ARDS and aerosol delivery

Q: All of the following are the effects of prone positioning in Acute Respiratory Distress Syndrome (ARDS) except? 

A)  Improved configuration between lung and thorax 
B) Less abdominal pressure 
C) Improved secretion mobilization 
D) Decreased aerosol delivery
E) More homogeneous perfusion 


Answer: D

Although prone positioning is around for a while it tool few decades to understand the physiologic effects and a proper way to operate it. Recently, this results in evidence-based literature leaning towards its application in severe ARDS particularly prior to application of extracorporeal membrane oxygenation (ECMO). All of the above are the effects of prone position except D as prone position increase/improve the aerosol delivery due to reopening of the more alveoli.


Reference:

Oczenski W, Hörmann C, Keller C, et al. Recruitment maneuvers during prone positioning in patients with acute respiratory distress syndrome. Crit Care Med 2005; 33:54.