February 2014
Webcast Central: Your Ticket to CRCE
One of the best ways to earn the continuing education
credits you need to maintain your license to practice
is to attend the AARC Webcasts that take place every
month throughout the year. These “virtual”
sessions only last about an hour, making them a
quick way to pick up credits one at a time. Sign
up for the live versions and your CRCE is free,
but you can also take advantage of archived sessions
and earn CRCE for the new low price of just $7.50
each for members. LEARN
MORE
Common PFTs Make a Difference
A new study out of Belgium finds four common pulmonary function tests — spirometry, lung volume, airway resistance, and diffusing capacity — add valuable knowledge to the diagnosis of patients with respiratory conditions of an unknown nature. The investigators analyzed 979 patients in a prospective study to determine the role each test played in helping clinicians determine differential diagnoses and arrive at a definitive diagnosis. The utility of the tests was examined via focus groups who were presented with clinical history and pulmonary function data. The final diagnosis was established by the attending physician. Results showed a progressive reduction in the number of differential diagnoses with the use of each additional pulmonary function test, along with an increase in the accuracy of the final diagnosis. “Each of the four classic pulmonary function tests contributes significantly and independently to the final diagnosis in new patients with respiratory symptoms seen by pulmonologists,” write the authors. “Thus, funding of these tests is justified in that setting.” The study was published in the November edition of The Lancet: Respiratory Medicine. READ ABSTRACT
Excessive Dynamic Airway Collapse: Any Impact on Dynamic PFTs?
Researchers from Norway used a garden hose to explore the flow resistance created by excessive dynamic airway collapse (EDAC) and how it relates to pulmonary function tests, then observed the tracheal obstruction during forced expiration and cough in 104 stable COPD patients, with the cross-sectional area reduction estimated from results gleaned from the garden hose study. In the garden hose study, the flow resistance increased significantly when the cross-sectional area was reduced to >70% for an obstruction length of 3 cm. In the patient study, 18 subjects were found to have EDAC during cough, but none during forced expiration, and no correlation was seen between the obstructions and PFT results. The researchers conclude, “EDAC during peak pressure has negligible impact on pulmonary function tests and breathing symptoms.” They published their findings in the January edition of the Journal of Bronchology & Interventional Pulmonology. READ ABSTRACT
FeNO as an Inflammatory Biomarker
In an effort to better understand the clinical significance of fractional exhaled nitric oxide (FeNO) as an inflammatory biomarker, Johns Hopkins investigators publishing ahead of print in Lung on Jan. 12 looked at 16 children ages 13-15 with a significant elevation in FeNO of ≥80 parts per billion (ppb) at baseline. These children were compared to 24 children of similar ages with a moderate FeNO elevation (40-79 ppb) and 53 with normal-to-low FeNO (<40 ppb) levels. After a year and a half of follow up, the investigators found:
- Mean FeNO levels were 82.6 ppb for atopic asthmatics, 50.6 ppb for nonasthmatic atopics, 17.0 ppb for nonatopic asthmatics, and 17.8 ppb for nonatopic nonasthmatics.
- FeNO levels remained stable: 63% of the high FeNO group had a FeNO ≥80 across all four measurements and 87% of the normal-to-low FeNO group had a FeNO of <40 across all four measurements.
- The high FeNO group was found to have an elevation in IL-5, IL-6, IL-10, and total serum IgE after adjustment by age, sex, height, body mass index, and atopy and asthma status.
The authors believe these results show elevated FeNO is an indication of an atopic phenotype regardless of asthma diagnosis, clinical symptoms, or corticosteroid use, and is also associated with a systemic elevation in inflammatory cytokines. READ ABSTRACT
Bariatric Surgery Improves Pulmonary Function
Bariatric surgery can have positive effects on pulmonary function over the long term, report researchers from Norway who performed spirometry in 113 patients at baseline and then again five years after their surgery. Overall, men in the study had reduced their weight an average of 24% by five years and women had reduced theirs by 31%. FEV1 increased 4.1% in women and 6.7% in men; FVC went up by 5.8% and 7.6%, respectively. Despite an expected decline in pulmonary function due to age, by the five year follow-up, FEV1 had increased 36% of the difference towards the estimated normal FEV1, and FVC had increased a corresponding 70%. Forty-eight percent of the subjects with asthma, and 80% of those with obstructive sleep apnea, were symptom free at five years. The study was published ahead of print by Obesity Surgery on Jan. 18. READ ABSTRACT
