The relationship between intraosseous catheter tip placement, flow rates, and infusion pressures in a high bone density cadaveric swine (Sus scrofa) model.

Background: Intraosseous (IO) infusion is a life-preserving technique when intravenous access is unobtainable. Successful IO infusion requires sufficiently high flow rates to preserve life but at low enough pressures to avoid complications. However, IO catheter tips are often misplaced, and the relative flow rates and pressures between IO catheter tips placed in medullary, trabecular, and cortical bone are not well described, which has important implications for clinical practice. Objectives: We developed the Zone Theory of IO Catheter Tip Placement based on bone density and proximity to the venous central sinus and then tested the influence of catheter tip placement locations on flow rates and pressures in a cadaveric swine model. Methods: Three cross-trained participants infused 500 mL of crystalloid fluid into cadaveric swine humerus and sternum (N = 210 trials total) using a push‒pull method with a 60 cm3 syringe. Computed tomography scans were scored by radiologists and categorized as zone 1 (medullary space), zone 2 (trabecular bone), or zone 3 (cortical bone) catheter tip placements. Differences between zones in flow rates, mean pressures, and peak pressures were assessed using analysis of variance and analysis of covariance to account for participant and site differences at the p < 0.05 threshold. Results: Zone 1 and zone 2 placements were essentially identical in flow rates, mean pressures, and peak pressures (each p > 0.05). Zone 1 and zone 2 placements were significantly higher in flow rates and lower in pressures than zone 3 placements (each p < 0.05 or less). Conclusion: Within the limitations of an unpressurized cadaveric swine model, the present findings suggest that IO catheter tip placements need not be perfect to acquire high flow rates at low pressures, only accurate enough to avoid the dense cortical bone of zone 3. Future research using in vivo animal and human models is needed to better define the clinical impact of IO catheter placement on infusion flow rates and pressures.

Serious bacterial infection risk in recently immunized febrile infants in the emergency department.

STUDY OBJECTIVES: Fever following immunizations is a common presenting chiefcomplaint among infants. The 2021 American Academy of Pediatrics (AAP) febrile infant clinical practice guidelines exclude recently immunized (RI) infants. This is a challenge for clinicians in the management of the febrile RI young infant. The objective of this study was to assess the prevalence of SBI in RI febrile young infants between 6 and 12 weeks of age. METHODS: This was a retrospective chart review of infants 6-12 weeks who presented with a fever ≥38 °C to two U.S. military academic Emergency Departments over a four-year period. Infants were considered recently immunized (RI) if they had received immunizations in the preceding 72 h prior to evaluation and not recently immunized (NRI) if they had not received immunizations during this time period. The primary outcome was prevalence of serious bacterial infection (SBI) further delineated into invasive-bacterial infection (IBI) and non-invasive bacterial infection (non-IBI) based on culture and/or radiograph reports. RESULTS: Of the 508 febrile infants identified, 114 had received recent immunizations in the preceding 72 h. The overall prevalence of SBI was 11.4% (95% CI = 8.9-14.6) in our study population. The prevalence of SBI in NRI infants was 13.7% (95% CI = 10.6-17.6) compared to 3.5% (95% CI = 1.1-9.3) in RI infants. The relative risk of SBI in the setting of recent immunizations was 0.3 (95% CI = 0.1-0.7). There were no cases of invasive-bacterial infections (IBI) in the RI group with all but one of the SBI being urinary tract infections (UTI). The single non-UTI was a case of pneumonia in an infant who presented with respiratory symptoms within 24 h of immunizations. CONCLUSION: The risk of IBI (meningitis or bacteremia) in RI infants aged 6 to 12 weeks is low. Non-IBI within the first 24 h following immunization was significantly lower than in febrile NRI infants. UTIs remain a risk in the RI population and investigation with urinalysis and urine culture should be encouraged. Shared decision making with families guide a less invasive approach to the care of these children. Future research utilizing a large prospective multi-center data registry would aid in further defining the risk of both IBI and non-IBI among RI infants.

