Response-time Relationships Research Articles

Faktor – Faktor Yang Mempengaruhi Kecemasan Keluarga Pasien Pada Saat Dilakukan Triage Di IGD RSUD Dr. Haryoto Lumajang

The large number of patient visits to the emergency room requires a triage system to sort out patients who are prioritized to get service first to anticipate patient overcrowding and avoid patients who are not helped or die due to not getting fast help. The distribution of triage is one of the common causes for families to feel anxious. Moreover, if the family does not understand the triage system used, they will feel ignored and afraid if their family members do not get health services immediately. This study aims to determine the anxiety of the patient's family when triage is carried out in the emergency room.
 This study used an observational design with a cross-sectional approach, a sample of 95 people. Data collection used a questionnaire. Bivariate analysis used the Chi Square test. Multivariate analysis used the Logistic Regression Test. The statistical test results obtained a p value = 0.05, namely there is a response time relationship. nurses with patient family anxiety during triage in the ER, there is a relationship between nurse therapeutic communication and patient family anxiety during triage in the ER, there is a relationship between patient knowledge/information and patient family anxiety during triage in the ER, there are factors that have the most influence to the level of anxiety.
 There is a relationship between nurse response time, there is a relationship with nurse therapeutic communication, there is a relationship with patient knowledge/information and the factors that most influence the anxiety level of the patient's family when triage is carried out in the emergency room of RSUD dr. Haryoto Lumajang is a nurse therapeutic communication factor.
 
 Keywords: Anxiety of the patient's family, Triage, Emergency Department

Population exposure-response model of 131I in patients with benign thyroid disease

PurposeThe study aimed to explore the relationship of different exposure measures with 131I therapy response in patients with benign thyroid disease, estimate the variability in the response, investigate possible covariates, and discuss dosing implications of the results. MethodsA population exposure-response analysis was performed using nonlinear mixed-effects modelling. Data from 95 adult patients with benign thyroid disease were analysed. Evaluated exposure parameters were: administered radioactivity dose (Aa) [MBq], total absorbed dose (ABD) [Gy], maximum of absorbed dose-rate (MXR) [Gy/h] and biologically effective dose (BED) [Gy]. The response was modelled as ordered categorical data: hyper-, eu- and hypothyroidism. The final model performance was evaluated by a visual predictive check. ResultsThe probability of the outcome following 131I therapy was best described by a proportional-odds model, including the log-linear model of 131I effect and the exponential model of the response-time relationship. All exposure measures were statistically significant with p<0.001, with BED and ABD being statistically better than the other two. Nevertheless, as BED resulted in the lowest AIC value, it was included in the final model. Accordingly, BED value of 289.7 Gy is associated with 80% probability of successful treatment outcome 12 months after 131I application in patients with median thyroid volume (32.28 mL). The target thyroid volume was a statistically significant covariate. The visual predictive check of the final model showed good model performance. ConclusionOur results imply that BED formalism could aid in therapy individualisation. The larger thyroid volume is associated with a lower probability of a successful outcome.

The response-time relationship and covariate effects of acupuncture for chronic pain: A systematic review and model-based longitudinal meta-analysis.

Critical clinical questions regarding how soon and how long the analgesic effect will be achieved by acupuncture, as well as who will be responsive to acupuncture, need further address. The aim of the study was to investigate the response-time relationship and covariate effects of acupuncture. PubMed and EMBASE were searched up to December 2018 for randomized controlled trials that involved sham acupuncture, true acupuncture and conventional therapy. We used a model-based longitudinal meta-analysis to characterize the response-time profile of these treatments. Seventy-seven randomized clinical trials involved chronic shoulder, neck, knee and low back pain were included. The response-time analysis suggested that the treatment duration of acupuncture will be 5weeks or more to achieve 80% of maximum analgesic effect. Moreover a lower baseline pain intensity and the location of low back pain resulted in a lower pain relief of acupuncture intervention. The absolute maximum analgesic effects of sham acupuncture and conventional therapy were 22.6 and 15.8 points at a 0-100 NRS scale. The absolute effect of true acupuncture was 26.1 points for low back pain (relative effect of 3.5 and 9.4 points to sham and conventional therapy), 34.9 points for other pain body locations (relative effect of 12.3 and 19.1 points to sham and conventional therapy), in patients with a baseline pain intensity of 60 points. The treatment duration of acupuncture will not be less than 5weeks to achieve 80% maximum analgesic effect. Higher analgesic effect was related to higher baseline pain intensity and pain location of neck, shoulder and knee. Our systematic review and meta-analysis provides the clear evidence for the treatment duration and significant related covariates of acupuncture intervention for chronic pain. These results provide useful suggestion for acupuncture intervention in clinical pain management.

