Acetone-Water Interactions in Crystalline and Amorphous Ice Environments.

We present research that systematically examines acetone interacting with various D2O ices of terrestrial and astrophysical interest using time-resolved, in situ reflection absorption infrared spectroscopy (RAIRS). We examine acetone deposited on top of different D2O ice films: high-density, nonporous amorphous (np-ASW), and crystalline (CI) films as well as porous amorphous (p-ASW) with various pore morphologies. Analysis of RAIR spectra changes after acetone exposure, and we find that more hydrogen bonding occurs between acetone and p-ASW ices as compared to acetone and np-ASW or CI ices. Hydrogen bonding quantification occurred by two independent RAIR spectral changes: a greater relative intensity of the 1703 cm-1 feature at low acetone coverage as part of a 14 cm-1 shift in the C═O region and an ∼30% integrated dangling bond area reduction after acetone exposure. Interestingly, when changing the water structure to be more porous (deposited at 70° compared to 30°), there is a further reduction in the amount of hydrogen bonding that occurs. This suggests that there is a lack of access to surface sites with dangling bonds in the pores as initial layers of acetone block the pores and acetone is unable to diffuse within the structure at low temperatures. In general, these results offer a clearer picture of the mechanisms that can occur when small organic hydrocarbons interact with various icy interfaces; a quantitative understanding of these interactions is essential for the accurate modeling of many astrophysical processes occurring on the surface of icy dust particles.

Gaining or wasting time? Influence of time to operating room on mortality after temporary hemostasis using resuscitative endovascular balloon occlusion of the aorta.

BACKGROUND: The optimal candidates for resuscitative endovascular balloon occlusion of the aorta (REBOA) remains unclear. We hypothesized patients with delayed transfer to operating room (OR) would benefit from REBOA. METHODS: Using the 2016-2017 ACS-TQIP database, patients were divided based on the transfer time to OR: ≤1 h (early) and >1 h (delayed). In each group, patients who underwent REBOA in emergency department (ED-REBOA) were matched with those without REBOA (non-REBOA) using propensity scores, and survival to discharge was compared. RESULTS: Among 163,453 patients, 114 and 138 patients (38 and 46 ED-REBOA) were included in the early and delayed groups, respectively. Survival to discharge was comparable between ED-REBOA and non-REBOA patients in the early group (39.5% vs. 48.7%, p = 0.35), whereas it was higher in ED-REBOA patients in the delayed group (39.1% vs. 12.0%, p < 0.01). CONCLUSIONS: Patients with delayed transfer to OR >1 h benefited from REBOA.

The influence of palladium on the hydrogenation of acetylene on Ag(111).

We have used reflection absorption infrared spectroscopy (RAIRS) and temperature programmed reaction (TPR) to study the selective hydrogenation of acetylene on both a clean Ag(111) surface and on a Pd/Ag(111) single-atom-alloy surface. The partial hydrogenation of acetylene to ethylene is an important catalytic process that is often carried out using PdAg alloys. It is challenging to study the reaction with ultrahigh vacuum techniques because H2 does not dissociate on Ag(111), and while H2 will dissociate at Pd sites, H-atom spillover from Pd to Ag sites does not generally occur. We bypassed the H2 dissociation step by exposing the surfaces to atomic hydrogen generated by the hot filament of an ion gauge. We find that hydrogen atoms react with acetylene to produce adsorbed ethylene at 85 K, the lowest temperature studied. This is revealed by the appearance of a RAIRS peak at 950 cm-1 due to the out-of-plane wagging mode of adsorbed ethylene when acetylene is exposed to a surface on which H atoms are pre-adsorbed. The formation of both ethylene and ethane are detected with TPR, but no acetylene coupling products, such as benzene, were found. From quantitative analysis of the TPR results, the percent conversion and selectivities to ethylene and ethane were determined. Low coverages of Pd enhance the conversion but do so mainly by increasing ethane formation.

Adsorption properties of acrolein, propanal, 2-propenol, and 1-propanol on Ag(111).

