A 67-year-old woman, with history of rheumatoid arthritis (RA), heart failure (HF), chronic renal failure (CRF), obesity, and obstructive sleep apnea (OSA), presented with malaise and abdominal pain. A mild pancreatitis was diagnosed. Two days later she was transferred from the floor to our ICU, with history of progressive dyspnea, tachypnea, and low SpO2. At admission, her vitals were: GCS 15, HR 98, BP 104×55, RR 24, SpO2 88% on room air, temp. 37°C (98.6°F to our “I do not follow the rest of the world measuring system” friends).
Ok, my first impression was although she didn’t look severely ill, she didn’t look “let’s do some push-ups” good. Her lungs seemed to be fine after auscultation, her abdomen was ok (she was already eating), and her physical was unremarkable. Was this CHF? PE? Infection? So, we picked up our sound wave propeller and performed a good old POCUS. Heart: OK. FAST: OK. No DVT. And the lung:
When we first saw this image, we thought, well, irregular subpleural consolidation, some B-lines, no pleural effusion. Just adjacent to that area, a normal lung with a smooth pleural surface was viewed. Subpleural images open a wide variety of differentials: infection, PE, atelectasis, metastasis, primary tumor… Was this a pulmonary infarct? Pneumonia?
But our patient had no fever, no leucocytosis, negative procalcitonin; we couldn’t find any DVT… What is going on here? Remember, when performing a lung ultrasound it is wise, to say the least, to scan both lungs entirely. And, to our surprise, we started to see images just like this one in other lung areas (lower right, lateral right, upper and lower left).
We accessed our patient’s records and found a CT image from a few months before. Several rheumatoid lung nodules were visible. The image below shows the area we scanned.
Of course, rheumatoid lung nodules didn’t come to our minds until we saw the CT scan. They are a pretty rare pulmonary manifestation of RA, most of the time asymptomatic, and located in subpleural regions . Again, this wasn’t in our initial differentials; however, the clinical examination, lab, and the lung ultrasound findings didn’t fit any of our differentials. Instead of giving her antibiotics and everything else, we put her on BiPAP and waited. In the meantime, we saw that somebody forgot to prescribe the steroids she had been using for a while, probably another factor related to her decompensation. She got better and was sent back to the floor two days later.
And always remember: each time you stop your scan after a positive finding, Daniel Lichtenstein has a minor stroke.
1- Shaw M, Collins BF, Ho LA, Raghu G. Rheumatoid arthritis-associated lung disease Eur Respir Rev. 2015; 24(135):1-16.