Midnight removal of urinary catheters — Improved outcome after gynecological surgery

By convention, most indwelling urethral catheters are removed in the morning. The authors carried out a randomized prospective study of 101 patients with postoperative urethral catheters and compared midnight removal with the more usual practice of morning removal. Patients were randomized into two groups: group A (n=46) had their catheters removed at 6:00 am and group B (n=49) had their catheters removed at midnight. Six patients were excluded from the study (1 patient on distigmine and 5 with preexisting urinary tract infections). The groups were comparable in age, use of night sedation, operative procedures and incidence of postoperative urinary tract infections. Patients in group B passed urine a median of 1 hour 40 minutes earlier, with a median volume 175 ml greater than group A (P=0.012 and <0.001); 13 patients in group A subsequently required recatheterization for urinary retention, compared to only 6 patients in group B. Patients in group B were also discharged significantly earlier from hospital (median of 2 days earlier from removal of catheter) than those in group A (P=0.032). Midnight removal of indwelling catheters after gynecologic surgery significantly decreases hospitalization and improves bladder function in terms of time and volume of first void.     

Comparison of two different cell culture methods in evaluation of biocompatibility of latex urinary catheters

Summary International biocompatibility standards for urinary catheters have not yet been set. The used in vivo animal tests earlier have been shown to be insensitive and expensive. The present study compared the sensitivity and other properties of two in vitro cell culture methods, the reference method of the British Standards Institution (BSI) [2] and the thymidine incorporation method DNA synthesis inhibition test, [7]. The cell culture toxicities of thirty-seven latex catheters were measured and 84.8% of the catheters tested passed the BSI reference test while 94.6% passed the thymidine incorporation test. The overall batch-to-batch correlation was poor (p > 0.05), but within brands the correlation was better. This is obviously to be explained by the differences the characteristics of the tests and/or the chemical composition of the catheters. The thymidine incorporation test is easier to perform, requires less manpower, and is therefore less liable to subjective interpretations than the BSI test. The biocompatibility toxicity limits for latex urinary catheters need to be tightened. Our experience in this study indicates that the thymidine incorporation test or tests similar to it, which can be highly automated can be recommended for biocompatbility screening in large series, and BSI reference test can be used additionally in unclear cases.     

Infection of catheterised patients: bacterial colonisation of encrusted Foley catheters shown by scanning electron microscopy

Summary The surfaces of 32 encrusted urinary catheters were examined by scanning electron microscopy to investigate the association of bacteria with the encrusting deposits. Deposits consisted of struvite crystals surrounded by aggregates of very small crystallites of hydroxyapatite. Underneath these minerals there was a layer of closely packed bacteria. Impressions of bacteria were also observed in hydroxyapatite. Crystals were often engulfed by the bacterial layer, which thus appeared to bind the crystals to each other and to the catheter surface. This thick layer of bacteria associated with crystals may protect both the bacteria from antibiotics and the crystals from acidic bladder washout solutions intended to dissolve them. Furthermore, the existence of this sessile population explains why urease-producing bacteria are not invariably detected in the urine of patients with encrusted catheters. The observation of this bacterial layer (or biofilm) by scanning electron microscopy provided direct evidence for infection being implicated in catheter encrustation.     

Bacterial adherence to Foley urinary catheters

Bacterial adherence to the surfaces of indwelling urethral (Foley) catheters is briefly reviewed. In addition, crystal adhesion to the catheters is described. Using scanning electron microscopy, micro-organisms including fungi and crystals are frequently observed in association with fibrillar material. Based on our study using the immunofluorescence method, some of the fibrillar material is considered to be fibrin. On the surfaces of catheters, especially those indwelling for long periods, microorganisms are often embedded in biofilms, which are composed of an amorphous matrix. Urease-producing bacteria adherent to the catheters are considered to play an important role in the formation of the calculous encrustation.     

