A Pilot Machine Learning Study Using Trauma Admission Data to Identify Risk for High Length of Stay.

INTRODUCTION: Trauma patients have diverse resource needs due to variable mechanisms and injury patterns. The aim of this study was to build a tool that uses only data available at time of admission to predict prolonged hospital length of stay (LOS). METHODS: Data was collected from the trauma registry at an urban level one adult trauma center and included patients from 1/1/2014 to 3/31/2019. Trauma patients with one or fewer days LOS were excluded. Single layer and deep artificial neural networks were trained to identify patients in the top quartile of LOS and optimized on area under the receiver operator characteristic curve (AUROC). The predictive performance of the model was assessed on a separate test set using binary classification measures of accuracy, precision, and error. RESULTS: 2953 admitted trauma patients with more than one-day LOS were included in this study. They were 70% male, 60% white, and averaged 47 years-old (SD: 21). 28% were penetrating trauma. Median length of stay was 5 days (IQR 3-9). For prediction of prolonged LOS, the deep neural network achieved an AUROC of 0.80 (95% CI: 0.786-0.814) specificity was 0.95, sensitivity was 0.32, with an overall accuracy of 0.79. CONCLUSION: Machine learning can predict, with excellent specificity, trauma patients who will have prolonged length of stay with only physiologic and demographic data available at the time of admission. These patients may benefit from additional resources with respect to disposition planning at the time of admission.

The Utility of Carbohydrate-Deficient Transferrin in Identifying Chronic Alcohol Users in the Injured Patient: Expanding the Toolkit.

BACKGROUND: Alcohol use remains abundant in patients with traumatic injury. Previous studies have suggested that serum carbohydrate-deficient transferrin (%dCDT) levels, relative to blood alcohol levels (BALs), may better differentiate episodic binge drinkers from sustained heavy consumers in admitted patients with traumatic injury. We characterized %dCDT levels and BAL levels to differentiate binge drinkers from sustained heavy consumers in admitted trauma patients and their associations with outcomes. METHODS: This prospective, cross-sectional, observational study assessed %dCDT and BAL levels in admitted male and female patients with traumatic injury (≥18 y) at an American College of Surgeons Committee on Trauma level-1 center from July 2014 to June 2016. We designated patients with %dCDT levels ≥1.7% (CDT+) as chronic alcohol users and dichotomized acutely intoxicated patients using three different BAL-level thresholds. Primary outcomes included in-hospital complications, along with prolonged ventilation and intensive care unit length of stay, both defined as the top decile. Secondary outcomes included rates of drug or alcohol withdrawal and all-cause mortality. Analyses were adjusted for clinical factors. RESULTS: We studied 715 patients (77.5% men, 60.6% ≤ 40 y of age, median Injury Severity Score: 14, 41.7% motor vehicle crashes, 17.9% gunshot wounds, 11.1% falls). While 31.0% were CDT+, 48.7% were BAL>0. After adjusting for CDT levels, BAL levels >0, >100, or >200 were not associated with adverse outcomes. However, CDT+ relative to patients with CDT were associated with complications (adjusted odds ratio: 1.96 [1.24-3.09]), prolonged ventilation days (3.23 [1.08-9.65]), and prolonged intensive care unit stays (2.83 [1.20-6.68]). CONCLUSIONS: In this 2-year prospective, cross-sectional, and observational study, we found that %dCDT levels, relative to BAL levels, may better stratify admitted patients with traumatic injury into acute versus chronic alcohol users, identifying those at higher risk for in-hospital complications.

Delay in emergency hernia surgery is associated with worse outcomes.

