Patient Prep & Specimen Collection - MT 31 Clinical Chemistry I - PDF

Topic 1: Patient Prep & Specimen Collection MT 31 : CLINICAL CHEMISTRY I MT 31...

Topic 1: Patient Prep & Specimen Collection MT 31 : CLINICAL CHEMISTRY I MT 31 SY 2024-2025 MR. ALEX JOEY COLOYAN, RMT 1ST SEMESTER Cyclic Variation OUTLINE I Sources & Control of Pre-Analytical Variation Refer to changes in concentration of analytes that A. Pre-collection Causes of Variation occur in a predictable fashion at certain times of the II Patient Identification day, week or month. III Types of Blood Samples A. Arterial Blood Table 1. Examples of Cyclic Variation B. Venous Blood VARIATION DESCRIPTION a. Steps in Performing Venipuncture Occurs during the course of a b. Complications of Venipuncture Circadian Rhythm c. Causes of Hemolysis single day. d. Causes of Hematoma Substances are not released C. Capillary Blood into the circulation in a Ultradian Variation a. Arterialized Capillary Blood constant fashion but are IV Reasons for Rapid Separation of Blood secreted in episodic bursts. V Interfering Conditions in the Measurement of Analytes Infraradian Cyclic variation over a period VI Storage and Transport of Specimens Variation greater than one day. A. Specimen Consideration B. Ten Common Errors in Specimen Collection Related to seasonal changes Circannual C. Reasons for Specimen Rejection in the diet or climatic Variation VII Evacuated Tubes variation. VIII Blood Tube Collection Guide: Order of Draw Exercise SOURCES & CONTROL OF PRE-ANALYTICAL VARIATION Exercise is a common, controllable cause for variation in laboratory test results. Laboratory tests: Routine chemistry tests that are significantly altered by ○ measure an analyte in a specimen of blood or a brief period of exercise: other body fluid ○ Potassium ○ ordered by physicians to evaluate the status of a ○ Phosphate patient. ○ Creatinine ○ Serum proteins Laboratories are responsible for taking steps to Short-term intensive exercise produces rapid increase minimize sources of error by developing standard in potassium and muscle enzymes procedures that govern patient preparation, Elevated levels of proteins (⬆) in urine sample collection, methods of transport, and In persons training for distance events: preservation of samples Agencies that accredit laboratories, like CAP, Serum gonadotropin Decreased (⬇) require each laboratory to provide a detailed Sex steroid concentrations manual that documents the proper method for Increased (⬆) Prolactin concentration specimen collection. Ideally, such a document should include the Vigorous hand exercise (Fist clenching) increases procedures used to minimize errors at each point potassium. where variation may develop. Diet PRE-COLLECTION CAUSES OF VARIATIONS Diet-related changes in laboratory tests are There are several factors that influence the pronounced for many analytes; most are transient and concentration of analytes in a specimen. These easily controlled. After food ingestion, there is an increase (⬆) in include: concentration of substances absorbed from food. Cyclic Variation Fasting Hormones that are secreted in response to eating, Tourniquet application such as gastrin and insulin, will also show a Exercise Tobacco Smoking postprandial rise. Diet Alcohol Ingestion Alteration in dietary protein intake is associated with Stress Drugs reversible changes in urea excretion Posture The plasma concentration of substances, such as potassium and phosphate, will fall (⬇) after a meal. LAGAT | BSMT III 1  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION Table 2. Summary of Diet-related Changes in Lab Tests Drugs VARIATION ANALYTE Hormones Hepatotoxic drugs can elevate (⬆) liver function Increases (⬆) ○ Gastrin enzymes. After a meal ○ Insulin Diuretics can cause decreased (⬇) plasma sodium Plasma Concentration of: and potassium. Decreases (⬇) ○ Potassium (K) After a meal ○ Phosphate (PO4) PATIENT IDENTIFICATION Stress Proper patient identification is the first step in sample collection – this is the prime factor in Stress, whether mental or physical, can reversibly alter order to obtain accurate results in a clinical results of many laboratory tests laboratory. It is well known that stress induces production of: ○ Adrenocorticotropic hormone (ACTH) Conscious Inpatients/Hospitalized patients ○ Cortisol ○ Catecholamines Verbally ask their full name It also results in hyperventilation which in turn, affects Verify the name using the identification bracelet (First acid-base balance. and last name, hospital/unit number, room/bed number and physician`s name) Posture Sleeping Patients Posture is a readily controllable cause of preanalytical variation. Protein concentration: They are identified in the same manner as conscious In the upright position: in-patients. ○ Increased