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Evaluation of infectious complications of the implantable venous access system in a general oncologic population

      Abstract

      Objectives: This study was conducted to evaluate the infectious morbidity associated with 2 common types of implantable port systems used in a cancer center in Taiwan. Methods: This study is retrospective and descriptive. Five hundred seventy-two patients who received implantable ports at the cancer center between January 1994 and December 1998 were included. The following 4 types of catheter-related infections were defined in this study: bloodstream, pocket, exit-site, and tunnel. Semiquantitative methods (rolling plate) were used for cultures of removed catheters. Results: The average duration for ports after placement in patients was 358 days (range, 1-1742 days), and the median duration was 242 days. The port-related infection rate was 5.6% in 586 ports and 0.15 per 1000 device-days. Our data indicate that when a port is in use, more frequent dressing changes of the needle exit site (every 3 days vs every 7 days) appear to have no significant impact on the catheter-related infection rate (5.2% vs 7.3%, P =.3). Our observation also indicates that if the catheter is used for total parenteral nutrition (TPN), the patient has a significantly increased chance of developing an infection from the Candida species (71% vs 8%, P =.005). Furthermore, the catheters associated with infections caused by the Candida species had a shorter catheter life (median, 44 days). Conclusions: Infection is the most common complication of venous port system use among cancer patients. According to our data, it is safe and cost-effective to change exit-site needles and transparent dressings every 7 days. It is clearly demonstrated by our study that patients with ports used for the administration of TPN had a significantly greater chance of developing infection from the Candida species. Further investigation is needed to compare the relative advantages of using ports versus other devices for the administration of TPN in cancer patients. (Am J Infect Control 2003;31:34-9.)
      The need for intravenous access devices for the administration of cancer therapy has increased proportionately with the increasing number of patients diagnosed with cancer. To have a reliable venous access for the delivery of therapeutic agents was particularly problematic until long-term venous devices became available.
      • Lambert ME
      • Chadwick GA
      • McMahon A
      • Scarffe JH
      Experience with the Port-a-Cath.
      • May GS
      • Davis C
      Percutaneous catheters and totally implantable access systems: a review of reported infection rates.
      Most chemotherapy agents irritate the veins and may cause phlebitis and eventual obliteration of peripheral veins. If extravasation of vesicant agents occurs, the surrounding tissue may have a serious reaction, which may eventually lead to tissue damage and infection. The development of the implantable port has provided for a more reliable and convenient access for administering various therapeutic agents in cancer patients.
      • May GS
      • Davis C
      Percutaneous catheters and totally implantable access systems: a review of reported infection rates.
      • Strum B
      • McDermed J
      • Korn A
      • Joseph C
      Improved methods for venous access: the Port-a-Cath, a totally implanted catheter system.
      • Carde P
      • Cosset-Delaigue MF
      • Laplanche A
      • Chareau I
      Classical external indwelling central venous catheter versus totally implanted venous access systems for chemotherapy administration: a randomized trial in 100 patients with solid tumors.
      • Barrios CH
      • Zuke JE
      • Blaes B
      • Hirsch JD
      • Lyss AP
      Evaluation of an implantable venous access system in a general oncology population.
      • Sinoff CL
      • Koski T
      Port-a-Cath in cancer patients.
      • Wesenberg F
      • Flaatten H
      • Janssen CW
      Central venous catheter with subcutaneous injection port (Port-a-Cath): 8 years clinical follow up with children.
      • Poorter RL
      • Lauw FN
      • Bemelman WA
      • Bakker PJM
      • Taat CW
      • Veenhof CHN
      Complications of an implantable venous access device (Port-a-Cath) during intermittent continuous infusion of chemotherapy.
      • Kock HJ
      • Pietsch M
      • Krause U
      • Wilke H
      • Eigler FW
      Implantable vascular access systems: experience in 1500 patients with totally implanted central venous port systems.
      A further advantage of the implantable port is that it requires minimum care and maintenance when it is not in use. However, complications from the use of implantable ports do occur, with one of the most common being infection.
      • Kock HJ
      • Pietsch M
      • Krause U
      • Wilke H
      • Eigler FW
      Implantable vascular access systems: experience in 1500 patients with totally implanted central venous port systems.
      • Schwarz RE
      • Groeger JS
      • Coit DG
      Subcutaneously implanted central venous access devices in cancer patients: a prospective analysis.
      • Ballarini C
      • Intra M
      • Pisani Ceretti A
      • Cordovana A
      • Pagani M
      • Farina G
      • et al.
      Complications of subcutaneous infusion port in the general oncology population.
      Numerous studies have focused on evaluating the short-term complications of the devices. However, the long-term complications, particularly the infectious morbidity, have not been carefully evaluated. To prevent infections is essential in caring for cancer patients because most of them are immunocompromised during the disease course. Infections that develop during the course of treatment not only may result in longer hospital stays but also may increase health care costs. This study evaluates the infectious morbidity associated with 2 common types of implantable port systems used in our institution—an established oncology center in Taiwan.

