Discussion
Thyroid storm may be caused by various stresses, such as infection, trauma, and surgery in a patient with untreated or poorly controlled underlying thyroid disease, resulting in an overproduction of thyroid hormones that can lead to multiple organ malfunctions. In Japan, the annual incidence of thyroid storm is 0.2per 100,000, and the mortality rate of patients from thyroid storm is approximately 11%[1]. Thus, thyroid storm is a rare but life-threatening condition requiring urgent treatment.
In general, thyroid storm is diagnosed according to the Burch-Wartofsky criteria[2]. Retrospectively, it was obvious that our patient had all the telltale signs, and we calculated the patient’s score to be 105(a score greater than 60 is consistent with thyroid storm). Therefore, it would have been easy to make a diagnosis of thyroid storm had we been more aware of the condition. Unfortunately, it was not until we performed a tracheotomy that we were led to suspect hyperthyroidism due to the abnormal development of blood vessels around the thyroid. Since we did not have previous knowledge or experience of a thyroid storm, we were trying to deal with each symptom individually until the correct diagnosis.
The differential diagnosis of thyroid storm includes cardiogenic shock, malignant hyperthermia, and sepsis. In this case, we had performed mitral repair on the patient due to reduced cardiac function. Therefore, we initially assumed that the respiratory failure and tachycardia were caused by severe heart failure. In addition, our patient had Becker muscular dystrophy as a co-morbidity, which has known to be a risk factor for malignant hyperthermia related to general anesthesia[3]. This condition also made the diagnosis difficult.
There have only been a few case reports of thyrotoxicosis and thyroid storm in the peri-operative period of open-heart surgery, all of which occurred in coronary artery bypass grafting and were associated with coronary artery spasm and increased myocardial oxygen demand[4-8]. To the best of our knowledge, this is the first case report of thyroid storm occurring after cardiac valve surgery.
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Availability of data. All the co-authors have full access to the patient data. Also, the datasets during and/or analyzed during the current study available from the corresponding author on reasonable request.
Conflicts of interest . The authors declare that they have no competing interests.
Funding. None
Authors’ contributions . All authors contributed to the writing of the final manuscript.