尿路感染中段尿病原菌的分布及耐药性

Objective To analyze the distribution and antimicrobial resistance of pathogenic bacteria in urinary tract infection (UTI) so as to provide evidence for appropriate selection of antimicrobial agents in clinical practice. Methods From January 2001 to December 2008 in Shanghai Ruijin Hospital, 4683 strains of pathogenic bacteria isolated from urine samples were detected by ATB system; drug susceptibility test was performed with disk diffusion method and pathogenic bacteria distribution and drug resistance was analyzed with WHO NET 5.3 software. Results Among 4683 strains of pathogenic bacteria, most was gram-negative bacilli, accounting for about 77.8%, of which predominant strain was Escherichia coli (68.7%, 3217/4683). The predominant strain of gram-positive bacteria was Enterococcus faecalis, accounting for 10.0% (468/4683). Escherichia coli showed high resistance rates to ampicillin, piperacillin and compound sulfamethoxazole (SMZ-TMP), which were 76.6%, 61.7% and 57.4% respectively, while a low resistance to imipenem, cefoperazone-sulbactam, piperacillin-tazobactam. Enterococcus faecalis showed high resistance rates to erythromycin, gentamicin and levofloxacin, which were 65.8%, 43.2% and 31.1% respectively, and were most susceptive to vancomycin and teicoplanin, both with resistance rates of 0. The susceptibility rate of Enterobacteriaceae to imipenem was 100%. From 2006 to 2008, the detection rate of extend-spectrum ?茁-lactamases ESBLs -producing Escherichia coli in outpatient increased year by year, from 28.7% to 43.3% (P<0.05), whereas no significant change was found in inpatients. The detection rate of (ESBLs)-producing Escherichia coli in inpatients was significantly higher than that in outpatients (P<0.05). The detection rate of ESBLs-producing Escherichia coli was 23.6%. The antimicrobial resistance rate in elderly patients was significantly higher than that in overall antimicrobial resistance rate (P<0.05). Conclusions The predominant bacteria of UTI are still gram-negative bacteria, main of which is Escherichia coli. Bacteria are resistant to a variety of antibiotics. Approximate selection of antibiotics in clinical practice should be made on the basis of susceptibility test results.     

Increased risk of urinary tract infection associated with the use of calcium supplements

Summary Since ions are known to influence the interaction between cells, we undertook an examination of the effect of various ions on bacterial adherence to uroepithelial cells. While most of the ions examined had no effect or decreased bacterial adherence, calcium ions significantly increased bacterial adherence. It was demonstrated, in vitro that as the concentration of calcium was increased to levels higher than normally found in the urine, there was a significant increase in bacterial adherence. It was also found that if the diet was supplemented with calcium there was an increase in the excretion of calcium in the urine and a corresponding increase in bacterial adherence when bacteria and uroepithelial cells were incubated in this urine. It is suggested that an excretion of excess calcium in the urine may lead to increased bacterial adherence in vivo and an increased potential for urinary tract infections.     

Assessment of silver-coated urinary catheter toxicity by cell culture

Summary The toxicity of silver-coated urinary catheters was assessed using a cell culture technique. The inhibitory effect of catheter extracts on the uptake of ³H-labelled thymidine by mouse fibroblasts was measured. The results show that silver-coating had no toxic effect whereas silvernitrate and silversulphate coating did have a toxic effect.     

脑卒中患者尿路感染病原菌分布及耐药性分析

目的调查本院脑卒中患者合并尿路感染的病原菌分布及耐药状况,以指导临床合理应用抗菌药物。方法选择本院2009年1月至2012年6月共145例脑卒中合并尿路感染住院患者,按照《全国临床检验操作规程》进行尿细菌培养,药敏试验采用K-B方法。结果脑卒中患者尿路感染分离病原菌均有不同程度的耐药,主要病原菌为大肠埃希菌、粪肠球菌、肺炎克雷伯菌、铜绿假单胞菌、金黄色葡萄球菌和真菌等,分别占48.97%（71/145）、13.10%（19/145）、6.89%（10/145）、6.21%（9/145）、4.83%（7/145）和8.97%（13/145）,其中部分大肠埃希菌呈多药耐药。结论脑卒中患者多为老年人,该类患者基础疾病多,自理能力差,多合并神经源性膀胱,尿路感染发病率高,病原菌耐药性不断增加,须采取有效的干预措施预防和控制感染的发生。     