      Patients and methods

      This study is retrospective and descriptive. Five hundred seventy-two patients who received implantable ports for the management of cancer at the Sun Yat-Sen Cancer Center between January 1994 and December 1998 were included. Patients who were not treated or followed-up by our center were excluded. The χ2 test was used to compare the difference between groups.
      The following 2 types of ports were used: (1) the Port-a-Cath (Pharmacia Implantable Access Systems, St. Paul, Minn), which is a stainless titanium portal with an internal volume of 0.5 mL that connects to a radiopaque silicone rubber catheter, and (2) the MRI port (Bard Access Systems, Salt Lake City, Utah), which is a plastic rubber portal with an internal volume of 0.5 mL and a silicone septum that is connected to a silicone Groshong catheter (a closed-system catheter with a 3-way valve that allows infusion and blood aspiration while reducing blood reflux and clotting).
      When ports were used, nurses adhered to our standard protocol for exit-site care, the transparent dressing of needle-insertion site, and administration set change. If ports were used at home, the home care nurse adhered to the same protocol for care and maintenance of the ports. Data, therefore, were stratified into the 2 following groups according to different protocols developed during the study period for comparing infection rate: the first group included patients whose ports were removed between January 1994 and July 1995 and whose access needles and intravenous administration sets were changed every 3 days, and the second group included patients whose ports were removed between August 1995 and December 1998 and whose access needles and intravenous administration sets were changed every 7 days. The site of needle insertion was dressed with transparent dressing (Tegaderm; 3M Health Care, St. Paul, Minn) in both groups. The dressing was changed when the needles and intravenous administration sets were replaced or whenever dressings were wet or soiled. The unused ports were flushed with 5 mL of normal saline containing 250 units of heparin (50 units/1 mL normal saline) every 4 weeks.
      The following 4 types of catheter-related infections were defined in our study according to Centers for Disease Control and Prevention guidelines
      • Centers for Disease Control and Prevention, Department of Health and Human Services
      Draft guideline for prevention of intravascular device-related infection.
      :
      • 1.
        Bloodstream infection (BSI) : isolation of the same organism from a blood culture drawn from the portal and from the peripheral vein of a patient with accompanying clinical symptoms of BSI and no other apparent source of infection.
      • 2.
        Pocket infection: induration, erythema, and tenderness of the skin over the site of port placement or purulent exudate in the subcutaneous pocket containing the port.
      • 3.
        Exit-site infection : erythema, tenderness, induration within 2 cm of port surface needle access site, or purulence at the port surface needle access site.
      • 4.
        Tunnel infection : erythema, tenderness, and induration in the tissues overlying the catheter and more than 2 cm from the exit site.
      All catheter-related infections in our study were categorized according to these definitions. However, few infections were not proved by cultures but were a physician's clinical diagnosis. We categorized infections as BSI if patients had clinical signs of BSI and had no other sources of infections and the infectious signs subsided after removing the catheter. In our center, the indication to remove an infectious port is determined by the type, severity, and organisms of infections. Infected ports were removed immediately in the following circumstances: (1) when infections were recognized as pocket infections, tunnel infections, or exit-site infections with a large quantity of pus; (2) when infections were associated with septic emboli or infectious endocarditis; and (3) when infections were identified from blood cultures of port reservoirs as being from the Staphylococcus, Candida, Pseudomonas, Bacillus, and the Corynebacterium jeikeium. In our study, few of the catheters were removed on the basis of only the decision of the primary physicians. All catheters removed were sent to the laboratory for cultures, and semiquantitative methods (rolling plate) were used for those cultures.

