related mortality. METHODS: The Centers for Disease Control and Prevention Web-based Injury Statistics Query and Reporting System was queried for pediatric (aged < 18 y) all-intent (accidental, suicide, and homicide) firearm-related crude death rates (CDRs) among the 50 states from 1999 to 2019. States were into three groups: Always CAP (throughout the 20-year period), Never CAP, and New CAP (enacted CAP during study period). We used the Giffords Law Center Annual Gun Law Scorecard (A, B, C, D, F) to group states into strict (A, B) and lenient (C, D, F) firearm laws. A scatter plot was constructed to display state CDR based on CAP laws by year. The top 10 states by CDR per year were tabulated based on CAP law status. Wilcoxon rank-sum was used to compare CDR between strict and lenient scorecard states in 2019. RESULTS: There were 12 Always CAP, 21 Never CAP, and 17 New CAP states from 1999 to 2019. No states changed from CAP laws to no CAP laws. Never CAP and New CAP states dominated the high outliers in CDR compared to Always CAP. The top 10 states with the highest CDR per year were most commonly Never CAP. Strict firearm laws states had lower median CDR in 2019 than lenient states (0.79 [0-1.67] versus 2.59 [1.66-3.53], P = 0.007). CONCLUSIONS: Stricter overall gun laws are associated with three-fold lower all-intent pediatric firearm-related deaths. For 2 decades, the 10 states with the highest CDR were almost universally those without CAP laws. Our findings support the RAND Gun Policy in America initiative's claims on the importance of CAP laws in reducing suicide, unintentional deaths, and violent crime among children, but more research is needed.

A Prospective Multicenter Comparison of Trauma and Injury Severity Score, American Society of Anesthesiologists Physical Status, and National Surgical Quality Improvement Program Calculator's Ability to Predict Operative Trauma Outcomes.

BACKGROUND: Trauma outcome prediction models have traditionally relied upon patient injury and physiologic data (eg, Trauma and Injury Severity Score [TRISS]) without accounting for comorbidities. We sought to prospectively evaluate the role of the American Society of Anesthesiologists physical status (ASA-PS) score and the National Surgical Quality Improvement Program Surgical Risk-Calculator (NSQIP-SRC), which are measurements of comorbidities, in the prediction of trauma outcomes, hypothesizing that they will improve the predictive ability for mortality, hospital length of stay (LOS), and complications compared to TRISS alone in trauma patients undergoing surgery within 24 hours. METHODS: A prospective, observational multicenter study (9/2018-2/2020) of trauma patients ≥18 years undergoing operation within 24 hours of admission was performed. Multiple logistic regression was used to create models predicting mortality utilizing the variables within TRISS, ASA-PS, and NSQIP-SRC, respectively. Linear regression was used to create models predicting LOS and negative binomial regression to create models predicting complications. RESULTS: From 4 level I trauma centers, 1213 patients were included. The Brier Score for each model predicting mortality was found to improve accuracy in the following order: 0.0370 for ASA-PS, 0.0355 for NSQIP-SRC, 0.0301 for TRISS, 0.0291 for TRISS+ASA-PS, and 0.0234 for TRISS+NSQIP-SRC. However, when comparing TRISS alone to TRISS+ASA-PS (P = .082) and TRISS+NSQIP-SRC (P = .394), there was no significant improvement in mortality prediction. NSQIP-SRC more accurately predicted both LOS and complications compared to TRISS and ASA-PS. CONCLUSIONS: TRISS predicts mortality better than ASA-PS and NSQIP-SRC in trauma patients undergoing surgery within 24 hours. The TRISS mortality predictive ability is not improved when combined with ASA-PS or NSQIP-SRC. However, NSQIP-SRC was the most accurate predictor of LOS and complications.

Microbial Epidemiology of Acute and Perforated Appendicitis: A Post-Hoc Analysis of an EAST Multicenter Study.