hydrostatic pressure causes leakage of They must be awakened before blood collection. water and electrolytes from the intravascular fluid compartment, resulting in an increase (⬆) in Unconscious, mentally incompetent patient concentration of proteins. In supine position: They are identified by asking the attending nurse or ○ Water and electrolytes return to the vascular relative. space, resulting in a fall (⬇) in protein ID bracelet concentrations If phlebotomy is performed before a patient is seated Infants and Children for at least 15 minutes after a period of standing, hemoconcentration as great as 5% to 8% occurs. A nurse or relative may identify the patient, or by means of an identification bracelet Fasting Out-patient/Ambulatory patient 8-14 hours: ○ Glucose (8-10 hours) Verbally ask their full name, address, DOB, counter ○ Lipids and lipoproteins (10-12 hours) check with driver’s license. Basal state collection is early morning blood collection, 12 hours after the last ingestion of food NOTES TO REMEMBER Tourniquet application The manner in which a phlebotomist greets a One-minute application is recommended patient can often set the tone for the remainder of Prolonged tourniquet application results to the phlebotomy procedure hemoconcentration and anaerobiosis Phlebotomists must always conduct themselves in a professional manner. Therefore, when greeting a Tobacco smoking patient, be courteous and respectful. When greeting the patient, the phlebotomist must Increased plasma catecholamines and cortisol identify him- or herself and tell the patient why he or she is there. Alcohol Ingestion Do not use the information on the chart that is attached to the bed or on the name plate on or Increased TAG and GGT above the bed. It causes hypoglycemia LAGAT | BSMT III 2  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION TYPES OF BLOOD SAMPLES Veins on the wrist and dorsal aspect of hands Three (3) types of blood samples: ○ Can be chosen provided the ○ Arterial blood antecubital veins are not ○ Venous blood acceptable. ○ Capillary blood Veins on the ankle ○ Should be used only if arm ARTERIAL BLOOD veins have been determined to be unsuitable Is the source of nutrients for all body tissues and is the best sample to use for evaluation of adequate delivery In venipuncture, if a phlebotomist accidentally of necessary substances such as oxygen to the body punctured an artery instead of a vein, he should tissues. immediately apply pressure and report the case to the supervisor. Oxygenated blood Characteristics With bright red color Steps in Performing Venipuncture Collected without a tourniquet Radial artery BEFORE PERFORMING VENIPUNCTURE ○ Modified Allen Test* should be Sites of done before collection from this 1. Positioning and Tourniquet Application Collection artery ○ Position the patient’s arm in such a way that it is Brachial artery comfortable for both of you and the patient, Femoral artery allowing clear access to the antecubital area. Irritated ○ The arm should be supported by a firm surface Unacceptable Edematous such as an armrest on a phlebotomy chair or on Sites Near a wound or in an area of a the bed if the patient is lying down. fistula ○ It is courteous to ask the patient if he or she has Thrombosis an arm preference for the venipuncture, but the Major ultimate decision rests with the Hemorrhage Complications phlebotomist. Possible infection ○ Once the arm is positioned, place the tourniquet firmly about the upper arm. The tourniquet Modified Allen Test needs to be tight enough to increase blood pressure in the veins but not so tight that it cuts Have the patient make a fist and occlude both the off the circulation. ulnar and radial arteries by compressing with two ○ The tourniquet should never remain on the fingers over each artery patient’s arm for more than 1 minute. Have the patient open his or her fist, and observe if the ○ If the blood pressure cuff is used as a patient’s palm has become bleached of blood tourniquet, it is inflated 60 mmHg. Release the pressure on the ulnar artery only, and note ○ If the tourniquet is closer to the site, the vein if blood return is present. The palm should become may collapse as blood is above the intended perfused with blood. Adequate perfusion is a positive venipuncture site. test indicating that arterial blood may be drawn from ○ When a tourniquet is used during preliminary the radial artery. Blood should not be taken if the test vein selection, it should be released and is negative.. reapplied after 2 minutes ○ Studies have shown that reusable tourniquets VENOUS BLOOD have the potential to transmit bacteria, including Methicillin-resistant Staphylococcus aureus Lower concentrations of substances used in (MRSA). metabolism, such as oxygen, glucose, and higher concentrations of waste