chapter 14 and abg instrument Flashcards
mixed venous sampling
sample drawn from the pulmonary artery catheter and also catheter measures the cardiac output
oxygen delivery
QT=cardiac output
do2=QT(Cao2)x10
oxygen uptake
vo2=QT(Cao2-Cvo2)x10
oxygen extraction ratio
O2ER=Cao2-Cvo2/CaO2
decreased cardiac output
increase in Ca-vo2
and cvo2,svo2,Pv02 are reduced
decreased oxygen artery content
increase cardiac output-all norm values
maintain ace of Ca-vo2-all reduced venous values
two valid statement of interpitation of mixed venous oxygenation
a low Svo2 indicates inadequate oxygen delivery
consequences of low Svo2
both Svo2 and Pvo2 will fall
Ca-vo2 increases
will normal Svo2 reflect normal ventilation?
no, because single organ system starvation may not reflect in mixed venous blood, also like cyanide poisoning and left-to right shunt
venous blood is more ________and shifts oxyhemoglobin to _______?
acidic,right
shunt equation
Qs/Qt=Cco2-Cao2/CcO2-Cvo2
electrode or half cell
the poles by which current enter and the leaves the cells
the point at which an electrochemical reaction occurs
an electrochemical cell consist of anode and cathode
ph glass
said to permeable to H+
calibration
Low cal 5% co2 0% o2 ph 7.384 buffer High cal 10 % co2 20% o2 ph 6.840 buffer
teflon is permeable to
co2 and other gases wont pass
