When quickly assessing a patient for life threats, an EMR will check the patient's airway for any blockage. To find the answer to the question, we need to find a word that means "blockage" and has 5 letters.
One word that fits this description is "choke." The word "choke" means to have a blockage in the airway that obstructs breathing. So, "choke" is the 5-letter word that completes the sentence: "When quickly assessing a patient for life threats, an EMR will check the patient's airway for any blockage or 'choke'."