Reflection absorption infrared spectroscopy and temperature programmed desorption were used to study the adsorption of acrolein, its partial hydrogenation products, propanal and 2-propenol, and its full hydrogenation product, 1-propanol on the Ag(111) surface. Each molecule adsorbs weakly to the surface and desorbs without reaction at temperatures below 220 K. For acrolein, the out-of plane bending modes are more intense than the C[double bond, length as m-dash]O stretch at all coverages, indicating that the molecular plane is mainly parallel to the surface. The two alcohols, 2-propenol and 1-propanol, have notably higher desorption temperatures than acrolein and display strong hydrogen bonding in the multilayers as revealed by a broadened and redshifted O-H stretch. For 1-propanol, annealing the surface to 180 K disrupts the hydrogen-bonding to produce unusally narrow peaks, including one at 1015 cm-1 with a full width at half maximum of 1.1 cm-1. This suggests that 1-propanol forms a highly orderded monolayer and adsorbs as a single conformer. For 2-propenol, hydrogen bonding in the multilayer correlates with observation of the C[double bond, length as m-dash]C stretch at 1646 cm-1, which is invisible for the monolayer. This suggests that for monolayer coverages, 2-propenol bonds with the C[double bond, length as m-dash]C bond parallel to the surface. Similarly, the C[double bond, length as m-dash]O stretch of propanal is very weak for low coverages but becomes the largest peak for the multilayer, indicating a change in orientation with coverage.

Delays in Surgical Intervention and Temporary Hemostasis Using Resuscitative Endovascular Balloon Occlusion of the aorta (REBOA): Influence of Time to Operating Room on Mortality.

BACKGROUND: The optimal candidates for resuscitative endovascular balloon occlusion of the aorta (REBOA) remain unclear. We hypothesized that patients who experience delays in surgical intervention would benefit from REBOA. METHODS: Using the Japan Trauma Databank (2014-2019), patients transferred to the operating room (OR) within 3 h were identified. Patients treated with REBOA were matched with those without REBOA using propensity scores, and further divided based on the transfer time to OR: ≤ 1 h (early), 1-2 h (delayed), and >2 h (significantly-delayed). Survival to discharge was compared. RESULTS: Among 5258 patients, 310 underwent REBOA. In 223 matched pairs, patients treated with REBOA had improved survival (56.5% vs. 31.8%; p < 0.01), although in-hospital mortality was reduced by REBOA only in the delayed and significantly-delayed subgroups (HR = 0.43 [0.28-0.65] and 0.42 [0.25-0.71]). CONCLUSIONS: REBOA-treated trauma patients who experience delays in surgical intervention (>1 h) have improved survival.

Level 1 Trauma Centers and OEF/OIF Emergency Departments: Comparison of Trauma Patient Populations.

INTRODUCTION: Brooke Army Medical Center (BAMC), the largest military hospital and the only level 1 trauma center in the DoD, cares for active duty, retired uniformed services personnel, and beneficiaries. In addition, BAMC works in collaboration with the Southwest Texas Regional Advisory Council (STRAC) and University Hospital (UH), San Antonio's other level 1 trauma center, to provide trauma care to residents of the city and 22 counties in southwest Texas from San Antonio to Mexico (26,000 square mile area). Civilian-military partnerships are shown to benefit the training of military medical personnel; however, to date, there are no published reports specific to military personnel experiences within emergency care. The purpose of the current study was to describe and compare the emergency department trauma patient populations of two level 1 trauma centers in one metropolitan city (BAMC and UH) as well as determine if DoD level 1 trauma cases were representative of patients treated in OEF/OIF emergency department settings. MATERIALS AND METHODS: We obtained a nonhuman subjects research determination for de-identified data from the US Air Force 59th Medical Wing and the University of Texas Health Science Center at San Antonio Institutional Review Boards. Data on emergency department patients treated between the years 2015 and 2017 were obtained from the two level 1 trauma centers (BAMC and UH, located in San Antonio, Texas); data included injury descriptors, ICU and hospital days, and department procedures. RESULTS: Two-proportion Z-tests indicated that trauma patients were similar across trauma centers on injury type, injury severity, and discharge status; yet trauma patients differed significantly in terms of mechanism of injury and regions of injury. BAMC received significantly greater proportions of patients injured from falls, firearms and with facial and head injuries than UH, which received significantly greater proportion of patients with thorax and abdominal injuries. In addition, a significantly greater proportion of patients spent more than 2 days in the ICU and greater than two total hospital days at BAMC than in UH. In comparison to military emergency departments in combat zones, BAMC had significantly lower rates of blood product administration and endotracheal intubations. CONCLUSIONS: The trauma patients treated at a military level 1 trauma center were similar to those treated in the civilian level 1 trauma center in the same city, indicating the effectiveness of the only DoD Level 1 trauma center to provide experience comparable to that provided in civilian trauma centers. However, further research is needed to determine if the exposure rates to specific procedures are adequate to meet predeployment readiness requirements.

