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  #1  
Old 03-24-2012
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Question Analyze this ABG

A 69-year-old woman is brought by ambulance to the emergency department from a skilled nursing facility complaining of breathing difficulty. The patient suffered a hemorrhagic stroke and subsequent left hemiplegia, dysarthria, and dysphagia 6 months ago. One hour ago, her nurse observed her vomiting and probably aspirating an unknown amount of the vomitus. The patient is in apparent respiratory distress with rapid breathing, an expiratory wheeze, and a cough with pink frothy sputum. Vital signs are temperature, 101.2F; blood pressure (BP), 135/85 mm Hg: heart rate (HR), 115 beats/min; respiration rate (RR), 24 breaths/min. Chest examination shows wet inspiratory and expiratory crackles bilaterally. Chest x-ray (CXR) shows bilateral, predominantly lower lobe alveolar infiltrates.

A. pH 7.40; PaO2 80; PaCO2 50
B. pH 7.21; PaO2 75; PaCO2 20
C. pH 7.30; PaO2 80; PaCO2 30
D. pH 7.43; PaO2 50; PaCO2 40
E. pH 7.30; PaO2 60; PaCO2 100
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  #2  
Old 03-25-2012
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ans.C, bcoz this pt has pulm infection look temp and resp rate, inc RR leads to dec CO2, this pt has expiratory wheeze its may be due to any obstructive lung dis e.g COPD or emphysema, but pt is non smoker, due to acute resp alkalosis there compensatory metabolic acidosis.
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  #3  
Old 03-25-2012
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Quote:
Originally Posted by usmlepak View Post
ans.C, bcoz this pt has pulm infection look temp and resp rate, inc RR leads to dec CO2, this pt has expiratory wheeze its may be due to any obstructive lung dis e.g COPD or emphysema, but pt is non smoker, due to acute resp alkalosis there compensatory metabolic acidosis.
i also did c. its wrong.
qbank mentions..
The clinical picture is consistent with aspiration pneumonia. A common finding in aspiration pneumonia is marked hypoxemia... comments?
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  #4  
Old 03-25-2012
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I think it should be D) pH 7.43; PaO2 50; PaCO2 40..

This patient looks to me like a classic case of adult respiratory distress syndrome secondary to aspiration pneumonia. The patient has pink frothy sputum which means that she is having pulmonary edema. Note that there is no cardiac abnormalities to explain the pulm edema, further re-enforcing the fact that it is secondary to aspiration pneumonia in this case.

ARDS characteristically presents with hypoxemia with a normal or increased pCO2.
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Old 03-26-2012
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as it is clear that he is having pulmonary edema
also we know there is no proper gas exchange between blood and alveoli (as there is fluid in interstitium) so o2 falls ..co2 builds up(no effect of ventilation here)...and acidosis
because of metabolic compensation ph returns to normal
so over all i will go for A

I THINK SO,,,,,,,,,,
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Acid-Base-, Internal-Medicine-, Pulmonology-, Step-2-Questions

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