Bradypnea indicates a respiratory rate of less than 12 breaths per minute. It is an abnormally slow breathing rate, whereas the average respiratory rate for a resting adult is about 12-15 breaths per minute, and this rate changes from infancy through adolescence.
The student asked which of the following indicates bradypnea: 1) Less than 12 breaths per minute, 2) Less than 18 breaths per minute, 3) More than 20 breaths per minute, 4) More than 25 breaths per minute. Bradypnea is defined as an abnormally slow respiratory rate, and typically, the average respiratory rate for a human is about 12-15 breaths per minute under restful conditions. Therefore, the correct answer is option 1) Less than 12 breaths per minute.
It's important to note the normal respiratory rate varies with age. For a child under 1 year of age, a normal respiratory rate is between 30 and 60 breaths per minute. As children grow, the rate decreases, and by the time they reach about 10 years old, the normal respiratory rate is closer to 18 to 30 breaths per minute. By adolescence, it becomes similar to that of adults, which is 12 to 18 breaths per minute. Moreover, the regulatory mechanism for breathing is controlled by the respiratory center within the brain, responding to carbon dioxide, oxygen, and pH level changes in the blood.