Central Venous Lines in Children With Lesser Risk Acute Lymphoblastic Leukemia: Optimal Type and Timing of Placement

Central venous access ports in children treated for hematopoietic malignancies

During past 10 years 234 central venous access ports (CVAP) were implanted in 225 patients at the Department of Pediatric Hematology and Oncology in Zabrze. Mean exposure time was 745 days and total implantation time reached 173,768 days. Complications were encountered in 17 patients (7.6%). This mainly concerned central venous line infection, which led to removal of 10 CVAP (4.4%). The remaining complications necessitating removal of the CVAP consisted mainly of mechanical problems (catheter fracture, occlusion, and erroneous implantation to artery). In the opinion of the authors, subcutaneously implanted CVAP are a safe and effective option for high-dose chemotherapy deliverance in childhood cancer patients.

Epidemiology and clinical risk factors predisposing to thromboembolism in children with cancer

PURPOSE

The prevalence and risk factors for thromboembolism (TE) in children with cancer are largely unknown. This retrospective cohort study aims to determine the epidemiology of TE and to identify potential risk factors for TE in children with cancer.

METHODS

We used logistic regression to determine the association of age (<10 years vs. > or =10 years), gender, type of cancer, presence or absence of intra-thoracic disease (mediastinal mass or any primary or metastatic pulmonary disease), type of central venous line (CVL) and CVL-dysfunction (difficulty of blood draw, infusion or documented CVL infection) on the risk of developing TE.

RESULTS

Fifty-seven of 726 patients [7.9%; 95% confidence intervals (CI); 6.0,10.0] developed TE; children with brain tumors (n = 201) had significantly lower prevalence of TE (0.5%; P < 0.001). Older patients had increased risk of developing TE compared to younger patients [Odds ratios (OR) 1.8; 95% CI; 1.0,3.2; P = 0.036]. Children with acute lymphoblastic leukemia (ALL) (OR 4.6; 95% CI; 1.8, 12.3; P = 0.002), lymphoma (OR 3.8; 95% CI; 1.3, 11.1; P = 0.016), and sarcoma (OR 4.3; 95% CI; 1.4, 13.3; P = 0.012) had an increased risk of TE. Subgroup analyses showed that patients with CVL-dysfunction and intra-thoracic disease had a higher prevalence of TE compared to those without CVL-dysfunction (22.8% vs. 8.8%; 95% CI; 4.0, 24.3; P = 0.006) and intra-thoracic disease (18.0% vs. 6.1%; 95% CI; 2.4, 21.4; P = 0.02).

CONCLUSIONS

TE is common in children with cancer. Age and type of cancer are independent risk factors for TE in children with non-CNS cancers. CVL-dysfunction and intra-thoracic disease are significantly associated with the diagnosis of TE.

Inherited thrombophilic factors do not increase central venous catheter blockage in children with malignancy

BACKGROUND

Central venous catheter (CVC) blockage is a common complication in pediatric oncology patients. We investigated whether inherited thrombophilic factors may predispose Chinese children with cancer to CVC blockage.

METHOD

Newly diagnosed patients with CVC inserted were recruited during a 30-month period and prospectively followed until CVC removal, end of treatment or death. Protein C (PC), protein S (PS), anti-thrombin III (AT-III), Factor V Leiden (FVL), prothrombin 20210 variant (p20210), and methylenetetrahydrofolate reductase (MTHFR) polymorphism (C677T), were studied with other acquired factors. The primary endpoint was CVC blockage and symptomatic thromboembolic events (TE) were recorded.

RESULT

Thirty-six patients were recruited. CVC blockage was found in 3/36 (8.3%) and the incidence was 0.23 per 1,000 catheter-days. Among the 3 with CVC blockage, 2 were heterozygous for MTHFR polymorphism and 1 was heterozygous for PC deficiency. One with ALL developed superior saggital sinus thrombosis while on asparaginase and he was heterozygous for MTHFR polymorphism. One ALL patient with combined heterozygous MTHFR polymorphism, PC and PS deficiency did not develop any CVC blockage during a median follow-up of 3.8 years. AT-III deficiency, FVL and p20210 were not found in all patients.

