Ian MacLusky

Pseudomonas cepacia infection in cystic fibrosis: An emerging problem

The prevalence of Pseudomonas cepacia infection increased from 10% in 1971 to 18% by 1981 in a population of approximately 500 patients with cystic fibrosis. Carriage of P. aeruginosa has remained unchanged at 70% to 80% over the same period. Patients infected with P. cepacia have greater impairment of pulmonary function than those with P. aeruginosa. A syndrome characterized by high fever, severe progressive respiratory failure, leukocytosis, and elevated erythrocyte sedimentation rate has occurred in eight patients over the past 3 years, with a 62% fatality rate. Because P. cepacia strains are uniformly resistant to ticarcillin, piperacillin, and aminoglycosides, and because ceftazidime is ineffective despite in vitro activity, treatment of these infections is very difficult. Prevention of acquisition and effective treatment of P. cepacia in patients with cystic fibrosis are now major clinical problems in our clinic.

Inhaled antibiotics in cystic fibrosis: Is there a therapeutic effect?

Antibiotics are administered to patients with cystic fibrosis to eliminate or suppress sputum bacteria. Aerosol administration is attractive because it delivers antibiotic directly to the site of infection. Effective aerosol administration is compromised by the inefficiency of nebulizers to generate small-particle aerosols, adverse airway reaction to the drug, potential emergence of resistant bacteria, and cost. Studies evaluating aerosol treatment have not always controlled for confounding factors and have used a variety of outcome indicators. Results of controlled studies are contradictory with regard to the beneficial effect of aerosol therapy on pulmonary function, sputum bacterial density, and frequency of hospitalization. Therefore, until additional well-controlled trials are completed, routine aerosol administration of antibiotics in cystic fibrosis is not warranted because of cost, potential side effects, and the propensity to select resistant organisms.

Utility of Contrast Echocardiography for Pulmonary Arteriovenous Malformation Screening in Pediatric Hereditary Hemorrhagic Telangiectasia

OBJECTIVEnTo evaluate the utility of transthoracic contrast echocardiography (TTCE) as a screening tool for pulmonary arteriovenous malformations (PAVMs) in children with hereditary hemorrhagic telangiectasia (HHT).nnnSTUDY DESIGNnThis was a single-center study of children who underwent baseline screening for PAVMs using both TTCE and chest computed tomography (CT) for evaluation of HHT. The CT and TTCE results were prospectively reviewed independently by 2 radiologists and 2 cardiologists blinded to the study results.nnnRESULTSnBoth intraobserver and interobserver agreement for interpreting TTCE results were excellent (κ = 0.97 and 0.92, respectively) and higher than the interobserver agreement for CT interpretation (κ = 0.75). The sensitivity and specificity of TTCE to predict PAVMs were 1 and 0.82, respectively, and the positive predictive and negative predictive values were 0.39 and 1, respectively.nnnCONCLUSIONnTTCE is a sensitive test for PAVMs in children with suspected HHT and can be a useful initial screening tool in pediatric HHT.

Hemoptysis: a rare cause can be related to a bronchial varix due to pulmonary venous obstruction.

Bronchial varices, which have rarely been described in the radiology literature, can be the result of pulmonary venous obstruction and may present with hemoptysis. This case is an illustration of this rare condition, which correlates CT findings with bronchoscopic findings. We also describe the findings on phase-contrast MR that demonstrated reversed diastolic flow in the branch pulmonary artery supplying the affected lung.

Presentation and Treatment of Monozygotic Twins with Congenital Central Hypoventilation Syndrome

Congenital central hypoventilation syndrome is a rare genetic disorder characterized by hypoventilation during sleep secondary to a blunted response to hypercapnia and hypoxia. The current case report describes developmentally normal four-year-old monozygotic twin boys who presented in infancy with variable presentations and clinical severity of congenital central hypoventilation syndrome. Both were managed with noninvasive positive pressure ventilation.