初次髋膝关节置换术中不留置尿管的可行性和安全性研究

目的探讨单侧初次髋或膝关节置换术中不常规留置尿管的可行性及安全性,以减少不必要的导尿,提高患者就医舒适度和满意度。 方法本文回顾性分析中日友好医院骨关节外科2015年11月至2016年10月期间109例无明显尿潴留高危因素、无术前尿路感染、无尿路刺激征及重度肝肾功能不全、且接受单侧初次髋或膝关节置换术、术中不留置尿管(NIC)患者的资料。根据配对条件,与同期行常规术前留置尿管(IC)的单侧初次髋或膝关节置换患者按照1 ∶1进行配对研究,应用SPSS 19.0统计学软件对正态分布计量资料采用配对t检验,非正态分布计量资料采用Wilcoxon符号秩和检验,计数资料采用χ²检验分析比较两组患者术后的尿潴留、二次尿潴留、尿管相关膀胱不适、尿路刺激症、尿路感染、不良事件发生率,以及术后住院时间及患者满意度,分析并评价不留置尿管在单侧初次髋、膝关节置换术中的可行性及安全性。 结果两组患者术后尿潴留、二次尿潴留、尿路感染发生率比较,差异无统计学意义(P>0.05),NIC组术后尿管相关膀胱不适、尿路刺激征、不良事件发生率及术后住院时间均明显低于IC组,而患者满意度高于IC组,两组比较差异有统计学意义(χ²＝10.844,P<0.05),单侧初次髋或膝关节置换术中不必要的导尿高达81.7%。 结论初次髋或膝关节置换术中不常规留置尿管安全可靠,能有效减少尿管相关膀胱不适、尿路刺激征及不良事件的发生,同时可缩短术后住院时间,提高患者早期满意度。     

改良留置导尿管相关尿路感染病原菌及感染危险因素研究

目的 研究改良留置导尿管相关尿路感染患者病原菌的分布情况,分析改良留置导尿管患者尿路感染的危险因素。方法 纳入2018年3月至2020年3月邯郸市第一医院收治的168例改良留置导尿管患者作为研究对象,观察所有患者尿路感染和病原菌分布情况。将发生尿路感染和未发生尿路感染的患者收集资料并进行对比,差异有统计学意义项目代入Logistic回归方程计算,分析改良留置导尿管患者发生尿路感染的危险因素。结果 168例改良留置导尿管患者中有49例患者发生尿路感染,发生率为29.17%。共检出病原菌84株。其中革兰阴性杆菌50株（59.52%）,革兰阳性球菌24株（28.57%）,真菌10株（11.90%）。发生尿路感染和未发生尿路感染患者在年龄、住院时间、留置导尿管时间、糖尿病、肾结石、低蛋白血症以及抗菌药物使用种类上对比差异均有统计学意义（P<0.05）。将上述项目代入Logistic回归方程计算发现,年龄≥60岁、住院时间≥21 d、留置导尿管时间≥13 d、合并糖尿病、合并肾结石、合并低蛋白血症以及尿路感染前抗菌药物使用种类≥3种均是改良留置导尿管患者发生尿路感染的危险因素。结论 改良留...     

The effect of repeated instillations of antiseptics on catheter-associated urinary tract infections: a study in a physical model of the catheterized bladder

Summary The activity of three antiseptic bladder washout solutions was examined in a physical model of the catheterized bladder. Tests were performed against cultures of four common urinary tract pathogens that had established themselves in the model and colonized the surfaces with biofilm. Double instillations of chlorhexidine (0.02% w/v) at 6-h intervals failed to eliminate Pseudomonas aeruginosa, Proteus mirabilis, and Providencia stuartii from the bladder model. Escherichia coli, however, was susceptible to a second instillation provided that it was performed within 12 h. Supplementing chlorhexidine with EDTA and TRIS potentiated its activity against E. coli. Mandelic acid (1.0% w/v) was the most effective of the agents, double instillations eliminating all but Pr. mirabilis infections.     

