几种抗绿脓杆菌药物疗效筛选的实验研究

采用大鼠ＴＢＳＡ１５％Ⅲ度烧伤模型，伤后创面涂绿脓杆菌（１０~９／ｍｌ）后共分６组。其中５个组的创面分别涂以不同药物，对照组不涂药。通过对各组创面外观、痂下细菌定量与病理组织学观察，皆证实ＡｇＳＤ－ＺｎＳＤ－Ａ霜组效果最好，是满意的烧伤外用药。     

几种抗绿脓杆菌药物疗效筛选的实验研究

采用大鼠ＴＢＳＡ１５％Ⅲ度烧伤模型，伤后创面涂绿脓杆菌后共分６组。其中５个组的创面分别涂以不同药物，对照组不涂药。通过对各组创面外观、痂下细菌定量与病理组织学观察，皆证实ＡｇＳＤ－ＺｎＳＤ－Ａ霜组效果最好，是满意的烧伤外用药。     

几种抗凝药物预防损伤后小动脉血栓形成的实验研究

目的观察利伐沙班、氯吡格雷、依诺肝素钠等几种抗凝药物预防损伤后小动脉血栓形成的效果。方法损伤大鼠股动脉制作血栓模型,将大鼠分5组：a组：术前至术后1周,每日1次依诺肝素钠注射;b组：术前至术后1周,每日1次利伐沙班灌胃;c组：术前至术后1周,每日1次氯吡格雷灌胃;d组（肝素对照组）：术前至术后1周,每日2次注射肝素;e组（空白对照组）：术前至术后1周,每日1次注射等容量生理盐水。术后2h及1周检查吻合口通畅情况,术后1周测定大鼠血浆活化的部分凝血活酶时间（APTT）和凝血酶原时间（PT）。结果a、b、c、d组各时间点的吻合12I通畅率比e组均有非常显著性的提高,但其中c组较低,差异均有统计学意义,a、b、d组基本相同,差异无统计学意义;a组切口皮下出现张力性血肿1处,d组切口皮下出现张力性血肿4处,其他组未出现血肿;d组术后1周A阿T、PT较其它4组延长,与空白对照组及c组相比差异性有显著性意义（P〈0．05）,a、b、c三组问及其与对照组相比APlT、PT差异无统计学意义（P〉0．05）。结论利伐沙班、氯吡格雷、依诺肝素钠等抗凝药物在不增加出血倾向的前提下能预防损伤小动脉吻合口的血栓形成,氯毗格雷相对利伐沙班、依诺肝素抗凝效果较差,其中利伐沙班仅须每日1次口服给药,使用方便,依从性、耐受性更好,可作为显微外科抗凝用药的理想选择。     

几种抗菌药物对小鼠上皮生长的影响

应用新生小鼠皮块培养法，检测了五种烧伤局部常用抗菌药物，对上皮扩展的影响。结果表明０．０１５％－１％氯霉素、０．１２５％－１％磺胺嘧啶锌以及０．１２５％－１．０％的磺胺嘧啶银对小鼠上皮扩展均有明显抑制作用，浓度越高影响越大。１万单位％庆大霉素、２．５万单位％多粘菌素对上皮扩展无影响，超过这一浓度则有抑制作用。此结果提示对烧伤创面外用抗菌药物时应注意其对上皮生长扩展的影响，浓度不能太高。     

抗生素治疗大鼠烧伤绿脓杆菌菌血症时释放内毒素的实验研究

目的 观察不同种类抗生素治疗烧伤绿脓杆菌(PA103)菌血症时诱导细菌释放内毒素的情况。方法利用内毒素微量检测技术,检测抗生素治疗烧伤菌血症大鼠血中内毒素水平及血中细菌菌量。结果 应用敏感抗生素治疗烧伤菌血症均能有效杀灭细菌,但同时能不同程度诱导细菌释放内毒素,伊米配能诱导释放内毒素较少,头孢哌酮次之,头孢他啶和头孢氨噻肟较多。结论 不同种类抗生素具有不同程度的诱导绿脓杆菌释放内毒素的作用,释放的量与其杀菌能力无相关。     

烧伤创面外用药三期临床研究的原则(草案供讨论)

