PMLS L8 pt.1

• laboratory examination analysis 


  is a process used to identify the presence or absence or measure the concentration of a substance in blood or other body fluids or material.
• laboratory examination analysis is divided into 3 phases:

  Pre-Examination, Examination, Post-Examination
• Pre-examination or preanalytical phase


  begins for the laboratory when a test is ordered and ends when testing begins.
• 32%-75% of the errors in the laboratory (McPherson et. al, 2011)

  Pre-examination or preanalytical phase
• according to McPherson et. al, 2011


  Pre-examination or preanalytical phase has 32 %- 75 % of the errors in the laboratory
• Pre-examination or preanalytical phase includes:

  patient-related variables, specimen collection and labeling techniques, specimen preservatives and anticoagulants, specimen transport, processing and storage
• examples of processing errors:

  incomplete centrifugation, incorrect log-in, improper storage
• basal state


  refers to the resting metabolic state of the body early in the morning after fasting for approximately 12 hours.
• Basal state refers to the resting metabolic state of the body early in the morning after fasting for approximately 12 hours.
• SIDEBAR: BASAL STATE & ESTABLISHING REFERENCE RANGE
• Basal-state specimen is ideal for establishing reference ranges on inpatients.
• Out-patient are not basal state specimen, and they might have a slightly elevated reference range
• Reference range or reference interval


  are results used for comparison within a range of values with high and low limits.
• Reference range or reference interval


  Obtained from normal, healthy individuals. some tests have age-specific or specific to certain illnesses or disorders
• PHYSIOLOGIC FACTORS AFFECTING THE PRE-EXAMINATION PHASE

  age, altitude, dehydration, diet, diurnal/circadian variation, drug therapy, exercise, environmental factors, fever, sex, intramuscular injection, jaundice/icterus, pregnancy, smoking, stress
• age 


  Newborn, childhood to puberty, adult, elderly adult
• infants

  Increase in RBC & WBC, HbF, bilirubin, ALP, creatinine Low glycogen reserve
• adults

  Increased levels of albumin, ALP, cholesterol, phosphorus, and uric acid and decrease in hormones and kidney clearance
• Increase in 2 mg/dL per year for cholesterol and triglyceride for both middle aged men and women
• Uric acid peak levels at mid 20’s for men
• age 50 : men will decrease secretion of testosterone while females will increase secretion of FSH
• ALTITUDE

  ✓ Increase in RBC, Hematocrit, Hemoglobin, C-reactive Protein and Uric Acid

  ✓ Decrease urinary creatinine and plasma renin
• ALTITUDE

  ✓ Increase in RBC, Hematocrit, Hemoglobin, C-reactive Protein and Uric Acid

  ✓ Decrease urinary creatinine and plasma renin
• ALTITUDE

  ✓ Increase in RBC, Hematocrit, Hemoglobin, C-reactive Protein and Uric Acid

  ✓ Decrease urinary creatinine and plasma renin
• dehydration 


  decrease in total body fluid due to diarrhea or vomiting
• Hemoconcentration


  increase in RBC, enzymes, iron, Ca2+ , sodium, potassium & coagulation factors
• DIET


  effects on analytes and temporary and may vary depending on food
• Typical overnight fasting time is 8 – 12 hours depending on the test
• Recent food ingestion – increased levels of glucose, triglycerides, cholesterol, gastrin and free calcium; decreased levels electrolytes, ALP and amylase
• ✓Recent food ingestion – increased levels of glucose, triglycerides, cholesterol, gastrin and free calcium; decreased levels electrolytes, ALP and amylase
• Recent food ingestion – increased levels of glucose, triglycerides, cholesterol, gastrin and free calcium; decreased levels electrolytes, ALP and amylase
• High protein, low carbohydrate diet:

  increased in ammonia, uric acid, ketones in the urine
• High protein, low carbohydrate diet:

  increased in ammonia, uric acid & ketones in the urine
• Fat-rich diet – increased potassium, ALP, TAG and 5-hydroxyindole acetic acid (5-HIAA)
• Serotonin-rich food (BAToPin) 


  – increased in urinary 5-HIAA
• Caffeine increases glucose concentration and catecholamines
• Increased water intake: hemoglobin and electrolytes can decrease
• Recent ingestion of alcohol: increase in TAG and liver enzymes
• Long term starvation: decrease in cholesterol, TAG and urea, increase in creatinine, ketone and uric acid levels
• diurnal: daily ; circadian: 24-hour cycle