PHLEB LEC ( pre-analytical )

• Begins when a test is ordered and ends when testing begins

  pre-analytical
• Numerous factors associated with this phase of testing process, if not properly addressed, can lead to errors that can compromise specimen quality, jeopardize the health and safety of the patient, and ultimately increase the cost of medical care

  pre-analytical
• consists of rangevalues with high and low limits

  Reference Range / Intervals 
• Test confirm health or screen, diagnose, &monitor disease; For healthy fasting individuals

  Reference Range / Intervals
• resting state of the body early in themorning after fasting 12 hours

  Basal State
• specimen: ideal for establishing reference ranges on inpatients because the effects of diet, exercise, and other controllable factors on test results are minimized or eliminated; influenced by age, gender, and conditions of the body

  Basal State
• values for some blood components vary considerably depending upon the age of the patient

  Age
• RBC and WBC values are normally higher in newborns than adults; Creatinine levels are higher in elderly patients

  Age
• Decreased oxygen levels at higher altitudes cause the body to produce more RBCs to meet the body’s oxygen requirements


  Altitude
• causes hemoconcentration (blood that cannot leave the bloodstream become concentrated)

  Dehydration
• difficult to obtain blood specimens from dehydrated patients

  dehydration
• blood analyte composition can be altered by the ingestion of food and drink

  diet
• requiring a patient to fast or follow a special diet eliminates most dietary influences on the test

  diet
• factors include posture, activity, eating, daylight and darkness, and being awake or asleep.

  Diurnal / Circadian variations
• some drugs alter physiological functions, causing changes in the concentrations of certain blood analytes

  Drug Therapy
• can also interfere with actual test procedure, causing false increases or decreases or enhance the reaction

  drug therapy
• depending on the patient’s physical condition and the duration and intensity of the activity

  exercise
• moderate to strenuous appears to have the greatest effect; vigorous exercise shortly before blood collection can temporarily increase cholesterol levels by 6% or more

  exercise
• affects the levels of a number of hormones

  fever
• fever induced hypoglycemia increases insulin & glucagon levels; increases cortisol and may disrupt normaldiurnal variation

  fever
• most differences are apparent only after sexual maturity

  gender
• RBC, HgB, and Hct are higher in males


  gender
• can increases levels ofcreatinine kinase and skeletal muscle fraction of LDH

  Intramuscular injection
• also called icterus is an increased inbilirubin


  Jaundice
• abnormal color can interfere with chemistrytests based on color reactions, includingreagent strip analysis


  jaundice
• body position before and during bloodcollection can influence specimen composition

  Position
• increases body fluid, diluting effect on theRBCs leading to lower RBC count

  pregnancy
• patients who smoke prior to specimencollection may have increased cholesterol, cortisol, glucose, growth hormone, triglyceride levels and WBC count

  smoking
• emotional stress can cause transientelevations in WBC

  stress
• crying infants have increased in WBC count

  stress
• also decrease serum iron levels andincrease adrenocorticotropic hormone (ACTH),catecholamine, and cortisol levels

  Stress
• influence composition ofbody fluids

  Temperature and Humidity
• acute heat exposure cause interstitial fluids tomove into the blood vessels, increasing plasmavolume and influencing its composition

  Temperature and Humidity
• Veins are difficult to palpate and penetrate

  Burns, scars and tattoos
• Healed Burns have impaired circulation =

  inaccurate results
• New burns are


  painful, infection
• Tattoos have ___, ___, ___ = inaccurate results


  impaired circulation, infection, dyes
• Insert needle where there is

  no dye
• Sclerosed or ?


  hardened veins
• Thrombosed or ?


  clotted veins