Aspects of infections in children with cancer

Antibiotic and other lock treatments for tunnelled central venous catheter-related infections in children with cancer

BACKGROUND

The risk of developing a tunnelled central venous catheter (CVC)-related infection ranges between 0.1 and 2.3 per 1000 catheter days for children with cancer. These infections are difficult to treat with systemic antibiotics (salvage rate 24% - 66%) due to biofilm formation in the CVC. Lock treatments can achieve 100 - 1000 times higher concentrations locally without exposure to high systemic concentrations.

OBJECTIVES

Our objective was to investigate the efficacy of antibiotic and other lock treatments in the treatment of CVC-related infections in children with cancer compared to a control intervention. We also assessed adverse events of lock treatments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, issue 3, 2011), MEDLINE/PubMed (1945 to August 2011) and EMBASE/Ovid (1980 to August 2011). In addition we searched reference lists from relevant articles and the conference proceedings of the International Society for Paediatric Oncology (SIOP) (from 2006 to 2010), American Society of Clinical Oncology (ASCO) (from 2006 to 2010), the Multinational Association of Supportive Care in Cancer (MASCC) (from 2006 to 2011), the American Society of Hematology (ASH) (from 2006 to 2010) and the International Society of Thrombosis and Haematology (ISTH) (from 2006 to 2011). We scanned the ISRCTN Register and the National Institute of Health Register for ongoing trials (www.controlled-trials.com) (August 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing an antibiotic lock or other lock treatment (with or without concomitant systemic antibiotics) with a control intervention (other lock treatment with or without concomitant systemic antibiotics or systemic antibiotics alone) for the treatment of CVC-related infections in children with cancer. For the description of adverse events, cohort studies were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, extracted data and performed 'Risk of bias' assessments of included studies. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Two RCTs evaluated urokinase lock treatment with concomitant systemic antibiotics (n = 56) versus systemic antibiotics alone (n = 48), and one CCT evaluated ethanol lock treatment with concomitant systemic antibiotics (n = 15) versus systemic antibiotics alone (n = 13). No RCTs or CCTs evaluating antibiotic lock treatments were identified. All studies had methodological limitations and clinical heterogeneity between studies was present. We found no evidence of significant difference between ethanol or urokinase lock treatments with concomitant systemic antibiotics and systemic antibiotics alone regarding the number of participants cured, the number of recurrent CVC-related infections, the number of days until the first negative blood culture, the number of CVCs prematurely removed, ICU admission and sepsis. Not all studies were included in all analyses. No adverse events occurred in the five publications of cohort studies (one cohort was included in two publications) assessing this outcome; CVC malfunctioning occurred in three out of five publications of cohort studies assessing this outcome.

AUTHORS' CONCLUSIONS

No significant effect of urokinase or ethanol lock in addition to systemic antibiotics was found. However, this could be due to low power or a too-short follow-up. The cohort studies identified no adverse events; some cohort studies reported CVC malfunctioning. No RCTs or CCTs were published on antibiotic lock treatment alone. More well-designed RCTs are needed to further explore the effect of antibiotic or other lock treatments in the treatment of CVC-related infections in children with cancer.

Trends in infections in children with malignant disease in 2000: comparison of data of 1980/81

Children with cancer have an overall chance of survival of 70-80%. Despite significant advances in supportive care during the last years, infections remain a major cause of therapy-associated morbidity and death. Between January and December 2000, oncology patients (ONC) treated on a pediatric oncology ward after chemotherapy (n = 109), loco-regional thermochemotherapy (n = 13), or hematopoietic stem cell (HSCT) transplantation (n = 35) suffered a total of 249 febrile infectious complications (HSCT 40/ONC 209). These episodes were analyzed retrospectively and compared with 125 ONC patients with 133 febrile infections in 1980/81. The relative incidence of fever of unknown origin (FUO) decreased from 1980/81 to 2000 (p <.001). The frequency of bloodstream infections (BSI) in febrile episodes was comparable in both periods with 37% (50/135) in 1980 and 29% (72/249) in 2000. In both periods, gram-positive bacteria were the most frequent organisms, whereas gram-negative organisms were detected in approximately 20% of BSI. In 1980/81 microbiologically (MDI) or clinically documented infections (CDI) were not detected, whereas in 2000 27% of all infectious were MDI/CDI. During the last 20 years, improved diagnostic tools have resulted in an increased detection rate of infectious agents causing febrile episodes in pediatric cancer patients. The comparison of the two observation periods did not reveal a change in the microbiologic spectrum. Despite the fact that in 2000 more patients were treated with intensified chemotherapy because of relapse, infection-related mortality was unchanged compared to 1980/81. This observation may indicate a sufficient preemptive antibacterial therapy followed by better diagnostic tools and goal-oriented treatment.

