to snoo-finity ... and beyond!
to snoo-finity ... and beyond!
I personally thought of this questions thinking of it in these terms.. Since the patient has a mass in the trachea peak expiratory and inspiratory flow will be interrupted, and would therefore be decreased. FVC1 would also have to decrease by this. This eliminated all the other choices.
I overthought this one big time. Since the question said the mass was pressing on the outside of the trachea, I figured that during inspiration, b/c the chest expands, so more space, so the mass would have less effect on the trachea as the chest expands (and conversely, it'd have more of an effect during expiration as the chest wall retracts). Apparently, it was just straight up blockage and I thought waaay to hard. Oops.
Like any of the COPD, the patient has a difficult time exhaling the inspired air (thus its called an obstructive disease)
COPD results in FVC decrease, FEV1/FVC ratio decrease, FRC increase, and peek expiatory flow decrease.
A tumor or any other object that would compress on or narrow these the air way tract would present as a COPD.
Inhaling and exhaling would be limited
It could be that this is a fixed upper airway obstruction, which would prevent inflation and deflation of the airways due to the tumor clamping down on the trachea.
I figured this was a variable intrathoracic obstruction and got it wrong.
According to UpToDate, INTRAluminal tracheal obstruction is varaible, while EXTRAluminal tracheal obstruction (like in this case) is fixed.
Hi guys can someone please elaborate on these findings. I understand she has lung cancer that's impeding her trachea. But how is this representative of an obstructive disorder? Aren't lung cancers restrictive if anything? Thanks
submitted by nwinkelmann(154), 2019-07-07T23:32:39Z
@gh889 "Because the obstruction is above the alveolar regions there is a decrease in air flow, not lung volumes, which would make this an obstructive pathology" is the most helpful explanation. If you know the most basic definition/pathophysiology of obstructive vs restrictive (which I do, just didn't in that most simplified way), then you can figure anything out. If something is impacting airway flow = obstructive, if something is impacting airway volume = restrictive. THANK YOU!