Lab Values and Diagnostic tests
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what is ur blood urea nitrogen and indication of?
indirect and rough measurement of renal function and glomerular filtration rate (if normal liver function exists).
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what is a critical blood urea nitrogen (BUN) value?
>100 mg/dL (indicates serious imparement of renal function)
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measures the amount of urea nitrogen in the blood
blood urea nitrogen (BUN)
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this is formed in the liver as the end product of prptein metabolism and digestion. amonia molecules are combined (formed fro broken down amino acids) to form this
urea
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patients whp have elevated BUN levels are said to have...
azotemia
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refers to elevation of the BUN as a result of pathologic conditions that affect urea nitrogen accumulation before it gets to the kidney
prerenal azotemia
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what are some examples of prerenal azotemia
shock, dehydration, congestive heart failure, and excessive protein catabolism, gi bleeding that causes blood in intestinal tract
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refers to pathologic conditions that affect urea nitrogen accumulation after it gets to the kidney
postrenal azotemia
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patients with severe primary liver disease will have a (increased/decreased) BUN
decreased
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low protein diets will (increase/decrease) BUN if caloric intake is maintained with carbohydrates
decrease
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critical blood CO2 level
<10 mEq/L or >40 mEq/L
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what is blood CO2 an indication of?
peripheral venous blood this is used to assist in evaluating the pH status of the patient and to assist in evaluation of electrolytes
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what does blood CO2 measure?
H2CO3, dissolved CO2 and the bicarbonate ion (HCO3
−) that exists in the serum
−) that exists in the serum
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what are levels of HCO3- regulated by
the kidneys
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an increase HCO3- occurs with _______ and a decrease occurs with ___________
alkalosis; acidosis
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critical cloride blood value
<80 or >115 mEq/L
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indications for chlorideblood tests?
test does not provide much information. However, with interpretation of the other electrolytes, chloride can give an indication of acid–base balance and hydration status
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excessive infusions of saline solutions can result in (increase/decrease) chloride levels
increase
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what is a critical blood creatine level
>4 mg/dL
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what is creatine an indication forsed to diagnose
blood creatine is used to diagnose impaired renal function
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what is creatinine?
a catabolic product of cre-atine phosphate, which is used in skeletal muscle contraction
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what is creatinine excreeted by?
the kidneys
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glucose levels are ____ in a fasting state; in response; glucagon is secreted which breaks glycogen down to glucose in the liver and glucose levels rise
low
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critical blood potasium in adults
<3 or >6.1 mEq/L
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what is potasium excreted by
kidneys
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aldosterone and to a lesser extent glucocorticosteroids (increase/decrease) renal loss of potasium
increase
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if sodium is reabsorbed potassium is (gained/lost)
lost
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alkalotic states tend to (increase/lower) serum potassium lvels by causing a shift of potassium into the cell. Acidotic states tend to (increase/lower) serum potasium levels by reverting the shift
lower; increase
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what are symptoms of hyperkalemia?
irritability, nausea, vomiting, intestinal colic, and diarrhea.
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what are signs of hypokalemia
decrease in contractility of smooth, skeletal, and cardiac muscles, which results in weakness, paralysis, hyporeflexia, ileus, increased cardiac sensi-tivity to digoxin, cardiac arrhythmias (dysrhythmias), flattened T waves, and prominent U waves.
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the opening and closing of the hand with a tourniquet in place may (increase/decrease) blood potassium levels
increase
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hemolysis of blood during venipuncture of during lab processing cases (increased/decreased) blood potasium levels
increased
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critical blood sodium levels
<120 or >160 mEq/L
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what is the reason for performing a blood sodium levels test?
