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1.
Ann Surg ; 277(3): 512-519, 2023 03 01.
Article in English | MEDLINE | ID: mdl-34417368

ABSTRACT

OBJECTIVES: ABRUPT was a prospective, noninterventional, observational study of resuscitation practices at 21 burn centers. The primary goal was to examine burn resuscitation with albumin or crystalloids alone, to design a future prospective randomized trial. SUMMARY BACKGROUND DATA: No modern prospective study has determined whether to use colloids or crystalloids for acute burn resuscitation. METHODS: Patients ≥18 years with burns ≥ 20% total body surface area (TBSA) had hourly documentation of resuscitation parameters for 48 hours. Patients received either crystalloids alone or had albumin supplemented to crystalloid based on center protocols. RESULTS: Of 379 enrollees, two-thirds (253) were resuscitated with albumin and one-third (126) were resuscitated with crystalloid alone. Albumin patients received more total fluid than Crystalloid patients (5.2 ± 2.3 vs 3.7 ± 1.7 mL/kg/% TBSA burn/24 hours), but patients in the Albumin Group were older, had larger burns, higher admission Sequential Organ Failure Assessment (SOFA) scores, and more inhalation injury. Albumin lowered the in-to-out (I/O) ratio and was started ≤12 hours in patients with the highest initial fluid requirements, given >12 hours with intermediate requirements, and avoided in patients who responded to crystalloid alone. CONCLUSIONS: Albumin use is associated with older age, larger and deeper burns, and more severe organ dysfunction at presentation. Albumin supplementation is started when initial crystalloid rates are above expected targets and improves the I/O ratio. The fluid received in the first 24 hours was at or above the Parkland Formula estimate.


Subject(s)
Albumins , Fluid Therapy , Humans , Isotonic Solutions/therapeutic use , Prospective Studies , Retrospective Studies , Treatment Outcome , Crystalloid Solutions/therapeutic use , Albumins/therapeutic use , North America
2.
Am J Emerg Med ; 66: 135-140, 2023 04.
Article in English | MEDLINE | ID: mdl-36753929

ABSTRACT

INTRODUCTION: Indications for hospitalization in patients with parafalcine or tentorial subdural hematomas (SDH) remain unclear. This study derived and validated a clinical decision rule to identify patients at low risk for complications such that hospitalization can be avoided. METHODS: A multicenter retrospective medical record review of adult patients with parafalcine or tentorial SDHs was completed. The primary outcome was significant injury, defined as injury that led to neurosurgery, discharge to another facility, or death. A multivariable logistic regression was performed to identify variables independently associated with the outcome in the derivation cohort. These variables were then validated on a separate cohort from a different institution abstracted without knowledge of the identified variables. RESULTS: In the derivation cohort, 134 patients with parafalcine/tentorial SDHs were identified. The mean age was 63 ± 19 years with 82 (61%) male. Seventy-one (53%) had significant injuries. Variables independently associated with significant injury included: age over 60, adjusted odds ratio (aOR) 3.46 (95% CI 1.24, 9.62), initial Glasgow Coma Scale score below 15, aOR =7.92 (95% CI 2.78, 22.5), and additional traumatic brain injuries (TBIs) on computerized tomography (CT), aOR =5.97 (95% CI 2.48, 14.4). These three variables had a sensitivity of 71/71 (100%, 95% CI 96, 100%) and specificity of 12/63 (19%, 95% CI 10, 31%). The validation cohort (n = 83) had a mean age of 62 ± 22 years with 50 (60%) male. The three variables had a sensitivity of 36/36 (100%, 95% CI 92, 100%) and specificity of 7/47 (15%, 95% CI 6.2, 28%). All 39 (100%, 95% CI 93, 100%) patients from both cohorts who underwent neurosurgery had additional TBI findings on their CT scan. CONCLUSIONS: Patients with parafalcine/tentorial SDHs who are under 60 years with initial GCS scores of 15 and no addition TBIs on CT are at low risk and may not need hospitalization. Furthermore, patients with isolated parafalcine/tentorial SDHs are unlikely to undergo neurosurgery. Prospective, external validation with a larger sample size is now recommended. STUDY TYPE: Retrospective Cohort Study.


Subject(s)
Brain Injuries, Traumatic , Hematoma, Subdural , Adult , Humans , Male , Middle Aged , Aged , Aged, 80 and over , Female , Retrospective Studies , Prospective Studies , Hematoma, Subdural/diagnostic imaging , Hematoma, Subdural/surgery , Hematoma, Subdural/complications , Brain Injuries, Traumatic/complications , Risk Factors , Glasgow Coma Scale
3.
Am J Emerg Med ; 51: 384-387, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34823195