products 2. Choosing the Site of Collection ○ Try to locate the median cubital vein. ○ Other veins that may be acceptable are: Deoxygenated blood Cephalic vein Characteristics With dark red color Basilic veins Collected without a tourniquet ○ Veins in the back of the hand may also be Antecubital fossa region acceptable, but in these cases, it is wise to use ○ Median cubital: best site pediatric needles and evacuated tubes or Sites of (largest and well-anchored vein) “butterfly.” Collection ○ Cephalic vein: second choice ○ To enhance visualization of the veins, position ○ Basilic: third choice (close the arm at a downward angle, using the force of proximity to the brachial artery) gravity as an aid. LAGAT | BSMT III 3  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION ○ Rubbing the forearm toward the antecubital area Never transfer blood collected in an additive tube and instructing the patient to make a fist may into another additive tube, even if the additives are enhance vein visualization. the same. ○ The prospective venipuncture site should be free of skin abrasions, lesions, and scar tissue. Syringe 3. Assembling the Equipment At one time a syringe was the only option for blood ○ The needle should not be uncovered until ready collection to perform venipuncture. ○ Place any additional tubes to be used in a With the advent of the evacuated tube system, the convenient location, keeping some spares use of a syringe to collect venous blood is no handy. longer routine. A syringe is used to collect blood from veins that Needle may collapse when using an evacuated tube system due to the force of the vacuum. Color coding for needles indicates the gauge Because blood will begin to clot in the syringe, it is The gauge of the needle is inversely related to the imperative that collected blood be added to the size of the needle. anticoagulant tubes first, followed by any other anticoagulant tubes, and then any remaining tubes Table 3. Needle Gauges without anticoagulants. GAUGE LENGTH DESCRIPTION The standard for The phlebotomist should mix the anticoagulant 21-gauge 1-1.5 inches tubes thoroughly after the blood has been added, venipuncture. and it is advisable to carefully remove the syringe Used for children needle to facilitate the addition of blood to the 23-gauge butterfly: tubes. 23-gauge 1-1.5 inches most commonly used for small and When adding the blood, do not “squirt” the blood difficult veins. in the tubes but rather allow the blood to steadily flow down the sides of the tubes. For a winged infusion set. 4. Cleansing the Site of Collection Best for geriatric, ○ Cleanse the venipuncture site with 70% 23/25 gauge ½ to ¾ inch oncology, or isopropyl alcohol by making outward concentric hematologic patients circles. with fragile veins. ○ This must be allowed to dry, either by air drying or by using clean gauze. Using a needle smaller than 23 gauge increases the ○ Once the site is cleansed, it must not be touched; chance of hemolyzing the specimen. if touched, it must be cleansed. If the needle or lancet touched any surface before blood collection, replace it with a new one Table 5. Other Recommended Disinfectants Geriatric, oncology or other hematologic patients DISINFECTANT TESTS can have fragile veins, so it is preferable to use a Should be used for Benzalkonium chloride winged blood collection set or syringe to ethanol testing minimize vessel wall injury and hemolysis. Most common form of skin cleansing before Tubes1 70% alcohol + iodophore drawing blood for culture Tubes with clot activators enhance coagulation to Recommended blood provide more surface for platelet activation. culture site disinfectant Chlorhexidine gluconate for infants 2 months and Table 4. Clotting Time According to Clot Activators older, and patients with CLOT ACTIVATOR CLOTTING TIME TUBE iodine sensitivity Silica Particles 15 to 30 minutes Gold Gel Separators Approx. 30 minutes Gold Thrombin 5 minutes Orange DURING VENIPUNCTURE No additives 60 minutes Red 5. Performing the Venipuncture Tubes containing gels are not used in blood bank or ○ With the bevel up, quickly and smoothly insert the immunologic testing, as the gel may interfere with needle into the vein at approximately a 15 angle the immunologic reactions. and engage the evacuated tube ○ There is no right way or wrong way to hold the needle and adapter for venipuncture. 