The pathogenesis of catheter-related bloodstream infection with noncuffed short-term central venous catheters

OBJECTIVE: Short-term, noncuffed, percutaneously inserted central venous catheters (CVCs) are widely used and cause more than 250,000 bloodstream infections (BSIs) in hospitals each year in the United States. We report a prospective study undertaken to determine the pathogenesis of CVC-related BSI. DESIGN AND SETTING: Prospective cohort study in a university hospital 24-bed medical-surgical intensive care unit. PATIENTS AND PARTICIPANTS: Patients participating in two randomized trials during 1998-2000-one studying the efficacy of a 1% chlorhexidine-75% alcohol solution for cutaneous antisepsis and the other a novel chlorhexidine-impregnated sponge dressing-formed the study population; CVC-related BSIs were considered to be extraluminally acquired if concordance was identified solely between isolates from catheter segments, skin, and blood cultures and intraluminally acquired if concordance was demonstrated only between hub or infusate and blood culture isolates, as confirmed by DNA subtyping of isolates from blood and catheter sites or infusate. RESULTS: Of 1,263 catheters (6075 CVC days) prospectively studied, 35 (2.7%) caused BSI (5.9 per 1000 CVC days); 27 were caused by coagulase-negative staphylococci. Overall, 45% of infections were extraluminally acquired, 26% were intraluminally derived, and the mechanism of infection was indeterminate in 29%. In the pooled control groups of the two trials, 25 CVC-related BSIs occurred (7.0 per 1000 CVC days), of which 60% of infections were extraluminally acquired, 12% were intraluminally derived and 28% were indeterminate. In contrast, CVC-related BSIs in the treatment groups were most often intraluminally derived (60%, p=0.006). CONCLUSIONS: Most catheter-related BSIs with short-term percutaneously inserted, noncuffed CVCs were extraluminally acquired and derived from the cutaneous microflora. Strategies achieving successful suppression of cutaneous colonization can substantially reduce the risk of catheter-related BSI with short-term CVCs.     

Inflammation at the insertion site is not predictive of catheter-related bloodstream infection with short-term,noncuffed central venous catheters

BACKGROUND: Noncuffed, percutaneously inserted central venous catheters (CVCs) are widely used and cause at least 250,000 bloodstream infections (BSIs) in U.S. hospitals each year. We report a prospective study to determine whether inflammation at the insertion site is predictive of CVC-related BSI. METHODS: Percutaneously inserted, noncuffed CVCs inserted into the subclavian, internal jugular, or femoral vein in two randomized trials during 1998-2000 were prospectively studied; most patients were in an intensive care unit. The condition of the insertion site was evaluated daily by research nurses, quantifying pain (0, 1), erythema (0-2), swelling (0, 1), and purulence (0, 1); the lowest possible overall inflammation score was 0 and the highest was 5. CVC-related BSI was confirmed in each case by demonstrating concordance between isolates from the catheter segment and from blood cultures by restriction-fragment DNA subtyping. RESULTS: Among 1,263 CVCs prospectively studied, 333 (26.3%) were colonized at removal; of these, 35 catheters (2.7%) caused BSIs (5.9 per 1000 CVC days). BSIs were caused by coagulase-negative staphylococci (n = 27), enterococci (n = 4), enteric Gram-negative bacilli (n = 3), or (n = 1). Most insertion sites showed little or no inflammation at the time of removal. There were no significant differences among mean scores for each inflammatory variable examined or overall score among colonized CVCs (0.1 +/- 0.1), catheters causing CVC-related BSI (0.2 +/- 0.4), and noncolonized CVCs (0.1 +/- 0.1). The sensitivity of local inflammation for diagnosis of CVC-related BSI was dismal (0-3%). CONCLUSION: Local inflammation is uncommon with infected CVCs, probably because most catheter-associated infections are currently caused by coagulase-negative staphylococci, a pathogen that incites little local or systemic inflammation. Whereas overt inflammation of the insertion site should raise suspicion of CVC-related BSI caused by or Gram-negative bacilli, especially if the patient has fever or other signs of sepsis, in general, site appearance cannot be relied on to identify catheter colonization or CVC-related BSI.     

