Contributions of mirror-image hair cell orientation to mouse otolith organ and zebrafish neuromast function.

Otolith organs in the inner ear and neuromasts in the fish lateral-line harbor two populations of hair cells oriented to detect stimuli in opposing directions. The underlying mechanism is highly conserved: the transcription factor EMX2 is regionally expressed in just one hair cell population and acts through the receptor GPR156 to reverse cell orientation relative to the other population. In mouse and zebrafish, loss of Emx2 results in sensory organs that harbor only one hair cell orientation and are not innervated properly. In zebrafish, Emx2 also confers hair cells with reduced mechanosensory properties. Here, we leverage mouse and zebrafish models lacking GPR156 to determine how detecting stimuli of opposing directions serves vestibular function, and whether GPR156 has other roles besides orienting hair cells. We find that otolith organs in Gpr156 mouse mutants have normal zonal organization and normal type I-II hair cell distribution and mechano-electrical transduction properties. In contrast, gpr156 zebrafish mutants lack the smaller mechanically-evoked signals that characterize Emx2-positive hair cells. Loss of GPR156 does not affect orientation-selectivity of afferents in mouse utricle or zebrafish neuromasts. Consistent with normal otolith organ anatomy and afferent selectivity, Gpr156 mutant mice do not show overt vestibular dysfunction. Instead, performance on two tests that engage otolith organs is significantly altered - swimming and off-vertical-axis rotation. We conclude that GPR156 relays hair cell orientation and transduction information downstream of EMX2, but not selectivity for direction-specific afferents. These results clarify how molecular mechanisms that confer bi-directionality to sensory organs contribute to function, from single hair cell physiology to animal behavior.

A critical view: Examining disparities regarding timely cholecystectomy.

BACKGROUND: Implicit bias may prevent patients with abdominal pain from receiving optimal workup and treatment. We hypothesized that patients from socially disadvantaged backgrounds would be more likely to experience delays in receiving operative treatment for cholecystitis. To study this question, we examined factors related to having a prior emergency department presentation for abdominal pain (prior emergency department visit) within 3 months of urgent cholecystectomy. METHODS: We performed a retrospective analysis of consecutive patients who received an urgent cholecystectomy at an urban safety net public hospital between July 2019 and December 2022. The main outcome of interest was prior emergency department visit within 3 months of index cholecystectomy. We examined patient age, sex, race, ethnicity, preferred language, insurance, and employment status. Bivariate comparisons and logistic regression were used to determine the relationship between patient factors and prior emergency department visit. RESULTS: Of 508 cholecystectomy patients, 138 (27.2%) had a prior emergency department visit in the 3 months preceding their surgery. In bivariate analysis, younger age, Black race, Hispanic ethnicity, non-English preferred language, and type of insurance (P < .05) were associated with prior emergency department visit. In regression, younger age, Black race, Hispanic ethnicity, and having Medicare or being uninsured were associated with higher odds of having a prior emergency department visit. CONCLUSION: More than 1 in 4 patients had an evaluation for abdominal pain within 3 months of having an urgent cholecystectomy, and these patients were more likely to be from socially disadvantaged backgrounds. Standardized evaluation pathways for abdominal pain are needed to reduce disparities from institutional or implicit bias.

Performance of trauma-trained large language models on surgical assessment questions: A new approach in resource identification.

BACKGROUND: Large language models have successfully navigated simulated medical board examination questions. However, whether and how language models can be used in surgical education is less understood. Our study evaluates the efficacy of domain-specific large language models in curating study materials for surgical board style questions. METHODS: We developed EAST-GPT and ACS-GPT, custom large language models with domain-specific knowledge from published guidelines from the Eastern Association of the Surgery of Trauma and the American College of Surgeons Trauma Quality Programs. EAST-GPT, ACS-GPT, and an untrained GPT-4 performance were assessed trauma-related questions from Surgical Education and Self-Assessment Program (18th edition). Large language models were asked to choose answers and provide answer rationales. Rationales were assessed against an educational framework with 5 domains: accuracy, relevance, comprehensiveness, evidence-base, and clarity. RESULTS: Ninety guidelines trained EAST-GPT and 10 trained ACS-GPT. All large language models were tested on 62 trauma questions. EAST-GPT correctly answered 76%, whereas ACS-GPT answered 68% correctly. Both models outperformed ChatGPT-4 (P < .05), which answered 45% correctly. For reasoning, EAST-GPT achieved the gratest mean scores across all 5 educational framework metrics. ACS-GPT scored lower than ChatGPT-4 in comprehensiveness and evidence-base; however, these differences were not statistically significant. CONCLUSION: Our study presents a novel methodology in identifying test-preparation resources by training a large language model to answer board-style multiple choice questions. Both trained models outperformed ChatGPT-4, demonstrating its answers were accurate, relevant, and evidence-based. Potential implications of such AI integration into surgical education must be explored.

