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Also agree the narrowing of the lumen plus the pic is pointing towards Crohn's. The acute systemic sx of fever and chills is what made me go with diverticulitis (along with the hx of increasing constipation).
Why does the question say there is NARROWING OF THE LUMEN? Does that happen in diverticulitis? I went with Chron's at the last second against my better judgment because Chron's can cause strictures/narrowing of the lumen.
FA 2020 pg.383
Most common area for Diverticulosis to take place is the sigmoid colon and diverticulitis can cause obstruction (inflammatory stenosis). The key here is recognizing the risk factors (>60, chronic constipation) and signs of acute inflammation (fever, chills and LLQ pain).
I believe there would be no decrease in O2 saturation because oxygenated blood (high pressure) is shunted into deoxygenated circuit. As long as the lungs can keep up, this should increase venous oxygenation on average.
ty both of you for this, was wondering the same thing
O2 sat won’t change b/c you’re not adding deoxygenated blood to the arterial side. You’re just taking arterial blood and putting it into venous blood. Same reason why L->R cardiac shunts don’t decrease O2 sat (while in contrast, a R->L shunt would).
just realized: the high pressure of the arterial system keeps out low-pressure venous blood in an AV fistula (probably obvious to most ppl but it was a eureka moment for me lol)
ya you wont have decreased arterial O2 sat because oxygenation of blood is perfusion limited (FA19 --654) therefore oxygenation of the blood happens within the first .3seconds of entering the pulmonary capillary that you could even handle having more deoxygenated blood enter