Vertical displacement of pleura: a new method for bronchospasm evaluation?

Abstract

Background: Lung ultrasonography has been increasingly recognized has a valuable diagnostic tool. In adult patients with asthma/chronic obstructive pulmonary disease and wheezing, LUS usually presents as an A/nude profile (normal profile, with sliding and A-lines, and without any abnormal findings) or at most reveals a decrease/absence of lung sliding. Therefore, until now simple point-of-care ultrasonography appeared to be unable to assess the severity of airflow limitation. Case presentation: We report the case of a woman presenting to the emergency department with an asthma exacerbation. Bedside ultrasound showed the usual A/normal profile, but also an associated vertical pleural displacement, probably secondary to hyperinflation and accessory muscle recruitment. We evaluated the described movement with M-mode and established a comparison index between end-inspiration and end-expiration, using the skin as reference. This index showed improvement and complete normalization during treatment. Conclusions: Pleural vertical displacement appears to be a sonographic alteration associated to bronchospasm and accessory muscle recruitment. It is easily identifiable and measurable on LUS, thus possibly representing a new method to evaluate bronchospasm and monitoring treatment response. Further research is needed to confirm or refute this finding.

Pleural line slope in point of care ultrasound assessment of paediatric wheeze may reflect respiratory effort

“…They suggest that this vertical displacement of the pleural line relates to hyperinflation and accessory muscle use and may be useful in monitoring asthma therapy. 22 To our knowledge, the POCUS application described in our study is novel. Our technique should be simple enough for use by a paediatric resident or general paediatrician without advanced POCUS skills, should allow for an objective measure of respiratory effort and may be quicker and more accurate than the scores used to assess severity of lower airway obstruction in paediatric acute care.…”

“…They describe the pleural line presenting as an undulating wave that reverts with beta‐agonist therapy to a flat line and suggests an index that relates the distance between peak and trough of the pleural line and skin surface. They suggest that this vertical displacement of the pleural line relates to hyperinflation and accessory muscle use and may be useful in monitoring asthma therapy 22 …”

Determinants of point-of-care ultrasound lung sliding amplitude in mechanically ventilated patients

“…Pulmonary pathologies affecting ventilation, such as bacterial pneumonia, tuberculosis or a history of prior pleurodesis are also likely to affect regional lung sliding amplitude. Interestingly, vertical displacement of the pleural line has been shown to correlate with airflow limitation in patients with bronchospasm and could serve to complement horizontal lung sliding amplitude in patients with obstructive lung disease [ 16 ]. In light of our growing understanding of its applications, POCUS guided assessment of regional ventilation may represent an untapped well of information in critically ill patients.…”

Lung ultrasound in a nutshell. Lines, signs, some applications, and misconceptions from a radiologist’s point of view. Part 2

“…Importantly, lung sliding may be abolished in asthma exacerbation, so care must be taken not to confuse it with pneumothorax, in which also lung point should be present [ 61 ]. An interesting case was published in which vertical displacement of pleura was proposed as method of bronchospasm evaluation [ 62 ]. It seems to be associated with accessory muscle recruitment or even bronchospasm, but larger studies are necessary to confirm the feature.…”