Geriatric trauma triage: optimizing systems for older adults-a publication of the American Association for the Surgery of Trauma Geriatric Trauma Committee.

Background: Geriatric trauma patients are an increasing population of the United States (US), sustaining a high incidence of falls, and suffer greater morbidity and mortality to their younger counterparts. Significant variation and challenges exist to optimize outcomes for this cohort, while being mindful of available resources. This manuscript provides concise summary of locoregional and national practices, including relevant updates in the triage of geriatric trauma in an effort to synthesize the results and provide guidance for further investigation. Methods: We conducted a review of geriatric triage in the United States (US) at multiple stages in the care of the older patient, evaluating existing literature and guidelines. Opportunities for improvement or standardization were identified. Results: Opportunities for improved geriatric trauma triage exist in the pre-hospital setting, in the trauma bay, and continue after admission. They may include physiologic criteria, biochemical markers, radiologic criteria and even age. Recent Trauma Quality Improvement Program (TQIP) Best Practices Guidelines for Geriatric Trauma Management published in 2024 support these findings. Conclusion: Trauma systems must adjust to provide optimal care for older adults. Further investigation is required to provide pertinent guidance.

Mortality burden from variation in provision of surgical care in emergency general surgery: a cohort study using the National Inpatient Sample.

Background: The decision to undertake a surgical intervention for an emergency general surgery (EGS) condition (appendicitis, diverticulitis, cholecystitis, hernia, peptic ulcer, bowel obstruction, ischemic bowel) involves a complex consideration of factors, particularly in older adults. We hypothesized that identifying variability in the application of operative management could highlight a potential pathway to improve patient survival and outcomes. Methods: We included adults aged 65+ years with an EGS condition from the 2016-2017 National Inpatient Sample. Operative management was determined from procedure codes. Each patient was assigned a propensity score (PS) for the likelihood of undergoing an operation, modeled from patient and hospital factors: EGS diagnosis, age, gender, race, presence of shock, comorbidities, and hospital EGS volumes. Low and high probability for surgery was defined using a PS cut-off of 0.5. We identified two model-concordant groups (no surgery-low probability, surgery-high probability) and two model-discordant groups (no surgery-high probability, surgery-low probability). Logistic regression estimated the adjusted OR (AOR) of in-hospital mortality for each group. Results: Of 375 546 admissions, 21.2% underwent surgery. Model-discordant care occurred in 14.6%; 5.9% had no surgery despite a high PS and 8.7% received surgery with low PS. In the adjusted regression, model-discordant care was associated with significantly increased mortality: no surgery-high probability AOR 2.06 (1.86 to 2.27), surgery-low probability AOR 1.57 (1.49 to 1.65). Model-concordant care showed a protective effect against mortality (AOR 0.83, 0.74 to 0.92). Conclusions: Nearly one in seven EGS patients received model-discordant care, which was associated with higher mortality. Our study suggests that streamlined treatment protocols can be applied in EGS patients as a means to save lives. Level of evidence: III.

Scanning the aged to minimize missed injury: An EAST multicenter study.

