bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amiodarone Attenuates Fluoride‐induced Hyperkalemia in Vitro
Authors: Su Mark , Chu Jason , Howland Mary Ann , Nelson Lewis S. , Hoffman Robert S. 
Published: February 2003

AbstractPoisoning by hydrofluoric acid or fluoride salts results in hypocalcemia, hypomagnesemia, and hyperkalemia with subsequent cardiac dysrhythmias. In previous studies, quinidine attenuated fluoride‐induced hyperkalemia in vitro, and enhanced survival in animals. Like quinidine, amiodarone is a potassium channel blocker, although amiodarone is more familiar to clinicians due to its recent inclusion in advanced cardiac life support (ACLS) protocols. Objectives: This in‐vitro study of human erythrocytes was designed to determine whether amiodarone could attenuate fluoride‐induced hyperkalemia. Methods: Six healthy volunteers each donated 60 mL of blood on three occasions. Each specimen was divided into 12 tubes, incubated at 37°C, and oxygenated with room air. An aqueous sodium fluoride (F−) solution was added to tubes 1–9. Incremental amounts of quinidine were added to tubes 1–4 (Q1–Q4) to attain calculated concentrations of 0.73 μg/mL, 1.45 μg/mL, 2.9 μg/mL, and 5.8 μg/mL, respectively. Incremental amounts of amiodarone were added to tubes 5–8 (A1–A4) to attain calculated concentrations of 0.38 μg/mL, 0.75 μg/mL, 1.5 μg/mL, and 3.0 μg/mL, respectively. Tubes 9–12 were controls for each of F−, amiodarone, quinidine alone, and no additive, respectively. Extracellular potassium concentration ([K+]) was followed, and an objective endpoint was defined as the rise in potassium concentration at 6 hours. Results: Fluoride produced a significant change in [K+] by 6 hours in all samples. Quinidine produced a J‐shaped curve in its ability to attenuate the rise in [K+], with only one concentration, Q3, demonstrating significance versus tube 9 (control). Amiodarone also demonstrated a J‐shaped dose–response effect, with statistical significance at A1, A2, and A3 versus tube 9 (control). There was no significant difference among the effective concentrations (Q3, A1, A2, and A3) of both drugs. Conclusions: In this in‐vitro model using human blood, amiodarone and quinidine both attenuated F−‐induced hyperkalemia. Further study is indicated to determine whether amiodarone enhances survival in F−‐poisoned animals.
Beta‐Human Chorionic Gonadotropin Levels and the Likelihood of Ectopic Pregnancy in Emergency Department Patients with Abdominal Pain or Vaginal Bleeding
Authors: Kohn Michael A. , Kerr Kristi , Malkevich David , O'Neil Nelda , Kerr M. James , Kaplan Beth C. 
Published: February 2003

AbstractStrategies for diagnosing ectopic pregnancy that defer endovaginal ultrasound in women with suggestive symptoms and serum beta‐human chorionic gonadotropin (β‐hCG) levels less than 1,500 mIU/mL ignore the increased risk of ectopic pregnancy in these patients. Objective: To quantify this increased risk by establishing and comparing the β‐hCG distributions of symptomatic women with ectopic pregnancies, abnormal intrauterine pregnancies, and normal intrauterine pregnancies. Methods: The authors reviewed the records of a cohort of women who visited an urban emergency department (ED) during a 34‐month period with abdominal pain or vaginal bleeding and non‐zero quantitative β‐hCG levels. Explicit criteria were used to determine whether the pregnancy ultimately turned out to be intrauterine and normal, intrauterine and abnormal, or ectopic. Probability distributions were compared using frequency distributions, receiver operating characteristic (ROC) curves, and likelihood ratios. Results: Of 730 ED patients included in the analysis, 96 (13%) had ectopic pregnancies, 253 (35%) had abnormal intrauterine pregnancies, and 381 (52%) had normal intrauterine pregnancies. The β‐hCG distributions of patients with ectopic pregnancies and abnormal intrauterine pregnancies were similar and much lower than the β‐hCG distribution of patients with normal intrauterine pregnancies. A β‐hCG level less than 1,500 mIU/mL more than doubled the odds of ectopic pregnancy (likelihood ratio = 2.24). Of the 158 patients with β‐hCG below 1,500 mIU/mL, 40 (25%; 95% confidence interval [CI] = 19% to 32%) had ectopic pregnancies, and only 25 (16%; CI = 11% to 22%) had normal intrauterine pregnancies. Conclusions: In women with pain or bleeding and serum β‐hCG levels less than 1,500 mIU/mL, the risk of ectopic pregnancy is substantially increased, while the likelihood of normal intrauterine pregnancy is low.
The Effect of Hospital Occupancy on Emergency Department Length of Stay and Patient Disposition
Authors: Forster Alan J. , Stiell Ian , Wells George , Lee Alexander J. , Van Walraven Carl 
Published: February 2003

