Home About us Contact
|
Home About us Contact | ||
|
|
||
Time Interval (time + interval)
Kinds of Time Interval Selected AbstractsThe Influence of Time Interval between Bleaching and Enamel BondingJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 2 2007Jéfferson Da Silva Machado dds ABSTRACT Objectives:, The purpose of this study was to investigate the penetration of a conventional adhesive material into enamel bleached with 16% carbamide peroxide and 38% hydrogen peroxide using optical light microscopy. Methods:, Extracted human teeth were randomly divided into eight experimental groups with six specimens each, according to the bleaching material and time interval after bleaching and before the bonding procedure. Groups were designated as follows: control group, restorations in unbleached teeth; restorations performed immediately after bleaching; restorations performed 7 days after bleaching; restorations performed 14 days after bleaching; and restorations performed 30 days after bleaching. The length of resin tags was measured with an Axiophot photomicroscope at 400× magnification for the calculation of the proportion of tags of study groups compared to the respective control groups. Analysis of variance was applied for comparison between groups; data were transformed into arcsine (p < 0.05). Results:, The specimens of experimental groups, in which restorations were performed 7, 14, and 30 days after bleaching, showed better penetration of adhesive material into enamel than specimens restored immediately after bleaching. There was no statistically significant difference between the bleaching materials employed or in the interaction between bleaching agent and time interval. Conclusions:, This suggests that a time interval of at least 7 days should be allowed between enamel bleaching and placement of adhesive bonding agents for accomplishment of composite resin restorations. CLINICAL SIGNIFICANCE Establishment of adequate time after bleaching is fundamental to allow the normal penetration of a one-bottle conventional adhesive onto the enamel surface. [source] Decreasing the Sampling Time Interval in Radioactive Particle TrackingTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2003Navid Mostoufi Abstract The study of the movement of solids in multiphase reactors using radioactive particle tracking is currently limited to fairly modest particle velocities because of count-rate limitations of the detection system. In this work, this restriction was overcome by increasing the activity of the radioactive tracer, by decreasing the sampling time interval and by modifying the particle tracking software to recognize which detectors were saturated and to use only the data from the remaining unsaturated detectors. Higher tracer activity resulted in lower standard deviation of the calculated tracer coordinates. L'étude du mouvement des solides par traçage avec des particules radioactives dans un réacteur polyphasique est actuellement limitée à des vitesses de particules relativement modestes à cause des limites de comptage du système de détection. Dans ce travail, on contourne cette restriction en accroissant l'activité du traceur radioactif, en diminuant l'intervalle de temps d'échantillonnage et en modifiant le logiciel de traçage des particules de façon à reconnaître les détecteurs qui sont saturés et à utiliser uniquement les données venant des détecteurs non saturés restants. Une plus grande activité du traceur donne un écart type plus petit pour les coordonnées de traceur calculées. [source] Hemodynamic Correlates of the Third Heart Sound and Systolic Time IntervalsCONGESTIVE HEART FAILURE, Issue 2006Sanjiv J. Shah MD Bedside diagnostic tools remain important in the care of patients with heart failure. Over the past two centuries, cardiac auscultation and phonocardiography have been essential in understanding cardiac pathophysiology and caring for patients with heart disease. Diastolic heart sounds (S3 and S4) and systolic time intervals have been particularly useful in this regard. Unfortunately, auscultation skills have declined considerably, and systolic time intervals have traditionally required carotid pulse tracings. Newer technology allows the automated detection of heart sounds and measurement of systolic time intervals in a simple, inexpensive, noninvasive system. Using the newer system, the authors present data on the hemodynamic correlates of the S3 and abnormal systolic time intervals. These data serve as the foundation for using the system to better understand the test characteristics and pathophysiology of the S3 and systolic time intervals, and help to define their use in improving the bedside diagnosis and management of patients with heart failure. [source] Performance of Phonoelectrocardiographic Left Ventricular Systolic Time Intervals and B-Type Natriuretic Peptide Levels in the Diagnosis of Left Ventricular DysfunctionANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2007Brian Moyers M.D. Background: Systolic time intervals measured by echocardiography and carotid artery tracings are validated methods of assessing left ventricular function. However, the clinical utility of phonoelectrocardiographic systolic time intervals for predicting heart failure using newer technology has not been evaluated. Methods: We enrolled 100 adult patients undergoing left heart catheterization. Participants underwent computerized phonoelectrocardiographic analysis, left ventricular end-diastolic pressure (LVEDP) measurement, transthoracic echocardiographic measurement of left ventricular ejection fraction (LVEF), and B-type natriuretic peptide (BNP) testing. The heart rate-adjusted systolic time intervals included the time from the Q wave onset to peak S1 (electromechanical activation time, EMAT), Q wave onset to peak S2 (electromechanical systole, Q-S2), and peak S1 to peak S2 (left ventricular systolic time, LVST). Left ventricular dysfunction was defined as the presence of both LVEDP >15 mmHg and LVEF <50%. Results: EMAT (r =,0.51; P < 0.0001), EMAT/LVST (r =,0.41; P = 0.0001), and Q-S2 (r =,0.39; P = 0.0003) correlated with LVEF, but not with LVEDP. An abnormal EMAT ,15 (odds ratio 1.38, P < 0.0001) and EMAT/LVST ,0.40 (OR 1.13, P = 0.002) were associated with left ventricular dysfunction. EMAT ,15 had 44% sensitivity, 94% specificity, and a 7.0 likelihood ratio for left ventricular dysfunction, while EMAT/LVST ,0.40 had 55% sensitivity, 95% specificity, and a 11.7 likelihood ratio. In patients with an intermediate BNP (100,500 pg/mL), the likelihood ratio increased from 1.1 using the BNP result alone to 11.0 when adding a positive EMAT test for predicting left ventricular dysfunction. Conclusions: Phonoelectrocardiographic measures of systolic time intervals are insensitive but highly specific tests for detecting abnormalities in objective markers of left ventricular function. EMAT and EMAT/LVST provide diagnostic information independent of BNP for detecting patients with left ventricular dysfunction. [source] Sequential Analysis of Pretreatment Delays In Stroke ThrombolysisACADEMIC EMERGENCY MEDICINE, Issue 9 2010Tuukka Puolakka BM ACADEMIC EMERGENCY MEDICINE 2010; 17:965,969 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, The aim was to determine if an intensive restructuring of the approach