One percent chlorhexidine-alcohol for preventing central venous catheter-related infection during intensive chemotherapy for patients with haematologic malignancies

A central venous catheter (CVC) is a catheter placed into a large vein, and is used for chemotherapy administration. However, there is little confirmatory data on which antiseptic—such as chlorhexidine or povidone-iodine (PI) —is more protective against CVC-related infectious complications in patients receiving intensive chemotherapy. We aimed to compare the effectiveness of 1% chlorhexidine gluconate in 70% alcohol (CH) vs. PI for skin disinfection before CVC insertion in patients receiving intensive chemotherapy. Methods We used either CH or 10% PI as skin antiseptics before CVC insertion, and assessed which agent was more protective against CVC-related infection. The participants were 112 patients with haematologic malignancies who underwent chemotherapy; a total of 292 CVCs were inserted over this period. Blood cultures were obtained when febrile neutropenia occurred. The CVC was removed and the catheter-tip qualitatively cultured when catheter-related infection was suspected. The cumulative incidence of febrile neutropenia, microbial growth from blood or catheter-tip culture, and catheter-related blood stream infection (CRBSI) was evaluated retrospectively. A univariate Cox proportional hazards model showed that CH significantly alleviated infectious complications. Notably, no case of CRBSI occurred in the CH group. Multivariate analysis, adjusted for prolonged neutropenia (>15 days) and older age (>52 years), also showed significant reduction in the cumulative incidence of microbial growth from catheter-tips in the CH group (hazard ratio = 0.146, 95% confidence interval: 0.023–0.502, p = 0.0008). Disinfection using CH, compared with PI, can potentially decrease catheter-related infection without causing adverse skin reactions in patients with haematologic malignancies.     

Mechanical and infective central venous catheter-related complications: a prospective non-randomized study using Hickman and Groshong catheters in children with hematological malignancies

 The aim of this study was to compare the Hickman and Groshong central venous catheters (CVCs) for incidence and severity of catheter-related complications in children. Seventy-three patients with hematological malignancies were observed, 42 with Groshong CVCs and 31 with Hickman CVCs. The number of infective episodes per 100 CVC-days was not significantly different (0.25 in the Hickman group versus 0.13 in the Groshong group;P=0.24). The most frequent type of CVC-related infection in both groups was microbiologically documented sepsis; in most cases Gram-positive bacteria were isolated. Neutropenia (P<0.001 for both CVCs) and hospital CVC management (P=0.0047 for the Hickman group, P<0.001 for the Groshong group) emerged as the major risk factors for the outbreak of infections. The rate of mechanical complication episodes per 100 CVC-days was similar in both groups (1.01 in the Hickman group versus 1.1 in the Groshong group;P=0.58). Some complications (fissures, ruptures, total lumen obstruction by clots) occurred only in the Groshong group. Our study did not demonstrate any statistically significant difference in the incidence of mechanical and infective CVC-related complications between these two types of catheter.     

Central venous catheter infection in adults in acute hospital settings

As well as the human cost, central venous catheter (CVC)-related bloodstream infections significantly inflate hospital costs, mainly through increased length of stay in hospital, particularly in intensive care. This literature review appraises recent research on measures used to minimize CVC-related infection and compares it with current best practice. Randomized controlled trials and systematic reviews published on the subject between 2000 and 2005 were reviewed, concentrating on non-tunnelled, short-term CVCs in the acute hospital setting. The new evidence mainly backs up current best practice. However, skin disinfection could be improved by using alcoholic chlorhexidine followed by aqueous povidone-iodine before CVC insertion. Also, alcoholic chlorhexidine is the preferred solution for cleaning the hubs/connectors before accessing the CVC. Good hand hygiene and quality control and education programmes are vital to improve patient care. More research is needed to clarify the effectiveness of certain interventions and technologies, such as antimicrobial CVCs.     

Infective and thrombotic complications of central venous catheters in patients with hematological malignancy: prospective evaluation of nontunneled devices