BACKGROUND: Despite the high incidence of blunt trauma in older adults, there is a lack of evidence-based guidance for computed tomography (CT) imaging in this population. We aimed to identify an algorithm to guide use of a Pan-Scan (Head/C-spine/Torso) or a Selective Scan (Head/C-spine ± Torso). We hypothesized that a patient's initial history and exam could be used to guide imaging. METHODS: We prospectively studied blunt trauma patients aged 65+ at 18 Level I/II trauma centers. Patients presenting >24 h after injury or who died upon arrival were excluded. We collected history and physical elements and final injury diagnoses. Injury diagnoses were categorized into CT body regions of Head/C-spine or Torso (chest, abdomen/pelvis, and T/L spine). Using machine learning and regression modeling as well as a priori clinical algorithms based, we tested various decision rules against our dataset. Our priority was to identify a simple rule which could be applied at the bedside, maximizing sensitivity (Sens) and negative predictive value (NPV) to minimize missed injuries. RESULTS: We enrolled 5,498 patients with 3,082 injuries. Nearly half (47.1%, n = 2,587) had an injury within the defined CT body regions. No rule to guide a Pan-Scan could be identified with suitable Sens/NPV for clinical use. A clinical algorithm to identify patients for Pan-Scan, using a combination of physical exam findings and specific high-risk criteria, was identified and had a Sens of 0.94 and NPV of 0.86 This rule would have identified injuries in all but 90 patients (1.6%) and would theoretically spare 11.9% (655) of blunt trauma patients a torso CT. CONCLUSIONS: Our findings advocate for Head/Cspine CT in all geriatric patients with the addition of torso CT in the setting of positive clinical findings and high-risk criteria. Prospective validation of this rule could lead to streamlined diagnostic care of this growing trauma population. LEVEL OF EVIDENCE: Level 2, Diagnostic Tests or Criteria.

Advanced and alternative research methods for the acute care surgeon scientist.

Clinical research has evolved significantly over the last few decades to include many advanced and alternative study designs to answer unique questions. Recognizing a potential knowledge gap, the AAST Associate Member Council and Educational Development Committee created a research course at the 2022 Annual Meeting in Chicago to introduce junior researchers to these methodologies. This manuscript presents a summary of this AAST Annual Meeting session, and reviews topics including hierarchical modeling, geospatial analysis, patient-centered outcomes research, mixed methods designs, and negotiating complex issues in multicenter trials.

Frailty is associated with 90-day mortality in urgent thoracic surgery conditions.

Objective: In patients undergoing elective thoracic surgery, frailty is associated with worse outcomes. However, the magnitude by which frailty influences outcomes of urgent thoracic surgery (UTS) is unknown. Methods: We identified patients admitted with a UTS condition from January to September 2017 in the National Readmissions Database. UTS conditions were classified as esophageal perforation, hemo/pneumothorax, rib fracture, and obstructed hiatal hernia. Outcome of interest was mortality within 90 days of index admission. Frailty score was calculated using a deficit accumulation method. Cox proportional hazard modeling was used to calculate a hazard ratio for each combination of UTS disease type and frailty score, adjusted for sex, insurance payor, hospital size, and hospital and patient location, and was compared with the effect of frailty on elective lung lobectomy. Results: We identified 107,487 patients with a UTS condition. Among UTS conditions overall, increasing frailty elements were associated with increased mortality (hazard ratio, 2270; 95% CI, 1463-3523; P < .001). Compared with patients without frailty undergoing elective lobectomy, increasing frailty demonstrated trending toward increased mortality in all diagnoses. The magnitude of the effect of frailty on 90-day mortality differed depending on the disease and level of frailty. Conclusions: The effect of frailty on 90-day mortality after admission for urgent thoracic surgery conditions varies by disease type and level of frailty. Among UTS disease types, increasing frailty was associated with a higher 90-day risk of mortality. These findings suggest a valuable role for frailty evaluation in both clinical settings and administrative data for risk assessment.

Early Repair of Rib Fractures Is Associated with Superior Length of Stay and Total Hospital Cost: A Propensity Matched Analysis of the National Inpatient Sample.

