Central venous catheter infections

Central venous catheter use and the risk of infection in children with acute lymphoblastic leukemia: a report from the Children's Cancer Group

PURPOSE

To describe patterns of central venous catheter (CVC) use and determine the risk of infection associated with a catheter in children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

Children with ALL (n = 1934), participating in Children's Cancer Group studies for good-prognosis ALL (CCG-1881) and intermediate-risk ALL (CCG-1891) were evaluated in a retrospective case-control study. The presence of a catheter and the occurrence of infectious complications were recorded after each treatment phase.

RESULTS

Young age and enrollment in the intermediate-risk study were associated with higher rates of catheter use. During each of the first four phases of therapy, the adjusted risk of infection was two- to fourfold higher when a catheter was in place. The proportion of patients with infection during the first four phases of therapy was 2.6 times higher with a CVC (14.4% versus 5.7%). Catheter use was associated with significantly increased hospitalization rates during induction, consolidation, and interim maintenance, but not during delayed intensification. A catheter did not significantly increase the risk of fever during neutropenia.

CONCLUSION

The presence of a CVC increases the risk of infection during the early phases of low-intensity therapy for ALL.

A new technology of microdispersed silver in polyurethane induces antimicrobial activity in central venous catheters

Metal ions or metal ions in complexes or compounds have been used for centuries to disinfect fluids, solids and tissues. The biocidal effect of silver, with its broad spectrum of activity including bacterial, fungal and viral agents, is particularly well known and the term "oligodynamic activity" was coined for this phenomenon. Silver ions have an affinity to sulfhydryl groups in enzyme systems of the cell wall, through which they interfere with the transmembranous energy transfer and electron transport of bacterial microorganisms. Silver ions also block the respiratory chain of microorganisms reversibly in low concentrations and irreversibly in higher concentrations. Binding to the DNA of bacteria and fungi increases the stability of the bacterial double helix and thus inhibits proliferation. There is no cross resistance with antibiotics and also no induction of antimicrobial resistance by silver ions. The concentrations required for bactericidal activity are in the range 10(-9) mol/l. These concentrations can be achieved in solution by the interaction of metallic silver with electrolytes only if there is a large enough surface of silver. By a novel technology, metallic silver is distributed in submicron particles in polyurethane and results in a concentration of 0.8% in an active surface of 450 cm2/g polyurethane. Polyurethane is hygroscopic and rapidly attracts water; the interaction of electrolyte solutions with the extremely finely distributed silver throughout the polyurethane releases bactericidal concentrations of silver ions over a period of years to the surface of the material. The electronegatively charged surface of bacteria attracts the positively charged silver ions. The concentrations released from the polyurethane are far below the toxic concentrations for humans.

Infection control and outpatient parenteral antibiotic therapy

Outpatient procedures have become more complex, requiring outpatient providers to offer technical procedures in the home, office, and clinic. This shift in health care has brought about the need for staff members to become proficient in a variety of technical procedures that were once done only in the hospital setting. Outpatient i.v. therapy has caused home health care agencies, physicians' offices, and clinics to seek education and training regarding i.v. therapy and to develop basic infection-control guidelines and guidelines related to the insertion and maintenance of i.v. devices. The goals of the outpatient provider are to prevent i.v.-related complications and to provide quality patient care. These can be accomplished by strict adherence to sound infection-control guidelines and routine monitoring of procedure techniques and complications of care. Outpatient providers may wish to seek expertise and guidance from hospital infection-control personnel, infectious diseases specialists, or other infection-control consultants to meet the demands of the complexity of outpatient care.

Nutritional support in malnourished paediatric patients

An imbalance between a person's energy requirements and his or her dietary protein and caloric supply is the source of protein energy malnutrition (PEM), which compounds the problems of any underlying disease. Malnutrition may occur quite rapidly in critically ill patients, particularly those suffering from sepsis, setting up a vicious cycle with worsening of the PEM. This chapter examines the main consequences of PEM, the means whereby appropriate nutrition may be provided, and risks for severely malnourished paediatric patients in hospital. If the gastrointestinal tract can be used for refeeding, it should be used. When the gastrointestinal tract is unable to meet the protein and energy requirements, parenteral nutrition (PN) is required. PN is efficient but carries a high risk of metabolic complications known as the refeeding syndrome and directly related to the homeostatic changes secondary to severe PEM. Catch-up growth may be achieved by using appropriate nutritional support. Changes in body composition have to be assessed during the course of renutrition.

Use of urokinase in pediatric hematology/oncology patients

PURPOSE

This study was conducted to determine urokinase use practices in pediatric hematology/oncology centers.

METHODS

Pediatric hematology/oncology centers were surveyed by telephone regarding urokinase use in children with central venous catheters (CVCs).

RESULTS

A total of 92 centers participated in the study. Urokinase is the primary thrombolytic agent used in pediatric hematology/oncology centers; 67 of 92 (73%) centers had a written protocol for its use. Multiple boluses of urokinase were used in most centers; only 16 of 92 (17%) centers limited urokinase use to 1 bolus per episode of CVC occlusion. At 10 of 92 (11%) centers, adverse events (e.g., fever, chills, or bleeding) after urokinase administration were reported. At 83 of 91 (91%) centers, urokinase was routinely used to clear thrombi in children with central nervous system tumors despite contraindications. At 80 of 92 (87%) centers, occluded CVCs were replaced after unsuccessful thrombolytic therapy, but only 21% of the centers altered the CVC maintenance protocol after replacement. Written protocols, the use of multiple boluses, and urokinase infusions were more likely at larger centers (i.e., > 200 patients) than in medium (100-200 patients) or small (< 100 patients) centers.