CONCLUSION

Compared to previous studies, our cohort had a much lower incidence of CVC blockage. A different pattern of inherited thrombophilic factors was found with heterozygous MTHFR polymorphism being the most common. We concluded that inherited thrombophilic factors alone were not associated with CVC blockage in our pediatric cancer patient population.

Empiric treatment with once-daily cefonicid and gentamicin for febrile non-neutropenic pediatric cancer patients with indwelling central venous catheters

The approach to treating febrile non-neutropenic hematooncologic patients with central venous catheters varies. We recently introduced once-daily administration of cefonicid and gentamicin for such children who were in good clinical condition and without focal signs of infection. Our 2-year experience of 125 episodes in 54 children is hereby reported. Absolute neutrophil counts were 550 to 16,700/mm. Bacteremia occurred in 6.4% episodes: only in patients with Hickman/Broviac catheters and not in those with port-a-caths [8/37 (21.6%) vs. 0/17 patients, P=0.046; 8/86 (9.3%) vs. 0/39 episodes, P=0.056]. The pathogens were coagulase-negative staphylococci (3), Streptococcus pneumoniae (2), Pseudomonas aeruginosa and Klebsiella pneumoniae (1), methicillin-sensitive Staphylococcus aureus (1), and Streptococcus milleri (1). All patients remained in stable clinical condition and all, except for 2 who became neutropenic and 1 with S. aureus bacteremia who developed cellulitis, defervesced while on the empiric therapy. Three episodes could not be managed as outpatients. No adverse effects were observed. We conclude that our approach is efficacious and safe and, furthermore, that empiric antibiotic therapy may not be indicated for selected patients with port-a-caths. Future study of children with Hickman/Broviac catheters will evaluate the use of cefonicid alone.

Risk determinants for catheter-associated blood stream infections in children and young adults with cancer

BACKGROUND

Catheter-associated blood stream infections (CABSI) are frequent complications encountered with cancer treatment. In order to understand which factors might predispose to CABSIs in children and young adults, we evaluated risk for infection in association with tumor type, catheter type, and setting of occurrence.

METHODS

All pediatric oncology patients having a central venous catheter (CVC) with a tunneled external (TE) or totally implantable design (TID) were prospectively followed for the occurrence of a CABSI for 12 months. CABSIs were defined in accordance with the guidelines published by the Centers for Disease Control, and were quantified as the number of occurrences per 1,000 device days. Rates of CABSIs were stratified by tumor histology, type of catheter design, and setting of occurrence. Statistical comparisons were made using the Mantel-Haenzel statistic and the Cox proportional hazard model.

RESULTS

A total of 58 CABSIs were identified in 139 patients over a period of 35,935 CVC days. The overall CABSI rate was 1.6 infections per 1,000 CVC days (95% CI 1.2, 2.1). Stratified analysis demonstrated increased risk for CABSIs in hospitalized patients having TEs, and while patients with solid tumors were also at higher risk; this association was not supported by the Cox proportional hazard model.

CONCLUSION

While our baseline CABSI rate was comparatively lower than for other institutions, subset analyses identified that hospitalized cancer patients having TEs are at the highest risk for developing CABSIs. Our findings may help to guide improved methods of anticipating and controlling infections in immunocompromised patients.

Venous thrombosis in children with solid tumors

BACKGROUND

The prevalence of venous thrombosis (VT) in children with solid tumor and the role of different risk factors are not defined yet.

AIM

A cross-sectional observational study was conducted to evaluate the prevalence of both symptomatic and asymptomatic catheter-associated thrombosis events in children affected with different solid tumors.

METHODS

Patients with a solid tumor, admitted as day-care, were consecutively enrolled over a period of 10 months. All of them had a central venous line. Physical examination, D-dimer serum tests, and eco-color-Doppler ultrasonography were performed once at any time before catheter removal.