AbstractEmergency department (ED) overcrowding is a common problem. Despite a widespread belief that low hospital bed availability contributes to ED overcrowding, there are few data demonstrating this effect. Objectives: To identify the effect of hospital occupancy on ED length of stay for admitted patients and patient disposition. Methods: This was an observational study design using administrative data at a 500‐bed acute care teaching hospital. All patients presenting to the ED between April 1993 and June 1999 were included in the study. The predictor variable was daily hospital occupancy. Outcome measures included daily ED length of stay for admitted patients, daily consultation rate, and daily admission rate. The models controlled for the average daily age of ED patients and the average daily “arrival density” index, which adjusts for patient volume and clustering of patient arrivals. Results: The average hospital occupancy was 89.7%. On average 155 patients visited the ED daily; 21% were referred to hospital physicians and 19% were admitted. The median ED length of stay for admitted patients was 5 hours 54 minutes (interquartile range 5 hr 12 min to 6 hr 42 min). Daily ED length of stay for admitted patients increased 18 minutes (95% CI = 12 to 24) when there was an absolute increase in occupancy of 10%. The ED length of stay appeared to increase extensively when hospital occupancy exceeded a threshold of 90%. Consultation and admission rates were not influenced by hospital occupancy. Conclusions: Increased hospital occupancy is strongly associated with ED length of stay for admitted patients. Increasing hospital bed availability might reduce ED overcrowding.
Etomidate for Rapid‐sequence Intubation in Young Children: Hemodynamic Effects and Adverse Events
Authors: Guldner Gregory , Schultz Jason , Sexton Perry , Fortner Corwyn , Richmond Mark 
Published: February 2003

Abstract Objectives: Physicians commonly use etomidate for adult rapid‐sequence intubation (RSI), but the manufacturer does not recommend its use for children under 10 years of age due to a lack of data. The authors present their experience with etomidate for pediatric RSI in order to further develop its risk–benefit profile in this age group. Methods: Trained abstractors reviewed the medical records for all children under 10 years old who received etomidate for RSI between July 1996 and April 2001. Results: 105 children, with an average age of 3 (±2.9) years, received a median dose of 0.32 (±0.12) mg/kg of etomidate. The systolic blood pressure increased an average of 4 mm Hg (95% CI =−3.3 to 9.2); the diastolic blood pressure increased 7 mm Hg (95% CI =−3.1 to 11) within 10 minutes of receiving etomidate. The heart rate increased an average of 10 beats/min (95% CI = 4.0 to 17.4). Complications included three patients who vomited within 10 minutes of etomidate administration. There were no cases of documented myoclonus, status epilepticus, or new‐onset seizures. Thirty‐eight patients received corticosteroids during the hospital course, none for suspected adrenal insufficiency. Three patients died, all from severe brain injury. Conclusions: In children less than 10 years old, etomidate seems to produce minimal hemodynamic changes, and appears to have a low risk of clinically important adrenal insufficiency, myoclonus, and status epilepticus. The association between etomidate and emesis (observed in less than 3% of enrolled patients) remains unclear. For clinical situations in which minimal blood pressure changes during RSI are critical, etomidate appears to have a favorable risk–benefit profile for children under 10 years old.
Ventilatory Response during Dissociative Sedation in Children—A Pilot Study
Authors: Kim Grace , Green Steven M. , Denmark T. Kent , Krauss Baruch 
Published: February 2003