CONCLUSIONS

Urokinase is a widely used alternative to replacement of occluded CVCs, but protocols very widely. Indiscriminate urokinase use can be expensive and potentially hazardous. Centers that use urokinase should have standardized protocols, monitor use and adverse effects, and periodically review efficacy data.

Implantable central venous access devices in children with metabolic disease

We have inserted 20 totally implantable central venous devices in 17 patients with severe metabolic disease over a 43-month span. Patient ages ranged from 2 months to 17 years (mean, 4.2 years). The underlying pathology was Gaucher's disease in six patients, vitamin D-dependent rickets type II in five, propionic acidemia in two, and methylmalonic acidemia, 3-hydroxyl-3-methylglutaryl coenzyme A (CoA) lyase deficiency, fructose 1,6 diphosphatase deficiency, and urea cycle disorder in one child each. There were seven complications (six due to catheter-related infection and one due to occlusion of the system) during a total of 7,278 patient-catheter days. The infection rate was 0.8 per 1,000 days. Six catheters were removed due to complications and two due to completion of treatment. There were no operative complications or deaths. Our experience demonstrates that a totally implantable device may be useful in children with metabolic disease who need long-term venous access. Attention should be given to minimize the infection rate to reduce the rate of catheter removal.

Technical aspects of central venous catheterization

Central venous access has been widely used in the treatment of different categories of patients but it is associated with a wide range of complications. Different catheters, approaches and techniques have been employed to minimize those complications related to catheter insertion as well as those related to the prolonged use of catheters. This article reviews the technical aspects of central venous catheterization and associated complications.

Septicemia and septic shock in pediatric patients: 140 consecutive cases on a pediatric hematology-oncology service

PURPOSE

This report describes the incidence of septic shock in pediatric hematology-oncology patients with positive blood cultures and investigates parameters of potential use in early diagnosis of gram-negative (GN) bacteremia and septic shock.

PATIENTS

In a 12-month period, 140 consecutive episodes of septicemia (135 bacterial and 5 fungal) were seen in 100 patients. The absolute neutrophil count (ANC) was > 500/microl in 89 episodes (65%).

RESULTS

Septic shock developed in patients with positive blood cultures with an overall incidence of approximately 19%. Of the 12 bacteremic patients who required transfer to the intensive care unit, 83% had a GN isolate recovered. The incidence of septic shock was not significantly lower in the group of patients with ANC > 500/microl. Low serum bicarbonate correlated with GN infection in patients with bacteremia.

CONCLUSIONS

GN organisms were the major cause of septic shock in a group of pediatric hematology-oncology patients with positive blood cultures although they were recovered less frequently than gram-positive organisms. In our study, non-neutropenic patients with indwelling catheters were at approximately the same risk for GN shock as neutropenic patients. Monitoring blood carbon dioxide content may be useful in the early diagnosis of GN infection.

Sepsis during total parenteral nutrition: exploration of risk factors and determination of the effectiveness of peripherally inserted central venous catheters

BACKGROUND

Sepsis is the most frequent serious complication during total parenteral nutrition (TPN), resulting in increased morbidity, mortality and health care costs. Existing reports have not documented the risk factors of sepsis during TPN. The objectives of this study were to determine the rate of sepsis in our practice and to explore the risk factors for sepsis during TPN. We also determined the role and efficacy of using peripherally inserted central venous catheters (PCVC) as insertion catheters to administer TPN.

METHODS

From October, 1994, to May, 1996, we administered TPN to 378 pediatric patients hospitalized at Mackay Memorial Hospital. We followed all cases for the occurrences of any complications while administering TPN. We studied all patients who had fever, a clinical presentation of sepsis and a positive blood culture during their course of TPN.

RESULTS

During the 20-month period 378 patients received TPN for a total of 6562 days. Fifty-six patients presented with clinical sepsis and positive blood cultures. Significant features in the sepsis group included longer duration of TPN, age < 3 months, usage of central venous catheters, gastrointestinal diseases as indication for TPN, low birth weight and short gestational age in prematurity. Seven patients died despite prompt antimicrobial therapy. One hundred eleven patients received TPN via PCVC for a mean duration of 17.1 days, significantly longer than 10.4 days in the peripheral intravenous catheter group but no difference between the sepsis rates.

CONCLUSION

Considering the high incidence of sepsis during TPN, every attempt should be made to minimize the length of TPN therapy and encourage early enteral feeding. We also recommend the use of PCVC in patients requiring prolonged nutritional support.

