Myxoedema Coma Diagnostic Score Calculator
Myxoedema Coma Diagnostic Score Calculator
Score the six domains of the Popoveniuc diagnostic system for myxoedema coma — thermoregulatory, neurological, gastrointestinal, cardiovascular, metabolic and the precipitating event.
Myxoedema coma diagnostic score
6 domains → 0–230 pointsAn elderly woman brought in after a fall at home in winter. Temperature 34 °C, stuporous, reduced bowel sounds with no ileus, heart rate 44 with a prolonged QT, blood pressure 82/50, sodium 122 mmol/L, PaCO₂ 7.1 kPa, creatinine raised, no pericardial effusion, no pulmonary oedema, normal heart size, glucose normal, oxygenation adequate, and a chest infection as the precipitant
Six domains, two of them additive
- Cardiovascular
- additive: a bradycardia band (0–30) plus ECG changes 10, effusion 10, pulmonary oedema 15, cardiomegaly 15 and hypotension 20 — up to 100 points
- Metabolic
- additive: hyponatraemia, hypoglycaemia, hypoxaemia, hypercarbia and reduced GFR, 10 points each — up to 50
- Thermoregulatory, CNS, gastrointestinal
- single choice within each domain
- Precipitating event
- 10 points if present. Nearly every case has one
- Thresholds
- 25 and 60. Because every item is a multiple of five, the bounds are written as 24 and 59 here and mean exactly what the published table means
- What it is not
- a severity or mortality score, and not a reason to wait. It is a diagnostic aid
Worked example
An elderly woman brought in after a fall at home in winter. Temperature 34 °C, stuporous, reduced bowel sounds with no ileus, heart rate 44 with a prolonged QT, blood pressure 82/50, sodium 122 mmol/L, PaCO₂ 7.1 kPa, creatinine raised, no pericardial effusion, no pulmonary oedema, normal heart size, glucose normal, oxygenation adequate, and a chest infection as the precipitant
Thermoregulatory: 34 °C is in the 32–35 °C band → 10
CNS: stupor → 20; gastrointestinal: decreased intestinal motility → 15
Cardiovascular: heart rate 44 → 20, other ECG changes → 10, hypotension → 20, no effusion, no pulmonary oedema, no cardiomegaly → subtotal 50
Metabolic: hyponatraemia 10, hypercarbia 10, reduced GFR 10, glucose and oxygenation normal → subtotal 30
Precipitating event present → 10
10 + 20 + 15 + 50 + 30 + 10 = 135 points
135 is well above 60 → highly suggestive of myxoedema coma. Note that the cardiovascular and metabolic domains supply 80 of the 135, which is the usual pattern
The Popoveniuc diagnostic scoring system in full
| Domain | Finding | Points |
|---|---|---|
| Thermoregulatory dysfunction | Temperature above 35 °C (95 °F) | 0 |
| Thermoregulatory dysfunction | 32 – 35 °C (89.6 – 95 °F) | 10 |
| Thermoregulatory dysfunction | Below 32 °C (89.6 °F) | 20 |
| Central nervous system effects | Absent | 0 |
| Central nervous system effects | Somnolent or lethargic | 10 |
| Central nervous system effects | Obtunded | 15 |
| Central nervous system effects | Stupor | 20 |
| Central nervous system effects | Coma or seizures | 30 |
| Gastrointestinal findings | Absent | 0 |
| Gastrointestinal findings | Anorexia, abdominal pain or constipation | 5 |
| Gastrointestinal findings | Decreased intestinal motility | 15 |
| Gastrointestinal findings | Paralytic ileus | 20 |
| Cardiovascular dysfunction (additive) | Bradycardia absent | 0 |
| Cardiovascular dysfunction (additive) | Heart rate 50 – 59 | 10 |
| Cardiovascular dysfunction (additive) | Heart rate 40 – 49 | 20 |
| Cardiovascular dysfunction (additive) | Heart rate below 40 | 30 |
| Cardiovascular dysfunction (additive) | Other ECG changes | 10 |
| Cardiovascular dysfunction (additive) | Pericardial or pleural effusion | 10 |
| Cardiovascular dysfunction (additive) | Pulmonary oedema | 15 |
| Cardiovascular dysfunction (additive) | Cardiomegaly | 15 |
| Cardiovascular dysfunction (additive) | Hypotension | 20 |
