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  #1  
Old 08-10-2012
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Lungs Blood Gas Interpretation Question!

A 56-year-old man with a 35-pack-year smoking history comes to the emergency department because of a 2-month history of fatigue, worsening non-productive cough, and shortness of breath. Physical examination shows jugular neck vein distention and pitting edema of the ankles and feet. Arterial blood gas results are shown.

pH 7.39 pCO2 53 mm Hg pO2 89 mm Hg HCO3 32 mmol/l SaO2 92%
Hemoglobin is 18 g/dL. Which of the following is the most likely diagnosis?

a) Infective endocarditis (IE)
b) Ischemia to the myocardium
c) Polycythemia
d) Pulmonary hypertension
e) Systemic hypertension
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  #2  
Old 08-10-2012
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Ee..Right HF
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Old 08-10-2012
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Looks like chronic hypoxemia leading to pulmonary HTN and ultimately to right heart failure so i will go with D
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Old 08-10-2012
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Quote:
Originally Posted by offpiste View Post
Looks like chronic hypoxemia leading to pulmonary HTN and ultimately to right heart failure so i will go with D

Pxt is not hypoxenic;SaO2 and PaO2 are within normal
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Quote:
Originally Posted by imgchuchu View Post
Pxt is not hypoxenic;SaO2 and PaO2 are within normal
1)well it looked that patient has chronic resp acidosis
2)SpO2 reading for a normal health non-smoker should be 95-99%. Smokers can be aroud 90-95% plus classic RHF signs and absence of LHF signs(non productive cough/orthopnea etc)lead me to think more towards pulmonary hTN
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Old 08-10-2012
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RHF is sure but what cause it is the main question. As others answered pulmonary HTN and systemic HTN. Then I will go with polycythemia ( as Hb is 18 , seems bit high to me) but plz don't ask patho physiology from me as certainly I don't know. Hehehe


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Old 08-11-2012
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Will go with D..
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Old 08-11-2012
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D
It looks chronic bronchitis to me with with resultant hypoxemia, apropriate polycythemia, hypercapnia, pulmonary hypertension and cor pulmonale
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Old 08-16-2012
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D
this guy has a compensated respiratory acidosis
Polycitemia is due to the body's adaptative mechanism with long term defects in oxygenation
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Old 08-16-2012
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IT D) Normal sao2 is > 95% chronic lung disease + RHF = Pulmonary Hypertension
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Old 08-16-2012
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Default D

i agree is D good analysis from medicalexaminer

It looks chronic bronchitis to me with with resultant hypoxemia, apropriate polycythemia, hypercapnia, pulmonary hypertension and cor pulmonale[/QUOTE]
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Old 08-16-2012
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the answer please ,still waiting answer for your other question
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Old 08-16-2012
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Quote:
Originally Posted by Kabutar111 View Post
the answer please ,still waiting answer for your other question
I'll try to post answers to at least some of the questions tomorrow
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  #14  
Old 08-16-2012
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D
CHRONIC BRONCHITIS DUE TO SMOKING -COMMON CAUSE OF RESPIRATORY ACIDOSIS (Pco2 >45mm hg) metabolic alkalosis is compensation(SERUM HCO3< OR=30MEG/L IN ACUTE RESPIRATORY ACIDOSIS,HCO3>30 MEG/L IN CHRONIC RESPIRATORY ACIDOSIS).RESPIRATORY ACIDOSIS IS MAIN CAUSE OF SECONDARY PH WHICH LEAD TO RIGHT HEART FAILURE -PROMINEMCE OF THE JUGULAR VEINS(INCREASED VENOUS HYDROSTATIC PRESSURE)DEPENDENT PITTING EDEMA
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Old 08-17-2012
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By the way patient has mixed disorder-because ph is normal, with chronic respiratory acidosis -PCO2 > 45 and HCO3>30 and metabolic alkalosis HCO3>28
using chronic respiratory acidosis formula expected HCO3=0.4 x(53-40)=5.2 expected HCO3=5.2+24=29.2 measured HCO3 is 32 which is higher than the expected compensation indicating the presence of additional metabolic alkalosis-more HCO3 than there should be for compensation
using the metabolic alkalosis formula ,expected PCO2 =0.7 x (32-24)=5.6 , 5.6+40=45.6 (43.6-47.6) the measured PCO2-53 is higher than it should be indicating the presence additional respiratory acidosis
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Old 08-17-2012
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Default correct answer

The answer is d) Pulmonary hypertension

This patient has pulmonary hypertension likely due to long-term smoking. Chronic obstructive lung diseases of any nature that involve both lungs will lead to scarring and obliteration of some of the vascular bed in the lungs. This leads to increased resistance. The right heart then has to pump blood against this increased resistance leading to its dilatation and hypertrophy. This condition is called cor pulmonale. Common symptoms are shortness of breath, fatigue, non-productive cough, angina pectoris, fainting or syncope, and peripheral edema.

smoking -> COPD -> increased pulmonary resistance -> cor pulmonale

pt has slightly increased pCO2 53 mm Hg and might be slightly hypoxic ->compensatory increase in EPO(but high Hb itself is not enough to diagnose polycythemia).

As for E - Systemic hypertension leads to changes in the left ventricle including left ventricular hypertrophy, and may eventually cause congestive heart failure and renal failure. The right side of the heart is not affected unless the hypertension is severe or remains untreated for a long period of time.
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Acid-Base-, Cardiovascular-, Pathology-, Respiratory-, Step-1-Questions

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