Central venous catheter access

Central venous access for the purpose of supplying parenteral nutrition to the pediatric age group requires a careful definition of the patient's caloric need, estimated duration of therapy, and an assessment of available sites. Peripheral vein parenteral nutrition is limited by caloric density of the nutrient fluids, while peripherally inserted central catheters (PICC) offers a new technology for accessing central veins while obviating the risk of central vein access. Routes of central vein access are several and there are also a variety of catheters available for placement. Tunneled percutaneous placement of silicone rubber cuffed catheters via the subclavian vein approach is that technique we use most commonly. The risks of such access catheters include mechanical risks of placement, venous thrombosis of the access sites, and most importantly catheter related infections, either at the exit site, the subcutaneous tunnel or pouch, or even generalized sepsis. With a full knowledge of the spectrum of access techniques, access materials, and risks, safe total parenteral nutrition can be safely delivered to the children in need.

Central venous catheter-related septicaemia in paediatric cancer patients

A prospective study of septicaemia, with special reference to central venous catheter (CVC)-related septicaemia, was performed over a nine-month period in paediatric cancer patients undergoing anti-neoplastic therapy. A total of 142 patients with 153 CVCs were included in the study. Seventy-two episodes of septicaemia were detected in 66 patients; overall, 46% of patients developed one or more episodes of septicaemia. Thirty-nine (54%) of these episodes occurring in 34 patients were CVC-related. Twenty-one (29%) of the episodes occurring in twenty patients were probably unrelated to CVCs and 12 (17%) episodes in 12 patients were of uncertain source. A total of 22932 CVC days were studied. The rate of CVC-related septicaemia was 1.7 episodes/1000 catheter days. Gram-positive organisms were commonest, causing 34 (87%) episodes of CVC-related septicaemia. Twenty-five (71%) of 35 evaluable episodes were successfully treated with antibiotics without CVC removal. Two patients died, CVC related sepsis probably contributing to death, and one patient suffered prolonged morbidity associated with CVC sepsis. Gram-negative organisms were the commonest cause of CVC-unrelated septicaemia, being implicated in 13 (62%) episodes.

Efficacy of a vancomycin solution to prevent bacteremia associated with an indwelling central venous catheter in neutropenic and non-neutropenic cancer patients

We evaluated the efficacy of a vancomycin solution in the prevention of bacteremia caused by vancomycin-sensitive organisms (VSO) in cancer patients with a tunneled central venous catheter (CVC). Eighty-three patients who had a single lumen CVC were randomized to use a heparin solution (25 U/ml) for daily catheter flush with (HepVan) or without (Hep) vancomycin, 25 mcg/ml. Febrile episodes were recorded, and central and peripheral blood cultures were drawn before beginning antibiotic therapy. Patients participated in follow-up to 16,677 catheter days (8,666 Hep and 8,011 HepVan), and 143 febrile episodes were recorded (82 Hep and 61 HepVan). Forty-four episodes of bacteremia occurred, 23 of them due to VSO (16 occurred in the Hep group and 7 in the HepVan group (P = 0.19). VSO bacteremia occurred in 14 neutropenic (absolute neutrophil count < 500 x 10(9)/l) episodes (7 Hep vs. 7 HepVan) and in 9 non-neutropenic episodes (9 Hep vs. O HepVan; P = 0.013). Vancomycin effectively prevented bacteremia by VSO in non-neutropenic patients, supporting the idea that intraluminal colonization of indwelling CVCs contributes to bacteremia only in these patients.

Bloodstream infections in home infusion patients: the influence of race and needleless intravascular access devices

OBJECTIVES

To determine the cause of increased central venous catheter-associated (CVC) bloodstream infection (BSI) rates in a cohort of pediatric hematology /oncology patients receiving home health care (HHC).

METHODS

A retrospective cohort study of hematology/oncology patients with CVCs receiving HHC from January 1992 through November 1994.

RESULTS

Of 182 patients with CVCs identified during the study period, 58 (32%) acquired 90 BSIs during 75,085 CVC days. BSI rates increased significantly from 1992 through 1994 (0.8 vs 1.0 vs 1.7 BSIs per 1000 CVC days; p < 0.005). Known risk factors, including catheter type, patient age less than 5 years, sex, or diagnosis, were not associated with increased BSI rates. After introduction of needleless devices for CVC access to the HHC regimen in May 1993, BSI rates increased 80% (from 0.81 to 1.46 BSIs/1000 CVC days, relative risk 1.8; p < 0.02). The only other significant risk factor was the race of the patient. White children had the lowest BSI rate before and after needleless-device introduction (0.4 vs 0.9 BSIs/1000 CVC days; p > 0.1), whereas black patients had the highest, unaffected by the introduction of these devices (2.5 BSIs/1000 CVC days). Both Hispanic (0.5 vs 1.6 BSIs/1000 CVC days) and Asian-American children's (0.4 vs 1.5 BSIs/1000 CVC days) BSI rates increased threefold and fourfold after the introduction of needleless devices.

CONCLUSIONS

Our data suggest that pediatric hematology/oncology patients receiving HHC via needleless devices may have an increased risk of BSIs, and this risk may vary by race. We hypothesize that prevention of BSIs may require consideration of cultural, ethnic, and language differences when parents are trained to provide care for their children with CVCs in the home.

[Clinical, pharmacokinetic and therapeutic study of amikacin with single daily dose and in combination in neutropenic children with fever]

BACKGROUND

The efficacy of single daily dose of amikacin has been recently demonstrated in neutropenic children with fever.