Prescreened Whole O Blood Group Walking Blood Bank Capabilities for Nontraditional Maritime Medical Receiving Platforms: A Case Series.

BACKGROUND: Tactical Combat Casualty Care (TCCC) guidelines recognize low-titer group O whole blood (LTOWB) as the resuscitative fluid of choice for combat wounded. Utilization of prescreened LTOWB in a walking blood bank (WBB) format has been well described by the Ranger O low-titer blood (ROLO) and the United States Marine Corps Valkyrie programs, but it has not been applied to the maritime setting. METHODS: We describe three WBB experiences of an expeditionary resuscitative surgical system (ERSS) team, attached to three nontraditional maritime medical receiving platforms, over 6 months. RESULTS: Significant variations were identified in the number of screened eligible donors, the number of LTOWB donors, and the timely arrival at WBB activation sites between the platforms. Overall, 95% and 84% of the screened eligible group O blood donors on the Arleigh Burke Class Destroyer (DDG) and Nimitz Class Aircraft Carrier (CVN), respectively, were determined to be LTOWB. However, only 37% of the eligible screened group O blood donors aboard the Harper's Ferry Class Dock Landing Ship (LSD) were found to be LTOWB. Of the eligible donors, 66% did not complete screening, with 52% citing a correctable reason for nonparticipation. CONCLUSION: LTOWB attained through WBBs may be the only practical resuscitative fluid on maritime platforms without inherent blood product storage capabilities to perform remote damage control resuscitation. Future efforts should focus on optimizing WBBs through capability development, education, and training efforts.

Application Times, Placement Accuracy, and User Ratings of Commercially Available Manual and Battery-Powered Intraosseous Catheters in a High Bone Density Cadaveric Swine Model.

INTRODUCTION: Intraosseous (IO) infusion, the pressurized injection of fluids into bone through a catheter, is a life-preserving resuscitative technique for treating trauma patients with severe hemorrhage. However, little is known regarding the application times, placement accuracy, and end-user ratings of battery-powered and manual IO access devices. This study was specifically designed to fill these knowledge gaps on six FDA-approved IO access devices. MATERIALS AND METHODS: Three experienced U.S. Navy Emergency Medicine residents each placed commercially available 15-gauge IO catheters in cadaveric swine (Sus scrofa) proximal humeri and sternums in a randomized prospective experimental design. Devices included the battery-powered EZ-IO Rapid Infuser and the manual Jamshidi IO, PerSys NIO, SAM Manual IO, Tactical Advanced Lifesaving IO Needle (TALON), and PYNG First Access for Shock and Trauma 1 (30 trials per device, 10 per user, 210 total trials). Application times, placement accuracy in medullary (zone 1) and trabecular (zone 2) bone while avoiding cortical (zone 3) bone, and eight subjective user ratings were analyzed using ANOVA and nonparametric statistics at P < .05. RESULTS: The EZ-IO demonstrated the fastest application times, high rates in avoiding zone 3, and the highest user ratings (P < .0001). The TALON conferred intermediate placement times, highest rates of avoiding zone 3, and second-highest user ratings. The SAM Manual IO and Jamshidi performed poorly, with mixed results for the PerSys NIO and PYNG First Access for Shock and Trauma 1. CONCLUSIONS: The battery-powered EZ-IO performed best and remains the IO access device of choice. The present findings suggest that the TALON should be considered as a manual backup to the EZ-IO.

Determining Intraosseous Needle Placement Using Point-of-Care Ultrasound in a Swine (Sus scrofa) Model.

