The PB3300 intraarterial blood gas monitoring system

Continuous intraarterial blood gas (IABG) monitoring is in clinical use both in the operating room and intensive care unit. This technology uses miniature, optically-based sensors that can be placed into a patient's artery. The arterial blood gas values are transduced into an optical signal that is measured by a bedside monitor on which the values are displayed. In this paper, we describe the operating principles of the PB3300 Intra-Arterial Blood Gas Monitoring System (Puritan-Bennett Corporation, FOxS Division, Carlsbad, CA). Topics include the principles of fluorescent determinations of pH,PCo ₂, andPO ₂; the optical path of the PB3300; system calibration; dye layer geometry; and clinical operation. The accuracy, precision, and drift of the system measuring tonometered aqueous standards are reported. The following values were noted for eight sensors sending data to eight monitors: system bias and precisions of 0.00±0.02 pH at a pH of 7.40, –2.5±1.5 mm HgPCo ₂ at aPCo ₂ of 40 mm Hg, and 3.3±1.3 mm HgPO ₂ at aPO ₂ of 80 mm Hg.

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Abstrakt Die kontinuierliche intraarterielle Blutgasüberwachung (IABG) wird klinisch sowohl im OP als auch auf der Intensivstation eingesetzt. Hierbei werden miniaturisierte, optische Sensoren angewandt, die sich direkt in der Arterie des Patienten plazieren lassen. Die Blutgaswerte werden in optische Signale umgesetzt und von einem bettseitigen Monitor gemessen und angezeigt. In dieser Arbeit beschreiben wir das Funktionsprinzip des Intra-Arteriellen Blutgasanalysesystems PB3300 (Puritan-Bennett Corporation, FOxS Division, Carlsbad, CA). Themen sind die Grundlagen der Bestimmung von pH, PCO2 und PO2 mittels Fluoreszenz; die optische Übertragung des PB3300; die Kalibrierung des Systems; die Geometrie der Farbschichten und der Einsatz in der Klinik. Die Genauigkeit, Auflösung und Drift des Systems bei der Messung von tonometrischen wässrigen Standards wird beschrieben. Die folgenden Werte ergaben sich aus einer Meßreihe mit 8 Sensoren, die an 8 Monitore angeschlossen waren (jeweils Bias, Streuung und Sollwert): 0.00±0.02 pH bei 7.40 pH, –2.5±1.5 mmHg PCO2 bei 40 mmHg PCO2 und 3.3±1.3 mmHg PO2 bei 80 mmHg PO2.

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Resumen La monitorizaciòn continua de gases intraarteriales tiene uso clinico, tanto en el pabellòn de operaciones como en la unidad de cuidados intensivos. Esta tecnologia utiliza sensores miniatura de tipo òptico que pueden ser introducidos en una arteria del paciente. Los valores de gases arteriales son transducidos en forma de señal òptica que es medida al lado de la cama del paciente por un monitor que presenta los valores numéricos. En este trabajo, describimos los principios de operaciòn del PB3300 Intra-Arterial Blood Gas Monitoring System (Puritan-Bennett Corporation, FOxS Division, Carlsbad, CA). Los temas incluyen los principios de determinaciones fluorescentes de pH, PCO₂, and PO₂; la via òptica del PB3300; calibraciòn del sistema; geometria de la capa de colorante; y la operaciòn clinica. Se presentan la exactitud, precisiòn, y deriva (drift) del sistema, midiendo soluciones acuosas de tonometrìa estàndar. Los siguientes valores fueron registrados para ocho sensores enviando informaciòn a ocho monitores: los sesgos del sistema y las precisiones fueron de 0.00±0.02 pH a pH 7.40, –2.5±1.5 mmHg PCO₂ a PCO₂ 40 mmHg, y 3.3±1.3 mmHg PO₂ a PO₂ 80 mmHg.