POPULATION AND METHODS

Eighteen children aged 1 to 15 years were included in the study. All patients were febrile and granulocytopenic and had indwelling intravenous catheter. Amikacin was administered as a 30-minute intravenous infusion once daily (20 mg/kg on day 1, then 15 mg/kg) for 3 to 30 days; the patients received amikacin in combination with piperacillin and vancomycin. Serum levels of amikacin were measured on days 1, 3, 6 and 10, and 30 min, 60 min and 180 min after the end of the infusion.

RESULTS

All patients responded favourably to the antibiotic therapy. Sixty-two kinetics were performed: peak amikacin concentrations measured (30 min after 30-min infusion) on day 1 averaged 43.7 micrograms/mL (+/- 13.8). A significant increase in peak serum concentrations was observed during the treatment (day 3 vs day 10) without change in the trough serum concentrations. The volumes of distribution were considerably important in these granulocytopenic children and there was a large inter and intra-patient variability; the elimination half-life of the amikacin was short (1.45 h). There was no significant nephrotoxicity in any patient.

CONCLUSION

The use of single daily dose amikacin in combination with a broad spectrum beta-lactam antibiotic and vancomycin was efficient and safe in febrile granulocytopenic children. The simulation of the amikacin behaviour in the deep compartment should be evaluated; in fact, it might reflect better accumulation of the drug than serum concentrations.

Migration of jugular or subclavian venous catheters into inferior tributaries of the brachiocephalic veins or into the azygos vein, with possible complications

Six children are reported in whom a central venous catheter from the internal jugular or the subclavian vein migrated to an anomalous position: the left superior intercostal vein in the first two cases, the thymic vein in the third, and the azygos vein in the last three. Resultant complications in five cases were: extravasation of the infusate in the first and third case; local vascular stenosis or complete vascular occlusion in the second and fifth case; and obstruction of the azygos arch due to local thrombosis and possible stenosis, with a likely extravasation of the infusate, in the sixth case. The mediastinal vascular anatomy related to these central venous catheters is reviewed with reference to similar and related cases in the literature.

Yield of positive blood cultures in pediatric oncology patients by a new method of blood culture collection

BACKGROUND

The optimal number of blood cultures and the volume of blood for pediatric blood cultures have not been defined. In 1990 such criteria were established at our institution. We retrospectively reviewed records of all pediatric oncology patients who were admitted for febrile episodes in 1989 and in 1991 and 1992 to determine whether there was an increase in the detection of bacteremia and fungemia.

METHODS

Blood was drawn via venipuncture and central intravascular catheters and inoculated into the designated blood culture bottles. Each patient had a minimum of two separate blood draws, i.e. two separate cultures; the volume was determined by the patient's weight. In all cases < 1% of the patient's blood volume was drawn per culture. Patients' records were reviewed regarding type of malignancy, chemotherapy and neutropenia.

RESULTS

The rate of bacteremic patients increased from 12% (13 of 113) in 1989 to 22% (27 of 123) in 1991. This increase continued through 1992 with 23% (27 of 118) of patients having positive blood cultures. Gram-positive bacteria predominated throughout the study period.

CONCLUSIONS

Although factors such as more aggressive chemotherapy or a different spectrum of malignant diseases may contribute to the statistically significant increase in identification of bacteremic patients, a standardized method of blood culture collection is merited. The consistent volumes of blood per culture and the minimum of two cultures per febrile episode follow the principles of blood culture collection established for adults. The same principles should apply to pediatric patients.

Six years' experience of total parenteral nutrition in children with hematological malignancies at a single center: management, efficacy, and complications

Total parenteral nutrition (TPN) is an important issue in supportive care of children with leukemia. We studied 131 consecutive children (87 male, 44 female) with hematological malignancies who received TPN at our center from July 1984 to July 1990 with the aim of evaluating the efficacy and complications of TPN. The use of TPN was associated with lack of any alteration of the anthropometric indexes used in this study. The complications were prevalently metabolic, generally mild, and easily controlled. Laboratory monitoring of nutritional status during TPN is probably of little value in this setting. The feasibility of in-ward preparation of TPN by nurses makes TPN possible at low cost provided that patients are selected carefully.

Urokinase in the treatment of bacteremia and candidemia in patients with right atrial catheters

BACKGROUND

Urokinase plasminogen activator was used in combination with antibiotic therapy given through the catheter to improve the treatment of right atrial catheter infections.

METHODS

One hundred fifty-four episodes of bacteremia and candidemia occurring in 97 children with malignant or hematologic conditions were treated. After 24 hours of antibiotic therapy, 1 ml urokinase (5000 units/ml) was instilled, dwelling 1 hour, and then removed; this was repeated within 24 hours. Antibiotic therapy was continued for then removed; this was repeated within 24 hours. Antibiotic therapy was continued for 10 to 35 days. Administration of urokinase was repeated once if infection recurred within 8 weeks of initial treatment.

RESULTS

There were no adverse affects from administration of urokinase. Bacteremia clearance failed after initial administration of urokinase in 12 episodes; this failure was mostly associated with the presence of gram-positive organisms. Blood culture results remained positive in three cases after repeat therapy. Bacteremia recurred in 15 of 125 episodes; in three cases bacteremia did not clear after repeat administration of urokinase or recurred again. Recurrence was lowest for gram-negative organisms and Candida sp. Less than 5% of catheters were removed as a result of treatment failure.

