Catheter Hub Research Articles

A Randomized and Prospective Study of 3 Procedures for the Diagnosis of Catheter-Related Bloodstream Infection without Catheter Withdrawal

Suspicion of catheter-related bloodstream infection (CR-BSI) leads frequently to unnecessary catheter withdrawals, and many catheter-tip cultures yield negative results. The objective of this study was to compare the yield of 3 microbiological procedures to assess CR-BSI without catheter withdrawal. The study was prospectively performed in a group of patients without neutropenia or blood disorders who were admitted to the intensive care unit during a 37-month period with sepsis suspected on clinical grounds and who had central venous catheters inserted for >48 h. The microbiological procedures compared were semiquantitative cultures from hub and skin (superficial), differential quantitative blood cultures, and differential time to positivity between cultures of blood obtained from catheter hubs and peripheral blood. Of the 204 episodes of suspected CR-BSI included in the study, 28 were confirmed to be CR-BSI. We obtained the following results for sensitivity, specificity, positive and negative predictive values, and accuracy: superficial cultures, 78.6%, 92.0%, 61.1%, 96.4%, and 90.2%, respectively; differential quantitative blood cultures, 71.4%, 97.7%, 83.3%, 95.6%, and 94.1%, respectively; and differential time to positivity, 96.4%, 90.3%, 61.4%, 99.4%, and 91.2%, respectively. CR-BSI can be assessed without catheter withdrawal in patients without neutropenia or blood disorders who have catheters inserted for a short time and are hospitalized in the intensive care unit. Convenience, use of resources, and expertise should determine the technique of choice in different medical contexts. Because of ease of performance, low cost, and wide availability, we recommend combining semiquantitative superficial cultures and peripheral vein blood cultures to screen for CR-BSI, leaving differential quantitative blood cultures as a confirmatory and more specific technique.

Etiology and pathogenesis of bloodstream infections associated with the use of long-term central vascular catheter (CVC) in patients who undergone gastrointestinal surgery

CVC is the main factor of risk of bloodstream infections. This study purpose was determining both etiology and pathogenesis of these infections in 80 patients who undergone gastrointestinal surgery and who worn long lasting CVC, in the institution HC-UFU. Cultures were made in nostril, skin of the insertion site, tip and catheter hub, in addition to hemoculture in those suspects of sepsis. The colonization incidence rate of the catheter tip was 12.5/ 1,000 catheter days and the CVC associate infection rate was 3.1/1,000 catheter days. Frequencies of skin, hub and catheter tip colonization were 13.8%, 8.9% and 13.3%, respectively. Coagulase-negative Staphylococci were the most found microorganisms in nostril (74%), skin (45.4%) and hub (75%) and Gram-negative bacilli (50%), followed by S. aureus (25%) the most common ones in catheter tip. Approximately 51% of patients received antibiotics and most of them (53.7%) had therapeutic purpose. The frequency of patients with clinical sepsis was 27.5%. Three cases of bacteremia associated with the use of CVC were detected (3.8%), with S. aureus in two of them and K. pneumoniae in the third one. There was not seen any association of skin and hub colonization with their presence in the catheter tip and in the blood of these patients, but S. aureus was recovered from nostril of those with sepsis by this pathogenic agent. A greater concern is suggested over preventive measures and control of these primary and secondary bloodstream, as well as catheter tip colonization.

Prevention of Catheter-Related Infections Using A Closed Hub System in Patients With Pulmonary Arterial Hypertension

Most of the patients with pulmonary arterial hypertension (PAH) receiving intravenous epoprostenol have experienced catheter-related infections during long-term treatment. Catheter hub was reported to be the most important source of catheter-related infections. To prevent the catheter-related infections, we have introduced a closed hub system and compared the incidence of catheter-related infections with that in patients using a non-closed hub system. We evaluated the results obtained on 24 occasions in 20 patients with PAH between June 1999 and December 2005. On 11 occasions, a non-closed hub system was used and on 13 cases a closed hub system. We classified the catheter-related infection into a catheter-related bloodstream infection (CRBSI) group or a tunnel infection group based on the pathway of bacteria. The CRBSI rate was 0.89 per 1,000 catheter days in the non-closed hub system group vs 0.10 per 1,000 catheter days in the closed hub system group. Kaplan-Meier analysis showed that the risk of CRBSI significantly decreased in the closed hub system group. None of the patients died as a direct consequence of catheter-related infection during the study period. We successfully prevented CRBSI by using a closed hub system.