     

Pre-B cells and other possible precursor lymphoid cell lines derived from patients with X-linked agammaglobulinemia

A group of unique Epstein-Barr virus-containing cell lines was derived from the bone marrow of three patients with X-linked agammaglobulinemia. Efforts to obtain cell lines from the peripheral blood of these patients were uniformly unsuccessful. Immunofluorescence analyses as well as biosynthetic studies with [(35)S]methionine indicated unusual patterns of Ig synthesis in many of these bone marrow derived lines. Seven of the lines were of particular interest in that two produced no Ig of any type; two others showed no Ig by fluorescence but small amounts by [(35)S]methionine labeling; one expressed only cytoplasmic μ chains without any evidence of light chain synthesis, and two produced primarily μ chains with only slight amounts of light chains. One of the lines without membrane or cytoplasmic Ig studied in detail grew like a typical lymphoid line and was carried in intermittent culture over a period of 2 yr without Ig expression. One line grew quite differently and resembled the round cell type described previously, which has been obtained from a variety of sources. The cell line with cytoplasmic μ chains and no light-chain expression had the characteristic properties of pre-B cells. Three normal type Ig-producing cell lines also were obtained from the patients. The accumulated evidence obtained in the present study indicates that these unusual cell lines represent normal precursor cells of the B-cell lineage; these grew out in these cases because of the virtual absence of mature B cells that ordinarily overgrow the culture system. However, the possibility that in certain instances they reflect abnormal Ig synthesis characteristic of the disease has not been ruled out.     

Radiation-induced red cell damage: role of reactive oxygen species

BACKGROUND: Cellular blood components are irradiated to prevent graft- versus-host disease in transfusion recipients at risk for this syndrome. Because gamma radiation can result in the production of reactive oxygen species, the role of reactive oxygen species was investigated in radiation-induced red cell damage. STUDY DESIGN AND METHODS: Whole blood from normal donors was exposed to various doses of t-butyl hydroperoxide (0-1 mM) and/or to gamma-radiation (0-50 Gy). Oxidative damage was assessed by the extent of lipid peroxidation (measured by thiobarbituric acid-reactive substances [TBARS]) and hemoglobin oxidation. Fresh blood was divided into three parts-one initially irradiated and stored, another stored with portions irradiated weekly, and a third stored without irradiation. TBARS and hemoglobin oxidation were measured weekly. RESULTS: As expected, t- butyl hydroperoxide induced TBARS formation and hemoglobin oxidation in a dose-dependent fashion. The gamma-radiation not only increased hemoglobin oxidation and TBARS formation, but also enhanced the t-butyl hydroperoxide effect on red cells. Red cell storage increased TBARS generation and hemoglobin oxidation in a time-dependent fashion. When radiation was administered either initially or after weekly storage, TBARS production and hemoglobin oxidation were increased over that measured in unirradiated paired controls. CONCLUSION: Gamma radiation at clinically used doses increases lipid peroxidation and hemoglobin oxidation in human red cells. The effect of gamma-radiation is accentuated by blood storage and induces damage independent of time of storage.     

上海市0～6岁小儿佝偻病的现状调查

目的:了解上海市小儿佝偻病的现状及影响因素。方法:2005年春季以整群和分层随机抽样法抽取上海市部分城区0～6岁小儿821名,采取问卷调查方法了解小儿的生活环境、饮食习惯、户外活动、营养状况、既往疾病史及母亲的妊娠情况等。佝偻病的诊断以1996年国家卫生部颁布的"婴幼儿佝偻病防治方案"为诊断标准。结果:取得完整有效资料769名,其中男童396名,女童373名;集居儿童456名,散居儿童313名。①小儿佝偻病患病率为17.3%(133/769),其中男童患病率为17.4%、女童为17.2%。②佝偻病与喂养方式(母乳喂养的患病率为13.0%、混合喂养的患病率为17.5%、人工喂养的患病率为25.2%)、鱼肝油添加(按时添加维生素D的患病率为13.5%、偶加或未加维生素D的患病率为32.5%)、居住环境(居住在市区的患病率为23.6%、居住在郊区的患病率为10.6%;集居儿童患病率为13.8%、散居儿童患病率为22.4%)、户外活动时间(经常户外活动的患病率为12.9%、偶尔户外活动的患病率为31.8%)、反复呼吸道感染(小儿有反复呼吸道感染的患病率为26.9%、无反复呼吸道感染的患病率为12.9%)、母孕期缺钙(母孕期有缺钙的患病率为33.2%、无缺钙的患病率为12.0%)等因素有关(P<0.01)。结论:上海市小儿佝偻病患病率有上升趋势。影响因素与城市环境污染、母乳喂养减少、年轻父母科学育儿知识缺乏等有关。     