Goals  Central venous catheter (CVC)-related bloodstream infection (CR-BSI) is a significant complication in hematology patients. A range of CVC devices may be used, and risks for the development of complications are not uniform. The objectives of this study were to determine the natural history and rate of CVC-related complications and risk factors for CR-BSI and to compare device-specific complications in a hematology population. Patients and methods  An observational cohort of patients with hematologic malignancy was prospectively studied following CVC insertion. Participants were reviewed until a CVC-related complication necessitated device removal, completion of therapy, death, or defined end-of-study date. The National Nosocomial Infection Surveillance definition for CR-BSI was used. Overall and device-specific rates of infective and noninfective complications were calculated and potential risk factors were captured. Main results  One hundred six CVCs (75 peripherally inserted central venous catheters [PICCs], 31 nontunneled CVCs) were evaluated in 66 patients, over 2,399 CVC days. Thrombosis occurred in 16 cases (15.1%), exit-site infection in two (1.9%), and CR-BSI in 18 (7.5 per 1,000 CVC days). No significant differences were found when complication rates in PICC and nontunneled devices were compared. An underlying diagnosis of acute myeloid leukemia was negatively associated with CR-BSI (odds ratio (OR) 0.14, p = 0.046), and a previous diagnosis of fungal infection was associated with infection (OR 22.82, p = 0.031). Conclusions  CR-BSI rates in our hematology population are comparable to prior reports. A low rate of exit-site infection and high proportion of thrombotic complications were observed. No significant differences in thrombotic or infective complications were evident when PICC and nontunneled devices were compared. PICC devices are a practical and safe option for management of hematology patients.     

Watchful waiting versus immediate catheter removal in ICU patients with suspected catheter-related infection: a randomized trial

Objective To find a subset of patients with suspected central venous catheter (CVC)-related infection (CRI) in whom CVC removal is not needed.Design Randomized controlled trial.Setting Thirty-three-bed ICU.Patients and participants One hundred and forty four patients with suspected CRI in which a change of CVCs was planned were evaluated for inclusion.Interventions Hemodynamically stable patients without proven bacteremia, no insertion site infection, and no intravascular foreign body were randomized to a standard-of-care group (SOC, all CVCs were changed as planned) or a watchful waiting group (WW, CVCs changed when bacteremia was subsequently confirmed or hemodynamic instability occurred).Measurement and results Study groups were compared for incidence of CVC-related bloodstream infection (CR-BSI), resolution of fever, C-reactive protein, SOFA score, duration of ICU stay, and mortality. Of 144 patients with suspected CRI, 80 patients met exclusion criteria. Sixty-four were randomized. Forty-seven of 80 excluded patients were shown to be bacteremic, 20 (25%) of whom had a CR-BSI. Five of 64 (8%) included patients had a CR-BSI during their subsequent ICU stay (two in SOC and three in WW group). All 38 CVCs were changed in the SOC group versus 16 of 42 in the WW group (62% reduction, P<0.01). Resolution of fever, C-reactive protein, SOFA score, duration of ICU stay, and ICU mortality did not differ between SOC and WW group (P>0.1 for all).Conclusions The use of a simple clinical algorithm permits a substantial decrease in the number of unnecessarily removed CVCs without increased morbidity.An editorial regarding this article can be found in the same issue ()     

Central venous catheter-related bloodstream infections: an analysis of incidence and risk factors in a cohort of 400 patients

Objective: To determine the incidence of central catheter-related bloodstream infection (CR-BSI) and to compare patient and catheter characteristics of those with and without CR-BSI from a clinically suspected subgroup. Secondly, to assess the efficacy of the acridine orange leucocyte cytospin test (AOLC) as a rapid in situ method of detecting central venous catheter (CVC) infection. Design: One-year prospective audit. Setting: Intensive care unit/high dependency unit (ICU/HDU) and general wards of a tertiary referral hospital. Patients and participants: 400 patients with non-tunnelled CVCs. Interventions: Daily surveillance, blood culture from peripheral venepuncture, blood sample from the CVC for assessment of the AOLC test and removal of suspected CVCs were carried out on patients clinically suspected of having CR-BSI. Measurements and results: CR-BSI was diagnosed using well defined criteria. Infection rate was calculated by dividing the number of definitive catheter associated infections by the total number of appropriate catheter in situ days. The AOLC test was performed on all those with suspected CR-BSI. A total of 499 CVCs in 400 patients were assessed, representing 3014 catheter in situ days. Over 80 % of patients were from our ICU/HDU, representing 404 CVCs and 1901 catheter in situ days. A total of 49/499 (9.8 %) CVCs in the same number of patients were suspected of being infected subsequently 12/499 (2.4 %) CVCs [95 % confidence interval (CI) 1.25 to 4.16] in 12 separate patients were demonstrated to be the direct cause of the patient's BSI. Rates of CR-BSI per 1000 catheter days were 3.98 (95 % CI 2.06 to 6.96) for the whole cohort and 4.20 (95 % CI 1.81 to 8.29) for the ICU/HDU subgroup. In the group suspected of having CR-BSI, CVCs were removed unnecessarily in 55 %, and no patient or catheter variables measured were predictive of the development of CR-BSI. The AOLC test was negative in all 12 catheters subsequently shown to be the definitive cause of BSI. Conclusions: We have defined the incidence of CR-BSI in a cohort of patients from a tertiary referral hospital, the rates comparing favourably with those reported for similar populations. We were unable to demonstrate significant differences in any patient or catheter variables between those with and without CR-BSI. The AOLC test used alone was unhelpful as a method to diagnose in situ CVC infection in this patient population. Received: 26 February 1998 Accepted: 30 June 1998     

