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Myxoedema coma (or myxoedema crisis) is a severe and potentially fatal form of decompensated hypothyroidism with an underlying cause. A low index of suspicion and a search for triggering factors should be the first step in dealing with the condition at an early stage. Myxoedema coma should be suspected in patients who present with hypothermia, altered mental status, and coma, even if hypothyroidism has not previously been recognized. The symptoms of hypothyroidism decompensation may mistakenly be attributed to its precipitating factors, which may include sepsis, cardiac failure, myocardial infarction, cerebrovascular accident, anaesthetic, sedatives, antidepressant medications, or metabolic and electrolyte abnormalities. Here, we present a case of myxoedema coma with two major underlying precipitating causes: septic shock and diabetic ketoacidosis.
Keywords: DKA, Hypothyroidism, Myxedema Coma, Septic Shock
Myxoedema coma is a severe and life- threatening form of decompensated hypothyroidism with an underlying precipitating factor. It can present with altered mental status, hypothermia, bradycardia, respiratory failure, and hyponatremia. Mortality rates may be as high as 25–60%, even with the best possible treatment [1-3].
Rizq Badawi , Ahmed Alsuliamani , Abdullah Alhejaili are with the Department of Emergency Medicine, King Fahd Medical City, Riyadh, Saudi Arabia (Emails: rizqbadwi@gmail.com, ahmed.alsulaimani95@gmail.com, Ab.h.1@hotmail.com), Eyad Alnemer is with the Emergency/Critical Care, Ministry of Health, Medina, Saudi Arabia. (Email: Eyadmn@hotmail.com) DOI: 10.52609/jmlph.v4i2.128
A low index of suspicion and a search for precipitating factors should be the initial step in dealing with myxoedema coma at an early stage [4]. Triggers may include poor medication compliance, thyroidectomy, acute events (including infection and cardiac infection among other stresses), and medical treatments that cause loss of thyroid homeostasis [5]. The mainstay of treatment includes hydrocortisone, intravenous liothyronine, levothyroxine, electrolyte correction, supportive therapies, and treating any underlying precipitant such as infection, surgery, or trauma [1,6]. Suspected myxoedema coma cases should receive intravenous hydrocortisone while awaiting laboratory results, as any delay can be life-threatening. The condition should ideally be managed in the intensive care unit (ICU) with pulmonary and cardiovascular support [7,8]. Here we report a case of myxoedema coma presenting with two main underlying precipitating factors: septic shock and diabetic ketoacidosis (DKA).
The patient was a 42-year-old male with a history of Down syndrome, epilepsy, and type 1 diabetes mellitus (T1DM). One year prior, he had required a 28-day admission to the ICU where he received treatment for pneumonia, ultimately recovering without complications. In the current admission, he was transferred from a primary hospital to the emergency department (ED) on October 18, 2023 having been intubated for septic shock secondary to pneumonia and DKA . Prior to his transfer, the patient had experienced three days of fever, cough, sore throat, decreased level of consciousness, and loss of appetite. Upon arrival at the Emergency Department, the patient was intubated for mechanical ventilation using a 7.5 mm endotracheal tube (ETT)
positioned at a depth of 22 cm. Ventilation was provided in the assist-control volume control (AC/VC) mode, with the following parameters: fraction of inspired oxygen (FiO2) 100%, tidal volume (Vt) 480 mL, positive end-expiratory pressure (PEEP) 8 cmH2O, and a respiratory rate of 20 breaths per minute. Oxygen saturation (SpO2) was recorded at 92%, and bilateral inspiratory crackles were noted. The patient was afebrile, with a blood pressure of 118/80 mm Hg, heart rate of 126 beats per minute, and random blood glucose level of 581 mg/dl. Venous cannulae (20 gauge) were secured, and the patient received ongoing sedation with fentanyl (100 mcg per hour) as well as norepinephrine (30 mcg per hour). He was following a protocol for the treatment of DKA, involving regular doses of insulin (7 IU), as well as potassium chloride at a dose of 15 meq in 500 ml fluid, administered intravenously at a rate of 250 ml per hour. Additionally, he had an indwelling urinary catheter (size F12 silicone), connected to a collection bag. However, despite this setup, only minimal urinary output was observed.
Management in the Emergency Department: The patient was connected to a cardiac monitor and a bolus of 1000 ml normal saline was administered. Intravenous medications were also administered, including a single dose of 5 mg midazolam followed by a continuous infusion at 5 mg per hour, and an increase in fentanyl infusion to 200 mcg per hour. Hydrocortisone 50 mg and meropenem 1000 mg were also administered. A right femoral central venous catheter (size 7) was inserted at a depth of 20 cm; vasopressin infusion was initiated at a rate of 0.04 IU per minute; and a 65-cm nasogastric tube (size F14) was inserted and confirmed via auscultation to be patent and intact. A urinary output of 200 ml was noted, which was amber in colour. Chest X-ray revealed bilateral infiltrations, while urine dipstick analysis showed significant levels of protein, glucose, ketones, and blood. Table 1 illustrates the patient’s venous blood gases along with the chemistry panel. The patient was admitted for DKA and septic shock secondary to pneumonia and showed no
As his TSH levels dropped, the patient started to stabilize vitally, regained consciousness, and was extubated. Another important tool in the management of severe hypothyroidism is glucocorticoids [15,16], due to the risk of adrenal insufficiency that accompanies this condition. In our case, a dose of hydrocortisone was given in the ED. In summary, myxoedema can easily be misdiagnosed, especially when symptoms are masked by other critical conditions ― in the case of our patient, septic shock complicated by DKA. Thus, suspicion should be raised even where there is no known history of hypothyroidism. While the mortality of myxoedema remains high, early recognition and treatment can play a major role in improving patient outcomes.