CONCLUSIONS

Administration of urokinase combined with antibiotic therapy is safe and may be effective in treating bacteremia and candidemia in patients with right atrial catheters. Use of urokinase may improve treatment of organisms that are otherwise difficult to control and may prevent recurrence of infection.

Central venous catheter tip position and malfunction in a paediatric oncology unit

An audit of 151 central venous catheters (CVCs) in 118 children with malignant disease was carried out over 20 months. The types included 31 valved silastic (Groshong), 58 non-valved silastic (Hickman), and 62 non-valved polyurethane (Cuff Cath) CVCs. There was no difference between the three groups with regard to the clinical diagnosis. The mean patient age at catheter insertion was 5.5 years and the mean weight 21.6 kg. None of the catheter types were associated with an increased risk of problems at insertion, migration, mechanical damage, blockage, sampling, or catheter infection. The incidence of catheter infection was 1.4/1,000 catheter days. Exit-site infection was less frequent with Groshong CVCs (P <0.05), which were in situ for the shortest period. The risk of problems with blood sampling was significantly increased in those catheters whose tip was sited outside the right atrium (P <0.005). For the 60 CVCs removed electively, the mean duration in situ was similar for all catheter types; 43 were removed following a problem. Of these, Groshong catheters were in situ for the shortest period (P = 0.05), probably as a result of delayed anchoring of the cuff. The tip position was the single most important determinant in the correct functioning of CVCs, irrespective of the type of catheter. Intraoperative screening of the tip position at catheter insertion is therefore mandatory for optimal catheter functioning.

Totally implantable vascular access devices in 131 pediatric oncology patients

The use of totally implantable vascular access devices (TIVAD) has gained acceptance in oncology patients, with lower overall complications and maintenance costs than percutaneous silastic catheters. We inserted 135 TIVAD in 131 selected pediatric oncology patients (mean age 8.9 years) for chemotherapy of 68 solid tumors, 39 leukemias, and 24 lymphomas. Patients were required to have an absolute neutrophil count of 1,000/μl prior to TIVAD insertion. The cumulative duration of access was 45,098 days, with a mean of 334 days per device (range 5 to 981 days). At the time of review, 53 (39%) TIVAD were functioning without complication, 69 (51%) were removed at the end of therapy or were functioning at the time of death, and 13 (9.6%) were removed due to complications. Complications (n = 23) included 12 episodes of septicemia and 4 pocket infections for an infection rate of 11.8% (1 in 2,819 access days). Infections were more common in patients with leukemia compared to all others (P <0.001). Coagulase-negative staphylococci were isolated in 10 of the 16 infections; 7 infections resolved with antibiotic therapy. Mechanical complications were associated with 7 (5.2%) devices (1 in 6,443 access days). These data suggest that in selected non-neutropenic pediatric oncology patients, TIVAD can be utilized with minimal morbidity in the delivery of long-term chemotherapy.

"In-situ" Teicoplanin for central venous catheter infection

Infection of central venous catheters (CVC) is a relatively common occurrence in immunocompromised patients, management of which has included I.V. antibiotics +/- removal of catheter. We have previously demonstrated that intracatheter administration of Amikacin empirically, successfully eradicated all bacterial infections except those due to S. epidermidis. A study was subsequently undertaken to treat gram positive cocci infections of CVC with intracatheter Teicoplanin. Eleven patients attending a single institution with documented gram positive cocci infection of CVC over a one year period were included in the study. Teicoplanin was instilled with heparinised saline once daily into the infected lumen of the CVC and allowed to remain for 24 hours. Treatment was continued for 48 hours after negative cultures were reported. Teicoplanin was successful in eradicating infection in 100% of cases. Mean duration of treatment was six days (range 4-9 days). Four patients subsequently developed a further infection, a mean of 13 weeks from first infection, only one of which was due to the same organism and this was successfully treated by a further course of Teicoplanin. No side effects were reported and catheter life was prolonged a mean of 132 days after completion of treatment. The use of Teicoplanin in this way for treatment of gram positive cocci infection of CVC is highly effective; once daily administration of antibiotic enables treatment to be given on an outpatient basis, thereby minimising hospital admission.

Morbidity using subcutaneous ports and efficacy of vancomycin flushing in cancer

An evaluation of totally implanted venous access systems inserted in 163 consecutive children with cancer is reported. From 1988 to 1994, 180 subcutaneous ports were inserted in children more than 1 year old. Initial diagnosis was acute leukaemia (n = 79), non-Hodgkin's lymphoma (n = 33), and solid tumour (n = 51). Median age was 85 months. All venous procedures were performed through the device. Chemotherapy was either moderate (n = 13) or intensive (n = 119) or very intensive (n = 48), including 16 patients undergoing marrow transplantation. Cumulative venous access totalled 55,770 patient days with a mean of 305 days/subcutaneous port. The cause of device removal was, end of treatment (n = 111), death due to malignancy (n = 20), catheter related infection (n = 7), and occlusion of the system (n = 4). Mechanical complications occurred in 19 ports; 16 were due to clots, of which 14 were cleared with instillation of urokinase. Documented infectious episodes occurred in 47 ports, recurred once in 14, and twice in five cases. Among these infections, 47 were septicaemic; 31 due to Staphylococcus epidermidis. Twenty seven of initial septic episodes were considered to be catheter related; the rate was 15%/subcutaneous port or 0.05/100 catheter days. Risk factors for the development of a first infection were age below 4 years and the time of use. Since February 1993, vancomycin (50 micrograms/ml) has been given and this has reduced the rate of S epidermidis infection from 26/83 subcutaneous port to 4/97. Life table analysis showed that the infection free interval for staphylococcus was significantly better after this technique ws initiated (log rank rest=0.02). Time saved was approximately 30minutes/patient/week compared with external catheters, or 45 hours/month for the cohort of children treated. Subcutaneous ports in paediatric cancer patients are reliable, safe, and durable and may offer an attractive alternative to external catheters for prolonged venous access and intensive treatment.