Optimising in vivo pharmacology studies—Practical PKPD considerations

Introduction It has become apparent in recent years that there is a need for a substantial improvement in the processes used to clarify the inter-relationships between a compound's pharmacokinetic (PK) characteristics, its target actions and its safety profile. This is particularly challenging because most of the techniques currently used to obtain meaningful data involve low efficiency animal studies. To maximize the value of such in vivo studies, time and resources need to be better utilized. One way of making major advances is to adopt an integrative approach to designing and analysing in vivo pharmacodynamic (PD) studies. In this paper we address experimental design issues related to maximizing the information content about target engagement. Refined integration of PK and PD (known as ‘quantitative pharmacology’ or a PKPD approach) is advocated, enabling clarification of the interdependence of a drug's pharmacological properties on its target physiological system(s) and its systemic exposure characteristics. Methods Several in vivo pharmacological Case Studies are presented which are used to illustrate the discussion of issues of experimental design. The impact of rate, extent and mode of administration is discussed from a pharmacological viewpoint, and we examine the consequences of temporal differences between concentration and response from the perspective of experimental design. We also consider the importance of differences in plasma protein binding (PPB) on our ability to assess a pharmacodynamic property or safety margin, and examine the usefulness of measuring ex vivo PPB. Finally, we outline the value of implementing a clearly pre-determined, integrated work flow to generate, validate and maximize in vivo PKPD or preclinical disease model data, and summarize the key issues of experimental design. Results and discussion Quantitative pharmacological reasoning focuses on concentration–response and response-time relationships with special emphasis on the impact of drugs on disease (Levy, 1993) and this perspective was written to raise awareness among in vivo scientists as to why PKPD integration is essential in their studies.

Quantitative Pharmacology or Pharmacokinetic Pharmacodynamic Integration Should Be a Vital Component in Integrative Pharmacology

Pharmacodynamics (PD) examines the relationship between drug concentration and onset, intensity, and duration of the pharmacological effect. Pharmacokinetics (PK) is the science of the time course of drugs in the organism. The quantitative pharmacological approach focuses on concentration-response and response-time relationships, with special emphasis on the proposed impact of the drug on the disease. The review aims to raise awareness among pharmacologists with regard to why pharmacokinetic-pharmacodynamic (PKPD) integration is essential in basic pharmacology research to improve interpretation of data. Quantitative pharmacology is vital in drug discovery for target validation, optimizing the development of lead compounds, and scaling compounds to humans and has become mandatory for regulatory bodies. However, its use is still comparatively rare in experimental pharmacology, and its absence diminishes the interpretative value of published experimental data and can allow the presentation of misleading information. A primary requirement for PKPD integration is establishing the inter-relationships between in vitro and in vivo PK and PD properties and extrapolation to the known or possible future clinical use of a compound. This review examines the use of PKPD in experimental pharmacology by reviewing drug exposure measurements, plasma protein binding, exposure-effect relationships, and the measurement of active metabolites. It examines the significance of dosing schedules, the importance of target engagement, and problems in examining time-response relationships. It shows how quantitative pharmacology adds significant value to study design and examines why ignoring pharmacokinetics can lead to misleading results and conclusions. Finally, a guide list of points to be considered when performing studies is provided.

Recognition instructions and recognition practice can alter the confidence--response time relationship.

