Early wound irrigation improves the ability to remove bacteria

BACKGROUND: Although most surgeons prefer to treat contaminated wounds as soon as possible, the effect of timing on the ability of irrigation to reduce the amount of bacteria in a wound is not fully known. We evaluated the effect of different delays in irrigation on bacterial removal in an animal model. METHODS: A complex musculoskeletal wound was created in the proximal part of the leg of goats. The wound was contaminated with Pseudomonas aeruginosa (lux) bacteria, genetically modified to emit photons, in order to allow for quantitative analysis of bacterial concentration with a photon-counting camera system. The contaminated wounds were closed, and wound irrigation was performed with 6 L of normal saline solution by means of pulsatile lavage after the assigned time-intervals of three, six, and twelve hours. Images were made before and after treatment. Relative luminescent units and clearance ratios were obtained and calculated for each wound. RESULTS: Earlier wound irrigation resulted in superior bacterial removal in our model. Irrigation resulted in a 70% +/- 2%, 52% +/- 3%, and 37% +/- 4% reduction in bacterial counts from the pre-irrigation level at three, six, and twelve hours, respectively. The clearance ratios were significantly different at all time-points (p < 0.004). CONCLUSIONS: Earlier irrigation in our contaminated wound model resulted in superior bacterial removal.     

Effects of surface irrigation on the thermal response of tissue during laser irradiation

Effects of surface irrigation on the thermal response of tissue during laser irradiation are investigated. In particular, influence of temperature and flow rate of the irrigation fluid on the resulting temperature distributions and coagulation depths are studied. Intraluminal Nd:YAG laser irradiation of bovine muscle is performed in vitro for a fixed value of the irrigation flow rate while the irrigation temperature is varied, and for a fixed irrigation temperature while the irrigation flow rate is kept constant. Thermocouples are used to measure the temperatures within the tissue for various irradiation and irrigation conditions. Higher temperatures and deeper coagulation depths are achieved as the temperature of the irrigation fluid is increased. For sufficiently low values of irradiance and exposure time, the use of cold irrigation is shown to prevent or delay tissue carbonization. Beyond a critical irradiance and an exposure time, use of cold irrigation does not prevent tissue carbonization. Coagulation depths and temperature distributions are not affected by a change in the flow rate of laminar irrigation. Application of stagnant irrigation, however, results in an increase in coagulation depth. Results of this study suggest that the dominating mechanism of heat transfer during application of laminar irrigation is thermal diffusion as compared to the bulk motion of the fluid. © 1994 wiley-Liss, Inc.     

Vaccines based on the cell surface carbohydrates of pathogenic bacteria

Glycoconjugate vaccines, in which a cell surface carbohydrate from a micro-organism is covalently attached to an appropriate carrier protein are proving to be the most effective means to generate protective immune responses to prevent a wide range of diseases. The technology appears to be generic and applicable to a wide range of pathogens, as long as antibodies against surface carbohydrates help protect against infection. Three such vaccines, against Haemophilus influenzae type b, Neisseria meningitidis Group C and seven serotypes of Streptococcus pneumoniae, have already been licensed and many others are in development. This article discusses the rationale for the development and use of glycoconjugate vaccines, the mechanisms by which they elicit T cell-dependent immune responses and the implications of this for vaccine development, the role of physicochemical methods in the characterisation and quality control of these vaccines, and the novel products which are under development.     

Removal of pheochromocytoma by enucleation

In 6 cases pheochromocytomas were removed by enucleation. A typical case is reported in detail illustrating that it might be a procedure of choice in avoiding the risk of injuring the great vessels during operation.     

