Spirometry and Impulse Oscillometry in Preschool Children: Acceptability and Relationship to Maternal Smoking in Pregnancy.

BACKGROUND: Comparisons of the technical acceptability of spirometry and impulse oscillometry (IOS) and clinical correlations of the measurements have not been well studied in young children. There are no large studies focused on African American and Hispanic children. OBJECTIVES: We sought to (1) compare the acceptability of spirometry and IOS in 3- to 5-year-old children and (2) examine the relationship of maternal smoking during pregnancy to later lung function. METHODS: Spirometry and IOS were attempted at 4 sites from the Urban Environmental and Childhood Asthma Study birth cohort at ages 3, 4, and 5 years (472, 471, and 479 children, respectively). We measured forced expiratory flow in 0.5 s (forced expiratory volume in 0.5 seconds [FEV0.5]) with spirometry and area of reactance (AX), resistance and reactance at 5 Hz (R5 and X5, respectively) using IOS. RESULTS: Children were more likely to achieve acceptable maneuvers with spirometry than with IOS at age 3 (60% vs 46%, P < .001) and 5 years (89% vs 84%, P = .02). Performance was consistent among the 4 study sites. In children without recurrent wheeze, there were strong trends for higher FEV0.5 and lower R5 and AX over time. Maternal smoking during pregnancy was associated with higher AX at ages 4 and 5 years (P < .01 for both years). There was no significant difference in FEV0.5 between children with and without in utero exposure to smoking. CONCLUSION: There is a higher rate of acceptable maneuvers with spirometry compared with IOS, but IOS may be a better indicator of peripheral airway function in preschool children.

Hyperpolarized Helium-3 MRI of exercise-induced bronchoconstriction during challenge and therapy.

PURPOSE: To investigate the utility of hyperpolarized He-3 MRI for detecting regional lung ventilated volume (VV) changes in response to exercise challenge and leukotriene inhibitor montelukast, human subjects with exercise induced bronchoconstriction (EIB) were recruited. This condition is described by airway constriction following exercise leading to reduced forced expiratory volume in 1 second (FEV1) coinciding with ventilation defects on hyperpolarized He-3 MRI. MATERIALS AND METHODS: Thirteen EIB subjects underwent spirometry and He-3 MRI at baseline, postexercise, and postrecovery at multiple visits. On one visit montelukast was given and on two visits placebo was given. Regional VV was calculated in the apical/basilar dimension, in the anterior/posterior dimension, and for the entire lung volume. The whole lung VV was used as an end-point and compared with spirometry. RESULTS: Postchallenge FEV1 dropped with placebo but not with treatment, while postchallenge VV dropped more with placebo than treatment. Sources of variability for VV included region (anterior/posterior), scan, and treatment. VV correlated with FEV1/ forced vital capacity (FVC) and forced expiratory flow between 25 and 75% of FVC and showed gravitational dependence after exercise challenge. CONCLUSION: A paradigm testing the response of ventilation to montelukast revealed both a whole-lung and regional response to exercise challenge and therapy in EIB subjects.

Factors influencing emergency department preference for access to healthcare.

INTRODUCTION: African-Americans are more likely than Caucasians to access healthcare through the emergency department (ED); however, the reasons behind this pattern are unclear. The objective is to investigate the effect of race, insurance, socioeconomic status, and perceived health on the preference for ED use. METHODS: This is a prospective study at a tertiary care ED from June to July 2009. Patients were surveyed to capture demographics, healthcare utilization, and baseline health status. The primary outcome of interest was patient-reported routine place of healthcare. Other outcomes included frequency of ED visits in the previous 6 months, barriers to primary care and patient perception of health using select questions from the Medical Outcomes Study Short Form 36 (SF-36). RESULTS: Two hundred and ninety-two patients completed the survey of whom 58% were African-American and 44% were uninsured. African-Americans were equally likely to report 3 or more visits to the ED, but more likely to state a preference for the ED for their usual place of care (24% vs. 13%, p < 0.01). No significant differences between groups were found for barriers to primary care, including insurance. African-Americans less often reported comorbidities or hospitalization within the previous 6 months (23% vs. 34%, p = 0.04). On logistic regression modeling, African-Americans were more than 2 times as likely to select the ED as their usual place of healthcare (OR 2.24, 95% CI 1.22 - 4.08). CONCLUSION: African-Americans, independent of health insurance, are more likely than Caucasians to designate the ED as their routine place of healthcare.

Decreased lung function after preschool wheezing rhinovirus illnesses in children at risk to develop asthma.

BACKGROUND: Preschool rhinovirus (RV) wheezing illnesses predict an increased risk of childhood asthma; however, it is not clear how specific viral illnesses in early life relate to lung function later on in childhood. OBJECTIVE: To determine the relationship of virus-specific wheezing illnesses and lung function in a longitudinal cohort of children at risk for asthma. METHODS: Two hundred thirty-eight children were followed prospectively from birth to 8 years of age. Early life viral wheezing respiratory illnesses were assessed by using standard techniques, and lung function was assessed annually by using spirometry and impulse oscillometry. The relationships of these virus-specific wheezing illnesses and lung function were assessed by using mixed-effect linear regression. RESULTS: Children with RV wheezing illness demonstrated significantly decreased spirometry values, FEV(1) (P = .001), FEV(0.5) (P < .001), FEF(25-75) (P < .001), and also had abnormal impulse oscillometry measures--more negative reactance at 5 Hz (P < .001)--compared with those who did not wheeze with RV. Children who wheezed with respiratory syncytial virus or other viral illnesses did not have any significant differences in spirometric or impulse oscillometry indices when compared with children who did not. Children diagnosed with asthma at ages 6 or 8 years had significantly decreased FEF(25-75) (P = .05) compared with children without asthma. CONCLUSION: Among outpatient viral wheezing illnesses in early childhood, those caused by RV infections are the most significant predictors of decreased lung function up to age 8 years in a high-risk birth cohort. Whether low lung function is a cause and/or effect of RV wheezing illnesses is yet to be determined.