Three face-recognition experiments examined how instructions for a recognition test (e.g., emphasize speed or emphasize accuracy) can impact the confidence-response time relationship for episodic memory reports. In all 3 experiments, the confidence-response time correlation was smaller when participants were told to speed up their responding rate, which suggests that participants in these conditions relied less on the artificially compressed response times in forming their confidence judgments than they would under "normal" circumstances. Also, recognition practice before the final memory test eliminated the effect of the recognition instruction manipulation. These results support J. S. Shaw's (1996) suggestion that witnesses rely in part on the fluency of their memory reports when generating confidence judgments, and these findings have important implications for understanding the relationships among witness confidence, accuracy, and response time.

Excimer laser for various degrees of myopia. A new model estimating the immediate response, the regression, the final response and the time relationship.

To demonstrate a unified model for various degrees of myopia, characterizing the response-time relationship and its influence of topical corticosteroids. 84 eyes were treated with excimer laser for myopia (median -7.1 D). 50 eyes received topical NSAID for 4 days (group 1), and 34 eyes (group 2) were further treated postoperatively with bandage lens and topical corticosteroids for three months. The response-time relationship was expressed as P(t)=a+b*exp(k*t), where P(t) is the response expressed as the percent change in dioptric power to the postoperative time t, a is the final percent response, b is the total percent regression and k the time constant. a+b express the percent immediate response and T1/2=0.69/k denote the time within which half of the total regression has occurred. The immediate and final responses were significantly larger in group 2 (128.9% and 70.5%) compared with group 1 (110.5% and 59.8%). T1/2 was significantly longer in group 2 (2.1 month) compared with group 1 (0.8 month) Use of bandage lens together with steroids significantly influences the response-time relationship after excimer laser treatment for myopia.

Trough

EFFECT OF ELIMINATION HALF-LIFE ON TROUGH:PEAK RATIO IN BETA-BLOCKERS: Maximal beta-adrenoceptor blockade and peak blood pressure reduction are achieved with plasma concentrations that are below the peak postdose concentrations observed when therapeutic doses are given. As a result, any trough:peak variation in the blood pressure response is likely to depend on the proportion of the dose interval during which maximal beta-blockade is maintained, and on the relationship between the elimination half-life of the drug, the dose and the dose interval. Acceptable trough:peak ratios (> 70%) for the blood pressure response to beta-blockade with a single daily dose are usually found with drugs that have an elimination half-life of over 6 h or when slow-release preparations are used for drugs with a shorter half-life. OTHER FACTORS THAT INFLUENCE THE TROUGH:PEAK RATIO: The interpretation of trough:peak ratios when beta-blockers are used may be complicated by circadian variations in the blood pressure response, with low blood pressure levels during sleep and an early morning rise upon waking. The blood pressure response-time relationships for beta-blockers with vasodilator properties appear to be similar to those for 'plain' beta-blockers, although there may be greater attenuation of the rise in blood pressure upon waking when multiple-action agents are used. Furthermore, the blood pressure of elderly patients with systolic hypertension may show an attenuated response to beta-blockers, resulting in a less favourable trough:peak ratio. It is not clear whether blood pressure 'responders' to beta-blockers have a pattern of response that is different from the mean of a heterogeneous group. Further studies with appropriate designs are required to clarify these issues.

Physiological pharmacokinetic models: some aspects of theory, practice and potential.

Models are intellectual constructs that pattern selected relationships among the elements of one system to correspond in some way to elements of a second system. In pharmacokinetics, physiological models provide a clearly articulated, rational, explanatory basis for the integration of empirical data; they do this by partitioning the biological system into relevant components (tissues, organs, etc.) and linking them together through the circulatory system. Unlike conventional mammillary compartment models, there is a clear correspondence between model system elements and physiological entities. By virtue of their high degree of physical and biochemical relevance, these models can help provide deep insight into structure, function and mechanism. Pharmacokinetic (and potentially pharmacodynamic) response-time relationships can thus be understood in terms of interconnections and behavior of constituent subsystems. At their worst, these models provide stale or infertile views of reality and thus frustrate and alienate us with the triviality of their insights. At their best, they allow us to understand the accumulation of thought in pharmacokinetics and pharmacodynamics, and help with the integration of data and improvement of experimental design.