Secondary Overtriage in Patients with Complicated Mild Traumatic Brain Injury: An Observational Study and Socioeconomic Analysis of 1447 Hospitalizations.

BACKGROUND: Secondary overtriage is a problematic phenomenon because it creates unnecessary expense and potentially results in the mismanagement of healthcare resources. The rates of secondary overtriage among patients with complicated mild traumatic brain injury (cmTBI) are unknown. OBJECTIVE: To determine the rate of secondary overtriage among patients with cmTBI using the institutional trauma registry. METHODS: An observational study using retrospective analysis of 1447 hospitalizations including all consecutive patients with cmTBI between 2004 and 2013. Data on age, sex, race/ethnicity, insurance status, GCS, Injury Severity Score (ISS), Trauma Injury Severity Score, transfer mode, overall length of stay (LOS), LOS within intensive care unit, and total charges were collected and analyzed. RESULTS: Overall, the rate of secondary overtriage among patients with cmTBI was 17.2%. These patients tended to be younger (median: 41 vs 60.5 yr; P < .001), have a lower ISS (9 vs 16; P < .001), and were more likely to be discharged home or leave against medical advice. CONCLUSION: Our findings provide evidence to the growing body of literature suggesting that not all patients with cmTBI need to be transferred to a tertiary care center. In our study, these transfers ultimately incurred a total cost of $13 294 ($1337 transfer cost) per patient.

Reaction pathways for HCN on transition metal surfaces.

The adsorption and decomposition of HCN on the Pd(111) and Ru(001) surfaces have been studied with reflection absorption infrared spectroscopy and density functional theory calculations. The results are compared to earlier studies of HCN adsorption on the Pt(111) and Cu(100) surfaces. In all cases the initial adsorption at low temperatures gives rise to a ν(C-H) stretch peak at ∼3300 cm-1, which is very close to the gas phase value indicating that the triple CN bond is retained for the adsorbed molecule. When the Pd(111) surface is heated to room temperature, the HCN is converted to the aminocarbyne species, CNH2, which was also observed on the Pt(111) surface. DFT calculations confirm the high stability of CNH2 on Pd(111), and suggest a bi-molecular mechanism for its formation. When HCN on Cu(100) is heated, it desorbs without reaction. In contrast, no stable intermediates are detected on Ru(001) as the surface is heated, indicating that HCN decomposes completely to atomic species.

Application of electronic medical record-derived analytics in critical care: Rothman Index predicts mortality and readmissions in surgical intensive care unit patients.