急性白血病化疗后医院感染危险因素分析

目的探讨急性白血病患者化疗后医院感染的临床特点、病原菌分布和危险因素。方法回顾性调查分析2009—2011年在福建省立医院住院化疗的急性白血病患者的医院感染情况。结果 40例急性白血病患者累计接受188个疗程化疗,医院感染率为32.9%。常见感染病种依次为肺炎30.6%、急性咽炎24.2%、血流感染11.3%、口腔感染11.3%和肠道感染8.1%。革兰阴性菌和革兰阳性菌为常见的病原菌。急性白血病患者化疗后医院感染发生率与年龄、糖尿病、中性粒细胞缺乏时间和白血病疾病状态显著相关。结论年龄、糖尿病、中性粒细胞缺乏时间和疾病病情是急性白血病患者化疗后医院感染的重要危险因素,应针对其采取有效的预防措施和重点监护以降低感染率,从而改善患者预后。     

Oral enoxacin for infection prevention in adults with acute nonlymphocytic leukemia. The Enoxacin Prophylaxis Study Group.

A randomized, double-blind, placebo-controlled trial was conducted in eight hematologic units to determine the efficacy and safety of oral enoxacin for infection prevention in adult patients with acute nonlymphocytic leukemia. One hundred nineteen patients undergoing remission induction or consolidation chemotherapy were enrolled; 62 of them received enoxacin (400 mg orally every 12 h). Patients received antifungal prophylaxis with oral mycostatin (1,000,000 U four times daily) or clotrimazole (1 troche five times daily). Analysis was performed on an intent-to-treat basis. There was no significant difference between groups in race, age, or type and stage of leukemia, but there were more males in the placebo group (P = 0.073 [Fisher's exact test]). Fewer enoxacin patients had gram-negative bacteremia (1 versus 14 [P < 0.001]), gram-negative infection at any site (2 versus 19 [P < 0.001]), or bacterial and/or fungal infection (17 versus 26 [P = 0.056]). There was no significant difference in the number of patients with gram-positive infection at any site (12 versus 16), gram-positive bacteremia (9 versus 10), deep fungal infection (6 versus 2), death (2 versus 3), other antimicrobial therapy required (48 versus 48), therapy with amphotericin B (15 versus 7 [P = 0.105]), any adverse event (45 versus 36), or any study drug-associated adverse events (13 versus 6). Logistic regression confirmed (odds ratios and 95% confidence intervals are given in parentheses) that enoxacin reduced the risk of gram-negative infection (0.07; 0.01 to 0.30), especially gram-negative bacillary bacteremia (0.05; 0.01 to 0.37), without altering the risk of gram-positive bacterial (0.63; 0.26 to 1.5), deep fungal (2.57; 0.47 to 13.9), or Clostridium difficile (1.16; 0.3 to 4.56) infection. The median time to the onset of fever of more than or equal 102.8 F (39.3 degree C) was 32 days for the enoxacin group versus 15 days for patients receiving placebo (P=0.0007 [Wilcoxon test]). In patients with acute nonlymphocytic leukemia, oral enoxacin prevents gram-negative infections, delays the onset of fever, does not alter the incidence of gram-positive or proven deep fungal infections, and is well tolerated.     