This test is used to evaluate and monitor fluid and electrolyte balance and therapy (routine part of metabolic pannel)
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this is the major determinat of extracellular osmality of your cells
sodium salts
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as free body water is increased, serum sodium is _____ and the concentration may decrease; kidneys compensate bu conserving sodium and excreting water
diluted
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symptoms of hypernatremia
dry mucous membranes, thirst, agitation, restlessness, hyperreflexia, mania, and convulsions
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normal male hematocrit
42%–52% or 0.42–0.52 volume fraction (SI units)
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normal female hematocrit (non pregnant)
37%–47% or 0.37–0.47 volume fraction (SI units)
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pregnant female hematocrit
>33%
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critical hematocrit value
<21% or >65%
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indirect measurement of red blood cell (RBC) number and volume
hematocrit (Hct)
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what is Hct used for?
a rapid measurement of RBC count. It is repeated serially in patients with ongoing bleeding or as a routine part of the complete blood cell count. It is an integral part of the evaluation of anemic patients
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decreased Hct values indicate _______- (reduced number of RBCs) increased levels indicate __________
anemia; erythrocytosis
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larger RBCs are associated with higher _____________ because the larger RBCs take up greater percentage of total blood volume
Hct Levels
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extreamely elevated _______ decrease Hct which would falsy indicate anemia
WBCs
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livcing in high altitudes causes (increased/decreased) Hct values as a result of a physilogical response to the decreased oxygen availability
increased
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normal male hemoglobin
14–18 g/dL or 8.7–11.2 mmol/L (SI units)
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normal female hemoglobin
12–16 g/dL or 7.4–9.9 mmol/L
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pregnant female hemoglobin
>11 g/dL
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what are critical hemoglobin values
<7 g/dL or >21 g/dL
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This test is a measure of the total amount of Hgb in the blood. It is used as a rapid indirect measurement of the red blood cell (RBC) count. It is repeated serially in patients with ongoing bleeding or as a routine part of the complete blood cell count (CBC). It is an integral part of the evaluation of anemic patients
blood hemoglobin
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The Hct in percanage points is usually three times the ______ concentration in grams per decileter
Hgb
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what is Hgb made up of?
f heme (iron surrounded by protoporphyrin) and globin consisting of an alpha-and a beta-polypeptide chain.
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abnormalities of the globin structre of hgb
hemoglobinopathies
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When Hgb levels are too high because of increased numbers of RBCs_________________, leading to stroke and other organ infarction.
intravasculatr sludging
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when would a blood transfusion be reccomened (based on Hgb) in individuals of younger age? older age?
Hgb level 6 g/dL; Hgb level <10 g/dL
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heavy smokers have (higher/lower) Hgb levels than non smokers
higher
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critical platelet count numbers
<20,000 or >1 million
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an actual count of the number of platelets (thrombocytes) per cubic milliliter of blood. It is performed on patients who develop petechiae (small hemorrhages in the skin), spontaneous bleeding, increasingly heavy menses, or thrombocytopenia. It is used to monitor the course of the dis-ease or therapy for thrombocytopenia or bone marrow failure.
blood platelet count
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what forms platelets
megakaryocytes in the bone marrow
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the primary phase of ______ involves platelet aggregation; from here platelets help initiate the cpagulation gactor cascade
hemostatic mechanism
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where do platelets exist?
mostly in the blood; 25% in the spleen
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low platelet count name
thrombocytopenia;
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high blood p;latelet count
thrombocytosis
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diseases asspociated with spontaneous thrombocytosis
n deficiency anemia and malignancy (leukemia, lymphoma, solid tumors such as of the colon); polycythemia vera, postsplenectomy syndromes, and a variety of acute/chronic infections or inflammatory processes.
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spontaneous _____ may occur with thrombocytopenia
hemorage
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these (x2) can occur with severe degrees of thrombocytopenia (below 20,000 mm^3)
petechia and ecchymosis
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normal male RBC count
4.7-6.1 RBC × 106/μL or RBC × 1012/L [SI units]
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normal female RBC counts
4.2-5.4 RBC × 106/μL or RBC × 1012/L [SI units]
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closely related to the hemoglobin (p. 265) and hematocrit (p. 261) levels and rep-resents different ways of evaluating the number of RBCs in the peripheral blood. It is repeated serially in patients with ongoing bleeding or as a routine part of the complete blood cell count. It is an integral part of the evaluation of anemic patients.
