DNA fingerprinting analysis of coagulase negative staphylococci implicated in catheter related bloodstream infections

AIMS: The epidemiological assessment of cases of coagulase negative staphylococcal catheter related bloodstream infection. METHODS: Two hundred and thirty patients with suspected catheter related bloodstream infection were evaluated over a two year period. Central venous catheters were cultured both endoluminally and extraluminally. Peripheral blood, catheter hubs, skin entry, and skin control sites were also cultured. Pulsed field gel electrophoresis (PFGE) was used to DNA fingerprint coagulase negative staphylococci isolated from patients with presumptive catheter related bloodstream infection. RESULTS: Sixty cases of catheter related bloodstream infection were identified, 21 of which were attributed to coagulase negative staphylococci. Two hundred and ninety four separate isolates of coagulase negative staphylococci from the 21 cases of catheter related bloodstream infection were subjected to PFGE (mean of 14 for each case). Catheter related bloodstream infection was only confirmed by PFGE analysis in 16 of the 21 cases because in the remaining five cases peripheral blood and central venous catheter coagulase negative staphylococci isolates were different. Skin entry, control skin, and central venous catheter hub isolates matched peripheral blood isolates in six, four, and seven cases, respectively. Coagulase negative staphylococci isolates could not be cultured from the patients’ own skin in seven cases of catheter related bloodstream infection. Central venous catheter lumens were colonised in all cases of catheter related bloodstream infection compared with 44–81% of cases that had positive external surface catheter tip cultures, depending on the threshold used to define significant growth. CONCLUSIONS: Catheter related bloodstream infection as a result of coagulase negative staphylococci may be over stated in about a quarter of cases, unless a discriminatory technique is used to fingerprint isolates. No single, simplistic route of bacterial contamination of central venous catheters was identified, but endoluminal catheter colonisation is invariably present in cases of catheter related bloodstream infection. The use of central venous catheters as a means of access for monitoring and as a route of administration of drugs has become almost mandatory in patients with serious illnesses. Infections of central venous catheters are common and coagulase negative staphylococci remain the most frequent pathogens—for example, 37% of 1267 isolates in one meta-analysis.Controversy remains over the source of, and route of access by, these bacteria to the central venous catheters. Recent developments, such as catheters with antimicrobial properties, are an important advance, but until such issues are resolved it remains unclear how best to reduce the risk of catheter related bloodstream infection. “Pulsed field gel electrophoresis is well recognised as the gold standard for fingerprinting coagulase negative staphylococci” Because there are at least 33 distinct coagulase negative staphylococci species that have been identified, and because methods that use phenotyping alone cannot accurately distinguish between strains of coagulase negative staphylococci, DNA fingerprinting is required to clarify the epidemiology of coagulase negative staphylococci catheter related bacterial bloodstream infection. Despite the accepted difficulties in determining the relatedness of coagulase negative staphylococci, diagnostic laboratories routinely rely on limited information from phenotypic tests to compare isolates fro

Suture-method versus Through-the-needle Catheters for Continuous Popliteal-sciatic Nerve Blocks: A Randomized Clinical Trial.

BACKGROUND:The basic perineural catheter design has changed minimally since inception, with the catheter introduced through or over a straight needle. The U.S. Food and Drug Administration recently cleared a novel perineural catheter design comprising a catheter attached to the back of a suture-shaped needle that is inserted, advanced along the arc of its curvature pulling the catheter past the target nerve, and then exited through the skin in a second location. The authors hypothesized that analgesia would be noninferior using the new versus traditional catheter design in the first two days after painful foot/ankle surgery with a primary outcome of average pain measured with the Numeric Rating Scale. METHODS:Subjects undergoing painful foot or ankle surgery with a continuous supraparaneural popliteal-sciatic nerve block 5 cm proximal to the bifurcation were randomized to either a suture-type or through-the-needle catheter and subsequent 3-day 0.2% ropivacaine infusion (basal 6 ml/h, bolus 4 ml, lockout 30 min). Subjects received daily follow-up for the first four days after surgery, including assessment for evidence of malfunction or dislodgement of the catheters. RESULTS:During the first two postoperative days the mean ± SD average pain scores were lower in subjects with the suture-catheter (n = 35) compared with the through-the-needle (n = 35) group (2.7 ± 2.4 vs. 3.4 ± 2.4) and found to be statistically noninferior (95% CI, -1.9 to 0.6; P < 0.001). No suture-style catheter was completely dislodged (0%), whereas the tips of three (9%) traditional catheters were found outside of the skin before purposeful removal on postoperative day 3 (P = 0.239). CONCLUSIONS:Suture-type perineural catheters provided noninferior analgesia compared with traditional catheters for continuous popliteal-sciatic blocks after painful foot and ankle surgery. The new catheter design appears to be a viable alternative to traditional designs used for the past seven decades