Abstract Objectives: It is unclear whether ketamine induces subclinical respiratory depression when administered in dissociative doses intravenously (IV). The authors report a pilot study of capnography in emergency department (ED) pediatric patients receiving ketamine alone for procedural sedation, and describe serial measures of ventilatory response [end‐tidal carbon dioxide (EtCO2), respiratory rate, pulse oximetry]. Methods: The authors performed continuous capnography on a convenience sample of 20 ED pediatric patients who received ketamine 1.5 mg/kg IV for procedural sedation. Results: Continuous EtCO2 and pulse oximetry remained essentially unchanged following ketamine injection, and no EtCO2 levels > 47 mm Hg were noted at any point throughout sedation. Conclusions: No hypoventilation was observed in 20 ED pediatric patients receiving ketamine 1.5 mg/kg administered IV over 1 minute. The authors found no evidence of respiratory depressant properties for this dissociative agent.
Can Emergency Department Triage Nurses Appropriately Utilize the Ottawa Knee Rules to Order Radiographs?—An Implementation Trial
Authors: Kec Robert M. , Richman Peter B. , Szucs Paul A. , Mandell Mark , Eskin Barnet 
Published: February 2003

Abstract Objective: To determine whether triage nurses can successfully interpret the Ottawa Knee Rule (OKR) and order knee radiographs according to the OKR. Methods: This was a prospective implementation trial of a clinical decision rule, set in a suburban, community emergency department (ED), evaluating a convenience sample of ED patients aged > 17 years with acute knee injuries. Patients were excluded for altered mental status, distracting injuries, and knee lacerations. Triage nurses and attending emergency physicians (EPs) were trained in appropriate use of the OKR. The triage nurses evaluated eligible patients and radiographs were ordered according to their interpretation of the OKR. EPs who were initially blinded to the triage assessments also evaluated the patients. EPs could add an x‐ray order if, according to their assessment of the OKR, one was indicated and a radiograph had not been ordered by the nurse. Nurses and EPs recorded their blinded assessments on standardized data collection instruments. Kappa values were calculated to assess interobserver agreement (IOA) between nurses and EPs; sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated as appropriate. Results: One hundred three patients were enrolled; 53% were female; 10 fractures were identified (9.7%). The IOAs between the nurses and EPs for each of the criteria were moderate to almost perfect: age—0.94; fibular head tenderness—0.4; isolated patellar tenderness—0.68; inability to bend knee to 90 degrees—0.73; inability to bear weight—0.76. The IOA was moderate (0.52) for the overall interpretation of the OKR by nurses and EPs. Sensitivity of nurse interpretation of the OKR for fracture was 70%, specificity 33%, NPV 91%, PPV 10%. Sensitivity of EP interpretation of the OKR for fracture was 100%, specificity 25%, NPV 100%, PPV 13%. Conclusions: Triage nurses showed fair to good ability to appropriately apply the OKR to pre‐order knee radiographs.
Incidence of Traumatic Lumbar Puncture
Authors: Shah Kaushal H. , Richard Kathleen M. , Nicholas Sarah , Edlow Jonathan A. 
Published: February 2003

