Dennis C. Stokes

in situ management of confirmed central venous catheter-related bacteremia

Thirty-one patients with suspected central venous catheter-related bacteremia were evaluated with comparative quantitative cultures of central venous and peripheral blood specimens. Using criteria developed from studies in bacteremic animals, 19 patients were confirmed to have catheter-related bacteremia. Antibiotic therapy was administered through the catheter (in situ therapy) in 17 of those patients to evaluate the feasibility of treating patients with true central venous catheter-related bacteremias without catheter removal. Bacteremia was successfully eradicated in 11 of 17 patients (65%), allowing 7 patients to retain their catheter a median of 157 days. This study validates the use of comparative quantitative blood cultures in the diagnosis of catheter-related bacteremia and indicates that in situ therapy is a rational alternative to catheter removal in patients with catheter-related bacteremia.

A Prospective Study of Hickman/Broviac Catheters and Implantable Ports in Pediatric Oncology Patients

We prospectively studied the continuous function and complication rates of 286 central venous catheters consecutively placed in 264 children and young adults at a single institution over a 19-month period (median follow-up, 376 days). Externalized catheters (91 Hickman [H], 113 Broviac [B]) and implantable ports (n = 82) were compared for complications, including infection and thrombosis. The most frequent major complication of all catheters was infection, although the rates of infection varied with the duration of catheter use and were generally lower than reported by others. Overall, when catheter failures (removal) for infection, obstruction, or dislodgement were considered, ports had a significantly longer failure-free duration of use (P = .0024) than did externalized catheters. Likewise, ports had a significantly longer infection-free (P less than .01) duration of use than H and B catheters. However, differences in patient age and clinical characteristics among the three catheter groups may have affected the outcome. In analysis of pairs matched for diagnosis, therapy, and age, ports had lower infection rates than did B catheters after 100 days (P = .053). This difference became significant at 400 days of catheter use (P = .029). Although there was a trend toward lower rates of infections for ports v H catheters, this difference was not significant. In view of our results in matched pairs, selection of catheter type based on clinical characteristics and patient preferences remains a reasonable therapeutic approach despite the apparent advantages of ports. The superiority of ports for long-term use (greater than 100 days) needs to be confirmed in a large randomized clinical trial.

Respiratory complications of achondroplasia

Nine patients with achondroplasia who were seen over a three-year period developed significant respiratory complications. Eight had sleep-disordered breathing, including obstructive sleep apnea in five, for which two required tracheostomy. Of the seven patients with significant hypoxemia, five had clinical evidence of cor pulmonale and recurrent pulmonary infiltrates. Two patients died, one with autopsy findings of compression of the medulla at the level of the foramen magnum and one with respiratory and cardiac failure. Appropriate therapy for our patients depended on recognition of the mechanisms that led to the respiratory complications, including (1) chest deformity, (2) upper airway obstruction and sleep-disordered breathing, (3) neurologic complications, and (4) coincidental chronic pulmonary conditions such as asthma.

Immunogenicity of a new purified fusion protein vaccine to respiratory syncytial virus: A multi-center trial in children with cystic fibrosis

A third generation, purified fusion protein (PFP-3) vaccine was developed to prevent severe respiratory syncytial virus (RSV) disease in high-risk groups. A phase II, multi-center, adjuvant-controlled trial was performed in RSV seropositive children with cystic fibrosis (CF); 151 received the adjuvant-control and 143 received the vaccine. Details of the vaccine-induced immune response are presented. At enrollment, RSV-specific, serum antibodies were comparable between both groups. A highly sensitive and specific serum antibody vaccine profile was established for the PFP-3 vaccine. At post-vaccination and end-of-study, RSV-specific, neutralizing antibody (Nt Ab) and binding antibody (Bd Ab) to the fusion (F) protein were significantly higher in PFP-3 vaccinees. After 28 days post-vaccination, Nt Ab and Bd Ab to F protein titers declined slowly at rates of 0.23 and 0.37 log2 per month, respectively. The PFP-3 vaccine-induced a robust immune response that lasted throughout the RSV season.

