Pneumonectomy: The final cut in a rare incidence of persistent bronchopleural fistula following empyema.

The incidence of necrotizing pneumonia and empyema complicated by bronchopleural fistula is rising. We describe the case of a 2-year-old boy who presented with empyema thoracis and necrotizing pneumonia who developed a bronchopleural fistula. At initial thoracotomy for decortication, necrotic lung was found and resected. He subsequently underwent further thoracotomy, prolonged chest tube drainage and endobronchial glue application attempts to close a bronchopleural fistula. The fistula was only sealed at third thoracotomy and completion pneumonectomy. This case highlights the potential challenges faced when dealing with air leaks in the setting of infection and we discuss the treatment options available.

The interrupter technique to assess airway responsiveness in children with cystic fibrosis.

The aim of this study was to assess the validity of the interrupter technique (Rint) in measuring airway responsiveness in children with cystic fibrosis. Fifty children (aged 6-16 years) with cystic fibrosis performed six Rint measurements followed by three acceptable forced expiratory maneuvers. Each child then inhaled 5 mg of nebulized salbutamol by facemask. After 20 min the Rint and forced expiratory measurements were repeated. In the population as a whole a moderate but significant correlation between inverse Rint and FEV1 values was observed, both before and after inhaled bronchodilator (r=0.71 and 0.72, respectively, P < 0.001). However, when changes in Rint and FEV1 readings following inhaled bronchodilator were examined, no relationship was seen. Indeed, the two methods identified completely different subsets of children as being bronchodilator responsive. These results indicate that although a relationship exists between Rint and FEV1 in the whole population, this is not the case in individual children. Rint and FEV1 reflect different aspects of lung function. It is not appropriate to use Rint as a simple alternative for FEV1 in children with cystic fibrosis when assessing airway responsiveness.

The measurement of airways resistance using the interrupter technique (Rint).

The interrupter technique (Rint) is a quick, easy and effort-independent way to obtain indirect measurements of airways resistance in the preschool child. Results may be obtained using a portable Rint machine or a whole-body plethysmograph. Normative data are available and recent studies have improved standardisation of the methodology. Despite this, between-occasion results can be variable, particularly in children with wheeze. This limits the usefulness of the test in the assessment of long-term interventions such as the administration of inhaled steroids. The most useful role for Rint, therefore, appears to be in the assessment of bronchodilator responsiveness where it is as sensitive as spirometry in separating children with reversible airways disease from healthy controls. This paper describes the physiology of the interrupter technique and the methodology needed to obtain reliable results. Normal ranges are provided. The clinical applicability, repeatability, strengths and limitations of the technique are also discussed.

The association of maternal but not paternal genetic variation in GSTP1 with asthma phenotypes in children.

Maternal factors including atopy and smoking during pregnancy are associated with asthma risk during childhood. Suggested mechanisms include transmission of specific maternal alleles and maternal influences on the intrauterine environment. We have previously shown that polymorphism in glutathione S-transferase, GSTP1 is associated with airway hyperresponsiveness (AHR) and atopy in adults. We now hypothesise that GSTP1 genotypes in the mother and child, but not the father, mediate asthma phenotypes in the child. One hundred and forty-five Caucasian families were recruited via an asthmatic proband aged 7-18 years. Atopy and asthma were assessed using a questionnaire, skin prick testing, serum IgE, spirometry and methacholine challenge (PC20, dose-response slope--DRS). GSTP1 genotyping was determined using PCR. GSTP1 Val105/Val105 genotype in the child was associated with a reduced risk of atopy (P = 0.038) and AHR (PC20, P = 0.046; DRS, P = 0.032). In mothers (P = 0.014) but not fathers (P = 0.623), Val105/Val105 was associated with a reduced risk of AHR in the child. We have identified, for the first time, an association between maternal genotype and the child's asthma phenotype that appears not to be due to transmission of specific maternal alleles. This preliminary data supports the view of in utero effects of maternal genotype and adds new insights into the possible mechanisms by which maternal factors may influence development of childhood asthma.

Correction of bronchial challenge data for age and size may affect the results of genetic association studies in children.

Meaningful studies of asthma genetics require careful definition of airway hyperresponsiveness (AHR). In children, several studies have emphasized the need for correction of bronchial challenge data for baseline parameters, such as age, gender, lung function and atopic status, when undertaking airway responsiveness measurements. However, few studies have suggested how this should be performed in practice. This study describes a method for the correction of dose-response slopes (DRS) and PC20 values for baseline parameters in children, and illustrates the effect of such corrections on the association of AHR with the glutathione S-transferase GSTP1 Ile105Val polymorphism in children. Skin prick and methacholine challenge testing, measurement of total serum IgE concentration and GSTP1 genotyping were performed in 145 unrelated British children aged 7-18 years. Correction of bronchial challenge results, expressed as both DRS and PC20 values, for age, gender, baseline lung function and atopic status was performed using linear regression and discriminant analysis, respectively. Adjusting bronchial challenge results for the age and size of the child altered AHR status, defined as a PC20 methacholine <8 mg/ml, in 37% of children. Correction for baseline parameters also resulted in a significant reduction in mean DRS (original uncorrected DRS 83.6, corrected DRSc 27.4). This had a marked effect on the results of the association study, unmasking a previously unidentified association between the GSTP1 genotype and AHR in children. Age and size adjustment of bronchial challenge data has a significant effect on AHR status and may influence the results of genetic association studies in children.