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

Abstract

Asthma scoring systems rely on physical examination findings. Point of care ultrasound may provide an objective means to document improvement in the work of breathing in paediatric lower airway obstruction. Thirty children with wheeze on physical examination (cases) and 15 children presenting with abdominal pain (controls) were studied. Using point-of-care ultrasound, m-mode tracing of lung was recorded above the right hemidiaphragm at the midclavicular line. Pleural line slope and excursion were measured before and after treatment. Twenty patients had a final slope measurement under 20°, and only three were admitted-one for hypoxia that resolved prior to ascending to the ward and another for poor compliance. Average decrease in pleural line slope after treatment was 43% and average decrease in pleural line excursion was 32%. Of the 10 children admitted, 8 had measurements over 25°. The correlation coefficient between pleural slope and pleural excursion was 0.67. All controls had a horizontal m-mode tracing at the pleural line. Oscillation of the m-mode line at the pleura is seen in children with lower airway obstruction and is absent in controls. There appears to be a correlation between beta-agonist therapy and decreased pleural line slope and excursion.