RESULTS

Forty-two patients (14 females and 28 males)-mean age 115 months-were evaluated. Five of the 42 patients (12%) had VT. In 4 of these, VT was catheter-related: 3 asymptomatic and 1 symptomatic. In the last patient, VT was clinically symptomatic and not catheter related. Patients with longer duration of catheter insertion presented with a higher rate of VT (P=0.05). Moreover, patients affected with neuroblastoma showed a higher rate of VT than the others with different solid tumors (P<0.05).

CONCLUSIONS

VT was visualized by echo-color-Doppler ultrasonography in 12% of the patients; it was asymptomatic in 7%. In our small series, VT was related to neuroblastoma disease and a longer duration of catheter insertion. Prospective and multicentric studies are required to select risk factors for VT in children with solid tumors.

Complications of Implanted Central Venous Catheters in Neutropenic Children

Although neutropenia is recognized as a risk factor for infection and compromised wound healing, there are little data regarding the specific impact of neutropenia on morbidity and mortality after placement of implanted central venous catheters (CVC). We conducted a retrospective review of children with a diagnosis of acute lymphocytic leukemia or aplastic anemia who received a CVC over a 5-year period. The absolute neutrophil count immediately before catheter placement was recorded. Three hundred eight catheters were placed in 195 patients with acute lymphocytic leukemia and 15 with aplastic anemia. Absolute neutrophil count was less than 0.5 x 109/L in 105 cases (Group 1). The incidence of CVC removal for all causes and for infection within 100 days in Group 1 was 17.1 per cent and 11.4 per cent, respectively, compared with 7.9 per cent ( P = 0.01) and 1.5 per cent ( P < 0.0001) with absolute neutrophil count 0.5 x 109/L or greater (Group 2). Infections included two cases of mucormycosis with one death. Ports were more likely than Hickman catheters (C. R. Bard Inc., Murray Hill, NJ) to be removed for all causes ( P = 0.01) and for infection ( P = 0.04). The placement of implanted central venous catheters in neutropenic children was associated with substantial infectious morbidity and one death. When possible, CVC, particularly ports, should be avoided in the presence of neutropenia.

Thromboembolism in children with sarcoma

BACKGROUND

Thromboembolism (TE) is a common complication and cause of death in adults with cancer. Cancer has been identified as a major risk factor in children with TE. However, the information regarding the epidemiology of TE in children with cancer, especially in association with childhood solid tumors, is scant.

OBJECTIVE

To define the prevalence and epidemiology of TE in children with sarcoma.

PROCEDURE

Hospital records of children </=18 years of age with sarcoma diagnosed and treated at McMaster Children's Hospital during January 1990 to December 2005 were reviewed for demographic details, details of diagnosis and therapy for sarcoma, and details of diagnosis and management of TE. Statistical analysis was performed using Fisher's exact t-test.

RESULTS

Ten of 70 (14.3%; 95% CI; 7.1, 24.7) patients with sarcoma developed symptomatic TE. Patients with CVL-dysfunction (n = 9) were at significantly higher risk for symptomatic TE compared to those without CVL dysfunction (n = 61) (55.5 vs. 8.2%; P = 0.002, 95% CI; 14.2, 80.5). Patients with pulmonary disease (n = 23) had higher prevalence of TE compared to those without pulmonary disease (n = 47) (26 vs.8.5%; P = 0.07, 95% CI; -2.06, 37.2). Older patients, patients with metastatic disease and those with Ewing sarcoma had higher prevalence of TE.

CONCLUSIONS

TE is a significant complication in children with sarcoma. Over 50% of patients with CVL dysfunction had symptomatic TE; such patients may warrant careful evaluation for associated TE. Large prospective studies are needed to define the epidemiology and identify risk factors predisposing to TE in children with sarcoma.

Port-A-Cath insertions in acute leukemia: does thrombocytopenia affect morbidity?