Pulmonary Outcomes in Survivors of Childhood Cancer: A Systematic Review

BACKGROUND The purpose of this article is to summarize the literature that documents the long-term impact of cancer treatment modalities on pulmonary function among survivors of cancer and to identify potential areas for further research. METHODS Systematic reviews of clinical trials, observational studies, case series, and review articles were conducted. Articles were limited to the studies that discussed pulmonary toxicity or late effects among pediatric cancer survivors and to follow-up investigations that were conducted a minimum of 2 years after completion of cancer-related treatment or 1 year after hematopoietic stem cell transplant. RESULTS Sixty publications (51 clinical studies/reports and nine reviews) published from January 1970 to June 2010 in PubMed met the inclusion criteria. Data showed an association between radiotherapy, alkylating agents, bleomycin, hematopoietic stem cell transplant, and thoracic surgery and pulmonary toxicity, as well as possible interactions among these modalities. CONCLUSIONS Pulmonary toxicity is a common long-term complication of exposure to certain anticancer therapies in childhood and can vary from subclinical to life threatening. Pulmonary function and associated loss of optimal exercise capacity may have adverse effects on long-term quality of life in survivors. Lung function diminishes as a function of normal aging, and the effects of early lung injury from cancer therapy may compound these changes. The information presented in this review is designed to provide a stimulus to promote both observational and interventional research that expands our knowledge and aids in the design of interventions to prevent or ameliorate pulmonary late effects among survivors of childhood cancer.

Role of flexible bronchoscopy in the diagnosis of pulmonary infiltrates in pediatric patients with cancer

We reviewed 60 consecutive flexible bronchoscopies done during a 36-month period in 48 pediatric cancer patients with undiagnosed pulmonary infiltrates. Diagnostic procedures during bronchoscopy included 40 brushings, 50 bronchoalveolar lavages, and 6 transbronchial and mucosal biopsies. A total of 16 specific diagnoses were made by bronchoscopy (27% diagnostic yield), including infection (12), pulmonary leukemia (3), and lymphoma (1). The largest proportion of specific diagnoses came from lavage (14/50) and the smallest from brushings (1/40). Biopsies were also useful for selected patients. The low overall yield for bronchoscopy was probably due to the routine use of empiric broad-spectrum antibiotics and antifungal therapy, as well as trimethoprim-sulfamethoxazole prophylaxis for Pneumocystis carinii pneumonitis. Subsequent specific diagnoses were obtained by other procedures (open biopsy, needle aspiration, or autopsy) for 10 patients with negative bronchoscopy results and 3 patients with diagnostic bronchoscopies. These additional diagnoses included 7 infections (Pneumocystis carinii (1), Candida tropicalis (1), cytomegalovirus (1), and Aspergillus (4), and 6 other diagnoses with nonspecific histologic findings. A positive bronchoscopy result may be useful, but negative bronchoscopy findings do not justify delaying other diagnostic procedures or discontinuing antibiotic and antifungal therapy in children with cancer and pulmonary infiltrates.

Effect of scavengers of oxygen-derived free radicals on mortality in endotoxin-challenged mice

Oxygen-derived free radicals have been implicated as mediators of cellular injury in several model systems. Recently, a role for free radicals has been proposed in the mortality associated with Gram-negative bacterial sepsis. To determine if pretreatment with free radical scavengers can prevent endotoxin-induced mortality, mice rendered sensitive to endotoxin with actinomycin D were treated with either superoxide dismutase (SOD), N-acetylcysteine (NAC) or saline and were then challenged with a dose of endotoxin calculated to cause a mortality of greater than 80%. Mortality was assessed at 12-h intervals after challenge. Increased survival was seen in the SOD-treated group compared to the control group (p less than or equal to .05). In contrast, survival in mice treated with NAC, another potential scavenger, was not significantly different from the control group. These results support the hypothesis that superoxide and hydroxyl radicals contribute to mortality in Gram-negative bacterial sepsis.

Serial pulmonary function studies in children treated for newly diagnosed Hodgkin's disease with mantle radiotherapy plus cycles of cyclophosphamide, vincristine, and procarbazine alternating with cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine

Background. The pulmonary toxicity of bleomycin‐containing chemotherapy combined with mantle radiotherapy in children treated for Hodgkins disease was longitudinally assessed.

Chronic obstructive airways disease after bone marrow transplantation

The clinical course, serial pulmonary function studies, lung histopathologic findings, and treatment in two patients after bone marrow transplantation for acute monoblastic leukemia or aplastic anemia are presented. The course in one patient has been slowly progressive for 2 years and characterized by chronic obstructive airways disease and recurrent pneumothoraces. Histopathologic changes were nonspecific, characterized by chronic interstitial pneumonitis and interstitial fibrosis. In the second patient there was insidious onset of disease with increasing dyspnea on exertion and rapid clinical deterioration; he died within 4 months of severe obstructive airways disease. Necrotizing bronchitis and bronchiolitis characterized the lung findings. Neither patient responded to conventional bronchodilator therapy, and prednisone was the only agent to produce subjective, though transient, improvement. Symptomatic obstructive airways disease associated with chronic graft-versus-host disease is emerging as a potentially major cause of morbidity and mortality after marrow transplantation.

Pulmonary Dysfunction in Survivors of Childhood Hematologic Malignancies after Allogeneic Hematopoietic Stem Cell Transplantation

The number of long‐term survivors of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is increasing; however, few studies have addressed their long‐term pulmonary function.