Hypoglycemia

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Prehospital hypoglycemia: the safety of not transporting treated patients

OBJECTIVES

Emergency medical services (EMS) personnel frequently encounter patients who refuse transport after being treated for a hypoglycemic episode. The outcomes of most of these patients are unknown. The purpose of this study was to determine the outcomes of patients treated and not transported for hypoglycemia and identify criteria that could be used to identify patients who did not require transport to hospital.

METHODS

This was a prospective, observational study involving all adult (>15 years) hypoglycemic patients (blood glucose less than 4 mmol/L by glucometer) attended to by the EMS system in the Halifax Metropolitan area in the province of Nova Scotia during a ten-month interval.

RESULTS

There were 220 calls for adult patients with hypoglycemia. Of the 75 calls that resulted in transport, there were 17 further hypoglycemic episodes requiring a repeat call for an ambulance (22.7%) and three recurrences (4%). Of the 145 calls that did not result in transport, 40 further episodes of hypoglycemia (27.6%) and three recurrences (2%) were reported. These differences were not statistically significant (p=0.43 and 0.33, respectively). There was also no statistically significant difference in the intervals between hypoglycemic episodes for patients transported (51.1 days +/-65) compared with patients not transported for their previous hypogylcemic episode (40.7 days +/-53.5) (p=0.6). Of the 47 calls entered in the study, there were seven repeat calls for hypoglycemia (15%) and one recurrence (2.1%). The majority of patients did not follow up with their physician.

CONCLUSIONS

Repeat episodes of hypoglycemia are common; however, recurrences within 48 hours are not. Admission to hospital is rarely required. There appears to be no difference in the incidence of recurrences and repeat episodes of hypoglycemia between transported and nontransported insulin-dependent patients, regardless of age. Given the high incidence of repeat episodes, paramedics and physicians need to emphasize the importance of follow-up.

Treatment of patients who have type 1 diabetes mellitus: physiological misconceptions and infusion pump therapy

BACKGROUND

This article reviews the unique physiology of patients who have type 1 diabetes mellitus (insulin-dependent diabetes mellitus, or IDDM); allays some common physiological misconceptions; and updates dental practitioners on the emerging technology of insulin infusion pump therapy, now available to patients who have type 1 diabetes mellitus.

DESCRIPTION

The authors review the physiology of stress and describe the dawn phenomenon. They also describe insulin infusion pump therapy, as well as its advantages and disadvantages, to familiarize dentists with new technologies in caring for patients who have diabetes. Emergencies that may present themselves as a result of these advances in biotechnology are discussed.

CLINICAL IMPLICATIONS

Dental practitioners who treat patients who have IDDM need to have a solid foundation in the basic medical sciences and emerging biomedical technology as they each relate to diabetes. Practitioners must become familiar with infusion pump therapy, not only for cases of medical emergencies, but also to customize treatment for patients who have diabetes. Practitioners also need to remain up to date in the rapidly changing realm of caring for people who have diabetes.

Evaluation of patients admitted with hypoglycaemia to a teaching hospital in Central Anatolia

Hypoglycaemia is one of the most common endocrine emergencies in practice. We analysed retrospectively the incidence and causes of hypoglycaemia in patients admitted to Erciyes University Medical School in Turkey between January 1991 and June 1998 because of hypoglycaemia. Charts were reviewed according to multiple variables including age, sex, blood glucose levels, renal and liver functions, diagnoses, symptoms, drugs, complications, sequelae, and survival status. During this period, 13 500 patients were hospitalised and hypoglycaemia was reported in 126 (0.9%) patients. The most common causes were diabetic treatments in 54 cases (42%), endocrine deficiencies in 25 cases (20%), and malignancy in 15 cases (12%), respectively. The leading endocrine deficiency was panhypopituitarism. Sheehan's syndrome was the most common cause of panhypopituitarism (44%). No underlying cause was diagnosed in seven cases. Nine patients died (7%) and neurological sequelae were observed in one patient with diabetes mellitus. We conclude that hypoglycaemia accounts for about 1% of hospital admissions. Although the hypoglycaemia could be attributed to hypoglycaemic agents in the treatment of diabetes mellitus in the majority of cases, Sheehan's syndrome was also found to be an important cause of hypoglycaemia in our hospital.

Plasma glucose alone does not predict neurologic dysfunction in hypoglycemic nondiabetic subjects

STUDY OBJECTIVE

To assess the value of plasma glucose concentration alone as a predictor of neurologic dysfunction in nondiabetic subjects with normal baseline neurologic examination and electroencephalographic (EEG) findings.

METHODS

Neurologic function and EEG results were evaluated in 17 subjects before and during insulin-induced hypoglycemia using relevant and reliable clinical tools for bedside use.

RESULTS

Hypoglycemia (mean nadir concentration, 30 mg/dL) was without effect on level of consciousness or cranial nerve, motor, sensory, vestibulocerebellar, language, or simple visuospatial functions. Attention was minimally impaired in all subjects, but memory in only 3. EEG results remained normal in 5 subjects; minimal to moderate nonspecific changes occurred in the rest. All patients manifested signs of sympathetic stimulation from hypoglycemia, including tremor, tachycardia, and diaphoresis. The manifestations of neuroglycopenia did not correlate significantly with nadir plasma glucose or duration of hypoglycemia.

CONCLUSION

Moderately severe hypoglycemia of short duration can be neurologically occult, or subtle inattention can be its first and only clinical manifestation. Our findings are at variance with reports in the emergency medicine literature in which marked deficits are universally present at glucose concentrations equal to those attained in this study. This discrepancy suggests that the expression of neuroglycopenia is multifactorially determined and that plasma glucose concentration alone does not predict neurologic dysfunction in nondiabetic subjects with normal baseline neurologic examinations.

Dizziness: neurological emergencies

A patient's medical history provides the key information for deciding on the type of dizziness and its likely cause. First, one must separate vestibular from non-vestibular causes of dizziness to determine the focus of the diagnostic work-up. Of the common causes of vertigo, benign positional vertigo can be reliably diagnosed and cured at the bedside. One of the few instances where neuroimaging is required on an emergent basis is for a patient presenting with acute vertigo and profound imbalance likely to be a cerebellar hemorrhage or infarct. Antivertiginous and anti-emetic drugs can provide relief of acute vertigo and nausea, but medications should be rapidly tapered to allow compensation to occur.

Diabetes and the nervous system

Hyperglycemia and its vascular complications affect the entire nervous system, contributing to increased morbidity and mortality. Chronic hyperglycemia is not only a known and major risk factor for cerebral vascular diseases but also the presence of hyperglycemia at the time of a cerebrovascular event may adversely influence the outcome. It also affects the treatment of some neurodegenerative disorders, and there are suggestions that diabetes may in fact suffer from a "chronic diabetic encephalopathy." Its varied effects on the peripheral nervous system result in several forms of diabetic neuropathies, the exact pathogenesis of which is still obscure. There is, however, some new information that may link metabolic and vascular hypotheses.