INTRODUCTION: The Rothman Index (RI) is an objective measurement of a patient's overall condition, automatically generated from 26 variables including vital signs, laboratory data, cardiac rhythms, and nursing assessments. The purpose of this study was to assess the validity of RI scores in predicting surgical ICU (SICU) readmission rates and mortality. METHODS: We conducted a single-center retrospective analysis of surgical patients who were transferred from the SICU to the surgical floor from December 2014 to December 2016. Data included demographics, length of stay (LOS), mortality, and RI at multiple pretransfer and post-transfer time points. RESULTS: A total of 1,445 SICU patients were transferred to the surgical floor; 79 patients (5.5%) were readmitted within 48 hours of transfer. Mean age was 52 years, and 67% were male. Compared to controls, patients readmitted to the SICU within 48 hours experienced higher LOS (29 vs. 11 days, p < 0.05) as well as higher mortality (2.5% vs. 0.6%, p < 0.05). Patients requiring readmission also had a lower RI at 72, 48, and 24 hours before transfer as well as at 24 and 48 hours after transfer (p < 0.05 for all). Rothman Index scores were categorized into higher-risk (<40), medium-risk (40-65), and lower-risk groups (>65); RI scores at 24 hours before transfer were inversely proportional to overall mortality (RI < 40 = 2.5%, RI 40-65 = 0.3%, and RI > 65 = 0%; p < 0.05) and SICU readmission rates (RI < 40 = 9%, RI 40-65 = 5.2%, and RI > 65 = 2.8%; p < 0.05). Patients transferred with RI scores greater than 83 did not require SICU readmission within 48 hours. CONCLUSION: Surgical ICU patients requiring readmission within 48 hours of transfer have a significantly higher mortality and longer LOS compared to those who do not. Patients requiring readmission also have significantly lower pretransfer and post-transfer RI scores compared to those who do not. Rothman Index scores may be used as a clinical tool for evaluating patients before transfer from the SICU. Prospective studies are warranted to further validate use of this technology. LEVEL OF EVIDENCE: Retrospective database review, level III.

Colon Trauma: Evidence-Based Practices.

Colon injury is not uncommon and occurs in about a half of patients with penetrating hollow viscus injuries. Despite major advances in the operative management of penetrating colon wounds, there remains discussion regarding the appropriate treatment of destructive colon injuries, with a significant amount of scientific evidence supporting segmental resection with primary anastomosis in most patients without comorbidities or large transfusion requirement. Although literature is sparse concerning the management of blunt colon injuries, some studies have shown operative decision based on an algorithm originally defined for penetrating wounds should be considered in blunt colon injuries. The optimal management of colonic injuries in patients requiring damage control surgery (DCS) also remains controversial. Studies have recently reported that there is no increased risk compared with patients treated without DCS if fascial closure is completed on the first reoperation, or that a management algorithm for penetrating colon wounds is probably efficacious for colon injuries in the setting of DCS as well.

Compensatory Reserve Index: Performance of A Novel Monitoring Technology to Identify the Bleeding Trauma Patient.

INTRODUCTION: Hemorrhage is one of the most substantial causes of death after traumatic injury. Standard measures, including systolic blood pressure (SBP), are poor surrogate indicators of physiologic compromise until compensatory mechanisms have been overwhelmed. Compensatory Reserve Index (CRI) is a novel monitoring technology with the ability to assess physiologic reserve. We hypothesized CRI would be a better predictor of physiologic compromise secondary to hemorrhage than traditional vital signs. METHODS: A prospective observational study of 89 subjects meeting trauma center activation criteria at a single level I trauma center was conducted from October 2015 to February 2016. Data collected included demographics, SBP, heart rate, and requirement for hemorrhage-associated, life-saving intervention (LSI) (i.e., operation or angiography for hemorrhage, local or tourniquet control of external bleeding, and transfusion >2 units PRBC). Receiver-operator characteristic (ROC) curves were formulated and appropriate thresholds were calculated to compare relative value of the metrics for predictive modeling. RESULTS: For predicting hemorrhage-related LSI, CRI demonstrated a sensitivity of 83% and a negative predictive value (NPV) of 91% as compared with SBP with a sensitivity to detect hemorrhage of 26% (P < 0.05) and an NPV of 78%. ROC curves generated from admission CRI and SBP measures demonstrated values of 0.83 and 0.62, respectively. CRI identified significant hemorrhage requiring potentially life-saving therapy more reliably than SBP (P < 0.05). CONCLUSION: The CRI device demonstrated superior capacity over systolic blood pressure in predicting the need for posttraumatic hemorrhage intervention in the acute resuscitation phase after injury.

Resource Utilization After Snakebite Severity Score Implementation into Treatment Algorithm of Crotaline Bite.

