Forced oscillation technique in the detection of smoking-induced respiratory alterations: diagnostic accuracy and comparison with spirometry

Abstract

INTRODUCTION:Detection of smoking effects is of utmost importance in the prevention of cigarette‐induced chronic airway obstruction. The forced oscillation technique offers a simple and detailed approach to investigate the mechanical properties of the respiratory system. However, there have been no data concerning the use of the forced oscillation technique to evaluate respiratory mechanics in groups with different degrees of tobacco consumption.OBJECTIVES:(1) to evaluate the ability of the forced oscillation technique to detect smoking‐induced respiratory alterations, with special emphasis on early alterations; and (2) to compare the diagnostic accuracy of the forced oscillation technique and spirometric parameters.METHODS:One hundred and seventy subjects were divided into five groups according to the number of pack–years smoked: four groups of smokers classified as <20, 20–39, 40–59, and >60 pack–years and a control group. The four groups of smokers were compared with the control group using receiver operating characteristic (ROC) curves.RESULTS:The early adverse effects of smoking in the group with <20 pack–years were adequately detected by forced oscillation technique parameters. In this group, the comparisons of the ROC curves showed significantly better diagnostic accuracy (p<0.01) for forced oscillation technique parameters. On the other hand, in groups of 20–39, 40–59, and >60 pack–years, the diagnostic performance of the forced oscillation technique was similar to that observed with spirometry.CONCLUSIONS:This study revealed that forced oscillation technique parameters were able to detect early smoking‐induced respiratory involvement when pathologic changes are still potentially reversible. These findings support the use of the forced oscillation technique as a versatile clinical diagnostic tool in helping with chronic obstructive lung disease prevention, diagnosis, and treatment.

Tabagismo: o que tem sido abordado em periódicos brasileiros

“…Therefore, the authors recommend the use of this procedure in smokers undergoing surgery under general anesthesia. Faria et al 58 , comparing the use of forced oscillation technique (FOT) with spirometry to detect respiratory alterations induced by smoking in 170 smokers, showed that the FOT was more accurate than spirometry to assess the presence of potentially reversible early alterations, suggesting the use of this test as a complement to detect early airway changes, enabling better prevention efforts for the smoker.…”

Forced Oscillation Technique in the Detection of Smoking-Induced Respiratory Changes

“…The respiratory influence increases with the amplitude and frequency of the ventilation (irregular breathing or acute hyperventilation), introducing proportional reductions in the coherence function. A minimal coherence value of 0.9 is usually considered adequate (Mac Leod and Birch, 2001;Faria et al, 2010). Any time the coherence computed for any of the studied frequencies is smaller than this threshold, the maneuver may not be considered valid, and the examination needs to be repeated.…”

“…If this hypothesis is confirmed in a wider number of subjects, FOT may offer the possibility of demonstrating abnormalities during a phase at which pathological changes are still potentially reversible, helping to prevent the development of COPD. Continuing this research, Faria et al (2010) compared the diagnostic accuracy of the FOT and spirometric parameters in groups with different degrees of tobacco consumption. One hundred and seventy subjects were divided into five groups according to the number of pack-years smoked: four groups of smokers classified as <20, 20-39, 40-59, and >60 pack-years and a control group.…”

“…Another important advantage, particularly in pathophysiological research, is that FOT can be used to provide information on the mechanical characteristics of the respiratory system that is complementary to the information provided by spirometry Macleod and Birch, 2001;Oostveen et al, 2003;Bates et al, 2011;Kaczka and Dellacà 2011). This technique has the potential to greatly increase our knowledge regarding the pathophysiology of smoking, as well as to help in the clinical diagnosis of early smoking-induced respiratory alterations and COPD (Faria et al, 2009;Faria et al, 2010;Silva et al, 2011;Postma et al, 2012;Amaral et al, 2012).…”

Pesquisas em pneumologia recentemente publicadas em revistas brasileiras

“…The authors suggested discriminatory capacity, being a useful tool for the assessment of prognosis in pediatric patients admitted to tertiary pediatric ICUs. Faria et al (19) studied the use of the forced oscillation technique to investigate the mechanical properties of the respiratory system in order to detect early smoking-induced respiratory involvement, when pathologic changes are still potentially reversible. The authors concluded that the technique is a versatile clinical tool for the prevention, diagnosis, and treatment of COPD.…”