| Metabolic disturbances (additive) | Hyponatraemia | 10 |
| Metabolic disturbances (additive) | Hypoglycaemia | 10 |
| Metabolic disturbances (additive) | Hypoxaemia | 10 |
| Metabolic disturbances (additive) | Hypercarbia | 10 |
| Metabolic disturbances (additive) | Decreased glomerular filtration rate | 10 |
| Precipitating event | Absent | 0 |
| Precipitating event | Present | 10 |
How the thresholds performed, and on how many patients
| Figure | |
|---|---|
| Derivation cohort | 21 patients at one institution — 14 with myxoedema coma, 7 controls |
| Validation | 22 published case reports |
| Sensitivity of a cut-off of 60 or more | 100% |
| Specificity of a cut-off of 60 or more | 85.7% — which, on seven controls, is one control misclassified |
| Area under the ROC curve | 0.88 |
| Bands | Below 25 unlikely · 25 – 59 suggestive · 60 or more highly suggestive |
Two different scores, two different jobs
| This score | Burch-Wartofsky | |
|---|---|---|
| Condition | Myxoedema coma — decompensated hypothyroidism | Thyroid storm — decompensated thyrotoxicosis |
| Direction | Too little thyroid hormone | Too much thyroid hormone |
| Temperature | Hypothermia scores | Hyperpyrexia scores |
| Heart rate | Bradycardia scores | Tachycardia scores |
| Thresholds | 25 and 60 | 25 and 45 |
| On this site | This page | Burch-Wartofsky score calculator |
A diagnostic aid for an emergency that is treated on suspicion
Myxoedema coma is decompensated hypothyroidism, and it is rare, lethal and badly named. Most patients are not comatose: the neurological picture runs from drowsiness through obtundation to stupor, and coma and seizures sit at the far end of a spectrum rather than defining the condition. What defines it is a combination — hypothermia, a depressed conscious level, bradycardia and hypotension, hyponatraemia, carbon dioxide retention, a sluggish or obstructed gut — usually in an older patient, usually in winter, and almost always with a precipitant, whether an infection, an operation, cold exposure, a sedative or a few weeks off levothyroxine. Popoveniuc and colleagues built this scoring system to give that combination a structure, because no single finding makes the diagnosis and the individual findings are each common for other reasons.
Two of the six domains add rather than choose, and getting that wrong is the commonest way to under-score a real case. The cardiovascular domain takes a bradycardia band worth up to 30 points and then adds ECG changes, a pericardial or pleural effusion, pulmonary oedema, cardiomegaly and hypotension on top — up to 100 points from that domain alone. The metabolic domain adds five independent items worth 10 each. A patient who is bradycardic and hypotensive and has a prolonged QT scores 50 for the cardiovascular domain, not 20, and this calculator asks about each of those separately and prints the two subtotals beside the answer so they can be checked. Thermoregulatory, neurological and gastrointestinal are single-choice, as the chart intends.
The thresholds are 25 and 60: below 25 the authors describe the diagnosis as unlikely, 25 to 59 as suggestive, and 60 or more as highly suggestive. The performance behind those numbers is worth stating openly rather than burying. The score was derived on 21 patients at a single institution — 14 with myxoedema coma and 7 controls — and validated against 22 published case reports, and at a cut-off of 60 or more it was 100% sensitive and 85.7% specific with an area under the curve of 0.88. A specificity of 85.7% on seven controls is one control misclassified. Case reports, meanwhile, are selected for being florid enough to publish, which is the least demanding validation set imaginable. So this is a tool for recognising and communicating a picture, and for deciding to escalate; it is not an instrument with the precision to rule the diagnosis out.