1 See last page for review on blood collection tube additives. LAGAT | BSMT III 4  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION ○ Be sure to stretch the skin surrounding the insufficient blood flow to the venipuncture site before inserting the needle; this brain will aid in anchoring the vein and will make needle Causes: insertion less painful. ○ Sudden decrease in ○ Never tell patients that they will not feel the blood volume needle puncture or that it will not hurt. ○ Cardiac arrhythmia ○ Traumatic draw as a result of vessel wall injury ○ Hypoglycemia can cause increase CK, myoglobin and ○ Hyperventilation potassium However, fainting is primarily ○ If a phlebotomist accidentally punctured an artery due to psychological causes instead of a vein, he should immediately apply in individuals who are having pressure and report the case to the supervisor. their blood collected To prevent fainting or to deal AFTER PERFORMING VENIPUNCTURE effectively with it, the phlebotomist must always be 6. Releasing the Tourniquet aware of the condition of the ○ Once good blood flow is established and before patient. the final tube is filled, release the tourniquet. Observe the patient before the phlebotomy; is he or she 7. Removing the Needle acting nervous or ○ Once the last tube of blood is filled and you have hyperventilating. Try to engage removed it from the needle and tube holder, you the patient in conversation to may remove the needle. keep his or her mind off the ○ Do this in a single smooth, swift motion, and procedure. After performing quickly apply clean gauze over the puncture site. the venipuncture, ask the ○ If the patient is able, instruct him or her to apply patient how he or she feels. pressure and to keep the arm straight. If the patient feels faint after 8. Needle Disposal the phlebotomy has been ○ Do not lay it down, and do not recap it started, remove the tourniquet, carefully remove 9. Specimen Labeling and Transportation the needle, and, while ○ Immediately label the specimen applying pressure, support the ○ If any specimens require mixing, do so by gently patient and call for help. inverting the tubes several times Never leave the patient. ○ In some hospitals, certain specimens must be hand labeled and initialed by the phlebotomist LATE LOCAL COMPLICATIONS ○ As a responsible phlebotomist, you must be aware of any special transportation requirements Table 7. Late Local Complications 10. Handwashing COMPLICATION DESCRIPTION Is an abnormal vascular Complications of Venipuncture condition in which thrombus Thrombosis develops within a blood vessel of the body IMMEDIATE LOCAL COMPLICATION Is inflammation of a vein often accompanied by clot Table 6. Immediate Local Complications Thrombophlebitis which occurs as a result of COMPLICATION DESCRIPTION trauma to the vessel wall Is an increase in the number Occurs when the needle is of formed elements in blood improperly placed in the vein, resulting either from a Hemoconcentration allowing blood to escape decrease in plasma volume. from the vein and collect Occurs when the tourniquet Hematoma under the skin. is on for too long Primary indication of a Caused by: hematoma is swelling around ○ Excessive pull of the the venipuncture site while plunger Failure of blood the needle is inserted ○ Piercing the other pole to enter the of the vein LATE GENERAL COMPLICATIONS syringe or ETS ○ Incorrect bevel position (bevel down) Serum hepatitis ○ Absence of vacuum AIDS More commonly referred to Syncope as fainting, results from LAGAT | BSMT III 5  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION Causes of Hemolysis (Hemolyzed specimen) For premature infants: ○ because large amount of blood Using a needle that is too small required for repeated Pulling the syringe plunger back too fast venipunctures may cause Expelling the blood vigorously into a tube iatrogenic anemia Forcing the blood from a syringe into an evacuated For sick infants which require tube parenteral therapy: Shaking or mixing the tubes vigorously ○ Accessible veins in sick infants Performing blood collection before the alcohol has must be reserved exclusively for Advantages of dried at the collection site parenteral therapy Skin Puncture For geriatric patients: Causes of hematoma ○ Skin puncture is often preferred in geriatric patients because the The vein is fragile or too small for the needle size skin is thinner and less elastic The needle penetrates all the way through the vein For adults: The needle is partly inserted into the vein ○ useful in adults with extreme The needle is removed while the tourniquet is still on obesity, severe burns, and Excessive probing thrombotic tendencies Pressure is not adequately applied after venipuncture CAPILLARY BLOOD Capillary puncture is the preferred way to obtain blood from infants and very young children for the Skin puncture following reasons: A fingerstick to obtain blood for ○ Infants have a small blood volume routine laboratory analysis is usually ○ Infant or child venipuncture is difficult and can preferred for children older than one damage veins and surrounding tissues year old ○ An infant or child can be injured by the restraining Characteristics Microcapillary blood collections are method used