Limitations of presently available glycopeptides in the treatment of Gram-positive infection

The glycopeptide antibacterial drugs vancomycin and teicoplanin are widely used in hospitals for therapy of severe or multiresistant Gram-positive infections, notably staphylococcal, enterococcal and rarely pneumococcal. Vancomycin has also been used in the management of Clostridium difficile enteropathy. The incidence and potential for resistance differ between agents. The in vitro activity, pharmacokinetics and clinical use of glycopeptide, as well as epidemiology of glycopeptide resistance are discussed. There are limited comparative studies indicating the need for further investigation. Therapeutic drug monitoring has been widely used for vancomycin and less commonly for teicoplanin, but remains controversial. Advances in our understanding of their pharmacodynamics and clinical studies are helping clarify the situation. This paper reviews the current literature and highlights limitations of glycopeptides in treating Gram-positive infection.

Success rates and cost-effectiveness of antibiotic combinations for initial treatment of central-venous-line infections during total parenteral nutrition

BACKGROUND

Central-venous-line infections can be successfully treated with appropriate antibiotics, thus avoiding the need for catheter removal. Based on our experience, vancomycin, gentamicin, piperacillin, ceftazidime, and amphotericin, alone or in combination, are usually administered, pending sensitivity results. This empirical list, however, has never been verified against actual sensitivity results nor has it been tested for cost or efficacy.

METHODS

Medical records of inpatients on hyperalimentation over 1 year were reviewed. Success rate, therapy duration, and drug acquisition cost and charge were assessed for central-venous-line infections. Antibiotics then were paired and evaluated in terms of charge and efficacy against all microorganisms as determined by sensitivity results.

RESULTS

In 500 inpatients receiving hyperalimentation for 9,698 patient-days, 8.4 central-venous-line infections/1,000 patient-days occurred. Staphylococcus non-aureus, Candida species, Enterococcus faecium, and Staphylococcus aureus predominantly were isolated. Of the infections, 51 (67%) were sensitive to one or more of the initial antibiotics. A 2-week course of antibiotics successfully treated 50 (66%) catheter infections without line removal. Appropriate initial therapy on average reduced treatment duration by 8 to 10 days and drug charges by $400 to $700.

CONCLUSIONS

Amikacin-vancomycin appears to be the most cost-effective selection for presumed central-venous-line infections, pending sensitivity results, followed by valid alternatives. Lower failure rates are well worth the extra cost in pharmaceutical charges.

Once daily ceftriaxone plus amikacin vs. three times daily ceftazidime plus amikacin for treatment of febrile neutropenic children with cancer. Writing Committee for the International Collaboration on Antimicrobial Treatment of Febrile Neutropenia in Children

BACKGROUND

The combination of ceftazidime plus aminoglycoside is widely used for the treatment of febrile neutropenic patients but requires multiple daily administration. Because the frequency of Pseudomonas aeruginosa is low in many centers, there is a rationale to test other antibiotic regimens that provide appropriate antibacterial coverage with the advantage of reduced dosing frequency, such as once daily ceftriaxone plus amikacin.

