Critical Care Glucose Point-of-Care Testing.

Maintaining blood glucose concentration within an acceptable range is a goal for patients with diabetes mellitus. Point-of-care glucose meters initially designed for home self-monitoring in patients with diabetes have been widely used in the hospital settings because of ease of use and quick reporting of blood glucose information. They are not only utilized for the general inpatient population but also for critically ill patients. Many factors affect the accuracy of point-of-care glucose testing, particularly in critical care settings. Inaccurate blood glucose information can result in unsafe insulin delivery which causes poor glucose control and can be fatal. Healthcare professionals should be aware of the limitations of point-of-care glucose testing. This chapter will first introduce glucose regulation in diabetes mellitus, hyperglycemia/hypoglycemia in the intensive care unit, importance of glucose control in critical care patients, and pathophysiological variables of critically ill patients that affect the accuracy of point-of-care glucose testing. Then, we will discuss currently available point-of-care glucose meters and preanalytical, analytical, and postanalytical sources of variation and error in point-of-care glucose testing.

The prevalence of significant left-right hip bone mineral density differences among black and white women.

SUMMARY: In a cross-sectional retrospective study, we examined the prevalence of significant opposite hip bone mineral density difference among white and black women. Left-right hip bone mineral density difference was a common finding in both races, raising the possibility that osteoporosis can be missed if only one hip is imaged. INTRODUCTION: We examined the prevalence of significant left-right hip bone mineral density (BMD) difference among black and white female subjects and its implications on the diagnosis of osteoporosis. METHODS: This was a retrospective review of dual energy X-ray absorptiometry (DXA) data in black and white subjects age 50 years and older. One thousand four hundred seventy-seven scans obtained using a GE Lunar Prodigy scanner in dual hip mode were analyzed (24% black, 76% white). Significant left-right hip BMD difference was considered present when the subregion least significant change (LSC) was exceeded. Its prevalence was determined, along with consequences on the diagnosis of osteoporosis. RESULTS: Significant differences in BMD were common in both races; the LSC was exceeded in 47% of the patients at the total hip, 37% at the femoral neck, and 53% at the trochanter. Diagnostic agreement was lower when the LSC was exceeded than when it was not. The LSC was exceeded in a statistically significant number of black and white patients with normal or osteopenic spines and unilateral hip osteoporosis. CONCLUSIONS: Significant left-right hip BMD difference is a common finding among black and white women and can result in osteoporosis being missed if only one hip is imaged.

A case of unilateral adrenal hyperplasia: the diagnostic dilemma of hyperaldosteronism.

OBJECTIVE: To report the successful laparoscopic surgical management of a case of right unilateral adrenal hyperplasia. METHODS: We present a case of unilateral adrenal hyperplasia and review the pertinent literature. The effectiveness of surgical treatment of unilateral adrenal hyperplasia is evaluated. RESULTS: A 50-year-old man had a 7-year history of hypertension, which had been treated with antihypertensive medications. On initial assessment, he was taking long-acting diltiazem, 240 mg twice a day, and his blood pressure was 150/84 mm Hg. He was noted to have recurrent hypokalemia, low plasma renin activity, increased plasma aldosterone concentration, and high urinary aldosterone levels. Magnetic resonance imaging of the adrenal glands revealed a normal left adrenal gland and fullness of the right adrenal gland. Selective adrenal vein catheterization showed findings consistent with a right-sided adrenal gradient. Surgical removal of the right adrenal gland laparoscopically alleviated his symptoms and cured his hypertension and hypokalemia. Pathologic examination of the right adrenal gland revealed diffuse hyperplasia of the zona fasciculata and zona reticularis. Plasma aldosterone, renin, and potassium levels returned to normal postoperatively, and his blood pressure declined to 120/70 mm Hg. At 1-year follow-up, the patient remained normotensive without the need for antihypertensive agents. CONCLUSIONS: This rare type of hyperaldosteronism, known as unilateral adrenal hyperplasia, is difficult to categorize not only because it fails to typify a conventional subtype but also because it is difficult to confirm the pathologic diagnosis. Recognition of the variety of provocative, biochemical, and imaging results that may be seen in this disorder is important in making the correct diagnosis. Determining unilaterality of disease by selective adrenal vein sampling can result in a cure of hypertension and hypokalemia by surgical resection.

Diagnosis and management of pheochromocytoma during pregnancy: a case report.

Pheochromocytoma is known to increase morbidity and mortality. We describe a case of pheochromocytoma during pregnancy. A patient was transferred to our hospital during gestational week 15 with severe hypertension, acute pulmonary edema, and cardiomyopathy. One day after transfer, she had a spontaneous abortion of the fetus. One week after hospital transfer, she developed acute dyspnea, supraventricular tachycardia degenerating into ventricular tachycardia, and respiratory failure requiring mechanical ventilation. Pheochromocytoma caused by a right adrenal mass was diagnosed. The patient was treated with titrated doses of phenoxybenzamine, intravenous nicardipine, and metyrosine over a period of 3 weeks with resultant stabilization of her blood pressure. She underwent a successful right adrenalectomy 1 month after her initial presentation. Four months after surgery, all antihypertensive medications were discontinued and her blood pressure remained stable 1 year after the surgery. This case describes the maternal morbidity and fetal mortality that may be associated with pheochromocytoma during pregnancy.

Physician office-based diabetes care: comparison to guidelines for care.