OBJECTIVE: Intraosseous (IO) access is critical in resuscitation, providing rapid access when peripheral vascular attempts fail. Unfortunately, misplacement commonly occurs, leading to possible fluid extravasation and tissue necrosis. Current research exploring the utility of bedside ultrasound in confirming IO line placement is limited by small sample sizes of skeletally immature subjects or geriatric cadaveric models. The objective of this study was to investigate the potential value of ultrasound confirming IO needle placement in a live tissue model with bone densities approximated to the young adult medical or trauma patient. MATERIALS AND METHODS: In this randomized, blinded prospective study, IO devices were placed into the bilateral humeri of 36 sedated adult swine (N = 72) with bone densities approximating that of a 20-39-year-old adult. Of the 72 lines, 53 were randomized to the IO space ("correct") and 19 into the subcutaneous tissue ("incorrect"). Four emergency physicians with variable ultrasound experience and blinded to needle location independently assessed correct or incorrect needle placements based on the presence of an intramedullary "flare" on color power Doppler (CPD) during a saline flush. Participants adjusted the ultrasound beam trajectory and recorded assessments up to three times, totaling 204 separate observations. RESULTS: Overall, sensitivity for placement confirmation was 72% (95% CI: 64%-79%). Specificity was 79% (95% CI: 66%-89%). First assessment and final assessment results were similar. More experienced sonographers demonstrated greater success in identifying inaccurate placements with a specificity of 86% (95% CI: 63%-96%). CONCLUSION: Within the context of this study, point-of-care ultrasound with CPD did not reliably confirm IO line placement. However, more accurate assessments of functional and malpositioned catheters were noted in sonographers with greater than 4 years of experience. Future study into experienced sonographers' use of CPD to confirm IO catheter placement is needed.

Performance comparison of intraosseous devices and setups for infusion of whole blood in a cadaveric swine bone model.

OBJECTIVES: Intraosseous (IO) access can provide a critical bridge for blood product infusion when peripheral venous access is not obtainable. Successful pressurized IO infusion requires flow rates sufficient to preserve life, but with infusion pressures low enough to avoid clinical complications (e.g., hemolysis, bone damage, fat emboli). However, the optimal method for pressured IO delivery of blood was unknown. METHODS: Three trained physicians infused 500 mL of whole blood through a 15-gauge, 45 mm IO catheter into fresh, high bone density cadaveric swine proximal humeri. Participants applied eight different pressure infusion strategies: (1) gravity, (2) pressure bag, (3) pressure bag actively maintained at or above 300 mmHg, (4) hand pump, (5) hand pump with pressure bag, (6) push-pull with 10 mL syringe, (7) push-pull with 60 mL syringe, and a (8) Manual Rapid Infuser in a randomized within-subjects design (30 trials per method, 240 trials total). The primary outcomes of flow rates, mean and peak pressures, and user ratings were contrasted using ANOVA at p < 0.05. RESULTS: The Manual Rapid Infuser conferred the highest flow rates (199 ± 3 mL/min) and most favorable user ratings, but also the highest mean and peak pressures. Push-pull conferred the next highest flow rates (67 ± 5 mL/min for 60 mL, 56 ± 2 mL/min for 10 mL) and pressures, with intermediate-to-high user ratings. Hand pump flow rates were essentially identical with (45 ± 4 mL/min) or without (44 ± 3 mL/min) pressure bag, with high user ratings without a pressure bag. Pressure bag and gravity methods conferred low flow rates and user ratings. CONCLUSIONS: Some pressured IO infusion methods can achieve flow rates adequate to serve as a resuscitative bridge in the massively hemorrhaged trauma victim, but flow rates and pressures vary greatly across IO pressurized infusion methods. Manual Rapid Infuser and push-pull methods conferred high flow rates but also relatively high pressures, highlighting the importance of using in vivo models in future research to assess the possible clinical complications of using these promising methods. Combined, present findings highlight the importance of studying pressurized IO methods towards preserving the life of the critically injured trauma victim.

Fluid Resuscitation in Tactical Combat Casualty Care; TCCC Guidelines Change 21-01. 4 November 2021.

