PMLS2 Lec6

• Pre-Analytical Testing Phase


  • Includes procedures such as laboratory handling and identification, which take place prior to any laboratory testing. In this phase, proper control measures are placed to avoid subsequent issues. It starts when the doctor's order is given and ends when the laboratory testing has officially commenced.

  • During this phase, the phlebotomist must not only be able to draw blood from the patient, but must also be able to identify factors that affect the process and address them as needed.
• Laboratory Test


  • Is used by physicians to diagnose and monitor the presence of a disease.

  • The physicians compare the results to a reference range or reference interval. This range shows the high and low limits of result values as compared to healthy individuals. Several factors are considered as part of the reference interval study or the interpretation of the data obtained.
• Basal State


  • Is ideal in establishing reference range since it represents the condition of the metabolism of the body early in the morning or after approximately 12 hours of fasting. This can be influenced by age, gender, and conditions of the body.
• Age


  Red blood cells (RBC), white blood cells (WBC), creatinine clearance
• Altitude or Pregnancy


  Red blood cells (RBC)
• Dehydration


  Hemoconcentration, red blood cells (RBC), enzymes, iron (Fe), calcium (Ca), sodium (Na)
• Diet


  Glucose, lipids, electrolytes
• Diurnal Variation


  Thyroid-stimulating hormone (TSH), cortisol, iron (Fe)
• Drug Therapy


  Enzymes, hormones
• Exercise/IM Injection


  Potential of hydrogen (pH), carbon dioxide partial pressure (PCO,), Fever creatine kinase (CK), lactic acid dehydrogenase (LDH), glucose
• Fever


  Hormones, cortisol
• Gender


  Red blood cells (RBC), hemoglobin (HgB), hematocrit (Hct)
• Jaundice


  Yellow color interfaces due to increased biliburin
• Intramuscular Injection


  Creatine kinase (CK) and the skeletal muscle fraction of LDH
• Position

  Protein, potassium (K)
• Smoking


  Cholesterol, cortisol, glucose, growth hormones (GH), triglyceride, white blood cells (WBC)
• Stress


  White blood cells (WBC), iron (Fe), adrenocorticotropic hormone (ACTH), catecholamine, cortisol
• Temperature and Humidity


  Hemoconcentration
• Burns, Scars, and Tattoos


  • It is not advisable to choose a site that has burns, scars, or tattoos because veins in the area may be difficult to examine and blood circulation may be impaired.

  • Burns may be too painful to touch and tattoos may also be susceptible to infection due to the dyes used that may interfere with the process.
• Damaged Veins


  • Aside from being difficult to perform, puncturing damaged veins may also produce inaccurate results. Veins could be sclerosed or hardened or thrombosed or clotted.
• Edema


  • A so known as Oedema, is an abnormal swelling caused by the accumulation of fluid in the tissues. The tissues become fragile, making the task of locating the veins harder.

  • This condition may be due to reactions from medications, pregnancy, infections, and other medical problems.
• Hematoma


  • Is a solid swelling or mass of blood in the tissues caused by the leakage of blood from the vessels during venipuncture.

  • Selecting a venipuncture site with hematoma will be painful for the patient because it will obstruct the blood flow. It could also lead to the contamination of blood sample.
• Mastectomy


  • This procedure, often done to breast cancer patients, refers to the removal of the breast through surgery.

  • Blood drawing from patients who had undergone this procedure becomes a challenge since the lymph flow is obstructed, and there may be swelling and infection after the surgery. In addition, tourniquet cannot be applied because it can cause injury. It could also change the blood composition.
• Obesity


  • This is the condition in which the individual is grossly overweight.

  • Patients who are obese have veins that are deep and difficult to locate. A solution is using a longer tourniquet or locating the cephalic or cubital vein.
• Arterial Line


  • To obtain samples for arterial blood gas and laboratory studies, critically ill patients require arterial lines where a thin catheter is inserted into an artery.

  • This is also used to monitor blood pressure continuously.

  • Neither tourniquet nor venipuncture is allowed in the arm with an arterial line.
• Arteriovenous Shunt or Fistula


  • Is a passageway created through surgery, and is usually in the arms with the intention of connecting the artery and a vein directly. This may be created for hemodialysis treatment or pathological process such as erosion of arterial aneurysm.
• Blood-sampling Device


  • Is used to avoid the use of needle-sticks, prevent infections, and reduce wastage from line draws.

  • The device collects blood from the arterial or central venous catheter where it is connected.
• Heparin of Saline Lock


  • Is commonly called a "hep-lock" is an intravenous (IV) catheter attached to a stopcock or cap with diaphragm.

  • Its basic function is to provide access for administering medicine or drawing blood from the patient. It is threaded in the peripheral vein, which is in the lower arm above the wrist for up to 48 hours. It is usually flushed with heparin or saline (to prevent clogging) and capped for future use.
• Intravenous (IV) sites


  • An IV line is a thin plastic tube or catheter inserted into a vein in the forearm to inject a volume of fluids into the bloodstream.

  • The phlebotomist should avoid collecting blood from the arm with IV because the blood collected could be contaminated with IV fluid. If blood collection is necessary, the collection site should be below the IV. Take note that collection of blood from previously known IV sites should be avoided for 24 to 48 hours.
• Central Vascular Access Devices (CVADs)


  • Also known as indwelling lines, are any of the tubings inserted to the main vein or artery used for blood collection, monitoring the patient's pressures, and administering medications and fluids.
• Three (3) types of CVADs

  • central venous catheter lines
  • implanted port
  • peripherally inserted central catheter
• Central Venous Catheter


  also known as a central line inserted into the large vein (subclavian) and advanced into the superior vena cava.
• Implanted Port


  surgically implanted disk-shaped chamber attached to the indwelling line. This is usually placed on the upper chest just below the collarbone.
• Peripherally inserted central catheter (PICC)


  a flexible tube inserted into the veins of extremities and the central veins.
• • When the patient has adhesive allergy, a gauze should be placed over the site and should be removed after 15 minutes.

  • The alternative is to ask the patient to apply pressure for five minutes. When the patient has antiseptic allergy, simply use a different antiseptic.

  • When the patient has latex allergy, look for a sign to indicate the allergy and use a non-latex alternative for gloves, tourniquet, and bandages.
• Excessive Bleeding


  • When a patient is on aspirin or anticoagulant, the bleeding may take a longer time.

  • The pressure should be applied to the site until the bleeding stops. The attention of the authorized personnel should be called when the bleeding continues after five minutes.
• Fainting


  • Is a temporary loss of consciousness which is caused by the insufficient flow of blood to the brain.

  • Patients prone to fainting during venipuncture are asked to lie down during the procedure.
• Nausea and Vomiting


  • When the patient feels nauseous and has the tendency to vomit, the phlebotomist has to discontinue the procedure until the patient feels better or until the feeling subsides.

  • An emesis basin or wastebasket should be provided, and a cold damp washcloth should be applied to the forehead.
• Pain


  • The patient should be warned before the needle insertion, and the phlebotomist should avoid redirection of the needle.

  • If the patient complains of extreme pain or numbness, remove the needle and apply ice to the site because this could indicate nerve involvement. The phlebotomist needs to document the incident if the condition persists.
• Petechiae


  • This condition involves the appearance of small red or purple spots that look like rashes, which appear on the arm when tourniquet is applied.