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• Pre-analytical testing phase


  Includes procedures such as laboratory handling and identification, which take place before any laboratory testing
• Pre-analytical testing phase


  • Strict and proper control measures should be observed to avoid further issues
  • It starts when the doctor's order is given and ends when the laboratory testing has officially commenced
• Physiological variables that influence laboratory results

  • Age
  • Altitude
  • Dehydration
  • Diet
  • Diurnal variation
  • Drug therapy
  • Exercise/ IM injection
  • Fever
  • Gender
  • Jaundice
  • Intramuscular injection
  • Position
  • Pregnancy
  • Smoking
  • Stress
  • Temperature & Humidity
• Blood composition affected by physiological variables

  • RBC, WBC, Creatine Clearance
  • RBC
  • Hemoconcentration, RBC, Enzymes, Iron, Ca, Na
  • Glucose, Lipids, Electrolytes
  • TSH, Cortisol, Iron
  • Enzymes, Hormones
  • pH, Pco2, CK, LDH, Glucose
  • Hormones, cortisol
  • RBC, Hgb, Hct
  • Yellow color interfaces due to increased bilirubin
  • CK, LDH
  • Protein, K
  • RBC
  • Cholesterol, Cortisol, Glucose, GH, TAG, WBC
  • WBC, Iron, ACTH, Catecholamine, Cortisol
  • Hemoconcentration
• Problem areas to avoid and troubleshooting in the site selection

  • Burns, scars and tattoos
  • Damaged veins- could be sclerosed, hardened, thrombosed or clotted
  • Edema/ Oedema- accumulation of fluids in the tissues
  • Hematoma- leakage of blood from the vessels during venipuncture
  • Mastectomy- tourniquet could not be applied in this arm because it can cause injury
  • Obesity- deep and difficult to locate; use a longer tourniquet, palpate the cephalic or cubital vein
• Vascular access sites and devices

  • Arterial Line
  • Arteriovenous shunt or Fistula
  • Blood-sampling Device
  • Heparin or Saline Lock/ "hep-lock"- for medicine administration or blood sampling
  • IV Sites- phlebos should collect below IV lines
  • Central Vascular Access Devices (CVADs)/ Indwelling lines- it could be a central venous catheter lines, implanted port, peripherally inserted central catheter
• Handling patient complications associated with blood collection

  • Allergies to Equipment and Supplies
  • Excessive Bleeding
  • Fainting
  • Nausea and Vomiting
  • Pain
  • Petechiae
  • Seizures or convulsions
• Allergies to Equipment and Supplies

  • Adhesive allergy- apply gauze for 15 mins
  • Antiseptic allergy- use a different antiseptic technique
  • Lates allergy- use nonlatex gloves, tourniquet, bandages
• Excessive Bleeding- pressure should be applied until bleeding stops
• Fainting- lie down during procedure
• Nausea and Vomiting- discontinue procedure until patient feels better
• Pain- if pt complains extreme numbness or pain, remove needle and apply ice to site because this may indicate nerve involvement
• Petechiae- Small red or purple spot that looks like rashes when tourniquet is applied
• Seizures or convulsions- discontinue asap; check mouth for any obstruction, and patient is protected from any self-injury. Notify first aid personnel
• Avoiding & handling procedural error risks & failure to draw blood

  • Hematoma formation
  • Iatrogenic Anemia
  • Inadvertent Arterial Puncture
  • Infection
  • Nerve Injury
  • Reflux of Anticoagulant
  • Vein Damage
• Hematoma formation


  • Hold pressure over the site immediately after discontinuing the draw
  • Cold compress or ice pack may be offered to help address the swelling
  • Conditions that trigger hematoma: excessive or blind probing, inadvertent arterial puncture, the size of the vein is too small, the needle penetration has gone all through the vein, needle is not completely inserted, tourniquet is still on when the needle was removed, the pressure is not adequate
• Iatrogenic Anemia- blood loss due to blood draw. Phlebo should ensure that only the required volume should be extracted from the patient because a 10% loss of blood could face a threat to the patient
• Inadvertent Arterial Puncture- observed when the filling of the tube happens rapidly and there is a rapid formation of hematoma on the site
• Infection- sterile conditions, veni site should be kept closed for 15 mins
• Nerve Injury- improper site selection, rapid needle insertion, excessive redirection of the needle, and blind probing; phlebo should swim slowly or stop veni and look for alternative sites
• Reflux of Anticoagulant- downward position should be observed and tube should be below the veni site
• Vein Damage- follow proper techniques and avoid blind probing
• Specimen quality issues


  • Hemoconcentration- decrease in fluid content or plasma volume caused by tourniquet that stagnate the flow of blood
  • Hemolysis- rupture of the rbcs, the hgb is then released to the surrounding fluid
  • Partially-filled tube or short draw- phlebo pulls a tube before reaching the required volume; this leads to incorrect blood-to-additive ratio
  • Specimen contamination
  • Wrong or Expired Collection tube
• Troubleshooting failed venipuncture

  • Needle not inserted far enough
  • Bevel partially out of skin
  • Bevel partially into vein
  • Bevel partially through vein
  • Bevel completely through vein
  • Bevel against vein wall
  • Needle beside vein
  • Undetermined position
• Collapsed veins


  This happens when there is a strong pressure in the vacuum of the tube or plunger; the tourniquet is too close to the site or is too tight; or the tourniquet has been removed during the draw
• Tube vacuum- phlebotomist should make sure that the bevel is not partially out of skin and the tube itself is not damaged