<i>Candida albicans</i> fungaemia following traumatic urethral catheterisation in a paraplegic patient with diabetes mellitus and candiduria treated by caspofungin

A 58-year-old paraplegic male, with long-term indwelling urethral catheter, developed catheter block. The catheter was changed, but blood-stained urine was drained intermittently. A long segment of the catheter was seen lying outside his penis, which indicated that the balloon of Foley catheter had been inflated in urethra. The misplaced catheter was removed and a new catheter was inserted correctly. Gentamicin 160 mg was given intravenously; meropenem 1 gram every eight hours was prescribed; antifungals were not given. Twenty hours later, this patient developed distension of abdomen, tachycardia, and hypotension; he was not arousable. Computed tomography of abdomen revealed inflamed uroepithelium of right renal pelvis and ureter, 4 mm lower ureteric calculus with gas in right ureter proximally, and vesical calculus containing gas in its matrix. Urine and blood culture yielded &lt;i&gt;Candida albicans&lt;/i&gt;. Identical sensitivity pattern of both isolates suggested that the source of the bloodstream infection was most likely urine. Both isolates formed consistently high levels of biofilm formation in vitro as assessed using a biofilm biomass stain, and high levels of resistance to voriconazole were observed. Both amphotericin B and caspofungin showed good activity against the biofilms. HbA1c was 111 mmol/mol. This patient was prescribed human soluble insulin and caspofungin 70 mg followed by 50 mg daily intravenously. He recovered fully from candidemia

Comparison of symmetrical hemodialysis catheters using computational fluid dynamics

Purpose: Symmetric-tip dialysis catheters have become alternative devices because of low access recirculation and ease of tip positioning. Flow characteristics of three symmetric catheters were compared based on computational fluid dynamics (CFD) as they relate to catheter function. Materials And Methods: In Palindrome, GlidePath, and VectorFloW catheters, a computational fluid dynamics based approach was used to assess W regions of flow separation, which are prone to thrombus development; (ii) shear-induced platelet activation potency; (iii) recirculation; and (iv) venous outflow deflection. A steady-state, laminar flow model simulated: catheter tip position within the superior vena cava. Catheter performance was investigated at high hemodialysis flow rate (400 mL/min). Blood was assumed as a Newtonian fluid. Results: Wide regions of flow separation downstream of the Palindrome side slot and close to the distal tip were observed in forward and reversed line configurations. Geometric asymmetry of the distal guide wire aperture of the GlidePath catheter produced the highest levels of inverted velocity flow when run in reversed configuration. The lowest mean shear-induced platelet activation was exhibited by GlidePath and VectorFloW catheters; the Palindrome catheter exhibited 152% higher overall platelet activation potency. All catheters were associated with a recirculation close to zero; the helically contoured lumens of the VectorFlow catheter produced the greatest amount of deflection of venous flow away from the arterial lumen. Conclusions: The VectorFlow catheter produced less shear-induced platelet activation than the Palindrome catheter and less flow separation than the Palindrome and GlidePath catheters irrespective of line configuration These findings have,potential implications for differences in thrombogenic risk during clinical performance of these catheters

Advanced ablation strategies for management of post-surgical atrial arrhythmias.

Post-surgical arrhythmias include a wide range of arrhythmias occurring late after cardiac surgery and represent a complex substrate for catheter ablation either because of extended scar and remodeling or because of limited access to the area of interest. Novel image integration and ablation tools have made the catheter ablation in this population both feasible and successful. We review a structured approach to catheter ablation of post-surgical atrial arrhythmias in various patient cohorts including the most common congenital heart defects

A central line care maintenance bundle for the prevention of central line–associated bloodstream infection in non–intensive care unit settings