Hemorrhagic shock in combat trauma remains the greatest life threat to casualties with potentially survivable injuries. Advances in external hemorrhage control and the increasing use of damage control resuscitation have demonstrated significant success in decreasing mortality in combat casualties. Presently, an expanding body of literature suggests that fluid resuscitation strategies for casualties in hemorrhagic shock that include the prehospital use of cold-stored or fresh whole blood when available, or blood components when whole blood is not available, are superior to crystalloid and colloid fluids. On the basis of this recent evidence, the Committee on Tactical Combat Casualty Care (TCCC) has conducted a review of fluid resuscitation for the combat casualty who is in hemorrhagic shock and made the following new recommendations: (1) cold stored low-titer group O whole blood (CS-LTOWB) has been designated as the preferred resuscitation fluid, with fresh LTOWB identified as the first alternate if CS-LTOWB is not available; (2) crystalloids and Hextend are no longer recommended as fluid resuscitation options in hemorrhagic shock; (3) target systolic blood pressure (SBP) resuscitation goals have been redefined for casualties with and without traumatic brain injury (TBI) coexisting with their hemorrhagic shock; and (4) empiric prehospital calcium administration is now recommended whenever blood product resuscitation is required.

Single Versus Double Anatomic Site Intraosseous Blood Transfusion in a Swine Model of Hemorrhagic Shock.

BACKGROUND: Blood transfusion via single site intraosseous access is a critical modality when caring for a trauma victim that lacks intravascular access. Flow rates and potential clinical complications when utilizing two sites of intraosseous access are not well known. MATERIALS AND METHODS: Anesthetized adult female Yorkshire swine (Sus scrofa; n = 48; 76.7 ± 1.75kg; range 66-90kg) were cannulated and then bled approximately 30% total blood volume. Swine were randomly assigned to treatment groups: single sited humerus, single sited sternum, dual sited humerus or dual sited humerus and sternum. Flow rates, hemolysis, physiologic measurements, biochemical variables, and pulmonary histologic inflammation and occlusion were contrasted between groups. RESULTS: Dual sited intraosseous transfusion flow rates (128ml/min, 95% CI 123-132) were double the flow rates of single sites (65ml/min, 95% CI 60-70), P < .0001.Single sited humeral flow rates were greater than sternal flow rates, with respective averages of 74ml/min and 55ml/min, though not reaching statistical significance (P < 0.17). There was no significant elevation of plasma free hemoglobin in any group after transfusion as compared to baseline (P = 0.7). Groups did not significantly differ in vitals or biochemical variables. Most pulmonary specimens had some intraparenchymal fat embolism, however no animals had evidence of occlusive intra-arterial fat embolism. CONCLUSIONS: Dual anatomic site, pressure bag driven, intraosseous blood transfusion approximately doubles flow rates without evidence of clinical complications or hemolysis. Further research using a survivability model is needed to characterize long-term complications from pressurized IO transfusions.

Rapid Sequence Induction Strategies Among Critically Injured U.S. Military During the Afghanistan and Iraq Conflicts.

INTRODUCTION: Rapid sequence intubation of patients experiencing traumatic hemorrhage represents a precarious phase of care, which can be marked by hemodynamic instability and pulseless arrest. Military combat trauma guidelines recommend reduced induction dose and early blood product resuscitation. Few studies have evaluated the role of induction dose and preintubation transfusion on hemodynamic outcomes. We compared rates of postintubation systolic blood pressure (SBP) of < 70 mm Hg, > 30% drop in SBP, pulseless arrest, and mortality at 24 hours and 30 days among patients who did and did not receive blood products before intubation and then examined if induction agent and dose influenced the same outcomes. MATERIALS AND METHODS: A retrospective analysis was performed of battle-injured personnel presenting to surgical care facilities in Iraq and Afghanistan between 2004 and 2018. Those who received blood transfusions, underwent intubation, and had an Injury Severity Score of ≥15 were included. Intubation for primary head, facial, or neck injury, burns, operative room intubations, or those with cardiopulmonary resuscitation in progress were excluded. Multivariable logistic regression was performed with unadjusted and adjusted odds ratios for the five study outcomes among patients who did and did not receive preintubation blood products. The same analysis was performed for patients who received full or excessive versus partial induction agent dose. RESULTS: A total of 153 patients had a mean age of 24.9 (SD 4.5), Injury Severity Score 29.7 (SD 11.2), heart rate 122.8 (SD 24), SBP 108.2 (SD 26.6). Eighty-one (53%) patients received preintubation blood products and had similar characteristics to those who did not receive transfusions. Adjusted multivariate analysis found odds ratios as follows: 30% SBP decrease 9.4 (95% CI 2.3-38.0), SBP < 70 13.0 (95% CI 3.3-51.6), pulseless arrest 18.5 (95% CI 1.2-279.3), 24-hour mortality 3.8 (95% CI 0.7-21.5), and 30-day mortality 1.3 (0.4-4.7). In analysis of induction agent choice and comparison of induction agent dose, no statistically significant benefit was seen. CONCLUSION: Within the context of this historical cohort, the early use of blood products conferred a statistically significant benefit in reducing postintubation hypotension and pulseless arrest among combat trauma victims exposed to traumatic hemorrhage. Induction agent choice and dose did not significantly influence the hemodynamic or mortality outcomes.