Role of catheter colonization and infrequent hematogenous seeding in catheter-related infections

Adult cancer patients were prospectively studied to determine the relationship between ultrastructural and microbiologic catheter colonization and clinical catheter-related infections. Participants included 38 patients whose central venous catheters were removed because of suspected catheter infection (16 patients) or other noninfectious causes (22 controls). The presence of clinical infection was determined. Catheters were examined by microbiologic methods (sonication and roll-plate culture) and by scanning and transmission electron microscopy. Ultrastructural microbial colonization and biofilm formation were universal and occurred as early as one day after catheter insertion. The extent of biofilm formation was unrelated to the clinical status of patient or the catheter microbiological findings. Secondary seeding of catheters was rarely seen. Catheter microbial biofilm formation occurs early, is universal and does not necessarily represent an infectious condition.

Central venous catheter practices: results of a survey

BACKGROUND

The incidence of nosocomial bloodstream infections has increased twofold to threefold in the past decade, and central venous catheter infections account for about 90% of catheter-related nosocomial bloodstream infections. Many studies of risk factors for central venous catheter complications have been conducted, resulting in recommendations for preventive strategies, but few data are available regarding the frequency with which such strategies are employed in clinical practice.

METHODS

A survey was conducted of persons attending a meeting of the National Association of Vascular Access Networks in New Orleans on September 25, 1992. The survey contained 15 questions related to central venous catheters regarding infection control measures, measures to maintain patency, and use of the catheter for obtaining blood specimens for diagnostic tests.

RESULTS

Ninety-two persons from 24 states completed the questionnaire as representatives of 23 teaching hospitals, 21 nonteaching hospitals, and 48 home health agencies. Transparent dressings were used more frequently (88%) than cotton gauze (27%). Alcohol and povidone-iodine solutions were the most frequently used antiseptics. Antimicrobial ointment was used by fewer than half; of these 86% used povidone-iodine and 26% used polymyxin-neomycin-bacitracin. Heparin flushes were still being used by 97% to maintain patency. Most (82%) used central venous catheters to draw blood cultures; of these, 68% drew only qualitative cultures and 32% drew quantitative cultures in addition to or instead of qualitative cultures.

CONCLUSIONS

Significant diversity of practice was documented among the health care organizations represented in this survey. Some of the practices documented in this survey have been associated with higher rates of bloodstream infection; this may partially explain the observed increase during the past decade in the incidence of nosocomial bloodstream infections.

Percutaneous translumbar central venous catheter in infants and small children

Vascular occlusion is a common clinical problem in children dependent on prolonged vascular access. As an alternative to conventional central venous catheter placement we report our experience of four children receiving translumbar inferior vena cava catheter on 12 different occasions. All catheter placements were successful. No procedure-related complications occurred. The median catheter patency was 4.8 months (range 1-10 months). The translumbar route for central venous access is safe and reliable and should be considered when prolonged use is anticipated in infants and small children.

Guidelines for good practice in central venous catheterization. Hospital Infection Society and the Research Unit of the Royal College of Physicians

Central venous catheters (CVC) are commonly used in clinical practice and are associated with several complications, including early and late onset infection. In these guidelines, an outline of good practice for the use of CVC and the prevention of associated infections is presented. Definitions of both localized and systemic catheter-related sepsis are given. Subsequent good practice in relation to the insertion of CVC, including patient preparation, planned duration of catheterization, catheter materials and design of the CVC, are presented. Skin fixation and insertion site care, including the use of dressings and administration sets, as well as an approach to flow obstructions, are also reviewed. The clinical and microbiological diagnosis of catheter-related sepsis and its treatment is next presented. Finally, guidelines for CVC removal and replacement are given. The guidelines are designed to facilitate the development of good practice in the use of CVC, allowing appropriate protocols to be formulated and to reduce infection risk.