during venipuncture used primarily when the patient has ○ Capillary blood is the preferred specimen for some no adequate veins for venipuncture, tests, such as newborn screening tests either because of age or for some other reason, such as burns or Arterialized Capillary blood dermatitis. It is used for blood gas analysis (newborn and infants) Length of Lancet 1.75 mm for measuring pH and pCO2 but not pO2 The depth of the incision should be Earlobe is the preferred site because of vascularity, ○ < 2.0 mm for infants and low metabolic requirements and ease with which it can children; be arterialized. ○ < 2.5 mm for adults, to avoid Lateral plantar heel surface is the most commonly contact with the bone used site. Incision The cut should be oriented across the fingerprints to generate a large PROCEDURE drop of blood using a single deliberate motion 1. Warm the earlobe or heel surface with a paper towel Wipe away the first drop of blood saturated with warm water, 39-42℃ for 3-5 minutes. 2. Flick the earlobe with the index finger. Lateral plantar heel surface – newborn 3. Cleanse the area with 70% alcohol Sites of Palmar surfaces of the fingers 4. Two heparinized tubes are placed in the center of Collection Plantar surface of the big toe the next drop of blood and filled to capacity without Earlobes air bubbles. Central arch area of an infant’s heel 5. Both ends are sealed in clay after the insertion of flea. Sites not Fingers of a newborn or infant less 6. Blood is stirred using a magnet to draw the flea back generally than one year old and forth across the length of the tube to mix the recommended Thumb, index and fifth fingers specimen completely. Fingers on the side of a mastectomy First to last: REASONS FOR RAPID SEPARATION OF BLOOD Order of Filling ○ EDTA (After centrifugation) Microcollection ○ Other tubes with additives Tubes ○ Non-additive tubes Ideally, all measurement should be performed within 45 minutes to 1 hour after collection LAGAT | BSMT III 6  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION Serum or plasma should be separated from cells Increased levels of the following analytes: as soon as possible, preferably within one hour Adequate time for clotting must be allowed to LDH or Lactate dehydrogenase prevent latent fibrin formation, which may cause ACP or Acid Phosphatase Enzymes undesirable clogging of automated chemistry AST or Aspartate transaminase/ aspartate aminotransferase analyzers Plasma should not remain in contact with the Magnesium cells overnight. Electrolytes Phosphorous Potassium 3000 RCF for 10 minutes is the centrifugation requirement Total protein Reasons to separate Serum/plasma from cells: Albumin Other analytes ○ To prevent glycolysis Cholesterol ○ Certain substances [in blood] are very unstable Iron ○ To prevent shift of electrolytes ○ To prevent hemolysis INTERFERING CONDITIONS IN THE MEASUREMENT OF ANALYTES To prevent glycolysis Most common interfering conditions: 2 mg NaF/ml of blood: prevents glycolytic enzyme or ○ Hemolysis glycolysis for up to 48-72 hours ○ Icterus The use of fluoride-containing tube is not necessary if ○ Lipemia plasma is separated from cells or glucose is measured Hemolysis and icterus strongly absorb specific immediately wavelengths of light Glycolysis occurs faster in newborns because their metabolism is increased, and in patients with leukemia Table 8. Interfering Conditions in Analyte Measurement because of high metabolic activity of WBCs INTERFERENCE DESCRIPTION severe hemolysis causes a Certain Substances Are Very Unstable slight dilutional effect on the Hemolysis analytes present in serum or Hemoconcentration: Due to movement of water into plasma cells after 24 hours, unseparated serum and plasma Serum bilirubin of 25.2 mg/ml yield clinically significant increases in which means icteric specimen, ○ total bilirubin, ○ albumin interferes with the ○ sodium ○ calcium measurement of total protein, ○ urea ○ magnesium albumin, cholesterol and ○ nitrogen ○ total protein glucose Bilirubin Bilirubin in a specimen is not Least stable in serum if not removed from the clot readily removed and so may within 30 minutes: cause spectral interference ○ Potassium through its high absorbance at ○ Phosphorus wavelengths between 340 and ○ Glucose 500 nm Unstable after 6 hours when the serum was not It occurs when serum separated from the clot: triglyceride exceeds 4.6 ○ Albumin ○ HDL-Cholesterol mmol/l (400 mg/dl) ○ Bicarbonate ○ LDL-cholesterol Lipemia It scatters light and eventually ○ Chloride ○ Iron blocks transmission of light ○ C-peptide ○ Total protein Lipemia inhibits amylase, urea, CK, bilirubin and total protein To Prevent Shift Of Electrolytes Corrective measures for artifactual absorbance: This will result to false increase of potassium and blanking technique. subsequent