CHAPTER 11 Blood Cultures GGT ABGs and Urine

CHAPTER 11 Blood Cultures, GGT, ABGs, and Urine Samples

Blood Cultures • Collected from patients who have fevers of unknown origin (FUO) • During the course of a bacterial infection, bacteremia or septicemia may result. • Blood cultures aid in identifying the specific bacterial organism causing the infections. Blood Culture Collection • Possible Interfering Factors – Blood culture specimens must be collected first. – Do not scrape the needle across the skin. – Fill anaerobic blood culture vial first except when using the butterfly assembly. – Culture vials with resin beads. Blood Cultures Procedural Steps – Read the manufacturer’s directions about blood culture vials before using them. – Place each bottle on a flat surface and then use a marker to mark a “fill-to line. ”

Safety Syringe Blood Culture Collection • Prepare and assemble supplies. • Identify the patient properly. Briefly explain the test to the patient. • Wash or sanitize your hands with an alcohol hand rinse, then put on gloves. • Locate the vein. • Loosen the tourniquet. • Scrub the site of the venipuncture with 70% isopropyl alcohol for 60 seconds. • Scrub with iodine tincture(chlorhexidine gluconate for patients sensitive to iodine or for infants older than 2 months) for 30 seconds. • Initially place the iodine swab at the site of needle insertion and then move it outward in concentric circles to a diameter of 2. 5 inches. • After the collection of the blood into the syringe, activate the safety-needle cover. • Aseptically dispose of the needle into the sharps container without touching the needle. • Place a blunt-tipped cannula(connector) on the syringe tip and attach the blunt-tipped connector to the directdraw holder/adapter. • Start with the vial labeled “an aerobic microbiology vial” and place it in an upright position. • Place the blood-transfer device on the vial. • Fill to the desired amount. • Remove the syringe with the blood-transfer device from this vial.

Safety Syringe Blood Culture Collection Con’t • Fill the aerobic vial after the an aerobic vial. • Fill other blood collection tubes according to the “order of draw. ” • NEVER push on the syringe plunger. • Allow the vacuum in the microbiology vials to pull the blood into the vials. • If the amount of blood collected is only 3 m. L or less, place the entire amount in the aerobic vial. • For infants and small children, only 1 to 5 m. L of blood can usually be collected for bacterial culture. • Use blood culture bottles that are designed specifically for the pediatric patient. • Discard the syringe, safety blood-transfer device, and needle in the sharps container with biohazard label. • Discard blood-soaked gauze sponges, grossly contaminated items, and gowns or gloves used in isolation rooms in biohazard waste containers. • Dispose of gowns and gloves that are not from isolation rooms in the regular trash. • Wash or sanitize your hands. • Deliver the sample immediately to the laboratory.

Safety Butterfly Assembly—Blood Culture Collection • Prepare and assemble supplies. • Identify the patient properly. • Briefly explain the test to the patient. • Wash or sanitize your hands with an alcohol hand rinse, then put on gloves. • Use a safety butterfly assembly for insertion of the butterfly needle into the venipuncture site after the appropriate skin preparation. • Place a strip of tape over the butterfly wings to keep the needle in place. • Transfer the blood to the microbiology vials via a direct draw adapter that fits directly over the blood culture vial. • Transfer the blood to the aerobic vial first. • Discard the safety butterfly assembly and safety blood-transfer device in the sharps container with biohazard label. • Discard blood-soaked gauze sponges, grossly contaminated items, and gowns or gloves used in isolation rooms in biohazard waste containers. • Dispose of gowns and gloves that are not from isolation rooms in the regular trash. • Wash or sanitize your hands. • Deliver the sample immediately to the laboratory.

After Blood Culture Collection • After collecting the blood, remove the iodine from the patient’s skin. • Initial the patient identification labels, indicate the time and date of collection on the labels, and attach a label to each vial or tube. • Document the: a) date and time specimen obtained and b) site of specimen collection. • Changing needles should not occur.

Glucose Tolerance Test (GTT) • An effective diagnostic tool for patients who have symptoms suggesting problems in carbohydrate metabolism, such as diabetes • Complete Instructions to Patient for Preparation – Eat normal, balanced meals for at least 3 days before the test. – Fast for 8 to 12 hours. – Drink water and not tea, coffee, or other beverages. – Do not smoke, chew tobacco, or chew gum. • Obtain a fasting blood specimen. • If the result is normal, then the patient can be given a standard load of glucose. • Obtain subsequent blood and urine samples at intervals, usually during a 2 to 3 hour period. • Send each specimen to the laboratory for immediate testing. • Venous blood is the preferred specimen. • If serum samples are collected, use the serum separator tube. • The grey-topped tubes have a preservative and can be used for this procedure. metabolism tests(such as a GTT or Hemoglobin A 1 c) areneeded.