Background and Objectives: Previous studies have suggested that early scheduling of the surgical stabilization of rib fractures (SSRF) is associated with superior outcomes. It is unclear if these data are reproducible at other institutions. We hypothesized that early SSRF would be associated with decreased morbidity, length of stay, and total charges. Materials and Methods: Adult patients who underwent SSRF for multiple rib fractures or flail chest were identified in the National Inpatient Sample (NIS) by ICD-10 code from the fourth quarter of 2015 to 2016. Patients were excluded for traumatic brain injury and missing study variables. Procedures occurring after hospital day 10 were excluded to remove possible confounding. Early fixation was defined as procedures which occurred on hospital day 0 or 1, and late fixation was defined as procedures which occurred on hospital days 2 through 10. The primary outcome was a composite outcome of death, pneumonia, tracheostomy, or discharge to a short-term hospital, as determined by NIS coding. Secondary outcomes were length of hospitalization (LOS) and total cost. Chi-square and Wilcoxon rank-sum testing were performed to determine differences in outcomes between the groups. One-to-one propensity matching was performed using covariates known to affect the outcome of rib fractures. Stuart-Maxwell marginal homogeneity and Wilcoxon signed rank matched pair testing was performed on the propensity-matched cohort. Results: Of the 474 patients who met the inclusion criteria, 148 (31.2%) received early repair and 326 (68.8%) received late repair. In unmatched analysis, the composite adverse outcome was lower among early fixation (16.2% vs. 40.2%, p < 0.001), total hospital cost was less (USD114k vs. USD215k, p < 0.001), and length of stay was shorter (6 days vs. 12 days) among early SSRF patients. Propensity matching identified 131 matched pairs of early and late SSRF. Composite adverse outcomes were less common among early SSRF (18.3% vs. 32.8%, p = 0.011). The LOS was shorter among early SSRF (6 days vs. 10 days, p < 0.001), and total hospital cost was also lower among early SSRF patients (USD118k vs. USD183k late, p = 0.001). Conclusion: In a large administrative database, early SSRF was associated with reduced adverse outcomes, as well as improved hospital length of stay and total cost. These data corroborate other research and suggest that early SSRF is preferred. Studies of outcomes after SSRF should stratify analyses by timing of procedure.

A Pathway for Increased Diversity, Equity, and Inclusion in the Surgical Infection Society.

Background: With the rise of diversity, equity, and inclusion (DEI) efforts across medicine, the Surgical Infection Society (SIS) leadership undertook a several-year mission to evaluate DEI issues within the SIS, through the formation of a DEI Ad Hoc Committee to guide the application of best practices. The purpose of this article is to describe the work of the DEI committee since its inception, as well as report on advances made during that time. Methods: Beginning in September 2020, 26 volunteer committee members met monthly to explore the current state of science and best practices around DEI, identify opportunities for the SIS, and translate opportunities into recommendations. As part of this initiative, a survey of the SIS membership was conducted. Survey results, published best practices from business and medicine, and experiences of committee members were utilized collaboratively to outline specific opportunities and recommendations. These findings were presented to the SIS Executive Council and to the membership at the SIS Annual Business Meeting. Results: Committee-identified opportunities and recommendations fell into broad categories of Membership, Leadership and Society Structure, the Annual Meeting, and Research Priorities. Several recommendations were immediately enacted, and a standing DEI committee was established to continue this work. Conclusions: Beyond the main mission of the SIS to advance the science of surgical infections, the SIS can also have a major impact on DEI within society and academic surgery at large.

Motor Vehicle Protective Device Usage Associated with Decreased Rate of Flail Chest: A Retrospective Database Analysis.

Background and Objectives: Protective equipment, including seatbelts and airbags, have dramatically reduced the morbidity and mortality rates associated with motor vehicle collisions (MVCs). While generally associated with a reduced rate of injury, the effect of motor vehicle protective equipment on patterns of chest wall trauma is unknown. We hypothesized that protective equipment would affect the rate of flail chest after an MVC. Materials and Methods: This study was a retrospective analysis of the 2019 iteration of the American College of Surgeons Trauma Quality Program (ACS-TQIP) database. Rib fracture types were categorized as non-flail chest rib fractures and flail chest using ICD-10 diagnosis coding. The primary outcome was the occurrence of flail chests after motor vehicle collisions. The protective equipment evaluated were seatbelts and airbags. We performed bivariate and multivariate logistic regression to determine the association of flail chest with the utilization of vehicle protective equipment. Results: We identified 25,101 patients with rib fractures after motor vehicle collisions. In bivariate analysis, the severity of the rib fractures was associated with seatbelt type, airbag status, smoking history, and history of cerebrovascular accident (CVA). In multivariate analysis, seatbelt use and airbag deployment (OR 0.76 CI 0.65-0.89) were independently associated with a decreased rate of flail chest. In an interaction analysis, flail chest was only reduced when a lap belt was used in combination with the deployed airbag (OR 0.59 CI 0.43-0.80) when a shoulder belt was used without airbag deployment (0.69 CI 0.49-0.97), or when a shoulder belt was used with airbag deployment (0.57 CI 0.46-0.70). Conclusions: Although motor vehicle protective equipment is associated with a decreased rate of flail chest after a motor vehicle collision, the benefit is only observed when lap belts and airbags are used simultaneously or when a shoulder belt is used. These data highlight the importance of occupant seatbelt compliance and suggest the effect of motor vehicle restraint systems in reducing severe chest wall injuries.