BACKGROUND: Patients requiring emergent surgery for hernia vary widely in presentation and management. The purpose of this study was to determine if the variation in timing of urgent surgery impacts surgical outcomes. METHODS: The national NSQIP database for years 2011-2016 was queried for emergent surgeries for abdominal hernia resulting in obstruction or gangrene by primary post-op diagnosis. Diaphragmatic hernias were excluded. Patients were grouped by surgical timing from admission to day of surgery: same day, next day, and longer delay. Multinomial propensity score weighting was used to address potential differences in underlying covariates' clustering across the timing groups followed by multivariable logistic regression of morbidity and mortality. RESULTS: Weighted analysis yielded an effective sample size of 76,364. Hernia types included inguinal (20.9%); femoral (6.7%); umbilical (20.2%); ventral (41.0%); and other (10.4%). Delayed surgery was associated with increased rates of major complications (26.4% vs. 20.9%, p < 0.001), longer operative times (+ 12.5 min, p < 0.001), longer postoperative lengths of stay (+ 1.6 days, p < 0.001), increased re-operations (5.9% vs. 4.7%, p = 0.019), increased readmissions (7.0% vs. 5.7%, p = 0.004), and increased 30-day mortality (2.4% vs. 1.7%, p = 0.002). When controlling for other factors, next-day surgery (OR 1.23, 95% CI 1.05-1.45, p = 0.009) and surgery delayed more than one day (OR 1.40, 95% CI 1.13-1.73, p < 0.002) were associated with an increased odds of a major complication. Mortality and readmission by timing of surgery were not independently significant. CONCLUSIONS: Delay in surgery for emergent hernias increased the odds of major morbidity but not mortality. Patients presenting with hernia and an indication for urgent surgical intervention may benefit from an operation as soon as feasible rather than warrant waiting for further physiologic optimization, medical clearance, or specialized surgical personnel.

Robotic Technology in Emergency General Surgery Cases in the Era of Minimally Invasive Surgery.

Importance: Although robotic surgery has become an established approach for a wide range of elective operations, data on its utility and outcomes are limited in the setting of emergency general surgery. Objectives: To describe temporal trends in the use of laparoscopic and robotic approaches and compare outcomes between robotic and laparoscopic surgery for 4 common emergent surgical procedures. Design, Setting, and Participants: A retrospective cohort study of an all-payer discharge database of 829 US facilities was conducted from calendar years 2013 to 2021. Data analysis was performed from July 2022 to November 2023. A total of 1 067 263 emergent or urgent cholecystectomies (n = 793 800), colectomies (n = 89 098), inguinal hernia repairs (n = 65 039), and ventral hernia repairs (n = 119 326) in patients aged 18 years or older were included. Exposure: Surgical approach (robotic, laparoscopic, or open) to emergent or urgent cholecystectomy, colectomy, inguinal hernia repair, or ventral hernia repair. Main Outcomes and Measures: The primary outcome was the temporal trend in use of each operative approach (laparoscopic, robotic, or open). Secondary outcomes included conversion to open surgery and length of stay (both total and postoperative). Temporal trends were measured using linear regression. Propensity score matching was used to compare secondary outcomes between robotic and laparoscopic surgery groups. Results: During the study period, the use of robotic surgery increased significantly year-over-year for all procedures: 0.7% for cholecystectomy, 0.9% for colectomy, 1.9% for inguinal hernia repair, and 1.1% for ventral hernia repair. There was a corresponding decrease in the open surgical approach for all cases. Compared with laparoscopy, robotic surgery was associated with a significantly lower risk of conversion to open surgery: cholecystectomy, 1.7% vs 3.0% (odds ratio [OR], 0.55 [95% CI, 0.49-0.62]); colectomy, 11.2% vs 25.5% (OR, 0.37 [95% CI, 0.32-0.42]); inguinal hernia repair, 2.4% vs 10.7% (OR, 0.21 [95% CI, 0.16-0.26]); and ventral hernia repair, 3.5% vs 10.9% (OR, 0.30 [95% CI, 0.25-0.36]). Robotic surgery was associated with shorter postoperative lengths of stay for colectomy (-0.48 [95% CI, -0.60 to -0.35] days), inguinal hernia repair (-0.20 [95% CI, -0.30 to -0.10] days), and ventral hernia repair (-0.16 [95% CI, -0.26 to -0.06] days). Conclusions and Relevance: While robotic surgery is still not broadly used for emergency general surgery, the findings of this study suggest it is becoming more prevalent and may be associated with better outcomes as measured by reduced conversion to open surgery and decreased length of stay.

Sonographic evaluation of intravascular volume status in the surgical intensive care unit: a prospective comparison of subclavian vein and inferior vena cava collapsibility index.