编者按 :当前 ,国内自行研制的烧伤创面外用药甚多 ,如何正确评价其疗效和毒副作用等 ,需要一些指导性原则。中华医学会烧伤外科学分会特委托孙永华、许伟石、付小兵 3位教授初拟一个草案 ,欢迎大家讨论 ,意见寄《中华烧伤杂志》编辑部。　　随着科学的发展 ,烧伤创面外用药从剂型到种类愈来愈多 ,如何评价疗效和毒副作用 ?由于临床研究的方案不同 ,差异也很大 ,给临床研究和评审造成一定难度。我们试图找到一个规范的、科学的、可操作性的方案 ,现初步拟定一个草案 ,请大家讨论、补充 ,以便更加完善。一、进行临床试验前应完成以下工作1.毒…     

银锌霜在大面积烧伤中的应用

目的总结1991年1月至1995年11月银锌霜在48例TBSA大于30％的烧伤病人创面的应用。方法将同期应用碘络醚的35例病人作为对照,两组病人的平均年龄、烧伤面积、Ⅲ度面积无显著差别,用药方式均以半暴露为主。结果银锌霜组能显著增加细菌转阴率,减少抗生素应用时间及植皮手术次数,缩短愈合时间。结论银锌霜具有较强的抗感染能力,是大面积烧伤病人的良好外用药。     

银锌霜在大面积烧伤中的应用

目的总结１９９１年１月至１９９５年１１月银锌霜在４８例ＴＢＳＡ大于３０％的烧伤病人创面的应用。方法将同期应用碘络醚的３５例病人作为对照，两组病人的平均年龄、烧伤面积、Ⅲ度面积无显著差别，用药方式均以半暴露为主。结果银锌霜组能显著增加细菌转阴率，减少抗生素应用时间及植皮手术次数，缩短愈合时间。结论银锌霜具有较强的抗感染能力，是大面积烧伤病人的良好外用药。     

Ⅱ度烧伤创面外用药的药物经济学评价

药物经济性近年来逐渐受到重视。药物上市前的药物经济学（pharmacoeconomics，PE）评价较多，而上市后的评价较少。对于烧伤创面外用药，往往仅对用药后创面愈合的时间和质量进行评价，鲜见考虑其PE。为此，笔对2001年10月-2005年12月本单位烧伤患创面应用较多的纳米银敷料。及常规使用的磺胺嘧啶银霜进行了PE评价和比较。     

Activity of topical antimicrobial agents against multidrug-resistant bacteria recovered from burn patients

Background

Topical antimicrobials are employed for prophylaxis and treatment of burn wound infections despite no established susceptibility breakpoints, which are becoming vital in an era of multidrug-resistant (MDR) bacteria. We compared two methods of determining topical antimicrobial susceptibilities.

Methods

Isolates of Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae, and Acinetobacter baumanii-calcoaceticus (ABC) from burn patients were tested using broth microdilution and agar well diffusion to determine minimum inhibitory concentrations (MICs) and zones of inhibition (ZI). Isolates had systemic antibiotic resistance and clonality determined. MDR included resistance to antibiotics in three or more classes.

Results

We assessed 22 ESBL-producing K. pneumoniae, 20 ABC (75% MDR), 20 P. aeruginosa (45% MDR), and 20 MRSA isolates. The most active agents were mupirocin for MRSA and mafenide acetate for the gram-negatives with moderate MICs/ZI found with silver sulfadiazene, silver nitrate, and honey. MDR and non-MDR isolates had similar topical resistance. There was no clonality associated with resistance patterns.

Conclusion

Despite several methods to test bacteria for topical susceptibility, no defined breakpoints exist and standards need to be established. We recommend continuing to use silver products for prophylaxis against gram-negatives and mafenide acetate for treatment, and mupirocin for MRSA.     

The use of topical, un-buffered sodium hypochlorite in the management of burn wound infection

Background

Burn wound infections are a major cause of morbidity and mortality. The bactericidal action of sodium hypochlorite has been known for centuries and it has been in clinical practice for over 70 years. Whereas a buffered sodium hypochlorite solution is not universally available, an un-buffered solution is cheap and easy to prepare.

Aim

The aim of this study was to determine the optimum concentration with regard to safety and efficacy, as well as shelf life of an un-buffered sodium hypochlorite solution for the topical management of burn wound infections.

Methods

Human fibroblasts were exposed to serial dilutions of un-buffered sodium hypochlorite solutions for 30 min and assessed for viability. Isolates of Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes were exposed to the same dilutions of un-buffered sodium hypochlorite to establish the minimum bactericidal concentration. The pH, osmolality and electrolyte concentrations were measured. These experiments were repeated with solution stored at room temperature for 6 consecutive days.

