Acid Base, Blood gases and Electrolytes
Potassium, Magnesium, Iron, Total Protein
(Serum iron/TIBC) X 100
Patients who develop severe sepsis or septic shock commonly have __________ plasma lactate values.
Increased
When a patient is suspected of intoxication, what would you expect the osmol gap to be?
Increased
What would you expect the serum iron (SI) and total iron binding capacity (TIBC) to be in a person with hereditary hemochromatosis (HH)?
Increased SI and decreased TIBC
Respiratory acidosis is associated with:
Increased pCO2
When evaluating a patient for a suspected Wilson's Disease diagnosis, low values of plasma ceruloplasmin would be expected along with:
Increased urine copper
When iontophoresis is used to collect sweat for chloride analysis, pilocarpine is used to:
Induce the sweat secretion
Which one of the following is the correct definition of isoelectric point (pI)?
The pH where a molecule has a net charge of zero
Which of the following conditions should be suspected if a healthy patient presents with an elevated potassium level while all other chemistry results are normal?
The sample is hemolyzed
A serum specimen for potassium testing is collected in a red top tube without a gel separator barrier. If testing is delayed by a few hours, how should the specimen be handled?
The specimen should be centrifuged as soon as it clotted and serum should be transferred to another tube.
Which of the following is the most common cause of hyperkalemia in hospitalized patients?
Therapeutic potassium replacement
pH alteration of normal blood in a closed vessel standing at 37oC for 1 hour is approximately:
0.04 to 0.08 pH units
Which of the following additives should be used for the collection of a sample for blood gas analysis?
Heparin
A specimen for potassium was drawn in a tube without anticoagulant at 6 AM during a traumatic patient stick. The results were 6.0 mmol/L. Why are the results elevated?
Hemolysis of the RBC's
A patient has the following serum results: Na = 130 mEq/LK = 4.9 mEq/LCl = 107 mEq/LGlucose = 300 mg/dLBUN = 18 mg/dLCreatinine = 1.1 mg/dL Which osmolality result is consistent with these results?. Note: There are various published versions of this particular equation that will produce slightly different results (choose the value closest to your calculated result).
281 mosmol/kg
What percentage of dietary iron is normally absorbed daily?
5% to 15%
A patient's electrolyte results are the following: Sodium = 145 mmol/L Chloride = 113 mmol/L Bicarbonate = 24 mmol/L Calculate the anion gap for this patient and choose the correct answer below.
8 mmol/L
Select the equation which is used to determine the pH of a solution containing a weak acid and its salt.
Henderson-Hasselbalch equation
Which of the following patients is most at risk for hyperosmolar nonketotic coma?
A 70-year-old type 2 diabetic patient
When the body compensates for a respiratory or metabolic disorder, the MAIN goal is to achieve:
A normal pH
What is the cause of iron overload in hereditary hemochromatosis?
Absorption of excessive amounts of iron in the small intestine
Ion selective electrodes, for pH determinations, are called selective rather than specific because they actually measure the:
Activity of one ion much more than other ions present
What is the term used to describe cardiac tissue death due to lack of oxygen caused by obstruction of circulation?
Acute myocardial infarction (AMI)
The Emergency Department has collected blood test tubes for potassium, albumin, plasma hemoglobin, and acid phosphatase. Which of these test results will NOT be negatively affected if the blood tube is sent by the hospital's pneumatic tube system?
Albumin
A Comprehensive Metabolic Panel (CMP) consists of which group of tests?
Albumin, Glucose, BUN, Creatinine, Sodium, Potassium, Chloride, CO2, AST, ALT, Alkaline Phosphatase, Total Protein, Total Bilirubin, Calcium
An automated method for measuring chloride which generates silver ions in the reaction is called:
Amperiometric-coulometric titration
What is the term used to describe chest pain caused by inadequate supply of oxygen to heart myocardium?
Angina
MOST of the carbon dioxide present in the blood is in the form of:
Bicarbonate
Carbon dioxide is predominately found in blood in the form of:
Bicarbonate ions
Blood lactate concentration is an indicator of impaired circulation and tissue oxygenation in critically ill patients. If circulation and tissue oxygenation are impaired:
Blood lactate concentration will increase.
