PMLS2_LEC8 Flashcards
● For diagnosis and monitoring
● Collected early morning or during collection sweeps or schedule
● Collected from the outpatient department (OPD) patients
ROUTINE SAMPLES
● Response time varies from each laboratory; what sample
ASAP SAMPLES
● For managing of critical cases
● Collected, analyzed, and results are reported
immediately
STAT SAMPLES
Factors that can influence the composition of blood:
To try to eliminate these factors, we try to collect
blood when the body is in a _____.
○ Age
○ Altitude
○ Body position
○ Dehydration
○ Diet
○ Diurnal variation
○ Drugs
○ Environment
○ Exercise
○ Gender
○ Pregnancy
○ Smoking
○ Stress;
basal state
Body’s state after 8 to 12 hours of fasting and
abstention from strenuous exercise.
BASAL STATE
Fasting and timed collection includes:
○ Analytes with Diurnal Variation
○ Therapeutic Drug Monitoring
○ Glucose Tolerance Tests
○ Lactose Tolerance Tests
➔ “Nothing by mouth”
➔ No food and water
NPO
In fasting collection:
Patient Preparation:
● The patient refrains from eating for
a period of time (8-12 hrs)
● Refrains from exercise
Special Procedure:
Phlebotomist will take note of the:
● Time of last meal
● Time of collection
Laboratory Tests:
● Fasting Blood Sugar
● Lipid Panel
● Taken to determine the changes in the level of some substances that are to be monitored over time.
● Samples should be collected at the precise time;
laboratory tests of these are:
TIMED COLLECTION;
● Myoglobin
● Troponin I
● CPK-MB
● Prothrombin Time
● APTT
Reasons for Timed Samples:
● Measurement of the body’s ability to metabolize a
particular substance
● Monitoring changes in a patient’s condition (such as a
steady decrease in hemoglobin)
● Determining blood levels of medications
● Measuring substances that exhibit diurnal variation
(normal changes in blood levels at different times of
the day)
● Measurement of cardiac markers following acute
myocardial infarction
● Monitoring anticoagulant therapy
occurs when substances that exhibit diurnal variation change their levels at different times
of the day.
● Recommended collection time is when they are at their peak level.
DIURNAL VARIATION
LABORATORY TESTS PEAK TIME
Plasma Cortisol 8:00 - 10:00 AM
Serum Iron 8:00 - 10:00 AM
Hormones Morning Collection
Leukocytes Morning Collection
● To manage patients being treated with certain drugs in order to help establish a drug dosage.
● While adjusting the dosage when in combination with other drugs taken.
● Identifying noncompliant patients
● Maintaining the dosage at a therapeutic (beneficial) level.
● To avoid drug toxicity
THERAPEUTIC DRUG MONITORING
Time of collection (therapeutic drug monitoring) depends on the time the medication was given.
○ Intravenous (IV) - ____ (after the
medication was given);
○ Intramuscular (IM) - _____;
○ Oral dosage - _____
30 minutes; 1 hour; 1 to 2 hours
➔ Shortly after the medication was given.;
➔ Time right before the next dosage is given.
PEAK LEVEL; TROUGH LEVEL
● Used for the diagnosis of diabetes mellitus and
differentiating it from gestational diabetes
GLUCOSE TOLERANCE TESTS
● For diabetes mellitus, use to monitor insulin therapy
● It compares the fasting glucose level with the level 2 hours after consuming glucose (Full meal is consumed after the 1st blood testing)
● Normally glucose will go back to fasting level 2 hours after the meal
2 HOUR POSTPRANDIAL (2HPP)
● Done for diabetes mellitus and gestational diabetes
● The patient drinks a standard glucose load (75 / 100 gm) and returns for testing on an hourly basis up to 6 hours in length.
● For small adults & children: 1 g/kg body weight
CLASSIC GLUCOSE TOLERANCE TEST
CONTRAINDICATIONS FOR CLASSIC GLUCOSE
TOLERANCE TEST:
● Smoking during the test period
● Patient is under extreme stress
● Eating a snack or candy after the meal and before testing
● Unable to consume entire meal / solution
● Exercise during the testing period
MEDICATIONS THAT PATIENT MUST STOP 3-5 DAYS BEFORE THE TEST:
● Alcohol
● Anticonvulsants
● Aspirin
● Birth control pills
● Blood pressure medications
● Corticosteroids
● Diuretics
● Estrogen-replacement pills
● The recommended method for the diagnosis of
diabetes mellitus.
● Same procedure as 2HPP but uses a glucose
solution instead of a full meal as glucose load.
2-HOUR ORAL GLUCOSE TOLERANCE TEST
● 1-hour glucose screening test or gestational glucose screening test.
● Special Procedure:
○ Px drinks 50 gm of glucose solution
○ Test for Glucose 1 hour after
●____ = abnormal results (px is recommended
for follow-up testing)
ORAL GLUCOSE CHALLENGE TEST;
>140 mg/dL
➔ Utilizes the same procedure as the diagnostic
Oral Glucose Tolerance Test (OGTT) used to
diagnose diabetes mellitus
ONE-STEP METHOD FOR
GESTATIONAL DIABETES
➔ Done for 2 days
◆1st day: Oral Glucose Challenge Test
(OGCT) is done
◆2nd day: Oral Glucose Tolerance Test
(OGTT) is done
TWO-STEP METHOD FOR
GESTATIONAL DIABETES
● Used to determine if a patient lacks the mucosal lactase that is necessary to convert lactose, or milk sugar, into glucose and galactose.
● Patients with lactose intolerance experience
gastrointestinal discomfort and diarrhea.
● Same procedure as a 2-hr OGTT, but the patient drinks a lactose solution instead.
LACTOSE TOLERANCE TEST