Company News

ICU Medical has released the Tego Connector, the first catheter protection device designed specifically for use in hemodialysis treatments. The Tego protects the catheter from contamination during hemodialysis sessions, preventing bloodstream infections for the patient.It is a needle-free product that creates a “closed” system when attached to the hub of the catheter. The closed system eliminates any manipulation of the catheter hub while attaching or removing blood lines, which helps prevent contamination and, consequently, bloodstream infections for patients. Traditional hemodialysis delivery systems are open, and 10% of patients with a long-term central venous catheter for chronic hemodialysis will develop a bloodstream infection when using this open system.Smith & Nephew's Endoscopy division has launched the high-definition 660HD Image Management System, which can digitally capture, edit, export, and print endoscopic surgical images and patient information.Once medical practitioners select images to be captured, the OR staff can export the images to DVD, CD, or USB, and integrate them into the hospital's information technology architecture, where they can be stored with the patient's electronic medical record. The system can be configured to interface with a broad range of hospital information systems.

A simplified method of antibiotic lock therapy for Broviac–Hickman catheters using a CLC 2000 connector device

We report a simplified method of performing antibiotic lock therapy (ALT) based on a disposable central venous catheter (CVC) hub device, CLC 2000, enabling an open-ended CVC to be flushed with normal saline solution without heparin. ALT was administered through a CLC 2000 connector for recurrent CVC-bloodstream infections (BSI) by the same organism in four patients and for CVC colonization in five patients. The antibiotic concentration obtained in the lumen of the CVC with ALT was 2,500-fold higher than the minimum inhibiting concentration of targeted bacteria for patients treated with vancomycin, 2,500-80,000-fold higher for patients treated with teicoplanin, and 10,000-fold higher for the patient treated with amikacin. All CVC-BSIs treated with ALT resulted in complete clinical and microbiological responses. No case of malfunction in withdrawing or flushing the CVC and no precipitation during the administration of the antibiotic solution was observed. No recurrence of CVC-BSI or CVC colonization by the same organism was diagnosed during subsequent follow-up, despite the fact that all patients had further periods of severe neutropenia. At the last follow-up, three CVCs had been removed for other infections (fever of unknown origin in two; fungemia in one), four CVCs had been removed at the end of therapy, and one CVC is still in situ 20 months after ALT. In conclusion, a course of ALT is feasible in cancer patients with infected but much-needed CVCs before resorting to removal. The use of the CLC 2000 connector device simplifies the procedure for preparation and administration of ALT without compromising its efficacy.

Hub colonization of central line catheters in children with cancer

18530 Background: Central venous catheter (CVC) hub sites provide bacterial access to the blood stream through migration along the external and internal surfaces of the catheter. Hub colonization rates vary from 29–38% in the adult literature. While pediatric studies were not found, one study reported the incidence of blood stream infections in neonates to be 30 times higher in catheters with hub colonization compared to catheter hubs that were not colonized. The purpose of this descriptive study was to obtain baseline cultures of CVC hubs to determine the incidence of colonization. Methods: Fifty-one catheter hub cultures were obtained from a convenience sample of 27 children with cancer. The mean age of the patients was 8.2 years (range 0.5–16.2 years); 77% were diagnosed with leukemia and 23% with solid tumors. Cultures were obtained by swabbing the threaded area of the catheter hub after removing the injection cap. A semi-quantitative culture for bacteria and fungus was obtained using standard laboratory procedures by a microbiologist. This study was conducted in a large urban hospital in the Southwest. Results: Fifty-seven percent of the hubs were culture positive. Of those positive cultures, 69%, 24%, 10% and 7% were colonized with 2, 3, 4 and 5 organisms, respectively. The most common organism cultured was coagulase negative staphylococcus. The only significant risk factor for this population was previous central venous catheter infections (p = 0.025). Sixty-nine percent of the lines were tunneled catheters. Central venous catheters were in place on an average of 75.3 days but this was not a factor in the colonization rate. Conclusions: The majority (57%) of the 51 central venous catheter hubs cultured were colonized with at least one organism. This study is the first to evaluate the rate of central venous catheter hub colonization in children with cancer. These findings support the need for more stringent guidelines for central venous catheter care. Further research evaluating the relationship between hub colonization and subsequent blood stream infection is needed. No significant financial relationships to disclose.

