General information
Breathing is an involuntary process that gets oxygen into, and carbon dioxide out of, your lungs. The air sacs in your lungs (the alveoli) are where the oxygen we breathe enters our blood. Breathing is controlled by your brain, which regulates the rate (how often), depth and rhythm of your breathing based on your body’s needs at the time.
When you exert yourself by getting up and out of a chair, putting groceries away, or going up a hill or flight of stairs, your muscles require more oxygen. Your body responds by changing how you breathe so that you can get extra oxygen to the muscle cells that are demanding it. For most people, taking a short break allows them to get their breathing under control.
Many people who live with chronic lung disease have poor gas exchange in the alveoli of their lungs, which causes low blood oxygen level. Depending on your lung disease and its severity, low oxygen levels can occur when you are active, at rest, and/or during sleep.
Your healthcare provider can assess your blood oxygen level by asking you to perform a walk test or sit-to-stand test during an office visit. Your blood oxygen level can be measured by an instrument called a pulse oximeter. An infrared light in the oximeter probe that is placed on your finger measures the blood oxygen saturation level, SPO2 (S= saturation, P=pulse, O2= oxygen). A blood test can also be used to measure blood oxygen level. This test is called an arterial blood gas (ABG). Pulse oximeter measures only oxygen saturation (SPO2) but ABG can measure blood level of both oxygen and carbon dioxide.
Not everyone who is short of breath has a low blood oxygen level. Oxygen therapy only benefits people with low blood oxygen levels. Proper assessment is the key.
When blood oxygen levels are low, oxygen therapy helps your lungs, heart and muscles work more comfortably and effectively. Oxygen therapy can improve:
- functional activity
- mood or stress level
- energy level
- concentration
More benefits of oxygen therapy include improved sleep, faster recovery from illness and fewer hospital admissions.
Oxygen prescriptions
Based on your disease severity and your needs, oxygen might be prescribed for you during specific times or continuously throughout the day and night. Your healthcare provider should assess your oxygen needs at rest and with exertion to determine if your oxygen needs. Chronic lung disease is treatable, but not curable. This means that as your disease progresses, your oxygen needs may change. It is very important to assess your blood oxygen level yearly, and to follow the oxygen delivery flow rates prescribed by your healthcare provider.
Oxygen prescriptions should be written to maintain a specific level of blood oxygen saturation, for example: oxygen setting of 2-4 lpm (liters per minute) to maintain oxygen saturation of greater than 90%.
Long-term oxygen therapy
Long-term oxygen therapy (LTOT) is oxygen therapy that is prescribed for at least 15 hours per day. LTOT increases survival and improves quality of life for people with COPD. It also improves quality of life for other lung diseases. LTOT can be delivered through different systems such as compressed oxygen gas cylinders, liquid oxygen or oxygen concentrators.
Compressed oxygen gas /liquid oxygen gas
Compressed oxygen gas /liquid oxygen gas offers non-stop oxygen flow while you inhale and exhale. It’s important to understand that when you get short of breath, for example when you exercise, your breaths become faster and shallower and you may not receive enough extra oxygen. This is why your healthcare provider may recommend that you increase your oxygen flow rate when exercising. Some people wonder why they need oxygen while they sleep – sometimes your blood oxygen level drops because of shallow breathing. Having a prescription for night time oxygen helps you feel better rested and clearer minded when you wake up. (This is different than sleep apnea)
Oxygen-conserving devices: Intermittent oxygen flow devices or pulsed-delivery devices
Special attachments or regulators can be used that deliver oxygen only when you inhale. These devices can deliver a big burst of oxygen when you first inhale then taper down until you exhale, or they can deliver a steady stream of oxygen only during the inhalation of your breath. These systems allow your oxygen delivery devices to last two to four times longer, which means that you can carry smaller devices. These devices are not for everyone. Your healthcare provider will know if this is the right device for you.
