What is the difference between ventilation and respiration, and how they are measured?
Ventilation and respiration are two distinct processes related to breathing. Ventilation refers to air exchange in and out of the lungs and can be measured in various ways. Tidal volume represents the amount of air that moves in and out of the lungs during a regular breath and averages between 350 and 500 milliliters in adults. Minute volume, on the other hand, measures the total amount of air exchanged in one minute and typically ranges between five and eight liters. The respiratory rate indicates the number of breaths taken per minute, which is usually between 12 and 20, but can be higher in the elderly and those with chronic respiratory issues.
On the other hand, respiration involves the exchange of oxygen and carbon dioxide at the cellular level. This process is measured through parameters such as the fraction of inspired oxygen (FiO2) and positive end-expiratory pressure (PEEP). The FiO2 represents the amount of oxygen in the air being delivered to the patient, and 21% is the standard percentage in room air. However, this can be increased by using supplemental oxygen devices like a nasal cannula. PEEP, on the other hand, refers to the amount of air left in the lungs after exhaling, which prevents lung collapse and ensures there is always some airspace in the lungs. Understanding these differences is crucial for speech-language pathologists working with patients who may have respiratory issues or dysphagia, as breathing plays a vital role in various aspects of their treatment.
This Ask the Expert is an excerpt from the course, Breathe, Speak, Eat: What the SLP Needs to Know About Respiratory Failure, presented by George Barnes, MS, CCC-SLP.