decrease of sodium in serum and plasma To Prevent Hemolysis Effects of Hemolysis Interferes with the color reactions It increases bilirubin levels It inhibits lipase LAGAT | BSMT III 7  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION STORAGE AND TRANSPORT OF SPECIMENS REASONS FOR SPECIMEN REJECTION Serum or plasma must be stored at 4-6℃ if Hemolysis/lipemia analysis is to be delayed for longer than 4 Clots in an anticoagulated tube hours. Non-fasting specimen (If required) LDH 4 and 5 isoenzymes and ALP are affected Wrong blood collection tube Short draws by low temperature storage prior to testing. Improper transport Discrepancies between requisition and specimen label SPECIMEN CONSIDERATION Unlabeled specimen Contaminated specimen/leaking container Specimens that require chilling during transport & storage (4℃): EVACUATED TUBES ○ Ammonia ○ Blood gasses Most of ETS tubes contain additives Temperature- ○ Catecholamines Additive functions optimally – tube filled to its sensitive ○ Gastrin stated volume, gently inverted to mix the additive ○ Lactic acid ○ Renin ○ PTH ADDITIVES ○ Pyruvate Four types of additives in ETS tubes Bilirubin Beta-carotene Prevent blood from clotting Photosensitive Folate Examples: Analytes Porphyrins Anticoagulant ○ EDTA Vitamin A (ECHO) ○ Citrates Vitamin B6 ○ Heparin ○ Oxalate NOTES (TO REMEMBER): Prevents glycolysis 10 mg/dl/hr Antiglycolytic Plasma: medical emergencies Preserves glucose for up to 3 days Increased of substances (proteins and urea) in Combines with potassium oxalate unseparated serum or plasma is also due to Thrombin movement of water into cells resulting to Clot Activator Silica hemoconcentration Thixotropic gel — Rimming the tube should be avoided Potassium (Serum > Plasma) Additive reliability is guaranteed until an expiration date Excessive centrifugation ➔ cell lysis (Elevation of on the label of the tubes is handled and stored potassium and LDH) properly. Insufficient centrifugation: [caused by] incomplete barrier formation in gel tubes or cell contamination Electrolytes are affected by evaporation of NOTE: specimens prior to testing. Specimen quality can be compromised due to: ○ QNS: tube is partially filled. TEN COMMON ERRORS IN SPECIMEN ○ Vigorous mixing COLLECTION 1. Misidentification of Patient ORDER OF DRAW 2. Mislabeling of Specimen 3. Short draws Special sequence of tube collection that reduces 4. Wrong anticoagulant the risk of specimen contamination by 5. Mixing problems/clots microorganisms and additive carry-over. 6. Wrong tubes/Wrong anticoagulant EDTA carry-over causes more problems than that 7. Hemolysis/lipemia 8. Hemoconcentration from prolonged tourniquet of any other additive application Heparin causes the least interference: natural 9. Exposure to light/extreme temperatures 10. Improper timed specimens/delayed delivery to laboratory 11. Processing errors; incomplete centrifugation, improper storage LAGAT | BSMT III 8  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION Table 9. Summarized Order of Draw Without ARD: no turbid bottom ORDER TUBES NOTES Light Blue Top: coagulation studies in Sterile collection L Yellow SPS Hematology Minimizes chance of Blood Culture Red Top and Gold Top Tubes: serum Sterile media microbial bottle contamination samples with same order of draw ○ Red Top Sodium citrate Plastic: 5 inversions Coagulation First additive tube Light Blue Glass: No inversions Tubes (additives affect coagulation test) R ○ Gold Top Serum separator gel (clot No additive activator): 10-20 mins Red Tube Glass Prevents Clots blood to produce serum contamination Same order of draw as red top With clot activator tubes Filled after coagulation test G Green Top Tube because silica L Lavender Top Tube particles activate G Gray Top Tube Serum Tubes Red or Gold clotting Carry over into subsequent tubes can be overridden by PROBLEM SITES anticoagulants Affects coagulation Table 10. Problem Sites for Specimen Collection Plasma Green/light SITE DESCRIPTION Interferes in Separator green Difficult to palpate collection of serum Increase sodium Impaired circulation (Na+) and Burns: potassium (K+) ○ Susceptible to infection EDTA Lavender Chelates calcium Burns, Scars Tattoos: (Ca+) and Tattoos ○ Dyes that can interfere in Increase PT and testing PTT ○ Areas with dye should be Affects sodium avoided unless no other site is (Na+) and available Oxalate or Sclerosed or thrombosed Gray potassium (K+) Fluoride Damaged Hard, cordlike, lacking resilience Damages cell membrane of RBC Veins Difficult to puncture Impaired blood flow Abnormal accumulation of fluid in the tissue RECALL: Order of Draw Mnemonic (MT 12) Edema Difficult to locate Altered blood composition Table 9.1. Routine Order of Draw Mnemonic It is painful SLRGLG Hematoma If no other site is suitable, draw the