BACKGROUND: Traditional methods for intravascular volume status assessment are invasive and are associated significant complications. While focused bedside sonography of the inferior vena cava (IVC) has been shown to be useful in estimating intravascular volume status, it may be technically difficult and limited by patient factors such as obesity, bowel gas, or postoperative surgical dressings. The goal of this investigation is to determine the feasibility of subclavian vein (SCV) collapsibility as an adjunct to IVC collapsibility in intravascular volume status assessment. METHODS: A prospective study was conducted on a convenience sample of surgical intensive care unit patients to evaluate interchangeability of IVC collapsibility index (IVC-CI) and SCV-CI. After demographic and acuity of illness information was collected, all patients underwent serial, paired assessments of IVC-CI and SCV-CI using portable ultrasound device (M-Turbo; Sonosite, Bothell, WA). Vein collapsibility was calculated using the formula [collapsibility (%) = (max diameter - min diameter)/max diameter × 100%]. Paired measurements from each method were compared using correlation coefficient and Bland-Altman measurement bias analysis. RESULTS: Thirty-four patients (mean age 56 y, 38% female) underwent a total of 94 paired SCV-CI and IVC-CI sonographic measurements. Mean acute physiology and chronic health evaluation II score was 12. Paired SCV- and IVC-CI showed acceptable correlation (R(2) = 0.61, P < 0.01) with acceptable overall measurement bias [Bland-Altman mean collapsibility difference (IVC-CI minus SCV-CI) of -3.2%]. In addition, time needed to acquire and measure venous diameters was shorter for the SCV-CI (70 s) when compared to IVC-CI (99 s, P < 0.02). CONCLUSIONS: SCV collapsibility assessment appears to be a reasonable adjunct to IVC-CI in the surgical intensive care unit patient population. The correlation between the two techniques is acceptable and the overall measurement bias is low. In addition, SCV-CI measurements took less time to acquire than IVC-CI measurements, although the clinical relevance of the measured time difference is unclear.

Association of Whole Blood With Survival Among Patients Presenting With Severe Hemorrhage in US and Canadian Adult Civilian Trauma Centers.

Importance: Whole-blood (WB) resuscitation has gained renewed interest among civilian trauma centers. However, there remains insufficient evidence that WB as an adjunct to component therapy-based massive transfusion protocol (WB-MTP) is associated with a survival advantage over MTP alone in adult civilian trauma patients presenting with severe hemorrhage. Objective: To assess whether WB-MTP compared with MTP alone is associated with improved survival at 24 hours and 30 days among adult trauma patients presenting with severe hemorrhage. Design, Setting, and Participants: This retrospective cohort study using the American College of Surgeons Trauma Quality Improvement Program databank from January 1, 2017, and December 31, 2018, included adult trauma patients with a systolic blood pressure less than 90 mm Hg and a shock index greater than 1 who received at least 4 units of red blood cells within the first hour of emergency department (ED) arrival at level I and level II US and Canadian adult civilian trauma centers. Patients with burns, death within 1 hour of ED arrival, and interfacility transfers were excluded. Data were analyzed from February 2022 to September 2022. Exposures: Resuscitation with WB-MTP compared with MTP alone within 24 hours of ED presentation. Main Outcomes and Measures: Primary outcomes were survival at 24 hours and 30 days. Secondary outcomes selected a priori included major complications, hospital length of stay, and intensive care unit length of stay. Results: A total of 2785 patients met inclusion criteria: 432 (15.5%) in the WB-MTP group (335 male [78%]; median age, 38 years [IQR, 27-57 years]) and 2353 (84.5%) in the MTP-only group (1822 male [77%]; median age, 38 years [IQR, 27-56 years]). Both groups included severely injured patients (median injury severity score, 28 [IQR, 17-34]; median difference, 1.29 [95% CI, -0.05 to 2.64]). A survival curve demonstrated separation within 5 hours of ED presentation. WB-MTP was associated with improved survival at 24 hours, demonstrating a 37% lower risk of mortality (hazard ratio, 0.63; 95% CI, 0.41-0.96; P = .03). Similarly, the survival benefit associated with WB-MTP remained consistent at 30 days (HR, 0.53; 95% CI, 0.31-0.93; P = .02). Conclusions and Relevance: In this cohort study, receipt of WB-MTP was associated with improved survival in trauma patients presenting with severe hemorrhage, with a survival benefit found early after transfusion. The findings from this study are clinically important as this is an essential first step in prioritizing the selection of WB-MTP for trauma patients presenting with severe hemorrhage.

The evolution and development of a robotic acute care surgery program.