The Use of Tranexamic Acid in Tactical Combat Casualty Care: TCCC Proposed Change 20-02.

The literature continues to provide strong support for the early use of tranexamic acid (TXA) in severely injured trauma patients. Questions persist, however, regarding the optimal medical and tactical/logistical use, timing, and dose of this medication, both from the published TXA literature and from the TCCC user community. The use of TXA has been explored outside of trauma, new dosing strategies have been pursued, and expansion of retrospective use data has grown as well. These questions emphasize the need for a reexamination of TXA by the CoTCCC. The most significant updates to the TCCC Guidelines are (i) including significant traumatic brain injury (TBI) as an indication for TXA, (ii) changing the dosing protocol to a single 2g IV/IO administration, and (iii) recommending TXA administration via slow IV/IO push.

COVID-19 pneumonia with hemoptysis: Acute segmental pulmonary emboli associated with novel coronavirus infection.

Recent retrospective studies from Wuhan, China suggest Novel Coronavirus Disease 2019 (COVID-19) may be associated with a hypercoagulable state and increased risk for venous thromboembolism. The overlap in the signs and symptoms of COVID-19 associated Acute Respiratory Distress Syndrome (ARDS) and COVID-19 with concurrent pulmonary embolism creates a diagnostic challenge for emergency medicine physicians in patients already at risk for renal impairment. However, identifying features atypical for COVID-19 alone may play a role in the judicious use of Computed Tomography Angiography among these patients. Hemoptysis is seen in roughly 13% of pulmonary embolism cases and infrequently reported among COVID-19 infections. Additionally, the presence of right heart strain on electrocardiography (EKG) is a well described clinical presentations of pulmonary embolism not reported commonly with COVID-19 infections.

Intravenous and Intraosseous Blood Transfusion With Three Different Pediatric Pressure Transfusion Strategies in an Immature Swine (Sus scrofa) Model of Hemorrhagic Shock: A Pilot Study.

INTRODUCTION: Exsanguination remains the leading cause of preventable death in military conflicts, and pediatric casualties are common. Transfusion is crucial to preserve life, but vascular access is challenging in children, so intraosseous (IO) access is often required. However, the optimal transfusion method is unclear. There was therefore the need for feasibility testing of a model for contrasting the efficacy of blood infusion devices via intravenous (IV) and IO access in immature swine with bone densities similar to children. MATERIALS AND METHODS: Eighteen immature swine (21 ± 1 kg) were bled 31% of estimated blood volume and then received autologous blood delivered by pressure bag, push-pull (PP), or LifeFlow Rapid Infuser via IO (15-gauge IO needle placed in the humeral head) or IV (auricular 20-gauge), with monitoring for 60 minutes. RESULTS: Flow rates for LifeFlow (172 ± 28 mL/kg) were 4-fold higher than pressure bag (44 ± 13 mL/kg, P < 0.001) and 80% higher than PP (95 ± 28 mL/kg, P < 0.02). However, higher hemolysis was evident in the IV LifeFlow condition, with 6-fold more plasma-free hemoglobin than other conditions (P < 0.0001). CONCLUSIONS: IV LifeFlow conferred higher flows, but higher hemolysis in this pilot study demonstrates the feasibility of an immature swine model toward determining optimal methods for resuscitating children with hemorrhagic shock.