ABSTRACT

BACKGROUND: Emergency physicians (EP) are frequently interrupted to screen electrocardiograms (ECG) from Emergency Department (ED) patients undergoing triage. Our objective was to identify discrepancies between the computer ECG interpretation and the cardiologist ECG interpretation and if any patients with normal ECGs underwent emergent cardiac intervention. We hypothesized that computer-interpreted normal ECGs do not require immediate review by an EP. METHODS: This was a retrospective study of adult (≥ 18 years old) ED patients with computer-interpreted normal ECGs. Laboratory, diagnostic testing and clinical outcomes were abstracted following accepted methodologic guidelines. The primary outcome was emergent cardiac catheterization (within four hours of ED arrival). All ECGs underwent final cardiologist interpretation. When cardiology interpretation differed from the computer (discrepant ECG interpretation), the difference was classified as potentially clinically significant or not clinically significant. Data was described with simple descriptive statistics. MAIN FINDINGS: 989 ECGs interpreted as normal by the computer were analyzed with a mean age of 50.4 ± 16.8 years (range 18-96 years) and 527 (53%) female. Discrepant ECG interpretations were identified in 184 cases including 124 (12.5%, 95% CI 10.4, 14.7%) not clinically significant and 60 (6.1%, 95% CI 4.6, 7.7%) potentially clinically significant. The 60 potentially clinically significant changes included: ST/T wave changes 45 (75%), T wave inversions 6 (10%), prolonged QT 3 (5%), and possible ischemia 10 (17%). Of these 60, 21 (35%) patients were admitted. Six patients had potassium levels >6.0 mEq/L, with one having a potentially clinically significant ECG change. No patient (0%, 95% CI 0, 0.3%) underwent immediate (within four hours) cardiac catherization whereas two underwent delayed cardiac interventions. CONCLUSIONS: Cardiologists frequently disagree with a computer-interpreted normal ECG. Patients with computer-interpreted normal ECGs, however, rarely had significant ischemic events. A rare number of patients will have important cardiac outcomes regardless of the computer-generated normal ECG interpretation. Immediate EP review of the ECG, however, would not have changed these patients' ED courses.


Subject(s)
Cardiovascular Diseases/diagnosis , Diagnosis, Computer-Assisted/standards , Electrocardiography/statistics & numerical data , Emergency Service, Hospital/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , California , Cardiology/standards , Cardiovascular Diseases/epidemiology , Diagnostic Errors/prevention & control , Female , Humans , Male , Middle Aged , Retrospective Studies , Risk Assessment , Triage/methods , Triage/standards , Young Adult
4.
J Emerg Med ; 63(3): 332-338, 2022 09.
Article in English | MEDLINE | ID: mdl-35400507

ABSTRACT

BACKGROUND: High rates of asymptomatic infections with COVID-19 have been reported. OBJECTIVE: We aimed to describe an asymptomatic COVID-19 testing protocol in a pediatric emergency department (ED). METHODS: This was a retrospective cohort study of pediatric patients (younger than 18 years) who were tested for COVID-19 via the asymptomatic testing protocol at a single urban pediatric ED between May 2020 and January 2021. This included all pediatric patients undergoing admission, urgent procedures, and psychiatric facility placement. The primary outcome was the percentage of positive COVID-19 tests. COVID-19 testing was performed via real-time polymerase chain reaction RNA assay testing. County-level COVID-19 data were used to estimate local daily COVID-19 cases/100,000 individuals (from all ages). Data were described with simple descriptive statistics. RESULTS: There were 1459 children tested for COVID-19 under the asymptomatic protocol. Mean ± standard deviation age was 8.2 ± 5.8 years. Two tests were inconclusive and 29 (2.0%; 95% confidence interval [CI] 1.3-2.8%) were positive. Of the 29 positive cases, 14 (48%; 95% CI 29-67%) had abnormal vital signs or signs and symptoms of COVID-19, on retrospective review. A total of 15 truly asymptomatic infections were identified. On the days that asymptomatic cases were identified, the lowest average daily community rate was 7.67 cases/100,000 individuals. CONCLUSIONS: Asymptomatic COVID-19 positivity rates in the pediatric ED were low when the average daily community rate was fewer than 7.5 cases/100,000 individuals. In the current pandemic, ED clinicians should assess for signs and symptoms of COVID-19, even when children present to the ED with unrelated chief symptoms.


Subject(s)
COVID-19 , Humans , Child , Child, Preschool , Adolescent , COVID-19/diagnosis , COVID-19 Testing , Asymptomatic Infections/epidemiology , SARS-CoV-2 , Retrospective Studies , Emergency Service, Hospital
5.
Pediatr Emerg Care ; 38(7): 326-331, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-26555312

