Asthma attack - hypocapnea?

[crnc]

I have a question regarding asthma attacks. My teacher gave us this example:

patient in ER with acute asthma attack, gives VS, resp = 32. What type of blood gas would nurse expect initially? Answer: hypocapnea

I understand hyperventilating blows off CO2, but since asthma is causing restriction of airway, how does the CO2 get out?

[malenurse69, MSN, NP]

To my understanding its a restricted airway not a completely obstructed one, and hyperventilation will cause alveolar hypocapnea

[KatieMI, BSN, MSN, RN]

First, when there is no complete closure of small airways, patient will hyperventilate and blow CO2 out. If attack gets worse, normocapnia and then hypercapnia develops.

No wheezing with poor air movement ("silent chest") + NORMAL CO2 in asthmatic = get laringoscope ready. The guy better gets that tube down before he collects enough CO2 to get pH down for real.