15. The Fingerstick


It was a snowy night and I was on call again. I liked it. Sometimes the cold could be very warming. Anyway, that’s what I was thinking about while waiting for my coffee at the cafeteria. I had brought my own that day, but I had already drunk all of it - shifts can do that to you.

It was a busy night. I had seen so many patients I could barely remember my own name. But I was also loving it, I was feeling the flow, you know? When you’re so into what you’re doing that you don’t even notice how time goes by, and you don’t even care if it takes longer than it was supposed to. I used to admire that in some of my teachers, and now I was feeling it myself.

Approximately in the middle of the shift, an old lady was admitted. She was 87 years old and so tiny you could almost miss her. She lived in a nursing home for some time already and had no one with her at the hospital. I went to talk to her.

‘Mrs. Juliet Brennan, correct? I’m Dr. Lisa Diaz and I’ll be taking care of you today. How can I help you?’

She smiled and took a little while to respond.

‘Nice to meet you, Dr! I don’t really know why I’m here actually. I fell at the home where I live, but I’m fine, it was a minor fall.’

‘I see, and why did you fall? Were you feeling weak or did you lose consciousness?’

‘No, not at all! I tripped in that damn cart they leave in the hallway,  I always tell them to take that thing out of there.’ She cursed. ‘But they insisted on taking my blood pressure and stung my finger to see my blood sugar.’

‘And how were those?’

‘My blood pressure was fine, but they said my blood sugar was 20 mg/dl. I told them there was no way, it was wrong, I felt great! Anyway, they sent me here after that.’

I was impressed, 20 mg/dl was too low. This was very strange. How could she be totally fine being so hypoglycemic? Or maybe she wasn’t fine but didn’t want to admit it. Either way, I told her I would have to run some tests to check that.

I hadn’t noticed anything out of the ordinary in the physical exam, although I was too tired to be sure, and Mrs. Juliet was very well oriented. In her medical history, there was nothing of note, and she didn’t have any other complaints other than occasional heartburn.

I ordered a plasma glucose level, insulin, and C-peptide, but at the last minute, I decided to add a fingerstick glucose test to make a comparison. Maybe she was right and the nursing home needed to change their measuring device.

While I waited for the results I went to get another coat. It really was freezing. I found Jax on the way and we chatted a little bit, but he was busy and so was I, so he couldn’t help me with the case.

I was surprised by the results when I got them. Her blood glucose was normal, 89 mg/dl, and her insulin and C-peptide were also normal. However, her finger stick glucose was 18 mg/dl. It was just so unlikely, how could both glucose meters be so wrong?

I went to talk to the nurses and asked them about it. They measured it all the time, they would know if it was working or not. After asking a few of them they assured me it was working, even the nurse that measured in Mrs. Brennan assured it.

Well, since there was no sign that she had been hurt in the fall and she was not hypoglycemic, there was no reason to keep her there. But I was still troubled with that discrepancy. There must have been some explanation for the artifactual hypoglycemia in the glucose meter. I was missing something.

I decided to examine her again. I always remembered Lucy, ‘If you don’t know the diagnosis yet, you need more information.’

‘Hi, Dr. Diaz. How was my blood sugar after all?’

‘It turns out you were right, Mrs. Brennan! Your blood sugar was normal, but the fingerstick test was wrong again.’

‘Really? It must be this cold, my hands get especially cold in the winter.’

When she said that, I noticed her hands. They were white at the fingers, an obvious Raynaud’s phenomenon. But that was not all, she had slightly deformed fingers, which I had seen earlier but attributed it to her age and probably some degenerative condition like osteoarthritis.

That reminded me of her heartburn. She already had 3 of the features of CREST syndrome: Raynaud’s, esophageal dysmotility, and sclerodactyly. I then turned to her face and could see the telangiectasias, which I had also dismissed earlier. By touching her skin I could feel the stiffness of the calcium deposits in her hands. It was all so clear now, I hadn’t even realized I had left an awkward silence.

‘Is everything okay, Dr. Diaz?’

‘Yes, yes it is! I’m sorry. But it turns out you were right again Mrs. Juliet.’ I smiled at her. ‘Your fingerstick glucose test was wrong because of the cold, sort of actually.’

She seemed interested.

I explained to her that I thought she had a connective tissue disease called CREST syndrome, which stands for Calcinosis cutis, Raynaud’s phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasias. She had all the symptoms and some connective tissue disorders can falsify capillary glucose because of poor capillary blood flow.

‘It’s a good thing that we found out now, Mrs. Brennan, because we can treat it to delay the progression of the disease. I’ll just order a test to confirm it.’

Although I tried my best to explain it to her, I’m not sure she understood much of what I said. At least she was happy that she could go home soon and tell her caregivers she was right about her blood glucose. ‘I know my body, those people never believe me.’

When I got home that day I was excited to tell Jax all about this case, but he wasn’t there. I went to the fridge for a soda and for the first time in a long time, I felt alone. I had no one to tell about the case. Even Mrs. Brennan had the nurses to talk to, and I had no one. Most of the friends I used to have were not close anymore, since I had absolutely no time to keep those friendships going. 

I only had Jax. And that night it hit me that I wouldn’t have him forever, he would marry Meg someday in the near future and I would be living alone and friendless.

I decided then to call my mom. She lived far but we never lost touch. True, we weren’t calling each other that much then. But that was my fault. I had let the work drown me and I was always in a rush. No wonder I didn’t have many friends.

But thank God for mom. I called her and she was happy for me. But of course, she noticed something was off. Mothers always do.

‘What’s wrong, sweetie?’

I smiled sadly.

‘I think I need more friends.’


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Ab: antibody; Tt: treatment.

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