Results

24% of fibroblasts were viable after exposure to a 0.025% solution and 98.9% with a 0.003% solution. The MBC for the P. aeruginosa isolates was 0.003%, for S. aureus was 0.006% and for S. pyogenes was 0.0015%. This remained constant for 6 consecutive days. The un-buffered 0.0025% solution has a pH of 10, an osmolality of 168 sodium concentration of 89 mmol/dl and chloride of 84 mmol/dl. This remained stable for 14 days.

Conclusions

An un-buffered solution of sodium hypochlorite with a concentration of 0.006% would be suitable for the topical management of burn wound infections caused by common pathogens. It has a shelf life of at least 6 days.     

A comparative study of the effect of different topical agents on burn wound infections

Background:

Topical agents are used to treat burn wound infections.

Aims and Objective:

The present work was aimed to find out the in vitro efficacy of different topical agents against burn wound pathogens.

Settings and Design:

Randomly selected gram-positive (29) and gram-negative bacterial (119) isolates from burn wound cases admitted in burn unit of Choithram Hospital and Research Centre, Indore, were included in the in vitro activity testing for silver nitrate, silver sulphadiazine (SSD), chlorhexidine, cetrimide, nitrofuran, soframycin, betadine, benzalkonium chloride and honey by growth inhibition on agar medium.

Materials and Methods:

Multidrug-resistant isolates of gram-positive and gram-negative bacteria were checked for different topical agents. 1% topical agent was mixed with Mueller-Hinton agar. Two microlitres of bacterial suspension adjusted to 0.5 McFarland turbidity standard was spread over the topical agent containing plates. The plates without the topical agent were used as control plates. The plates were incubated for 48 h at 37°C.

Results:

SSD (148/148), silver nitrate (148/148) and chlorhexidine (148/148) showed excellent activity against all the pathogens. Neosporin had poor activity against Pseudomonas aeruginosa, (4/44) Proteus spp. (2/4) and group D streptococci (1/4). Betadine did not show activity against the bacterial isolates in the presence of organic matter. Honey did not exert any antimicrobial activity under the study conditions.

Conclusion:

SSD, silver nitrate and chlorhexidine have excellent activity against all the bacterial pathogens and could be used empirically, while identification of the infective agent is required for selecting the alternative topical agents such as nitrofuran, soframycin, and benzalkonium chloride.KEY WORDS: Benzalkonium chloride, burn wounds, cetrimide, chlorhexidine, nitrofuran, silver nitrate, silver sulphadiazine, topical gents     

湿润烧伤膏抗感染作用的实验研究

我们采用大鼠２０％Ⅲ度烫伤创面接种绿脓杆菌ＡＴＣＣ－２７８５３作为实验治疗模型，旨在评价湿润烧伤膏外用治疗烧伤的防治感染功效。于接种绿脓杆菌后１０分钟、８小时、２４小时和４８小时开始外用湿润烧伤膏治疗，并以１％的Ａｇ－ＳＤ霜，１．２％的Ａｇ－ＦＬＸ霜和基础霜剂作为对照。治疗４８小时后送血培养，痂下细菌计数及组织病理学检查，以此作为评价指标。４种外用药物在体外对绿脓杆菌，大肠杆菌和金黄色葡萄球菌做抑菌试验，结果表明，Ａｇ－ＦＬＸ抗菌作用和疗效最强，Ａｇ－ＳＤ次之，而湿润烧伤膏的各项指标和基础霜剂间差异无显著意义（Ｐ＞０．０５）。说明湿润烧伤膏在防治烧伤感染方面几乎没有作用。     

不同时期烧伤创面细菌生态学调查

目的分析笔者单位近年来烧伤创面细菌的流行趋势,探讨影响烧伤创面细菌生态学变化的因素。方法对1999年1月～2000年12月210例住院患者进行创面细菌生态学调查,与70年代初期,80年代中期和90年代初期所作调查进行比较。结果1999年以来G+球菌(52.17％)较前三个时期均显著增加(P＜0.01),而G-杆菌(46.48％)较前三个时期均显著减少(P＜0.01)。铜绿假单胞菌较1970年1月～1971年12月和1993年2月～1994年12月显著下降(P＜0.01),金黄色葡萄球菌较1985年1月～1986年12月和1993年1月～1994年12月显著上升(P＜0.01),而耐甲氧西林金黄色葡萄球菌(MRSA)占85％左右,较80年代中期和90年代初期显著增加(P＜0.01),呈不断上升的趋势。结论笔者单位近年金黄色葡萄球菌的上升趋势可能与自90年代中期开始将亚胺培南作为首选抗生素有关;万古霉素并不能减少MRSA在金葡菌中的比例。