      Results

      Figure thumbnail gr1
      In total, 205 ports (35%) remained in place until the patients died, 277 ports (47.3%) were still in use at the time the data were reviewed, and 50 ports (8.5%) were removed electively because treatment was completed during the study period. In addition, 54 ports (9.2%) were removed because of complications. Of these, 29 catheters (53.7%) were removed because of infectious complications, and 25 (46.3%) were removed because of noninfectious complications. The median interval for removing catheters because of complications was 122 days (range, 7-662 days). Catheter occlusions that necessitated removal occurred in 18 of the 586 ports inserted (3%) and was the major cause of catheter removal among the noninfectious complications. However, infectious complications were the major reason for premature removal of catheters and were also the major complications associated with catheters in our study.
      Table 1Microbiologic isolation
      OrganismsTotal No. (%)BSI No. (%)
      NFGNB*9 (.30)6 (.20)
      Pseudomonas aeruginosa4 (.13)3 (.10)
      Acinetobacter baumannii2 (.07)1 (.03)
      Stenotrophomonas maltophilia2 (.07)1 (.03)
      Burkholderia cepacia1 (.03)1 (.03)
      Yeast7 (.23)6 (.20)
      Candida albicans6 (.20)5 (.17)
      Other Candida species1 (.03)1 (.03)
      Skin flora11 (.37)5 (.17)
      CoNS6 (.2)4 (.13)
      Corynebacteria1 (.03)0 (0)
      Staphylococcus aureus3 (.10)0 (0)
      Bacillus species1 (.03)1 (.03)
      Entero bactericeae3 (.10)2 (.07)
      Klebsiella pneumoniae1 (.03)1 (.03)
      Escherichia coli1 (.03)1 (.03)
      Serratia marcescens1 (.03)0 (0)
      NFGNB, Nonglucose fermentative gram-negative bacilli; CoNS, Coagulase-negative Staphylococcus.
      Table 2Comparisons of yeast infection with and without TPN
      Total nWith TPN n (%)Without TPN n (%)
      Candida infection75 (71%)2 (29%)
      Bacterial infection262 (8%)24 (92%)
      P =.005; χ2.
      Table 3Comparisons of patients with and without infection
      VariablesTotal nWith infection n (%)Without infection n (%)P value
      SexMan20716 (7.7%)191 (92.3%).1
      Woman37917 (4.5%)362 (95.5%)
      TumorSolid55730 (5.4%)527 (94.6%).2
      Nonsolid293 (10.3%)26 (89.7%)
      Port typePharmacia23913 (5.4%)226 (94.6%)1.0
      Bard34720 (5.8%)327 (94.2%)
      Age≤4015215 (9.9%)137 (90.1%).009
      >4043418 (4.2%)416 (95.8%)
      χ2.
      Table 4Infection comparison between different frequencies of port access needle change (every 3 days vs every week)
      Total nWith TPN n (%)Without TPN n (%)
      Every 3 days1239 (7.3%)114 (92.7%)
      Every week46324 (5.2%)439 (94.8%)
      P =.3; χ2 test.
      All patients with catheter-related infections in our study responded to catheter removal and (or) antibiotic therapy. Most of the catheters (94%) were removed promptly once catheter-related infections were suspected.