BACKGROUND: There are significant practice variations in antibiotic treatment for appendicitis, ranging from short-course narrow spectrum to long-course broad-spectrum. We sought to describe the modern microbial epidemiology of acute and perforated appendicitis in adults to help inform appropriate empiric coverage and support antibiotic stewardship initiatives. METHODS: This is a post-hoc secondary analysis of the Multicenter Study of the Treatment of Appendicitis in America: Acute, Perforated, and Gangrenous (MUSTANG) which prospectively enrolled adult patients (age ≥ 18 years) diagnosed with appendicitis between January 2017 and June 2018 across 28 centers in the United States. We included all subjects with positive microbiologic cultures during primary or secondary (rescue after medical failure) appendectomy or percutaneous drainage. Culture yield was compared between low- and high-grade appendicitis as per the AAST classification. RESULTS: A total of 3,471 patients were included: 230 (7%) had cultures performed, and 179/230 (78%) had positive results. Cultures were less likely to be positive in grade 1 compared to grades 3, 4, or 5 appendicitis with 2/18 (11%) vs 61/70 (87%) (p < .001). Only 1 subject had grade 2 appendicitis and culture results were negative. E. coli was the most common pathogen and cultured in 29 (46%) of primary appendectomy samples, 16 (50%) of secondary, and 44 (52%) of percutaneous drainage samples. CONCLUSION: Culturing low-grade appendicitis is low yield. E. coli is the most commonly cultured microbe in acute and perforated appendicitis. This data helps inform empiric coverage for both antibiotics alone and as an adjunct to operative or percutaneous intervention.

Incidence, Risk Factors, and Clinical Consequence of Enteral Feeding Intolerance in the Mechanically Ventilated Critically Ill: An Analysis of a Multicenter, Multiyear Database.

OBJECTIVES: To determine the incidence of enteral feed intolerance, identify factors associated with enteral feed intolerance, and assess the relationship between enteral feed intolerance and key nutritional and clinical outcomes in critically ill patients. DESIGN: Analysis of International Nutrition Survey database collected prospectively from 2007 to 2014. SETTING: Seven-hundred eighty-five ICUs from around the world. PATIENTS: Mechanically ventilated adults with ICU stay greater than or equal to 72 hours and received enteral nutrition during the first 12 ICU days. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: We defined enteral feed intolerance as interrupted feeding due to one of the following reasons: high gastric residual volumes, increased abdominal girth, distension, subjective discomfort, emesis, or diarrhea. The current analysis included 15,918 patients. Of these, 4,036 (24%) had at least one episode of enteral feed intolerance. The enteral feed intolerance rate increased from 1% on day 1 to 6% on days 4 and 5 and declined daily thereafter. After controlling for site and patient covariates, burn (odds ratio 1.46; 95% CIs, 1.07-1.99), gastrointestinal (odds ratio 1.45; 95% CI, 1.27-1.66), and sepsis (odds ratio 1.34; 95% CI, 1.17-1.54) admission diagnoses were more likely to develop enteral feed intolerance, as compared to patients with respiratory-related admission diagnosis. enteral feed intolerance patients received about 10% less enteral nutrition intake, as compared to patients without enteral feed intolerance after controlling for important covariates including severity of illness. Enteral feed intolerance patients had fewer ventilator-free days and longer ICU length of stay time to discharge alive (all p < 0.0001). The daily mortality hazard rate increased by a factor of 1.5 (1.4-1.6; p < 0.0001) once enteral feed intolerance occurred. CONCLUSIONS: Enteral feed intolerance occurs frequently during enteral nutrition delivery in the critically ill. Burn and gastrointestinal patients had the highest risk of developing enteral feed intolerance. Enteral feed intolerance is associated with lower enteral nutrition delivery and worse clinical outcomes. Identification, prevention, and optimal management of enteral feed intolerance may improve nutrition delivery and clinical outcomes in important "at risk" populations.

Discordance in Appendicitis Grading and the Association with Outcomes: A Post-Hoc Analysis of an EAST Multicenter Study.