BACKGROUND: Acute care surgeons perform more than 850,000 operations annually on emergency general surgery patients in the United States. Emergency general surgery conditions are associated with a disproportionate excess of patient complications and death. Innovative quality improvement strategies have focused on addressing the excess morbidity and mortality among this patient population. Minimally invasive surgical techniques have been shown to reduce the burden experienced by emergency general surgery patients. Still, limited adoption by acute care surgeons has restricted this application's potential. An institutional robotics acute care surgery program provides acute care surgeons additional opportunities to expand minimally invasive surgery access to emergency general surgery patients irrespective of the time or day of the week. METHODS: A robotics acute care surgery program was developed and implemented at a high-volume academic institution within the division of trauma and acute care surgery. RESULTS: Three attending surgeons and two fellows within the trauma and acute care surgery division had successfully completed a defined robotics clinical pathway. As a result, around-the-clock use of a robotic surgical platform for emergency general surgery cases was implemented with routine use by trained robotic acute care surgeons and practicing fellows. CONCLUSION: The advancement of robotic surgical technology has opened new avenues for surgical application in the emergency setting. The development of a robotic acute care surgery program allows acute care surgeons to diversify their practice while providing greater access to minimally invasive approaches for emergency general surgery patients.

Emergency department versus operating room intubation of patients undergoing immediate hemorrhage control surgery.

BACKGROUND: Hemorrhage control surgery is an essential trauma center function. Airway management of the unstable bleeding patient in the emergency department (ED) presents a challenge. Premature intubation in the ED can exacerbate shock and precipitate extremis. We hypothesized that ED versus operating room intubation of patients requiring urgent hemorrhage control surgery is associated with adverse outcomes at the patient and hospital-levels. METHODS: Patients who underwent hemorrhage control within 60 minutes of arrival at level 1 or 2 trauma centers were identified (National Trauma Data Bank 2017-2019). To minimize confounding, patients dead on arrival, undergoing ED thoracotomy, or with clinical indications for intubation (severe head/neck/face injury or Glasgow Coma Scale score of ≤8) were excluded. Two analytic approaches were used. First, hierarchical logistic regression measured the risk-adjusted association between ED intubation and mortality. Secondary outcomes included ED dwell time, units of blood transfused, and major complications (cardiac arrest, acute respiratory distress syndrome, acute kidney injury, sepsis). Second, a hospital-level analysis determined whether hospital tendency ED intubation was associated with adverse outcomes. RESULTS: We identified 9,667 patients who underwent hemorrhage control surgery at 253 trauma centers. Patients were predominantly young men (median age, 33 years) who suffered penetrating injuries (71%). The median initial Glasgow Coma Scale and systolic blood pressure were 15 and 108 mm Hg, respectively. One in five (20%) of patients underwent ED intubation. After risk-adjustment, ED intubation was associated with significantly increased odds of mortality, longer ED dwell time, greater blood transfusion, and major complications. Hospital-level analysis identified significant variation in use of ED intubation between hospitals not explained by patient case mix. After risk adjustment, patients treated at hospitals with high tendency for ED intubation (compared with those with low tendency) were significantly more likely to suffer in-hospital cardiac arrest (6% vs. 4%; adjusted odds ratio, 1.46; 95% confidence interval, 1.04-2.03). CONCLUSION: Emergency department intubation of patients who require urgent hemorrhage control surgery is associated with adverse outcomes. Significant variation in ED intubation exists between trauma centers not explained by patient characteristics. Where feasible, intubation should be deferred in favor of rapid resuscitation and transport to the operating room. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

Association Between Geospatial Access to Trauma Center Care and Motor Vehicle Crash Mortality in the United States.

BACKGROUND: Motor vehicle crashes (MVCs) are a leading cause of preventable trauma death in the United States (US). Access to trauma center care is highly variable nationwide. The objective of this study was to measure the association between geospatial access to trauma center care and MVC mortality. METHODS: This was a population-based study of MVC-related deaths that occurred in 3,141 US counties (2017-2020). ACS and state-verified level I-III trauma centers were mapped. Geospatial network analysis estimated the ground transport time to the nearest trauma center from the population-weighted centroid for each county. In this way, the exposure was the predicted access time to trauma center care for each county population. Hierarchical negative binomial regression measured the risk-adjusted association between predicted access time and MVC mortality, adjusting for population demographics, rurality, access to trauma resources, and state traffic safety laws. RESULTS: We identified 92,398 crash fatalities over the four-year study period. Trauma centers mapped included 217 level I, 343 level II, and 495 level III trauma centers. The median county predicted access time was 47 min (IQR 26-71 min). Median county MVC mortality was 12.5 deaths/100,000 person-years (IQR 7.4-20.3 deaths/100,000 person-years). After risk-adjustment, longer predicted access times were significantly associated with higher rates of MVC mortality (>60 min vs. <15 min; MRR 1.36; 95%CI 1.31-1.40). This relationship was significantly more pronounced in urban/suburban vs. rural/wilderness counties (p for interaction, <0.001). County access to trauma center care explained 16% of observed state-level variation in MVC mortality. CONCLUSIONS: Geospatial access to trauma center care is significantly associated with MVC mortality and contributes meaningfully to between-state differences in road traffic deaths. Efforts to improve trauma system organization should prioritize access to trauma center care to minimize crash fatalities. LEVEL OF EVIDENCE: Level III, Epidemiological.

