Dead Space (physiology) - Dead Space and The Ventilated Patient

Dead Space and The Ventilated Patient

The depth and frequency of our breathing is determined by chemoreceptors and the brainstem, as modified by a number of subjective sensations. When ventilated, the patient breathes at a rate and tidal volume that is dictated by the machine. Because of dead space, taking deep breaths more slowly (e.g. ten 500 ml breaths per minute) is more effective than taking shallow breaths quickly (e.g. twenty 250 ml breaths per minute). Although the amount of gas per minute is the same (5 L/min), a large proportion of the shallow breaths is dead space, and does not allow oxygen to get into the blood.