Efficacy and safety of urinary catheters with silver alloy coating in patients with spinal cord injury: a multicentric pragmatic randomized controlled trial. The ESCALE trial

Background

Patients with spinal cord injury (SCI) who carry indwelling urinary catheters have an increased risk of urinary tract infection (UTI). Antiseptic silver alloy-coated (SAC) silicone urinary catheters prove to be a promising intervention to reduce UTIs; however, current evidence cannot be extrapolated to patients with SCI.

The severance of epidural catheters

Four groups of Portex Minipack epidural sets were tested to measure the force required to sever the catheter on the needle bevel. The 18-gauge radio-opaque catheter was found to sever at a significantly lower applied force and to stretch significantly less before breaking than the 18-gauge clear catheter or either of the 16-gauge catheters. The other catheters tested had breaking strains of between 10-20 Newtons (1-2 kg force) and stretched by more than 30% of their lengths before breaking. It is suggested that these other catheters may therefore be a preferable alternative to the 18-gauge radio-opaque.     

Force exerted by epidural catheters

In a study of epidural catheters, it was found that catheter material and catheter diameter both influenced in force exerted. Catheters made of nylon exert less force than those made of polyethylene. Diameter is proportional to the logarithm of force exerted.     

A study of the structure of the crystalline bacterial biofilms that can encrust and block silver Foley catheters

The aim of this study was to examine the structure of the crystalline bacterial biofilms that encrust and block silver/hydrogel-coated latex catheters. Scanning electron microscopy was used to examine the crystalline deposits that were found encrusting catheters obtained from six patients undergoing long-term catheterization in a community setting. Large populations of bacilli and cocci were seen on all catheters developing on a basal foundation layer of crystalline material. These observations show that in patients prone to catheter encrustation, crystalline material formed in the urine can cover the surfaces of silver catheters. Extensive bacterial biofilms then develop on the crystals, shielded from the underlying silver. It is suggested that if antimicrobials are to be incorporated into catheters to prevent encrustation, they must diffuse out from the catheter surface and reduce the viable cell populations of the urease producing bacteria that elevate the urinary pH and trigger crystal formation.     

Differential flow from multihole epidural catheters

The pressures used in vivo to administer epidural doses of local anaesthetic were recorded for 16- and 18-gauge multihole catheters. Observations were made on 10 patients in labour for each catheter gauge. The pressure range for the 16-gauge catheters was 39.9-266 kPa, with a mean of 167.2 kPa, and for 18-gauge, a range of 53.2-266 kPa, mean, 159 kPa. Similar pressures were then applied in vitro to 10 catheters of each gauge, and the flow of fluid observed from the three holes. For each size of catheter, with increasing pressure, flow appeared at the proximal, then the middle, and finally the distal hole. This emphasises that the effect of epidural doses can vary depending on the pressure of injection, especially if the catheter had been passed partially through the dura.     

The effect of EDTA instillations on the rate of development of encrustation and biofilms in Foley catheters

The aim of this research was to examine whether a daily instillation of tetra sodium ethylenediaminetetraacetic acid (EDTA) solution could reduce the rate at which encrustation by crystalline Proteus mirabilis biofilms blocks urinary catheters. Sets of three bladder models were fitted with size 14 all-silicone catheters. Tetra sodium EDTA solution was instilled into the catheter following biofilm development. Catheters were examined by digital photography and scanning electron microscopy for evidence of encrustation. The results showed that the mean time to blockage of the control catheters was 45 h for saline, 57 h for water and 67 h for those exposed to daily instillations of the EDTA solution. Statistical analysis confirmed that the mean encrustation rate on the EDTA-treated catheters was significantly lower than on the control-treated devices (P = 0.047). This in vitro study indicates that EDTA may have beneficial effects in reducing the complication of catheter encrustation and blockage by crystalline biofilms.