to acute stroke improved time to thrombolysis over a 3-year study period and to determine whether delay modifications correlated with increased thrombolytic intervention or functional outcome. Methods:, The study examined the pretreatment process to define specific time intervals (delays) of interest in the acute management of 289 consecutive ischemic stroke patients who were transported by the emergency medical services (EMS) and received intravenous (IV) thrombolytic therapy in the emergency department (ED) of Helsinki University Central Hospital. Time interval changes of the 3-year period and use of thrombolytics was measured. Functional outcome, measured with the modified Rankin Scale (mRS) at 3 months, was assessed with multivariable statistical analysis. Results:, During implementation of the restructuring program from 2003 to 2005, the median total time delay from symptom onset to drug administration dropped from 149 to 112 minutes (p < 0.0001). Prehospital delays did not change significantly during the study period. The median delay in calling an ambulance remained at 13 minutes, and the total median prehospital delay stayed at 71 minutes. In-hospital delays decreased from 67 to 34 minutes (p < 0.0001). The median call delay was 25 minutes in patients with mild symptoms (National Institute of Health Stroke Scale [NIHSS] score < 7) and 8 minutes with severe symptoms (NIHSS > 15). In the multivariate model, stroke severity (odds ratio [OR] = 0.83, 95% confidence interval [CI] = 0.78 to 0.88, p < 0.0001), age (OR = 0.57, 95% CI = 0.42 to 0.77, p < 0.0001), and in-hospital delay (OR = 0.47, 95% CI = 0.22 to 0.97, p = 0.04) were suggesting a good outcome. Conclusions:, Restructuring of the teamwork between the EMS personnel and the reorganized ED significantly reduced in-hospital, but not prehospital, delays. The present data suggest that a decreased in-hospital delay improves the accessibility of the benefits of thrombolysis. [source] An Algorithmic Framework for Specifying the Semantics of Discourse RelationsCOMPUTATIONAL INTELLIGENCE, Issue 4 2000Alistair Knott In this paper, a new framework is proposed for defining the semantics of discourse relations and for defining the semantics of the utterances that relations link together. The proposal is to define relations in terms of the operation of an algorithm simulating the mental state of an agent interacting with the world. The algorithm interleaves perception, theorem proving, and action: The denotation of a complex utterance containing a relation between two simpler utterances is taken to be the description of the operation of the algorithm during the time interval identified by their Reichenbachian reference times. This proposal is presented in detail for two discourse relations. Its potential application in the treatment of mood, tense, aspect, and dialogue structure is also discussed in very general terms. [source] Real-Time OD Estimation Using Automatic Vehicle Identification and Traffic Count DataCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2002Michael P. Dixon A key input to many advanced traffic management operations strategies are origin,destination (OD) matricies. In order to examine the possibility of estimating OD matricies in real-time, two constrained OD estimators, based on generalized least squares and Kalman filtering, were developed and tested. A one-at-a-time processing method was introduced to provide an efficient organized framework for incorporating observations from multiple data sources in real-time. The estimators were tested under different conditions based on the type of prior OD information available, the type of assignment available, and the type of link volume model used. The performance of the Kalman filter estimators also was compared to that of the generalized least squares estimator to provide insight regarding their performance characteristics relative to one another for given scenarios. Automatic vehicle identification (AVI) tag counts were used so that observed and estimated OD parameters could be compared. While the approach was motivated using AVI data, the methodology can be generalized to any situation where traffic counts are available and origin volumes can be estimated reliably. The primary means by which AVI data was utilized was through the incorporation of prior observed OD information as measurements, the inclusion of a deterministic link volume component that makes use of OD data extracted from the latest time interval from which all trips have been completed, and through the use of link choice proportions estimated based on link travel time data. It was found that utilizing prior observed OD data along with link counts improves estimator accuracy relative to OD estimation based exclusively on link counts. [source] Cardiac function during mild hypothermia in pigs: increased inotropy at the expense of diastolic dysfunctionACTA PHYSIOLOGICA, Issue 1 2010H. Post Abstract Aim:, The induction of mild hypothermia (MH; 33 °C) has become the guideline therapy to attenuate hypoxic brain injury after out-of-hospital cardiopulmonary resuscitation. While MH exerts a positive inotropic effect in vitro, MH reduces cardiac output in vivo and is thus discussed critically when severe cardiac dysfunction is present in patients. We thus assessed the effect of MH on the function of the normal heart in an in vivo model closely mimicking the clinical setting. Methods:, Ten anaesthetized, female human-sized pigs were acutely catheterized for measurement of pressure,volume loops (conductance catheter), cardiac output (Swan-Ganz catheter) and for vena cava inferior occlusion. Controlled MH (from 37 to 33 °C) was induced by a vena cava inferior cooling catheter. Results:, With MH, heart rate (HR) and whole body oxygen consumption decreased, while lactate levels remained normal. Cardiac output, left ventricular (LV) volumes, peak systolic and end-diastolic pressure and dP/dtmax did not change significantly. Changes in dP/dtmin and the time constant of isovolumetric relaxation demonstrated impaired active relaxation. In addition, MH prolonged the systolic and shortened the diastolic time interval. Pressure,volume analysis revealed increased end-systolic and end-diastolic stiffness, indicating positive inotropy and reduced end-diastolic distensibility. Positive inotropy was preserved during pacing, while LV end-diastolic pressure increased and diastolic filling was substantially impaired due to delayed LV relaxation. Conclusion:, MH negatively affects diastolic function, which, however, is compensated for by decreased spontaneous HR. Positive inotropy and a decrease in whole body oxygen consumption warrant further studies addressing the potential benefit of MH on the acutely failing heart. [source] An Ecological and Economic Assessment of the Nontimber Forest Product Gaharu Wood in Gunung Palung National Park, West Kalimantan, IndonesiaCONSERVATION BIOLOGY, Issue 6 2001Gary D. Paoli We studied the demographic effect and economic returns of harvesting aromatic gaharu wood from fungus-infected trees of Aquilaria malaccensis Lam. at Gunung Palung National Park, Indonesia, to evaluate the management potential of gaharu wood. Aquilaria malaccensis trees openface> 20 cm in diameter occurred at low preharvest densities (0.16,0.32 ha) but