ABSTRACT

OBJECTIVE: The objective of the study was to describe the epidemiology, cranial computed tomography (CT) findings, and clinical outcomes of children with blunt head trauma after television tip-over injuries. METHODS: We performed a secondary analysis of children younger than 18 years prospectively evaluated for blunt head trauma at 25 emergency departments (EDs) in the Pediatric Emergency Care Applied Research Network from June 2004 to September 2006. Children injured from falling televisions were included. Patients were excluded if injuries occurred more than 24 hours before ED evaluation or if neuroimaging was obtained before evaluation. Data collected included age, race, sex, cranial CT findings, and clinical outcomes. Clinically important traumatic brain injuries (ciTBIs) were defined as death from TBI, neurosurgery, intubation for more than 24 hours for the TBI, or hospital admission of 2 nights or more for the head injury, in association with TBI on CT. RESULTS: A total of 43,904 children were enrolled into the primary study and 218 (0.5%; 95% confidence interval [CI], 0.4% to 0.6%) were struck by falling televisions. The median (interquartile range) age of the 218 patients was 3.1 (1.9-4.9) years. Seventy-five (34%) of the 218 underwent CT scanning. Ten (13.3%; 95% CI, 6.6% to 23.2%) of the 75 patients with an ED CT had traumatic findings on cranial CT scan. Six patients met the criteria for ciTBI. Three of these patients died. All 6 patients with ciTBIs were younger than 5 years. CONCLUSIONS: Television tip-overs may cause ciTBIs in children, including death, and the most severe injuries occur in children 5 years or younger. These injuries may be preventable by simple preventive measures such as anchoring television sets with straps.


Subject(s)
Brain Injuries, Traumatic , Emergency Medical Services , Head Injuries, Closed , Brain Injuries, Traumatic/diagnostic imaging , Brain Injuries, Traumatic/epidemiology , Brain Injuries, Traumatic/etiology , Child , Child, Preschool , Cohort Studies , Emergency Service, Hospital , Head Injuries, Closed/complications , Head Injuries, Closed/diagnostic imaging , Head Injuries, Closed/epidemiology , Humans , Infant , Prospective Studies , Television
6.
Proc Biol Sci ; 288(1965): 20212131, 2021 12 22.
Article in English | MEDLINE | ID: mdl-34905705

ABSTRACT

The exceptional fossil record of trilobites provides our best window on developmental processes in early euarthropods, but data on growth dynamics are limited. Here, we analyse post-embryonic axial growth in the Cambrian trilobite Estaingia bilobata from the Emu Bay Shale, South Australia. Using threshold models, we show that abrupt changes in growth trajectories of different body sections occurred in two phases, closely associated with the anamorphic/epimorphic and meraspid/holaspid transitions. These changes are similar to the progression to sexual maturity seen in certain extant euarthropods and suggest that the onset of maturity coincided with the commencement of the holaspid period. We also conduct hypothesis testing to reveal the likely controls of observed axial growth gradients and suggest that size may better explain growth patterns than moult stage. The two phases of allometric change in E. bilobata, as well as probable differing growth regulation in the earliest post-embryonic stages, suggest that observed body segmentation patterns in this trilobite were the result of a complex series of changing growth controls that characterized different ontogenetic intervals. This indicates that trilobite development is more complex than previously thought, even in early members of the clade.


Subject(s)
Arthropods , Animals , Arthropods/physiology , Biological Evolution , Fossils , Molting , Morphogenesis , South Australia
7.
Proc Biol Sci ; 288(1943): 20202075, 2021 01 27.
Article in English | MEDLINE | ID: mdl-33499790

ABSTRACT

Durophagy arose in the Cambrian and greatly influenced the diversification of biomineralized defensive structures throughout the Phanerozoic. Spinose gnathobases on protopodites of Cambrian euarthropod limbs are considered key innovations for shell-crushing, yet few studies have demonstrated their effectiveness with biomechanical models. Here we present finite-element analysis models of two Cambrian trilobites with prominent gnathobases-Redlichia rex and Olenoides serratus-and compare these to the protopodites of the Cambrian euarthropod Sidneyia inexpectans and the modern American horseshoe crab, Limulus polyphemus. Results show that L. polyphemus, S. inexpectans and R. rex have broadly similar microstrain patterns, reflecting effective durophagous abilities. Conversely, low microstrain values across the O. serratus protopodite suggest that the elongate gnathobasic spines transferred minimal strain, implying that this species was less well-adapted to masticate hard prey. These results confirm that Cambrian euarthropods with transversely elongate protopodites bearing short, robust gnathobasic spines were likely durophages. Comparatively, taxa with shorter protopodites armed with long spines, such as O. serratus, were more likely restricted to a soft food diet. The prevalence of Cambrian gnathobase-bearing euarthropods and their various feeding specializations may have accelerated the development of complex trophic relationships within early animal ecosystems, especially the 'arms race' between predators and biomineralized prey.