RBC count
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count of the number of circulating RBCs in 1 mm3 of peripheral venous blood
RBC count
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what produces RBCs
erythroid elements in bone marrow
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this increases RBC production
erythropoietin
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what makes up the red blood cell indices
mean corpusular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red blood cell distribution width (RDW)
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provide information about the size (MCV and RDW), hemoglobin content (MCH), and hemoglobin concentration (MCHC) of RBCs. This test is useful in classifying anemias
red blood cell indices
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cdll size (when descrobing anemias) is described as (x3)
“normocytic,” “microcytic,” and “macrocytic.”
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hemoglobin content (when catagorizing anemias) is described as (x3)
“normochromic,” “hypochromic,” and “hyperchromic.”
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measure of the average volume, or size, of a single RBC and is therefore used in classifying anemias.
mean corpuscular volume
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MCH eauqtion
hemoglobin/ RBC 
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measure of the average amount of hemoglobin within an RBC
mean corpuscular hemoglobin
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a measure of the average concentration or percentage of hemoglobin within a single RBC.
mean corpuscular hemoglobin concentration
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MCHC equation
hemoglobin/hematocrit percentage
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indication of the variation in RBC size. It is calculated by a machine using the MCV and RBC values
red blood cell distribution width
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total adult WBC count normal
Adult/child > 2 years: 5000–10,000/mm3 or 5–10 × 109/L (SI units)
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critical value WBC count
<200 or >40,000 mm^3
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measurement of the total and differential WBC count is a part of all routine laboratory diagnostic evaluations. It is especially helpful in the evaluation of the patient with infection, neoplasm, allergy, or immunosuppression
WBC counts
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An increase in the percentage of one type of leukocyte mean a (increase/decrease) in the percentage of another
decrease
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these make uo most of the total leukocutes
neutrophyls and lymphocytes
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what does an increased WBC count indicate
infection, in-flammation, tissue necrosis, or leukemic neoplasia
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trauma or stress can (increase/decrease) WBC counts
increase
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WBC count <4000
leukopenia
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when does leukopenia occur
forms of bone marrow failure
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which white blood cells are granulocytes
neutrophyls, basophils, eosinophils
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what makes up nongranulocytes
lymphocytes and monocytes
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a screening marker indicating increased risk for birth defects, such as fetal body wall defects, neural tube defects, and chromosomal abnormalities. It can also be used as a tumor marker to identify cancers.
alpha fetoprotein
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AFP is an effective screening serum marker for these defects
fetal body wall; neural tube defects
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what does a normal karyotyping consit of?
a pattern of 22 pairs of autosomal chromosomes and a pair of sex chromosomes: XY for the male and XX for the female.
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test is used to diagnose pregnancy. It is also helpful in monitoring high-risk pregnancies. It can be used as a tumor marker for hCG-producing cancers.
HCG test
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The measurement of the ratio of the lipids L/S ratio has emerged as the standard criterion test to evaluate fetal lung maturity.
Lecithin and sphingomyelin (L/S ratio).
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This is a minor component (about 10%) of lung surfactant phospho-lipids and therefore, alone, is less accurate in measuring pulmonary maturity. However, because PG is synthesized almost entirely by mature lung alveolar cells, it is a good indicator of lung maturity. (amniocentesis)
phosphatidylaglycerol (PG)
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How is a woman's obstetric history written out?
G (number of pregnancies) P t-p-a-l
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what is t in G P tpal
term pregnancies (37-42wks)
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what is p in G P tpal
preterm pregnancies (20 to <37wks)
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what is a in G P tpal
spontaneous or induced abortionsand ectopic pregnancies
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what is l in G P tpal
live children
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what does this show
apgar score table
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assists in the evaluation of patients with acid–base disorders. It is used to attempt to identify the potential cause of the disorder and can also be used to monitor therapy for acid–base abnormalities
anion gap
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anion gap equation
AG = [sodium + potassium] − [chloride + bicarbonate]
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This calculation (anion gap) is most often helpful in identifying the cause of ___________. As acids such
as lactic acid or ketoacids accumulate in the bloodstream,
as lactic acid or ketoacids accumulate in the bloodstream,
metabolic acidosis
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As albumin (usually negatively charged) __________, AG will increase. In the face of normal albumin, a high AG is usually a result of an increase in non–chloride-containing acids or organic acids (such as lactic acid or ketoacids)
increases
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reased AG is very rare but can occur when there is an increase (x2)
unmeasured calcium or magnesium cations
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An increased AG, despite a normal pH, will indicate an ________ component to the metabolic picture.