      Discussion

      Infections are the most common and feared complications of long-term indwelling catheters. It was previously reported that implanted subcutaneous venous ports have a lower risk of infections and can be maintained in-site longer than other venous devices.
      • Barrios CH
      • Zuke JE
      • Blaes B
      • Hirsch JD
      • Lyss AP
      Evaluation of an implantable venous access system in a general oncology population.
      • Sinoff CL
      • Koski T
      Port-a-Cath in cancer patients.
      • Wesenberg F
      • Flaatten H
      • Janssen CW
      Central venous catheter with subcutaneous injection port (Port-a-Cath): 8 years clinical follow up with children.
      • Poorter RL
      • Lauw FN
      • Bemelman WA
      • Bakker PJM
      • Taat CW
      • Veenhof CHN
      Complications of an implantable venous access device (Port-a-Cath) during intermittent continuous infusion of chemotherapy.
      • Kock HJ
      • Pietsch M
      • Krause U
      • Wilke H
      • Eigler FW
      Implantable vascular access systems: experience in 1500 patients with totally implanted central venous port systems.
      The infection rate of indwelling venous catheters has been reported to range between 2.4% to 16%.
      • Lambert ME
      • Chadwick GA
      • McMahon A
      • Scarffe JH
      Experience with the Port-a-Cath.
      • May GS
      • Davis C
      Percutaneous catheters and totally implantable access systems: a review of reported infection rates.
      • Carde P
      • Cosset-Delaigue MF
      • Laplanche A
      • Chareau I
      Classical external indwelling central venous catheter versus totally implanted venous access systems for chemotherapy administration: a randomized trial in 100 patients with solid tumors.
      • Barrios CH
      • Zuke JE
      • Blaes B
      • Hirsch JD
      • Lyss AP
      Evaluation of an implantable venous access system in a general oncology population.
      • Poorter RL
      • Lauw FN
      • Bemelman WA
      • Bakker PJM
      • Taat CW
      • Veenhof CHN
      Complications of an implantable venous access device (Port-a-Cath) during intermittent continuous infusion of chemotherapy.
      • Kock HJ
      • Pietsch M
      • Krause U
      • Wilke H
      • Eigler FW
      Implantable vascular access systems: experience in 1500 patients with totally implanted central venous port systems.
      • Ballarini C
      • Intra M
      • Pisani Ceretti A
      • Cordovana A
      • Pagani M
      • Farina G
      • et al.
      Complications of subcutaneous infusion port in the general oncology population.
      • Torramade JR
      • Cienfuegos JA
      • Hernandez JL
      • Pardo F
      • Benito C
      • Gonzalez J
      The complications of central venous access systems: a study of 218 patients.
      It also was reported that the average infection rate in cancer patients with long-term central venous catheters is 1 to 2 per 1000 device-days.
      • Raad I
      • Hanna H
      Nosocomial infections related to use of intravascular devices inserted for long-term vascular access.
      The overall infection rate observed in our hospital was similar to that reported by other investigators (5.6% vs 2.4%-16%). However, among cancer patients, the infection rate is lower in our institution (0.12 vs 1-2 per 1000 device-days). The 4 major risk factors associated with catheter-related infections were identified as host factors, catheter type, duration of use, and catheter maintenance and management.
      • Raad I
      • Hanna H
      Nosocomial infections related to use of intravascular devices inserted for long-term vascular access.
      Although we are located in a hot and humid tropical and semitropical area, the catheter-related infection rate is similar to or even better than that of patients who live in drier geographic locations. We believe that our standards of care and maintenance are chiefly responsible for the low infection rate.
      In our study, the younger patients (< 40 years) were more prone to having catheter-related infections and shorter duration of the device in place. Our results are similar to Memorial Sloan-Kettering Cancer Center's report in 1997.
      • Schwarz RE
      • Groeger JS
      • Coit DG
      Subcutaneously implanted central venous access devices in cancer patients: a prospective analysis.
      Since this study was limited to retrospective investigation, the cause of higher infection rate in these younger patients is unclear. The gender of the patients and pathologic findings of the tumor did not relate to the incidence of infection. However, it has been reported that male patients and patients with nonsolid tumors are more likely to have port-related infections.
      • Schwarz RE
      • Groeger JS
      • Coit DG
      Subcutaneously implanted central venous access devices in cancer patients: a prospective analysis.
      Our study has shown that the infection rate among patients with closed-end “Groshong” catheters (MRI port; Bard Access System) and those with open-ended catheters (Port-a-Cath; Pharmacia Implantable Access System) is similar.
      Thus far, there is no safety standard or consensus in practice indicating how long the access needles can be left in-site. Hempsey et al
      • Hempsey SJ
      • Young JE
      • Alcock SR
      • Stack BH
      Needle change preferences and rate of infection in cystic fibrosis adult with a Port-a-Cath device in situ [abstract].
      compared the rate of infection between 2 groups of patients whose access needles were changed with different frequency (1 vs 2 weeks). Although the result of their study was inconclusive, the authors reported that leaving needles in situ for 2 weeks was just as safe as leaving them there for only 1 week. There is also no CDC recommendation for the frequency of dressings change on central catheter sites.