Removal of Phosphorus by Hemodialysis

The control of serum phosphorus by dialysis is made difficult by the fact that intradialytic blood levels tend to be low, and because phosphorus is removed almost exclusively from the plasma during its passage through the dialyzer. The most practical way to increase phosphorus removal is to extend dialysis time, although attention to dialysis efficiency (surface area, advanced membrane, and higher blood and dialysate flow rates) also plays a role. Benefits of hemodiafiltration in helping control serum phosphorus have been claimed, but not found in all studies. Because serum phosphorus levels tend to plateau during the later parts of a dialysis session, extending weekly dialysis time is of greater benefit for phosphorus removal than for urea removal. Increasing dialysis frequency also probably has a small benefit. It appears that 18–30 hours of dialysis per week are required to obviate the need for phosphorus binders. Several promising models of phosphorus kinetics are under development. These may help predict the change in treatment on serum phosphorus levels, but their ability to do so has not yet been critically assessed.     

葡萄糖溶液冲洗剥离面止血在腹腔镜保守治疗输卵管妊娠的价值

目的探讨5%葡萄糖液冲洗输卵管妊娠剥离面止血在腹腔镜保守治疗输卵管妊娠的临床应用价值. 方法比较葡萄糖液冲洗输卵管妊娠剥离面止血(观察组)与单极电凝止血(对照组)各43例中保留输卵管失败的例数、术后内出血、持续妊娠、患侧输卵管再次妊娠和正常宫内妊娠等临床指标. 结果保留输卵管失败对照组(10/43,23%)高于观察组(0/43)(χ2＝11.316,P=0.001);患侧输卵管再次妊娠对照组(2/34,6%)与观察组(0/34)无差异(P＝0.175).两组均无术后腹腔内出血和持续妊娠.正常宫内妊娠率观察组44.1%(15/34),对照组40.0%(10/25),两组差异无显著性(χ2＝0.100,P=0.752). 结论用5%葡萄糖液冲洗输卵管妊娠剥离面止血方法优于电凝法.     

A new instrument for surface suction and removal of irrigation fluid during surgery

A new instrument for removal of intraocular/extraocular irrigating solutions during eye surgery, based on modification of a miniature otologic suction device, is now commercially available.     

洗胃机术中结肠灌洗治疗左半结肠癌急性梗阻

目的 探索用洗胃机作术中结肠灌洗行左半结肠癌急性梗阻一期切除吻合的方法和作用。方法 从阑尾腔内置入导尿管连接到洗胃机的输出口上，压力保持在０．０４Ｍｐａ进行连续结肠灌洗和消毒。结果 ２５例左半结肠癌急性梗阻特术中结肠灌洗，一期切除吻合术，无吻合口瘘，无手术死亡，切口感染５例经换药后治愈。结论 术中应用洗胃机结肠灌洗和消毒的方法，达到了省时省力、肠道清洁干净的效果。只要手术适应证掌握得当，吻合方法正     

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人类的肠道菌群极为复杂 ,在胃肠道的不同部位有不同的菌群聚集。食物中正常含有大量的细菌 ,但大部分的细菌对于粘膜表面没有粘附能力。在过去的 2 0年中 ,大量的研究集中在细菌易位以及易位过程中细菌的作用[1～ 4] ,而对于正常菌群的保护作用、粘膜的功能以及局部粘膜的保护系统作为一个整体研究得比较少。越来越多的证据表明 ,功能完好的正常菌群以及正常的粘膜保护作用不仅可以防止细菌感染 ,而且对于炎症、溃疡、变态反应以及肿瘤性疾病具有重要的作用。1　表面保护系统一个功能完整的表面保护系统 (ｓｕｒｆａｃｅｐｒｏｔｅｃｔｉｏ…     

