Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
60 Cards in this Set
- Front
- Back
|
Steps for sucessful lab assessment
|
Symptoms, Signs, and Chest Xray
Presumptive Diagnosis Confirm with lab results |
|
|
Lab Assessment Facts
|
Diagnosis is seldom made from lab results alone
-lab results and clinical findings usually lead to the most accurate results |
|
|
False Negative
|
A normal test result for a pt with the disease that the test is designed to detect
|
|
|
False Positive
|
An abnormal test result for a normal pt without the disease that the test is designed to detect
|
|
|
Each lab determines its own normal values based on..
|
Testing procedures
choice of equipment |
|
|
Normal Lab values
|
Expresses as ranges to include 95% of the normal population
Two standard deviations higher and lower than the mean normal ranges are typical of most labs but not absolute national values |
|
|
CBC
|
Comp. Blood Count
Red Blood Cells (RBC) White Blood Cells (WBC) Platelet count |
|
|
RBC
|
Red Blood Cells
Hematocrit (Hct) Hemoglobin (Hb) |
|
|
WBC
|
Neutrophils
Bands Eosinophils Basophils Monocytes Lymphocytes |
|
|
RBC Count
|
Normal:
-Men=4.6-6.2 x 10^6/mm^3 -Women=4.2-5.4 x 10^6/mm^3 Produced in Bone marrow Life span: 120 days |
|
|
Hct
|
Hematocrit - Packed cell vol.
The ratio of red cell volume to that of whole blood Determined by centrifuging whole blood Packed cells measured vs total blood volume in tube Expressed as a % Normal -Men 40-54% -Women 38-47% |
|
|
Hb
|
Each gram % of Hb is capable of carrying 1.34 mL of oxygen
Men 13.5-16.5 g/dl Women 12-15 g/dl If Hb is less than 8 g/dl -value is critacally low -will require blood transfusion with 2 unit packed RBC's |
|
|
Anemia
|
Lower than normal RBC count
Caused by -Blood Loss -Decreased Production -Increased destruction |
|
|
Polychthemia
|
Term to decribe an increase in the RBC count, Hb, and Hct
2 types -Primary poly -Secondary poly |
|
|
Primary Polycythemia
|
Cause by uncontrolled proliferation of hematopoietic cells in bone marrow
uncommon |
|
|
Secondary Polycythemia
|
Caused by Chronic Hypoxemia
-Stimulates renal production of erythropoietin -More RBC produced and released from the bone marrow -Attempt to compensate for lower than normal PaO2 (increases carrying capacity of blood) More common Diseases/Conditions which cause Chronic Hypoemia -Severe COPD -Pulmonary Fibrosis -People who live at high alt |
|
|
Hazards of Polycythemia
|
Increased blood viscosity
-increases work of heart -decreases circulation and oxygen delivery to tissues Increases risk of clot formation |
|
|
WBC Function
|
Part of immune system to fight infection
|
|
|
Normal Ranges for WBC
|
Men and women - 3500-11000mm^3
-Too few will decrease ability to fight infection -Too many is a sign of an active infection |
|
|
WBC made in Bone Marrow
|
Neutrophils
-bandcells Eosinophils Basophils Monocytes |
|
|
WBC made in Lymphnodes and Thymus Gland
|
Lymphocytes
|
|
|
Differential White Count
|
Defines the percentage of the total WBC count made up by each type of WBC
|
|
|
Neutrophils
|
PMN's
Normal = 40-75% Destroys bacteria When elevated, suggests bacterial infection |
|
|
Bands Cells
|
A less mature neutrophils
Nucleus not yet segmented Normals bands count = 0-6% |
|
|
Eosinophils
|
Normal = 0-6%
Involved in -allergic reactions along with basophils -parasitic infections |
|
|
Basophils
|
Normal = 0-1%
Involved in allergic reactions along with eosinophils |
|
|
Monocytes
|
AKA Macrophages
Phagocytosis of organisms and foreign material Normal = 2-10% |
|
|
Lymphocytes
|
Normal = 20-45%
Defends against viral infections, TB and fungal infections 2 types -T -cells -B-cells |
|
|
Leukocytosis
|
A general increase in the total number of WBC's
|
|
|
Leukopenia
|
A general decrease in the total number of WBC
Common Causes -Leukemia -Chemotherapy -Radiation Therapy |
|
|
Cytosis
|
Higher then normal #
|
|
|
Penia
|
Lower than normal #
|
|
|
Neutrophilic Leukocytosis
|
An increase in the # of Neutrophils
Common response to -Bact. infection -Inflammation (burns, snake bites, parasitic infection) -Systemic Steroids (prednisone) -Epinephrine |
|
|
Left Shift
|