Abstract Objective: To determine the incidence of traumatic lumbar puncture (LP). Methods: A retrospective study was conducted at an urban, university tertiary care referral center with 50,000 annual emergency department (ED) visits. The study population included all patients who had cerebrospinal fluid (CSF) samples sent to the laboratory between August 15, 2000, and August 14, 2001. The numbers of red blood cells (RBCs) recorded in the first and last CSF tubes, the location where the LP was performed, and the discharge summary and the discharge diagnoses from the particular visit were obtained. All patients with intracranial pathology and CSF obtained via neurosurgical procedure or fluoroscopic guidance were excluded from the study group. Given no clear definition of traumatic LP in the literature, the incidence of traumatic LP was calculated using a cutoff of greater than 400 RBCs (visual threshold for bloody fluid) and 1,000 RBCs (arbitrary threshold selected by other authors) in CSF tube 1. Proportions were compared using chi‐square statistics. Results: Seven hundred eighty‐six CSF samples were recorded over one year. Twenty‐four samples were obtained from patients with intracranial pathology or were obtained via a neurosurgical procedure. Of the remaining 762 CSF samples in the study population, 119 (15.6%) were traumatic using a cutoff of 400 RBCs, and 80 (10.5%) were traumatic, using a cutoff of 1,000 RBCs in tube 1. Five hundred three LPs were done in the ED and 259 were attributed to all other locations in the hospital. Using a cutoff of 400 RBCs, the incidence of traumatic LP in the ED was 13.3%, compared with 20% in the rest of the hospital (p < 0.025). Similarly, using a cutoff of 1,000 RBCs, the incidence of traumatic LP in the ED was 8.9%, compared with 13.5% in the rest of the hospital (p = 0.1). The incidence of “champagne taps” (defined as zero RBCs in the first and last tubes) in the ED was 34.4%, compared with 24.3% in the rest of the hospital (p < 0.01). Conclusions: The incidence of traumatic lumbar puncture is approximately 15% using a cutoff of 400 RBCs and 10% using a cutoff of 1,000 RBCs. In this study, the rate of traumatic lumbar puncture was significantly less (with a cutoff of 400 RBCs) and the rate of champagne tap was significantly greater for LPs done in the ED compared with the rest of the hospital.
Emergency Medicine Leadership in Industry‐sponsored Clinical Trials
Authors: Newgard Craig D. , Kim Sunghye , Camargo Carlos A. 
Published: February 2003

AbstractObjective:To identify and characterize emergency medicine (EM) researchers who, since 1990, have served on a steering committee (SC) or as overall principal investigator (PI) of an industry‐sponsored, multicenter clinical trial involving a pharmaceutical or device.Methods:North American EM research directors (RDs) and other prominent EM investigators (for those hospitals without a RD) were identified from eight sources, including the Society for Academic Emergency Medicine RD Interest Group and the Multicenter Airway Research Collaboration (MARC) database. The identified investigators were sent a screening survey requesting information regarding industry‐sponsored clinical research at their site. The individual EM investigators identified by this screening survey were then interviewed by telephone (validation survey) to further explore their leadership experience in industry‐sponsored clinical trials.Results:Of 153 identified RDs and prominent EM researchers, 138 responded to the screening survey (90% response rate). Eighty‐five EM investigators reportedly had served on a SC or as overall PI for an industry‐sponsored clinical trial. Of these 85 North American EM investigators, 77 were available for a structured telephone interview (91% response rate). Although 41 (53%) of the investigators confirmed their leadership role, 36 (47%) had not served in either role. Among the 41 confirmed investigators, 19 (25%) had served as a SC member, 10 (13%) had served as overall PI, and 12 (16%) had experience in both roles. Individual responses provided suggestions for pursuing such leadership positions.Conclusions:These data suggest the opportunity to expand EM leadership in industry‐sponsored clinical trials and demonstrate the need for validation of reports obtained by a departmental research contact. The suggestions from EM researchers who have attained these leadership roles may provide strategies for investigators interested in pursuing these positions.
Predictors of Success in Emergency Medicine Ultrasound Education
Authors: Costantino Thomas G. , Satz Wayne A. , Stahmer Sarah A. , Dean Anthony J. 
Published: February 2003

