Myxoedema coma is the most extreme manifestation of hypothyroidism. It is a state characterised by three major features:
This condition is well described in articles dating back to the 1950s.. Concerned about the lack of recent publications, new authors have stepped up to fill the void in the new century. From the exam perspective, it certainly seems to occupy a position of eminince in the minds of the examiners, perhaps out of proportion to its prevalence. Among the past papers, the following SAQs have explored myxoedema coma:
Most cases tend to present during cold weather, where the ambient temeprature lowers the threshold for encephalopathy. These cases tend to be elderly women, fond of self-negect, given to squalor in the autumn of their life.
A great article form the American Family Physician goes through the various clinical features of myxoedema coma, which I have tabulated:
Cardiovascular collapse, shock
Decreased level of consciousness
Associated examination findings
A "puffy" face
Coarse, sparse hair
Prolonged PR interval
Decreased QRS voltages, especially in the limb leads
Deep T-wave inversions
The ECG changes of myxoedema were recently trotted out into Question 12.2 from the first paper of 2018, where the presentation of the 73 year old female patient was in a state of dishevelment and with hypothermia. The CICM examiners used this LITFL ECG for the paper, which comes from the LITFL page on ECG changes associated with hypothyroidism. Specifically, they used "Example 2 - Myxoedema coma (after treatment)". Presumably they thought the deep T-wave changes in the pre-treatment example would distract the trainees and everybody would put "AMI" as one of their main differentials.
Management of this condition consists of the following steps:
Summers, V. K. "Myxoedema coma." British medical journal 2.4832 (1953): 366.
Wartofsky, Leonard. "Myxedema coma." Endocrinology and metabolism clinics of North America 35.4 (2006): 687-698.
Mathew, Vivek, et al. "Myxedema coma: a new look into an old crisis." Journal of thyroid research 2011 (2011).
Lezama, Maybelline V., Nnenna E. Oluigbo, and Jason R. Ouellette. "Myxedema Coma and Thyroid Storm: Diagnosis and Management." Internal Medicine 14.Part 2 (2011): 1.
Chu, Michael, and Terry F. Seltzer. "Myxedema coma induced by ingestion of raw bok choy." New England Journal of Medicine 362.20 (2010): 1945-1946.
Wall, Cristen Rhodes. "Myxedema coma: diagnosis and treatment." American family physician 62.11 (2000).
Bondugulapati, Laxmi, Mohamed Adlan, and Lakdasa Premawardhana. "Thyroid Emergencies." Sri Lanka Journal of Critical Care 2.1 (2011): 1-12.