Selective alpha 1- and alpha 2-adrenoceptor agonist-induced contractions and 45Ca fluxes in the rat isolated aorta.

1 Contractile responses produced by the alpha 1-adrenoceptor selective agonist, phenylephrine, and the alpha 2-adrenoceptor selective agonists, oxymetazoline and clonidine, have been compared to those produced by noradrenaline (non selective) in the rat aorta. 2 The relative order of potency of the agonists was noradrenaline greater than phenylephrine greater than clonidine greater than oxymetazoline. Noradrenaline and phenylephrine produced similar maximal responses. The maximal responses produced by oxymetazoline and clonidine were about 59% and 24% respectively of those produced by noradrenaline. 3 Concentrations of agonists producing maximal contractions exhibited different response-time relationships. Responses to noradrenaline and phenylephrine were biphasic while responses induced by oxymetazoline and clonidine were monophasic. 4 In calcium-free solution, contractions stimulated by oxymetazoline and clonidine were almost abolished while those stimulated by noradrenaline and phenylephrine were reduced by about 60-70%. The calcium entry blocker, cinnarizine, almost completely inhibited responses to oxymetazoline and clonidine and reduced noradrenaline- and phenylephrine-stimulated responses by about 60%. 5 All the agonists stimulated the uptake of 45Ca into the La3+-resistant Ca2+ fraction of the artery but only noradrenaline and phenylephrine stimulated the efflux of 45Ca into calcium-free solution. The 45Ca uptake stimulated by oxymetazoline and clonidine was abolished by cinnarizine and that stimulated by noradrenaline and phenylephrine was reduced by about 85%. 6 It is concluded that clonidine and oxymetazoline stimulate contractions that are totally dependent on extracellular calcium. Noradrenaline and phenylephrine stimulate contractions that are partly dependent on extracellular calcium and partly dependent on intracellular calcium stores.

Piecewise Linear Approximation of Multivariate Functions

To approximate functions of a single variable by using linear interpolation is routine in empirical studies. Here, we consider approximating functions of several variables in a similar piecewise linear manner. We focus on the nontrivial part of this technique, which is that of choosing the appropriate “pieces” for the piecewise linear approximation. Precisely, we seek to identify the best interpolants to use at a point of interpolation. This is not an issue for functions of a single variable, since the linear ordering of the number line leaves us with no choice. For functions of several variables, we propose several simple tools to help uncover undesirable choices. The techniques presented are useful in the empirical study of quantitatively complex functional relationships whose qualitative behavior is nevertheless known and simple. Response time relationships parametrized by workloads in computer performance modeling often fall into this category, and an actual bivariate function of this type is used to motivate the development.

