Patients should have the following: A chest x-ray (eg, to assess for pneumonia, pleural effusion, pneumothorax, heart failure, or atelectasis) ECG (to assess for arrhythmia or ischemia) Arterial blood gases (ABGs), to confirm hypoxia and evaluate adequacy of ventilation Bedside echocardiography done by an intensivist may be used to assess for hemodynamically significant pericardial effusion or reduced global left ventricular or right ventricular function until formal echocardiography can be done.