Antimicrobial chlorhexidine/silver sulfadiazine-coated central venous catheters versus those uncoated in patients undergoing allogeneic stem cell transplantation

Introduction  Only a minimum is known about clinical effect of antimicrobial-coated central venous catheters (CVC) in stem cell transplantation settings, where CVC-related infections impose major threat to severely immunocompromised patients. Materials and methods  In this prospective, non-sponsored and nonrandomized study, there were 49 uncoated multi-lumen and non-tunneled CVCs and 58 antimicrobial chlorhexidine/silver sulfadiazine-coated CVCs inserted in allogeneic stem cell transplanted patients to facilitate treatment during conditioning and pre-engraftment phase (<30days after transplantation). Results and discussion  No significant differences were found between the two groups with respect to gender, age, intensity of pretransplant chemotherapy conditioning, duration of leucopenia, number of days with inserted CVC, number of CVC occlusive dressing changes performed per patient, and number of non-CVC-related infections. In the antimicrobial coated CVC group, there were observed less median days with fever [2 (0–18) vs. 4 (0–16), p = 0,17], fever incidence (67% vs. 77.5%, p = 0.28), and less days with fever per 1,000 catheter-days (108 vs. 147, p = 0.001), less patients with positive CVC blood cultures (36% vs. 45%, p = 0.05), repeatedly positive CVC blood cultures (8.6% vs. 26%, p = 0,018), less positive CVC blood cultures per 1,000 catheter-days (14 vs. 29, p = 0.005), and less positive CVC tip cultures (17.3% vs. 34.6%, p = 0.065) observed. Conclusion  Lower number of patients with fever, days with fever, and lower number of patients with positive and repeatedly positive CVC blood cultures indicates less intensive antibiotic and antipyretic treatment probably needed in neutropenic allo-transplanted patients with indwelling antimicrobial-coated CVCs. Real impact on antibiotic consumption should be verified in large randomized study.     

A randomized trial of roxithromycin in patients with acute leukemia and bone marrow transplant recipients receiving fluoroquinolone prophylaxis.

Fluoroquinolone prophylaxis in patients with profound neutropenia may be useful for preventing gram-negative bacterial infection, but it is ineffective against gram-positive bacterial infections in the bloodstream, particularly those caused by streptococci and coagulase-negative staphylococci, which appear to have emerged as significant causes of morbidity, decreased treatment efficacy, and the increased costs of empiric antimicrobial therapy. In a prospective, randomized, open trial, we evaluated the efficacy and safety of oral roxithromycin (150 mg twice daily) as additional antibacterial prophylaxis in 131 adult patients with acute leukemia and bone marrow transplant recipients receiving oral ofloxacin. In comparison with patients given ofloxacin alone, fewer patients receiving ofloxacin plus roxithromycin developed bacteremia caused by viridans group streptococci (incidence, 9 versus 0%; P = 0.03), while the incidence of bacteremia caused by other organisms, the incidence of febrile episodes from any cause, the risk of infection-associated complications (including prolonged or secondary fever, pneumonia, septic shock, need for mechanical ventilation, and/or infection-related death), and antimicrobial usage for therapy were comparable between both groups. Adverse events possibly related to the study drugs were slightly more common among the patients receiving the combination treatment (P = 0.05). Although effective for the prevention of streptococcal bacteremia, the addition of roxithromycin to a fluoroquinolone should not be used routinely as a prophylactic regimen in patients with profound neutropenia, but it might be considered and may be useful for cancer patients with a particularly high risk of streptococcal infection and related complications.     

Colonization of central venous catheters

We studied etiologic factors important in colonization of 179 central venous catheters (CVCs) in patients randomized into group 1 (who received daily topical applications of povidone-iodine) or group 2 (who received only dry dressing changes). Colonization rates of CVC tips were similar between group 1 (18/84 or 21%) and group 2 (22/95 or 23%). Peripheral blood cultures grew Candida in eight hyperalimented patients (evenly divided between groups 1 and 2), S epidermidis in four other patients (also evenly divided), and gram-negative bacteria in three patients. Colonization rates for CVCs in place for 0 to seven days was 15.6% (17/109) and 76.7% (23/30) if used from eight to 30 days. Inflammatory signs at CVC sites were often absent when CVCs became colonized or produced bacteremia. Unimportant determinants of CVC colonization included skin securement of CVCs, antibiotic infusions through CVC lines, and masking and gowning of physicians before CVC placement. Daily applications of povidone-iodine did not reduce colonization of CVCs as compared to dry dressing changes.     

