Severe hypoglycemia in adults

Severe hypoglycemia is the most common endocrine emergency in adults. The diagnosis of severe hypoglycemia requires documentation of a low plasma glucose concentration, neuroglycopenic symptoms and reversal with the administration of glucose. The clinical features of severe hypoglycemia may be mistaken for an acute CNS event, sepsis or psychiatric disease. The most frequent causes of severe hypoglycemia in adults are insulin, sulfonylureas and ethanol. The most common underlying pathologic mechanism is increased insulin effect. The diagnostic approach to hypoglycemia in adults differs in patients who are well compared to those who are ill or hospitalized. Except in cases where the etiology is obvious, blood should be drawn for later measurement of insulin and C-peptide before hypoglycemia is corrected. Drug-induced hypoglycemia should be excluded, if possible, before embarking on the gold-standard test in the evaluation of fasting hypoglycemia in adults, the 48 hour supervised fast. Administration of glucose, either oral or parenteral, is the cornerstone of treatment of severe hypoglycemia. Glucagon is a less effective and only a temporary solution in most cases of severe hypoglycemia. Figure 1 shows an algorithm for the approach to severe hypoglycemia in adults. Education of the patient and close acquaintances is crucial to avoid recurrent and severe hypoglycemia in insulin-treated diabetes. Patients with frequent hypoglycemia should be counseled regarding driving precautions. Temporary cognitive dysfunction is an integral part of severe hypoglycemia, but permanent neurological impairment due to severe hypoglycemia in adults is rare.