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A 26 year female is brought into the emergency department by ambulance for acute exacerbation of her asthma. She has been hospitalized in the past for her asthma and once was intubated. On exam her temperature is 37.8 degrees, BP 110/60 HR 110/bpm and she is breathing at 28 breaths/minute. She is in moderate distress and unable to talk in full sentences. Diffuse expiratory wheezes are heard throughout the lungs. An ABG is taken. Which of the following values would most likely signal a need for intubation?
A. PCO2 21
B. PCO2 28
C. PH 7.39
D. PH 7.54
E. PO2 94
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fexofenadine!! u amaze me! how did u figure this one out! :O ;D
This patient is currently in respiratory alkalosis since she is in the middle of an asthma attack. In respiratory alkalosis, an ABG shows pH>7.40, pCO2
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This patient is currently in respiratory alkalosis since she is in the middle of an asthma attack. In respiratory alkalosis, an ABG shows pH>7.40, pCO2
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In respiratory alkalosis, an ABG shows pH>7.40, pCO2
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In respiratory alkalosis, an ABG shows pH>7.40, pCO2 less than40 and often an elevated pO2, due to the rapid breathing rate that blows off the CO2 (which is main acid in the blood). The work of breathing during an asthma attack is increased to overcome the constricted airways leading to an increase of lactic acid from the various muscles involved in breathing. Intubation is usually avoided in asthmatics, but cannot be avoided if the breathing muscles become tired out. This "tiring out" is seen on ABG when the pH begins to normalize because this "normal" pH is a sign that the patient is unable to blow off the CO2 and the lactic acid is building up. Therefore, although a pH of 7.39 (choice C) is considered "normal," during an asthma attack it is a ominous sign that the patient is going into respiratory failure.