Failure to Rescue in Geriatric Trauma: The Impact of Any Complication Increases with Age and Injury Severity in Elderly Trauma Patients.

INTRODUCTION: The interaction of increasing age, Injury Severity Score (ISS), and complications is not well described in geriatric trauma patients. We hypothesized that failure to rescue rate from any complication worsens with age and injury severity. METHODS: The National Trauma Data Bank (NTDB) was queried for injured patients aged 65 years or older from January 1, 2013 through December 31, 2016. Demographics and injury characteristics were used to compare groups. Mortality rates were calculated across subgroups of age and ISS, and captured with heatmaps. Multivariable logistic regression was performed to identify independent predictors of mortality. RESULTS: 614,496 geriatric trauma patients were included; 151,880 (24.7%) experienced a complication. Those with complications tended to be older, female, non-white, have non-blunt mechanism, higher ISS, and hypotension on arrival. Overall mortality was highest (19%) in the oldest (≥86 years old) and most severely injured (ISS ≥ 25) patients, with constant age increasing across each ISS group was associated with a 157% increase in overall mortality (P < .001, 95% CI: 148-167%). Holding ISS stable, increasing age group was associated with a 48% increase in overall mortality (P < .001, 95% CI: 44-52%). After controlling for standard demographic variables at presentation, the existence of any complication was an independent predictor of overall mortality in geriatric patients (OR: 2.3; 95% CI: 2.2-2.4). CONCLUSIONS: Any complication was an independent risk factor for mortality, and scaled with increasing age and ISS in geriatric patients. Differences in failure to rescue between populations may reflect critical differences in physiologic vulnerability that could represent targets for interventions.

Complicating factors in the management of advanced Bouveret syndrome in frail and medically complex patients: Case report and discussion of pathophysiology.

INTRODUCTION: Bouveret Syndrome is a rare but important variant of gallstone ileus with high potential for morbidity and mortality. Bouveret syndrome is a complication of gallstone disease resulting from chronic inflammation and subsequent fistulization between the gallbladder and duodenum or stomach with subsequent impaction of the stone in the proximal GI tract. Here we present a case in an elderly man with moderate medical comorbidities. PRESENTATION OF CASE: An elderly man presented to the hospital with symptoms of gastrointestinal obstruction. Upon further diagnostic work-up, he was noted to have a 5.8 cm gallstone impacted in his proximal GI tract and thus diagnosed with a rare variant of gallstone ileus-Bouveret syndrome. DISCUSSION: The therapeutic goal in approaching Bouveret syndrome is removal of the stone and improvement in obstruction and cholangitis. This may be accomplished with surgery or endoscopic therapy-although this may be less effective. Bouveret syndrome may have high morbidity. CONCLUSION: Bouveret syndrome is a rare but potentially serious syndrome that should be managed accordingly. It should remain on the differential diagnosis of an elderly patient presenting with gastrointestinal obstructions, particularly if there is a history of gallstone disease and concern for proximal GI obstruction.

Functional grading of mineral and collagen in the attachment of tendon to bone.