Safety of Pressurized Intraosseous Blood Infusion Strategies in a Swine Model of Hemorrhagic Shock.

BACKGROUND: Current guidelines support intraosseous access for trauma resuscitation when intravenous access is not readily available. However, safety of intraosseous blood transfusions with varying degrees of infusion pressure has not been previously characterized. MATERIALS AND METHODS: Adult female Yorkshire swine (Sus scrofa; n = 36; mean (M): 80 kg, 95% CI: 78-82 kg) were cannulated and then bled approximately 30% total blood volume. Swine were randomly assigned to proximal humerus intraosseous blood infusion with either Rapid Infuser, or Pressure Bag, or Push-Pull methods (n = 12 each). Flow rates, infusion pressures, vitals, biochemical variables, and pulmonary and renal tissue pathology were contrasted between groups. RESULTS: Flow rates were greater for the Push-Pull strategy than Pressure Bag (96.5 mL/min versus 72.6 mL/min, P = 0.02) or Rapid Infuser (96.5 mL/min versus 60 mL/min, P = 0.002) strategies. The pressures generated during the Push-Pull transfusion (3058 mmHg) were greater than the other strategies (≤360 mmHg). After the observation period, plasma-free hemoglobin levels were higher in the Push-Pull strategy than in the Rapid Infuser (40 mg/dL versus 12 mg/dL, P = 0.02) or Pressure Bag (40 mg/dL versus 12 mg/dL, P = 0.01). Groups did not significantly differ in vitals, biochemical variables, or tissue pathology. CONCLUSIONS: Push-Pull conferred the highest flow rates, but with higher infusion pressures and evidence of intravascular hemolysis. Rapid Infuser and Pressure Bag infusions had no increase from baseline in plasma-free hemoglobin. Pressure Bag infusion was noted to confer an advantage in flow rates over Rapid Infuser. Intraosseous blood transfusion with pressure bags can safely bridge toward central access in the early phases of trauma resuscitation.

Inflammatory markers limitations in the diagnosis of pediatric calcaneal osteomyelitis.

Calcaneal osteomyelitis is an uncommon, but clinically important emergent condition in the differential of the limping child. Early recognition is paramount to prevent complications from delayed diagnosis like formation of periosteal abscesses or growth plate injury. The diagnosis of pediatric osteoarticular infection relies on a combination of clinical exam, imaging and inflammatory markers. Erythrocyte sedation rate (ESR) and C-reactive protein (CRP) have reported sensitivities for osteomyelitis of 94% and 95%, respectively. However, clinicians should be aware that certain clinical factors can decrease the reliability of inflammatory markers in this pediatric condition. Location of infection in small bones like the calcaneus can lead to significantly lower sensitivities than in long bones. Pretreatment with antibiotics prior presentation can also decrease the reliability of ESR and CRP. In this case, we highlight two unique clinical factors that diminish the sensitivity of commonly used inflammatory markers in the diagnosis of pediatric osteomyelitis.

Bilateral tibial tubercle avulsion fractures: A pediatric orthopedic injury at high risk for compartment syndrome.

Adolescent tibial tubercle avulsion fractures represent an uncommon, but clinically significant condition for emergency medicine physicians. Early recognition of the signs and symptoms of this pediatric orthopedic diagnosis are important, as anterior compartment syndrome can occur in up to 10-20% of cases. Anterior tibial tubercle fractures are generally sport related injuries, occurring primarily in otherwise healthy adolescent males between the ages of 11-17. They account for less than 3% of all epiphyseal injuries in this age group and are rarely bilateral in nature. In this article, we present a case with two unique clinical features: bilateral sports related tibial tubercle avulsion fractures and subsequent development of bilateral clinical compartment syndrome. We briefly review the risk factors, presentation, and diagnosis of this rare but clinically important condition.

Comparison of pediatric post-reduction fluoroscopic- and ultrasound forearm fracture images.

