Approach to blunt chest injury Quiz: Ace Your Exams

A 43-year-old woman presents to the emergency department after being hit by a car while cycling. The patient was wearing a helmet. The driver of the car that hit her was pulling out of the driveway at 5 miles per hour and did not see the patient. She was hit on the left side and fell over to her right onto the pavement. The patient states she fell onto her right side, shoulder, and right chest. The primary survey is intact. The patient states that she has no difficulty breathing or shortness of breath and has mild pain in her right shoulder. Temperature is 36 °C (98 °F), heart rate is 82/min, blood pressure is 124/84 mmHg, respiratory rate is 14/min, and oxygen saturation is 91% on room air. Glasgow coma scale is 15. The pulse oximeter continues to show oxygen saturation of 91% on room air even after it is exchanged for another machine. The patient’s breathing continues to be unlabored without use of accessory muscles. She appears comfortable without new complaints. Radiographs of the right shoulder and arm are ordered. Secondary survey reveals mild scrapes and tenderness to palpation of the right shoulder and the right chest wall without ecchymoses. Labs are ordered and pending. Which of the following should be done next to help determine the cause of this patient’s hypoxia?