were distributed across five of six forest types surveyed. During a recent harvest, 75% of trees were felled, with harvest intensities ranging from 50% to 100% among forest types. Overall, 50% of trees contained gaharu wood, but trees at higher elevations contained gaharu wood more frequently ( 73%) than trees at lower elevation (27%). The mean density of regeneration ( juveniles> 15 cm in height) near adult trees (3,7 m away) was 0.2/m2, 200 times greater than at random in the forest (10/ha), but long-term data on growth and survivorship are needed to determine whether regeneration is sufficient for population recovery. Gaharu wood extraction from Gunung Palung was very profitable for collectors, generating an estimated gross financial return per day of US $8.80, triple the mean village wage. Yet, the estimated sustainable harvest of gaharu wood at natural tree densities generates a mean net present value of only $10.83/ha, much lower than that of commercial timber harvesting, the dominant forest use in Kalimantan. Returns per unit area could be improved substantially, however, by implementing known silvicultural methods to increase tree densities, increase the proportion of trees that produce gaharu wood, and shorten the time interval between successive harvests. The economic potential of gaharu wood is unusual among nontimber forest products and justifies experimental trials to develop small-scale cultivation methods. Resumen: Datos ecológicos y económicos son esenciales para la identificación de productos forestales no maderables tropicales con potencial para la extracción sostenible y rentable en un sistema bajo manejo. Estudiamos el efecto demográfico y los beneficios económicos de la cosecha de la madera aromática gaharu de árboles de Aquilaria malaccenis Lam infectados por hongos en el Parque Nacional Gunung Palung Indonesia para evaluar el potencial de manejo de la madera. Arboles de Aquilaria malaccenis> 20 cm de diámetro ocurrieron en bajas densidades precosecha (0.16,0.32 ha,1) pero se distribuyeron en cinco de los seis tipos de bosque muestreados. Durante una cosecha reciente, 75% de los árboles fueron cortados, con intensidades de cosecha entre 50 y 100% en los tipos de bosque. En conjunto, 50% de los árboles contenían madera gaharu, pero árboles de elevaciones mayores contenían madera gaharu más frecuentemente ( 73%) que árboles de elevaciones menores (27%). La densidad promedio de regeneración ( juveniles> 15 cm de altura) cerca de árboles adultos (de 3 a 7 m de distancia) fue de 0.2 m,2, 200 veces mayor que en el bosque (10 ha,1), pero se requieren datos a largo plazo sobre el crecimiento y la supervivencia para determinar si la regeneración es suficiente para la recuperación de la población. La extracción de madera gaharu de Gunung Palung fue muy redituable, generando un rendimiento financiero bruto estimado en US $8.80 diarios, el triple del salario promedio en la zona. Sin embargo, la cosecha sostenible estimada de madera gaharu en densidades naturales de árboles genera un valor presente neto de sólo $10.83 ha,1, mucho menor que el de la cosecha comercial de madera, uso dominante del bosque en Kalimantan. Sin embargo, los rendimientos por unidad de área podrían mejorar sustancialmente mediante la instrumentación de métodos silviculturales para incrementar la densidad de árboles, incrementar la proporción de árboles que producen madera gaharu y reducir el intervalo de tiempo entre cosechas sucesivas. El potencial económico de la madera gaharu es poco usual entre los productos forestales no maderables y justifica la experimentación para desarrollar métodos de cultivo en pequeña escala. [source] Relevance of Cosmeceuticals to the Dermatologic SurgeonDERMATOLOGIC SURGERY, Issue 2005Harold J. Brody MD Background. The dermatologic surgeon is the dermatologist with special expertise in the surgical care of the health and beauty of the skin. Objectives, Methods, Results. There is no better arena for the use of topical regimens to preserve skin quality than in the time interval devoted to before and after care with respect to surgical procedures. Conclusion. Many of these regimens can be tailor devised with topical drugs and cosmeceuticals together in proper balance in the patient's best interest for affordable health care. HAROLD J. BRODY, MD, HAS INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source] Repeated exposures to gustatory stimuli produce habituation or positive contrast effects in perinatal ratsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2004G. Andrew Mickley Abstract Adult rats exhibit a decrease in consummatory responses following repeated presentations of a taste (habituation) and an increase in consummatory responses if they experience an upward shift in the magnitude or intensity of a gustatory stimulus (e.g., sucrose or saccharin). These responses do not represent a direct sensorimotor reaction to a gustatory cue, but rather reflect a change in responding based on the memory of a previous taste. Here, we sought to determine if fetal rats could (like adults) adjust their orofacial motor responses based on a memory of recent gustatory experience. Embryonic Day 18 (E18) or Day 19 (E19) rat fetuses received oral lavage with either 0.15 or 0.30% saccharin (SAC). Subsequently, observations of orofacial movements (mouthing and licking) following oral lavage with 0.30% SAC were made 50 min later, 24 hr later, or on postnatal Day 3 (P3). Thus, some animals were in a "shifted" condition in which they first experienced a relatively low concentration of SAC and then a higher one while control rats ("nonshifted") received 0.30% SAC during both taste exposures. Fetuses exhibited evidence of both habituation (with repeated presentation of the 0.30% SAC) and positive contrast effects (PCEs) (following an upward shift in SAC concentration) when retested 50 min after their first exposure to SAC on E19. However, these animals did not exhibit PCEs 24 hr later or 5 days later (on P3). Contrast effects were not observed when the initial SAC exposure was on E18, and habituation responses were variable depending on the time interval between the taste presentations to these animals. Rats with a 5- to 6-day latency between the two taste presentations showed neither PCEs nor habituation. Our data indicate that PCEs and habituation effects emerge at different ages, and their demonstration is dependent upon the latency between the taste presentations. © 2004 Wiley Periodicals, Inc. Dev Psychobiol 44: 176,188, 2004. [source] Current management of esophageal perforation: 20 years experienceDISEASES OF THE ESOPHAGUS, Issue 4 2009A. Eroglu SUMMARY Esophageal perforations are surgical emergencies associated with high morbidity and mortality rates. No single strategy has been sufficient to deal with the majority of situations. We aim to postulate a therapeutic algorithm for this complication based on 20 years of experience and also on data from published literature. We performed a retrospective clinical review of 44 patients treated for esophageal perforation at our hospital between January 1989 and May 2008. We reviewed the characteristics of these patients, including age, gender, accompanying diseases, etiology of perforation, diagnosis, location, time interval between perforation and diagnosis, treatment