Water, Electrolytes, and Carbohydrates

Which stationary phase is used for the measurement of hemoglobin A1c by high performance liquid chromatography?

Cation exchanger

Which of the following conditions is associated with hypernatremia?

Diabetes insipidus

Which of the following conditions is most likely to produce an elevated plasma potassium?

Digitalis overdose

Which of the following conditions is associated with hyponatremia?

Diuretic therapy

In addition to measuring blood glucose, Hgb A1c, and microalbumin, which test should be done on diabetic persons once per year?

Estimated glomerular filtration rate

Given the following serum data, determine the anion gap: Na = 132 mmol/L Cl = 90 mmol/L HCO3- = 22 mmol/L

(132) - (22 + 90) = 20 mmol/L

What is the formula for calculating an anion gap?

(Na+) - (CO2 + Cl-) = 12 (Range of 8 - 16) Anions could also include HCO3-

According to American Diabetes Association criteria, which result is consistent with a diagnosis of impaired fasting glucose?

117 mg/dL

Which of the following 2-hour glucose challenge results would be classified as impaired glucose tolerance (IGT)?

150 mg/dL

Which of the following values is the threshold critical value (alert or action level) for high plasma sodium?

160 mmol/L

Which formula is most accurate in predicting plasma osmolality?

2(Na) + (glucose / 18) + (BUN / 2.8) +9

Which of the following values is the threshold critical value (alert or action level) for low plasma potassium?

2.5 mmol/L

What is the American Diabetes Association recommended cutoff value for adequate control of blood glucose in diabetes as measured by glycated hemoglobin?

6.5%

Select the most appropriate adult reference range for fasting blood glucose.

65-99 mg/dL (3.61-5.50 mmol/L)

Which of the following conditions is associated with hypokalemia?

Alkalosis

Point-of-care-tests (POCTs) for whole-blood glucose monitoring are based mainly on the use of __________.

Amperometric detection

Which electrolyte measurement is least affected by hemolysis?

Calcium

When preparing a patient for an oral glucose tolerance test (OGTT), which of the following conditions will lead to erroneous results?

Carbohydrate intake is restricted to below 150 g/day for 3 days prior to test

Which testing situation is appropriate for the use of point-of-care whole-blood glucose methods?

Monitoring of blood glucose control in type 1 and type 2 diabetics

Which of the following findings is characteristic of all forms of clinical hypoglycemia?

Neuroglycopenic symptoms at the time of low blood sugar

What is the osmolal gap?

Osmolal gap = measured osmolality - calculated osmolality

Which of the following conditions is associated with low serum magnesium?

Pancreatitis

In peroxidase-coupled glucose methods, which reagent complexes with the chromogen?

Phenol

Which of the following results fall within he diagnostic criteria for diabetes mellitus?

Random plasma glucose of 250 mg/dL and presence of symptoms

Which statement regarding glyctaed (glycosylated) Hgb (G-Hgb) is true?

Reflects the extent of glucose regulation in the 8 to 12 week interval prior to sampling

Which of the following conditions is associated with total body sodium excess?

Renal failure

Which of the following conditions will cause an increased anion gap?

Renal failure

Which of the following is characteristic of type 1 diabetes mellitus?

Requires insulin replacement to prevent ketosis

Which electrolyte is least likely to be elevated in renal failure?

Sodium

Which electrolyte level best correlates with plasma osmolality?

Sodium

Which of the following is the primary mechanism for vasopressin (ADH) release?

Hyperosmolar plasma

Which of the following conditions involving electrolytes is described correctly?

Hypoalbuminemia causes low total calcium but does not affect Ca i

Which statement regarding gestational diabetes mellitus (GDM) is correct?

Is defined as glucose intolerance originating during pregnancy

Which statement about glucose in cerebrospinal fluid (CSF) is correct?

Levels below 40 mg/dL occur in septic meningitis, cancer, and multiple sclerosis

Which statement regarding measurement of Hgb A1c is true?

Levels do not need to be done fasting

What effect does hematocrit have on POCT tests for whole-blood glucose monitoring?

Low hematocrit raises readings and high hematocrit lowers readings unless corrected

Which statement best describes the use of the Hgb A1c test?

May be used for both diagnosis and monitoring

In which condition would hypochloremia be expected?

Metabolic alkalosis

Which glucose method is subject to falsely low results caused by ascorbate?

Trinder glucose oxidase

Which of the following biochemical processes is promoted by insulin?

Uptake of glucose by cells

Which of the following is characteristic of type 2 diabetes mellitus?

Hyperglycemia is often controlled without insulin replacement

Select the enzyme that is most specific for Beta-D-glucose.

Glucose oxidase

Select the coupling enzyme used in the hexokinase method for glucose.

Glucose-6-phosphate dehydrogenase

Which of the following hormones promotes hyperglycemia?

Growth hormone

Which of the following is a potential source of error in the hexokinase method?

Hemolysis

Which of the following is the reference method for measuring serum glucose?

Hexokinase