acidotic
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this may cause under measurement of sodium and therefore falsly decrease Anion gap
hyperlipidemia
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provides valuable information in assessing and managing a patient’s respiratory (ventilation) and metabolic (renal) acid–base and electrolyte homeostasis. It is also used to assess the adequacy of oxygenation
arterial blood gasses (ABGs)
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Therefore, as the hydrogen ion concentration decreases, the pH __________
increases
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acids normally found in the blood (x4)
carbonic acid (H2CO3), dietary acids, lactic acid, and ketoacids
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a measure of the partial pressure of CO2
PCO2
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As Pco2 levels rise, breathing is_______________. If Pco2 levels rise too high, breathing cannot keep up with the demand to blow off or ventilate
stimulated
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Most of the CO2 content in the blood is....
HCO3-
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As the HCO3- is directly proportional. HCO3-
− level increases, the __________ also increases
− level increases, the __________ also increases
pH
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indirect measure of the O2 content of the arterial blood
- a measure of the tension (pressure) of O2 dissolved in the plasma.
- a measure of the tension (pressure) of O2 dissolved in the plasma.
PO2
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when is PO2 level decreased (x3)
1. patients who are unable to oxygenate the arterial blood because of O2 diffusion difficulties (eg, pneu-monia, shock lung, congestive failure)
2. patients in whom venous blood mixes prematurely with arterial blood (eg, congenital heart disease)
3. patients who have underventilated and overperfused pulmonary alveoli (pickwickian syndrome; ie, obese patients who cannot breathe properly when in the supine position or in patients with signifi-cant atelectasis).
2. patients in whom venous blood mixes prematurely with arterial blood (eg, congenital heart disease)
3. patients who have underventilated and overperfused pulmonary alveoli (pickwickian syndrome; ie, obese patients who cannot breathe properly when in the supine position or in patients with signifi-cant atelectasis).
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an indication of the percentage of hemoglobin saturated with O2. When 92% to 100% of the hemoglobin carries O2, the tissues are adequately provided with O2, assuming normal O2 dissoci-ation
O2 saturation
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as the ______ level decreases, the percentage of hemoglobin saturation also decreases
PO2
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O2 saturation is calculated by a blood gass machine using what formula?
% O2 saturation= volume of O2 content Hgb/ volume of O2 Hgb capacity
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a calculated number that represents the amount of O2 in the blood.
O2 content
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what is the O2 content equation
O content = O saturation x Hgb x 1.34+PO2 x 0.003
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contraindications to taking arterial blood gasses
• There is no palpable pulse. • Cellulitis or open infection is present in the area considered for access. • The Allen test is negative, indicating that there is no ulnar artery. If the radial artery is used for ac-cess, thrombosis may occur and jeopardize the viability of the hand.
• There is an AV fistula proximal to the site of proposed access. • The patient has a severe coagulopathy
• There is an AV fistula proximal to the site of proposed access. • The patient has a severe coagulopathy
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O2 saturation can be falsely (increased/fdecreased) by inhaling CO which increases the carboxyhemoglibin level
increased
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In patients with chronic obstructive pulmonary disease (COPD), the stimulus to breathe is not trig-gered by ________ levels (as normal) but by __________ levels. If a large amount of O2 is provided to these patients, they will no longer be driven to breathe and will hypoventilate
CO2; O2
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normal cholesterol adult/elderly
<200mg/dL
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testing is used to determine the risk for coronary heart disease (CHD). It is also used for evaluation of hyperlipidemias
cholesterol
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which cholesterol is assocated with risk of CHD
LDL
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Because the liver is required to metabolize ingested cholesterol products, subnormal cholesterol lev-els are indicative of....
severe liver disease
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malnutrition is associated with (high/low) cholesterol level
low
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pregnsncy is assocoiated with (elevayed/depressed) cholesterol levels
elevated
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the recumbant position is asasociated wuth (increase/decreased) cholesterol levels
decreased
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used to support the diagnosis of myocardial muscle injury (infarction). It can also indicate muscle diseases or injury.