BACKGROUND: The American Association for the Surgery of Trauma (AAST) appendicitis severity grading criteria use independent subscales for radiologists (Rad), surgeons (Surg), and pathologists (Path). We reviewed the EAST Multicenter Study of the Treatment of Appendicitis in America: Acute, Perforated, and Gangrenous (MUSTANG) database to determine rates of discordance and clinical consequences of inaccuracy. MATERIALS AND METHODS: A confusion matrix was constructed for pairs among Rad, Surg, and Path. Accuracy was reported using chronologically latest diagnosis as gold standard. "Concordance" (C) was achieved when both agreed on the severity grade and "Discordance"(D) when they disagreed. A composite endpoint("COMP"= 30-d incidence of surgical site infection, abscess, wound complication, Clavien-Dindo complication, secondary intervention, ED[Emergency Department] visit, hospital readmission, and mortality) was compared between C versus D groups via χ2 test with Bonferroni correction to define statistical significance(P = 0.05/9 = 0.005). RESULTS: For each pair and diagnosis, subjects were categorized as C or D and compared for the incidence of COMP. Incidence of COMP for Surg and/or Path in C versus D: 16% versus. 26% (p = 0.006, NS by Bonferroni) for acute (A), 39% versus 33% (p = 0.39) for gangrenous (G), and 48% versus 37% (p = 0.035, NS by Bonferroni) for perforated (P). For Rad and/or Path in C versus. D: 17% versus 42% (p < 0.001) for A, 27% versus 31% (p = 0.95) for G, and 56% versus 48% (p = 0.48) for P. For C versus D: 17% versus 40% (p < 0.001) for A, 36% versus 26% (p = 0.43) for G, and 51% versus 39% (p = 0.29) for P. CONCLUSIONS: In appendicitis treated by appendectomy, surgeons are most accurate at diagnosing acute appendicitis and least accurate at diagnosing gangrenous. Radiologists are less accurate for all categories. When the surgeon is wrong, clinical outcomes are not significantly worse. However, when the radiologist is wrong about acute appendicitis, patients have worse clinical outcomes.

Validating the ATLS Shock Classification for Predicting Death, Transfusion, or Urgent Intervention.

BACKGROUND: The Advanced Trauma Life Support (ATLS) shock classification has been accepted as the conceptual framework for clinicians caring for trauma patients. We sought to validate its ability to predict mortality, blood transfusion, and urgent intervention. MATERIALS AND METHODS: We performed a retrospective review of trauma patients using the 2014 National Trauma Data Bank. Using initial vital signs data, patients were categorized into shock class based on the ATLS program. Rates for urgent blood transfusion, urgent operative intervention, and mortality were compared between classes. RESULTS: 630,635 subjects were included for analysis. Classes 1, 2, 3, and 4 included 312,404, 17,133, 31, and 43 patients, respectively. 300,754 patients did not meet criteria for any ATLS shock class. Of the patients in class 1 shock, 2653 died (0.9%), 3123 (1.0%) were transfused blood products, and 7115 (2.3%) underwent an urgent procedure. In class 2, 219 (1.3%) died, 387 (2.3%) were transfused, and 1575 (9.2%) underwent intervention. In class 3, 7 (22.6%) died, 10 (32.3%) were transfused, and 13 (41.9%) underwent intervention. In class 4, 15 (34.9%) died, 19 (44.2%) were transfused, and 23 (53.5%) underwent intervention. For uncategorized patients, 21,356 (7.1%) died, 15,168 (5.0%) were transfused, and 23,844 (7.9%) underwent intervention. CONCLUSIONS: Almost half of trauma patients do not meet criteria for any ATLS shock class. Uncategorized patients had a higher mortality (7.1%) than patients in classes 1 and 2 (0.9% and 1.3%, respectively). Classes 3 and 4 only accounted for 0.005% and 0.007%, respectively, of patients. The ATLS classification system does not help identify many patients in severe shock.

Narrow- versus Broad-Spectrum Antibiotics for Simple Acute Appendicitis Treated by Appendectomy: A Post Hoc Analysis of EAST MUSTANG Study.

BACKGROUND: We sought to compare the effectiveness of narrow- versus broad-spectrum antibiotics (abx) in preventing infectious complications in adults with acute appendicitis treated with appendectomy. METHODS: In this post hoc analysis of a prospective multicenter observational study of appendicitis in adults (≥18 y) conducted from January 2017 to June 2018, we included only patients with simple appendicitis. Subjects were grouped based on receipt of broad-spectrum or narrow-spectrum abx before and/or after appendectomy. Outcomes compared were surgical site infection, intra-abdominal abscess, secondary interventions (percutaneous drainage or operation), emergency department (ED) visits, 30-d readmission, and hospital length of stay. RESULTS: A total of 2336 subjects were analyzed. In comparing narrow (n = 778) versus broad (n = 1558) groups, there were no differences in male sex (53% versus 54%, P = 0.704), white blood cell (13.0 ± 3.9 versus 13.4 ± 4.5, P = 0.05), Alvarado score (6 [5-7] versus 6 [5-7], P = 0.25), or Charlson comorbidity index (0 [0-1] versus 0 [0-1], P = 0.09). A total of 688 (29%) received postoperative abx, [184 (24%) narrow and 504 (32%) broad, P < 0.001] for a median 5 [2-7] d [42 (23%) narrow and 235 (47%) broad, P < 0.001]. There were no significant differences between narrow and broad groups in surgical site infection, intra-abdominal abscess, secondary interventions, ED visits, or hospital readmissions. CONCLUSIONS: Significant practice variation in duration and spectrum of antibiotic adjunct for surgical treatment of simple acute appendicitis treatment is evident, and broad-spectrum abx did not offer clinical advantages over narrow-spectrum abx. Restriction of antibiotic spectrum should be considered, although randomized trials are required to overcome selection bias.

