sridevibandaru24
Forum Guru
Topics: 33
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You are called to see a 67-year-old woman with severe COPD who was intubated on the medicine floor 30 minutes earlier because of respiratory distress. Her temperature is 37.0 C (98.6 F), blood pressure is 90/60 mm Hg, pulse is 133/min and regular, and respiratory rate is 24/min. Her ABG reveals the following: pH 7.21, PaCO2 80 mm Hg, PaO2 69 mm Hg, and her oxygen saturation is 91%. Her current ventilator settings are assist control (AC), respiratory rate (RR) of 12/min, tidal volume (TV) of 500 ml, fraction of inspired oxygen (FiO2) is 50%, positive end expiratory pressures (PEEP) of 5 mm/Hg. The most appropriate intervention at this time is to
A. decrease set respiratory rate
B. increase the fraction of inspired oxygen
C. increase PEEP
D. increase tidal volume
E. make no adjustments at this time
please explain this Q...
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| jedw
Forum Newbie
Topics: 0
Posts: 13
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There's a lot of info in this question, but you shouldn't be worried.. Notice that she has respiratory acidosis due to COPD..
In COPD there's a VENTILATION problem leading to an increase in PaCO2, which is connected to the lowering of PaO2 - increasing FiO2 leads to an incraese in PaO2 thus lowering PaCO2 and increasing pH..
by the way remember that giving 100% O2 is a proper therapy in COPD
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| nirvanamona
Forum Senior
Topics: 6
Posts: 28
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forgive me if i'm wrong but i thought that in managing a patient with an established diagnosis of COPD we shud be careful not to eliminate the only drive that keeps these patients going..i.e. the O2 drive....increasing the FiO2 is gonna be disastrous!
regarding the answer...i'd rather stick with the current settings ...e?
don't know bout PEEP...
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| nirvanamona
Forum Senior
Topics: 6
Posts: 28
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GOSH i completely forgot the fact that the patient was INTUBATED! silly me...anyway jedw...u explained it well ....will go for B i guess.....
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| icemaiden
Forum Elite
Topics: 9
Posts: 117
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one doubt----if u need to decrease PaCO2----incresing PaO2 isnt the solution is it? PaO2 depends on Paco2 but not the vice versa. PaCO2 can be decresed by incresing the alveolar ventilattion---which here would be D)i,e increasing the tidalvolume.By this the Paco2 would decrese and this could then increse the PaO2.
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| PatriciaLim
Forum Senior
Topics: 13
Posts: 54
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COPD patient generally has high Pco2, and low sats.
this patient's sats is 91% which might be normal for him considering that he has COPD.
his resp rate is stable and tidal volume is 500ml? aint tat a normal reading?
An aim of maintaining Po2 above 8kpa is necessary for COPD patient in a clinical setting. His Po2 is 69mmHG ( normal is 75-100 mmhg). Tat aint that low for a copd patient ?
my ref is clinical handbook of medicine (oxford).
All and all i think the pt is stable and my guess is E.
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| MRMAVERICK
Forum Guru
Topics: 41
Posts: 722
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Y NOT INCREASE TIDAL VOL-AS INCREASING FIO2 WILL NT AFFECT PCO2 OR PH
RATHER IT IS GOIN TO REMOVE DRIVE FOR VENTILATION-INCREASIND TIDAL VOL WILL INCREASE MINUTE VENT AND INCREASE WASHOUT OF CO2
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| muzammil
Forum Guru
Topics: 16
Posts: 657
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well i think curetnsetting are fine but if there is gona be any alteration it wud be tidal volume
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| sridevibandaru24
Forum Guru
Topics: 33
Posts: 434
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the answer is increasing tidal volume which increases the minute ventilation
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| proctalgia
Forum Senior
Topics: 2
Posts: 209
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The basic problem appears to be high pH and elevated PaCO2.
So to my mind, the answer is to increase alveolar ventilation to get rid of CO2.
What do you guys think about answer D?
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| new_n_lost
Politically InCorrect
Topics: 653
Posts: 6,074
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Guys here is my 2 cents on the question
THe pt is on a VENTILATOR n has COPD right . In COPD the main problem is getting CO2 out of Lungs. Right if we inc the Tidal Volume that would lead to BAro trauma as Emphysema is also present. In Such Pt. the ideal therapy is maintain the Adequate Lung perfusion with high Flow Values so if Inc the FiO2 then we will be helping the Pt.
the ans is B
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| MD_toronto
Forum Junior
Topics: 2
Posts: 27
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here is my explaination..
This person has COPD for a while...so this is case of chronic hypoventilation which means that her central chemoreceptors are adapted and can't control level of carbon dioxide. Therefore, only peripheral chemoreceptors(which depends On Po2 level) will drive her respiration which is active during low P02.
Now, increasing O2 fraction will worsen her condition which will increase P02 level.
I would say increasing tidal volume would be better choice.
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| new_n_lost
Politically InCorrect
Topics: 653
Posts: 6,074
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here is a link guys which supports the USE ofassist control in COPD pts. in Assist Control the Tidal Volume is Fixed n Oxygen Delivery is variable in all the scenarios n the classical approach is to have a FiO2 of 60-65% thus in case we can increase the FiO2
here is the link which led me to this conclusion PLZ CORRECT ME IF I M WRONG
http://www.emedicine.com/med/topic2011.htm
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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