BACKGROUND

Unnecessary delay of insertion of Port-A-Cath indwelling venous catheters in thrombocytopenic patients may result from fear of potential morbidity. This study sought to compare the morbidity of Port-A-Cath insertions in acute leukemic patients with platelet counts below and above 50 x 10(9)/L.

METHOD

Incidence and profile of catheter-related bloodstream infections (CRBSIs) and other complications were determined in 80 consecutive Port-A-Cath insertions in pediatric patients with acute leukemia from January 2002 to December 2004. Subgroup analysis was performed for patients with platelet levels below and above the recommended safe level of 50 x 10(9)/L.

RESULTS

Twenty-two (27.5%) patients had insertions performed at platelet levels below the recommended level (median, 35.3; range, 10-49 x 10(9)/L); postoperative counts were correspondingly higher (median, 66.0; range, 20-207 x 10(9)/L) with perioperative platelet transfusion. Catheter-related bloodstream infection incidence was similar in patients with platelets less than and greater than the recommended threshold (18.2% vs 17.2%, respectively), and likewise for CRBSIs encountered in the immediate 30 postoperative days (4.6% and 5.2%, respectively). Only 2 episodes of postoperative bleeding occurred, both in the group with platelet counts greater than 50 x 10(9)/L, with an equally low incidence of other local and mechanical complications in both subgroups. Patient demographics and other preoperative blood parameters did not differ significantly.

CONCLUSION

Preoperative thrombocytopenia was not associated with increased incidence of postoperative complications for Port-A-Cath insertions in acute leukemic children.

Port-A-Cath Insertions in Acute Leukaemia and Childhood Malignancies

OBJECTIVE

This retrospective case series sought to determine the incidence and profile of catheter-related complications associated with Port-A-Cath insertions in paediatric cancer patients, as well as predictive factors for infection-related port removals.

METHODS

Between January 2002 and December 2004, 175 consecutive Port-A-Cath insertions were followed for a total of 75,000 days (median, 407; range, 6-1,074). Incidence of catheter-related bloodstream infections (CRBSIs), other complications and CRBSI-related port removals were analysed for cases with acute leukaemia versus other malignancies.

RESULTS

A total of 33 CRBSIs were encountered in 26 cases (18.9%), an infection rate of 0.44 episodes per 1,000 catheter days. While mean preoperative platelet count was 125.34 x 10(9)/L in children with acute leukaemia and 392.11 x 10(9)/L in those with other malignancies (p < 0.01), the incidence of all complications were similar between both subgroups. Staphylococcus epidermidis (23.1%) and Klebsiella spp. (19.2%) were most commonly isolated from infected ports. Median patient age and duration of implantation in CRBSI-related port removals was 1.5 years and 111 days respectively, and 10.0 years and 414 days respectively in CRBSIs without port removal.

CONCLUSION

Minimal complications are associated with Port-A-Cath insertions, even in thrombocytopaenic leukaemic patients. The dominance of Gram-negative organisms in CRBSIs parallels the changing trend of nosocomial infectious agents involved in catheter-related infections.

Thrombosis and acute lymphoblastic leukaemia

Venous thrombosis is more frequent in patients treated for acute lymphoblastic leukaemia (ALL) than other malignancies and has distinctive causes, clinical features and remedies. The reported incidence varies from 1% to 36%, depending on the chemotherapy protocol and whether the reported cases are symptomatic or detected on screening radiography. The risk is thought to arise from increased thrombin generation at diagnosis combined with reduced thrombin inhibitory capacity due to depletion of circulating anti-thrombin (AT) by asparaginase. A number of patient and treatment variables have been reported to influence the risk of thrombosis including hereditary thrombophilia, early insertion of central venous catheters and exposure to a combination of steroids and asparaginase during induction. Erwinia asparaginase is associated with a lower risk of thrombosis compared with Escherichia coli asparaginase. The majority of symptomatic thromboses are related to central venous catheters and involve the upper venous system. Central nervous system thrombosis involving the cerebral venous sinuses is a unique feature of asparaginase-related thrombosis and is reported to occur in 1-3% of patients. Conclusive evidence to support the use of anti-coagulant treatment or AT concentrates for primary prevention is lacking, as is evidence for the efficacy of AT concentrates in the management of established thrombosis. Preventative strategies are hampered by conflicting data on factors that would enable identification of those at highest risk of thrombosis.

