重症病人的贫血和红细胞输注

简介 重症病人的定义并不是很明确,但大多数临床医生指的重症病人是那些伴有器官衰竭的急性病人。在英国,伴有多器官衰竭的病人在ICU(重症监护室)医治。贫血是重症病人的常见并发症。在ICU内,对贫血的治疗是输注异体红细胞。除禁止输血治疗的病人外,进入ICU的患者大概有40％接受过红细胞输注。输血实际操作过程中存在的多种不确定因素,直接关系到输血的安全性、有效性及输血指征。本文集中讨论以下三方面的问题:     

Homeopathy – what are the active ingredients? An exploratory study using the UK Medical Research Council's framework for the evaluation of complex interventions

Background  

Research in homeopathy has traditionally addressed itself to defining the effectiveness of homeopathic potencies in comparison to placebo medication. There is now increasing awareness that the homeopathic consultation is in itself a therapeutic intervention working independently or synergistically with the prescribed remedy. Our objective was to identify and evalute potential "active ingredients" of the homeopathic approach as a whole, in a prospective formal case series, which draws on actual consultation data, and is based on the MRC framework for the evaluation of complex interventions.     

Delivery Challenges for Fluoride,Chlorhexidine and Xylitol

The progression or reversal of dental caries is determined by the balance between pathological and protective factors. It is well established that a) fluoride inhibits demineralization and enhances remineralization, b) chlorhexidine reduces the cariogenic bacterial challenge, and c) xylitol is non-cariogenic and has antibacterial properties. The challenge that we face is how best to deliver these anti-caries entities at true therapeutic levels, over time, to favorably tip the caries balance. High caries risk people, including children with Early Childhood Caries (ECC), are a special challenge, since high cariogenic bacterial activity can override fluoride therapy. Current fluoride and chlorhexidine varnishes deliver all their activity within about 24 hours. Early studies with experimental slow release fluoride devices retained elevated levels of fluoride for months in a therapeutic range but have not been pursued. Preventive dentistry has largely ignored the benefits of reducing the bacterial challenge, partially due to primitive and inadequate delivery systems. For example, Chlorhexidine applied as a rinse partially reduces some bacteria but not others that are hiding within the biofilm. Better antibacterials and better delivery systems are needed. Xylitol delivered by gum or lozenge appears to be effective clinically in reducing cariogenic bacteria and caries levels, but novel systems that deliver therapeutic amounts when needed would be a major advance, especially for young children. Reducing the cariogenic bacterial challenge and enhancing the effect of fluoride by the use of new sustained-delivery systems would have a major effect on dealing with caries as a disease.     

Metrizamide computed tomography cisternography: pediatric applications

The methodology and clinical use of metrizamide (Amipaque) computed tomography (CT) cisternography are described as applied in the cases of 22 children with morphologic and physiologic abnormalities affecting the cranial portion portion of the central nervous system. In contrast to pneumoencephalography, CT cisternography affords equivalent or superior visualization of the basal cranal subarachnoid spaces with simpler technique and low morbidity. Intrathecal metrizamide enchancement in children causes a very low incidence of side effects.     

Cervical Castleman disease: CT study with angiographic correlation

The computed tomographic (CT) appearance, angiographic appearance, and clinical features of a patient with cervical Castleman disease, an uncommon disease of benign lymph node hyperplasia, are reported. CT scans showed a densely enhancing cervical mass. On external carotid angiography, the mass was seen as hypervascular with a capillary blush. Differential diagnosis included carotid body chemodectoma, vagal neuroma, tumor of the salivary gland, tuberculous adenitis and other granulomatous diseases, inflammatory lymph nodes, metastatic disease, and lymphoma.     

Quantitative digital subtraction angiography: two scanning techniques for correction of scattered radiation and veiling glare. Work in progress

Scattered radiation and veiling glare in digital subtraction angiography degrade contrast signals in a nonlinear and nonuniform way. This effect prohibits direct use of image data for accurate iodine measurement or energy subtraction imaging. Two techniques based on the use of scanning lead bars were proposed to measure the spatial distribution of scattered radiation and veiling glare in the unprocessed image data. With either technique, signals behind the lead bars were used to estimate the scatter-glare component and remove it from the image data. The scanning-lead-bar techniques can be used to reduce the scatter-glare component by a factor of up to 10. The scatter-glare correction leads to the recovery of degraded contrast signals and achieves reasonable linearity, uniformity, and consistency in the contrast measurement.