Respiratory rate refers to the number of breaths taken by a living being within a given time. It is usually measured and specified for a period of one minute. An adult human takes about twelve to 18 breaths in one minute. Proper respiratory rate is critical for optimal oxygen saturation of the blood.
What is respiratory rate?
Respiratory rate refers to the number of breaths taken by a living being within a given time. Respiratory rate indicates how many breaths are taken in a specified unit of time. Most often, the respiratory rate is given in breaths per minute. The respiratory rate is one of the vital signs. Especially in intensive care medicine in hospitals, its monitoring is considered important. The respiratory rate at rest, like the heart rate, varies from person to person and depends on various physical and psychological factors. However, there are normal values within which respiratory rates range. What breathing rate is considered normal depends on the age of the person in question: Infants breathe about 30-40 times per minute, children about 15-25 times and adults about 12-18 times.
Function and task
A person’s breathing rate can increase or calm down depending on the situation. For example, during sleep, a breathing rate that is slightly below normal is also considered adequate. Adjusting the breathing rate is necessary, for example, to allow more oxygen to enter the blood during periods of physical exertion. As a rule, the breathing rate is controlled subconsciously in the brain. To a certain extent, however, the breathing rate can also be influenced voluntarily. In addition to the breathing rate, the depth of breathing is also important for a person’s condition. If the breath is shallow, insufficient oxygen saturation can occur despite a normal frequency. However, as a rule, respiratory rate and depth are closely related and a disturbance of one parameter would also affect the other. Breathing rate is crucial for regulating the oxygen content in the blood and its balance with carbon dioxide saturation. During physical exertion, the body’s demand for oxygen increases. In this case, an increased breathing rate is actually healthy, because it is the only way to meet the increased demand for oxygen and carbon dioxide to be exhaled. Even in the case of reduced air pressure, for example when hiking at high altitude, the breathing frequency is automatically adjusted by the body. The frequency increases because lower air pressure means that less oxygen can be absorbed by the body. Taking in enough oxygen through the breath is crucial for supplying the organs in the body. In particular, vital organs such as the brain depend on a continuous supply of oxygen and can suffer severe damage after only a few minutes of insufficient supply.
Diseases and ailments
Changes in respiratory rate can have serious effects on the body’s oxygen supply. For this reason, respiratory rate and its related blood oxygen saturation must be closely monitored in critical care. Monitoring oxygen saturation is particularly necessary when the patient is being artificially ventilated. If the respiratory rate is too high, this is called tachypnea. In adults, tachypnea is said to occur when the respiratory rate is above 20. Closely related to tachypnea is hyperventilation. Often both occur together. In hyperventilation, too much carbon dioxide is exhaled, causing the concentration of the substance in the blood to drop. If the breathing rate is extremely high, it can happen that primarily the so-called dead space of the respiratory system is ventilated. However, this space is not involved in the exchange of gases between the lungs and the blood. As a result, the oxygen concentration in the blood drops. The state of insufficient oxygen saturation is called hypoxia. If hypoxia persists for too long, significant tissue damage can occur. Another phenomenon that often occurs along with tachypnea is dyspnea. This is the subjective feeling of shortness of breath. This sensation is caused by a lack of oxygen occurring despite a functioning respiratory system. On the other hand, if the respiratory rate is too low, this is called bradypnea. This refers to a condition in which an adult person takes fewer than 10 breaths per minute.A very low respiratory rate causes similar problems as too high a rate: The blood can no longer be sufficiently enriched with oxygen. As a result, the carbon dioxide level rises because the CO2 can no longer be sufficiently exhaled. If the CO2 level in the blood is significantly increased, this can lead to unconsciousness. The increase in bradypnea is apnea. This refers to the complete cessation of breathing. In this state, there is also a significant lack of oxygen in the body. Since even the vital organs, including the brain, can no longer be supplied with oxygen as a result, death can occur after just three to five minutes of respiratory arrest. One form of apnea is sleep apnea. Patients with this syndrome have breathing pauses of several seconds during sleep. However, because the body releases adrenaline during the resulting undersupply of oxygen to the brain, the patient audibly gasps for air after the cessation of breathing. However, he or she does not become awake. The consequences of apnea may include increased daytime sleepiness or cardiac arrhythmias.
