Having documented a significant, but relatively slow decline in my lung function over the past decade, Ive often wondered what life must be like for other asthmatics who have a baseline FEV1 below 25%. Well, now I know.
According to the last spirometry results, which I did for my annual SARP follow up visit last week, my baseline FEV1 is now down to 23%. We’re talking less than 1/4 of normal. Equally troubling is that my FVC has taken a hit as well, at only 39%, which is why my FEV1/FVC ratio is still in the “moderate severe” range instead of the “very severe” range. From a purely asthma standpoint that doesn’t leave a lot of reserve for the lungs to handle an acute flare up. Even the mildest exacerbation can be life threatening and throwing a respiratory infection in the mix, would pretty much guarantee the end. Lucky for me, I still have a little bit of airway responsiveness left. During this last test my FEV1 actually increased to 31% after 6 puffs of Albuterol. The problem is that my FEV1 drops back down into the 20’s again after just an hour or two. Im on daily prednisone and have Ive tried every long acting bronchodilator out there, but nothing keeps my numbers up for very long. Needless to say, it ultra important for me to do whatever it takes to prevent flare ups from getting out of control.
Getting back to that original question of what it feels like to live with numbers like this, personally Im not really noticing a huge difference while at rest, but I can sure tell a difference when I exert myself too much. Walking on even the slightest incline for example, is twice as difficult for me now as it was just a year ago. I also get notably more short of breath when I try to do upper body exercises, such as lifting dumbbells. Interestingly, even with a super low FEV1’s, my O2 sats have remained pretty constant at 95-97% unless Im flaring, proving that the primary problem is with my airways, and not my alveoli, as is usually the case when distinguishing asthma from COPD.
So how low are these numbers gonna get?
So far Ive managed to adapt pretty well to the changes in my lung function, mainly because I exercise, but at point will it become a total struggle to breath all the time? At what number do the lungs trap so much air, or take in so little air that oxygenation is affected? At what number does the heart and other vitals organs start to fail as well? Is there a special number or warning sign on the test that will say.. “YOU HAVE ATTAINED THE LOWEST POSSIBLE FEV1 COMPATIBLE WITH LIFE”? Yikes!
Hey, Im a Respiratory Therapist and I should know these things, but I don’t, and I don’t think anyone really knows for sure. As an RT, Ive had patients with very severe COPD or Cystic Fibrosis who had FEV1s in the teens and even the single digits just prior to receiving a lung a transplant or just months from death. Ive also worked with paraplegics and people with neuromuscular conditions who naturally had super low numbers and who were eventually dependent on ventilators to stay alive, but there’s really no data on asthmatics with similarly low PFT numbers.
Of course spirometry alone is not the best way to determine longevity in people with obstructive lung diseases, the BODE Index is a much more accurate tool. It uses a multidimensional grading system that takes into account, not only FEV1, but also body mass index, the degree of breathlessness a person experiences, and exercise capacity. If I plug my numbers into that index, my outlook appears to be a lot more rosier than if you just go by my FEV1 and FVC. But then again, the BODE Index was designed primarily for COPD, not asthma. It doesn’t really take into account, the frequency, the unpredictability and/or severity of asthma flare ups. In any case, if you look at the BODE index closely, you’ll see how much exercise influences the other factors, and in that department I believe that’s the reason I continue to beat the odds.
Still, an FEV1 in the low 20’s is not a good sign and Im sure it will go lower. I try not to dwell on it, but I admit there are times, like when Im having a bad breathing day, or when Im in the hospital suffering through a really bad attack , or even when Im playing the role of research guinea pig, where these numbers really hits home. Regardless of the “numbers” ( and that’s all they are), I remain fairly positive and focus on the more enjoyable aspects of life. Albeit a little slower, Im still able to walk 1-3 miles everyday. I keep busy with a million other things and I continue to make semi long term plans as if my lungs were normal.