Attachment of dissimilar materials is a major challenge because high levels of localized stress may develop at their interfaces. An effective biologic solution to this problem exists at one of nature's most extreme interfaces: the attachment of tendon (a compliant, structural "soft tissue") to bone (a stiff, structural "hard tissue"). The goal of our study was to develop biomechanical models to describe how the tendon-to-bone insertion derives its mechanical properties. We examined the tendon-to-bone insertion and found two factors that give the tendon-to-bone transition a unique grading in mechanical properties: 1), a gradation in mineral concentration, measured by Raman spectroscopy; and 2), a gradation in collagen fiber orientation, measured by polarized light microscopy. Our measurements motivate a new physiological picture of the tissue that achieves this transition, the tendon-to-bone insertion, as a continuous, functionally graded material. Our biomechanical model suggests that the experimentally observed increase in mineral accumulation within collagen fibers can provide significant stiffening of the partially mineralized fibers, but only for concentrations of mineral above a "percolation threshold" corresponding to formation of a mechanically continuous mineral network within each collagen fiber (e.g., the case of mineral connectivity extending from one end of the fiber to the other). Increasing dispersion in the orientation distribution of collagen fibers from tendon to bone is a second major determinant of tissue stiffness. The combination of these two factors may explain the nonmonotonic variation of stiffness over the length of the tendon-to-bone insertion reported previously. Our models explain how tendon-to-bone attachment is achieved through a functionally graded material composition, and provide targets for tissue engineered surgical interventions and biomimetic material interfaces.

Unplanned readmission after traumatic injury: A long-term nationwide analysis.

BACKGROUND: Long-term outcomes after trauma admissions remain understudied. We analyzed the characteristics of inpatient readmissions within 6 months of an index hospitalization for traumatic injury. METHODS: Using the 2010 to 2015 Nationwide Readmissions Database, which captures data from up to 27 US states, we identified patients at least 15 years old admitted to a hospital through an emergency department for blunt trauma, penetrating trauma, or burns. Exclusion criteria included hospital transfers, patients who died during their index hospitalizations, and hospitals with fewer than 100 trauma patients annually. After calculating the incidences of all-cause, unplanned inpatient readmissions within 1 month, 3 months, and 6 months, we used multivariable logistic regression models to identify predictors of readmissions. Analyses adjusted for patient, clinical, and hospital factors. RESULTS: Among 2,763,890 trauma patients, the majority had blunt injuries (92.5%), followed by penetrating injuries (6.2%) and burns (1.5%). Overall, rates of inpatient readmissions were 11.1% within 1 month, 21.6% within 6 months, and 29.8% within 6 months, with limited variability by year. After adjustment, the following were associated with all-cause 6 months inpatient readmissions: male sex (adjusted odds ratio [aOR], 1.10; 95% confidence interval [95% CI], 1.09-1.10), comorbidities (aOR, 1.21; 95% CI, 1.21-1.22), low-income quartiles (first and second) (aOR, 1.08; 95% CI, 1.07-1.10 and aOR, 1.04; 95% CI, 1.03-1.06, respectively), Medicare (aOR, 1.65; 95% CI, 1.62-1.69), Medicaid (aOR, 1.51; 95% CI, 1.48-1.53), being treated at private, investor-owned hospitals (aOR, 1.15; 95% CI, 1.12-1.18), longer hospital length of stay (aOR, 1.01; 95% CI, 1.01-1.01) and patient disposition to short-term hospital (aOR, 1.55; 95% CI, 1.49-1.62), skilled nursing facility (aOR, 1.43; 95% CI, 1.42-1.45), home health care (aOR, 1.27; 95% CI, 1.25-1.28), or leaving against medical advice (aOR, 1.85; 95% CI, 1.78-1.92). CONCLUSION: Unplanned readmission after trauma is high and remains this way 6 months after discharge. Understanding the factors that increase the odds of readmissions within 1 month, 3 months, and 6 months offer a focus for quality improvement and have important implications for hospital benchmarking. LEVEL OF EVIDENCE: Epidemiological study, level III.

The tendon-to-bone transition of the rotator cuff: a preliminary Raman spectroscopic study documenting the gradual mineralization across the insertion in rat tissue samples.

