January 2014
Winter Bulletin Online Now
Our latest issue begins with a recap of AARC Congress 2013 and a short piece on our 2013 Specialty Practitioner of the Year, then follows with a Notes column from our chair-elect and two informative articles: one on methods of measurement for nasal nitric oxide and the other on the MGC Diagnostics plethysmography system. READ ISSUE
EBC May Be Useful in CF
Noting that the primary pathophysiology in cystic fibrosis consists of ion regulation and dehydration, researchers from the University of Arizona wondered whether exhaled breath condensate (EBC) collection could be used to detect differences in ion regulation between CF patients and healthy individuals and measure the effect of albuterol on EBC ions in these populations. They found out by measuring baseline EBC Cl(-), DLCO, and SpO2 in 16 patients with CF and 16 healthy controls. Results showed lower baseline levels of all three in the CF patients. Following albuterol, EBC Cl(-) increased in CF subjects, DLCO and membrane conductance remained unchanged, and pulmonary-capillary blood volume decreased in both groups, resulting in an improvement in diffusion at the alveolar-capillary unit and removal of the baseline difference in SpO2 by 90-minutes in CF subjects. “These results demonstrate that EBC detects differences in ion regulation between healthy and CF individuals, and that albuterol mediates increases in Cl(-) in CF, suggesting that the benefits of albuterol extend beyond simple bronchodilation,” write the authors. The study was published in the December edition of Clinical Medicine Insights: Circulatory, Respiratory and Pulmonary Medicine. READ ABSTRACT
Digit Ratio Predicts Lung Function
Could the ratio between the second to fourth digits predict lung function? South Korean investigators asked that question in a study involving 162 male and 83 female subjects between the ages of 34 and 90. Results showed:
- In males, univariate and multivariate analysis using linear regression models showed digit ratio was a significant predictive factor of FVC and FEV1.
- Among the 69 male ever-smokers in the study, FVC and FEV1 were correlated with smoking exposure rather than digit ratio.
- In the 83 female never-smokers, FEV1 and FEV1/FVC ratio were positively correlated with digit ratio on univariate analysis.
The investigators believe these findings show digit ratio is a predictor of airway function. The study was published in the Jan.-Feb. edition of the Asian Journal of Andrology. READ ABSTRACT
ISWT in Bronchiectasis
A new study out of Brazil that looked at the reliability, validity, and determinants of the incremental shuttle walk test (ISWT) in adults with non-cystic fibrosis bronchiectasis finds the test has a key role to play in assessing the condition. The study was conducted among 75 subjects who underwent cardiopulmonary exercise testing on one day and then two ISWTs 30 minutes apart on a different day. Steps taken per day in daily life were recorded as well. Among the findings:
- Distance walked was equivalent between the ISWT-1 (441±152 m) and ISWT-2 (445±153 m), with an excellent intraclass correlation coefficient.
- There were significant correlations between distance walked and peak load (r =0.82), VO2 (r =0.72), steps/day (r =0.61), and the Medical Research Council scale (r =-0.69).
- Age, body mass index, gender, FVC%predicted, dyspnea, and steps/day explained 70% of the variation in distance walked as expressed in meters and 60% when expressed as %predicted.
- Higher desaturation was observed during ISWT (-4±4%) than cycling (-2±3).
The study was published ahead of print by the Archives of Physical Medicine and Rehabilitation on Dec. 17. READ ABSTRACT
FENO Predicts Outcomes in Wheezy Infants and Toddlers
In an effort to determine the predictive value of fraction of exhaled nitric oxide (FENO) for persistence of wheezing, exacerbations, or lung function change over time in infants and toddlers with recurrent wheezing, Seattle Children’s Hospital investigators compared predictive values of single-breath FENO (SB-FENO ), tidal-breathing mixed expired FENO (tidal-FENO ), bronchodilator responsiveness, and the Castro-Rodriquez Asthma Predictive Index. Among the 44 children in the study, SB-FENO outperformed all of the other tests in predicting future exacerbations and persistence of wheezing at age three. SB-FENO and tidal-FENO were both associated with lung function decline over time. The study was published in the December edition of Clinical and Experimental Allergy. READ ABSTRACT
