A22-year-old male was kicked in the abdomen several times. you find him lying on his left side with his knees drawn up. he is conscious and alert and complains of increased pain and nausea when he tries to straighten his legs. his blood pressure is 142/82 mm hg, his pulse rate is 110 beats/min and strong, and his respirations are 22 breaths/min and regular. in addition to administering high-flow oxygen, you should: