Medical Surgical Asthma #6


While caring for a client with asthma, the nurse receives the client’s arterial blood gases back from the lab which reveals a PaCO2 of 47 and a pH of 7.0. Which action by the nurse is best?


  1. Report STAT, prepare for possible mechanical ventilation.
    • Rationale:

      This answer is correct because this lab indicates respiratory acidosis. Respiratory acidosis signals imminent respiratory failure and should be reported immediately. Mechanical ventilation may be necessary for the client with respiratory acidosis.

  2. Continuous monitoring of ABGs.
    • Rationale:

      This answer is not correct because although continuous monitoring of ABGs is necessary, an intervention is required at this time. Taking action to achieve homeostasis to prevent respiratory failure for this client is the nurse’s best action.

  3. Encourage coughing and deep breathing.
    • Rationale:

      This answer is not correct because although coughing and deep breathing help the lungs facilitate removal of CO2, the client is in acute respiratory acidosis, which can be fatal. The nurse’s best action is to report the lab findings immediately and prepare for mechanical ventilatory support.

  4. Hold respiratory depression drugs.
    • Rationale:

      This answer is not correct although respiratory medications depress the respiratory drive, the client is in acute respiratory acidosis which is a medical emergency. An immediate intervention to prevent respiratory failure is indicated at this time.


Monitoring of ABGs is imperative with the client admitted into the hospital for an asthma attack. During an asthmatic attack, clients may develop respiratory alkalosis. A more ominous finding is acute respiratory acidosis, which indicates respiratory failure is imminent and is considered a medical emergency.


Learning Outcomes

Respiratory acidosis occurs when the lungs ability to remove CO2 is impaired and the kidneys excrete acids through the urine to compensate. Respiratory acidosis is a medical emergency and needs to be addressed swiftly. When a client breathes too slowly, CO2 buildup in the lungs occurs. COPD and emphysema, damage the alveoli where gas exchange happens. Anything that causes the diaphragm to weaken, such as a neuromuscular disease, the body cannot adequately expel carbon dioxide. In the case of asthma, the bronchial tubes constrict during bronchospasm which results in decreased gas exchange. Immediate intervention is indicated and mechanical ventilation may be required.

Test Taking Tip

Have comprehension of acid-base balance and memorize the following values: pH 7.35-7.45, PaCO2 35-45, and HCO3 22-26.

Video Rationale