Complicated Appendicitis: Are Extended Antibiotics Necessary? A Post Hoc Analysis of the EAST Appendicitis "MUSTANG" Study.

BACKGROUND: The need for extended postoperative antibiotics (Abx) for complicated (gangrenous or perforated) appendicitis (CA) remains unclear. We hypothesize that giving ≤24 h of Abx for CA is not inferior to a longer duration in preventing infectious complications after appendectomy. METHODS: In this post hoc analysis of a prospective multicenter study, only patients with intraoperative diagnosis of CA were included. ANOVA and Chi-squared tests were used to compare length of stay, 30-day readmission rates, surgical site infection (SSI), and intra-abdominal abscess (IAA) between patients receiving ≥96 h and ≤24 h of Abx. RESULTS: Of 751 patients with CA, 704 met inclusion criteria. Mean age was 48 (±17) y; 391 (56%) were male. A total of 185 (26%) received Abx for ≤24 h and 100 (14% of overall) received no Abx. 85 (12%) patients were lost to follow-up at 30 d postop. Twenty-seven (4%) patients developed an SSI (≤24 h = 5 (3%), ≥96 h = 22 (5%), P = 0.502) and 82 (13%) developed IAA (≤24 h = 11 (7%), ≥96 h = 71 (15%), P = 0.008) within 30d postop. Sixty-six (11%) patients underwent a secondary intervention for infection within 30 d postop. 41% of SSIs (11/27) and 60% (49/82) of IAA occurred during the index hospitalization. On the multivariate analysis, there was not any evidence of an association between the duration of Abx and an increased rate of SSI (P = 0.539), IAA (P = 0.274), emergency department visits (P = 0.509), readmission (P = 0.911), or secondary interventions (P = 0.523). CONCLUSIONS: No evidence of an association between the duration of Abx (≤24 h versus ≥ 96 h) for complicated appendicitis and an increased rate of SSI was observed and ≤24 h duration was associated with shorter length of stay. Because of possible selection bias, adequately powered randomized trials are required to definitely prove noninferiority of shorter course Abx duration.

Assortative Mating by an Obliquely Transmitted Local Cultural Trait Promotes Genetic Divergence: A Model.

The effect of learned culture (e.g., birdsong dialects and human languages) on genetic divergence is unclear. Previous theoretical research suggests that because oblique learning allows phenotype transmission from individuals with no offspring to an unrelated individual in the next generation, the effect of sexual selection on the learned trait is masked. However, I propose that migration and spatially constrained learning can form statistical associations between cultural and genetic traits, which may allow selection on the cultural traits to indirectly affect the genetic traits. Here, I build a population genetic model that allows such statistical associations to form and find that sexual selection and divergent selection on the cultural trait can indeed help maintain genetic divergence through such statistical associations, while selection against genetic hybrids does not affect cultural trait divergence. Furthermore, I find that even when the cultural trait changes over time due to drift and mutation, it can still help maintain genetic divergence. These results suggest the role of obliquely transmitted traits in evolution may be underrated, and the lack of one-to-one associations between cultural and genetic traits may not be sufficient to disprove the role of culture in genetic divergence.

Cultural linkage: the influence of package transmission on cultural dynamics.

Many cultural traits are not transmitted independently, but together as a package. This can happen because, for example, media may store information together making it more likely to be transmitted together, or through cognitive mechanisms such as causal reasoning. Evolutionary biology suggests that physical linkage of genes (being on the same chromosome) allows neutral and maladaptive genes to spread by hitchhiking on adaptive genes, while the pairwise difference between neutral genes is unaffected. Whether packaging may lead to similar dynamics in cultural evolution is unclear. To understand the effect of cultural packages on cultural evolutionary dynamics, we built an agent-based simulation that allows links to form and break between cultural traits. During transmission, one trait and others that are directly or indirectly connected to it are transmitted together in a package. We compare variation in cultural traits between different rates of link formation and breakage and find that an intermediate frequency of links can lower cultural diversity, which can be misinterpreted as a signature of payoff bias or conformity. Further, cultural hitchhiking can occur when links are common.