Response characteristics of cylindrical piezometers

The finite difference solutions presented for the fundamental process of pore pressure equalization in a soil piezometer system are the first of their kind to be published for cyhndrical piezometers. The response-time relationships established for cylindrical piezometers (of radius a and length b) are of the same general form as those for spherical piezomelers, the exact shape of a particular relationship being a function of the ratio a/b, the soil compressibility m and the flexibility of the piezometer measuring system V. The soil-pierometer system characteristics can be best represented by a control parameter λ = 47πbm/V. The value of this parameter characterizes the shape of the response-time curve, for which there is a unique time ratio t90/t50 and time factor ratio T90/T50. On this basis, the cylindrical equalization chart is constructed, which provides a direct means for the analysis of equalization tests in cylindrical piezometers. Interpretation of laboratory tests on piezometers embedded in clay triaxial specimens shows that equalization tests can provide reliable in situ measurement of soil permeability and good estimations of coefficients of consolidation. Les solutions de différences finies présentiées relativement au processus fondamental de l'égalisation de la pression interstitielle dans un système sol-piézomètre sont les premières de ce type à être publiées en ce qui concerne les piézométres cylindriques. Les relations réponse-temps établises pour les piézomètres cylindriques (de rayon a et de longueur b) sont de la même forme générale que celles qui correspondent aux piézroméres sphériques, la forme exacte d'une relation donnéé étant fonction du rapport a/b, de la compressibilité du sol m et de la souplesse du système de mesure du piézomètre V. La meilleure façon de représenter les caractéristiques du système sol-piézomètre est de faire appel à un paramètre de contrôle λ = 4π2bm/V. La valeur de ce paramètre caractérise la forme de la courbe réponse-temps pour ladquelle il existe un rapport unique de temps t90/t50 et un rapport de facteur de temps T90/T50. L'abaque d'égalisation cylindrique est établi à partir de ces données; cetabaque permet d'analyser directement les essais d'égalisation dans le cas de piézomètres cylindriques. L'interprétation des résultats des essais en laboratoire de piézomètres fichés dans des échantillons triaxiaux d'argle montre que les essais d'égalisation sent capables de fournir des mesures in situ fables de la perméabilité du sol ainsi que de bonnes évaluations de coefficients de consolidation.

Pore pressure equalization of piezometers in compressible soils

This Paper examines the process of pore pressure equalization in soil piezometer systems which is governed by the shape factor F of the piezometer, the volume factor V of the measuring system, and the coefficients of permeability and consolidation k and c of the soil. Gibson (1963) obtained a theoretical solution for a spherical piezometer of radius a in a compressible soil in terms of the dimensionless parameter μ(= 4πa3 m/V) and T(= ct/a2), and this solution was used by the Authors to establish the response-time relationships for a wide range of μ values. These theoretical relationships were verified against those obtained by means of a finite difference method, which was also used for a brief examination of the transient distribution of pore pressure during the equalization process; the radius of influence was found to be a function of the parameter µ. On the basis of Gibson's theory, a greatly simplified procedure was devised for the inter-pretation of the equalization process to enable the soil properties k and c to be determined directly by the use of an Equalization Chart. An experimental programme of equalization tests was carried out on a range of piezometers of different shapes and sizes embedded in clay specimens and connected to a number of measuring systems of different volume factors. Interpretation of the test results by an Equalization Chart provided verification of Gibson's theory and illustrated the usefulness of equalization tests for in situ measurement of k and c. Cet article examine le processus d'étgalisation de la pression interstitielie dans des piézométres in situ, processus régi par le facteur de forme F du piézométre, le facteur de volume V du systéme de mesure et les coefficients de perméabilité et de consolidation k et c du sol. Gibson (1963) a obtenu une solution théorique pour un piézométre sphérique de rayon a dans un sol compressible, en fonction du paramétre adimensionnel μ(= 4πa3 m/V) et T(= ct/a2); cette solution a été utilisée par les auteurs pour établir les relations répose-temps pour une large gamme de valeurs μ. Ces relations theoriques ont été vérifiées avec les relations obtenues au moyen d'une méthode de différences finies qui également été utilisée pour un examen sommaire de la distribution transitoire de la pression interstitielle au tours du processus d'égalisation; les résultats ont montré que le rayon d'influence était unc fonction du paramétre μ. Sur la base de la théorie de Gibson. une méthode extrêmement simplifiée a été élaborée pour l'interprétation du processus d'égalisation pour permettre de déterminer les propriétés du sol k et c directement par le moyen d'un Diagramme d'Egalisation. Un programme expérimental d'essais d'égahsation a été réalisé; les essais portaient sur toute une gamme de piézométres de différentes formes et dimensions, encastrés dans des spécimens d'argile et relies a un certain nombre de systèmes de mesure de facteurs de volume différents. L'interprétation des résultats des essais, réalisée au moyen d'un Diagramme d'Egalisation, a permis de vérifier la théorie de Gibson et de démontrer l'utilité des essais d'égahsation pour la mesure in situ de k et c.