Many Australians have some form of chronic obstructive pulmonary disease (COPD). COPD is a broad term that includes sufferers of emphysema, chronic bronchitis and chronic asthma or a combination of any of these three diseases. Chronic disease is a long-lasting condition that can be controlled but not cured.
Whilst each of the above conditions affects the body differently, often supplemental oxygen is prescribed to assist in the management of the condition and to improve the quality of life of a person.
How much oxygen do you give a COPD patient?
How oxygen gets into the body
As blood circulates throughout the body, the deoxygenated blood travels through the veins to the right side of the heart via the vena cava, and is pumped to the lungs where it is oxygenated.
It then returns back to the left side of the heart where the oxygenated blood leaves via the aorta (the largest artery in the body) to the brain and the remainder of the body. The deoxygenated blood returns to the heart via the veins, completing the cycle.
Arteries divide into smaller vessels called arterioles which connect to a much smaller and more extensive capillary network. It is at the capillary level that gases are exchanged. In an average adult with about 5.5 litres of blood, 70% is found in the veins with the remaining 30% distributed between the heart, arteries and capillary network.
Whilst blood itself is made up of several different types of cells, it is the role of the red blood cell to carry the oxygen to our tissues. The red blood cells make up approximately 35% of our blood. A red blood cell contains up to 250 million molecules of haemoglobin – an iron rich molecule. A single haemoglobin molecule can bind with (carry) up to four oxygen molecules.
As we breathe in, small vessels in our lungs carry the oxygen to the tissues and as we breathe out, carry Carbon Dioxide (CO2) out of the body. CO2 is a waste product of metabolism – the physical and chemical processes that occur within a living cell or organism that are necessary for the maintenance of life. Any imbalance in this process can lead to a number of serious health risks.
If a person inhales too much oxygen and is unable to exhale the carbon dioxide it can lead to a condition called hypercapnia.
The answer to the question of whether a person can overdose on Oxygen is….Yes!
To read more on Hypercapnia click here
Expert Pulmonologist describe oxygen therapy for COPD and the benefits and circumstances in which it may be required.
What is oxygen therapy for COPD?
It's really important that we separate out when someone who has a low oxygen in their blood by the pulse oximeter reading or by the blood gas, versus someone who's just short of breath because a patient can be really short of breath and have normal oxygen and I've had patients that have come to me that aren't that short of breath, but their oxygen is low. So that's why we need to measure the test. Patients with FEV 1s (forced vital capacity) less than around fifty to forty percent really should have it measured at every single visit. I personally measure the oxygen saturation at every visit in all of my patients but I think it's very important with those with more severe lung disease.
Now once the oxygen level is low and a little bit different in different patients depending on what other diseases they have but certainly when it's eighty eight, eighty seven percent, even eighty nine percent in some patients, when they're just sitting resting that person needs to wear the oxygen twenty four hours a day seven days a week. Now it's really hard for them to wear that all the time. So really the cut off number is sixteen hours a day, if they'll wear it at least sixteen hours a day, every single day then that reduces their chance of dying from COPD, like drastically.
Is the benefit of using supplemental oxygen, can reduce mortality for patients suffering from severe lung disease?
Absolutely and it's the number one thing that we have that reduces mortality, we know other things reduce mortality as well but oxygen is probably the biggest bang for the buck in patients with resting hypoxia, meaning they're just sitting down. Now in those that have normal oxygen at rest but then they are able to walk and their oxygen goes down, right now we give them oxygen and we think that it's probably helpful and there's a large study that's going on right now to really see the benefit of using medical oxygen.
What kind of Oxygen Concentrators available for people suffering with COPD?
There are a lots of different types of oxygen devices available most are given through the little nasal cannulas that you see patients walking around with, there are portable oxygen that they can walk around with, some roll and are heavier, some are a liquid and they actually can carry them like on a little backpack, then usually around the house there’s a also a thing called a home concentrator, that plugs into the wall and they have a long cord that they can walk around their house with a long tube so that they can wear their oxygen.
I had a patient the other day, and told me, you know they gave me this big oxygen cylinders that I need to carry around when I go anywhere and she saw another person who had it is small oxygen device, that doesn’t need any cylinders, they just plug that means a battery just needs to be charged. What other devices, what do we have now that are readily available?
We have available medical oxygen in the market called “portable concentrators” rather than the big bulky machines they can plug in either to the wall or to the cigarette lighter in the car, things like that and they actually produce the oxygen there, so you don’t have to have the big cylinders, the big thing is cost and so different plans cover different machines and devices and so it’s really important to figure out… so your patients not paying out of pocket what devices their insurance company covers.
Is it Possible to bring the medical oxygen when travelling overseas?
Definitely! just need to arrange the oxygen ahead of time, they’re not allowed to take the machine with them on the plane, so they can have it up until they get in the airport in the in the airport the airlines will arrange ahead of time to have the oxygen there, they can arrange to have the oxygen on the plane and then they need to have the oxygen company deliver some oxygen to them when they land. So it can be done it just takes some planning,
By: Sandra G. Adams, MD
Professor of Medicine
Division of Pulmonary Diseases and Critical Care Medicine
University of Texas Health Science Center at San Antonio and South Texas Veterans Health Care System