Prehospital tourniquet application in extremity vascular trauma: Improved functional outcomes.

BACKGROUND: Support for prehospital tourniquet use has increased, with recent data suggesting that tourniquet usage decreases shock without increasing limb complications. We hypothesized that prehospital tourniquet application in extremity vascular trauma, compared with no prehospital tourniquet application, is associated with lower rates of delayed amputation and better functional mobility. METHODS: We retrospectively studied adult patients with extremity vascular trauma at an urban civilian Level 1 trauma center (June 2016-May 2021). Outcomes of interest included delayed amputation and mobility at hospital discharge, measured by the Activity Measure for Post-Acute Care "6 Clicks" Basic Mobility Score. The "6 Clicks" Basic Mobility Score was documented by physical therapy; higher scores indicate more independent mobility. Injury mechanism, initial lactate, 24-hour transfusions, mortality, and acute kidney injury were also collected. Comparisons were performed using χ2 analysis and Fisher Exact and Wilcoxon rank-sum tests. RESULTS: Of 232 patients, prehospital tourniquet application was not associated with mortality or lactate level (both P > .05). The prehospital tourniquet application group had more transfusions, lower rates of acute kidney injury, and fewer delayed amputations (all P < .05). Ninety-one patients (45 prehospital tourniquet application and 46 without prehospital tourniquet application) were evaluated for "Moving between Bed and Chair" in the "6 Clicks" Basic Mobility Score, with patients in the prehospital tourniquet application group demonstrating higher levels of independence (P = .034). CONCLUSION: Prehospital tourniquet application was associated with favorable outcomes, including higher functional mobility and decreased delayed amputation. This suggests that tourniquet use should be encouraged in the civilian setting to improve outcomes and reduce the risk of limb loss.

A prospective assessment of resilience in trauma patients using the Connor-Davidson Resilience Scale.

BACKGROUND: Resilience, or the ability to adapt to difficult or challenging life experiences, may be an important mediator in trauma recovery. The primary aim of this study was to describe resilience levels for trauma patients using the validated Connor-Davidson Resilience Scale. METHODS: Adult trauma patients admitted to a Level 1 trauma center (June 2022-August 2022) were surveyed at the time of admission and by phone between 2 weeks and 1 month after the original survey to obtain follow-up scores. We utilized the validated Connor-Davidson Resilience Scale score, a 25-question survey with 5 subfactors (Tenacity, Positive Outlook, Social Support, Problem Solving, and Meaning and Purpose). Each question was scored from 0 to 4 (maximum score 100, representing the highest resilience). Patient factors were collected from the electronic medical record and trauma health registry. Wilcoxon signed-rank test and multivariable linear regression were used to understand associations with Connor-Davidson Resilience Scale scores. RESULTS: We enrolled 98 patients. The median age was 50 years (interquartile range 32-67), and 74% were male sex. The baseline median Connor-Davidson Resilience Scale score on admission was 88 (interquartile range 81-94). Follow-up surveys (N = 64) showed a median score of 89.5 (80-90.5) (P = non-significant). No demographic variable was significantly associated with increasing baseline Connor-Davidson Resilience Scale score. Increased length of stay (ß = 1.03), insurance (ß = -7.50), and unknown race (ß = 23.69) were correlated with follow-up Connor-Davidson Resilience Scale scores. The subfactor "Meaning and Purpose" decreased at follow-up but was not statistically significant (P = .05). CONCLUSION: Validated tools that can accurately distinguish variability in resilience scores are needed for the trauma patient population to understand its relationship with long-term patient health outcomes.

Associations Between Psychiatric Diagnoses on Length of Stay and Mortality After Rib Fracture: A Retrospective Analysis.