Use of Catheters With the AgION Antimicrobial System in Kidney Transplant Recipients to Reduce Infection Risk

Microbial blood infection represents a high risk for immuno-suppressed patients. Of all catheter-related infections in the bloodstream, 90% result from the use of central venous catheters, the main cause being microbial colonization at the catheter’s insertion point or the catheter hub. Between January 2003 and December 2004, 102 patients received a renal transplant including 57 who received a triple-lumen central venous catheter (CVC) during the procedure. Two catheters were used: a standard polyurethane catheter placed in the jugular veina or the subclavian veina for group I, and polyurethane catheters with the AgION antimicrobial system always placed in the subclavian veina for group II. Care and maintenance of the CVCs was standardized in both groups. After catheter removal, the tips were analyzed microbiologically. Of 57 (43.9%) CVCs, 25 were found to be contaminated. In the first group 24 out of 41 CVCs (58.5%) showed bacterial growth, whereas in group II only one catheter (6.6%) had a biofilm. The most common contaminant (18 out of 25, 72%) was Staphylococcus epidermidis. In group II, two patients had positive blood cultures yet a microbiologically sterile CVC. None of the catheters with the AgION antimicrobial system had to be removed owing to local infection or intolerance. The continuous release of silver ions increases the protection against bacteria and fungi during the entire time of catheterization. Use of catheters with the AgION antimicrobial system lead to a marked reduction in catheter-associated infections of the bloodstream.

The challenge of anticipating catheter tip colonization in major heart surgery patients in the intensive care unit: Are surface cultures useful?

Patients undergoing heart surgery show a high risk of catheter colonization and catheter-related bloodstream infections. We evaluated whether skin insertion site and catheter hub surveillance cultures ("surface cultures") could predict catheter colonization and help establish the origin of bloodstream infections. : Prospective cohort study. An 11-bed heart surgery intensive care unit in a tertiary university hospital. Heart surgery patients spending >4 days in intensive care over an 11-month period. All catheters were surveyed. Cultures were obtained from the skin insertion site and all hubs on day 5 after surgery, every 72 hrs thereafter, and on catheter removal. Swabs were processed semiquantitatively by streaking the surface of a Columbia agar plate. Catheters were processed using Maki's method. The observation of > or = 15 colonies/plate was taken to indicate a positive skin or catheter colonization culture result. Over the study period, 561 catheters were inserted in 130 patients. The median time a catheter was in place was 6 days (interquartile range 3-11), and 3,712 surface cultures were obtained (median four per patient). Catheter colonization occurred in 133 catheters, and there were 15 episodes of catheter-related bloodstream infection (incidence density of colonization 29.3 and of catheter-related bloodstream infection 8.8 per 1,000 catheter-days). Validity indexes for the capacity of surface cultures to predict catheter colonization and catheter-related bloodstream infection, respectively, were as follows: accuracy, 71.4, 65.6; sensitivity, 83.5%, 100%; specificity, 67.1%, 64.7%; positive predictive value, 47.6%, 7.2%; negative predictive value, 91.9%, 100%; positive likelihood ratio, 2.5, 2.83; and negative likelihood ratio, 0.2, 0. Surface cultures correctly predicted 77.4% of all bacteremia episodes (catheter-related and non-catheter-related). Systematic surveillance cultures of catheter hub and skin insertion sites in patients admitted to a heart surgery intensive care unit could help identify patients who would benefit from decontamination and preventive measures and establish whether catheters are the portal of entry of bloodstream infection.