Chlorhexidine versus povidone-iodine for central venous catheter site care in children

The number of children receiving central venous catheters (CVCs) for the administration of medications is at an all-time high. Unfortunately, placement of these CVCs is not without risks. Infection of CVC insertion sites is one of the most common, yet often preventable, causes of nosocomial bacteremia in both children and adults worldwide. Throughout the years, multiple practice recommendations have been made regarding the proper site care of CVCs. The most popular antimicrobial solution used for site care has traditionally been povidone-iodine. Chlorhexidine gluconate solution, however, has been shown to be more effective than povidone-iodine in preventing CVC-related infections in adults. There continues to be controversy regarding the efficacy and safety of antimicrobial solutions for pediatric CVC site care. An evidence-based approach was used to determine current recommendations for CVC site care in children.     

Each lumen is a potential source of central venous catheter-related bloodstream infection

OBJECTIVE: To determine the relative rates of microbial colonization of individual lumens in triple-lumen central venous catheters (CVCs) and calculate the chance of detecting catheter-related blood stream infection (CRBSI) if only one lumen is sampled. DESIGN: Prospective evaluation of CVCs from suspected and nonsuspected CRBSI cases. SETTING: University teaching hospital. PATIENTS: Triple-lumen CVCs from 50 cases of suspected CRBSI (a raised peripheral white blood cell count, temperature >37 degrees C, and/or local signs of infection at the catheter skin entry site) were evaluated. For comparison, 50 triple-lumen CVCs routinely removed at the end of use were evaluated. MEASUREMENTS: In both groups, peripheral blood cultures were taken before CVC removal. After CVC removal, each lumen was sampled in vitro using the endoluminal brush, and the tip was then cultured using the Maki roll technique. MAIN RESULTS: CVCs causing CRBSI had significant microbial colonization in one, two, or three lumens in ten (40%), ten (40%), or five (20%) cases, respectively. Overall, random sampling of only one lumen in CVCs causing CRBSI had a 60% chance of detecting significant colonization. CONCLUSIONS: If only one CVC lumen is sampled, a negative result does not reliably rule out infection. Each lumen of multiple-lumen CVCs should be considered as a potential source of CRBSI.     

Acridine orange leukocyte cytospin test for central venous catheter--related bloodstream infection: a pediatric experience

The aim of this study was to evaluate the acridine orange leukocyte cytospin (AOLC) test for the rapid diagnosis of septicemia caused by central venous catheters (CVCs), without removing the catheter, in a pediatric intensive care unit population. Twenty-six patients admitted in the pediatric intensive care unit of Azienda Ospedaliera "Ospedali Riuniti di Bergamo", Italy, were prospectively evaluated for CVC-related infection. Blood for culture was taken from all patients. Quantitative endoluminal cultures of the removed catheter tip by Cleri's technique and semiquantitative superficial cultures of the hub were performed. Gram staining and an AOLC smear were done according to Kite's technique. Four Staphylococcus CVC-related bloodstream infections were identified. CVC colonization was detected in 8 patients. Four had septicemia (Enterococcus faecalis, Escherichia coli, Klebsiella oxytoca, Candida glabrata) without CVC involvement. However, Gram staining and the AOLC test were negative in all cases. We conclude that cytocentrifugation and acridine orange staining of blood withdrawn by Kite's method from an in situ catheter, although simple, quick, and inexpensive, did not aid diagnosis in this pediatric population.     

Vancomycin and ciprofloxacin: systemic antibiotic administration for peritoneal dialysis-associated peritonitis.