OBJECTIVE: Emergency department (ED) reduction of pediatric fractures occurs most commonly in the forearm and can be challenging if fluoroscopy is not available. We sought to assess the ability of point of-care ultrasonography (POCUS) to predict adequacy of reduction by fluoroscopy. METHODS: We prospectively enrolled ED patients 0-17 years of age with radial and/or ulnar fractures requiring reduction under fluoroscopic guidance. Post-reduction POCUS (probe dorsal, volar, and coronal) and fluoroscopic (AP and lateral) fracture images were recorded. Fracture angles were compared between blinded POCUS and fluoroscopic measurements and between POCUS measurements by a blinded emergency physician and a blinded radiologist, reporting mean differences and 95% confidence intervals. We calculated sensitivity, specificity, and likelihood ratios of POCUS in the prediction of fluoroscopically detected post-reduction malalignment, as interpreted by a blinded pediatric orthopaedist. RESULTS: The 58 patients were 7.9 ±â€¯3.5 years of age and had 21 radial (36%), 1 ulnar (2%), and 36 radioulnar (62%) fractures. Fluoroscopy and POCUS angles were within a mean of 0.1°-3.2°, depending on the site and surface measured. Radiologist- and emergency physician-interpreted POCUS measurements were within a mean of 1° in all dimensions. POCUS identified inadequate reductions with 100% sensitivity and 92-93% specificity. CONCLUSIONS: Blinded emergency medicine and radiology interpretations of post-reduction POCUS fracture images agree closely. Post-reduction POCUS measurements are comparable to those obtained by fluoroscopy and accurately predict adequacy of reduction. POCUS can be used to guide pediatric fracture reduction when bedside fluoroscopy is not available in the ED.

The non-visualized appendix and secondary signs on ultrasound for pediatric appendicitis in the community hospital setting.

BACKGROUND: Secondary signs of appendicitis on ultrasound may aid with diagnosis in the setting of a non-visualized appendix (NVA). This role has not been shown in the community hospital setting. MATERIALS AND METHODS: All right lower quadrant ultrasounds performed in children for clinical suspicion of appendicitis over a 5-year period in a single community hospital were evaluated. Secondary signs of inflammation including free fluid, ileus, fat stranding, abscess, and lymphadenopathy were documented. Patients were followed for 1 year for the primary outcome of appendicitis. These data were analyzed to determine the utility of secondary signs in the diagnosis of acute appendicitis when an NVA is reported. RESULTS: Six hundred and seventeen ultrasounds were reviewed; 470 of these had an NVA. Of NVAs, 47 (10%) of patients were diagnosed with appendicitis. Sensitivity and specificity of having at least one secondary were 38.3% and 80%, respectively. The positive and negative predictive values of having at least one secondary sign were 17.3% and 92%, respectively. CONCLUSION: These data suggest that the absence of secondary signs has a strong negative predictive value for appendicitis in the community hospital setting; however, the full utility of secondary signs may be limited in this setting.

A Pilot Study of Four Intraosseous Blood Transfusion Strategies.

BACKGROUND: Intraosseous (IO) access is used by military first responders administering fluids, blood, and medications. Current IO transfusion strategies include gravity, pressure bags, rapid transfusion devices, and manual push-pull through a three-way stopcock. In a swine model of hemorrhagic shock, we compared flow rates among four different IO blood transfusion strategies. METHODS: Nine Yorkshire swine were placed under general anesthesia. We removed 20 to 25mL/kg of each animal's estimated blood volume using flow of gravity. IO access was obtained in the proximal humerus. We then autologously infused 10 to 15mL/kg of the animal's estimated blood volume through one of four randomly assigned treatment arms. RESULTS: The average weight of the swine was 77.3kg (interquartile range, 72.7kg-88.8kg). Infusion rates were as follows: gravity, 5mL/min; Belmont rapid infuser, 31mL/min; single-site pressure bag, 78mL/min; double-site pressure bag, 103mL/min; and push-pull technique, 109mL/min. No pulmonary arterial fat emboli were noted. CONCLUSION: The optimal IO transfusion strategy for injured Servicemembers appears to be single-site transfusion with a 10mL to 20mL flush of normal saline, followed immediately by transfusion under a pressure bag. Further study, powered to detect differences in flow rate and clinical complications. is required.