Detection of preanalytical errors in arterial blood gas analysis

IntroductionBlood gas analysis (BGA) is an essential test used for years to provide vital information in critically ill patients. However, the instability of the blood gases is a problem. We aimed to evaluate time and temperature effects on blood gas stability.Materials and methodsArterial blood was collected from 20 patients into syringes. Following BGA for baseline, syringes were divided into groups to stand at 4°C and 22°C for 30, 60, 90, 120 minutes. All were tested for pH, partial pressure of carbon dioxide (pCO₂), partial pressure of oxygen (pO₂), oxygen saturation (sO₂), oxyhemoglobin (O₂Hb), sodium, potassium, glucose, lactate, oxygen tension at 50% hemoglobin saturation (p50), and bicarbonate. A subgroup analysis was performed to detect the effect of air on results during storage. Percentage deviations were calculated and compared against the preset quality specifications for allowable total error.ResultsAt 4°C, pO₂ was the least stable parameter. At 22°C, pO₂ remained stable for 120 min, pH and glucose for 90 min, lactate and pCO₂ for 60 min. Glucose and lactate were stable when chilled. Air bubbles interfered pO₂ regardless of temperatures, whereas pCO₂ increased significantly at 22°C after 30 min, and pH decreased after 90 min. Bicarbonate, sO₂, O₂Hb, sodium, and potassium were the unaffected parameters.ConclusionsCorrect BGA results are essential, and arterial sample is precious. Therefore, if immediate analysis cannot be performed, up to one hour, syringes stored at room temperature will give reliable results when care is taken to minimize air within the blood gas specimen.     

College course scarcity and time to degree

College students are taking longer to earn baccalaureate degrees now than ever before, but little is known about institutional factors that may contribute to this trend. In this paper we investigate an important institutional constraint—course scarcity—that we hypothesize may be associated with increased time to degree. We employ a unique administrative dataset from a large, moderately selective, public institution and use an instrumental variables approach, identifying off the random registration times assigned to students. Results suggest that course scarcity does not delay students’ graduation. We explore alternative explanations for our findings and discuss a variety of other factors correlated with time to baccalaureate completion.     

Does working during higher education affect students’ academic progression?

This paper examines the effect of working during higher education on academic progression, in terms of number of credits acquired by first-year university students in Italy. We discuss different contrasting hypotheses on the role of employment during university on academic outcomes: the zero-sum perspective, the reconciliation thesis, the positive and the negative selection to work hypotheses. In the empirical part we analyze data from the Eurostudent survey, which collected data on a representative sample of university students who were enrolled in the academic year 2002/03, after the implementation of the ‘Bologna Process’. We use a negative binomial regression model considering work experience as an endogenous multinomial treatment. Results indicate that, conditional on observed covariates (socio-demographic variables, school-related and university-related variables), there is a positive self-selection into employment, especially for low-intensity work. Traditional multivariate regressions show a penalty in academic progression only for high-intensity workers, but once accounted for unobserved heterogeneity also the low-intensity work experience appears to negatively affect academic progression.     

A multi-criteria approach for the group assessment of an academic course: A case study

The present paper aims at proposing a structured methodology to evaluate the results of an academic training course addressed to postgraduate students. The evaluation process intends to identify the efficacy of an education course by means of a comparison between the general objectives and the results expected by the students. Since the evaluated aspects by the students, detected by means of questionnaires, are both quantitative and qualitative, the proposed methodology is based on the analytic hierarchy process (AHP). In order to facilitate the evaluation process, answers have been modelled by means of linguistic variables. In particular, different evaluation scales have been used and each one is characterized by different levels associated to different fuzzy numbers.     

《古今图书集成》的编排体例--以《博物汇编·草木典·桃部》为例

《古今图书集成》的内容复杂广博,如果没有合理科学的编排不可能成为备受赞誉的大型工具书,它开创的由“汇编”到“典”再到“部”的分类方法层次清晰,逻辑严密,便于查找使用。“部”下的“汇考”“艺文”“纪事”“杂录”“外编”是编者根据材料的性质分别归类的,即使相同的内容也可以归入不同的类别,反映出编者对文献资料多角度、多层面的认识。《古今图书集成》的每项专题都可视为一部专门性类书,对有关研究具有索引作用,这是其科学的编排所产生的内容集成之外的价值。     

最优购书量的讨论

运用概率论和微分学的知识,讨论在一定的广告费用和书本贮存费用的情况下,根据图书的购进价和售出价确定书店的最优购书量．     

古文英译的历程和前景

古文英译是翻译事业的组成部分。回顾古文英译的历程、总结经验、展望未来 ,以期有助于中西文化的交流和中西外事的交往。     

区域经济协调：西部基础设施建设中值得注意的问题

西部基础设施建设是一个系统工程,是西部经济发展的物质条件,也是全国经济和社会发展总系统的重要组成部分,各区域协调发展,任重道远。西部基础设施建设必须注意以下几方面的协调:科学规划,统筹协调;区域开发与突出重点协调;基础设施建设与非基础设施建设协调;基础设施建设与生态保护协调;城市基础设施建设与农村基础设施建设协调。     

开发具有E-Mail功能的VB应用程序

面对企业和单位对个性化电子信息传递的需要,探讨利用VB编程实现的一种方法.     

多媒体计算机网络对作文教学的影响

多媒体计算机网络技术的应用,导致作文教学的思想观念、教学方法和教学设计的深刻变革.教师利用多媒体计算机网络的资源共享、交互和多媒体功能,可以改进教学方法,突破传统作文教学的某些弊病.