Abstract Objectives: To compare emergency medicine resident performance on an ultrasound‐oriented, American Board of Emergency Medicine–styled written examination with the following variables in resident education: number of ultrasound scans performed, presence of a formal, structured ultrasound rotation, presence of a mandatory ultrasound rotation, number of hours of didactic ultrasound education, and percentage of ultrasound education taught by emergency physicians. Methods: This was a prospective cohort study involving 14 residency programs. A 60‐question multiple‐choice test was completed by individual residents and returned for scoring. Results: 262 residents completed the study. Average score was 39.1/60 ± 6.5 (65%). Scores improved as residency year increased (year 1: 36.6, year 2: 39.3, year 3: 42.6) (p < 0.005). Scores improved as number of scans performed increased from 34.3 (57%) for those residents who had performed 0–10 scans to 45.4 (76%) for those with >150 scans (p < 0.005). The presence of an ultrasound rotation at an emergency medicine residency program also produced a statistically significant increase in test score (OR 1.82; 95% CI = 1.29 to 2.55). Residents at programs spending the least time (6 to 15 hours) on didactic education throughout the residency predicted examination failure (OR 0.60; 95% CI = 0.39 to 0.93). Increasing the amount of resident ultrasound teaching by emergency physicians improved the score, but this did not reach significance (p = 0.357). Conclusions: Improved resident performance on an ultrasound written examination was associated with increasing resident year, number of scans performed, and the presence of an ultrasound rotation at the residency program. Increasing the number of didactic hours spent on ultrasound each year beyond 15 hours showed no improvement in resident performance.
Preliminary Evidence for a Sulphur Cycle in Movile Cave, Romania
Authors: Rohwerder T. , Sand W. , Lascu C. 
Published: February 2003

AbstractIn order to investigate the food chain and energy balance of the chemolithoautotrophically‐based ecosystem of the sulphur spring in Movile Cave as a model system for extraterrestrial life, a first sampling campaign was done. Microbial diversity and activity were analysed by MPN‐enumeration methods and microcalorimetry, respectively. In addition, a speciation of the inorganic sulphur compounds by HPLC and IC techniques was performed. Metabolic activities were predominantly connected with thick microbial mats floating on the water surface of the cave. These mats showed an aerobic heat evolution of about 1200 μW/g and contained about 500 μmol/g elemental sulphur. In contrast, other samples collected from cave water, sediment and rock exhibited only activities of maximal 40 to 60 μW/g and contained only up to 2.5 μmol/g elemental sulphur. As the main primary producers aerobic and facultatively anaerobic sulphur oxidisers were identified at high numbers, occasionally exceeding 107 CFU/g. Methylotrophic bacteria were present in all samples at up to 106 CFU/g, indicating the important role of C1 metabolism for the cave ecosystem. Although reduced sulphur species were biologically oxidised to sulphuric acid, the pH values of the samples ranged from 6.5 to 8.2 due to the high buffering capacity of the cave walls, which consisted mainly of limestone. Surprisingly, not only neutrophilic but also extremely acidophilic bacteria were detected. Sulphate reducers were present in both aerobic and anaerobic zones. The data presented suggest a close interdependence of sulphur oxidation and reduction as well as carbon dioxide and other C1 compound metabolism in the most biologically active zone of the cave ecosystem, i.e. the floating microbial mats.
Characterisation of Archaea in Soils by Polar Lipid Analysis
Authors: Gattinger A. , Günthner A. , Schloter M. , Munch J.C. 
Published: February 2003

