Identifying patients at imminent risk of death is critical in the management of trauma patients. This study measures the vital sign thresholds associated with death among trauma patients.

This study included data from patients ≥15 years of age in the American College of Surgeons Trauma Quality Improvement Program (TQIP) database. Patients with vital signs of zero were excluded. Documented prehospital and emergency department (ED) vital signs included systolic pressure, heart rate, respiratory rate, and calculated shock index (SI). The area under the receiver operator curves (AUROC) was used to assess the accuracy of these variables for predicting 24-hour survival. Optimal thresholds to predict mortality were identified using Youden’s Index, 90% specificity, and 90% sensitivity. Additional analyses examined patients 70+ years of age.

There were 1,439,221 subjects in the 2019-2020 datasets that met inclusion for this analysis with <0.1% (10,270) who died within 24 hours. The optimal threshold for prehospital systolic pressure was 110, pulse rate was 110, SI was 0.9, and respiratory rate was 15. The optimal threshold for the ED systolic was 112, pulse rate was 107, SI was 0.9, and respiratory rate was 21. Among the elderly sub-analysis, the optimal threshold for prehospital systolic was 116, pulse rate was 100, SI was 0.8, and respiratory rate was 21. The optimal threshold for ED systolic was 121, pulse rate was 95, SI was 0.8, and respiratory rate was 21.

Systolic blood pressure (SBP) and SI offered the best predictor of mortality among trauma patients. The SBP values predictive of mortality were significantly higher than the traditional 90mmHg threshold. This dataset highlights the need for better methods to guide resuscitation as initial vital signs have limited accuracy in predicting subsequent mortality.

The aim of this study was to describe the sensitivity of various C-reactive protein (CRP) cut-off values to identify patients requiring magnetic resonance imaging evaluation for pyogenic spinal infection among emergency department (ED) adults presenting with neck or back pain.

We prospectively enrolled a convenience series of adults presenting to a community ED with neck or back pain in whom ED providers had concern for pyogenic spinal infection in a derivation cohort from 2004 to 2010 and a validation cohort from 2010 to 2018. The validation cohort included only patients with pyogenic spinal infection. We analysed diagnostic test characteristics of various CRP cut-off values.

We enrolled 232 patients and analysed 201 patients. The median age was 55 years, 43.8% were male, 4.0% had history of intravenous drug use, and 20.9% had recent spinal surgery. In the derivation cohort, 38 (23.9%) of 159 patients had pyogenic spinal infection. Derivation sensitivity and specificity of CRP cut-off values were > 3.5 mg/L (100%, 24.8%), > 10 mg/L (100%, 41.3%), > 30 mg/L (100%, 61.2%), and > 50 mg/L (89.5%, 69.4%). Validation sensitivities of CRP cut-off values were > 3.5 mg/L (97.6%), > 10 mg/L (97.6%), > 30 mg/L (90.4%), and > 50 mg/L (85.7%).

CRP cut-offs beyond the upper limit of normal had high sensitivity for pyogenic spinal infection in this adult ED population. Elevated CRP cut-off values of 10 mg/L and 30 mg/L require validation in other settings.

Ventilation with a bag valve mask (BVM) is a challenging but critical skill for airway management in the prehospital setting.

Tidal volumes received during single rescuer ventilation with a modified BVM with supplemental external handle will be higher than those delivered using a standard BVM among health care volunteers in a manikin model.

This study was a randomized crossover trial of adult health care providers performing ventilation on a manikin. Investigators randomized participants to perform single rescuer ventilation, first using either a BVM modified by addition of a supplemental external handle or a standard unmodified BVM (Spur II BVM device; Ambu; Ballerup, Denmark). Participants performed mask placement and delivery of 10 breaths per minute for three minutes, as guided by a metronome. After a three-minute rest period, they performed ventilation using the alternative device. The primary outcome measure was mean received tidal volume as measured by the manikin (IngMar RespiTrainer model; IngMar Medical; Pittsburgh, Pennsylvania USA). Secondary outcomes included subject device preference.

Of 70 recruited participants, all completed the study. The difference in mean received tidal volume between ventilations performed using the modified BVM with external handle versus standard BVM was 20 ml (95% CI, -16 to 56 ml; P=.28). There were no significant differences in mean received tidal volume based on the order of study arm allocation. The proportion of participants preferring the modified BVM over the standard BVM was 47.1% (95% CI, 35.7 to 58.6%).

The modified BVM with added external handle did not result in greater mean received tidal volume compared to standard BVM during single rescuer ventilation in a manikin model.

ReedP, ZobristB, CasmaerM, SchauerSG, KesterN, AprilMD. Single Rescuer Ventilation Using a Bag Valve Mask with Removable External Handle: A Randomized Crossover Trial. Prehosp Disaster Med. 2017;32(6):625–630.

Mass-casualty (MASCAL) events are known to occur in the combat setting. There are very limited data at this time from the Joint Theater (Iraq and Afghanistan) wars specific to MASCAL events. The purpose of this report was to provide preliminary data for the development of prehospital planning and guidelines.

Cases were identified using the Department of Defense (DoD; Virginia USA) Trauma Registry (DoDTR) and the Prehospital Trauma Registry (PHTR). These cases were identified as part of a research study evaluating Tactical Combat Casualty Care (TCCC) guidelines. Cases that were designated as or associated with denoted MASCAL events were included.

Fifty subjects were identified during the course of this project. Explosives were the most common cause of injuries. There was a wide range of vital signs. Tourniquet placement and pressure dressings were the most common interventions, followed by analgesia administration. Oral transmucosal fentanyl citrate (OTFC) was the most common parenteral analgesic drug administered. Most were evacuated as “routine.” Follow-up data were available for 36 of the subjects and 97% were discharged alive.

The most common prehospital interventions were tourniquet and pressure dressing hemorrhage control, along with pain medication administration. Larger data sets are needed to guide development of MASCAL in-theater clinical practice guidelines.

SchauerSG, AprilMD, SimonE, MaddryJK, CarterR III, DelorenzoRA. Prehospital Interventions During Mass-Casualty Events in Afghanistan: A Case Analysis. Prehosp Disaster Med. 2017;32(4):465–468.

Specification of appropriate personal protective equipment for respiratory protection against influenza is somewhat controversial. In a clinical environment, N95 filtering facepiece respirators (FFRs) are often recommended for respiratory protection against infectious aerosols. This study evaluates the ability of N95 FFRs to capture viable H1N1 influenza aerosols.

Five N95 FFR models were challenged with aerosolized viable H1N1 influenza and inert polystyrene latex particles at continuous flow rates of 85 and 170 liters per minute. Virus was assayed using Madin-Darby canine kidney cells to determine the median tissue culture infective dose (TCID50). Aerosols were generated using a Collison nebulizer containing H1N1 influenza virus at 1 × 108 TCID50/mL. To determine filtration efficiency, viable sampling was performed upstream and downstream of the FFR.

N95 FFRs filtered 0.8-μm particles of both H1N1 influenza and inert origins with more than 95% efficiency. With the exception of 1 model, no statistically significant difference in filtration performance was observed between influenza and inert particles of similar size. Although statistically significant differences were observed for 2 models when comparing the 2 flow rates, the differences have no significance to protection.

This study empirically demonstrates that a National Institute for Occupational Safety and Health-approved N95 FFR captures viable H1N1 influenza aerosols as well as or better than its N95 rating, suggesting that a properly fitted FFR reduces inhalation exposure to airborne influenza virus. This study also provides evidence that filtration efficiency is based primarily on particle size rather than the nature of the particle's origin.