BACKGROUND: Crotaline envenomation clinical manifestations vary considerably among patients. Current recommendations for treatment with Crotalidae polyvalent immune Fab require assessment of envenomation control. Determining control of envenomation, particularly when patients are evaluated by different providers in separate clinical settings, can be difficult. OBJECTIVE: To determine if a difference in total vials of Crotalidae antivenin therapy exists between pre-protocol and post-Snakebite Severity Score (SSS) protocol. METHODS: Retrospective medical record review at an academic medical and regional Level I trauma center. Resource utilization in patients with a diagnosis of "snakebite" was compared between patients treated pre- and post-SSS protocol implementation. RESULTS: One hundred forty-six patients were included in the evaluation. One hundred twenty-seven (87.0%) patients received antivenin, n = 80 (90.9%) in the pre-protocol group and n = 47 (81.0%) in the post-protocol group. Median total number of antivenin vials per patient was lower in the post-protocol group than the pre-protocol group, 16 (10-24 interquartile range) vs. 12 (10-16 interquartile range), p = 0.006. This decreased utilization correlates to an approximate $13,200 savings per patient. Hospital and intensive care unit length of stay, opioid use, incidence of blood product transfusion, need for surgical intervention, or need for intubation were not different between groups. CONCLUSIONS: A snakebite protocol with SSS utilization to guide antivenin administration results in significantly decreased antivenin therapy in snakebite patients without increase in other health care utilization.

Comparison of compensatory reserve and arterial lactate as markers of shock and resuscitation.

BACKGROUND: During traumatic hemorrhage, the ability to identify shock and intervene before decompensation is paramount to survival. Lactate is extremely sensitive to shock, and its clearance has been demonstrated a useful gauge of shock and resuscitation status. Though lactate can be measured in the field, logistical constraints render it impractical in certain environments. The compensatory reserve represents a new clinical measurement reflecting the remaining capacity to compensate for hypoperfusion. We hypothesized the compensatory reserve index (CRI) would be an effective surrogate marker of shock and resuscitation compared to lactate. METHODS: The CRI device was placed on consecutive patients meeting trauma center activation criteria and remained on the patient until discharge, admission, or transport to operating suite. All subjects had a lactate level measured as part of their routine admission metabolic analysis. Time-corresponding CRI and lactate values were matched in regards to initial and subsequent lactate levels. Mean time from lactate sample collection to data availability in the electronic medical record was calculated. Predictive capacity of CRI and lactate in predicting hemorrhage was determined by receiver-operator characteristic curve analysis. Correlation analysis was performed to determine if any association existed between changing CRI and lactate values. RESULTS: Receiver-operator characteristic (ROC) curves were generated and area under the curve was 0.8052 and 0.8246 for CRI and lactate, respectively. There was no significant difference in each parameter's ability to predict hemorrhage (p = 0.8015). The mean duration from lactate sample collection to clinical availability was 44 minutes whereas CRI values were available immediately. Analysis of the concomitant change in serial CRI and lactate levels revealed a Spearman's correlation coefficient of -0.73 (p < 0.01). CONCLUSION: CRI performed with equivalent predictive capacity to lactate with respect to identifying initial perfusion status associated with hemorrhage and subsequent resuscitation. LEVEL OF EVIDENCE: Diagnostic, Level II.

Organ Donation, an Unexpected Benefit of Aggressive Resuscitation of Trauma Patients Presenting Dead on Arrival.

BACKGROUND: We sought to determine whether aggressive resuscitation in trauma patients presenting without vital signs, or "dead on arrival," was futile. We also sought to determine whether organ donation was an unexpected benefit of aggressive resuscitation. STUDY DESIGN: We conducted a review of adults presenting to our Level I trauma center with no signs of life (pulse = 0 beats/min; systolic blood pressure = 0 mmHg; and no evidence of neurologic activity, Glasgow Coma Scale score = 3). Primary end point was survival to hospital discharge or major organ donation (ie heart, lung, kidney, liver, or pancreas were harvested). We compared our survival rates with those of the National Trauma Data Bank in 2012. Patient demographics, emergency department vital signs, and outcomes were analyzed. RESULTS: Three hundred and forty patients presented with no signs of life to our emergency department after injury (median Injury Severity Score = 40). There were 7 survivors to discharge, but only 5 (1.5%) were functionally independent (4 were victims of penetrating trauma). Of the 333 nonsurvivors, 12 patients (3.6%) donated major organs (16 kidneys, 2 hearts, 4 livers, and 2 lungs). An analysis of the National Trauma Data Bank yielded a comparable survival rate for those presenting dead on arrival, with an overall survival rate of 1.8% (100 of 5,384); 2.3% for blunt trauma and 1.4% for penetrating trauma. CONCLUSIONS: Trauma patients presenting dead on arrival rarely (1.5%) achieve functional independence. However, organ donation appears to be an under-recognized outcomes benefit (3.6%) of the resuscitation of injury victims arriving without vital signs.