A Vancomycin-Heparin Lock Solution for Prevention of Nosocomial Bloodstream Infection in Critically Ill Neonates With Peripherally Inserted Central Venous Catheters: A Prospective, Randomized Trial

Critically ill neonates are at high risk for vascular catheter-related bloodstream infection (CRBSI), most often caused by coagulase-negative staphylococci. Most CRBSIs with long-term devices derive from intraluminal contaminants. The objective of this study was to ascertain the safety and the efficacy of a vancomycin-heparin lock solution for prevention of CRBSI. A prospective, randomized double-blind trial was conducted during 2000-2001 at a community hospital level III NICU. Very low birth weight and other critically ill neonates with a newly placed peripherally inserted central venous catheter were randomized to have the catheter locked 2 or 3 times daily for 20 or 60 minutes with heparinized normal saline (n = 43) or heparinized saline that contained vancomycin 25 microg/mL (n = 42). The origin of each nosocomial bloodstream infection (BSI) was studied by culturing skin, catheter hubs, and implanted catheter segments and blood cultures, demonstrating concordance by restriction-fragment DNA subtyping. Surveillance axillary and rectal cultures were performed to detect colonization by vancomycin-resistant organisms. The main outcome measures were (1) CRBSIs and (2) colonization or infection by vancomycin-resistant Gram-positive bacteria. Two (5%) of 42 infants in the vancomycin-lock group developed a CRBSI as compared with 13 (30%) of 43 in the control group (2.3 vs 17.8 per 1000 catheter days; relative risk: 0.13; 95% confidence interval: 0.01-0.57). No vancomycin-resistant enterococci or staphylococci were recovered from any cultures. Vancomycin could not be detected in the blood of infants who did not receive systemic vancomycin therapy. Twenty-six neonates (8 vancomycin-lock group, 18 control group) had at the end of a catheter-lock period asymptomatic hypoglycemia that resolved promptly when glucose-containing intravenous fluids were restarted. Prophylactic use of a vancomycin-heparin lock solution markedly reduced the incidence of CRBSI in high-risk neonates with long-term central catheters and did not promote vancomycin resistance but was associated with asymptomatic hypoglycemia. The use of an anti-infective lock solution for prevention of CRBSI with long-term intravascular devices has achieved proof of principle and warrants selective application in clinical practice.

MICROBIAL CONTAMINATION OF HAEMODIALYSIS CATHETER CONNECTIONS

Bacterial contamination and colonisation of the haemodialysis catheter is a reason for infection in dialysis patients. One reason for contamination may be frequent routine connections at the beginning, during and end of dialysis. Higher infection rates observed with double lumen catheters may be due to the absence of the sterile, disposable device that is fitted between the blood tubing and the catheter hubs with single lumen catheters. A sterile, disposable extension was implemented at the author's unit for use in dialysis with double lumen catheters. The proximal and distal ends of the extension were assessed for microbial contamination after standard dialysis. Results show microbial contamination in almost 30% of the samples retrieved from the extensions. Experiences in PD and the behaviour of skin bacteria on polymers, suggest that disposable extensions might have the potential to serve as a barrier or absorber for bacterial contamination.

Effectiveness of catheter hub sanitation prior to dialysis

Purpose: Contamination of catheter hub connectors is known to cause catheter‐related blood stream infections in patients undergoing hemodialysis via central venous catheters (CVC). The effectiveness of cleansing the hub with an antimicrobial agent was assessed by culturing the surface of the hub following sanitation. Methods: The CVC hub connectors of 24 patients were sanitized using the standard hospital protocol of aseptically swabbing the connectors with a solution of bleach or Betadine, and then bathing the hub in sterile gauze soaked with the antimicrobial solution for 5 minutes. The exterior surface of the hub was then cultured for a broad spectrum of microorganisms. Patients were monitored for exit site infection, tunnel infection, and septicemia. In the laboratory, sterile hubs were inoculated with E. coli, staph. aureus neg., and yeast. Hubs were then immersed in Betadine for 5, 10, or 30 min. and cultures were taken. Results: Positive cultures were obtained from the hubs of 17 of the 24 patients. Seven (7) of the patients with positive results developed bacteremia from the cultured organism within 7 weeks. Positive cultures were obtained from 50% of inoculated lab samples after 5 min, 10% after 15 min, and 0% after 30 min. of immersion sanitation. Conclusions: The techniques for cleansing CVC hubs should be revisited.