• Possible Interfering Factor with GTT – Nausea and vomiting may occur early during the GTT. – If the patient vomits within the first 30 minutes, discontinue the test and reschedule for another day. – If the patient vomits or becomes faint later in the test, have them lie down and complete the testing if possible. • Used to screen patients for diabetes • Patient placed on a high carbohydrate diet 2 to 3 days before the 2 -hour test • The day of the test, the patient should eat a breakfast of orange juice, cereal with sugar, toast, and milk to provide an approximate equivalent of 75 g of glucose. • A blood specimen is taken 2 hours after the patient finishes eating breakfast. • The glucose level is then determined, and the physician can decide whether further carbohydrate metabolism tests(such as a GTT or Hemoglobin A 1 c) are needed.

Point-of-Care Testing • Demand for point-of-care testing(POCT) is increasing because rapid turn around of laboratory test results is necessary. • Other Terms for POCT – Decentralized laboratory testing – On-site testing – Bedside testing – Near-patient testing – Patient-focused testing • Examples of POC Tests – Glucose testing instruments – Hemoglobin A 1 c – Hemoglobin – Influenza A and B – Cholesterol

Obtaining Blood Specimen for Glucose Testing (Skin Puncture) • Gather equipment: safety automatic lancet • Identify the patient properly. Briefly explain the test to the patient. • Clean your hands. • Don gloves. • Select the site and cleanse with antiseptic (especially the side of a finger). • Cleanse skin with alcohol wipe and allow skin to dry. • Gently massage the finger five or six times from base to tip to aid blood flow. • Decide on which side of the finger to make the incision. • Remove the safety lancet from the protective paper, hold the patient’s finger firmly with one hand, make a swift, deep puncture with the retractable safety puncture device. • Wipe the first three drops of blood away with clean gauze. • Gently massage the finger from base to tip to obtain the needed drop of blood. Do not squeeze the fingertip. • Apply the test strip to the drop of blood. • The correct volume is drawn into the cuvette by capillary action • Wipe off any excess blood from the sides of the cuvette. • The laboratory test result is displayed automatically. • Discard the safety automatic lancet in the sharps container with biohazard label. • Discard the gauze, alcohol wipes, and gloves in biohazard waste containers. • Wash or sanitize your hands.

Quality in Point-of-Care Testing(POCT) • Instruments calibrated with glucose standards • Values monitored with quality control material • Electronic quality control (EQC) to test electronics Control material should be analyzed so that the mean and standard deviation can be calculated. • Calculations on 20 to 30 control values. • The control value is plotted on a chart under the appropriate date, and the daily plots are joined with a straight line. • Reproducibility of the Results – Purchasing the reagent strips and controls in quantities to enable healthcare workers to use constant pools of the same lot number. – Preventive maintenance of each instrument is critical for accurate results.

Blood Coagulation Monitoring • Provides immediate results used in monitoring bleeding or clotting disorders in patients • Coagu. Chek XS System – Used to monitor long-term anticoagulation therapy – Immediate test results allow rapid dose adjustments – Calibrated to use the first drop of blood in skin puncture • Instrument to Monitor Anticoagulation Therapy during Cardiac Procedures and Dialysis: – Actalyke XL Activated Clotting Time Test(ACT) System • The INRatio 2 Meter is used to measure prothrombin time (PT)INR for maintenance of proper anticoagulation therapy. Hematocrit, Hemoglobin, and Other Hematology Parameters • Hematocrit (Hct, packed cell volume[PCV], or Crit) – Represents the volume of circulating blood that is occupied by red blood cells(RBCs) – It is expressed as a percentage. – Values are obtained to aid in the diagnosis and evaluation of anemia. – Blood collection usually occurs by skin puncture. – Plastic micro capillary tubes are used. • Hemoglobin Test – Aids in the diagnosis and evaluation of anemia and other blood abnormalities – More accurate than hematocrit test – Safer method to detect anemia

Cannulas and Fistulas • A cannula is a tubular instrument that is used in patients with kidney disease to gain access to venous blood for dialysis or blood collection. • Blood should be collected only by specially trained personnel, because the procedure requires special techniques and experience. • A fistula is an artificial shunt in which the vein and artery have been fused through surgery. • Only specialized personnel can collect blood from a fistula. • Use extreme caution and avoid using the arm with fistula.