The safety of central line placement prior to treatment of pediatric acute lymphoblastic leukemia

BACKGROUND

Central venous lines are placed in children with acute lymphoblastic leukemia at diagnosis, despite significant cytopenias, to facilitate the administration of chemotherapy and blood sampling. The present study aimed to determine the safety of central line placement in these patients.

METHODS

We reviewed the charts of 115 consecutive patients treated during a 10-year period. Data abstracted comprised age, gender, presenting and preoperative blood counts, type of central line, blood products transfused preoperatively, duration of neutropenia (absolute neutrophil count [ANC], <500/microl), treatment, and central line-associated complications.

RESULTS

There were 66 male and 49 female patients with a median age of 4 years. Seventy-one patients were classified as standard-risk and 44 as high-risk. Respective median blood counts at diagnosis and prior to surgery were white cell count (microl), 4,200 and 5,550; hemoglobin (g/dl), 7.7 and 9.4; platelet count (microl), 63,000 and 72,000; and ANC (microl), 3,950 and 4,900. The median duration of neutropenia was 15 days in the standard-risk group and 18 days in the high-risk group. Thirty-eight patients were not transfused preoperatively. There were no episodes of bacteremia. Seven patients (7%) with life-ports experienced a complication: in four blood could not be aspirated, two ports needed realignment, and one a wound infection developed without dehiscence. Four patients (27%) with external lines had a complication: one each with line occlusion, accidental removal by patient, line rupture, and line leakage at insertion site. The complication rate between ports and external lines was different (P = 0.045).

CONCLUSIONS

Central line placement prior to anti-leukemia treatment is safe. Most complications are mechanical and not due to leukemia, chemotherapy, or cytopenias.

Extent of agreement in gentamicin concentration between serum that is drawn peripherally and from central venous catheters

OBJECTIVE

At our institution, patients who receive once-daily dosing of gentamicin have serum concentrations determined 3 and 6 hours after dose administration. Patients with single-lumen central venous catheters have the 3-hour samples drawn peripherally. The objective of this study was to evaluate the extent of agreement between peripheral and central venous catheter serum gentamicin concentrations drawn 3 hours after dose administration.

METHODS

In this prospective, observational study, patients provided both a peripheral and a central blood sample for determination of serum gentamicin concentration. The order of sampling (central venous catheter versus peripheral first) was randomized. Agreement was assessed by determination of the intraclass correlation coefficient and Bland-Altman analysis. The clinically acceptable targets for the lower limit of the intraclass correlation coefficient and Bland-Altman limits of agreement were defined a priori as >0.80 and +/-6%, respectively. Differences between the theoretical dose adjustments using the central venous catheter versus the peripheral sample result were described.

RESULTS

Forty-five pairs of samples were collected: 42 from single-lumen implantable central venous catheters (ports) and 3 from peripherally inserted central venous catheters. The intraclass correlation coefficient was 0.91. However, the Bland-Altman analysis resulted in a mean percentage difference (central venous catheter versus peripheral) of -0.92% and limits of agreement of -27.9% to 26.0%. The gentamicin dose adjustment based on the central venous catheter sample result would have led to clinically significant dose adjustments in 19 (42%) cases, when compared with the peripheral sample result.

CONCLUSIONS

These results indicate a lack of agreement between peripheral and single-lumen central venous catheter samples. In particular, ports are not appropriate sites for monitoring serum gentamicin concentrations.

Thromboembolic complications in children with cancer

Thrombosis is a significant problem in patients with cancer. The impact of thromboembolism in association with childhood cancer is not clearly defined. Similarly the information of prevention and management of thromboembolic events in children receiving cancer-therapy is limited. This review aims to examine current knowledge regarding the epidemiology, pathophysiology and management of thrombosis in association with cancer in children.