We applied Raman spectroscopy to monitor the distribution of mineral and the degree of mineralization across the tendon-bone insertion site in the shoulders of five rats. We acquired Raman spectra from 100 to 4,000 Deltacm(-1) on individual 1 microm points across the 120 microm wide transition zone of each tissue sample and identified all the peaks detected in pure tendon and in pure bone, as well as in the transition zone. The intensity of the 960 Deltacm(-1) P-O stretch for apatite (normalized to either the 2,940 Deltacm(-1) C-H stretch or the 1,003 Deltacm(-1) C-C stretch for collagen) was used as an indicator of the abundance of mineral. We relate the observed histological morphology in the tissue thin section with the observed Raman peaks for both the organic component (mostly collagen) and the inorganic component (a carbonated form of the mineral apatite) and discuss spectroscopic issues related to peak deconvolution and quantification of overlapping Raman peaks. We show that the mineral-to-collagen ratio at the insertion site increases linearly (R(2) = 0.8 for five samples) over the distance of 120 microm from tendon to bone, rather than abruptly, as previously inferred from histological observations. In addition, narrowing of the 960 Deltacm(-1) band across the traverse indicates that the crystalline ordering within the apatite increases concomitantly with the degree of mineralization. This finding of mineral gradation has important clinical implications and may explain why the uninjured tendon-to-bone connection of the rotator cuff can sustain very high loads without failure. Our finding is also consistent with recent mechanical models and calculations developed to better understand the materials properties of this unusually strong interface.

Nationwide trends in mortality following penetrating trauma: Are we up for the challenge?

BACKGROUND: Despite a focus on improved prehospital care, penetrating injuries contribute substantially to trauma mortality in the United States. We therefore analyzed contemporary trends in prehospital mortality from penetrating trauma in the past decade. METHODS: We identified patients in the The National Trauma Data Bank from 2007 to 2010 ("early period") and 2011 to 2014 ("late period") with gunshot wounds (GSW) and stab wounds (SW), who were treated at hospitals that recorded dead-on-arrival statistics. Multivariable logistic regressions assessed differences in body locations of trauma, prehospital mortality, and in-hospital mortality between the early and late periods. Models accounted for hospital clusters and adjusted for age, pulse, hypotension, New Injury Severity Score, Glasgow Coma Scale, and number of injured body parts. RESULTS: From 2007 to 2014, 437,398 patients experienced penetrating traumas, with equal distributions of GSW and SW. There were unadjusted differences in prehospital mortality (GSW: early, 2.0% vs. late, 4.9%; SW: early, 0.2% vs. late, 1.1%) and in-hospital mortality (GSW: early, 13.8% vs. late, 9.5%; SW: early, 1.8% vs. late, 1.0%) by both mechanisms. After adjustment, patients in the late period relative to those in the early period had significantly higher odds of prehospital death (GSWs: adjusted odds ratio [aOR], 4.54; 95% confidence interval [CI], 3.31-6.22; SWs: aOR, 8.98; 95% CI, 5.50-14.67) and lower odds of in-hospital death (GSWs: aOR, 0.85; 95% CI, 0.80-0.90; SWs: aOR, 0.81; 95% CI, 0.71-0.92). Sensitivity analyses assessing GSWs and SWs by locations of body injury found similar results. Additionally, patients in the late period were more likely to experience penetrating injuries to the face, spine, and lower extremities. CONCLUSION: In the United States, the prevalence of penetrating traumas remains a nationwide burden. The odds of prehospital mortality has increased over fourfold for GSWs and almost ninefold for SWs. Examining violence intensity, along with improvements in hospital care and data collection, may explain these findings. LEVEL OF EVIDENCE: Prognostic and epidemiological, level IV.

Facility disparities in reporting comorbidities to the National Trauma Data Bank.

BACKGROUND: The National Trauma Data Bank (NTDB) includes patient comorbidities. This study evaluates factors of trauma centers associated with higher rates of missing comorbidity data. METHODS: Proportions of missing comorbidity data from facilities in the NTDB from 2011 to 2014 were evaluated for associations with facility characteristics. Proportional impact analysis was performed to identify potential policy targets. RESULTS: Of 919 included facilities, 85% reported comorbidity data in 95% or more cases; only 31.3% were missing no data. Missing rates were significantly different based on most facility categories, but independently associated only with hospital size, region, and trauma center level. Only 15% of centers were responsible for over 80% of cases missing data. CONCLUSIONS: There is significant nonrandom variation in reporting trauma patient comorbidities to the NTDB. Missing data needs to be recognized and considered in studies of trauma comorbidities. Targeted intervention may improve data quality.

Dynamic behavior of venous collapsibility and central venous pressure during standardized crystalloid bolus: A prospective, observational, pilot study.