Blunt Trauma: What Is Behind the Widened Mediastinum on Chest X-Ray (CXR)?

BACKGROUND: It is commonly taught that a widened mediastinum (WM) on chest X-ray (CXR) is a marker for aortic injury (AI). We sought to describe the epidemiology of injuries for all patients with WM and compare their CXR to those of patients with confirmed AI. METHODS: Adults (age ≥ 18) sustaining blunt traumatic injuries from January 2017 to June 2017 with both CXR (supine, anterior-posterior) and chest CT were included. We excluded those whose CT preceded CXR and those with missing data. Basic demographics, injury characteristics, mediastinal width (MW), mediastinal-to-thoracic width ratio (MTR), and all thoracic imaging findings were analyzed. MW > 8 cm was considered WM. We also queried our registry for all AI patients over a 4-year period. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of WM on CXR for AI were calculated. Multivariate logistic regression was performed to identify factors associated with positive traumatic findings, controlling for body mass index (BMI), sex, high-energy mechanism, MTR, and mediastinal width. RESULTS: Of 749 included subjects, 502 (67%) had an MW > 8 cm: mean age was 48 ± 20 y, 381 (76%) were men, and BMI was 28 ± 5 kg/m2. Mechanism of injury was motor vehicle crash in 335 (67%); fall in 113 (23%); assault in 31 (6%); other (jet-ski accidents, etc.) in 17 (3%), and unknown in 6 (1%). Only 128 (26%) of patients with WM had positive findings on CT, with the most common [80 (16%)] being nontraumatic findings (pericardial infusion, lymph nodes, etc.), followed by hemomediastinum/pneumomediastinum [32 (6%)], sternal fractures [18 (4%)], multiple findings [15 (3%)], and vertebral fractures [6 (1%)]. Only 2 (1%) had AI. The sensitivity was 100%, specificity was 33%, PPV was 0.4%, NPV was 100%, and accuracy was 33%. From 2013 to 2017, 38 patients had AI: mean age was 46 ± 19 y, 26 (68%) were men, and BMI was 28 ± 4 kg/m2. Motor vehicle crash was the most common mechanism (89%), followed by "other" trauma mechanism (5%), fall (3%), and assault (3%). On univariate analysis, compared with all patients with WM, patients with AI had significantly greater MW (9.5 [8.8-10.4] versus 10.2 [9.1-11.1]; P = 0.042) and MTR (0.31 [0.28-0.34] versus 0.32 [0.31-0.37]; P = 0.001), although the actual differences were not clinically significant. The regression analysis did not identify any factors associated with traumatic CXR findings. CONCLUSIONS: Most bluntly injured adults have a WM, and the majority have either no findings or nontraumatic findings. The PPV of a WM for AI is <1%. WM on supine CXR is nonspecific and inaccurate for diagnosing traumatic injuries, especially AI.

Spontaneous Retroperitoneal and Rectus Sheath Hemorrhage-Management, Risk Factors and Outcomes.

BACKGROUND: Spontaneous retroperitoneal and rectus sheath hemorrhage (SRRSH) is associated with high mortality in the literature, but studies on the subject are lacking. The objective of this study was to identify early predictors of the need for angiographic or surgical intervention (ASI) in patients with SRRSH and define risk factors for mortality. METHODS: We conducted a retrospective cohort study at a tertiary academic hospital. All patients with computed tomography-identified SRRSH between 2012 to 2017 were included. Exclusion criteria were age below 18 years, possible mechanical cause of SRRSH, aortic aneurysm rupture or dissection, and traumatic or iatrogenic sources of SRRSH. The primary outcome was the incidence of ASI and/or mortality. RESULTS: Of 100 patients included (median age 70 years, 52% males), 33% were transferred from another hospital, 82% patients were on therapeutic anticoagulation, and 90% had serious comorbidities. Overall mortality was 22%, but SRRSH-related mortality was only 6%. Sixteen patients underwent angiographic intervention (n = 10), surgical intervention (n = 5), or both (n = 1). Flank pain (OR 4.15, 95% CI 1.21-14.16, p = 0.023) and intravenous contrast extravasation (OR 3.89, 95% CI 1.23-12.27, p = 0.020) were independent predictors of ASI. Transfer from another hospital (OR 3.72, 95% CI 1.30-10.70, p = 0.015), age above 70 years (OR 4.24, 95% CI 1.25-14.32, p = 0.020), and systolic blood pressure below 110 mmHg at the time of diagnosis (OR 4.59, 95% CI 1.19-17.68, p = 0.027) were independent predictors of mortality. CONCLUSIONS: SRRSH is associated with high mortality but is typically not the direct cause. Most SRRSHs are self-limited and require no intervention. Pattern identification of ASI is hard.