Myxedema coma should be suspected in patients presenting with hypothermia, altered mental status, and coma, even where there is no history of hypothyroidism, and particularly in those at greater risk for the condition, such as, in our case, people with Down syndrome. Many factors can trigger myxedema, including cold exposure, sepsis, DKA, and cardiogenic shock. Those at high risk should be investigated, given that mortality is high even with the appropriate management.
| Test | Result |
|---|---|
| Venous Blood | Gases |
| - pH | 7.12 |
| - Partial pressure of carbon dioxide (pCO2) | 47 mmHg |
| - Bicarbonate (HCO3) | 15 mmol/L |
| - Lactate | 4 mmol/L |
| - Base deficit | -16 mmol/L |
| CBC | |
| - White blood cells (WBC) | 8 x 10^3/μL |
| - Haemoglobin (Hgb) | 14 g/dL |
| Chemistry | Panel |
| - Creatinine | 235 U/L |
| - Urea | 8 mmol/L |
| - Potassium | 3.8 mmol/L |
| - Sodium | 144 mmol/L |
| Urine Dipstick | |
| - Protein | ++ |
| - Glucose | +++ |
| - Ketones | +++ |
| - Blood | ++ |
| The Journal of Medicine, Law & Public Health Vol | 4, No 2. 2024 p387 |
| improvement within the first 48 hours of | septum (IVS) were intact. The pericardium |
| admission. Severe metabolic acidosis, | appeared normal. |
| hyperkalaemia, oliguria, and pre-renal acute | A few days later, the patient showed |
| kidney injury (AKI) secondary to septic shock | improvement in terms of mechanical ventilation |
| all manifested simultaneously. Continuous renal | parameters and vasopressor requirements. He |
| replacement therapy (CRRT), anti- | was extubated and received dexamethasone 8 |
| hyperkalaemia treatment, and furosemide | mg twice daily for 24 hours. He showed |
| infusion were initiated. Despite these | improvement, with a Glasgow Coma Scale |
| interventions, the patient remained hypotensive. | (GCS) score of 13 out of 15. He continued to |
| An arterial line was inserted and vasopressors | improve over the following days; after 2 days he |
| were maximized, aiming for a 1-L negative fluid | was placed on a nasal cannula at 4 litres per |
| balance. | minute (LPM). |
| At that point, myxoedema coma was the main | The patient received a loading dose of |
| concern, especially when the thyroid- | intravenous levothyroxine (LT4) 200 mcg, |
| stimulating hormone (TSH) level came back | followed by a maintenance dose of 150 mcg, |
| very high; thus, T3 and T4 tests were ordered. | initiated on October 19, 2023. His TSH levels |
| The patient was not known to have suffered | decreased from 216 upon initiation, to 41 on 25 |
| from hypothyroidism before (his history was | October, 6 days later. This drop of >50 % in less |
| taken from his family). Nonetheless, his thyroid | than one week indicated an appropriate |
| function results confirmed the suspicion of | replacement. His T4 levels showed |
| myxoedema coma, which explains the masking | improvement, but remained low. |
| of expected hyperthermia due to septic shock | At that time, the patient became tachypnoeic and |
| (the patient showed a temperature of 36OC). On | desaturated while on a non-rebreather mask at |
| that day, IV thyroxine was started at 200 mcg | 15 L, maintaining SpO2 at 91 % with a GCS |
| stat, and then reduced to 150 mcg daily. | score of 15/15. CT chest revealed |
| The following day, the patient began to | bronchiectasis. There was a rapid progression of |
| experience oro-nasal bleeding during | bronchiectasis cavitation on the right side with |
| suctioning, with secretions appearing | new consolidation in the basal left side, likely |
| moderately thick and bloody. Additionally, | attributed to Pseudomonas or Staphylococcus |
| thrombocytopenia was observed, with a platelet | infection. Emphasis was placed on obtaining |
| count of 17x 10^3/μL, along with acute liver | sputum and secretion cultures with |
| failure indicated by elevated levels of aspartate | antibiograms, IV colistin and IV imipenem for |
| aminotransferase (AST) at 4223 U/L and | treatment. |
| alanine aminotransferase (ALT) at 4248 U/L. | 15 days post-admission, the patient developed |
| To address these complications, the patient | drowsiness, hypotension, increased tachypnoea, |
| received nebulized tranexamic acid, along with | and desaturation despite the non-rebreather |
| a transfusion of 4 units of fresh frozen plasma | mask and BiPAP. His platelet count was 17 x |
| (FFP) and 6 units of platelets (PLT). Intravenous | 10^3/μL. Consequently, he was reintubated on |
| N-acetylcysteine was initiated at a dose of | the same day and received a transfusion of 6 |
| 12000 mg over 1 hour, followed by 4000 mg | units of platelets. Although a bronchoscopy had |
| over 4 hours, and then 8000 mg over 16 hours. | been planned, it was not performed due to the |
