Hyponatremia as the presenting manifestation of Sheehan's syndrome in elderly patients

Sheehan syndrome

Sheehan syndrome or postpartum hypopituitarism is a condition characterized by hypopituitarism due to necrosis of the pituitary gland. The initial insult is caused by massive postpartum haemorrhage (PPH), leading to impaired blood supply to the pituitary gland, which has become enlarged during pregnancy. Small sella turcica size, vasospasms (caused by PPH) and/or thrombosis (associated with pregnancy or coagulation disorders) are predisposing factors; autoimmunity might be involved in the progressive worsening of pituitary functions. Symptoms are caused by a decrease or absence of one or more of the pituitary hormones, and vary, among others, from failure to lactate and nonspecific symptoms (such as fatigue) to severe adrenal crisis. In accordance with the location of hormone-secreting cells relative to the vasculature, the secretion of growth hormone and prolactin is most commonly affected, followed by follicle-stimulating hormone and luteinizing hormone; severe necrosis of the pituitary gland also affects the secretion of thyroid-stimulating hormone and adrenocorticotropic hormone. Symptoms usually become evident years after delivery, but can, in rare cases, develop acutely. The incidence of Sheehan syndrome depends, to a large extent, on the occurrence and management of PPH. Sheehan syndrome is an important cause of hypopituitarism in developing countries, but has become rare in developed countries. Diagnosis is based on clinical manifestations combined with a history of severe PPH; hormone levels and/or stimulation tests can confirm clinical suspicion. Hormone replacement therapy is the only available management option so far.

Etiology of hypopituitarism in tertiary care institutions in Turkish population: analysis of 773 patients from Pituitary Study Group database

Hypopituitarism in adult life is commonly acquired and the main causes are known as pituitary tumors and/or their treatments. Since there are new insights into the etiology of hypopituitarism and presence of differences in various populations, more studies regarding causes of hypopituitarism are needed to be done in different ethnic groups with sufficient number of patients. Therefore, we performed a multi-center database study in Turkish population investigating the etiology of hypopituitarism in 773 patients in tertiary care institutions. The study was designed and coordinated by the Pituitary Study Group of SEMT (The Society of Endocrinology and Metabolism of Turkey). Nineteen tertiary reference centers (14 university hospitals and 5 training hospitals) from the different regions of Turkey participated in the study. It is a cross-sectional database study, and the data were recorded for 18 months. We mainly classified the causes of hypopituitarism as pituitary tumors (due to direct effects of the pituitary tumors and/or their treatments), extra-pituitary tumors and non-tumoral causes. Mean age of 773 patients (49.8 % male, 50.2 % female) was 43.9 ± 16.1 years (range 16-84 years). The most common etiology of pituitary dysfunction was due to non-tumoral causes (49.2 %) among all patients. However, when we analyze the causes according to gender, the most common etiology in males was pituitary tumors, but the most common etiology in females was non-tumoral causes. According to the subgroup analysis of the causes of hypopituitarism in all patients, the most common four causes of hypopituitarism which have frequencies over 10 % were as follows: non-secretory pituitary adenomas, Sheehan's syndrome, lactotroph adenomas and idiopathic. With regard to the type of hormonal deficiencies; FSH/LH deficiency was the most common hormonal deficit (84.9 % of the patients). In 33.8 % of the patients, 4 anterior pituitary hormone deficiencies (FSH/LH, ACTH, TSH, and GH) were present. Among all patients, the most frequent cause of hypopituitarism was non-secretory pituitary adenomas. However, in female patients, present study clearly demonstrates that Sheehan's syndrome is still one of the most important causes of hypopituitarism in Turkish population. Further, population-based prospective studies need to be done to understand the prevalence and incidence of the causes of hypopituitarism in different countries.

Four nephrology myths debunked

There are many controversial topics relating to renal disease in hospitalized patients. The aim of this review is to shed light on some important and often debated issues. Hypothyroidism, unlike myxedema, is not a cause of hyponatremia (although it can be sometimes seen in conjunction with the latter) and additional investigations should be done to determine its etiology. Sodium bicarbonate is effective for treatment of hyperkalemia primarily by enhancing renal potassium elimination rather than by translocating potassium into cells. Acetaminophen can be a cause of metabolic acidosis by causing 5-oxoprolinuria. Furosemide (and sulfa containing diuretics) can safely be used in patients with an allergy to sulfa-containing antibiotics (SCA).

Practice of symptomatic treatment in the era of evidence-based medicine: report of 2 cases of diagnosis of Sheehan's syndrome delayed till eighth decade

Sheehan's syndrome, first described in 1937, is characterised by postpartum haemorrhage, pituitary necrosis, lactational failure and hypopitutarism. Presentation is variable and late presentations are not unusual due to partial ischaemic injury of the pituitary and gradual loss of endocrine function. A history of postpartum haemorrhage is usual but in some cases it is not elicited. Presentations such as malaise, fatigue, hypoglycaemia, decline in cognition, hyponatraemia, pancytopoenia, osteoporosis, secondary infertility, confusion and coma have all been reported. Two interesting cases of Sheehan's syndrome are presented that were diagnosed in the eighth decade; one due to atypical presentation of recurrent hyponatraemia and confusion, another from hypoglycaemic coma and symptoms of malaise and lethargy.