A client is transferred to the hospital unit as a direct admit. While the nurse is obtaining part of the admission history, the client suddenly becomes semiconscious. Assessment reveals a systolic BP of 70 mmHg, heart rate of 130 beats/min, and respiratory rate of 24 breaths/min. The nurse suspects a leaking or ruptured abdominal aortic aneurysm. What is the nurse's best initial action?