| Echocardiography revealed fair left ventricular | patient’s deteriorating condition. |
| systolic function with an ejection fraction (EF) | 25 days post-admission, the patient was in pre- |
| of 50 %. Cardiac dimensions were within | arrest status with refractory septic shock |
| normal limits, valves were normal, and the right | (despite norepinephrine and vasopressin |
| side size and function were also normal. No | infusion at high doses) and multi-organ failure. |
| masses or thrombi were observed and both the | He arrested at 4:48 AM; as the rhythm showed |
| The Journal of Medicine, Law & Public Health Vol | 4, No 2. 2024 p388 |
| (PEA), cardiopulmonary resuscitation (CPR) | hypotension, diagnostic and management |
| performed and return of spontaneous circulation | measures should be implemented as soon as |
| (ROSC) was achieved after 12 minutes. | possible for patients presenting with known |
| Venous blood gas post-ROSC showed pH 7.0, | hypothyroidism, thyroidectomy, hypothermia, |
| pCO2 90 mmHg, HCO3 16 mmol/L, lactate 22 | and altered mental status, as mortality is high |
| mmol/L, and potassium 6.5 mmol/L. | even with the best treatment [10]. |
| Electrocardiogram (ECG) revealed no acute | Annually, an estimated 7.9 million infants are |
| dynamic changes. Nonetheless, two hours later, | born with a serious birth defect caused by |
| the patient arrested again. CPR was performed | genetic or largely genetic origin. The most |
| for 40 minutes with no response, and death was | frequent severe aneuploid condition at birth is |
| declared. | Down syndrome, which was initially reported in |
| II. DISCUSSION | 1866 by the British physician Dr. John Langdon |
| H. Down [11]. Despite their small and | |
| We report a case of myxoedema coma caused by | overweight look, most children with Down |
| DKA and septic shock in a 42-year-old | syndrome have normal thyroid function, while |
| individual with a medical history including | adults with Down syndrome tend to be more |
| Down syndrome, epilepsy, and type 1 diabetes | prone to both hypothyroidism and |
| mellitus, who at the ED intubated for septic | hyperthyroidism. Hypothyroidism may be |
| shock caused by pneumonia and DKA. This | caused by the late development of thyroid |
| case is particularly unique in terms of the | autoantibodies; testing thyroid-stimulating |
| clinical course. To the best of our knowledge, | hormone (TSH) and blood thyroxine (T4) |
| there has been no mention in the literature of | levels, as well as triiodothyronine (T3) and T3 |
| myxoedema coma triggered by DKA and septic | resin uptake, can assist in diagnosing the |
| shock. Previous small case-series investigations | condition as well as weight loss, lethargy, heat |
| found the mortality rate for myxoedema coma to | sensitivity, and skin abnormalities. |
| be 36% (4 out of 11 patients), 52% (12 out of 23 | In the present case, our patient had no history of |
| patients), and 25% (2 out of 8 patients) [9]. Due | hypothyroidism, despite Down syndrome |
| to the condition’s rarity, the clinical | patients having a high prevalence for thyroid |
| presentation, prognosis, and outcome were | diseases such as thyroiditis and congenital |
| poorly Analysis Japan revealed recognized. of a nationwide that, out of 19 inpatient million database inpatients, in | hypothyroidism pneumonia complicated [12,13]. He by septic was suffering shock; there from |
| 149 were diagnosed with myxoedema coma, | was no fever mentioned in the history prior to |
| with a mean age of 77 years and two-thirds of | his arrival at the hospital, and his temperature |
| them women [9]. A retrospective multicentre | during hospitalization was 36-37OC. We believe |
| cohort study, by Simon Bourcier et al., of | this was due to myxoedema and the absence of |
| critically ill severe hypothyroidism patients in | thyroid hormone thermogenesis. |
| intensive care, found that the clinical | Typical presentation of patients with |
| presentation was hypothermia in 66% of cases, | myxoedema may include hypothermia, dry skin, |
| hemodynamic failure in 57%, and coma in 52%. | hoarseness, and altered mental status; however, |
| Furthermore, 54% were undiagnosed with | the absence of these symptoms does not rule out |
| hypothyroidism prior to ICU admission. Severe | the diagnosis [14]. It is worth noting that sepsis |
| hypothyroidism can be triggered by the | or DKA may be atypical manifestations of |
| termination of levothyroxine medication, sepsis, | myxoedema, and the condition should thus be |
| or amiodarone-related hypothyroidism. | considered in patients presenting with these |
| Although it is difficult to suspect | symptoms. In the present case, early recognition |
| hypothyroidism in the emergency department | and treatment starting with supportive |