of the perforation, morbidity, hospital mortality, and duration of hospitalization. Perforation occurred in the cervical esophagus in 14 patients (31.8%), thoracic esophagus in 18 patients (40.9%), and abdominal esophagus in 12 patients (27.3%). Management of the esophageal perforation included primary closure in 23 patients (52.3%), resection in 7 patients (15.9%), and nonsurgical therapy in 14 patients (31.8%). In the surgically treated group, the mortality rate was 3 of 30 patients (10%), and 2 of 14 patients (14.3%) in the conservatively managed group. Four of the 14 nonsurgical patients were inserted with covered self-expandable stents. The specific treatment of an esophageal perforation should be selected according to each individual patient. To date, the most effective treatment would appear to be operative management. With improvements in endoscopic procedures, the morbidity and mortality rates of esophageal perforations are significantly decreased. We suggest that minimally invasive techniques for the repair of esophageal perforations will be very important in the future treatment of this condition. [source] Surgery in thoracic esophageal perforation: primary repair is feasibleDISEASES OF THE ESOPHAGUS, Issue 3 2002S. W. Sung SUMMARY. Prompt diagnosis and effective treatment are important for thoracic esophageal perforations. The decision for proper management is difficult especially when diagnosed late. However, there is an increasing consensus that primary repair provides good results for repair of thoracic esophageal perforations, which are not diagnosed on time. Primary repair for thoracic esophageal perforations was applied in 20 out of 25 consecutive patients. The time interval between perforation and repair was less than 24 h in six patients (group I), and more than 24 h in 14 patients (group II). The remaining five patients underwent esophagectomy with simultaneous or staged reconstruction because of incorrectable underlying esophageal pathology. Group I had much more iatrogenic causes (P < 0.05). Preoperative sepsis occurred only in group II (P=0.05) and was highly associated with Boerhaave syndrome (P=0.001). Regional viable tissue was used to reinforce the sites of primary repair (n=15, 75%). All of the postoperative morbidity (n=9, 45%) including esophageal leaks (n=6, 30%) and operative death (n=1, 5%) occurred in group II. In patients with postoperative leaks, five eventually healed, but one became a fistula that required reoperation. Primary healing with preservation of the native esophagus was achieved in all 19 patients except one operative death. In addition, the increased incidence of leak and morbidity did not lead to an increase in mortality. In the esophagectomy group, there was no mortality, but one minor suture leak. Regardless of the time interval between the injury and the operation, primary repair is recommended for non-malignant, thoracic, esophageal perforations, but not for anastomotic leaks. Reinforcement that may change the nature of a possible leak is also useful. For incorrectable underlying esophageal pathology, esophagectomy with simultaneous or staged reconstruction is indicated. [source] Solution of the linear diffusion equation for modelling erosion processes with a time varying diffusion coefficientEARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2008Georgios Aim. Abstract In the present paper the differential equation of the temporal development of a landform (mountain) with a time dependent diffusion coefficient is solved. It is shown that the shape and dimensions of the landform at time t are independent of the specific variation of the diffusion coefficient with time; they only depend on the mean value of the diffusion coefficient in the time interval where the erosion process takes place. Studying the behaviour of the solution of the differential equation in the wave number domain, it is concluded that Fourier analysis may help in estimating, in quantitative terms, the initial dimensions, the age or, alternatively, the value of the diffusion coefficient of the landform. The theoretical predictions are tested on a hill of the southern part of the Ural mountainous region, in order to show how the results of the mathematical analysis can be used in describing, in quantitative terms, the morphological development of landforms due to erosion processes. Copyright © 2007 John Wiley & Sons, Ltd. [source] Dating young geomorphic surfaces using age of colonizing Douglas fir in southwestern Washington and northwestern Oregon, USA,EARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2007Thomas C. Pierson Abstract Dating of dynamic, young (<500 years) geomorphic landforms, particularly volcanofluvial features, requires higher precision than is possible with radiocarbon dating. Minimum ages of recently created landforms have long been obtained from tree-ring ages of the oldest trees growing on new surfaces. But to estimate the year of landform creation requires that two time corrections be added to tree ages obtained from increment cores: (1) the time interval between stabilization of the new landform surface and germination of the sampled trees (germination lag time or GLT); and (2) the interval between seedling germination and growth to sampling height, if the trees are not cored at ground level. The sum of these two time intervals is the colonization time gap (CTG). Such time corrections have been needed for more precise dating of terraces and floodplains in lowland river valleys in the Cascade Range, where significant eruption-induced lateral shifting and vertical aggradation of channels can occur over years to decades, and where timing of such geomorphic changes can be critical to emergency planning. Earliest colonizing Douglas fir (Pseudotsuga menziesii) were sampled for tree-ring dating at eight sites on lowland (<750 m a.s.l.), recently formed surfaces of known age near three Cascade volcanoes , Mount Rainier, Mount St. Helens and Mount Hood , in southwestern Washington and northwestern Oregon. Increment cores or stem sections were taken at breast height and, where possible, at ground level from the largest, oldest-looking trees at each study site. At least ten trees were sampled at each site unless the total of early colonizers was less. Results indicate that a correction of four years should be used for GLT and 10 years for CTG if the single largest (and presumed oldest) Douglas fir growing on a surface of unknown age is sampled. This approach would have a potential error of up to 20 years. Error can be reduced by sampling the five largest Douglas fir instead of the single largest. A GLT correction of 5 years should be added to the mean ring-count age of the five largest trees growing on the surface being dated, if the trees are cored at ground level. This correction would have an approximate error of ±5 years. If the trees are cored at about 1·4 m above the ground surface (breast height), a CTG correction of 11 years should be added to the mean age of the five sampled trees (with an error of about ±7 years). Published in 2006 by John Wiley & Sons, Ltd. [source] On-line identification of non-linear hysteretic structural systems using a variable trace approachEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 9 2001Jeng-Wen Lin Abstract In this paper, an