5) Answer

C. Arterial blood gas

Rationale

•ABG levels should be assessed prior to any ventilation changes to establish a baseline. ABG levels are often ordered 1 hour after the changes to assess for improvement.

•Breath sounds and FiO2 requirements are important data, but do not neccesarily dictate ventilator settings or weaning.

•An echocardiogram does not help in the assessment of a patient’s respiratory status.