You are called to a nursing home for an 85-year-old patient complaining of abdominal pain. the patient has a history of dementia and cannot describe the pain to you. the nurse states the patient has been vomiting dark coffee ground emesis for about an hour. his blood pressure is 90/40, pulse 100, and respiratory rate of 24. why should the emt use an oxygen mask with caution?

According to the history and physical examination of the patient, the patient may have a upper gastrointestinal bleed most probably from a bleeding peptic ulcer. A bleeding peptic ulcer can cause abdominal pain and vomiting described as coffee ground vomit because of the reaction of the blood with the stomach acids. The patient's vital signs signify that the patient is in the state of hypovolemic shock. The emergency medicine consultant should use an oxygen mask with caution because additional vomiting episodes may recur and if the patient is wearing an oxygen mask, the vomit cannot be cleared thoroughly and may even cause aspiration.