Subject(s)
Arthropods , Fossils , Animals , Biological Evolution , Ecosystem , Extremities/anatomy & histology , Mastication
8.
Magn Reson Med ; 86(1): 293-307, 2021 07.
Article in English | MEDLINE | ID: mdl-33615527

ABSTRACT

PURPOSE: Velocity selective arterial spin labeling (VS-ASL) is a promising approach for non-contrast perfusion imaging that provides robustness to vascular geometry and transit times; however, VS-ASL assumes spatially uniform tagging efficiency. This work presents a mapping approach to investigate VS-ASL relative tagging efficiency including the impact of local susceptibility effects on a BIR-8 preparation. METHODS: Numerical simulations of tagging efficiency were performed to evaluate sensitivity to regionally varying local susceptibility gradients and blood velocity. Tagging efficiency mapping was performed in susceptibility phantoms and healthy human subjects (N = 7) using a VS-ASL preparation module followed by a short, high spatial resolution 3D radial-based image acquisition. Tagging efficiency maps were compared to 4D-flow, B1 , and B0 maps acquired in the same imaging session for six of the seven subjects. RESULTS: Numerical simulations were found to predict reduced tagging efficiency with the combination of high blood velocity and local gradient fields. Phantom experiments corroborated numerical results. Relative efficiency mapping in normal volunteers showed unique efficiency patterns depending on individual subject anatomy and physiology. Uniform tagging efficiency was generally observed in vivo, but reduced efficiency was noted in regions of high blood velocity and local susceptibility gradients. CONCLUSION: We demonstrate an approach to map the relative tagging efficiency and show application of this methodology to a novel BIR-8 preparation recently proposed in the literature. We present results showing rapid flow in the presence of local susceptibility gradients can lead to complicated signal modulations in both tag and control images and reduced tagging efficiency.


Subject(s)
Arteries , Cerebrovascular Circulation , Humans , Imaging, Three-Dimensional , Magnetic Resonance Angiography , Spatial Analysis , Spin Labels
9.
Magn Reson Med ; 85(6): 3071-3084, 2021 06.
Article in English | MEDLINE | ID: mdl-33306217

ABSTRACT

PURPOSE: Current breast DCE-MRI strategies provide high sensitivity for cancer detection but are known to be insufficient in fully capturing rapidly changing contrast kinetics at high spatial resolution across both breasts. Advanced acquisition and reconstruction strategies aim to improve spatial and temporal resolution and increase specificity for disease characterization. In this work, we evaluate the spatial and temporal fidelity of a modified data-driven low-rank-based model (known as MOCCO, model consistency condition) compressed-sensing (CS) reconstruction compared to CS with temporal total variation with radial acquisition for high spatial-temporal breast DCE MRI. METHODS: Reconstruction performance was characterized using numerical simulations of a golden-angle stack-of-stars breast DCE-MRI acquisition at 5-second temporal resolution. Specifically, MOCCO was compared with CS total variation and conventional SENSE reconstructions. The temporal model for MOCCO was prelearned over the source data, whereas CS total variation was performed using a first-order temporal gradient sparsity transform. RESULTS: The MOCCO reconstruction was able to capture rapid lesion kinetics while providing high image quality across a range of optimal regularization values. It also recovered kinetics in small lesions (1.5 mm) in line-profile analysis and error images, whereas g-factor maps showed relatively low and constant values with no significant artifacts. The CS-TV method demonstrated either recovery of high spatial resolution with reduced temporal accuracy using large regularization values, or recovery of rapid lesion kinetics with reduced image quality using low regularization values. CONCLUSION: Simulations demonstrated that MOCCO with radial acquisition provides a robust imaging technique for improving temporal fidelity, while maintaining high spatial resolution and image quality in the setting of bilateral breast DCE MRI.


Subject(s)
Contrast Media , Image Interpretation, Computer-Assisted , Artifacts , Breast/diagnostic imaging , Magnetic Resonance Imaging
10.
Pediatr Crit Care Med ; 22(7): 616-628, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33689253

ABSTRACT

OBJECTIVES: To describe characteristics and outcomes of children with burn injury treated in U.S. PICUs. DESIGN: Retrospective study of admissions in the Virtual Pediatric Systems, LLC, database from 2009 to 2017. SETTING: One hundred and seventeen PICUs in the United States. PATIENTS: Patients less than 18 years old admitted with an active diagnosis of burn at admission. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 2,056 patients were included. They were predominantly male (62.6%) and less than 6 years old (66.7%). Cutaneous burns were recorded in 92.1% of patients, mouth/pharynx burns in 5.8%, inhalation injury in 5.1%, and larynx/trachea/lung burns in 4.5%. Among those with an etiology recorded (n = 861), scald was most common (38.6%), particularly in children less than 2 years old (67.8%). Fire/flame burns were most common (46.6%) in children greater than or equal to 2 years. Multiple organ failure was present in 26.2% of patients. Most patients (89%) were at facilities without American Burn Association pediatric verification. PICU mortality occurred in 4.5% of patients. On multivariable analysis using Pediatric Index of Mortality 2, greater than or equal to 30% total body surface area burned was significantly associated with mortality (odds ratio, 5.40; 95% CI, 2.16-13.51; p = 0.0003). When Pediatric Risk of Mortality III was used, greater than or equal to 30% total body surface area burned (odds ratio, 5.45; 95% CI, 1.95-15.26; p = 0.001) and inhalation injury (odds ratio, 5.39; 95% CI, 1.58-18.42; p = 0.007) were significantly associated with mortality. Among 366 survivors (18.6%) with Pediatric Cerebral Performance Category or Pediatric Overall Performance Category data, 190 (51.9%) had a greater than or equal to 1 point increase in Pediatric Cerebral Performance Category or Pediatric Overall Performance Category disability category and 80 (21.9%) had a new designation of moderate or severe disability, or persistent vegetative state. CONCLUSIONS: Burn-injured patients in U.S. PICUs have a substantial burden of organ failure, morbidity, and mortality. Coordination among specialized facilities may be particularly important in this population, especially for those with higher % total body surface area burned or inhalation injury.