230 patient years of experience with home long-term parenteral nutrition in childhood: natural history and life of central venous catheters

The records of 27 pediatric patients who required parenteral nutrition (PN) for 5 to 14.5 years (mean +/- SD, 8.5 +/- 3.8) were analyzed to determine the frequency of complications with their central venous catheters (CVC). This represents a 230 patient-year experience. Patients with short bowel syndrome and chronic intestinal pseudoobstruction syndrome (CIPS) accounted for all but two of the patients. Unsuccessful medical management of the exit site or CVC infection was responsible for removal of 62% of the 123 CVCs. Ninety-five episodes of line infection occurred in 24 patients. Fifty (52%) were successfully treated without catheter removal. The organisms responsible for catheter removal were fungal (14), mycobacterium species (5), gram-positive cocci (22), or gram-negative bacilli (19). The CVCs were infected an average of once every 884 days. The life of the second CVC (23.5 +/- 17.9 months) was significantly longer than that of the first (P < .05). Clotting of the CVC with unsuccessful lysis of the clot was responsible for removal of 24%, and breakage or unsuccessful repair was responsible for 14%. In no patient were all possible venous sites for CVC placement exhausted. Patients with CIPS had substantially fewer catheter complications (P < .05) than did those with short bowel syndrome. In conclusion, CVCs can "survive" without major complications for more than a decade. Numerous factors contribute to the increased rate of CVC survival over time, including improvement in PN self-care with greater experience, improvement in teaching, regular follow-up of patients, better management of infection, and better ability to treat CVC thrombosis or breakage.

Subcutaneous infusion ports in the pediatric patient with hemophilia

Central venous access devices have become important tools in the management of pediatric patients with malnutrition, malignancy, and infections requiring long-term antibiotic treatment. Hemophilia presents a lifetime challenge for venous access and at times can be an urgent or life-threatening situation. Since 1986, the authors have implanted 11 subcutaneous infusion ports in nine patients with hemophilia. The systems have remained in place for up to 7 years, without major complications or problems. Two catheters were replaced, after 4 and 6 years, because of skin erosion and blockage, respectively. One catheter was removed after 7 years because of blockage following local trauma and was not replaced. A recent survey through the Canadian Hemophilia Centre Directors Group obtained a further 45 subcutaneous infusion ports in other centers across Canada. The benefits of this system are overwhelming enthusiasm by the parents and children and no major complications. Some of the patients are now HIV-positive and are able to use their system for ongoing drug therapy.

Adhesion of coagulase-negative staphylococci and adsorption of plasma proteins to heparinized polymer surfaces

Protease treatment of cells of coagulase-negative staphylococci reduced the adhesion of bacteria to heparinized polyethylene preadsorbed with serum. Fibronectin (Fn), fibrinogen (Fg), vitronectin, complement factor C3c, plasminogen, laminin and to a low extent albumin were detected on tridodecylmethylammonium chloride (TDMAC)-heparinized polyvinyl chloride (PVC) catheters extirpated from the circulation of patients. Using a perfusion model we show that during the first hours of perfusion with human plasma, Fn and Vn dominate, whereas after 22 h of perfusion Fg is the dominant protein. Field emission scanning electron microscopy and atomic force microscopy studies on TDMAC-heparinized catheters as well as on end-point attached heparinized PVC catheters indicate that quantitatively more Fg than Fn is exposed on these surfaces after prolonged exposure (> 22 h) to human plasma.

Catheter-related infections associated with home parenteral nutrition and predictive factors for the need for catheter removal in their treatment

The inpatient and outpatient records were reviewed for 527 patients, including 138 children, who were discharged on home total parenteral nutrition and followed by the University of California, Los Angeles, home total parenteral nutrition service for a minimum of 1 week between April 1973 and October 1991. The total follow-up time was 1154 patient years; the median follow-up time was 206 days (range 7 to 6344 days). Thirty-six patients were followed for more than 10 years (median 12.7 years). Three hundred fifteen adults (but only four children) were never infected. A total of 427 catheter-related infections occurred, giving an overall infection rate of 0.37 per patient year (0.51 per patient year in children and 0.28 per patient year in patients followed for more than 10 years). Seventy percent of the infections overall were sepsis (0.26 per patient year); of those, 17% were exit site (0.06 per patient year), and 2% were tunnel (0.01 per patient year) infections. In children, 67% of the infections were sepsis (0.37 per patient year) and 24% were exit site (0.13 per patient year). Fifty-four different organisms were responsible, and 12% of the infections were polymicrobial in origin. Sixty percent of sepsis in all patients was caused by Gram-negative organisms (44% of the catheters were removed). Forty-three percent of sepsis in children was caused by Gram-negative organisms. Twenty-six percent of sepsis in all patients was caused by Gram-positive organisms (40% of the catheters were removed). Thirty-six percent of sepsis in children was caused by Gram-positive organisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Skin versus hub cultures to predict colonization and infection of central venous catheter in intensive care patients

Central venous catheters (CVC) are an important source of nosocomial infection in intensive care units. The unnecessary removal of CVC suspected to be infected can probably be minimized. In order to test the accuracy of non-invasive methods for predicting catheter colonization, we prospectively compared the results of 50 consecutive CVC tip cultures, with cultures of the CVC hub and the skin at the insertion site. The CVC were separated into two groups based upon the underlying reason for CVC removal: group I (n = 20), suspicion of infection; group II (n = 30), no suspicion of infection. The skin culture (with a threshold of 15 CFU) was useful in both groups for assessing catheter colonization since it was always positive in cases of catheter colonization and always negative in the absence of catheter colonization. The contribution of the CVC hub cultures alone was minimal since there was no case of catheter colonization with negative skin cultures and positive hub cultures suggesting that the main route of catheter colonization was via the skin. Catheter-related bacteremia was identified in seven patients (six in group I and one in group II). In these patients, the ratio of bacterial colony counts (central/peripheral) was greater than 10:1 in only two cases.