Donor Room Collections • Donor Interview and Selection – Date and time of donation – Name – last, first, and middle initial – Address – Telephone number – Gender – Age and date of birth –Written consent form signed by the donor – A record of reasons for deferrals, if any – Social security number or driver’s license number – Name of patient or group to be credited – Race (not mandatory) – Unique characteristics about a donor’s blood

Donor Room Collections • Donor Interview and Selection Con’t • Brief Physical Examination –Weight – Temperature – Pulse – Blood pressure – Skin lesions – General appearance – Hematocrit or hemoglobin values – Extensive medical history • Collection of Donor’s Blood – Blood should be collected by using aseptic technique; a sterile, closed system; and a single venipuncture. – The health care worker should be well versed in donor reactions, equipment safety precautions, first-aid techniques, and location of first-aid equipment incase it is needed in the course of donation. • Therapeutic Bleeding – Blood obtained through therapeutic bleeding may be used for homologous transfusion if the unit is deemed suitable by the director of the blood bank. – The recipient’s physician must agree to use the blood from his/her patient. – Keep a record of the agreement. – The label must indicate that the blood is the result of a therapeutic bleed and must include the patient’s diagnosis.

Arterial Blood Gases • Provide useful information about the respiratory status and the acid–base balance of patients with pulmonary(lung) disease or disorders. • Arterial blood is used rather than venous blood. • Radial Artery Puncture Site – Located on the thumb side of the wrist. Arterial Blood Gases • Brachial Artery Puncture Site – An alternative site for blood collection for ABG analysis – Located in the cubital fossa of the arm • Femoral Artery Site – Located in the groin area of the leg, lateral to the femur bone – Lacks collateral circulation – Choice of site for patients with cardiovascular disorders – Last choice of site for an arterial puncture

Radial ABG Procedure • Gather and organize the necessary equipment and supplies. • Properly identify and inform the patient of the arterial puncture procedure. • Determine that the patient has been in a stable state for at least the previous 30 minutes. • Attempt to calm the patient before collecting the specimen if the patient appears anxious. • Before proceeding, determine if patient is on anticoagulant therapy, or allergic to iodine or lidocaine. • Record the patient’s temperature, oxygen concentration, and respiratory rate. • Wash your hands, put on gloves, a facial mask, and a protective laboratory coat and palpate the radial artery in the forearm. • The radial artery in the patient’s non dominant hand is usually the best choice. • With the forefinger or first two fingers, press at this site to find the artery. • Never use thumb for palpating because there is a pulse in the thumb that may be confused with the patient’s pulse. • Avoid any site that has a hematoma or that was previously used for an arterial puncture. • Position the patient’s arm with the wrist slightly extended and rotated. • Check for adequate collateral circulation using the modified Allen test.

Modified Allen Test • Perform before using the radial artery for blood collection for ABG analysis • Makes certain that the ulnar and radial arteries are providing collateral circulation • Compress both arteries with your index and middle fingers, and ask the patient to tightly clench his/her fist. • Ask the patient to open his/her hand, and release the pressure on the ulnar artery. • The Allen test is positive when hand fills with blood within 5 to 10 seconds. • If color does not return to the hand after 5 to 10 seconds, the Allen test is negative. • A negative Allen test indicates the inability of the ulnar artery to supply blood to the hand adequately and shows a lack of collateral circulation. • The radial artery should not be used in a negative Allen test.