adaptive on-line parametric identification algorithm based on the variable trace approach is presented for the identification of non-linear hysteretic structures. At each time step, this recursive least-square-based algorithm upgrades the diagonal elements of the adaptation gain matrix by comparing the values of estimated parameters between two consecutive time steps. Such an approach will enforce a smooth convergence of the parameter values, a fast tracking of the parameter changes and will remain adaptive as time progresses. The effectiveness and efficiency of the proposed algorithm is shown by considering the effects of excitation amplitude, of the measurement units, of larger sampling time interval and of measurement noise. The cases of exact-, under-, over-parameterization of the structural model have been analysed. The proposed algorithm is also quite effective in identifying time-varying structural parameters to simulate cumulative damage in structural systems. Copyright © 2001 John Wiley & Sons, Ltd. [source] New Annular Tissue Doppler Markers of Pulmonary HypertensionECHOCARDIOGRAPHY, Issue 8 2010Angel López-Candales M.D., F.A.C.C., F.A.S.E. Background: Tissue Doppler imaging (TDI) of mitral (MA) and tricuspid annulus (TA) events characterizes systolic and diastolic properties of each respective ventricle. However, the effect of chronic pulmonary hypertension (cPH) on these TDI annular events has not been well described. Methods: Measurements of right ventricular (RV) performance with TDI of the lateral mitral and tricuspid annuli, to measure isovolumic contraction (IVC) and systolic (S) signals were recorded from 50 individuals without PH and from 50 patients with cPH. To avoid confounding variables, all patients had normal left ventricular ejection fraction and were in normal sinus rhythm at the time of the examination. Results: As expected, markers of RV systolic performance were markedly reduced while LV systolic function remained largely unaffected in cPH patients when compared to patients without PH. TDI interrogation of the MA revealed lengthening of the time interval between IVC and systolic signal (70 ± 17 msec) when compared to individuals without PH (43 ± 8 msec; P < 0.0001). In contrast, cPH markedly shortened the time interval between IVC and the TA systolic signal (34 ± 12 msec) when compared to individuals without PH (65 ± 17 msec; P < 0.0001). Conclusions: cPH lengthens time interval between the IVC and the MA systolic signal while shortening this same interval when the TA is interrogated with TDI; reflecting the potential influence that cPH exerts in biventricular performance. Whether measuring these intervals be routinely used in the follow-up of cPH patients will require further study. (Echocardiography 2010;27:969-976) [source] ORIGINAL INVESTIGATIONS: Tissue Harmonic Imaging in Echocardiography: Better Valve Imaging, But at What Cost?ECHOCARDIOGRAPHY, Issue 2 2008Karin Hawkins M.D. Background: Tissue harmonic imaging (THI) improves echocardiographic image quality and is widely utilized. Unfortunately it also makes structures appear artificially thickened. We sought to examine its impact on the imaging of left-sided heart valves. Methods: A large echocardiographic database was searched for full, standard transthoracic echocardiographic exams performed 12-month periods before (n = 3,786) and after (n = 3,914) transition to THI at a single institution. Patients with prosthetic valves were excluded. Results: The mean age of patients was 63 ± 17 years and 65% were men. No appreciable difference in demographics was observed between time periods. While inadequate visualization of the mitral valve was reduced by 30% using THI (P = 0.014), reports of leaflet thickening increased by 28% (P = 0.005). Similarly, inadequate aortic valve visualization was reduced by 53% with THI (P < 0.001), at the expense of more aortic sclerosis (+6%, P = 0.034). Among the 480 patients with echocardiograms using each modality (time interval between studies: 370 ± 143 days), THI did not appreciably improve visualization of the either valve. Although no significant increase in mitral thickness was seen with THI, aortic sclerosis was increased by at least one grade in 24.5% (P < 0.006). Conclusion: This study suggests that while THI enhances imaging of difficult to visualize valves, it may overestimate mitral and aortic valve thickness. This could lead to overdiagnosis and unnecessary follow-up studies. Cardiologists interpreting THI echocardiograms should become familiar with the modality's shortcomings. [source] Catheterization,Doppler Discrepancies in Nonsimultaneous Evaluations of Aortic StenosisECHOCARDIOGRAPHY, Issue 5 2005Payam Aghassi M.D. Prior validation studies have established that simultaneously measured catheter (cath) and Doppler mean pressure gradients (MPG) correlate closely in evaluation of aortic stenosis (AS). In clinical practice, however, cath and Doppler are rarely performed simultaneously; which may lead to discrepant results. Accordingly, our aim was to ascertain agreement between these methods and investigate factors associated with discrepant results. We reviewed findings in 100 consecutive evaluations for AS performed in 97 patients (mean age 72 ± 10 yr) in which cath and Doppler were performed within 6 weeks. We recorded MPG, aortic valve area (AVA), cardiac output, and ejection fraction (EF) by both methods. Aortic root diameter, left ventricular end-diastolic dimension (LVIDd) and posterior wall thickness (PWT) were measured by echocardiography and gender, heart rate, and heart rhythm were also recorded. An MPG discrepancy was defined as an intrapatient difference > 10 mmHg. Mean pressure gradients by cath and Doppler were 36 ± 22 mmHg and 37 ± 20 mmHg, respectively (P = 0.73). Linear regression showed good correlation (r = 0.82) between the techniques. An MPG discrepancy was found in 36 (36%) of 100 evaluations; in 19 (53%) of 36 evaluations MPG by Doppler was higher than cath, and in 17 (47%) of 36, it was lower. In 33 evaluations, EF differed by >10% between techniques. Linear regression analyses revealed that EF difference between studies was a significant predictor of MPG discrepancy (P = 0.004). Women had significantly higher MPG than men by both cath and Doppler (43 ± 25 mmHg versus 29 ± 15 mmHg [P = 0.001]; 42 ± 23 mmHg versus 32 ± 15 mmHg [P = 0.014], respectively). Women exhibited discrepant results in 23 (47%) of 49 evaluations versus 13 (25%) of 51 evaluations in men (P = 0.037). After adjustment for women's higher MPG, there was no statistically significant difference in MPG discrepancy between genders (P = 0.22). No significant interactions between MPG and aortic root diameter, relative wall thickness (RWT), heart rate, heart rhythm, cardiac output, and time interval between studies were found. In clinical practice, significant discrepancies in MPG were common when cath and Doppler are performed nonsimultaneously. No systematic bias was observed and Doppler results were as likely yield lower as higher MPGs than cath. EF difference was a significant predictor of discrepant MPG. Aortic root diameter, relative wall thickness, heart rate, heart rhythm, cardiac output, presence or severity of coronary artery disease, and time interval between studies were not predictors of discrepant