Subject(s)
Burns , Adolescent , Body Surface Area , Burns/epidemiology , Child , Child, Preschool , Humans , Infant , Intensive Care Units, Pediatric , Male , Odds Ratio , Retrospective Studies , United States/epidemiology
11.
Geophys Res Lett ; 47(9): e2019GL083936, 2020 May 16.
Article in English | MEDLINE | ID: mdl-32713983

ABSTRACT

The impact of Mars's 2018 Global Dust Storm (GDS) on surface and near-surface air temperatures was investigated using an assimilation of Mars Climate Sounder observations. Rather than simply resulting in cooling everywhere from solar absorption (average surface radiative flux fell 26 W/m2), the globally averaged result was a 0.9-K surface warming. These diurnally averaged surface temperature changes had a novel, highly nonuniform spatial structure, with up to 16-K cooling/19-K warming. Net warming occurred in low thermal inertia regions, where rapid nighttime radiative cooling was compensated by increased longwave emission and scattering. This caused strong nightside warming, outweighing dayside cooling. The reduced surface-air temperature gradient closely coupled surface and air temperatures, even causing local dayside air warming. Results show good agreement with Mars Climate Sounder surface temperature retrievals. Comparisons with the 2001 GDS and free-running simulations show that GDS spatial structure is crucial in determining global surface temperature effects.

12.
Prehosp Emerg Care ; 24(1): 8-14, 2020.
Article in English | MEDLINE | ID: mdl-30895835

ABSTRACT

Objective: To evaluate the accuracy of emergency medical services (EMS) provider judgment for traumatic intracranial hemorrhage (tICH) in older patients following head trauma in the field. We also compared EMS provider judgment with other sets of field triage criteria. Methods: This was a prospective observational cohort study conducted with five EMS agencies and 11 hospitals in Northern California. Patients 55 years and older who experienced blunt head trauma were transported by EMS between August 1, 2015 and September 30, 2016, and received an initial cranial computed tomography (CT) imaging, were eligible. EMS providers were asked, "What is your suspicion for the patient having intracranial hemorrhage (bleeding in the brain)?" Responses were recorded as ordinal categories (<1%, 1-5%, >5-10%, >10-50%, or >50%) and the incidences of tICH were recorded for each category. The accuracy of EMS provider judgment was compared to other sets of triage criteria, including current field triage criteria, current field triage criteria plus multivariate logistical regression risk factors, and actual transport. Results: Among the 673 patients enrolled, 319 (47.0%) were male and the median age was 75 years (interquartile range 64-85). Seventy-six (11.3%) patients had tICH on initial cranial CT imaging. The increase in EMS provider judgment correlated with an increase in the incidence of tICH. EMS provider judgment had a sensitivity of 77.6% (95% CI 67.1-85.5%) and a specificity of 41.5% (37.7-45.5%) when using a threshold of 1% or higher suspicion for tICH. Current field triage criteria (Steps 1-3) was poorly sensitive (26.3%, 95% CI 17.7-37.2%) in identifying tICH and current field trial criteria plus multivariate logistical regression risk factors was sensitive (97.4%, 95% CI 90.9-99.3%) but poorly specific (12.9%, 95% CI 10.4-15.8%). Actual transport was comparable to EMS provider judgment (sensitivity 71.1%, 95% CI 60.0-80.0%; specificity 35.3%, 95% CI 31.6-38.3%). Conclusions: As EMS provider judgment for tICH increased, the incidence for tICH also increased. EMS provider judgment, using a threshold of 1% or higher suspicion for tICH, was more accurate than current field triage criteria, with and without additional risk factors included.


