What to know about fasting before your lab test. With certain blood tests, you may be instructed to fast for up to eight hours before your appointment. Fasting before a blood draw means you donât eat or drink anything except water. Donât wait until the day of your blood draw to ask if you should fast. That could cause your appointment to be rescheduled.
Three described morphological types of emphysema. Centriacinar emphysema begins in the respiratory bronchioles and spreads peripherally. Also termed centrilobular emphysema, this form is associated with long-standing cigarette smoking and predominantly involves the upper half of the lungs. Panacinar emphysema destroys the entire alveolus uniformly and is predominant in the lower half of the lungs.
The major cause of hyperinflated lungs is COPD, or chronic obstructive pulmonary disease. It's a disorder that's actually made up of two critical components. One of these is emphysema, which refers to an irreversible enlargement of the air sacs of the lungs.