Blood Specimen Collection: Blood Cultures (Home Health Care) - CE/NCPD

ALERT

Signs of nerve injury include severe, unusual, or shooting pain, tingling or numbness, or a tremor in the arm. If the patient complains of any of these symptoms during venipuncture, withdraw the needle immediately.^{undefined#ref16">16}

Take precautions with a patient who takes medications that increase the risk for bleeding.¹³

Draw specimens for a blood culture before administering antibiotics.

Don appropriate personal protective equipment (PPE) based on the patient’s signs and symptoms and indications for isolation precautions.

OVERVIEW

A blood culture specimen set requires that 20 to 30 ml of blood be obtained at one time from one location.¹ Blood culture specimens should be drawn when the patient is experiencing signs and symptoms of bloodstream infection, including fever or chills, and before the administration of antibiotics to increase the likelihood of obtaining a true-positive result. If the patient has been receiving antibiotics at the time the blood cultures are obtained, the laboratory should be notified because an additive can be applied to the blood culture medium to negate the antibiotic’s effect.¹⁵ Typically, two sets of blood cultures are ordered, and each set (Figure 1) contains one aerobic bottle and one anaerobic bottle. Orders regarding the spacing of the specimens may vary among practitioners and organizations.

In some instances, blood culture specimens from a central vascular access device (CVAD) may be ordered. A CVAD specimen should be used only when a central line–associated bloodstream infection (CLABSI) is suspected.¹¹ When a CLABSI is suspected, one set of specimens should be obtained via venipuncture and the other set should be obtained through the distal lumen of the CVAD suspected of being infected.^8,11 When venipuncture is not possible, two blood specimens may be collected through different lumens of the same CVAD, if they are available. The specimen bottles should be appropriately marked to reflect the sites from which the specimens were obtained.

Drawing at least two culture specimens from two different sites helps to distinguish between skin contamination and a true CLABSI.¹⁵ A CLABSI is confirmed when both cultures grow the same infectious organism. When only one of the cultures grows bacteria, the likely cause is contamination, not a true CLABSI.¹⁵

Blood culture specimens are usually drawn using either a needle and syringe or a vacuum-extraction collection system that draws blood into vacuum-sealed blood culture bottles. In both cases, a hollow-bore needle is inserted into the lumen of a patient’s vein to obtain the blood culture specimen. Straight needles from vacuum-extraction collection systems are not used with blood culture bottles. Instead, winged-butterfly needles with a short length of tubing may be approved by the organization for use. Caution should be taken to avoid contaminating the patient’s skin or equipment to minimize the risk of false-positive test results, which can lead to inappropriate antibiotic use. False-positive results may expose patients to additional laboratory tests and increased length of stay.

The correct amount of blood required by the laboratory must be extracted into each blood culture bottle to ensure accurate test results and decrease the patient’s risk of anemia.¹¹ If more than one blood specimen is to be drawn during a single venipuncture, specimens for blood cultures should be drawn first to maintain asepsis and prevent contamination with additives from laboratory tubes.

Because limited venous access may be a life-threatening complication of venipuncture, maintaining the patient’s vein’s integrity is essential. A patient with veins that may collapse or become injured from the vacuum or a patient whose veins may be difficult to locate because of unusual anatomy, trauma from repeated phlebotomy, or edema may also require an alternative method of blood specimen collection.

Tourniquets should be used with caution. If a tourniquet is deemed necessary, the nurse should apply one for no longer than 1 minute to obtain valid results.¹¹ Prolonged tourniquet application can cause stasis and hemoconcentration.¹¹ Infection control standards require that tourniquets be single use.⁵ Staphylococcus aureus contamination from reused tourniquets is a common finding.¹⁸

Venipuncture can be painful, and the patient may experience anxiety or fear before the procedure. In some cases, just the appearance of a needle is frightening. A calm approach and skilled technique may help limit the patient’s aversion to venipuncture. Anxiety may be eased by communicating with the patient about how to help relieve the patient’s concerns.

SUPPLIES

See Supplies tab at the top of the page.

EDUCATION

Provide developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, and overall neurologic and psychosocial state.
Explain the purpose of collecting the blood specimen and the method to be used.
Explain how a tourniquet, antiseptic swab, and venipuncture may feel.
Explain that pressure is applied to the venipuncture site briefly after the needle is withdrawn, without bending the patient’s arm.
- Explain that the patient may apply pressure if able.
- For a patient who has a bleeding disorder or is undergoing anticoagulant therapy, explain that pressure may have to be applied for a longer period of time to achieve clotting.
Teach the patient the signs and symptoms of recurrent bleeding (e.g., expanding hematoma at the venipuncture site) and provide instructions on when to seek additional care.
Encourage questions and answer them as they arise.

