We report a single center experience of an increased incidence of MC in the time period from the beginning of COVID-19 pandemic until present. Although several case reports of severe hypothyroidism and MC diagnosed in patients with COVID-19 have been published [12–14], we have identified only one case report of an exacerbation of hypothyroidism leading to MC during the COVID-19 lockdown [16]. To our best knowledge, this is the first report of an increased incidence of MC in the period of COVID-19 pandemic, when access to primary care services was very limited, and in the early post-pandemic era, when long-term consequences of the lock-down are expected to manifest.
Besides thyroid hormone concentration measurement, the objective clinical severity of hypothyroidism of the patients included in our cohort was assessed by the MC score, as proposed by Popoveniuc et al. (Table 1) [3]. In addition to the state of conciousness, the parameters composing this score include the presence of a precipitating factor, body temperature, electrolyte, metabolic, cardiovascular, respiratory and gastrointestinal disturbances. Moreover, it has been suggested that the term MC can be misleading, since not all patients with severe hypothyroidism present with coma. Hemodynamic and ventilation failures are also frequent clinical presentations associated with worse outcomes [4–5, 17]. The validity of the MC score for diagnosing severe hypothyroidism was confirmed by two recent larger studies for patients with primary but also central hypothyroidism [4, 17].
Hypothyroidism was diagnosed de novo in two patients; in the majority, the severe form of hypothyroidism was due to a long-standing therapy non-compliance. Since the patients were severly hypothyroid, we were unable to establish the duration of non-compliance from their clinical history with precision. Discontinuation of levothyroxine was also described as one of the most common triggers for critically-ill severe hypothyroidism in a large French cohort [4].
In MC, both the initial dose and the route of administration of levothyroxine are still a matter of debate as aggressive levothyroxine replacement at the onset of SH treatment may increase the risk of myocardial infarction or arrhytmias [19]. Therefore, levothyroxine replacement in the context of SH should be pragmatic and adapted to the patient’s age, medical history and general condition. Due to the inaccessibility of parenteral levothyroxine, our patients were treated with oral, mostly liquid, levothyroxine, as previously described[18, 20–21, 24] and with the use of a liquid form of levothyroxine in rectal infusions, which may provide additional clinical benefit in patients with malabsorption secondary to paralytic intestinal obstruction. The lack of clinical improvement associated with the low initial levothyroxine dose, used in some patients before admission to the endocrinology department, confirms the need for initial treatment with high levothyroxine doses, considering the possibility of impaired intestinal absorption. The mortality of our cohort was similar as recently reported [4–5].
A long time lag between the start of a health crisis such as the COVID-19 pandemic and the manifestation of severe clinical consequences of inadequate management of hypothyroidism was expected since most effects of thyroid hormones are mediated through binding to nuclear receptors and modulating the expression of thyroid hormone-responsive genes [22]. Therefore, usually there is a long period between the onset of hypothyroidism and overt clinical picture. In addition, the initial symptoms and signs of hypothyroidism can be vague, wide-ranging and non-specific [22]. MC is defined as an extremely rare form of severe hypothyroidism that usually occurs after a long period of unrecognized or poorly controlled thyroid hypofunction [3].
The guidance on the management of thyroid dysfunction during the COVID-19 pandemic, published with the aim to optimize patient care during the COVID-19 health crisis, suggested remodelling some of the endocrine services to telephone and video consultations and remote monitoring services; however, it did foresee that patients with thyroid dysfunction will not be managed as closely as in a non-crisis situation [7]. The Polish National Health Program for 2021–2025 emphasized that the COVID-19 epidemic has caused a negative synergistic effect [15]. The Patients Rights Ombudsman’s Report has shown that exclusion of some general hospitals and their transformation into COVID-19-dedicated hospitals has made it much more difficult for patients using these units to access health services and has heightened their concerns about the continuity of treatment [23]. In addition, the spread of the SARS-CoV-2 virus has affected the use of medical services in Poland. Comparing data from July 2018 and July 2020, a Center for Public Opinion Research found that there was a clear increase in the overall number of people who did not receive any treatment and examinations (from 12–30%) [24]. In a study aimed to assess patients’ perspectives on the impact of the COVID-19 pandemic on the treatment and diagnostic process in Poland, 64.3% of the respondents rated the process negatively [15]. Increased focus on the medical problems associated with COVID-19 and the gradual development of symptoms, inadequate information and the lack of sufficient communication with patients and their relatives have been identifided as the main impediments.