      • Centers for Disease Control and Prevention, Department of Health and Human Services
      Draft guideline for prevention of intravascular device-related infection.
      Our study suggested that when ports are in use, less frequent changes of access needles and dressings (every 7 days vs every 3 days) result in lower incidence of infection (5.2% vs 7.3%, P =.3). It is reasonable to suggest that in cancer patients with implantable ports, it is probably acceptable and safe to change access needles and dressings every 7 days.
      In our study, most port infections occurred after 1 month of implantation. Furthermore, 67% of the infectious organisms isolated were identified as skin flora and nonglucose fermentative gram-negative bacilli. These figures imply that rigorous care of the site of port insertion is the most important factor in preventing catheter-related infections. Establishing a centralized standard of care and maintenance has been shown to reduce catheter-related infection rates significantly.
      • Maki DG
      Infections causes by intravascular devices used for infusion therapy: pathogenesis, prevention and management.
      Although all the care at our institution was not centralized, it was standardized. Maintenance of sterility and patency of the ports in our cancer patients was performed by well-trained nurses in accordance with standard protocols. We believe that diligent nursing care contributed to the low catheter-related infection rate among our cancer patients.
      Staphylococcus, the predominant species found on human skin, are the most common organisms to cause catheter-related infections.
      • Raad I
      • Hanna H
      Nosocomial infections related to use of intravascular devices inserted for long-term vascular access.
      • Maki DG
      Infections causes by intravascular devices used for infusion therapy: pathogenesis, prevention and management.
      Infection caused by the Candida species is more commonly isolated from the immunocompromised host.
      • Wheat LJ
      Fungal infections in the immunocompromised host.
      The Staphylococcus and Candida species bind well to host protein and adhere better to silicone catheters.
      • Raad I
      • Hanna H
      Nosocomial infections related to use of intravascular devices inserted for long-term vascular access.
      In our study, these pathogens also were commonly isolated from the intravenous devices of patients who developed infections. Five of 7 catheters (71%) used for TPN caused infection from the Candida species. However, only 2 of 26 catheters (8%) not used for TPN were associated with Candida infections (P =.005). It should be noted that in patients who developed Candida infections, the median number of days to infection was 44. This interval, which is significantly shorter than that of infections caused by other organisms (44 days vs 126 days), indicates that ports used for TPN are prone to developing fungal infections. Several similar observations of a high incidence of fungal infections among patients receiving TPN indicate that the TPN solution may play a role in fungal infection.
      • Borzotta AP
      • Beardsley K
      Candida infections in critically ill trauma patients: a retrospective case-control study.
      • Chiu NC
      • Chung YF
      • Huang FY
      Pediatric nosocomial fungal infections.
      • Dean DA
      • Burchard KW
      Fungal infection in surgical patients.
      • Flynn PM
      • Marina NM
      • Rivera GK
      • Hughes WT
      Candida tropicalis infections in children with leukemia.
      Certain types of catheters may further increase the incidence of fungal infection when they are used for TPN. Clinicians, therefore, carefully need to select the appropriate catheter for TPN. The results of our study suggest that the intravenous line for TPN should be used with special caution and imply that the port may not be a good choice for delivering TPN in cancer patients.

      Conclusions

      Our observations are similar to those reported by the other investigators: infection is the most common complication in the use of venous port systems among cancer patients. Some catheter-related infections are difficult to prevent due to the general condition of the patient, some types of treatments, and the nature of invasive procedures. However, the infection rate can be significantly lowered by appropriate preventive strategies and by good patient care performed by a well-trained nursing staff. For debilitated and immunocompromised cancer patients, diligent aseptic care is even more important in reducing catheter-related infections. According to our data, it is safe and cost-effective to change exit-site needles and transparent dressings every 7 days. Because most of the infectious organisms are commonly colonized on the skin and in the fluids, it is most important to sterilize and maintain cleanliness of the exit-site area. Finally, our study clearly demonstrates that ports used for the administration of TPN results in the patient having a significantly greater chance of developing infection from the Candida species. The advantages of using ports for chemotherapy in cancer patients have been well documented; however, further investigation is needed to compare the relative advantages of using ports versus other devices for the administration of TPN in cancer patients.

      Acknowledgements

      We are grateful to Cosi Long for her help and support in preparing this manuscript.

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