PROCEDURE

Perform hand hygiene. Don appropriate PPE based on the patient’s need for isolation precautions or the risk for exposure to bodily fluids.
Introduce yourself to the patient, family, and caregivers.
Verify the correct patient using two identifiers.
Explain the procedure to the patient, family, and caregivers and ensure that the patient agrees to treatment.
Verify the practitioner’s order and assess the patient for pain.
Prepare an area in a clean, convenient location and assemble the necessary supplies.
Review the patient’s electronic health record for medical history and the practitioner’s orders.
1. Review the patient’s history for risks associated with venipuncture, such as anemia, anticoagulant therapy, low platelet count, a bleeding disorder, venous collapse, traumatic venipuncture, or phlebitis.
2. Review the patient’s history for contraindications for specific venipuncture sites, such as an IV access site; potential site on the arm on the side of a mastectomy or other lymphatic system compromise; a site affected by radiation, tissue injury, or infection; a site on the arm on the side affected by a stroke; a current or planned hemodialysis arteriovenous fistula shunt.⁸
  Rationale: Drawing blood specimens from such sites can result in false test results or may injure the patient.
3. Review the practitioner’s orders for the number of blood culture specimen sets to be drawn and the time required between the venipuncture for each set and any additional laboratory test required during venipuncture and compare them with the laboratory requisitions and labels.
4. Review the patient’s history for any allergy or sensitivity to antiseptic solutions,⁵ adhesives, and dressings.¹²
Review other resources as needed.
1. Review the anatomy of the venous system and the organization’s practice for the preferred veins for venipuncture.
2. Review the manufacturer’s instructions for using a blood culture vacuum-extraction system or a syringe and needle for the collection. If drawing blood from a central line, review the manufacturer’s instructions for the CVAD, including the connector caps, proper syringe size for flushing and aspiration, and port clamping.
3. Identify whether precautions or preconditions must be met before the blood cultures can be collected. Specimen timing can be affected by medication administration, nutritional intake, procedures, or diagnostic testing.
4. Identify the appropriate laboratory culture tubes and bottles and validate the sequence in which the blood specimens are to be collected (if multiple specimens are required) and the volume required for each test with the laboratory.⁸
Gather supplies and equipment, including specimen labels, blood culture bottles, and vascular visualization devices, if required, and bring them to the patient’s side.
1. Ensure that all equipment has been cleaned and disinfected using an Environmental Protection Agency (EPA)–registered disinfectant per the organization’s practice.
2. Ensure that all work surfaces used to hold blood specimen collection equipment, including chair arm extensions and tables, have been disinfected to protect the patient and the blood specimen from contamination.¹⁸
3. Ensure that the blood collection tubes’ expiration dates have not passed and that all equipment, bottles, and tubes are intact and free from defects or compromises.
4. Ensure that the blood collection tubes have been stored upright and at the correct temperature (e.g., tubes with some fixative agents require refrigeration).¹⁵
5. Do not preassemble devices before patient identification.
6. Ensure that devices for the blood specimen collection process are from the same manufacturer.
Evaluate the patient for signs and symptoms of bacteremia, including fever and chills, before drawing blood cultures.
Rationale: Three blood culture samples should be drawn at least 1 hour apart beginning at the earliest signs of sepsis.¹⁵
Determine whether antibiotics have been administered before specimen collection and inform the practitioner and laboratory of the time of antibiotic administration. If cultures are needed while the patient is receiving antibiotic therapy, obtain the specimen shortly before the next antibiotic dose.
Rationale: Resin can be added to the culture medium to negate the antibiotic effect.
Determine the patient’s ability to cooperate with the procedure and the patient’s experience with blood specimen collection (e.g., anxiety or fear related to venipuncture).
Review the patient’s history of venipunctures and ask about signs of adverse responses to previous venipunctures, including a vagal response.
Assess the patient for anxiety or fear related to the procedure. Provide reassurance and inquire about how to provide comfort.¹⁸
Assess the need to apply a local anesthetic to reduce pain from the venipuncture, per the organization’s practice.
Determine the patient’s hydration and perfusion status.
Ensure that the lighting is appropriate for observing vein contours and colors.
Raise or lower the bed or chair, if possible, to a comfortable working height to prevent injury.
Assist the patient to a comfortable supine¹⁸ or low-recumbent position and have the patient remove gum, mints, or food from the mouth and discard in a trash receptacle.
Rationale: A low, supported position and an empty mouth reduce the risk of injury if the patient experiences lightheadedness, faints from vagal stimulation, or experiences a seizure.