Subject(s)
Emergency Medical Services , Intracranial Hemorrhage, Traumatic/diagnosis , Intracranial Hemorrhage, Traumatic/epidemiology , Age Factors , Aged , Aged, 80 and over , California , Craniocerebral Trauma/complications , Female , Humans , Incidence , Male , Middle Aged , Prospective Studies , Risk Factors , Tomography, X-Ray Computed , Trauma Centers , Triage
13.
Magn Reson Med ; 82(1): 302-311, 2019 07.
Article in English | MEDLINE | ID: mdl-30859628

ABSTRACT

PURPOSE: To develop motion-robust, blood-suppressed diffusion-weighted imaging (DWI) of the liver with optimized diffusion encoding waveforms and evaluate the accuracy and reproducibility of quantitative apparent diffusion coefficient (ADC) measurements. METHODS: A novel approach for the design of diffusion weighting waveforms, termed M1-optimized diffusion imaging (MODI), is proposed. MODI includes an echo time-optimized motion-robust diffusion weighting gradient waveform design, with a small nonzero first-moment motion sensitivity (M1) value to enable blood signal suppression. Experiments were performed in eight healthy volunteers and five patient volunteers. In each case, DW images and ADC maps were compared between acquisitions using standard monopolar waveforms, motion moment-nulled (M1-nulled and M1-M2-nulled) waveforms, and the proposed MODI approach. RESULTS: Healthy volunteer experiments using MODI showed no significant ADC bias in the left lobe relative to the right lobe (p < .05) demonstrating robustness to cardiac motion, and no significant ADC bias with respect to monopolar-based ADC measured in the right lobe (p < .05), demonstrating blood signal suppression. In contrast, monopolar-based ADC showed significant bias in the left lobe relative to the right lobe (p < .01) due to its sensitivity to motion, and both M1-nulled and M1-M2-nulled-based ADC showed significant bias (p < .01) due to the lack of blood suppression. Preliminary patient results also suggest MODI may enable improved visualization and quantitative assessment of lesions throughout the entire liver. CONCLUSIONS: This novel method for diffusion gradient waveform design enables DWI of the liver with high robustness to motion and suppression of blood signals, overcoming the limitations of conventional monopolar waveforms and moment-nulled waveforms, respectively.


Subject(s)
Diffusion Magnetic Resonance Imaging/methods , Image Processing, Computer-Assisted/methods , Liver/diagnostic imaging , Algorithms , Humans , Liver Neoplasms/diagnostic imaging , Movement/physiology
14.
Magn Reson Med ; 81(2): 989-1003, 2019 02.
Article in English | MEDLINE | ID: mdl-30394568

ABSTRACT

PURPOSE: To present a novel Optimized Diffusion-weighting Gradient waveform Design (ODGD) method for the design of minimum echo time (TE), bulk motion-compensated, and concomitant gradient (CG)-nulling waveforms for diffusion MRI. METHODS: ODGD motion-compensated waveforms were designed for various moment-nullings Mn (n = 0, 1, 2), for a range of b-values, and spatial resolutions, both without (ODGD-Mn ) and with CG-nulling (ODGD-Mn -CG). Phantom and in-vivo (brain and liver) experiments were conducted with various ODGD waveforms to compare motion robustness, signal-to-noise ratio (SNR), and apparent diffusion coefficient (ADC) maps with state-of-the-art waveforms. RESULTS: ODGD-Mn and ODGD-Mn -CG waveforms reduced the TE of state-of-the-art waveforms. This TE reduction resulted in significantly higher SNR (P < 0.05) in both phantom and in-vivo experiments. ODGD-M1 improved the SNR of BIPOLAR (42.8 ± 5.3 vs. 32.9 ± 3.3) in the brain, and ODGD-M2 the SNR of motion-compensated (MOCO) and Convex Optimized Diffusion Encoding-M2 (CODE-M2 ) (12.3 ± 3.6 vs. 9.7 ± 2.9 and 10.2 ± 3.4, respectively) in the liver. Further, ODGD-M2 also showed excellent motion robustness in the liver. ODGD-Mn -CG waveforms reduced the CG-related dephasing effects of non CG-nulling waveforms in phantom and in-vivo experiments, resulting in accurate ADC maps. CONCLUSIONS: ODGD waveforms enable motion-robust diffusion MRI with reduced TEs, increased SNR, and reduced ADC bias compared to state-of-the-art waveforms in theoretical results, simulations, phantoms and in-vivo experiments.


Subject(s)
Diffusion Magnetic Resonance Imaging , Echo-Planar Imaging , Motion , Phantoms, Imaging , Acetone , Algorithms , Brain/diagnostic imaging , Diagnostic Tests, Routine , Humans , Image Processing, Computer-Assisted/methods , Liver/diagnostic imaging , Signal-To-Noise Ratio
15.
Crit Care Med ; 46(12): e1097-e1104, 2018 12.
Article in English | MEDLINE | ID: mdl-30234568

