See-saw pattern in ventilator graphic: Is there any story behind?

Abstract

The importance of ventilator graphics cannot be over emphasized that provide the useful information about airway, ventilation, compliance and lung mechanics. Some bizarre forms of graphics are usually overlooked in view of artifacts, but sometimes these tracings may in fact predict some relevant information.

“Undulation on ventilator wave” may indicate serious lung pathology

“…[ 2 3 ] This sawtooth pattern or oscillation in ventilator waves and loops is usually considered as an indicator of secretion in airways. [ 1 4 ] During exhalation, the presence of secretion in the airway can generate cyclic increments and decrements in flow, secondary to transient obstruction of the airway lumen or the fluctuating movement of its content. [ 5 ] Extensive literature search did not reveal any association between this typical undulation and incomplete decompression of pneumothorax.…”