8-Hydroxyquinoline and Ortho-Cresolphthalein complexone (CPC) reagent is commonly used in the determination of:
Calcium
The parathyroid hormone (PTH) is important in the regulation of:
Calcium and phosphate
Ionized calcium is currently most commonly measured using which of the following method?
Calcium ion selective electrodes
In blood, bicarbonate leaves the red blood cell and enters the plasma through an exchange mechanism with:
Chloride
The buffering capacity of blood is maintained by a reversible exchange process between bicarbonate and:
Chloride
All of the following tests are part of the Electrolyte Panel, EXCEPT?
Cholesterol
What is the term used to describe a clinical syndrome caused by heart disease, represented by abnormal sodium and water retention and breathlessness, usually resulting in edema?
Congestive heart failure (CHF)
Iontophoresis is a technique used in the diagnosis of:
Cystic fibrosis
The measurement of sodium and chloride in sweat is the most useful test for the diagnosis of what condition/disease?
Cystic fibrosis
What changes in potassium and sodium serum results may occur with diuretic use?
Decrease in both.
Which of the following sets of results is indicative of stage 3 iron deficiency (iron deficiency anemia)?
Decreased ferritin, increased sTfR, increased TIBC
Zinc deficiency in the elderly is often caused by:
Decreased intake and absorption
What are the expected results of the laboratory markers in iron deficiency anemia?
Decreased serum iron, increased transferrin, decreased ferritin, decreased percent saturation, and increased total iron binding capacity.
In which of the following condition(s) would an increased serum osmolality be an expected finding?
Dehydration and Diabetes insipidus
What drug may be used to decrease iron levels in patients with iron overload?
Desferrioxamine
Which values would be expected with metabolic alkalosis?
Elevated pH, increased bicarbonate, normal PCO2
Which of the following would you find in a primary hyperparathyroidism case?
Elevated serum calcium and decreased serum phosphorus
Which of the following is a cause of metabolic alkalosis?
Excessive vomiting
Which of the following will give the best overall picture of a patient's iron stores:
Ferritin
Which of the following are terms used to describe storage pool iron?
Ferritin and hemosiderin
Which of the following forms of calcium is biologically active:
Free ionized calcium
Hydrogen ion concentration (pH) in blood is usually determined by means of which of the following electrodes?
Glass
A Basic Metabolic Panel (BMP) consists of which group of tests?
Glucose, BUN, Creatinine, Sodium, Potassium, Chloride, CO2, Calcium
A Renal Function Panel consists of which of the following tests?
Glucose, BUN, Creatinine, Sodium, Potassium, Chloride, CO2, Calcium, Albumin, Phosphorus
The most likely cause of an elevated serum potassium level in an apparently normal individual is:
Hemolysis
All of the following anticoagulants will produce a significant effect on calcium levels in plasma, EXCEPT?
Heparin
A 56-year old female was taken to the emergency room in a coma by her employer's nurse. She had lost 35 pounds in 3 months; she was always thirsty; drinking a lot of water and running to the bathroom. The following are her laboratory results: Results: (indicates reference range) pH: 7.11 (7.35-7.45)pCO2: 21 mm Hg (35-45 mm Hg)Glucose: 950 mg/dL (60-110 mg/dL)Serum osmolality: 365 mOsm/Kg (275-295 mOsm/Kg)Urine ketone: strongly positive (negative)Urine glucose: strongly positive (negative) What is the MOST likely cause of this patient's symptoms?
Insulin dependent diabetes mellitus
Which one of the following statements about serum ferritin is true
It is a sensitive indicator of iron deficiency
All of the following are causes of hypernatremia EXCEPT:
Low aldosterone production
Metabolic acidosis is characterized by:
Low pH
Which of the following would most likely occur as the result of hemodilution?
Low serum electrolyte values
All of the following would be considered a normal part of a routine electrolyte panel (profile), EXCEPT?