OBJECTIVE: To evaluate a central line care maintenance bundle to reduce central line-associated bloodstream infection (CLABSI) in non-ICU settings. DESIGN: Before-after trial with 12 month follow-up period. SETTING: 1250-bed teaching hospital. PARTICIPANTS: Patients with central lines on eight general medicine wards. Four wards received the intervention and four served as controls. INTERVENTION: A multifaceted catheter care maintenance bundle consisting of educational programs for nurses, update of hospital policies, visual aids, a competency assessment, process monitoring, regular progress reports, and consolidation of supplies necessary for catheter maintenance. RESULTS: Data were collected for 25,542 catheter-days including 43 CLABSI (rate = 1.68 per 1,000 CL-days) and 4,012 catheter dressing observations. Following the intervention, a 2.5% monthly decrease in the CLABSI incidence density was observed on intervention floors, but this was not statistically significant (95% confidence interval (CI); −5.3 – 0.4). On control floors, there was a smaller, but marginally significant decrease in CLABSI incidence during the study (change in monthly rate = −1.1%; 95% CI, −2.1 - −0.1). Implementation of the bundle was associated with improvement in catheter dressing compliance on intervention wards (78.8% compliance pre-intervention vs. 87.9% during intervention/follow-up; p<0.001) but improvement was also observed on control wards (84.9% compliance pre-intervention vs. 90.9% during intervention/follow-up; P = .001). CONCLUSIONS: A multi-faceted program to improve catheter care was associated with improvement in catheter dressing care, but no change in CLABSI rates. Additional study is needed to determine strategies to prevent CLABSI in non-ICU patients

The Malta experience : a retrospective study of two types of peritoneal dialysis catheters

Aim: The aim of this retrospective study was to compare the one year and two year survival rate of the double cuff coiled Tenchkoff catheter (TC) and the double cuff coiled Swan Neck (SN) catheter. The incidence of the following complications in the two groups were assessed: exit site infection (ESI), tunnel infection (TI), peritonitis (P), flow problems (FP), catheter tip migration (CTP), hernia development (H) and leakage (L). Methods: This is a retrospective comparative study of peritoneal dialysis catheters inserted between January 2003 and December 2008 by one surgical team at Mater Dei Hospital. Results: The one year catheter survival rate was TC 88.5% and SN 90%. There was no statistically significant difference in catheter survival rate between the two cohorts. The survival rate at 2 years post implantation of the TC catheters was 82.6% and 88.8% for the SN catheters. Conclusions: Equally good results were obtained with the two types of peritoneal dialysis catheters studied. There was no significant difference in 1 and 2 year survival between the two types of catheters. In our local experience the catheter survival rate and episodes of peritonitis per year at risk are in line with the recommendations of the International Society of Peritoneal Dialysis (ISPD).peer-reviewe

Heart catheter cable and connector

Ultraminiature catheter cables that are stiff enough for intravenous insertion yet flexible at the tip, sterilizable, and economical are fabricated entirely from commercially available parts. Assembly includes air passageway for reference pressures and coaxial cable for transmission of signals from the tip of catheter

The Impact of a Nurse-Driven Foley Catheter Removal Protocol on Catheter Associated Urinary Tract Rates in Critical Care Areas

Background: Indwelling urinary catheters serve a purpose in critical care; however, they can also pose a risk for patients. With increased catheter use, there is an increased risk of developing a catheter associated urinary tract infection (CAUTI). CAUTIs lead to longer length of stay for patients, antibiotic treatment, and have a financial burden to the institution. The objective of this study was to determine if a nurse driven catheter removal protocol could reduce CAUTIs in critical care units. Methods: Retrospective review of CAUTI data from the National Healthcare Safety Network (NHSN) was observed three months prior to the protocol implementation and three months post implementation. Results: There were seven CAUTIs reported prior to the protocol implementation and five post implementation. There was also an increase noted in catheter days post implantation. There was a 29% reduction in CAUTI rate (p = 0.5736). Discussion: While the rate reduction from pre to post protocol implementation was not statistically significant, we propose that given the reduction in CAUTIs, it is clinically significant. Conclusion: Implementation of catheter removal protocols could be a useful tool in CAUTI reduction. Further research would be beneficial in determining the association between the tool and CAUTI rate reduction

Ion beam sputter-etched ventricular catheter for hydrocephalus shunt

A cerebrospinal fluid shunt in the form of a ventricular catheter for controlling the condition of hydrocephalus by relieving the excessive cerebrospinal fluid pressure is described. A method for fabrication of the catheter and shunting the cerebral fluid from the cerebral ventricles to other areas of the body is also considered. Shunt flow failure occurs if the ventricle collapse due to improper valve function causing overdrainage. The ventricular catheter comprises a multiplicity of inlet microtubules. Each microtubule has both a large openings at its inlet end and a multiplicity of microscopic openings along its lateral surfaces