results. [source] Modified TEI Index: A Promising Parameter in Essential Hypertension?ECHOCARDIOGRAPHY, Issue 4 2005Nurgül Keser M.D. Purpose: Modified TEI index is pointed to be more effective in the evaluation of global cardiac functions compared to systolic and diastolic measurements alone. We planned to determine its applicability in hypertension and relation with left ventricular mass index (LVMI). Methods: We studied 48 patients with mild/moderate hypertension and normal coronary angiograms. In total 22 patients (12 men, 10 women, mean age: 55 ± 6) with normal LVMI were studied in group I, 26 patients (12 men, 14 women, mean age: 57 ± 7) with increased LVMI in group II, and 20 patients (10 men, 10 women, mean age: 53 ± 7) with normal blood pressure as a control group. Standard 2D, Doppler, and mitral annulus pulse wave tissue Doppler were used for all measurements. Modified TEI index was calculated as diastolic time interval measured from end of Am wave to origin of Em (a,) minus systolic Sm duration (b,) divided by b(a,,b,/b,). Results: Modified TEI index was significantly higher in both groups than normal group and in group II than in group I. (Control group: 0.33 ± 0.05, group I: 0.51 ± 0.17, group II: 0.68 ± 0.16, P< 0.0001). Conclusion: Modified TEI index, a marker of left ventricular systolic and diastolic functions, is impaired in hypertensives before hypertrophy develops and impairment is more prominent in hypertrophy. Therefore, (1) modified TEI index in hypertensives is a safe, feasible, and sensitive index for evaluation of global ventricular functions. (2) Evaluation of hypertensives with this index periodically may guide interventions directed toward saving systolic and diastolic functions. (3) Modified TEI index is gaining importance as a complementary parameter to standard Doppler or in cases where standard Doppler has its limitations. [source] The costs and benefits of fast livingECOLOGY LETTERS, Issue 12 2009Karen E. Rose Abstract Growth rates play a fundamental role in many areas of biology (Q. Rev. Biol., 67, 1992, 283; Life History Invariants. Some Explorations of Symmetry in Evolutionary Biology, 1993; Philos. Trans. R. Soc. Lond. B Biol. Sci., 351, 1996, 1341; Plant Strategies, Vegetation Processes, and Ecosystem Properties, 2002; Trends Ecol. Evol., 18, 2003, 471; Q. Rev. Biol., 78, 2003, 23; J. Ecol., 95, 2007, 926.) but the cost and benefits of different growth rates are notoriously difficult to quantify (Q. Rev. Biol., 72, 1997, 149; Funct. Ecol., 17, 2003, 328). This is because (1) growth rate typically declines with size and yet the most widely used growth measure , relative growth rate or RGR (conventionally measured as the log of the ratio of successive sizes divided by the time interval) , is not size-corrected and so confounds growth and size, (2) organisms have access to different amounts of resource and (3) it is essential to allow for the long-term benefits of larger size. Here we experimentally demonstrate delayed costs and benefits of rapid growth in seven plant species using a novel method to calculate size-corrected RGR. In control treatments, fast-growing plants benefited from increased reproduction the following year; however, fast-growing plants subjected to an experimental stress treatment (defoliation) showed strongly reduced survival and reproduction the following year. Importantly, when growth was estimated using the classical RGR measure, no costs or benefits were found. These results support the idea that life-history trade-offs have a dominant role in life-history and ecological theory and that the widespread failure to detect them is partly due to methodological shortcomings. Ecology Letters (2009) 12: 1379,1384 [source] Consistent High-precision Volatility from High-frequency DataECONOMIC NOTES, Issue 2 2001Fulvio Corsi Estimates of daily volatility are investigated. Realized volatility can be computed from returns observed over time intervals of different sizes. For simple statistical reasons, volatility estimators based on high-frequency returns have been proposed, but such estimators are found to be strongly biased as compared to volatilities of daily returns. This bias originates from microstructure effects in the price formation. For foreign exchange, the relevant microstructure effect is the incoherent price formation, which leads to a strong negative first-order autocorrelation ,(1),40 per cent for tick-by-tick returns and to the volatility bias. On the basis of a simple theoretical model for foreign exchange data, the incoherent term can be filtered away from the tick-by-tick price series. With filtered prices, the daily volatility can be estimated using the information contained in high-frequency data, providing a high-precision measure of volatility at any time interval. (J.E.L.: C13, C22, C81). [source] Long-term Prognosis and Psychosocial Outcomes after Surgery for MTLEEPILEPSIA, Issue 12 2006Sophie Dupont Summary:,Purpose: To assess the seizure-freedom rates and self-perceived psychosocial changes associated with the long-term outcome of epilepsy surgery in patients with refractory medial temporal lobe epilepsy associated with hippocampal sclerosis. Methods: A standard questionnaire was given to 183 patients who underwent surgery between 1988 and 2004, and 110 were completed. Results: The mean duration of follow-up after surgery was 7 years, with a maximum of 17 years. The probability that patients were seizure-free after surgery was dependent on the definition of the seizure freedom. For the patients who were seizure-free since surgery (Engel's class Ia), the probability was 97.6% at 1 year after surgery, 85.2% at 2 years after surgery, 59.5% at 5 years after surgery, and 42.6% at 10 years after surgery. For the patients who still experienced rare disabling seizures after surgery but were seizure-free at least 1 year before the time of assessment, the probability was of 97.6% at 1 year after surgery, 95% at 2 years after surgery, 82.8% at 5 years after surgery, and 71.1% at 10 years after surgery. The psychosocial long-term outcome, as measured by indices of driving, employment, familial and social relationships, and marital status, was similar to the psychosocial short-term outcome. It did not depend on seizure freedom or on follow-up time interval and was not influenced statistically by seizure frequency in cases of persisting seizures. Most but not all patients noticed a substantial overall improvement in their psychosocial condition; 48% drove (increased by 7%), 47% improved (14% worsened) in their employment status, and 68% improved (5% worsened) in their familial and social relationships. Overall, 91% of patients were satisfied with the surgery, and 92% did not regret their decision. Conclusions: The results of this study suggest that temporal lobe surgery has real long-term benefits. Two specific conclusions emerge: (a) the long-term rates of freedom from seizure depend on how seizure freedom is defined, and (b) the psychosocial long-term outcome does not change dramatically over years and does not depend on seizure freedom. [source] Epilepsy Can Be Diagnosed When the First Two Seizures Occur on the Same DayEPILEPSIA, Issue 9 2000Peter Camfield Summary: Purpose: Experts have suggested that when the first two (or more) unprovoked seizures