The Efficacy of the Arrow Staple Device for Securing Central Venous Catheters to Human Skin

We tested the hypothesis that the force necessary to dislodge a central venous catheter from human skin is related to its method of attachment. Specifically, we compared the peak axial force and torque required to remove a catheter hub attached to human skin with 2 3-0 silk sutures, 4 0.022-in. staples, or 4 0.025-in. staples. We used the tissue from the proximal end of discarded extremities after below-knee amputations to serve as a surrogate for the skin of living humans that would normally be the site for catheter stabilization. Central venous catheter hubs were secured to the area of grossly normal appearing tissue with 2 3-0 silk sutures or 4 staples. For each attachment method, 16 dislodgement trials were conducted. The mean peak force required for axial dislodgement with 3-0 silk sutures (40.9 +/- 10.7 N; n = 16) was more than that for 4 0.022-in. staples (34.0 +/- 7.2 N; n = 16;P = 0.04) but was not different from that for 4 0.025-in. staples (40.4 +/- 5.8 N; n = 16). The major finding of this study is that securing a central venous hub with 4 0.025-in. staples is as effective as 2 3-0 silk sutures in preventing axial dislodgement.

Effect of 24-hour intravenous tubing set change on the sterility of repackaged fat emulsion in neonates.

Duration of intravenous fat emulsion (IVFE) infusions, precise method of administration (manufactured bottle vs repackaged syringe), and interval for administration set change continue to be debated. To determine the contamination rate associated with replacing IVFE administration sets every 24 hours in newborn infants receiving fat emulsion repackaged into unit-of-use syringes. This was a prospective, microbiologic study of 90 administration sets used in 19 neonates. IVFE samples were obtained from administration sets at the end of a 19- to 23-hour infusion and prior to daily tubing set change from infants who received repackaged IVFE. Samples of IVFE (1-3 mL) were aseptically removed at the catheter connection site proximal to the patient, transferred into BACTEC PEDSPlus culture media, and continuously monitored for 5 days to detect gram-positive and gram-negative organisms, as well as yeast. Two samples (2.27%) grew coagulase-negative Staphylococcus. Both samples were from the same asymptomatic patient and were obtained on consecutive days. A blood sample obtained through this infant's central catheter grew the same organism and suggested catheter hub colonization as the primary site of microbe origin. Microbial contamination of IVFE infusion sets changed at 24-hour intervals, using unit-of-use syringes in neonates, was low at 2.2%.

Molecular epidemiology of catheter-related bloodstream infections caused by coagulase-negative staphylococci in haematological patients with neutropenia.

Catheter-related bloodstream infection (CRBSI) caused by coagulase-negative staphylococci (CNS) is common in haematological patients with febrile neutropenia. As the clinical signs of CRBSI are usually scarce and it is difficult to differentiate from blood culture contamination, we tried to confirm CRBSI by molecular typing of CNS isolated from paired blood cultures (one from a peripheral vein and another from the central venous catheter hub). Blood cultures were positive in 59 (36%) out of 163 patients. CNS were isolated in 24 (40%) patients; in 14 from paired blood cultures (28 isolates) and in 10 from a single blood culture. CNS from paired blood cultures were identified as Staphylococcus epidermidis. Antimicrobial susceptibility was determined and bacteria were typed by pulsed-field gel electrophoresis (PFGE) of bacterial genomic DNA. In 13 patients, the antibiotic susceptibility of isolates was identical. The PFGE patterns from paired blood cultures were identical or closely related in 10 patients, thus confirming the presence of CRBSI. In the remaining four patients they were unrelated, and suggested a mixed infection or contamination. Since CNS isolates from three patients had identical PFGE patterns, they were probably nosocomially spread amongst them.