INTRODUCTION: Concurrent psychiatric diagnoses adversely impact outcomes in surgical patients, but their relationship to patients with rib fracture after trauma is less understood. We hypothesized that psychiatric comorbidity would be associated with increases in hospital length of stay (LOS) and mortality risk after rib fracture. MATERIALS AND METHODS: The 2017 National Inpatient Sample was queried for adult patients who were admitted with rib fracture after trauma. Mental health disorders were categorized into 34 psychiatric diagnosis groups (PDGs) using clinical classifications software refined for International Classification of Diseases-10. Outcomes of interest were LOS and mortality. Bivariable analysis determined associations between PDGs, patient demographics, hospital characteristics, and outcomes. Logistic regression was performed to identify adjusted effects on mortality, and linear regression was performed to identify effects on LOS. RESULTS: Of 32,801 patients, median age was 61 y (IQR 46-76), and median LOS was 5 d (IQR 3-9). No PDGs were associated with increased odds of mortality. Concurrent diagnosis of schizophrenia spectrum (Coeff. 3.5, 95% CI 2.7-4.4, P < 0.001) or trauma- or stressor-related (Coeff. 1.6, 95% CI 0.9-2.5, P < 0.001) disorders demonstrated the greatest association with prolonged LOS. Increased odds of death and prolonged hospital stay were also associated with male sex, non-White patient race, and surgery occurring at urban and public hospitals. CONCLUSIONS: Psychiatric comorbidities are associated with death after rib fracture but are associated with increased LOS. These findings may help promote multidisciplinary patient management in trauma.

In their own words: recovery after emergency general surgery in the older patient.

Objectives: Emergency general surgery (EGS) conditions, such as perforated intestines or complicated hernias, can lead to significant postoperative morbidity and mortality. We sought to understand the recovery experience of older patients at least 1 year after EGS to identify key factors for a successful long-term recovery. Methods: We conducted semi-structured interviews to explore recovery experiences of patients and their caregivers after admission for an EGS procedure. We screened patients who were aged 65 years or older at the time of an EGS operation, admitted at least 7 days, and still alive and able to consent at least 1 year postoperatively. We interviewed the patients, their primary caregiver, or both. Interview guides were developed to explore medical decision making, patient goals and expectations surrounding recovery after EGS, and to identify barriers and facilitators of recovery. Interviews were recorded and transcribed, and we used an inductive thematic approach to analysis. Results: We performed 15 interviews (11 patients and 4 caregivers). Patients wanted to return to their prior quality of life, or 'get back to normal.' Family was key in providing both instrumental support (eg, for daily tasks such as cooking, driving, wound care) and emotional support. Provision of temporary support was key to the recovery of many patients. Although most patients returned to their prior lifestyle, some also experienced depression, persistent abdominal effects, pain, or decreased stamina. When asked about medical decision making, patients expressed viewing the decision for having an operation not as a choice but, rather, the only rational option to treat a severe symptom or life-threating illness. Conclusions: There is an opportunity in healthcare to provide better education for older patients and their caregivers around instrumental and emotional support to bolster successful recovery after emergency surgery. Level of evidence: Qualitative study, level II.

Digital learning: The reach of podcasts and YouTube on trauma surgery education.

BACKGROUND: Physicians, medical students, and health care professionals are charged with staying current throughout their training. No studies have examined the scope of trauma surgery-related podcasts and videos. Our goal was to characterize and evaluate the growing number of trauma-related podcasts and YouTube channels. METHODS: We conducted a search across 3 podcasting platforms (Google Podcasts, Apple Podcasts, and Spotify) and 1 video-sharing site (YouTube) for podcasts published up to November 11, 2022. We queued platforms for "Trauma" and "Trauma Surgery." We included podcasts or video channels in English that focused on trauma surgery or trauma survivorship and recovery. Descriptive analyses were used to determine the characteristics of podcasts and YouTube channels, reported as counts. RESULTS: We identified 91 podcasts and 103 YouTube channels dedicated to trauma recovery and/or trauma surgery. The longest running podcast was the "TraumaCast," and the oldest YouTube channel was "TraumaPro." The podcast with the most episodes was "Trauma Therapist," and the YouTube channel with the most episodes was the Arizona Trauma Association. Podcasts were aimed at public audiences, whereas YouTube channels focused on providers. A large proportion of content is not created by licensed professionals. CONCLUSIONS: Our study shows that popular trauma-focused podcasts target the general population, not health care professionals. The content creators behind these digital platforms seek to educate the public on the recovery process after traumatic injury. We must better understand the advantages and pitfalls of these ubiquitous resources.