ALLERGEN AVOIDANCE IN THE PRIMARY PREVENTION OF ATOPY

SUMMARY Atopy development cannot yet be predicted with certainty, and primary prophylaxis has to be directed at every ‘at-risk’ infant. However, substantial progress has been made in identifying environmental factors associated with allergic disorders. The process of sensitisation to common allergens may begin in utero. The influence of adjuvants, especially passive smoking, is considerable in individuals with established atopic disease. This article examines the role of intervention during pregnancy and the first year of life in the primary prevention of atopy and suggests a number of measures based on the current evidence.     

颈动脉内中膜厚度与初诊2型糖尿病视网膜病变的关系

目的:研究发现,糖尿病视网膜病变和动脉粥样硬化终点事件相关。试验拟验证颈动脉内中膜厚度与初诊汉族2型糖尿病患者糖尿病视网膜病变相关危险因素的关系。方法:①试验对象:选择2006-06/2007-06本院住院的初诊2型糖尿病患者187例,男114例,女73例;平均年龄(51±14)岁;平均体质量指数(24.7±4.7)kg/m2。均符合1997年美国糖尿病协会的2型糖尿病诊断标准,排除既往已存在心血管疾病者。患者对治疗及试验均知情同意。根据眼底照相检查结果,将所有受检者分为糖尿病视网膜病变组及非糖尿病视网膜病变组进行统计分析。②试验方法及评估:所有患者询问一般情况,测量颈动脉内中膜厚度以及相关生化指标,对糖尿病视网膜病变相关因素进行单因素及多因素Logistic回归分析。结果:纳入2型糖尿病患者187例,均进入结果分析。单因素Logistic回归分析显示,高血压、糖尿病家族史、颈动脉内中膜厚度、尿白蛋白、低密度脂蛋白胆固醇与糖尿病视网膜病变发生呈显著正相关,多因素Logistic回归分析未见显效因素。结论:单因素回归分析中颈动脉内中膜厚度及其他4项指标与糖尿病视网膜病变相关,而多因素回归分析这些因素未进入主效基因模型。     

Red cell loss following orthopedic surgery: the case against postoperative blood salvage

BACKGROUND: Expensive devices have been developed for the collection and transfusion of blood salvaged after hip or knee arthroplasty. STUDY DESIGN AND METHODS: The volume of salvaged red cells was measured for the first 6 hours after operation. This volume was compared to total red cell loss during hospitalization and to the volume of allogeneic red cells transfused. RESULTS: Mean postoperative red cell loss in 31 patients following hip replacement was 55 +/− 29 mL and that in 20 patients following knee replacement was 121 +/− 50 mL. The 6-hour wound drainage represented 8.7 and 16.8 percent of overall red cell loss during hospitalization for hip and knee replacement, respectively. The transfusion of postoperatively salvaged red cells would have supplanted transfusion of less than one-third of a unit of allogenic blood after hip replacement and two-thirds of a unit after knee replacement. Only three patients (5.9%) lost red cell volume in the drainage equivalent to or in excess of 1 unit of red cells (180 mL). The volume of red cells salvaged postoperatively bore no relationship to perioperative red cell losses as a whole. CONCLUSION: The relatively small red cell loss in the postoperative period in most arthroplasty patients does not appear to justify the routine use of this technique for the recovery of autologous blood.