AbstractWhile phospholipid fatty acid (PLFA) profiling is a well‐established method used for the determination of bacterial and eukaryotic organisms in soil ecology, phospholipid etherlipid (PLEL) analyses for the characterisation of Archaea is a rather new approach. Analyses of PLEL derived isoprenoid side chains by GC/MS provided a broad picture of the archaeal community in a mixed soil extract, as lipids previously identified in isolates belonging to the kingdoms Eury‐ and Crenarchaeota were covered. Furthermore, ether‐linked isoprenoid hydrocarbons, which have not been detected in archaeal isolates and monomethyl‐branched alkanes which have only been found in hyperthermophilic bacteria, were detected in these soil extracts. Monomethyl‐branched alkanes were the most dominant ones and accounted for 43.4% of the total identified ether‐linked hydrocarbons, followed by straight chain (unbranched) and isoprenoid hydrocarbons, which accounted for 34.6 and 15.5%, respectively.
Purification and Characterisation of the Enantiospecific Dioxygenases from Delftia acidovorans MC1 Initiating the Degradation of Phenoxypropionate and Phenoxyacetate Herbicides
Authors: Westendorf A. , Müller R. H. , Babel W. 
Published: February 2003

AbstractAfter cultivation on (R,S)‐2‐(2,4‐dichlorophenoxy)propionate, two α‐ketoglutarate‐dependent dioxygenases were isolated and purified from Delftia acidovorans MC1, catalysing the cleavage of the ether bond of various phenoxyalkanoate herbicides. One of these enzymes showed high specificity for the cleavage of the R‐enantiomer of substituted phenoxypropionate derivatives: the Km values were 55 μM and 30 μM, the kcat values 55 min–1 and 34 min–1 with (R)‐2‐(2,4‐dichlorophenoxy)propionate [(R)‐2,4‐DP] and (R)‐2‐(4‐chloro‐2‐methylphenoxy)propionate, respectively. The other enzyme predominantly utilised the S‐enantiomers with Km values of 49 μM and 22 μM, and kcat values of 50 min–1 and 46 min–1 with (S)‐2‐(2,4‐dichlorophenoxy)propionate [(S)‐2,4‐DP] and (S)‐2‐(4‐chloro‐2‐methylphenoxy)propionate, respectively. In addition, it cleaved phenoxyacetate herbicides (i.e. 2,4‐dichlorophenoxyacetate: Km = 123 μM, kcat = 36 min–1) with significant activity. As the second substrate, only α‐ketoglutarate served as an oxygen acceptor for both enzymes. The enzymes were characterised by excess substrate inhibition kinetics with apparent Ki values of 3 mM with (R)‐2,4‐DP and 1.5 mM with (S)‐2,4‐DP. The reaction was strictly dependent on the presence of Fe2+ and ascorbate; other divalent cations showed inhibitory effects to different extents. Activity was completely extinguished within 2 min in the presence of 100 μM diethylpyrocarbonate (DEPC).
Stabilization of Semiconducting Polymers with Silsesquioxane
Authors: Xiao S. , Nguyen M. , Gong X. , Cao Y. , Wu H. , Moses D. , Heeger A.J. 
Published: February 2003

AbstractPolyhedral oligomeric silsesquioxanes (POSS) anchored to poly(2‐methoxy‐5‐(2‐ethylhexyloxy)‐1.4‐phenylenevinylene) (MEH‐PPV) (MEH‐PPV–POSS), and to poly(9,9‐dihexylfluorenyl‐2,7‐diyl) (PFO) (PFO–POSS) were synthesized. Compared with the corresponding parent polymers, MEH‐PPV and PFO, MEH‐PPV–POSS and PFO–POSS have better thermal stability. MEH‐PPV–POSS and MEH‐PPV have identical absorption and photoluminescent (PL) spectra, both in solution and as thin films. They also have identical electroluminescent (EL) spectra. Devices made from MEH‐PPV–POSS exhibit higher brightness (1320 cd m–2 at 3.5 V) and higher external quantum efficiency (ηext = 2.2 % photons per electron) compared to MEH‐PPV (230 cd m–2 at 3.5 V and ηext = 1.5 % ph el–1). Compared with PFO in the same device configuration, PFO–POSS has improved blue EL emission and higher ηext.