While there are many things that frustrate healthcare providers, obtaining home oxygen for a patient with Medicare easily makes the list. Recently, the family of a 90-year-old patient of mine with history of atrial fibrillation and congenital heart failure (CHF) called and asked if we could get their mom set up with home oxygen. Being diligent, I suggested they come in for a visit so we could assess her clinical status to see if there was a reversible cause for her increase in dyspnea on exertion, and figure out how best to treat it.
I saw her the next day and conducted a careful history and examination. Her examination was not impressive at rest, but she had a history of dyspnea on exertion. She was certainly not in florid CHF, but I did suspect that it was likely a contributor to her symptoms and made a couple of adjustments to her medical regimen. For her comfort, it seemed practical for her to have home oxygen, or an oxygen concentrator.
This is where Medicare guidelines can be a potential barrier when caring for our patients. If the request were for a knee brace, a back brace, or another item advertised on television by companies claiming that Medicare will pay for it, it would have been much easier to obtain. Those items are often not helpful or needed, but oxygen can be lifesaving, and can certainly provide an improved quality of life.
The problem is that the guidelines for oxygen coverage for Medicare are narrow, rigid, and not always practical. This is where pulse oximetry comes into play. While awake and resting, to be approved for coverage for home oxygen a patient must prove a pulse oximetry of 89% on room air and have a qualifying secondary diagnosis or pulse oximetry of ≤88%. My patient was about 93% on room air.
Another way for her to qualify was to obtain an oxygen saturation test during exercise and while breathing room air. If her level decreased to ≤88% and she demonstrated improvement with oxygen from the previous result, then Medicare would cover oxygen therapy.
So picture this: here I am walking down the hall with a frail 91-year-old woman with congestive heart failure who also has a lymphoma and metastatic breast cancer, trying to prove that she needs oxygen therapy. We are ambulating with her walker, trying to keep a pulse oximetry on her hand, which makes it difficult for her to grip the walker and makes it more challenging to obtain an accurate reading. After ambulating with a sufficient amount of discomfort, she sat down and her oxygen saturation would not register. When it started registering again it was 90%; just over the appropriate line for coverage. I was certain that because it took well over a minute to obtain a measurement that her saturation had to have been below 90.
In order to comply with Medicare guidelines, I had her ambulate with oxygen by nasal cannula with a tank in tow pulled by our medical assistant while I made sure she did not fall. Her oxygen level remained in the low 90s, but she was clearly more comfortable ambulating. Based on the guidelines, she probably did not meet strict criteria for oxygen coverage. However, clinically it was obvious she benefited from the addition of oxygen. I did end up getting her home oxygen, which she uses with exertion, and she now has improved quality of life and comfort.
My question is when did the pulse oximetry become the fifth vital sign? We need to be cautious not to base treatment just on pulse oximetry, but the overall clinical picture. For example, while supervising an intern on the pediatric floor, a 5-year-old girl was admitted with an asthma exacerbation, and the clinician was sending her down for a chest X-ray. When asked if he was going to give her another albuterol nebulization prior to the X-ray, he said that since her oxygen saturation was 95%, he felt the child could get the X-ray. However, a quick evaluation revealed that the girl was tachypneic, retracting, and had some tachycardia. Although her oxygen saturation was 95%, she was working quite hard to keep it there. After a nebulization treatment, her true vital signs all improved while her oxygen saturation remained stable.
My father was once in the hospital complaining of shortness of breath, and the nurses kept commenting that his pulse oximetry was 99%. A short time later, he suffered a fatal myocardial infarction. His dyspnea turned out to be an anginal equivalent and he was having unstable angina. Once again, while there is a place for pulse oximetry in caring for patients, physicians must be cautious not to place its value over history, exam, and good clinical judgement.