Removal of gadolinium by peritoneal dialysis

An association between gadolinium-containing contrast and the development of nephrogenic systemic fibrosis (NSF) has been increasingly recognized. For patients receiving hemodialysis (HD) who are exposed to gadolinium, the Federal Drug Administration (FDA) recommends HD to remove this contrast agent in order to minimize the risk of NSF. This study examines if gadolinium can be removed by frequent exchanges by peritoneal dialysis (PD). Following administration of 0.1 mmol/kg of gadodiamide to a patient with end-stage renal disease, the serum clearance of this contrast agent by automated PD was examined. 10 and 15 exchanges of PD using an automated cycler were respectively performed during the first and second 24-hour periods after gadolinium exposure. Serum gadolinium levels were measured 1 hour after the gadolinium administration, then at 24 and 48 hours after PD was initiated. 90% of the gadolinium was removed from the circulation in 2 days with a regimen of 10-15 exchanges per day of PD. For patients on chronic maintenance PD who receive gadolinium, our case suggests that a temporary intensive automated PD regimen, aimed at maximizing clearance of this contrast agent immediately after exposure, could be an effective alternative when institution of HD is problematic.     

Removal of P-cresol sulfate by hemodialysis

Protein-bound solutes are poorly cleared by dialysis. Among the most extensively studied of these solutes is p-cresol, which has been shown to be toxic in vitro. This study examined the form in which p-cresol circulates and quantified its removal by hemodialysis. HPLC analysis of plasma from hemodialysis patients contained a peak whose mobility corresponded to synthetic p-cresol sulfate (PCS) but no detectable unconjugated p-cresol. Treatment with sulfatase resulted in recovery of this peak as p-cresol, confirming its identity. Subsequent studies compared the removal of PCS and another protein-bound solute, indican, to the removal of urea during clinical hemodialysis treatments. PCS and indican were 94 +/- 1% and 93 +/- 2% bound to plasma protein, respectively. Protein-binding caused a predictable decrease in measured dialytic clearance, which averaged 20 +/- 4 ml/min for PCS and 25 +/- 5 ml/min for indican as compared with 260 +/- 20 ml/min for urea. Volumes of distribution for the protein-bound solutes were greater than the plasma volume, averaging 15 +/- 7 L for PCS and 14 +/- 3 L for indican as compared with 37 +/- 7 for urea. Solute reduction ratios were 20 +/- 9% for PCS, 30 +/- 7% for indican, and 69 +/- 5% for urea. We conclude that p-cresol circulates in the form of its sulfate conjugate, PCS. PCS is poorly removed by hemodialysis because its clearance is limited by protein binding and the ratio of its volume of distribution to its clearance is high.     

Influence of surface sub-micropattern on the adhesion of pioneer bacteria on metals

Abstract:  Most of the implantable medical devices are prone to infection caused by microorganisms that form biofilms. Pseudomonads are frequently used as model species for studying bacterial adhesion. The initial stages of biofilm formation are influenced by different factors including, among others, the chemistry of the surface, the roughness, and topography. The aim of this work was to assess the early stages of Pseudomonas fluorescens biofilm formation on sub-microstructured surfaces (SMS) that are in tune with bacterial size. Copper and gold were used as the substrata. It was concluded that SMS influenced bacterial length, alignment, and distribution, whereas the chemistry of the surfaces affected bacterial length and distribution. However, the effect of the SMS was the most significant. The shape of the bacterial colonies and the polymeric substances production were also influenced by SMS and the chemistry of the surface and both factors may be considered to reduce the susceptibility of a surface to biofilm formation.     

持续滴注法治疗再造耳感染

目的介绍应用持续滴注法治疗再造耳感染的方法。方法取再造耳感染腔隙内的分泌物做细菌培养和药敏试验。在埋置再造耳郭支架的腔隙内放置2根引流管;引流管剪侧孔以利于滴注液流到腔隙内和收集流经腔隙的引流液。将生理盐水通过2个引流管对感染的软骨支架进行持续滴注。根据药物敏感试验结果行抗生素盐水滴注。经1周滴注后,先关闭上引流管12 h,抽取下引流管内的分泌物做细菌培养;结果示无细菌生长时拔出引流管,封闭腔隙。结果本组3例患者经持续滴注后控制了腔隙内感染,2例保住了再造耳支架,1例保住了耳后皮肤的完整性,避免了再造耳手术失败。结论持续滴注法能够有效控制再造耳感染,且可挽救被感染的再造耳。