Derivation and validation of a practical Bedside Score for the diagnosis of cholecystitis.

OBJECTIVE: We sought to develop a practical Bedside Score for the diagnosis of cholecystitis and test its accuracy against the Tokyo Guidelines (TG13). METHODS: We conducted a retrospective study of 438 patients undergoing urban, academic Emergency Department (ED) evaluation of RUQ pain. Symptoms, physical signs, ultrasound signs, and labs were scoring system candidates. A random split-sample approach was used to develop and validate a new clinical score. Multivariable regression analysis using development data was conducted to identify predictors of cholecystitis. Cutoff values were chosen to ensure positive/negative predictive values (PPV, NPV) of at least 0.95. The score was externally validated in 80 patients at a different hospital undergoing RUQ pain evaluation. RESULTS: 230 patients (53%) had cholecystitis. Five variables predicted cholecystitis and were included in the scores: gallstones, gallbladder thickening, clinical or ultrasonographic Murphy's sign, RUQ tenderness, and post-prandial symptoms. A clinical prediction score was developed. When dichotomized at 4, overall accuracy for acute cholecystitis was 90% for the development cohort, 82% and 86% for the internal and external validation cohorts; TG13 accuracy was 62%-79%. CONCLUSIONS: A clinical prediction score for cholecystitis demonstrates accuracy equivalent to TG13. Use of this score may streamline work-up by decreasing the need for comprehensive ultrasound evaluation and CRP measurement and may shorten ED length of stay.

The malnutrition in polytrauma patients (MaPP) study: Research protocol.

BACKGROUND: Polytrauma patients are at risk of considerable harm from malnutrition due to the metabolic response to trauma. However, there is little knowledge of (the risk of) malnutrition and its consequences in these patients. Recognition of sub-optimally nourished polytrauma patients and their nutritional needs is crucial to prevent complications and optimize their clinical outcomes. AIM: The primary objective is to investigate whether polytrauma patients admitted to the Intensive Care Unit (ICU) who have or develop malnutrition have a higher complication rate than patients who are and remain well nourished. Secondary objectives are to determine the prevalence of pre-existent and in-hospital acquired malnutrition in these patients, to assess the association between malnutrition and long-term outcomes, and to determine the association between serum biomarkers (albumin and pre-albumin) and malnutrition. METHODS: This international observational prospective cohort study will be performed at three Level-1 trauma centers in the United States and two Level-1 centers in the Netherlands. Adult polytrauma patients (Injury Severity Score ≥16) admitted to the ICU of one of the participating centers directly from the Emergency Department are eligible for inclusion. Nutritional status and risk of malnutrition will be assessed using the Subjective Global Assessment (SGA) scale and Nutritional Risk in Critically Ill (NUTRIC) score, respectively. Nutritional intake, biomarkers and complications will be collected daily. Patients will be followed up to one year after discharge for long-term outcomes. CONCLUSIONS: This international prospective cohort study aims to gain more insight into the effect and consequences of malnutrition in polytrauma patients admitted to the ICU.

Hidden Costs of Hospitalization After Firearm Injury: National Analysis of Different Hospital Readmission.

OBJECTIVE: To compare the risk factors and costs associated with readmission after firearm injury nationally, including different hospitals. BACKGROUND: No national studies capture readmission to different hospitals after firearm injury. METHODS: The 2013 to 2014 Nationwide Readmissions Database was queried for patients admitted after firearm injury. Logistic regression identified risk factors for 30-day same and different hospital readmission. Cost was calculated. Survey weights were used for national estimates. RESULTS: There were 45,462 patients admitted for firearm injury during the study period. The readmission rate was 7.6%, and among those, 16.8% were readmitted to a different hospital. Admission cost was $1.45 billion and 1-year readmission cost was $131 million. Sixty-four per cent of those injured by firearms were publicly insured or uninsured. Readmission predictors included: length of stay >7 days [odds ratio (OR) 1.43, P < 0.01], Injury Severity Score >15 (OR 1.41, P < 0.01), and requiring an operation (OR 1.40, P < 0.01). Private insurance was a predictor against readmission (OR 0.81, P < 0.01). Predictors of readmission to a different hospital were unique and included: initial admission to a for-profit hospital (OR 1.52, P < 0.01) and median household income ≥$64,000 (OR 1.48, P < 0.01). CONCLUSIONS: A significant proportion of the national burden of firearm readmissions is missed by not tracking different hospital readmission and its unique set of risk factors. Firearm injury-related hospitalization costs $791 million yearly, with the largest fraction paid by the public. This has implications for policy, benchmarking, quality, and resource allocation.