The Air‐Bubble Method of Locking Central‐Vein Catheters with Acidified, Concentrated Sodium Chloride as a Bactericidal Agent: In Vitro Studies

Soft, cuffed indwelling catheters are used for hemodialysis access and intravenous infusions. The majority of these catheters are removed as a result of infection caused by contamination of the catheter hub during the connection/disconnection procedures. To prevent clot formation in the lumen, these catheters are routinely "locked" with heparin or some other anticoagulant. None of the anticoagulants commonly used as locking solutions demonstrates any significant bactericidal properties. The primary goal of this study was the development of a catheter locking method that retains anticoagulant properties at the catheter tip and bactericidal properties at the catheter hub. The second goal was to find a solution that possesses excellent bactericidal properties but is not detrimental in the event of injection into the patient's blood stream. The bactericidal properties of acidified, concentrated saline (ACS) were compared to concentrated trisodium citrate and to commonly used bactericidal agents such as povidone iodine, sodium hypochlorite, and chlorhexidine. In preliminary studies, the rate of diffusion of solutes was measured in glass tubes. In another set of experiments, the mixing of two solutions (anticoagulant and bactericide) separated by an air bubble ("air-bubble method") was observed in stationary and moving systems. The final series of studies compared the bactericidal properties of ACS to other bactericidal solutions mentioned above. The solutions diffused swiftly in the glass tubes, and by the third day, both solutions were mixed. The air-bubble method prevented mixing in both stationary and moving systems. The bactericidal properties of ACS were superior to all other tested solutions. The proposed method of catheter locking with anticoagulant at the catheter tip and ACS at the catheter hub separated by an air bubble is a promising technique and clinical studies are warranted.

Air‐Bubble Method of Locking Central‐Vein Catheters for Prevention of Hub Colonization: A Pilot Study

The major source of catheter-associated bacteremia is contamination of the catheter hub during connection-disconnection procedures. A new method of catheter locking has been developed wherein anticoagulant is injected first, followed by a 0.1-mL air bubble and 0.9 mL of bactericidal solution. The anticoagulant is then located at the catheter tip and the bactericidal solution is located at the catheter hub. The air bubble prevents mixing of the two solutions. The bactericidal solution was acidified concentrated saline (ACS). The 27% saline solution has a pH of 2.0. ACS was chosen because it is theoretically harmless if injected in the amount used to lock the catheter lumens. The goals of this pilot study were to determine whether the new method of catheter locking is easy to perform with available syringes and whether eventual injection of the experimental solution is well tolerated. Ten patients were randomly assigned, either to heparin lock (5 patients, 62 treatments) or air-bubble method (5 patients, 56 treatments). In the control group, the catheters were locked with heparin, 5000 U/mL. In the experimental group, the catheters were locked with heparin, air bubble, and ACS. Altogether, the lumens were overfilled by 0.2 mL. Compared to the routine method, the experimental method required a 1- to 2-min-longer procedure time. There were no errors in proper sequence of injections into the lumina. There were no episodes of bacteremia related to hub contamination in either group. In the air-bubble group, there was one case of bacteremia associated with purulent drainage from the exit and the same organism in both cultures. In three instances in each group, the locking solution could not be aspirated and was injected without any subjective symptoms or objective signs. We conclude that the air-bubble method of locking central-vein catheters is easy to perform. In three instances of air-bubble and ACS injection, there were no adverse effects. A full-scale prospective randomized study is feasible and warranted.

A needleless closed system device (CLAVE) protects from intravascular catheter tip and hub colonization: a prospective randomized study

Hub colonization and subsequent intraluminal progression due to frequent opening and manipulation of intravenous systems is the cause of many catheter-related infections (CRI). A prospective, comparative, randomized study was performed to assess a new closed-needleless hub device (CLAVE ®) compared with conventional open systems (COS). End-points were hub and skin colonization, catheter tip colonization, catheter-related bloodstream infection (CRBSI) and number of accidental needlesticks. All cultures were processed following standard semiquantitative microbiological techniques. The study involved patients who underwent heart surgery over an 11-month period in a post-surgical ICU. During the study period, 352 patients underwent major heart surgery and 1774 catheters were inserted. Overall, 865 catheters in 178 patients were allocated to the CLAVE system and 909 catheters in 174 patients to COS. The groups were similar regarding underlying conditions and risk factors for infection. Comparison of endpoint results in CLAVE and COS groups was as follows: incidence density per 1000 catheter-days of tip colonization: 59.2 versus 83.6 ( P=0.003); of hub colonization: 7.56 versus 24.66 ( P=0.0017); of skin colonization: 41.5 versus 58.9 ( P=0.038); and of CRBSI 3.78 versus 5.89 ( P=0.4). There was one accidental needlestick and one catheter-related prosthetic endocarditis in the COS group. Multivariate analysis showed that CLAVE use was an independent protective factor for tip colonization. CLAVE offered significant protection from catheter-tip and hub colonization.

