Stories from the Stethoscope: September 2021

I was called into the Emergency department for a patient of mine who appeared very sick. Ms. Lee was in her 50’s. She lived in a group home with twenty-four-hour care. She had an intellectual and developmental disability (I/DD) without a known cause. She had limited verbal ability but became withdrawn, confused, stopped ambulating, and had a temperature of 99.9 °F. Her blood pressure was very low. We assumed she had a bad infection, held almost all her medications and provided IV antibiotics and IV fluids. Her blood work and her vitals normalized, and her status improved nicely. Within a week she was discharged. No cause was identified. All tests for infection were negative. She was discharged without a diagnosis. As her mentation improved, we restarted all her medications for her behaviors and seizures. 

Within a month she came back to the hospital with the same symptoms. We provided the same course of therapy, and she began to improve. No signs of infection again. I was fascinated by this case. I wondered what variable I was missing? As I went through all the data the only constant was the medication she was taking. I kept coming back to the antipsychotic she was on. I believed she may have Neuroleptic Malignant Syndrome (NMS) from her medication. Neuroleptic Malignant Syndrome is a rare but potentially life-threatening reaction to the use of medications. It is only seen in about 1 or 2 out of every 10,000 people taking antipsychotics. It can be characterized by high fever, muscle rigidity, confusion, and abnormal muscle enzyme elevation. I discussed this with the team of doctors consulting on this case. The response I got was that the temperature was not high enough. They have never seen a case with a temperature as low as hers. I was not satisfied. I went back and reviewed her office chart. I was struck by a new finding that I never noticed. Her baseline temperature was 96 °F. Numerous office visits revealed the same values. The real key to the equation was not the absolute temperature but the change from baseline. A four-degree increase in temperature with all the other symptoms was consistent with NMS. I did not restart the medications upon discharge. I talked to her psychiatrist, and we never renewed that class of medication again. The symptoms never returned.

As excited as I was about this discovery, it made me change my lens to what is considered normal. Let’s look at each patient and understand what is the normal value for each patient. This expanded to not only temperature values but blood tests for white blood cells, drug levels, and beyond. Normal values are based on a bell-shaped curve. They usually account for 95% of all results. Anyone who treats individuals with I/DD understands our patients often fall outside that range.

We have since discovered numerous alterations in treatment options for patients once we understood their individual normal values. There is a saying in medicine that says, “When you hear hooves, think horse, not zebra.” I believe this to be true but remember there are hundreds of different breeds of horses. We need to look for the common causes as long as we have our feet firmly planted when we are listening to the sounds we are supposed to hear.