creatine kinase (CPK)
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where is Creatine kinase located
inner mitochondrial membrane, myofibrils, muscle cytoplasm
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a syndrome characterized by muscle necrosis and the release of CK into
circulation (mainly CK-MM).
circulation (mainly CK-MM).
rhabdomyolysis
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CK in skeletal muscle
CK-MM
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CK in cardiac tissue
CK MB
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CK in brain tissue
CK BB
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these injections can cause elevated CK levels
intramuscular
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tese used to identify intravascular clotting.
D dimer
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D dimer test assesses levels of this (x2)
thrombin and plasmin activity
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test is used to diagnose factor V-Leiden thrombophilia.
factor V leiden test
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an important factor in reaction 4 (common pathway) of normal hemostasis
factor V
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refers to an inherited abnormal form of factor V in which there is a specific glutamine-to-arginine substitution at nucleotide 1691 in the gene for factor V.
Factor V-Leiden
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why is factor V ;leiden a problem
prorein C cannot innactovate it because of the mutation therefore FVL is therefore inactivated at a rate approximately ten times slower than normal factor V and persists longer in the circulation. This results in increased thrombin generation and a mild hypercoagulable state reflected by elevated levels of prothrombin fragment F1 + 2 and other activated coagulation markers.
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activated protein C resistance test
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normal HDL male
>45 mg/dL
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normal female HDL
>55 mg/dL
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normal LDL adult
<130 mg/dL
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considered to be an accurate predictor of heart disease. As part of the lipid profile, these tests are performed to identify persons at risk for developing heart disease, to decide when to initiate statin therapy, and to monitor therapy if abnormalities are found
lipoprotein test
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proteins in the blood whose main purpose is to transport cholesterol, triglycerides, and other insoluble fats. They are used as markers indicating the levels of lipids within the bloodstream
lipoproteins
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large lipoprotein carry triacylglycerol (fat) from the intestines to the liver, skeletal muscle, and to adipose tissue
chylomicrons
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—carry (newly synthesized) triacylglycerol from the liver to adipose tissue
very low density lipoprotein (VLDL)
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are intermediate between VLDL and LDL. They are not usually detectable in the blood
intermediate density lipoprotreins (IDL)
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carry cholesterol from the liver to cells of the body. Sometimes referred to as the “bad cholesterol” lipoprotein.
low density lipoprpteins (LDL)
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—collects cholesterol from the body’s tissues (and vascular endo-thelium) and brings it back to the liver. Removing lipids from the endothelium (reverse cholesterol transport) provides a protective effect against heart disease. Therefore HDL is referred to as the
“good cholesterol” lipoprotein.
“good cholesterol” lipoprotein.
high density lipoprotein *HDL)
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HDL
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____- levels of HDL are believed tp increase a persons risk for CAD
low
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LDL cholesterol fprmula
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when is this formula innacurate for determining LDL
if triglyceraides exceed 400 mg/dL
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which LDLs are small and therefpre can get between endothelialn cells and cause atheromatous disease
LDL IIIa and b
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seen in patients with mostly large LDL particles and does not carry increased risks for CAD.
LDL pattern A
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seen in patients with mostly small LDL particles and is associated with an increased risk for CAD
LDL pattern B
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they have small and large LDL particles and experience an intermediate risk for CAD. LDL levels can be lowered with diet, exercise, and statins
intermediate LDL pattern
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m issued an
evidence-based set of guidelines on cholesterol management.
evidence-based set of guidelines on cholesterol management.
adult tratment panel III of the national cholesterol education program
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smoking an alcohol )increase/decrread) HDL levels
HDL values like cholesterol (inctrease/decrease) significant following a myocardial infarctopm
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________ is elevated in patients with hy[pothyrpid and diminished in thpose with hyperthyroid (lipid pannel)
HDL
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test is used to assess the intrinsic system and the common pathway of clot formation. It is also used to monitor heparin therapy.
PTT test
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thrombin
convert fibrinogen to fibrin
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what dpes the PTT evaluate
factors I (fibrinogen), II (prothrombin), V, VIII, IX, X, XI, and XII.