Prospective evaluation of a continuous infusion vancomycin dosing nomogram in critically ill patients undergoing continuous venovenous haemofiltration.

OBJECTIVES: The most optimal method of attaining therapeutic vancomycin concentrations during continuous venovenous haemofiltration (CVVH) remains unclear. Studies have shown continuous infusion vancomycin (CIV) achieves target concentrations more rapidly and consistently when compared with intermittent infusion. Positive correlations between CVVH intensity and vancomycin clearance (CLvanc) have been noted. This study is the first to evaluate a CIV regimen in patients undergoing CVVH that incorporates weight-based CVVH intensity (mL/kg/h) into the dosing nomogram. METHODS: This was a prospective, observational study of patients undergoing CVVH and receiving CIV based on the nomogram. The primary outcome was achievement of a therapeutic vancomycin concentration (15-25 mg/L) at 24 h. Secondary outcomes included the achievement of therapeutic concentrations at 48 and 72 h. RESULTS: The nomogram was analysed in 52 critically ill adults. Vancomycin concentrations were therapeutic in 43/52 patients (82.7%) at 24 h. Of the nine patients who were not therapeutic at 24 h, seven were supratherapeutic and two were subtherapeutic. The mean (SD) concentration was 20.1 (4.2) mg/L at 24 h, 20.7 (3.7) mg/L at 48 h and 21.9 (3.5) mg/L at 72 h. Patients with CVVH intensity >20 mL/kg/h experienced higher CLvanc at 24 h compared with patients with CVVH intensity <20 mL/kg/h (3.1 versus 2.6 L/h; P = 0.013). CONCLUSIONS: By incorporating CVVH intensity into the CIV dosing nomogram, the majority of patients achieved therapeutic concentrations at 24 h and maintained them within range at 48 and 72 h. Additional studies are required to validate this nomogram before widespread implementation may be considered.

Elevated Red Cell Distribution Width Is Associated With Decreased Ventilator-Free Days in Critically Ill Patients.

INTRODUCTION: Elevated red cell distribution width (RDW) is associated with mortality in a variety of respiratory conditions. Recent data also suggest that RDW is associated with mortality in intensive care unit (ICU) patients. Although respiratory failure is common in the ICU, the relationship between RDW and pulmonary outcomes in the ICU has not been previously explored. Therefore, our goal was to investigate the association of admission RDW with 30-day ventilator-free days (VFDs) in ICU patients. METHODS: We performed a retrospective analysis from an ongoing prospective, observational study. Patients were recruited from medical and surgical ICUs of a large teaching hospital in Boston, Massachusetts. The RDW was assessed within 1 hour of ICU admission. Poisson regression analysis was used to investigate the association of RDW (normal: 11.5%-14.5% vs elevated: >14.5%) with 30-day VFD, while controlling for age, sex, race, body mass index, Nutrition Risk in the Critically Ill score, the presence of chronic lung disease, Pao2/Fio2 ratio, and admission levels of hemoglobin, mean corpuscular volume, phosphate, albumin, C-reactive protein, and creatinine. RESULTS: A total of 637 patients comprised the analytic cohort. Mean RDW was 15 (standard deviation 4%), with 53% of patients in the normal range and 47% with elevated levels. Median VFD was 16 (interquartile range: 6-25) days. Poisson regression analysis demonstrated that ICU patients with elevated admission RDW were likely to have 32% lower 30-day VFDs compared to their counterparts with RDW in the normal range (incidence rate ratio: 0.68; 95% confidence interval: 0.55-0.83: P < .001). CONCLUSIONS: We observed an inverse association of RDW and 30-day VFD, despite controlling for demographics, nutritional factors, and severity of illness. This supports the need for future studies to validate our findings, understand the physiologic processes that lead to elevated RDW in patients with respiratory failure, and determine whether changes in RDW may be used to support clinical decision-making.

