Picture yourself on a call with a patient who had hip surgery a week ago and today suddenly felt short of breath. Her oxygen saturation is 82% on room air so you place a non-rebreather (NRB) mask on the patient and turn the flowmeter to 15 LPM, enough to keep the bag no more than 1/3 depleted. Her breath sounds are clear with good aeration to both bases. There is no tracheal deviation; chest rise is symmetrical and the patient is breathing at a rate of 18-20 bpm. The oxygen saturation creeps up to 90%. You are an hour from your final destination with heavy traffic ahead.
Given this scenario, have you ever asked yourself: “Do I have enough oxygen to complete this mission?” You started your shift with 1,100 psi in your on-board tank and had a portable tank with 1,500 psi. You used oxygen on two earlier runs, both nasal cannula patients, one running at four and the other at six LPM. Both runs were just under an hour. Can you accurately determine how much time and oxygen you have in the ambulance for your hypoxic patient? You should. In fact, this calculation is an EMT level competency.