Air-bubble Method of Locking Central-vein Catheters: A Pilot Study

The major source of catheter-associated bacteremia is contamination of the catheter hub during connection-disconnection procedures. Between dialyses, the catheter lumens are commonly locked with heparin (H), which does not prevent bacterial growth. Prophylactic use of antibiotics mixed with H reduces bacteremic episodes, but risks the development of antibiotic-resistant strains of bacteria. A new method of catheter locking has been developed (U.S. Patent 6,423,050), wherein anticoagulant is injected first, followed by 0.1 ml air bubble, and a bactericidal solution. The anticoagulant is then located at the catheter tip, where clotting is a problem, and the bactericidal solution is located at the catheter hub, where bacterial contamination is common. The air bubble prevents mixing of the two solutions. A feasibility study has been conducted using H 5,000 units/ml as the anticoagulant, and acidified (pH = 2.0) concentrated (27%) NaCl (ACS) as the bactericidal solution (Twardowski ZJ and Moore HL. Bactericidal properties of acidified (pH 2.0), concentrated (27%) NaCl (ACS), a potentially useful agent for locking hemodialysis catheters. Hemodial Int. Abstracts, 2003; 7: this issue). Ten patients were randomized, either to H lock (5 patients, 62 treatments) or air-bubble method (5 patients, 56 treatments). In the control group the catheters were locked with H according to the capacity provided by the manufacturer with 0.1 ml overfill. In the experimental group, the catheters were locked with H (amount varied according to catheter fill volume), 0.1 ml air bubble, and 0.9 ml ACS. Altogether, the lumen was overfilled by 0.1 ml. According to calculations, an incidental, rapid injection of 0.1 ml air is harmless and rapid injection of up to 1.5 ml of ACS would not perceptibly affect blood pH and/or osmolality in the superior vena cava. The study was approved by the Institutional Review Board of the University of Missouri. There were no problems with locking of the catheters. There were no episodes of bacteremia in either group, except for one case associated with purulent drainage from the exit and same organism in both cultures. In three instances in each group, the locking solution could not be aspirated and was injected without any subjective symptoms or objective signs. We conclude that the air-bubble method of locking central-vein catheters is safe, and a full-scale prospective randomized study is feasible.

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...

A review of risk factors for catheter-related bloodstream infection caused by percutaneously inserted, noncuffed central venous catheters: implications for preventive strategies.

Strategies for preventing central venous catheter (CVC)-related bloodstream infection are most likely to be effective if guided by an understanding of the risk factors associated with these infections. In this critical review of published studies of risk factors for CVC-related bloodstream infection that were prospective and used multivariable techniques of data analysis or that were randomized trials of a preventive measure, a significantly increased risk of catheter-related bloodstream infection was associated with inexperience of the operator and nurse-to-patient ratio in the intensive care unit, catheter insertion with less than maximal sterile barriers, placement of a CVC in the internal jugular or femoral vein rather than subclavian vein, placement in an old site by guidewire exchange, heavy colonization of the insertion site or contamination of a catheter hub, and duration of CVC placement > 7 days. Prospective studies or randomized trials of control measures focusing on these risk factors have been shown to reduce risk significantly: formal training in CVC insertion and care, use of maximal sterile barriers at insertion, use of chlorhexidine rather than povidone-iodine for cutaneous antisepsis, applying a topical anti-infective cream or ointment or a chlorhexidine-impregnated dressing to the insertion site, and the use of novel catheters with an anti-infective surface or a contamination resistant hub. Better prospective studies of sufficient size to address all potential risk factors, including insertion site and hub colonization, insertion technique, and details of follow-up care, would enhance our understanding of the pathogenesis of CVC-related bloodstream infection and guide efforts to develop more effective strategies for prevention.