ABSTRACT

OBJECTIVES: Major trials examining storage age of blood transfused to critically ill patients administered relatively few blood transfusions. We sought to determine if the storage age of blood affects outcomes when very large amounts of blood are transfused. DESIGN: A secondary analysis of the multicenter randomized Transfusion Requirement in Burn Care Evaluation study which compared restrictive and liberal transfusion strategies. SETTING: Eighteen tertiary-care burn centers. PATIENTS: Transfusion Requirement in Burn Care Evaluation evaluated 345 adults with burns greater than or equal to 20% of the body surface area. We included only the 303 patients that received blood transfusions. INTERVENTIONS: The storage ages of all transfused red cell units were collected during Transfusion Requirement in Burn Care Evaluation. A priori measures of storage age were the the mean storage age of all transfused blood and the proportion of all transfused blood considered very old (stored ≥ 35 d). MEASUREMENTS AND MAIN RESULTS: The primary outcome was the severity of multiple organ dysfunction. Secondary outcomes included time to wound healing, the duration of mechanical ventilation, and in-hospital mortality. There were 6,786 red cell transfusions with a mean (± SD) storage age of 25.6 ± 10.2 days. Participants received a mean of 23.4 ± 31.2 blood transfusions (range, 1-219) and a mean of 5.3 ± 10.7 units of very old blood. Neither mean storage age nor proportion of very old blood had any influence on multiple organ dysfunction severity, time to wound healing, or mortality. Duration of ventilation was significantly predicted by both mean blood storage age and the proportion of very old blood, but this was of questionable clinical relevance given extreme variability in duration of ventilation (adjusted r ≤ 0.01). CONCLUSIONS: Despite massive blood transfusion, including very old blood, the duration of red cell storage did not influence outcome in burn patients. Provision of the oldest blood first by Blood Banks is rational, even for massive transfusion.


Subject(s)
Blood Preservation/statistics & numerical data , Blood Transfusion/statistics & numerical data , Burns/therapy , Critical Illness/therapy , Intensive Care Units/statistics & numerical data , Adult , Burns/mortality , Critical Illness/mortality , Female , Hospital Mortality , Humans , Male , Middle Aged , Organ Dysfunction Scores , Respiration, Artificial/statistics & numerical data , Tertiary Care Centers , Time Factors , Trauma Severity Indices , Wound Healing/physiology
16.
Magn Reson Med ; 80(2): 685-695, 2018 08.
Article in English | MEDLINE | ID: mdl-29322549

ABSTRACT

PURPOSE: The purpose of this work is to characterize the noise distribution of proton density fat fraction (PDFF) measured using chemical shift-encoded MRI, and to provide alternative strategies to reduce bias in PDFF estimation. THEORY: We derived the probability density function for PDFF estimated using chemical shift-encoded MRI, and found it to exhibit an asymmetric noise distribution that contributes to signal-to-noise-ratio dependent bias. METHODS: To study PDFF noise bias, we performed (at 1.5 T) numerical simulations, phantom acquisitions, and a retrospective in vivo experiment. In each experiment, we compared the performance of three statistics (mean, median, and maximum likelihood estimator) in estimating the PDFF in a region of interest. RESULTS: We demonstrated the presence of the asymmetric noise distribution in simulations, phantoms, and in vivo. In each experiment we demonstrated that both the median and proposed maximum likelihood estimator statistics outperformed the mean statistic in mitigating noise-related bias for low signal-to-noise-ratio acquisitions. CONCLUSIONS: Characterization of the noise distribution of PDFF estimated using chemical shift-encoded MRI enabled new strategies based on median and maximum likelihood estimator statistics to mitigate noise-related bias for accurate PDFF measurement from a region of interest. Such strategies are important for quantitative chemical shift-encoded MRI applications that typically operate in low signal-to-noise-ratio regimes. Magn Reson Med 80:685-695, 2018. © 2018 International Society for Magnetic Resonance in Medicine.


Subject(s)
Adipose Tissue/diagnostic imaging , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Algorithms , Computer Simulation , Fatty Liver/diagnostic imaging , Humans , Liver/diagnostic imaging , Phantoms, Imaging , Protons , Signal-To-Noise Ratio
17.
Ann Emerg Med ; 72(6): 679-690, 2018 12.
Article in English | MEDLINE | ID: mdl-30078658

ABSTRACT

STUDY OBJECTIVE: We assess the productivity, outcomes, and experiences of participants in the National Institutes of Health/National Heart, Lung, and Blood Institute-funded K12 institutional research training programs in emergency care research. METHODS: We used a mixed-methods study design to evaluate the 6 K12 programs, including 2 surveys, participant interviews, scholar publications, grant submissions, and funded grants. The training program lasted from July 1, 2011, through June 30, 2017. We tracked scholars for a minimum of 3 years and up to 5 years, beginning with date of entry into the program. We interviewed program participants by telephone using open-ended prompts. RESULTS: There were 94 participants, including 43 faculty scholars, 13 principal investigators, 30 non-principal investigator primary mentors, and 8 program administrators. The survey had a 74% overall response rate, including 95% of scholars. On entry to the program, scholars were aged a median of 37 years (interquartile range [IQR] 34 to 40 years), with 16 women (37%), and represented 11 disciplines. Of the 43 scholars, 40 (93%) submitted a career development award or research project grant during or after the program; 26 (60%) have secured independent funding as of August 1, 2017. Starting with date of entry into the program, the median time to grant submission was 19 months (IQR 11 to 27 months) and time to funding was 33 months (IQR 27 to 39 months). Cumulative median publications per scholar increased from 7 (IQR 4 to 15.5) at program entry to 21 (IQR 11 to 33.5) in the first post-K12 year. We conducted 57 semistructured interviews and identified 7 primary themes. CONCLUSION: This training program produced 43 interdisciplinary investigators in emergency care research, with demonstrated productivity in grant funding and publications.