METHODS

Febrile neutropenic children with leukemia, lymphoma or solid tumors after chemotherapy were included in an open, prospective, randomized, multinational study comparing once daily ceftriaxone plus amikacin vs. 8-hourly ceftazidime and amikacin. The response to antimicrobial therapy was defined as complete response, improvement or failure. Assessment of adverse events was supplemented by specific definitions of nephrotoxicity, ototoxicity, hepatotoxicity and hypokalemia. Costs were estimated from published values of acquisition costs, delivery costs and hospitalization costs.

RESULTS

Efficacy was evaluable in 364 of 468 episodes in 265 children. Response rates in ceftriaxone and amikacin vs. ceftazidime and amikacin-treated episodes were 119 of 181 (66%) vs. 121 of 183 (66%), 7 of 181 (4%) vs. 9 of 183 (5%) and 55 of 181 (30%) vs. 53 of 181 (29%) for complete response, improvement and failure, respectively. Safety profiles were similar with both treatment regimens. The acquisition and administration costs were lower for the ceftriaxone and amikacin regimen.

CONCLUSIONS

A once daily regimen of ceftriaxone and amikacin is as safe and clinically effective as that of three times daily ceftazidime and amikacin for the treatment of febrile neutropenic children with cancer and is more cost-effective. The once daily regimen of ceftriaxone and amikacin is suitable for outpatient treatment.

Changing causes of septicaemia in paediatric oncology patients: effect of imipenem use

One hundred and fifty-four episodes of septicaemia occurred in 78 patients on a Paediatric Oncology Unit over 2 years. Septicaemias with Gram-positive bacteria were more common than with Gram-negative organisms, coagulase-negative staphylococci (CNS) being the commonest pathogens. The mortality rate in patients with septicaemia was 1.9%. Azlocillin and gentamicin comprised the first-line of empirical antibiotic therapy for suspected infection for the first 10 months of the study; imipenem with cilastatin, as monotherapy, was used subsequently. More isolates of enterococci, and fewer isolates of Enterobacter, were seen after the introduction of imipenem. The use of imipenem was associated with an increased frequency of resistance to flucloxacillin in CNS. Such strains have been shown to contain sub-populations of cells that are resistant to imipenem. A clinical response was achieved in 82.9% of septicaemic episodes treated with imipenem, compared with 62.7% for azlocillin and gentamicin. However, imipenem as monotherapy may not be appropriate in central venous catheter related infections, owing to the frequent occurrence of imipenem-resistant organisms, CNS and Pseudomonas spp., in this situation.

Infections in the compromised child

Children receiving chemotherapy for malignant diseases show different patterns of infection depending on their underlying disease and its therapy. Granulocytopenia carries the risk of bacterial infection, and also, if prolonged, of fungal infection. Impairment of cell-mediated immunity predisposes to infections with Pneumocystis carinii and is thought to be responsible for severe primary infections with varicella and measles, as well as the severe cytomegalovirus infections seen after allogeneic bone marrow transplantation. Absence or impairment of splenic function predisposes to overwhelming septicaemia with encapsulated organisms, while defects in the normal mechanical barriers to infection provide routes for bacterial and fungal invasion. Despite the lack of physical signs of a normal inflammatory response, clinical evaluation may be critical to the localization of infection in the immunocompromised child. Blood culture and biopsy remain pivotal investigations in the achievement of a microbiological diagnosis. Empirical treatment with a combination of antibiotics has been shown in comparative studies to be effective in initial management of the febrile neutropenic patient: continuing studies are evaluating the role of monotherapy and of different antibiotic combinations, particularly in the light of changing patterns of bacterial infections. Empirical antifungal therapy has been shown to be necessary for persistent or recurrent fever, particularly as persistent fungal infection may compromise the outcome of continuing cytotoxic therapy. Continuing uncertainties over many aspects of management of the infected immunocompromised child provide scope for clinical trials in parallel with trials evaluating new anticancer regimens. The use of new diagnostic methods, the role of prophylaxis, the most appropriate empirical regimen, the evaluation of new antimicrobial agents, all require careful evaluation for efficacy and safety. Perhaps the greatest dilemma of all is how far results from trials in adults can be extrapolated to paediatric practice.