The effects of electric current on bacteria colonising intravenous catheters

The effect of a direct electric current (10 microA) on the growth of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis was investigated. When the ends of negatively-charged intravascular catheters were placed in nutrient agar seeded with bacteria, circular zones of inhibition of bacterial growth were observed around the catheters. The zones ranged from 6 to 16 mm in diameter according to the organism under test. Zones of inhibition were not produced around positively-charged catheters. Bacteria colonising the surfaces of catheters were similarly affected by the application of a 10 microA electric current. A negative electric current applied to colonised catheters for 4 to 24 h significantly reduced the number of adherent viable organisms as compared to controls. The results demonstrated that a constant electric current of low amperage might be used to reduce bacterial colonisation of intravascular catheters. This may offer a novel means of protecting catheters and other prosthetic devices from associated sepsis in vivo.

Exit site purse-string suture to secure long-term venous catheters

A new method for the prevention of accidental dislodgment of long-term venous catheters involves the use of an exit site purse-string suture that holds the catheter cuff in place before the ingrowth of fibrous tissue. This method is safe, reliable, easily reproduced, and does not require any additional incisions or anchoring devices. In our clinical practice, it has drastically reduced the number of accidental dislodgments.

Pathogenesis of infections related to intravascular catheterization

Over the past few decades, there have been major technological improvements in the manufacture of intravenous solutions and the manufacture and design of catheter materials. However, the risk of infection in patients receiving infusion therapy remains substantial, in part because of host factors (for example, increased use of immunosuppressive therapy, more aggressive surgery and life support, and improved survival at the extremes of life) and in part because of the availability of catheters that can be left in place for very long periods. Microbial components of normal skin flora, particularly coagulase-negative staphylococci, have emerged as the predominant pathogens in catheter-associated infections. Therefore, efforts to prevent skin microorganisms from entering the catheter wound (such as tunnelling of catheters and use of catheter cuffs and local antimicrobial agents) are logical and relatively effective. The specific properties of microorganisms that transform normally harmless commensals such as coagulase-negative staphylococci into formidable pathogens in the presence of a plastic foreign body are being explored. For example, Staphylococcus epidermidis elaborates a polysaccharide adhesin that also functions as a capsule and is a target for opsonic killing. However, the interactions between microorganism and catheter that lead to adherence, persistence, infection, and dissemination appear to be multifactorial.

Persistent catheter-related bacteremia: clearance with antibiotics and urokinase

A patient with terminal osteogenic sarcoma and catheter-related coagulase-negative staphylococcal bacteremia was treated with vancomycin and blood cultures were positive for 4 days documented with quantitative colony counts. Urokinase therapy was initiated and was associated with a transient bacteremia with markedly increased colony counts of coagulase-negative Staphylococcus prior to eradication of the catheter-related infection. We feel that the combination of urokinase and appropriate antibiotics may be an effective method to eradicate line-associated coagulase-negative staphylococcal infection in selected patients.

Volume of blood required to obtain central venous catheter blood cultures in infants and children

To determine how much blood must be discarded before one can obtain a reliable central venous catheter blood culture, we prospectively cultured the blood (from 96 patients) that is ordinarily discarded before obtaining blood for such a culture. We then compared the prospective culture results with those of the actual blood culture. Three sequentially drawn aliquots of blood were aspirated from the central venous catheter and cultured. The culture results of the second aliquot were comparable to those of the third (the portion usually cultured) in overall sensitivity (94.4%), specificity (94.9%), and positive predictive value (80.9%). Thus, the amount of blood that must be discarded (infants: 0.3 mL; children: 1.0 mL) before one can obtain an accurate central venous catheter culture is less than was previously thought.

Prospective analysis of urokinase in the treatment of catheter sepsis in pediatric hematology-oncology patients

Use of right atrial catheters (RACs) in children with cancer improves the comfort and efficacy of therapy. However, catheter-related infections are responsible for significant morbidity leading to the removal of approximately 20% of implanted RACs. Sepsis has been linked to thrombus and fibrin sheath formation within the RAC. Gram-negative and fungal infections appear to be particularly resistant to antibiotic therapy alone and most of these infections have required catheter removal. Urokinase has been effectively used for reopening thrombus occluded RACs. Theoretically, thrombolytic agents could improve the treatment of catheter-related infections by removing luminal sites of bacterial/fungal colonization. We prospectively monitored the use of urokinase and antibiotics for catheter-related sepsis in our pediatric hematology/oncology population from 1985 to 1991. Sepsis episodes were treated with 2 doses of urokinase and antibiotics (10 to 42 days) infused through the RAC. One to 2 mL of urokinase (5,000 U/mL) was instilled in the RAC for 1 hour, then removed and repeated 24 hours later. During the study, 224 RACs were placed in 177 children. RACs were in place for a total of 71,134 days (median, 274 days). There were 67 blood culture-positive sepsis episodes occurring in 50 RACs. Fifty-nine sepsis episodes were treated with urokinase and antibiotics and all responded by clearance of organisms from the blood. Three patients (5.1% of urokinase treated) had recurrent sepsis with the same organism within 2 months, were considered treatment failures and had RACs removed. Only 1 of 16 episodes of multiple organism/Candida sepsis led to RAC removal due to inability to cure the infection.(ABSTRACT TRUNCATED AT 250 WORDS)