Which brings the point that matters most on this page. Nothing here waits for a score. Myxoedema coma carries a reported mortality of the order of a quarter to a half even with treatment, and the treatment is started on suspicion: intravenous thyroid hormone, hydrocortisone until adrenal insufficiency has been excluded — because giving thyroid hormone first to a patient with unrecognised adrenal insufficiency can precipitate a crisis — passive rewarming rather than active external warming, ventilatory and haemodynamic support, careful correction of the hyponatraemia, and an active search for the precipitant. Thyroid function tests and a cortisol go off at the same time as the first dose, not before it. A score of 30 in a patient who looks like this is a reason to treat and to call for help, not a reason to wait and rescore. Note also that this is a diagnostic instrument and not a prognostic one: a separate and later score has been proposed for predicting mortality in myxoedema coma, with different items and different thresholds, and it is not this one and should not be confused with it. This supports a clinician’s judgement rather than replacing it. It is arithmetic on the figures entered, and it knows nothing about the patient in front of you.
Frequently asked questions
What score is diagnostic of myxoedema coma?
Popoveniuc et al describe a total below 25 as making the diagnosis unlikely, 25 to 59 as suggestive, and 60 or more as highly suggestive. At a cut-off of 60 or more the score was 100% sensitive and 85.7% specific in the derivation cohort, with an area under the curve of 0.88.
Which domains add up rather than choosing one option?
The cardiovascular and metabolic domains. Cardiovascular adds a bradycardia band of up to 30 points to ECG changes (10), effusion (10), pulmonary oedema (15), cardiomegaly (15) and hypotension (20) — up to 100 points. Metabolic adds hyponatraemia, hypoglycaemia, hypoxaemia, hypercarbia and reduced GFR at 10 points each.
Should treatment wait for the score?
No. Myxoedema coma is a medical emergency with a reported mortality of the order of a quarter to a half even when treated, and it is treated on clinical suspicion — intravenous thyroid hormone, hydrocortisone until adrenal insufficiency is excluded, passive rewarming and critical care support. The score structures and communicates the impression; it does not gate the treatment.
How well validated is this score?
Weakly, and the figures should be read with that in mind. It was derived on 21 patients at one institution, 14 of them with myxoedema coma and 7 controls, and validated against 22 published case reports. A specificity of 85.7% on seven controls means one control was misclassified, and published case reports are selected for being florid.
Does the patient have to be comatose?
No, and most are not. The neurological domain scores somnolence or lethargy at 10 points, obtundation at 15 and stupor at 20, with coma or seizures at 30. The name of the condition is misleading and has probably contributed to it being missed.
Related calculators
References
- Popoveniuc G, Chandra T, Sud A, et al. A diagnostic scoring system for myxedema coma. Endocr Pract. 2014;20(8) — page range not confirmed from a source that displayed it.
- Myxedema Coma Diagnostic Score, published in Evidence to Action (MDCalc) — reproduces the full Popoveniuc point table and reports the derivation cohort of 21 patients (14 with myxoedema coma, 7 controls), validation against 22 literature cases, and a cut-off of ≥60 as “100% sensitive and 85.7% specific for MC diagnosis, with an AUC of 0.88”.
- Table I, Diagnostic Scoring System for Myxedema Coma — the scanned table published with a clinical decision-support monograph and footnoted to Popoveniuc et al, Endocr Pract 2014. The second of the two independent reproductions cross-checked for this page.
- Jonklaas J, Bianco AC, Bauer AJ, et al. Guidelines for the treatment of hypothyroidism. Thyroid. 2014;24(12):1670–751.
- A prognostic myxoedema score has separately been proposed and is a different instrument from the diagnostic score on this page: J Endocrinol Invest. 2022. doi:10.1007/s40618-022-01884-6, whose authors report scores above 90 predicting higher mortality and above 110 predicting 100% mortality on their own scale.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.