Multiple preoperative endoscopic interventions are associated with worse outcomes after laparoscopic Heller myotomy for achalasia.

BACKGROUND: The effect of preoperative pneumatic dilation or botulinum toxin injection on outcomes after laparoscopic Heller myotomy (LHM) for achalasia is unclear. We compared outcomes in patients with and without multiple preoperative endoscopic interventions. METHODS: This cohort study categorized achalasia patients undergoing first-time LHM by the number of preoperative endoscopic interventions: zero or one intervention vs. two or more interventions. Outcomes of interest included surgical failure (defined as the need for re-intervention), gastrointestinal symptoms, and health-related quality of life. Logistic regression modeling was performed to determine the independent effect of multiple preoperative endoscopic interventions on the likelihood of surgical failure. RESULTS: One hundred thirty-four patients were included; 88 (66%) had zero to one preoperative intervention, and 46 (34%) had multiple (more than one) interventions. The incidence of surgical failure was 7% in the zero to one intervention group and 28% in the more than one intervention group (p < 0.01). Greater improvements in gastrointestinal symptoms and health-related quality of life were seen in the zero to one intervention group. On logistic regression modeling, the likelihood of surgical failure was significantly higher in the more than one intervention group (odds ratio = 5.1, 95% confidence interval 1.6-15.8, p = 0.005). CONCLUSIONS: Multiple endoscopic treatments are associated with poorer outcomes and should be limited to achalasia patients who fail surgical therapy.

Fractional exhaled nitric oxide measurements are most closely associated with allergic sensitization in school-age children.

BACKGROUND: Factors affecting fractional exhaled nitric oxide (FeNO) in early childhood are incompletely understood. OBJECTIVE: To examine the relationships between FeNO and allergic sensitization, total IgE, atopic dermatitis, rhinitis, asthma, and lung function (spirometry) in children. METHODS: Children at high risk of asthma and other allergic diseases because of parental history were enrolled at birth and followed prospectively. FeNO was measured by an online technique at ages 6 and 8 years. Relationships among FeNO, various atopic characteristics, and asthma were evaluated. RESULTS: Reproducible FeNO measurements were obtained in 64% (135/210) of 6-year-old and 93% (180/194) of 8-year-old children. There was seasonal variability in FeNO. Children with aeroallergen sensitization at ages 6 and 8 years had increased levels of FeNO compared with those not sensitized (geometric mean; 6 years, 10.9 vs 6.7 parts per billion [ppb], P < .0001; 8 years, 14.6 vs 7.1 ppb, P < .0001). FeNO was higher in children with asthma than in those without asthma at 8 years but not 6 years of age (6 years, 9.2 vs 8.3 ppb, P = .48; 8 years, 11.5 vs 9.2 ppb, P = .03). At 8 years of age, this difference was no longer significant in a multivariate model that included aeroallergen sensitization (P = .33). There were no correlations between FeNO and spirometric indices at 6 or 8 years of age. CONCLUSION: These findings underscore the importance of evaluating allergen sensitization status when FeNO is used as a potential biomarker in the diagnosis and/or monitoring of atopic diseases, particularly asthma.

Rhodium-catalyzed asymmetric cyclodimerization of oxabenzonorbornadienes and azabenzonorbornadienes: scope and limitations.

Cationic rhodium(I)-catalyzed cyclodimerization of oxabenzonorbornadienes produced naphtho[1,2-b]furan ring systems in a single step with excellent yields and excellent enantioselectivities. The effect of various Rh(I) catalysts, Ag(I) salts, solvents, and phosphine ligands on the yield and enantioselectivity of the reaction was investigated, and the scope and limitations of this reaction with various oxabicyclic alkenes were studied. Similar results were obtained with the azabenzonorbornadiene analogues, providing the corresponding cyclodimerization products in excellent yields and excellent enantioselectivities.

Study on the reactivity of oxabicyclic alkenes in ruthenium-catalyzed [2+2] cycloadditions.

The ruthenium-catalyzed [2+2] cycloadditions of various bicyclic alkenes with an alkyne have been investigated. The presence of the oxygen in the bridgehead of the bicyclic alkene significantly enhanced the rate of the ruthenium-catalyzed [2+2] cycloadditions. The presence of a C1-substituent on the oxanorbornadiene decreased the rate of the cycloaddition and electron-withdrawing C1-substituents were found to be more reactive than electron-donating C1-substituents in the Ru-catalyzed [2+2] cycloaddition. The nature of the substituent on the benzene ring of oxabenzonorbornadienes showed little effect on the rate of the cycloaddition.

Ruthenium(II)-catalyzed cyclization of azabenzonorbornadienes with alkynes.

The ruthenium-catalyzed cyclization of azabenzonorbornadienes with alkynes leads to an unanticipated dihydrobenzoindole framework. Depending on the structure of the alkyne and the Ru catalyst, either a dihydrobenzoindole and/or a [2+2] cycloaddition product could be formed. Cp*Ru(COD)Cl was found to be an active catalyst for the cyclization of an azabenzonorbornadiene with a propargylic alcohol to produce the dihydrobenz[g]indole as a single regio and stereoisomer in good yield. For other alkynes, selective formation of the dihydrobenz[g]indole is possible by using a cationic Ru catalyst, [Cp*Ru(CH3CN)3]PF6.