SPS, Light blue, Red & Gold, Green, Lavender, Gray specimen distal to the hematoma Sterile Samples: ex. Blood culture Lymphostasis: Lymph node bottles removal (Stoppage of lymph flow) SPS: Sodium polyanethol sulfonate Mastectomy Arm is susceptible to swelling and Blood culture bottles (Microbiology) infection ○ Green Adult: 5-10 mL With ARD2 REFERENCES S 8 inversions ○ Orange Notes from the discussion/learning mats by: Pedia: 1-5 mL ALEX JOEY COLOYAN With ARD 8 inversions Silliman University PowerPoint presentation: ○ Yellow Patient Preparation and Specimen Collection With ARD: turbid bottom 2 Antibiotic Removal Device LAGAT | BSMT III 9  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION NOTES (From: Shenikah Tulabing) hyperglycemic hormone ○ Thus, smoking = false increase FBS Glucose Testing (FBS) During fasting, patient must follow NPO (non per ○ Normal: 60-99 mg/dl orem) ○ Pre-diabetic: 100-125 mg/dl Insulin is the only hypoglycemic hormone. ○ Diabetic: > 126 mg/dl Gamma Glutamyl Transferase (GGT) Types of Diabetes Mellitus ○ Increases if there’s obstructive jaundice ○ I: Insulin deficient ○ An enzyme (intracellular) found in the bile ○ II: Insulin resistant duct ○ III: Other specific types of DM ○ If gallstones block the bile duct, cells are ○ IV: Gestational inflamed, releasing GGT Lipids Caused by alcoholism/occult ○ Chylomicron alcoholism ○ HDL & LDL - transport cholesterol (cell Alcoholism membrane fluidity) ○ Liver detoxifies instead of synthesizing ○ VLDL ○ Decreased glucose ○ AOTA are TAGs for energy source ○ Too much leads to cirrhosis which is Cholesterol also produces steroids like hepatotoxic testosterone, estrogen, etc. Liver enzymes The liver produces 70% cholesterol. ○ ALT - SGPT (Alanine Aminotransferase - LDL transports cholesterol from the liver to Serum Glutamate Pyruvate Transaminase) different parts of the body. ○ AST - SGOT (Aspartate Aminotransferase HDL collects cholesterol from body parts and - Glutamic-oxaloacetic Transaminase) transports it to the liver for excretion. Mnemonic: LPG only 3 letters Non-protein Nitrogens (NPNs) present in the ALT - SGPT ○ Creatinine pairing End-product of muscle Situation: Reye’s Syndrome metabolism, forms in creatine ○ Normal dosage of paracetamol: 6g/day ○ Uric acid ○ If excess like 10 g/day, there’s injury to End-product of purine the hepatocytes leading to decreased metabolism detoxification. ○ Ammonia ○ Decreased detoxification = Increased ○ Urea ammonia, leading encephalopathy End-product of protein Diuretics = false decrease of Na+ and K+ metabolism Marker of Acute Myocardial Infarction (AMI) is Protein > amino acid > ammonia Ck-MB > urea Prolonged tourniquet application leads to Tophi - uric acid solidifies; irreversible hemoconcentration and anaerobiosis Gout - increased uric acid; reversible Temp. range of storing blood collection tubes = Creatinine, uric acid and urea assess kidney 4-25 degrees C. function. Arterialized capillary blood Ammonia is to assess liver function. ○ Done via skin puncture Increased cortisol - 8AM (circadian rhythm) ○ Sample mimics arterial blood Ultradian: epinephrine ○ To measure CO2 and pH, not Infradian: estrogen during menstrual cycle recommended for O2 Circannual: level of Vitamin D of people living in Warming of arterialized capillary blood puncture places w/ less sun exposure site: 39-42 degrees C for 3-5 mins pH = HCO3 / CO2 Flea - small metal inside capillary tube before Low CO2 and high pH = respiratory alkalosis sealing to properly mix anticoagulant w/ blood ○ Intervention: breathe through paper bag Enzymes to increase CO2 ○ LD, ACP, and AST are found in RBCs. If FBS there’s hemolysis, values increase. ○ 8-10 hrs (based from institution; must Acid Phosphatase (ASP) is a medico-legal follow SOP) substance. ○ 8-16 hrs (based from book) ○ ASP is from prostate Lipid Panel ○ Case: Rape ○ 10 (usual) to 12 hrs ○ Sample: Vaginal washing Glucose Test ○ If increased ACP, seminal fluid is present ○ Patient smokes = increased cortisol and Lipase and amylase = to diagnose pancreatitis catecholamine ○ Increased lipase = mumps ○ Epinephrine (a catecholamine) is a Chylomicrons not found in plasma 6-9 hrs LAGAT | BSMT III 10  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION post-prandial Icteric = sample is dark yellow to orange ○ Jaundice = increased bilirubin Hemolysis ○ False increase K+ ○ Increased plasma volume due to release of H2O ○ False decrease Na+ ○ Dilutional effect Spectrophotometer = absorbance directly proportional to conc. ○ If sample has bilirubin and is lipemic = result is false increase LD 4 & 5 isoenzymes, and ALP are cold-sensitive ○ Keep only in room temp. ○ Exposure to cold = false decrease Calculating calories ○ Carbs = 1g x 4 ○ Protein = 1g x 4 ○ Fat = 1g x 9 Vitamin B12 is only present in meat. Platelet