Over the past decade, we have seen a significant increase in hospitalizations in South Carolina for the major complications of diabetes: myocardial infarcts (+68 percent), amputations (+61 percent), end stage renal disease (+85 percent), diseases of blood vessels (+100 percent), and eye complications (+52 percent). Many of these late stage complications can be prevented or their progression slowed down by early recognition and institution of intensive, well-defined preventive strategies. Independent surveys reviewed above indicate that such preventive practices are not being fully utilized in South Carolina. As one key example, less than 50 percent of people with diabetes receive self-management education. A number of simple and relatively inexpensive laboratory and physical examinations which would trigger preventive and remedial therapy are also performed at less than adequate frequency. The challenge is for all to use these examinations to guide therapy and to continue to monitor and intervene to prevent complications of diabetes. The DSC Board of South Carolina has developed a Ten Year Strategic Plan with nine major goals to improve diabetes care and outcomes in South Carolina. To improve office-based care of diabetes in South Carolina, all health professionals must assume responsibility for closely monitoring each person with diagnosed diabetes and assure that glycemic control is optimized. Early signs of complications must be recognized and interventions to limit their progression utilized. Screening of high-risk individuals to identify the estimated one-third of persons with diabetes who are undiagnosed, targeted education programs to the primary care professionals who deliver the majority of care to individuals with diabetes, implementation of the proven, cost-effective measures that can prevent (postpone) the complications of diabetes, monitoring of the health care delivery system and addressing the potential barriers to adequate care for all persons with diabetes are essential steps to decrease the burden of diabetes for South Carolinians (Table 1).

Diabetes research in South Carolina: past, present, and future.

Medical investigators in South Carolina have been on the "cutting edge" of diabetes research for a number of decades. Despite this fact, our state ranks second in the nation in diabetes prevalence, and diabetes complications are more severe here than anywhere else. It is from the efforts of these investigators that our hope for a brighter future comes. Through a concerted effort toward prevention, improvements in care, and investigation of the pathophysiology of diabetes and its complications, researchers may reduce the substantial burden of diabetes in our state and throughout the world.

Clinical implications of the insulin resistance syndrome.

Insulin resistance syndrome (IRS), also termed syndrome X, is a distinctive constellation of risk factors for the development of type 2 diabetes mellitus and cardiovascular disease. The syndrome's hallmarks are glucose intolerance, hyperinsulinemia, a characteristic dyslipidemia (high triglycerides; low high-density lipoprotein cholesterol, and small, dense low-density lipoprotein cholesterol), obesity, upper-body fat distribution, hypertension, and increased prothrombotic and antifibrinolytic factors. Insulin resistance, caused by a complex of genetic and environmental influences, is now recognized not just as a mechanism contributing to hyperglycemia in type 2 diabetes, but also as an early metabolic abnormality that precedes the development of overt diabetes. The clinical definition of insulin resistance is the impaired ability of insulin (either endogenous or exogenous) to lower blood glucose. In some insulin-resistant individuals, insulin secretion will begin to deteriorate under chronic stress (glucose toxicity) and overt diabetes will result. If not, individuals will remain hyperinsulinemic, with perhaps some degree of glucose intolerance, together with other hallmarks of the IRS. The statistical correlation between hypertension and impaired glucose tolerance is clear, although the mechanism is not yet fully understood. Epidemiologic evidence of insulin resistance as an independent risk factor for atherosclerosis and coronary heart disease (CHD) completed the evolving concept of IRS as the common soil for the development of both diabetes and CHD. No single laboratory test exists for diagnosis of IRS. Rather, IRS remains a clinically evident syndrome that can be suspected on the basis of physical and laboratory findings. This identifies individual patients whom the clinician should screen for associated comorbid conditions, aggressively control cardiovascular risk factors, and tailor drug therapy for optimal benefit. This article provides practical guidelines to achieve these goals and specific strategies to ameliorate cardiovascular and metabolic risk in the IRS.

LDL from patients with well-controlled IDDM is not more susceptible to in vitro oxidation.

Increased susceptibility of LDL to oxidation has been shown to be associated with the presence of coronary heart disease and may account for the accelerated vascular disease seen in diabetes. The response of LDL to in vitro oxidative stress has been proposed as a measure of the predisposition of LDL to the in vivo subendothelial oxidative stress. Increased susceptibility to oxidation has been demonstrated recently in diabetic patients with poorly controlled IDDM. Thus, we conducted studies to determine whether the increased susceptibility of LDL to oxidation was secondary to diabetes per se or to the level of glycemic control. Fifteen IDDM patients with good glycemic control and with no evidence of macrovascular disease or proteinuria were compared with healthy age-, sex-, race-, and BMI-matched nondiabetic subjects. Fasting blood glucose levels averaged 12.1 +/- 1.1 (mean +/- SE) vs. 4.9 +/- 0.1 mmol/l in the diabetic versus the control groups, respectively. HbA1c levels averaged 7.7 +/- 0.5 vs. 4.4 +/- 0.2%, reflecting well-controlled diabetes (P < 0.0001). Total, LDL, VLDL, and HDL cholesterol, triglyceride, and lipoprotein(a) levels did not differ between the groups. The particle size, lipid composition, fatty acid content, antioxidant content, and glycation were similar for LDL isolated from both groups. A rapid LDL preparation technique was used to compare LDL susceptibility to oxidation under the following conditions: final LDL cholesterol concentration of 100 microg/ml, 5 micromol/l of CuCl2 at 25 degrees C. There was no difference in the susceptibility to in vitro oxidation of LDL isolated from IDDM patients compared with control subjects. There was no correlation of glycemic control with any of the parameters of the in vitro oxidation of LDL. LDL from patients with well-controlled IDDM does not differ in composition or in susceptibility to in vitro oxidative stress compared with LDL from nondiabetic subjects.