INTRODUCTION: Measurement of intravascular volume status is an ongoing challenge for physicians in the surgical intensive care unit (SICU). Most surrogates for volume status, including central venous pressure (CVP) and pulmonary artery wedge pressure, require invasive lines associated with a number of potential complications. Sonographic assessment of the collapsibility of the inferior vena cava (IVC) has been described as a noninvasive method for determining volume status. The purpose of this study was to analyze the dynamic response in IVC collapsibility index (IVC-CI) to changes in CVP in SICU patients receiving fluid boluses for volume resuscitation. MATERIALS AND METHODS: A prospective pilot study was conducted on a sample of SICU patients who met clinical indications for intravenous (IV) fluid bolus and who had preexisting central venous access. Boluses were standardized to crystalloid administration of either 500 mL over 30 min or 1,000 mL over 60 min, as clinically indicated. Concurrent measurements of venous CI (VCI) and CVP were conducted right before initiation of IV bolus (i.e. time 0) and then at 30 and 60 min (as applicable) after bolus initiation. Patient demographics, ventilatory parameters, and vital sign assessments were recorded, with descriptive outcomes reported due to the limited sample size. RESULTS: Twenty patients received a total of 24 IV fluid boluses. There were five recorded 500 mL boluses given over 30 min and 19 recorded 1,000 mL boluses given over 60 min. Mean (median) CVP measured at 0, 30, and 60 minutes post-bolus were 6.04 ± 3.32 (6.5), 9.00 ± 3.41 (8.0), and 11.1 ± 3.91 (12.0) mmHg, respectively. Mean (median) IVC-CI values at 0, 30, and 60 min were 44.4 ± 25.2 (36.5), 26.5 ± 22.8 (15.6), and 25.2 ± 21.2 (14.8), respectively. CONCLUSIONS: Observable changes in both VCI and CVP are apparent during an infusion of a standardized fluid bolus. Dynamic changes in VCI as a measurement of responsiveness to fluid bolus are inversely related to changes seen in CVP. Moreover, an IV bolus tends to produce an early response in VCI, while the CVP response is more gradual. Given the noninvasive nature of the measurement technique, VCI shows promise as a method of dynamically measuring patient response to fluid resuscitation. Further studies with larger sample sizes are warranted.

Sonographic evaluation of intravascular volume status: Can internal jugular or femoral vein collapsibility be used in the absence of IVC visualization?

INTRODUCTION: Inferior vena cava collapsibility index (IVC-CI) has been shown to correlate with both clinical and invasive assessment of intravascular volume status, but has important limitations such as the requirement for advanced sonographic skills, the degree of difficulty in obtaining those skills, and often challenging visualization of the IVC in the postoperative patient. The current study aims to explore the potential for using femoral (FV) or internal jugular (IJV) vein collapsibility as alternative sonographic options in the absence of adequate IVC visualization. METHODS: A prospective, observational study comparing IVC-CI and Fem- and/or IJV-CI was performed in two intensive care units (ICU) between January 2012 and April 2014. Concurrent M-mode measurements of IVC-CI and FV- and/or IJV-CI were collected during each sonographic session. Measurements of IVC were obtained using standard technique. IJV-CI and FV-CI were measured using high-frequency, linear array ultrasound probe placed in the corresponding anatomic areas. Paired data were analyzed using coefficient of correlation/determination and Bland-Altman determination of measurement bias. RESULTS: We performed paired ultrasound examination of IVC-IJV (n = 39) and IVC-FV (n = 22), in 40 patients (mean age 54.1; 40% women). Both FV-CI and IJV-CI scans took less time to complete than IVC-CI scans (both, P < 0.02). Correlations between IVC-CI/FV-CI (R(2) = 0.41) and IVC-CI/IJV-CI (R(2) = 0.38) were weak. There was a mean -3.5% measurement bias between IVC-CI and IJV-CI, with trend toward overestimation for IJV-CI with increasing collapsibility. In contrast, FV-CI underestimated collapsibility by approximately 3.8% across the measured collapsibility range. CONCLUSION: Despite small measurement biases, correlations between IVC-CI and FV-/IJV-CI are weak. These results indicate that IJ-CI and FV-CI should not be used as a primary intravascular volume assessment tool for clinical decision support in the ICU. The authors propose that IJV-CI and FV-CI be reserved for clinical scenarios where sonographic acquisition of both IVC-CI or subclavian collapsibility are not feasible, especially when trended over time. Sonographers should be aware that IJV-CI tends to overestimate collapsibility when compared to IVC-CI, and FV-CI tends to underestimates collapsibility relative to IVC-CI.