OBJECTIVES: Peritonitis due to peritoneal dialysis (PD) is best treated empirically while waiting for the results of the dialysate culture. Thus, antibiotic therapy must cover both gram-positive and gram-negative micro-organisms. First, over a period of 9 years in a multicenter study we evaluated the efficiency of a vancomycin and ciprofloxacin combination given as the first-line treatment protocol for PD peritonitis. Second, we evaluated whether a systemic route of administration of the antibiotics could be an interesting alternative to the usual cumbersome intraperitoneal drug administration. METHODS: Vancomycin 15 mg/kg body weight, intravenous, and oral ciprofloxacin 250 mg two times per day (500 mg twice per day if residual creatinine clearance was above 3 mL/minute) were prescribed at diagnosis of peritonitis. Vancomycin injections were repeated (when blood trough level was expected to be below 12 microg/mL) in cases of gram-positive organisms for a total duration of 3 weeks. Ciprofloxacin was given for a total of 3 weeks in cases of gram-negative and a total of 10 days for susceptible gram-positive infections. RESULTS: A total of 129 episodes of peritonitis occurred; 28 of them were not included in the study because of protocol violation (n = 15) or fungal (n = 7) or fecal (n = 6) peritonitis, leaving 101 peritonitis episodes for analysis. 52 (51.5%) gram-positive and 28 (27.7%) gram-negative organisms were grown; 38 gram-positive organisms were coagulase-negative staphylococci. No organism was identified in 8 peritonitis episodes, whereas 13 peritonitis episodes were caused by more than 1 organism. 35% of the coagulase-negative staphylococci were resistant to first-generation cephalosporin and methicillin, whereas all were susceptible to vancomycin. For gram-negative bacilli, the susceptibility rate was 96% and 95% for ciprofloxacin and ceftazidime respectively. The overall treatment success rate was 77.2% (78 of the 101 peritonitis episodes): 61.4% at first intention and 15.8% after optimization of the antibiotic therapy (second intention).The protocol failed in 22.8% of the peritonitis episodes. Hospitalization was required in 52% of the peritonitis episodes; average hospitalization was 11 (range 1-45) days. CONCLUSION: Systemic vancomycin and ciprofloxacin administration is a simple and efficient first-line protocol antibiotic therapy for PD peritonitis. In our opinion, vancomycin should still be used for gram-positive infections because of its high susceptibility rate compared with first-generation cephalosporins, providing a close monitoring of the local epidemiology. Oral ciprofloxacin provides satisfactory results in gram-negative infections, comparable to those obtained with intraperitoneal ceftazidime or aminoglycosides.     

Are central venous catheter tip cultures reliable after 6-day refrigeration?

Present guidelines recommend culturing only central venous catheter (CVC) tips from patients with suspected catheter-related bloodstream infection (CR-BSI). However, a high proportion of these suspicions are not confirmed. Moreover, CVC tip culture increases laboratory workload, and reports of colonization may be meaningless or misleading for the clinician. Our working hypothesis was that CVC tips should be refrigerated and cultured only in patients with positive blood cultures. We evaluated the effect of 6-day refrigeration of 215 CVC tips. We selected all the catheters with a significant count according to the Maki's roll-plate technique and randomly assigned them to 2 groups. In group A, the catheters were recultured after 24 h of refrigeration, and in group B, the catheters were recultured after 6 days more of refrigeration, so that the refrigeration time evaluated would be of 6 days. The yield of refrigerated CVC tips that grow significant colony counts of primary culture in group B was compared with the yield of refrigerated catheter tips in group A. The difference showed that 6-day refrigeration reduced the number of significant CVCs by 15.2%. Only 61 CVCs were obtained from patients with CR-BSI, and in most of them, blood cultures were already positive before CVC culture, so only 0.91% of the CR-BSI episodes would have been misdiagnosed as culture negative after refrigeration. Refrigeration of CVC tips sent for culture and culturing only those from patients with positive blood cultures reduce the workload in the microbiology laboratory without misdiagnosing CR-BSI.     

Candidemia in acute leukemia patients

 Fungal infections are an important cause of morbidity and mortality in patients with acute leukemia (AL). Candidemia, once rare, is now a common nosocomial infection because of the intensity of chemotherapy, prolonged neutropenia, administration of broad-spectrum antibiotics and use of central venous catheters (CVC). We retrospectively identified patients treated for AL from 6/86 to 6/95 who also had candidemia. We describe 28 patients (incidence 6.3%) with a median age of 39 years, 24 of whom were on remission induction and 4 on postremission chemotherapy. All patients had CVC and empiric antimicrobial therapy, 4 had been given prophylactic antifungal drugs, and 2 had parenteral nutrition. Neutropenia was profound (median leukocyte nadir 200/μl, median duration 19 days). Candida was isolated in blood cultures 10 days (median) after the start of neutropenia. The clinical presentation included fever (100%), respiratory symptoms (71.4%), skin lesions (39.2%) and septic shock (17.8%). Amphotericin B was given to 17 patients and liposomal amphotericin to 5 patients. Infection resolved in 18 patients (64.2%), 10 of whom were in complete remission. Mortality from candidemia was 17.8% (5/28). In conclusion, fungal infections are responsible for death in a significant number of patients. In our series treatment success was related to its rapid onset and to the recovery of neutropenia.