Imaging and radiation effects of gold nanoparticles in tumour cells.

Gold nanoparticle radiosensitization represents a novel technique in enhancement of ionising radiation dose and its effect on biological systems. Variation between theoretical predictions and experimental measurement is significant enough that the mechanism leading to an increase in cell killing and DNA damage is still not clear. We present the first experimental results that take into account both the measured biodistribution of gold nanoparticles at the cellular level and the range of the product electrons responsible for energy deposition. Combining synchrotron-generated monoenergetic X-rays, intracellular gold particle imaging and DNA damage assays, has enabled a DNA damage model to be generated that includes the production of intermediate electrons. We can therefore show for the first time good agreement between the prediction of biological outcomes from both the Local Effect Model and a DNA damage model with experimentally observed cell killing and DNA damage induction via the combination of X-rays and GNPs. However, the requirement of two distinct models as indicated by this mechanistic study, one for short-term DNA damage and another for cell survival, indicates that, at least for nanoparticle enhancement, it is not safe to equate the lethal lesions invoked in the local effect model with DNA damage events.

Mass Casualty Incident Management Preparedness: A Survey of the American College of Surgeons Committee on Trauma.

Mass casualty incidents (MCIs) are events resulting in more injured patients than hospital systems can handle with standard protocols. Several studies have assessed hospital preparedness during MCIs. However, physicians and trauma surgeons need to be familiar with their hospital's MCI Plan. The purpose of this survey was to assess hospitals' and trauma surgeon's preparedness for MCIs. Online surveys were e-mailed to members of the American College of Surgeons committee on Trauma Ad Hoc Committee on Disaster and Mass Casualty Management before the March 2012 meeting. Eighty surveys were analyzed (of 258). About 76 per cent were American College of Surgeons Level I trauma centers, 18 per cent were Level II trauma centers. Fifty-seven per cent of Level I and 21 per cent of Level II trauma centers had experienced an MCI. A total of 98 per cent of respondents thought it was likely their hospital would see a future MCI. Severe weather storm was the most likely event (95%), followed by public transportation incident (86%), then explosion (85%). About 83 per cent of hospitals had mechanisms to request additional physician/surgeons, and 80 per cent reported plans for operative triage. The majority of trauma surgeons felt prepared for an MCI and believed an event was likely to occur in the future. The survey was limited by the highly select group of respondents and future surveys will be necessary.

Novel markers predict death and organ failure following hemorrhagic shock.

BACKGROUND: ADAMTS 13, sP-Selectin and HSP27 have been investigated as potential prognostic markers in patients with hemorrhagic shock. METHODS: This study was part of a double-blind, randomized, parallel-group, controlled trial and included seventeen trauma patients presented to ED with severe hemorrhagic. The sera for testing were collected from these patients at the time of admission. Investigators and laboratory personnel performing testing were blinded to the patients' identity and clinical course. RESULTS: The prognostic value of ADAMTS13, sP-Selectin, and HSP27 was compared to prognostic value of systolic blood pressure (SBP), base deficit estimation (BD), heart rate (HR), shock index (SI) and tissue oxygen saturation (StO2) by constructing the receiver operation characteristics (ROC). The area under the curve (AUC) of the ROC for HSP27 (0.92) was greater than for SBP (0.45), BD (0.89), HR (0.61), SI (0.45) and StO2 (0.46). AUC for sP-Selectin (0.86) and for ADAMTS13 antigen (0.74) were comparable with BD one, but greater than for the rest of currently used tests. CONCLUSION: Serum concentrations of ADAMTS13, HSP27 and sP-Selectin measured during the admission, appear to be comparable to or better than SBP, BD, SI, HR and StO2 in predicting MODS and death after hemorrhage from trauma. These potential new markers deserve further investigation.