occur on the same day, they should be considered as a single event and the diagnosis of epilepsy await a further seizure. We have studied the subsequent clinical course of children with their first two seizures on the same day ("same day" group) compared with children with their first two seizures separated by more than one day ("different day" group). Method: The Nova Scotia childhood epilepsy database documented all newly diagnosed children with epilepsy from 1977 to 1985 with follow-up in 1990 and 1991. Epilepsy was defined as two or more unprovoked seizures regardless of the interval between seizures provided that consciousness fully returned between seizures. All patients had their first seizure between the ages of 1 month and 16 years. Seizure types were restricted to partial, generalized tonic-clonic, and partial with secondary generalization. Results: Of the 490 children with partial or generalized tonic-clonic seizures and follow-up of more than 2 years, 70 had their first two or more seizures on the same day and 420 had their first two seizures on different days. Eighty percent (56 of 70) of the "same day" group subsequently had one or more further seizures with (n = 14) or without (n = 42) medication; 80.9% (340 of 420) of the "different day" group had one or more further seizures with (n = 115) or without (n = 225) medication. Seizure types were nearly identical. Cause was the same (except for fewer idiopathic "genetic" cases in the "same day" group: 1 of 70 vs. 42 of 420; p = 0.02). Rates of mental handicap and previous febrile seizures were the same. Children in the "same day" group were younger on average (60 vs. 84 months; p = 0.001) and were somewhat more likely to have neurological impairment. Outcome after 7 years average follow-up was the same: 58% of the "same day" group and 56% of the "different day" group were in remission. Conclusion: If two or more unprovoked seizures (with normal consciousness between) occur on the same day, the child appears to have epilepsy and will have a clinical course identical to that of the child with a longer time interval between the first two seizures. [source] Effects of unilateral laser-assisted ventriculocordectomy in horses with laryngeal hemiplegiaEQUINE VETERINARY JOURNAL, Issue 6 2006P. ROBINSON Summary Reasons for performing study: Recent studies have evaluated surgical techniques aimed at reducing noise and improving airway function in horses with recurrent laryngeal neuropathy (RLN). These techniques require general anaesthesia and are invasive. A minimally invasive transnasal surgical technique for treatment of RLN that may be employed in the standing, sedated horse would be advantageous. Objective: To determine whether unilateral laser-assisted ventriculocordectomy (LVC) improves upper airway function and reduces noise during inhalation in exercising horses with laryngeal hemiplegia (LH). Methods: Six Standardbred horses were used; respiratory sound and inspiratory transupper airway pressure (Pui) measured before and after induction of LH, and 60, 90 and 120 days after LVC. Inspiratory sound level (SL) and the sound intensities of formants 1, 2 and 3 (F1, F2 and F3, respectively), were measured using computer-based sound analysis programmes. In addition, upper airway endoscopy was performed at each time interval, at rest and during treadmill exercise. Results: In LH-affected horses, Pui, SL and the sound intensity of F2 and F3 were increased significantly from baseline values. At 60 days after LVC, Pui and SL had returned to baseline, and F2 and F3 values had improved partially compared to LH values. At 90 and 120 days, however, SL increased again to LH levels. Conclusions: LVC decreases LH-associated airway obstruction by 60 days after surgery, and reduces inspiratory noise but not as effectively as bilateral ventriculocordectomy. Potential relevance: LVC may be recommended as a treatment of LH, where reduction of upper airway obstruction and respiratory noise is desired and the owner wishes to avoid risks associated with a laryngotomy incision or general anaesthesia. [source] Cardiopulmonary, blood and peritoneal fluid alterations associated with abdominal insufflation of carbon dioxide in standing horsesEQUINE VETERINARY JOURNAL, Issue 3 2003F. G. LATIMER Summary Reasons for performing study: Abdominal insufflation is performed routinely during laparoscopy in horses to improve visualisation and facilitate instrument and visceral manipulations during surgery. It has been shown that high-pressure pneumoperitoneum with carbon dioxide (CO2) has deleterious cardiopulmonary effects in dorsally recumbent, mechanically ventilated, halothane-anaesthetised horses. There is no information on the effects of CO2 pneumoperitoneum on cardiopulmonary function and haematology, plasma chemistry and peritoneal fluid (PF) variables in standing sedated horses during laparoscopic surgery. Objectives: To determine the effects of high pressure CO2 pneumoperitoneum in standing sedated horses on cardiopulmonary function, blood gas, haematology, plasma chemistry and PF variables. Methods: Six healthy, mature horses were sedated with an i.v. bolus of detomidine (0.02 mg/kg bwt) and butorphanol (0.02 mg/kg bwt) and instrumented to determine the changes in cardiopulmonary function, haematology, serum chemistry and PF values during and after pneumoperitoneum with CO2 to 15 mmHg pressure for standing laparoscopy. Each horse was assigned at random to either a standing left flank exploratory laparoscopy (LFL) with CO2 pneumoperitoneum or sham procedure (SLFL) without insufflation, and instrumented for measurement of cardiopulmonary variables. Each horse underwent a second procedure in crossover fashion one month later so that all 6 horses had both an LFL and SLFL performed. Cardiopulmonary variables and blood gas analyses were obtained 5 mins after sedation and every 15 mins during 60 mins baseline (BL), insufflation (15 mmHg) and desufflation. Haematology, serum chemistry analysis and PF analysis were performed at BL, insufflation and desufflation, and 24 h after the conclusion of each procedure. Results: Significant decreases in heart rate, cardiac output and cardiac index and significant increases in mean right atrial pressure, systemic vascular resistance and pulmonary vascular resistance were recorded immediately after and during sedation in both groups of horses. Pneumoperitoneum with CO2 at 15 mmHg had no significant effect on cardiopulmonary function during surgery. There were no significant differences in blood gas, haematology or plasma chemistry values within or between groups at any time interval during the study. There was a significant increase in the PF total nucleated cell count 24 h following LFL compared to baseline values for LFL or SLFL at 24 h. There were no differences in PF protein concentrations within or between groups at any time interval. Conclusions: Pneumoperitoneum with CO2 during standing laparoscopy in healthy horses does not cause adverse alterations in cardiopulmonary, haematology or plasma chemistry variables, but does induce a mild inflammatory response within the peritoneal cavity. Potential relevance: High pressure (15 mmHg) pneumoperitoneum in standing sedated mature horses for laparoscopic surgery can be performed safely without any short-term