Gallstone Pancreatitis and Choledocholithiasis: Using Imaging and Laboratory Trends to Predict the Likelihood of Persistent Stones at Cholangiography.

BACKGROUND: Patients with gallstone pancreatitis (GP) or choledocholithiasis (CDL) may have common bile duct (CBD) stones that persist until cholangiography. The aim of this study is to evaluate pre-cholangiogram factors that predict persistent CBD stones. METHODS: Multiple logistic regression analyses were performed to identify demographic, laboratory, and radiologic predictors of persistent CBD stones and non-therapeutic cholangiography among adults with GP or CDL. RESULTS: In 152 patients from 2010 to 2015, preoperative diagnosis, presence of a CBD stone on US, and age ≥ 60 years were associated with persistent CBD stones. Two risk factors alone had a PPV of 88% and the absence of all risk factors had a NPV of 94%. Age < 60 years and the absence of a CBD stone on US were most predictive of non-therapeutic cholangiography. CONCLUSION: Age, LFTs, and US help predict persistent CBD stones in patients initially presenting with GP or CDL and help minimize non-therapeutic preoperative cholangiography.

Intraoperative Adverse Events in Abdominal Surgery: What Happens in the Operating Room Does Not Stay in the Operating Room.

OBJECTIVE: We sought to assess the impact of intraoperative adverse events (iAEs) on 30-day postoperative mortality, 30-day postoperative morbidity, and postoperative length of stay (LOS) among patients undergoing abdominal surgery. We hypothesized that iAEs would be associated with significant increases in each outcome. SUMMARY OF BACKGROUND DATA: The relationship between iAEs and postoperative clinical outcomes remains largely unknown. METHODS: The 2007 to 2012 institutional ACS-NSQIP and administrative databases for abdominal surgeries were matched then screened for iAEs using the Agency for Healthcare Research and Quality's 15 Patient Safety Indicator, "Accidental Puncture/Laceration". Each chart flagged during the initial screen was then manually reviewed to confirm whether an iAE occurred. Univariate then multivariable logistic regression models were constructed to assess the independent impact of iAEs on 30-day mortality, 30-day morbidity, and prolonged (≥7 days) postoperative LOS, controlling for preoperative/intraoperative variables (eg, age, comorbidities, ASA, wound classification), procedure type (eg, laparoscopic vs open, intestinal, foregut, hepatopancreaticobiliary vs abdominal wall procedure), and complexity (eg, adhesions; relative value units). Propensity score analyses were conducted with each iAE patient matched with 5 non-iAE patients. Sensitivity analyses were performed. RESULTS: A total of 9288 cases were included; 183 had iAEs. Most iAEs consisted of bowel (44%) or vessel (29%) injuries and were addressed intraoperatively (92%). In multivariable analyses, iAEs were independently associated with increased 30-day mortality [OR = 3.19, 95% confidence interval (CI) 1.52-6.71, P = 0.002], 30-day morbidity (OR = 2.68, 95% CI 1.89-3.81, P < 0.001), and prolonged postoperative LOS (OR = 1.85, 95% CI 1.27-2.70, P = 0.001). Postoperative complications associated with iAEs included deep/organ-space surgical site infection (OR = 1.94, 95% CI 1.20-3.14), P = 0.007), sepsis (OR = 2.14, 95% CI 1.32-3.47, P = 0.002), pneumonia (OR = 2.18, 95% CI 1.11-4.26, P = 0.023), and failure to wean ventilator (OR = 3.88, 95% CI 2.17-6.95, P < 0.001). Propensity score matching confirmed these findings, as did multiple sensitivity analyses. CONCLUSIONS: iAEs are independently associated with substantial increases in postoperative mortality, morbidity, and prolonged LOS. Quality improvement efforts should focus on iAE prevention, mitigation of harm after iAEs occur, and risk/severity-adjusted iAE tracking and benchmarking.

Not just a theory--the utility of mathematical models in evolutionary biology.

Progress in science often begins with verbal hypotheses meant to explain why certain biological phenomena exist. An important purpose of mathematical models in evolutionary research, as in many other fields, is to act as "proof-of-concept" tests of the logic in verbal explanations, paralleling the way in which empirical data are used to test hypotheses. Because not all subfields of biology use mathematics for this purpose, misunderstandings of the function of proof-of-concept modeling are common. In the hope of facilitating communication, we discuss the role of proof-of-concept modeling in evolutionary biology.