Subject(s)
Emergency Medicine/education , National Institutes of Health (U.S.)/organization & administration , Adult , Age Distribution , Female , Humans , Male , Middle Aged , Program Evaluation , Surveys and Questionnaires , United States
18.
Prehosp Emerg Care ; 22(1): 58-83, 2018.
Article in English | MEDLINE | ID: mdl-28792281

ABSTRACT

BACKGROUND: Trauma is a major health burden and a time-dependent critical emergency condition among developing and developed countries. In Asia, trauma has become a rapidly expanding epidemic and has spread out to many underdeveloped and developing countries through rapid urbanization and industrialization. Most casualties of severe trauma, which results in significant mortality and disability are assessed and transported by prehospital providers including physicians, professional providers, and volunteer providers. Trauma registries have been developed in mostly developed countries and measure care quality, process, and outcomes. In general, existing registries tend to focus on inhospital care rather than prehospital care. METHODS: The Pan-Asia Trauma Outcomes Study (PATOS) was proposed in 2013 and initiated in November, 2015 in order to establish a collaborative standardized study to measure the capabilities, processes and outcomes of trauma care throughout Asia. The PATOS is an international, multicenter, and observational research network to collect trauma cases transported by emergency medical services (EMS) providers. Data are collected from the participating hospital emergency departments in various countries in Asia which receive trauma patients from EMS. Data variables collected include 1) injury epidemiologic factors, 2) EMS factors, 3) emergency department care factors, 4) hospital care factors, and 5) trauma system factors. The authors expect to achieve a sample size of 67,230 cases over the next 2 years of data collection to analyze the association between potential risks and outcomes of trauma. CONCLUSION: The PATOS network is expected to provide comparison of the trauma EMS systems and to benchmark best practice with participating communities.


Subject(s)
Emergency Medical Services/statistics & numerical data , Emergency Service, Hospital/statistics & numerical data , Registries/statistics & numerical data , Wounds and Injuries/epidemiology , Asia/epidemiology , Data Collection/methods , Delivery of Health Care/statistics & numerical data , Female , Humans , Male , Quality of Health Care , Survival Rate , Wounds and Injuries/therapy
19.
Ann Surg ; 266(4): 595-602, 2017 10.
Article in English | MEDLINE | ID: mdl-28697050

ABSTRACT

OBJECTIVE: Our objective was to compare outcomes of a restrictive to a liberal red cell transfusion strategy in 20% or more total body surface area (TBSA) burn patients. We hypothesized that the restrictive group would have less blood stream infection (BSI), organ dysfunction, and mortality. BACKGROUND: Patients with major burns have major (>1 blood volume) transfusion requirements. Studies suggest that a restrictive blood transfusion strategy is equivalent to a liberal strategy. However, major burn injury is precluded from these studies. The optimal transfusion strategy in major burn injury is thus needed but remains unknown. METHODS: This prospective randomized multicenter trial block randomized patients to a restrictive (hemoglobin 7-8 g/dL) or liberal (hemoglobin 10-11 g/dL) transfusion strategy throughout hospitalization. Data collected included demographics, infections, transfusions, and outcomes. RESULTS: Eighteen burn centers enrolled 345 patients with 20% or more TBSA burn similar in age, TBSA burn, and inhalation injury. A total of 7054 units blood were transfused. The restrictive group received fewer blood transfusions: mean 20.3 ±â€Š32.7 units, median = 8 (interquartile range: 3, 24) versus mean 31.8 ±â€Š44.3 units, median = 16 (interquartile range: 7, 40) in the liberal group (P < 0.0001, Wilcoxon rank sum). BSI incidence, organ dysfunction, ventilator days, and time to wound healing (P > 0.05) were similar. In addition, there was no 30-day mortality difference: 9.5% restrictive versus 8.5% liberal (P = 0.892, χ test). CONCLUSIONS: A restrictive transfusion strategy halved blood product utilization. Although the restrictive strategy did not decrease BSI, mortality, or organ dysfunction in major burn injury, these outcomes were no worse than the liberal strategy (Clinicaltrials.gov identifier NCT01079247).


Subject(s)
Blood Transfusion/methods , Burns/therapy , Adolescent , Adult , Bacteremia/epidemiology , Burns/complications , Burns/mortality , Humans , Incidence , Infections/epidemiology , Length of Stay , Middle Aged , Multiple Organ Failure/epidemiology , Prospective Studies , Respiration, Artificial , Time Factors , Treatment Outcome , Wound Healing , Young Adult
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