or cumulative adverse effects on haemodynamic or cardiopulmonary function. [source] Variation and Repeatability of Female Choice in a Chorusing Katydid, Ephippiger ephippiger: an Experimental Exploration of the Precedence EffectETHOLOGY, Issue 4 2004Michael D. Greenfield Female choice in various species of acoustic insects and anurans entails a psychoacoustic preference for male calls that lead their neighbors by a brief time interval. This discrimination, which can be termed a precedence effect, may select for various mechanisms with which males adjust call rhythm and thus reduce their incidence of ineffective following calls. At a collective level, alternating and synchronous choruses may emerge from these call timing mechanisms. Using playback experiments, we characterized the precedence effect in females of the katydid Ephippiger ephippiger, an alternating choruser in which males use a rhythm adjustment mechanism that prevents calling during brief intervals following their neighbors' calls. E. ephippiger females oriented toward leading male calls in >75% of trials when relatively young (<40 d old) and when playbacks were timed so that following calls began within 100,250 ms of the leading ones. However, this preference declined to below 60% as females aged and the interval separating leading and following call onsets increased. The strength of this precedence effect varied greatly between females, but within broad age classes the effect in a given female was statistically repeatable. Such repeatability indicates the possibility that additive genetic variance could be a significant component of variation in the precedence effect. We discuss the implications of our findings and inference on genetic variance for evolution of the precedence effect and for chorusing. [source] Ruptured symptomatic internal carotid artery dorsal wall aneurysm with rapid configurational change.EUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2010Clinical experience, management outcome: an original article Background:, Aneurysms located at non-branching sites, protruding from the dorsal wall of the supraclinoid internal carotid artery (ICA) with rapid configurational changes, were retrospectively reviewed in effort to identify and characterize these high-risk aneurysms. Methods:, A total of 447 patients with 491 intracranial aneurysms were treated from March 2005 to August 2008, and of these, eight patients had ICA dorsal wall aneurysms. Four of them suffered subarachnoid hemorrhage (SAH), and all had aneurysms undergoing rapid configuration changes during the treatment course. Digital subtraction cerebral angiography (DSA) performed soon after the SAH events. Data analyzed were patient age, sex, Hunt and Kosnik grade, time interval from first DSA to second DSA, aneurysm treatment, and modified Rankin scale score after treatment for 3 months. Success or failure of therapeutic management was examined among the patients. Results:, Digital subtraction cerebral angiography showed only lesions with small bulges in the dorsal walls of the ICAs. However, the patients underwent DSA again for re-bleeding or for post-treatment follow-up, confirming the SAH source. ICA dorsal wall aneurysms with rapid growth and configurational changes were found on subsequent DSA studies. Conclusions:, Among the four patients, ICA dorsal wall aneurysms underwent rapid growth with configurational change from a blister type to a saccular type despite different management. ICA trapping including the lesion segment can be considered as the first treatment option if the balloon occlusion test (BOT) is successful. If a BOT is not tolerated by the patient, extracranial,intracranial bypass revascularization surgery with endovascular ICA occlusion is another treatment option. [source] A comparison between two-dimensional and three-dimensional cephalometry on frontal radiographs and on cone beam computed tomography scans of human skullsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2009Olivier J. C. Van Vlijmen The aim of this study was to evaluate whether measurements performed on conventional frontal radiographs are comparable to measurements performed on three-dimensional (3D) models of human skulls derived from cone beam computed tomography (CBCT) scans and if the latter can be used in longitudinal studies. Cone beam computed tomography scans and conventional frontal cephalometric radiographs were made of 40 dry human skulls. From the CBCT scan a 3D model was constructed. Standard cephalometric software was used to identify landmarks and to calculate ratios and angles. The same operator identified 10 landmarks on both types of cephalometric radiographs, and on all images, five times with a time interval of 1 wk. Intra-observer reliability was acceptable for all measurements. There was a statistically significant and clinically relevant difference between measurements performed on conventional frontal radiographs and on 3D CBCT-derived models of the same skull. There was a clinically relevant difference between angular measurements performed on conventional frontal cephalometric radiographs, compared with measurements performed on 3D models constructed from CBCT scans. We therefore recommend that 3D models should not be used for longitudinal research in cases where there are only two-dimensional (2D) records from the past. [source] The Efficacy of Esmolol versus Lidocaine to Attenuate the Hemodynamic Response to Intubation in Isolated Head Trauma PatientsACADEMIC EMERGENCY MEDICINE, Issue 1 2001M. Andrew Levitt DO Abstract. Objective: To assess the effect of esmolol vs lidocaine to attenuate the detrimental rise in heart rate and blood pressure during intubation of patients with isolated head trauma. Methods: This was a prospective, double-blind, randomized study, performed at an urban, county teaching emergency department. Participants were 30 patients with isolated head trauma. Each underwent a standardized intubation protocol including esmolol or lidocaine, both at 2 mg/kg. Results: Esmolol was used in 16 patients and lidocaine in 14. Mechanisms of injury included 12 assaults, 6 motor vehicle collisions, 6 falls, 4 auto-vs-pedestrian crashes, and 2 bicycle incidents. Mean ethanol level was 0.116 ± 0.133 SD (range 0-0.482). Mean Glasgow Coma Scale (GCS) score was 7.9 ± 4.0 SD. Cranial computed tomography (CT) hemorrhagic findings included 9 subdural/epidural hematomas, 6 cortex hemorrhages, and 2 multi-hemorrhages. Eleven patients received surgical intervention: 9 patients received a craniotomy, and 2 a ventricular catheter. The 2-minute time interval around intubation was used to assess each drug's efficacy. The mean difference change between groups for heart rate was 4.0 beats/min (95% CI = -17.7 to 9.7 beats/min), for systolic blood pressure was 1.3 mm Hg (95% CI = -27.8 to 30.4 mm Hg), and for diastolic blood pressure was 2.6 mm Hg (95% CI = -27.1 to 21.9 mm Hg). The power of this study was 90% to detect a 20-beat/min difference in heart rate, a 35-mm Hg difference in systolic blood pressure, and a 20-mm Hg difference in diastolic blood pressure. Conclusions: Esmolol and lidocaine have similar efficacies to attenuate moderate hemodynamic response to intubation of patients with isolated head trauma. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||