Prospective evaluation of complications in an endoscopy unit: use of the A/S/G/E quality care guidelines.

In 1989, the American Society for Gastrointestinal Endoscopy released a quality assurance monograph in which a procedure review process was outlined. The major elements of the program for quality assurance in gastrointestinal endoscopy included: (1) procedure reports, (2) an endoscopic unit record, and (3) a procedure review. This study was designed to use the procedure review process to determine the incidence of complications, to identify quality assurance issues, and to determine whether audits and/or studies would result from this process. To make a meaningful interpretation as to what constitutes an important complication, a classification to define potential problems was established. Using this classification, a complication was identified in 64 of 3287 procedures (1.9%). These complications were discussed in a monthly morbidity and mortality conference. Additionally, 21 quality assurance issues were identified that led to four studies addressing these quality assurance issues.     

Use of long catheters for multipatient anesthetic monitoring at high respiratory frequencies

Anesthetic gases from several patients can be monitored simultaneously with a centrally located mass spectrometer. Such monitoring requires catheters from patient to spectrometer that are several meters long. Scamman (J Clin Monit 1988;4:227–229) found that when the respiratory frequency is high, as with infants, the CO₂ signal from the patient is unacceptably distorted during passage down the catheter. This is due to Taylor dispersion of the input signal. An outline of the theory of Taylor dispersion is given. The equations describe the interaction between the velocity distribution (which, in laminar flow, is parabolic) and the radial diffusion of CO₂. This interaction keeps a tracer signal together in a pulse, as it moves down the tube with themean velocity, spreading somewhat as it proceeds. How much does an initially sharp signal become blurred? The spread of such a signal when it reaches the detector, measured in time, can be expressed in various ways. Measurement is complicated, however, by the fact that the gas pressure may fall by as much as a factor of 10 along the line. The resultant expansion and acceleration of the gas cannot be ignored. A full treatment of this complication is given elsewhere, but the following simple equation is described: {ie237-1} Typically, the spread time is up to a quarter of a second for catheters of 50 m, such as used by Scamman. This is comparable with the period of CO₂ rise and fall for infants and explains the serious distortion in wave form that Scamman found. Some distortion can be eliminated by reducing R to 0.1 or less, but the extent of this improvement is small. Ideally, for fast-breathing patients, the catheter length should be reduced to 20 m or less, if possible.     

Chemotherapy-induced nausea

The rubric complementary medicine covers a variety of approaches that may seem alike only in their being outside conventional care and training. We have asked experienced practitioners to present their own pieces of this jigsaw, realising that these clinical fragments, when seen together, create excitement but also confusion. Of course, this forum is not intended to be a comprehensive review of relevant complementary treatments, and often the individual apporaches to clinical problems will appear totally unrelated, while their apparent effectiveness stretches the biomedical model and conventional research methodology beyond their capacity. With this in mind, we intend that forthcoming articles and reviews will expand on the therapies themselves, and discuss the evidence supporting them.     

尿液有形成分镜检与自动化检测方法学利弊和互补分析

结合当前国内外尿液分析的发展现状和目前国内常规检验工作忽视尿有形成分检查的错误倾向,笔者参考国家(际)标准、文献及本人的临床实践、科研成果,阐述了尿液有形成分检查的临床价值、标准检验流程,评论了应用各种仪器进行镜检筛选的优点与不足,并对如何加强我国尿液分析的质最管理提出了见解.     

The severity of airways obstruction as a determinant of treatment response in COPD

Guidelines recommend that patients with COPD are stratified arbitrarily by baseline severity (FEV₁) to decide when to initiate combination treatment with a long-acting β₂-agonist and an inhaled corticosteroid. Assessment of baseline FEV₁ as a continuous variable may provide a more reliable prediction of treatment effects. Patients from a 1-year, parallel-group, randomized controlled trial comparing 50 μg salmeterol (Sal), 500 μg fluticasone propionate (FP), the combination (Sal/FP) and placebo, (bid), were categorized post hoc into FEV₁ <50% and FEV₁ ≥50% predicted subgroups (n=949/513 respectively). Treatment effects on clinical outcomes – lung function, exacerbations, health status, diary card symptoms, and adverse events – were investigated. Treatment responses based on a pre-specified analysis explored treatment differences by severity as a continuous variable. Lung function improved with active treatment irrespective of FEV₁; Sal/FP had greatest effect. This improvement appeared additive in milder disease; synergistic in severe disease. Active therapy significantly reduced exacerbation rate in patients with FEV₁ <50% predicted, not in milder disease. Health status and breathlessness improved with Sal/FP irrespective of baseline FEV₁; adverse events were similar across subgroups. The spirometric response to Sal/FP varied with baseline FEV₁, and clinical benefits were not restricted to patients with severe disease. These data have implications for COPD management decisions, suggesting that arbitrary stratifications of baseline severity are not necessarily indicative of treatment efficacy and that the benefits of assessing baseline severity as a continuous variable should be assessed in future trials.     

兔动静脉短路环法诱导组织工程骨支架材料血管生成的初步研究

Objective To compare the effects of 2 vascular carriers, arteriovenous loop and arteri-ovenous bundle, on inducing angiogenesis in coral scaffold of vascularized tissue-engineered bone in animal models.Methods Thirty-six adult male New Zealand rabbits were randomized into 2 even groups.In group A, an arteriovenous loop (AVL) was formed by microsurgical anastomosis at the proximal ends between the femoral poptiteal artery and vein, and placed in the circular side groove of the coral block (6 mm × 8 mm × 10 mm) .In group B, flow-through vessels bundles of both femoral artery and vein were placed in the side grooves of the coral block.All the implants in 2 groups were wrapped by a micro-porous expand-ed-polytetrafluoroethylene (ePTFE) membrane, and fixed subcutaneously by suturing.Evaluation methods included gross morphological observations, histological examinations, India ink perfusion and vascular casting after 2, 4, 6 weeks.The density of blood vessels was analyzed by the statistical software SPSS 10.0.Results All the corals were encased by newly formed fibrovascular tissues in 2 groups.Ink-stained vessels distributed the surfaces and side grooves, and invaded the interspaces of corals.The degree of vascularization increased over the course of experiment.Blood vessel density demonstrated a significant continuous increase between 2 and 6 weeks after implantation in group A.The mean value of blood vessel density in group A (2 weeks 276.60±4.67, 4 weeks 517.20±10.66, 6 weeks 707.00 ±11.87) was significantly higher than in group B (2 weeks 153.60 ±7.16, 4 weeks 269.40±6.80, 6 weeks 279.20±6.53) (P <0.01).Vascular casting showed that in group A, significant blood vessels sprouted from all areas of the loop, espe-cially at the entrance of the arteriovenous pediele where the small tubes were densely interconnected.In group B, however, no blood vessels sprouted from the arteriovenous bundles and only some small vessels grew from the entrance and exit.Conclusions A vascularized coral model can be constructed by inserting an ar-teriovenous loop or an arteriovenous bundle, useful in vascular bone tissue engineering.The former, however, have stronger abilities to induce angiogenesis than the latter.