Radial ABG Procedure • Once the radial artery site is chosen, clean the area well with tincture of iodine. • If a local anesthetic is desired by the patient – Fill a 1 m. L syringe with lidocaine. – Inject the lidocaine with the 25 - to 26 -gauge needle subcutaneously around the anticipated puncture site. • No tourniquet is required because the artery has its own strong blood pressure. • Use a prefilled heparinized safety syringe (1 to 5 m. L) with a needle to withdraw the sample. • Hold the syringe or collection device in one hand as one would hold a dart. • Pull the skin taut with a finger of the other hand over the artery and pierce the pulsating artery at a high angle, usually an angle of 30 to 45 degrees against the blood stream. • Little or no suction is needed, because the blood pulsates and flows quickly into the syringe under its own pressure. • Completing Arterial Blood Gas Collection. • When approximately 1 m. L of blood is collected, withdraw the needle carefully to avoid introducing bubbles into the syringe. • Apply gauze and direct manual pressure on the site for at least 5 minutes. • Engage the safety syringe cover to cover the needle exposure. • Gently mix the blood in the syringe with the heparin and label the syringe. • Mix the blood gently by inverting the syringe at least 5 minutes. • Before leaving the patient, clean the puncture site with an alcohol pad to remove the excess iodine solution; leave a pressure bandage on. • If bleeding from the site persists, apply more manual pressure and ring for assistance from the patient’s primary nurse. • Never leave a patient who is bleeding, particularly after an arterial puncture. • Notify the primary nurse after an arterial puncture is performed so that the area may be checked frequently for deep or superficial bleeding. • Ideally, the specimen should be analyzed within 10 minutes of collection. • Transport the specimen immediately to the laboratory. • Discard the syringe and needle in the sharps container with biohazard label. • Discard blood-soaked gauze, grossly contaminated items, and gowns or gloves used in isolation rooms in biohazard waste containers. • Dispose of gowns and gloves that are not from isolation rooms in the regular trash. • Wash or sanitize your hands.

Urine Collections • Collecting and transporting urine and other body fluid specimens • Many of the body fluids are difficult to obtain. • The quality of the test result is only as good as the specimen that is collected. • Adhere to standard precautions. • The laboratory request slip must accompany the specimen. • Labels Must Include – The patient’s name – The patient’s identification number – The date – The time of collection – The type of specimen – The attending physician’s name • The label should be affixed on the container, not on the lid.

• Routine Urinalysis (UA) – Includes a physical, chemical, and sometimes microscopic analysis of the urine sample – The physical properties include color, transparency vs. cloudiness, odor, and concentration as detected through a specific gravity measurement. • Chemical Analysis – Determined by using plastic reagent strips impregnated with color-reacting substances that test for the presence of glucose, protein, blood (red blood cells[RBCs] and hemoglobin), white blood cells (WBCs), ketones, bacteria, bilirubin, and other constituents • Single Specimen Collection – The preferred urine specimen for most analyses is the first voided urine of the morning, when urine is the most concentrated. – The specimen should be transported to the UA section promptly for analysis within two hours after the patient voids. – If transportation or analysis cannot occur within this time period, the urine should be refrigerated. • Urine Culture and Sensitivity (C&S) – Clean-catch midstream urine collection – The patient is instructed to void approximately one half of the urine in tothe toilet, collect a portion in a readily available sterile container, and allow the rest to pass into the toilet. – Used to detect the presence or absence of infecting organisms – Transport to the microbiology section promptly. • Timed Collections – For creatinine clearance tests, protein and hormone studies, 24 -hour (or other timed period) urine specimens must be obtained. – Be aware of the protocol for collecting a 24 -hour urine specimen to be able to assist with the prevention of collection errors.

Collecting a 24 -Hour Urine Specimen • Explain the whole procedure to the patient and also provide written directions. • Explain the importance of hand washing for the urine collection. • Give the patient the container and lid. • Add any required preservatives to the container before giving it to the patient. • Write the preservative and any precautions on the collection container label. • Place the label on the container, not on the lid. • Include the Following Information on the Label: – Patient’s name – Patient’s identification number – Starting collection date and time – Ending collection date and time – Name of the requested laboratory test • Instruct the patient verbally. • Give them written instructions that the collection of the 24 -hour urine specimen begins with emptying the bladder and discarding the first urine passed. • This first step in the collection process should start between 6 and 8 a. m. • The exact time should be written on the container label. • Except for the first urine discarded, all urine should be collected during the next 24 -hour period. • Remind the patient to urinate at the end of the collection period and to include this urine in the 24 -hourcollection. • Tell the patient to urinate before having a bowel movement • Instruct the patient to refrigerate the entire specimen after adding each collection during the 24 -hour period. • Warn the patient of any preservatives in the container. • Inform the patient not to add anything except urine to the container and not to discard any urine during the collection period. • A normal intake of fluids during the collection period is desirable unless otherwise indicated by the physician. • Some laboratory assays require special dietary restrictions; give these instructions to the patient. • If possible, discontinue medications for 48 to 72 hours prior to urine collection. • Transport the 24 -hour urine specimen to the clinical laboratory as soon as possible. • Place the specimen in an insulated bag or a portable cooler to maintain their cool temperature.