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When a thromboembolic epi-sode (eg, pulmonary embolism, arterial embolism, thrombophlebitis) occurs, immediate and complete anticoagulation is most rapidly and safely achieved by _____________ administration.
heparin
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used to evaluate the adequacy of the extrinsic system and common pathway in the clotting mechanism
prothrombin time
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what does PT measure?
clotting ability of factors I (fibrinogen), II (prothrombin), V, VII, and X (ie, the
extrinsic system and common pathway).
extrinsic system and common pathway).
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Alcohol intake can prolong ________ times
PT
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A diet high in fat or leafy vegetables may __________ PT times. Absorption of vitamin K is enhanced.
shorten
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adult female tiglyceride normal
35-135 mg/dL
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adultr male normal triglycerides
40-160 mg/dL
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identify the risk of developing coronary heart disease (CHD). This test is part of a lipid profile that includes the measurement of cholesterol and lipoproteins. This test is also performed on patients with suspected fat metabolism disorders
Tryglycerides
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a form of fat in the bloodstream. They are transported by very-low-density lipoproteins (VLDLs) and low-density lipoproteins (LDLs).
tryglycerides
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what makes tryglycerides
made in the liver using glycerol and other fatty acids
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ingestion of alcohol may cause ________ levels of TG by increasing prpduction of VLDL
elevated
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pregancy may (increase.decrease) TG levcels
increase
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This test is performed on patients with chest pain to determine if the pain is caused by cardiac ischemia. It is a specific indicator of cardiac muscle injury. It is also helpful in predicting the possibility of future cardiac events.
cardiac troponin test
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biochemical markers for cardiac disease. This test is used to assist in the evalua-tion of patients with suspected acute coronary ischemic syndrome
cardiac troponins
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Troponins are proteins that exist in skeletal and cardiac muscle that regulate the _________________ in-teraction of myosin with actin for the muscle contractile apparatus.
calcium depenmdent
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two specific cardiac troponins
cardiac troponin T (cTnT) and cardiac troponin I (cTnI)
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used to monitor arterial O2 saturation levels (Sao2) in patients at risk for hypoxemia. This includes patients who are undergoing surgery, cardiac stress testing, mechanical ventilation, heavy se-dation, or lung function testing, or who have multiple trauma. It is also used as an indicator of partial pressure of oxygen (Po2) in patients who may experience hypoventilation, sleep apnea, or dyspnea. This test is commonly used to titrate O2 levels in hospitalized patients.
oximetry
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what does oximetry monitor
SaO2 (ratio of ox hemo to normal hemo)
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Extreme vasoconstriction diminishes blood flow to the peripheral vessels, which decreases the _________________ of oximetry.
accuracy
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extreme alterations in temp may diminish the _______ of oximetry
accuracy
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Oximetry cannot differentiate carboxyhemoglobin saturation from O2 saturation. Therefore, in cases of suspected smoke or carbon monoxide (CO) inhalation, oximetry should not be used to monitor oxygenation. The levels will be falsely _____________
elevated
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oximetry: Fingernail polish and fake nails will interrupt digital readings. Alternatively, the _____________________ can be used
earlobe
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a calculated number that indicates the difference between alveolar O2 and arterial O2
alveolar arterial O2 gradient
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what does it mean if the alveolar in the alveolar arterial gradient in abnormally high
r a problem in diffusing O2 across the alveolar membrane (thickened edematous alveoli) or unoxygenated blood is mixing with the oxygenated blood
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when can thivkened alveolar membranes occur
patients with pulmo-nary edema, pulmonary fibrosis, and acute respiratory distress syndrome (ARDS)
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when does mixing of unoxygenated blood occur (Aa oxygen gradient)
patients with congenital cardiac septal defects, arteriovenous (AV) shunts, or underventilated alveoli that are still being perfused (atelectasis, mucus plug, etc.)
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what is the mutation in individuals with a Factor V Leiden mutation
R506Q
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what is the modified Friedwald equation (CORRECT)
LDL-C=Total cholesterol-(HDL+(Triglycerides/5))