Condition where bone marrow is realeasing large numbers of immature neutrophils (bands) faster than it can produce them
|
|
|
Neutrophilic Leukopenia
|
A decrease in the total number of Neutrophilic
Common causes -Chemotherapy -Bone Marrow Disease -Cancers affecting Bone Marrow -Overwhelming Bacterial Infection |
|
|
Eosinophilic Leukocytosis
|
An increase in the total number eosinophils
Common causes -Allergic states -Allergic Asthma |
|
|
Lymphocytosis
|
An increase in the total # of Lymphocytes
Common causes -viral infection |
|
|
Lymphocytopenia
|
A decrease in the total # of lymphocytes
Common causes -HIV |
|
|
Monocytosis
|
An increase in the total # of monocytes
Common causes -Chronic infections (TB, fungal) |
|
|
Platelets
|
Smallest of formed elements in the blood
Normal Range = 150-440 /nl |
|
|
Platelet function
|
Blood coagulation thru formation of blood clots
|
|
|
Thrombocytopenia
|
An abnormal decrease in the number of platelets
When the platelet count becomes extremely low Less than 50/nl, the pt is at riak for -spontaneous internal hemorrage Prolonger bleeding times (surgery, arterial puncture) |
|
|
Coagulation Studies
|
Assessment of the pt ability to maintain hemostasis (ability to prevent hemorrhage)
|
|
|
APTT
|
Activated Thromboplastin Time
Normal = 24-32 secs Measures length of time for plasma to form a fibrin clot Useful for monitoring heparin therapy |
|
|
PT
|
Prothrombin Time
Normal 12-15 secs Measures length of time for plasma to form a fibrin clot Useful for monitoring coumadin therapy |
|
|
When an RT is going to perform an arterial puncture what should you check to assess the pt clotting ability?
|
Anticoagulant Meds (lovenox, coumadin, Heparin)
APTT PT |
|
|
Electrolytes are essential for normal physiologic function of...
|
Nerve transmission
Muscle Contraction Heart Rhythms |
|
|
Electrolytes are important to watch during..
|
Intravenous fluids
Renal disease (receiving dialysis) Diarrhea (losing electrolytes before they are absorped) |
|
|
Types of Electrolytes
|
Sodium
Potassium Chloride Calcium (heart) Magnesium (heart) Phosphorus (ADP and ATP) |
|
|
Sodium
|
Normal plasma concentrations = 137-147 mEq/L
The major cation of extracellular fluid Kidneys regulate sodium concentrations -Hypernatremia: increased Na levels in the plasma -Hyponatremia: decreased Na levels in the plasma Needed for muscles to contract |
|
|
Potassium
|
Normal Plasma concentrations = 3.5-4.8 mEq/L in extracellular
The major cation within cells -Hyperkalemia: increased K+ levels in the plasma (can lead to significant cardiac dysrhythmias) -Hypokalemia: decreased K+ levels in the plasma (can cause cardiac, skeletal, GI dysfunction) (Complication from some diuretic meds) |
|
|
Chloride
|
Normal plasma concentration = 98-105mEq/L in extracellular fluid
The major anion of extracellular -Hyperchloremia: increased Cl levels in the plasma (prolonged diarrhea, renal disease) -Hypochloremia: Decreased Cl levels in the plasma (prolonged vomitting, chronic resp acidosis) |
|
|
Anion Gap
|
The difference between the measured cations (Na + K) and the measured anions (Cl +HCO3)
Normal gap = 8-16 mEq/L -accounts for unmeasured anions present like: lactate, sulfates, and phosphates Body must maintain eletrical neutrality |
|
|
Use of the anion gap
|
Calculating anion gaps helps define the cause of a metabolic acidosis
|
|
|
High anion gap signifies...
|
Lactic Acid
Ketoacids (diabetic ketoacidosis) Sulfates (renal failure) |
|
|
Sweat (Chloride) Shift
|
Analysis of the amount of Cl- ion in the sweat of a pt suspected with cycstic fibrosis
CF pt have very elevated levels of Cl- in their sweat due to inability of sweat glands to conserve it 60 mEq/L is generally considered diagnostic for CF |
|
|
BUN and Cr
|
Blood Urea Nitrogen and Creatine
Most common blood tests to assess renal function Metabolic Waste products, they are normally filtered and excreted by kidneys If elevated, the kidney arent doing enough to eliminate them |
|
|
Normal BUN
|
7-20 mg/dL
|
|
|
Normal Cr
|
0.7-1.3 mg/dL
|
|
|
Metabolic Acidosis is frequently caused by...
|
Renal failure
Causes added stress on the lungs by increasing MV May lead to increased WOB, fatigue of vent. muscles and resp failure |
