Improvements in Cystic Fibrosis Quarterly Visits, Lung Function Tests, and Respiratory Cultures.

BACKGROUND: The Cystic Fibrosis (CF) Foundation recommends patients attend clinic ≥4 times per year with 4 respiratory cultures and 2 pulmonary function tests (PFTs). However, nationally only 57.4% of patients met these guidelines in 2012. We used a quality improvement program with a goal of 75% of our patients meeting this care guideline by 2012. METHODS: A 2-stage program was started in 2011. Stage 1: education of patients/caregivers on importance of quarterly visits. Stage 2: quarterly tracking system of patient appointments. Data on clinic visits, respiratory cultures, and PFTs were collected from the CF registry from January 2009 through December 2013. Statistical process control charts were used to track improvements. RESULTS: The average number of clinic visits increased significantly from 4.6 ± 2.3 in 2009 to 6.3 ± 4.6 in 2013 (P < .0001). The percentage of patients ages 6 through 18 completing a clinic visit, PFT, and respiratory culture per quarter increased significantly from 76.2% during 2009 to 86.4% in 2013. The percentage of patients completing ≥4 clinic visits with 4 respiratory cultures and 2 PFTs improved significantly from 47.5% in 2009 to 71.0% in 2013 (P < .0001). CONCLUSIONS: A tracking system of patient appointments significantly improved adherence to the care guidelines better than education alone. The multiple-stage quality improvement program we implemented may be modifiable and able to be integrated in other CF centers or other multiple disciplinary chronic illness care centers.

Population pharmacokinetics of intermittent vancomycin in children with cystic fibrosis.

BACKGROUND: Vancomycin is the drug-of-choice for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in children with cystic fibrosis. However, no studies have characterized the pharmacokinetic profile of vancomycin among pediatric cystic fibrosis patients. OBJECTIVE: To evaluate the pharmacokinetics of intermittent vancomycin administration in children with cystic fibrosis and identify covariates that significantly influence vancomycin efficacy and safety. METHODS: Therapeutic drug monitoring data were obtained from two cystic fibrosis care centers that identified children < 18 years who received vancomycin treatment for an acute pulmonary exacerbation from 2005 to 2010. Trough and peak serum concentrations were determined before and after the third or fourth dose. Nonlinear mixed effects models were developed to evaluate the population pharmacokinetics of vancomycin. RESULTS: Among the 67 children (mean age 12.1 ± 5.3 years), the mean vancomycin dose was 17.4 ± 4.4 mg/kg. The mean trough concentration (Cmin ) was 10.3 ± 3.8 mg/L. The mean daily area under the serum concentration time curve (AUC24 ) was 282.5 ± 816.9 mg·hour/L. A one-compartment model with first-order elimination best described the data. Weight significantly influenced vancomycin clearance (p<0.001). In the final model, clearance was estimated as 5.57 L/hour/70 kg, and the volume of distribution was 44.1 L/70 kg. The between subject variability for clearance and volume of distribution were 27% and 40%, respectively. CONCLUSIONS: Using a one-compartment model to evaluate the pharmacokinetic properties of vancomycin in children with cystic fibrosis, clearance increased with body weight. Pharmacodynamic studies are needed to establish an optimal vancomycin dosing regimen for the treatment of pediatric exacerbations of cystic fibrosis.

Vocal cord dysfunction in children.

Vocal cord dysfunction is characterised by paradoxical vocal cord adduction that occurs during inspiration, resulting in symptoms of dyspnoea, wheeze, chest or throat tightness and cough. Although the condition is well described in children and adults, confusion with asthma often triggers the use of an aggressive treatment regimen directed against asthma. The laryngoscopic demonstration of vocal cord adduction during inspiration has been considered the gold standard for the diagnosis of vocal cord dysfunction, but historical factors and pulmonary function findings may provide adequate clues to the correct diagnosis. Speech therapy, and in some cases psychological counselling, is often beneficial in this disorder. The natural course and prognosis of vocal cord dysfunction are still not well described in adults or children.

Allergic bronchopulmonary aspergillosis in a patient with cystic fibrosis: diagnostic criteria when the IgE level is less than 500 IU/mL.

BACKGROUND: Recently, the Cystic Fibrosis Foundation developed a consensus report recommending diagnostic criteria for allergic bronchopulmonary aspergillosis (ABPA) in patients with cystic fibrosis that includes a serum IgE level greater than 500 IU/mL as the "minimal diagnostic criterion." OBJECTIVE: To describe a 7-year-old girl with ABPA whose serum IgE level increased to only 398 IU/mL. METHODS: Total IgE and anti-Aspergillus serologic measurements were performed using enzyme-linked immunosorbent assay and standard laboratory techniques; HLA analysis was performed; interleukin 4 receptor alpha single nucleotide polymorphisms were performed using polymerase chain reaction and DNA sequencing; CD23+ B cells were measured using flow cytometry; and cytokine synthesis to Aspergillus purified antigens was assessed using flow cytometry. RESULTS: A 7-year-old girl with cystic fibrosis who had mild pulmonary disease and well-controlled asthma developed pulmonary infiltrates, increased wheezing, and decreased pulmonary function. Additional studies demonstrated peripheral blood eosinophilia (eosinophil count, 1807 cells/mm3 [19%]) and an increase in IgE and IgG anti-Aspergillus serology; bronchoalveolar lavage revealed septate hyphae with 45 degrees branching subsequently identified as A fumigatus and pulmonary eosinophilia. Previous HLA typing revealed that the patient was HLA-DR2+, DRB*1501, HLA-DQ2-, a pattern associated with increased risk of ABPA. In addition, there was increased up-regulation of CD23 molecules by interleukin 4 stimulation on the patient's B cells, as observed in ABPA. The patient was treated with corticosteroids and itraconazole with resolution of symptoms and pulmonary infiltrates. CONCLUSIONS: Examination of the pulmonary inflammatory response using bronchoalveolar lavage, genetic risk with HLA-DR2+DQ2- typing, and increased interleukin 4 sensitivity are useful adjunctive studies in the diagnosis of ABPA.

Pericardial cysts in children: surgical or conservative approach?

The authors present a case of an 11-year-old boy with a history of mild asthma and cough who underwent radiographic examination of the chest. The radiograph showed a round, discrete mass in the right cardiophrenic angle. The patient underwent thoracoscopic excision, and histologic examination found a unilocular, pericardial cyst. The possible causes of mediastinal masses and an argument for their surgical removal is presented.