Rescuers are preparing to transfer a 52-year-old female with a mild pneumothorax to a larger hospital for further treatment. according to the physician arranging the transfer, he suspects her lung was punctured during a central line insertion two days ago. during transport a patient becomes unresponsive to painful stimuli and cyanosis is observed. rescuers rub her sternum with their knuckles and lightly brush her eyelashes with a finger tip. what do you suspect they are assessing?