aggregation ○ Slight increase of K+ as it’s released from the platelets ○ Abundant in serum than in plasma (slightly) ○ Do not use EDTA LAGAT | BSMT III 11  BLOOD TUBE COLLECTION GUIDE: ORDER OF DRAW Table 11. Vacutainer Tube Top Colors CLOTTING SERUM or COLOR ADDITIVE INVERSIONS ASSOCIATED TESTS NOTES TIME PLASMA BLOOD CULTURE Sterile collection; Minimizes chance of microbial contamination SPS for blood culture specimen collections in microbio. In addition to being an anticoagulant, it: Sodium polyanethol Yellow 8 Plasma Blood Culture ○ Reduces the action of complement that destroys sulfonate (SPS) bacteria ○ Slows down phagocytosis ○ Reduces the activity of certain antibiotics ACD for blood bank studies, HLA phenotyping, DNA Immunohematology Acid Citrate Dextrose (ACD) 8 Plasma and paternity testing in immunohematology Tests Prevents coagulation by binding calcium. COAGULATION STUDIES For Hematology CTAD: selected platelet function assays and routine Sodium citrate Light Blue coagulation determination Coagulation tests (PT, Citrate prevents coagulation by chelating (binding) Citrate-theophylline- 3-4 Plasma PTT/APTT) D-dimer calcium. adenosine-dipyridamole Vigorous mixing or an excessive number of inversions (CTAD) can activate platelets and shorten clotting time. COAGULATION TUBES / CLOT ACTIVATORS Sterile collection; Minimizes chance of microbial contamination Serum determination Routine blood donor screening Gold Silica particles (clot activator) Diagnostic testing of serum for infectious diseases Routine Chemistry and + 5 30 mins. Serum Thixothropic gel: Serology tests Thixotropic gel ○ An inert (non-reacting) synthetic substance with a SG of 1.04 initially contained in or near the bottom of certain blood collection tubes. Red Glass (Silicone coated) 0 Routine Chemistry and Sample is allowed to clot first before subjecting to 60 mins. Serum Serology tests centrifugation. Plastic (Silica Particles) 5 Orange Thrombin 5-6 5 mins. Serum Stat serum determinations in CC With serum separator gel Routine Chemistry and Thrombin cleaves fibrinogen into fibrin, forming the Thrombin Serology tests 8 5 mins. Serum “clot.” w/o serum separator  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION ANTICOAGULANTS Prevents blood from clotting by binding or precipitating calcium (chelation), making it unavailable for the coagulation process. Plasma determinations in CC (chemistry) Heparin binds to anti-thrombin in the plasma, inhibiting thrombin and activated coagulation factor 10. Heparinized specimens must be mixed immediately upon collection to prevent clot formation and fibrin Heparin: generation. Light Green or Green Lithium heparin and gel for plasma Osmotic Fragility Testing separation and Blood Gas Analysis Table 11.2. Forms of Heparin Used 8-10 Plasma ADDITIVE DESCRIPTION Lithium heparin STAT Chemistry tests Ammonium Not used for ammonia level Sodium + heparin heparin determinations Causes the least interference in Lithium chemistry testing and is the heparin most widely used anticoagulant Sodium Injectable form used for heparin anticoagulant therapy EDTA removes ionized calcium (iCa or Ca2+) Functions: ○ Preserves cell morphology ○ Inhibits platelet aggregation better than other Glass: Ethylenediamine anticoagulants 8-10 Plasma tetraacetic acid (Liquid EDTA) Table 11.1. Types of EDTA Additives Whole blood hematology TYPE DESCRIPTION tests (CBC, Reticulocyte aka sequestrene Lavender Count, ESR, etc.), Causes sample dilution Routine for 1-2%, resulting in Immunohematology lower values for HGB, LIQUID K3EDTA Testing, Blood donor RBC, WBC, PLT counts screening and packed cell volumes Mixes easily with blood. Plastic: K2EDTA (Spray coated) 8-10 Plasma More soluble than SPRAY- K2EDTA disodium salt and will DRIED not dilute sample Na2EDTA aka versene  TOPIC 1: PATIENT PREPARATION AND SPECIMEN COLLECTION ANTI-GLYCOLYTIC AGENTS Inhibits the metabolism of glucose by blood cells K Oxalate: ○ Preserves glucose for up to 3 days ○ Removes Ca2+ and prevents clotting by binding Potassium oxalate Plasma and precipitating Ca2+ in the form of an insoluble Gray Blood glucose salt (CaOx) determinations and NaFl 5-10 alcohol level ○ Preserves glucose and also inhibits the growth of determinations bacteria ○ Used to collect ethanol specimens to prevent Sodium fluoride (NaFl) Serum either: Decrease in alcohol conc. due to glycolysis Increase due to fermentation by bacteria OTHER COLLECTION TUBES WB hematology determinations Pink Routine immunohematology testing Immunohematology K3EDTA / K2EDTA 8 Plasma Blood donor screening Tests Designed w/ special cross-match label for patient information required by AABB Royal Blue Trace-elements, toxicology, nutritional chemistry K2EDTA 8 Plasma Trace Elements determinations Tan K2EDTA 8 Plasma Lead Determinations Contains