Magnesium
A 46-year-old woman was admitted to the hospital through the emergency room after having a bout of severe diarrhea for 3 days along with headaches, muscle aches, shortness of breath, and an increased heart rate. Blood gas measurements were ordered by her concerned physician. The results showed the following: pH = 7.30 pCO2 = 32 mm HgHCO3- = 15 mmol/L pO2 = 93 mmol/L What acid base disorder is most consistent with this patient's results and symptoms?
Metabolic acidosis
The following results were obtained on arterial blood: pH = 7.51pCO2= 49 mm HgHCO3- = 38.7 mmol/LpO2= 85 mm Hg These results are compatible with:
Metabolic alkalosis
What is the term used to describe inadequate blood supply that decreases availability of oxygen to the myocardium?
Myocardial ischemia
Which statement best describes the relationship between dietary iron and iron absorption in a healthy individual?
Only a small percentage of dietary iron is absorbed and used.
Which three hormones are known to regulate serum Ca2+ by changing their secretion rate in response to changes in ionized Ca2+?
PTH, vitamin D & calcitonin
Which of the following is considered a cause of hypomagnesemia (decreased levels of magnesium in the blood)?
Pancreatitis
A liquid ion-exchange membrane electrode using the antibiotic valinomycin is MOST selective for:
Potassium
The presence of only slightly visible hemolysis will significantly increase the serum level of which of the following electrolytes?
Potassium
Which of the following electrolytes is most likely to be spuriously elevated in a hemolyzed specimen?
Potassium
Which of the following analytes will be falsely increased due to hemolysis?
Potassium, Magnesium, Iron, Total Protein
An electrolyte panel (lytes, chem-4) consists of:
Potassium, Sodium, Chloride, Carbon dioxide (in form of bicarbonate)
It is important to specify if a blood specimen is a capillary specimen rather than a venous specimen. How will the following laboratory results be affected if a capillary specimen is tested?
Potassium, calcium, and total protein are lower in capillary specimens, where glucose is typically higher than in venous blood.
The selectivity of an ion-selective electrode is determined by the:
Properties of the membrane used
Which of the following contributes to specific gravity but does NOT contribute to osmolality?
Protein
You are processing specimens for your laboratory when you receive a potassium test specimen in a tube that looks like the one in the image. What should you do?
Reject the specimen, the potassium test results will be increased.
A three-year-old boy was brought unconscious to the emergency room. Arterial blood gas results were as follows: pH = 7.07pCO2 = 90 mm HgHCO3- = 23 mmol/L This patient is most likely suffering from:
Respiratory acidosis
A young man is experiencing difficult breathing after fainting. The physician orders an arterial blood gas analysis which shows the following results: pH = 7.25 pCO2 = 62 mmHg pO2 = 70 mmHg HCO3- = 23 mmol/L Which condition is most likely afflicting this patient?
Respiratory acidosis
All of the following analytes would be significantly increased in a plasma sample as a result of hemolysis, EXCEPT?
Sodium
Which of the following contributes most to serum osmolality:
Sodium
An electrolyte panel is composed of which of the following tests?
Sodium, potassium, chloride, CO2
In healthy individuals, calcitonin is synthesized by which cells in the body?
Thyroid C cells
Total iron-binding capacity measures the serum iron transporting capacity of:
Transferrin
What condition is indicated by the following arterial blood gas results? Bicarbonate = 32 mmol/L (Normal = 22 - 29 mmol/L) pCO2 = 65 mm Hg (Normal = 35 - 45 mmHg) pH = 7.28 (normal = 7.35 - 7.45)
Uncompensated respiratory acidosis
All of the following variables related to the collection of blood may falsely increase the potassium level EXCEPT?
Using a 21 G needle with a 10 mL collection tube.
A hospitalized patient has a decreased serum copper level and increased urine copper level. This is MOST consistent with:
Wilson's disease
Which of the following statements is TRUE with respect to uncompensated metabolic alkalosis?
pH will be elevated without an elevation of pCO2
Which of the following is TRUE of a fully compensated metabolic acidosis?
pH will be normal with a decrease in pCO2