Single cell quantification of microRNA from small numbers of non-invasively sampled primary human cells.

Expression levels of microRNAs (miRNAs) in single cells are low and conventional miRNA detection methods require amplification that can be complex, time-consuming, costly and may bias results. Single cell microfluidic platforms have been developed; however, current approaches are unable to absolutely quantify single miRNA molecules expressed in single cells. Herein, we present an amplification-free sandwich hybridisation assay to detect single miRNA molecules in single cells using a microfluidic platform that optically traps and lyses individual cells. Absolute quantification of miR-21 and miR-34a molecules was achieved at a single cell level in human cell lines and validated using real-time qPCR. The sensitivity of the assay was demonstrated by quantifying single miRNA molecules in nasal epithelial cells and CD3+ T-cells, as well as nasal fluid collected non-invasively from healthy individuals. This platform requires ~50 cells or ~30 µL biofluid and can be extended for other miRNA targets therefore it could monitor miRNA levels in disease progression or clinical studies.

Redefining trauma deserts: novel technique to accurately map prehospital transport time.

Background: Prehospital transport time has been directly related to mortality for hemorrhaging trauma patients. 'Trauma deserts' were previously defined as being outside of a 5-mile radial distance of an urban trauma center. We postulated that the true 'desert' should be based on transport time rather than transport distance. Methods: Using the Chicagoland area that was used to describe 'trauma deserts,' a sequential process to query a commercial travel optimization product to map transport times over coordinates that covered the entire urban area at a particular time of day. This produces a heat map representing prehospital transport times. Travel times were then limited to 15 minutes to represent a temporally based map of transport capabilities. This was repeated during high and low traffic times and for centers across the city. Results: We demonstrated that the temporally based map for transport to a trauma center in an urban center differs significantly from the radial distance to the trauma center. Primary effects were proximity to highways and the downtown area. Transportation to centers were significantly different when time was considered instead of distance (p<0.001). We were further able to map variations in traffic patterns and thus transport times by time of day. The truly 'closest' trauma center by time changed based on time of day and was not always the closest hospital by distance. Discussion: As the crow flies is not how the ambulance drives. This novel technique of dynamically mapping transport times can be used to create accurate trauma deserts in an urban setting with multiple trauma centers. Further, this technique can be used to quantify the potential benefit or detriment of adding or removing firehouses or trauma centers.

What If We Do Not Operate? Outcomes of Nonoperatively Managed Emergency General Surgery Patients.

INTRODUCTION: Although two-thirds of patients with emergency general surgery (EGS) conditions are managed nonoperatively, their long-term outcomes are not well described. We describe outcomes of nonoperative management in a cohort of older EGS patients and estimate the projected risk of operative management using the NSQIP Surgical Risk Calculator (SRC). MATERIALS AND METHODS: We studied single-center inpatients aged 65 y and more with an EGS consult who did not undergo an operation (January 2019-December 2020). For each patient, we recorded the surgeon's recommendation as either an operation was "Not Needed" (medical management preferred) or "Not Recommended" (risk outweighed benefits). Our main outcome of interest was mortality at 30 d and 1 y. Our secondary outcome of interest was SRC-projected 30-day postoperative mortality risk (median % [interquartile range]), calculated using hypothetical low-risk and high-risk operations. RESULTS: We included 204 patients (60% female, median age 75 y), for whom an operation was "Not Needed" in 81% and "Not Recommended" in 19%. In this cohort, 11% died at 30 d and 23% died at 1 y. Mortality was higher for the "Not Recommended" cohort (37% versus 5% at 30 d and 53% versus 16% at 1 y, P < 0.05). The SRC-projected 30-day postoperative mortality risk was 3.7% (1.3-8.7) for low-risk and 5.8% (2-11.8) for high-risk operations. CONCLUSIONS: Nonoperative management in older EGS patients is associated with very high risk of short-term and long-term mortality, particularly if a surgeon advised that risks of surgery outweighed benefits. The SRC may underestimate risk in the highest-risk patients.