Be prepared to manage a venipuncture-associated vasovagal reaction for an at-risk patient.

Blood Culture Collection via Venipuncture

Perform hand hygiene and don gloves. Don additional PPE based on the patient’s need for isolation precautions or the risk of exposure to bodily fluids.
At the patient’s side, prepare or compare laboratory requisitions and computer-generated labels (if available). Compare the labels with the patient’s self-identification (per the organization’s practice) by having the patient confirm the spelling of the patient’s full name and date of birth (when possible).
Do not draw blood if there is a discrepancy between the laboratory requisitions or labels and the patient’s identity.
1. Blood culture sets are usually drawn in immediate succession.
2. Blood specimens should be obtained from different peripheral sites.¹⁵
Indicate the volume of blood needed for each test on the label on each bottle. The amount of blood needed for the most accurate analysis is 10 ml for each bottle.⁸
Support the patient’s arm and extend it to form a straight line from the shoulder to the wrist. Place a small pillow or towel under the upper arm or place the arm on the arm rest of the chair or on a table.
Rationale: Correct patient positioning helps stabilize the extremity.
Place a clean towel or paper drape under the patient’s arm.¹⁸
Identify the best sites for venipuncture per the organization’s practice, avoiding contraindicated sites.⁴
1. Choose a vein that is easily visible without applying a tourniquet.
  1. If IV fluid is being administered in one arm, choose a site on the opposite arm for blood specimen collection. If unable to locate a site on the arm opposite an IV infusion site, reevaluate for a venipuncture site distal to the IV infusion site.
    Consult with the practitioner about stopping the IV infusion 30 seconds to 2 minutes before obtaining the blood specimen (as applicable).⁸
  2. Choose a vein that is straight and does not divert into another branch;¹⁸ that has no swelling, hematoma, phlebitis, infection, or infiltration; and that has not had recent venous access or venipuncture. Typically, the median cubital vein is the easiest to puncture because it lies between the muscles (Figure 2).¹⁸
2. If needed, apply a single-use tourniquet proximal to and four to five finger widths from the insertion site.¹⁸ If the venipuncture site will be on the same arm as an IV infusion site, place the tourniquet between the IV infusion site and the intended venipuncture site.
  Rationale: A tourniquet blocks venous return to the heart from the extremity, causing the veins to dilate for easier access.
  1. Encircle the patient’s arm and pull one end of the tourniquet tightly over the other, looping one end under the other (Figure 3) (Figure 4).
    Avoid using a tourniquet for a patient who has a history of bleeding, is easily bruised, has fragile skin, or has diminished circulation; however, if a tourniquet must be used, apply it loosely.
  2. Apply the tourniquet so it can be removed by pulling one end with a single motion.
    Do not keep the tourniquet on the patient longer than 1 minute⁸ before the procedure is performed. Prolonged tourniquet application causes stasis, hemolysis, and hemoconcentration because of changes in the vascular endothelium from increased venous pressure and hypoxia.⁸
3. Palpate the selected vein for firmness and rebound (Figure 5).
  Rationale: A patent, healthy vein is elastic and rebounds on palpation. A thrombosed vein is rigid, rolls easily, and is difficult to puncture.¹⁸
  
  Do not use a vein that feels rigid or cordlike or one that rolls when palpated.
4. If the selected vein cannot be palpated or viewed easily, apply a warm compress over the arm for several minutes per the organization’s practice. If a tourniquet was deemed necessary, remove it and apply a warm compress for several minutes and then reapply the tourniquet.
  Rationale: Warming enhances blood flow, making veins more prominent.
5. Quickly inspect the vein distal to the tourniquet to confirm the selected venipuncture site.
6. Release the tourniquet.
Apply a topical anesthetic, as prescribed or per the organization’s practice, to reduce the patient’s pain, as needed. Remove the anesthetic completely from the patient’s skin after the prescribed dwell time.
Remove gloves, perform hand hygiene, and don clean gloves.
Prepare the blood specimen collection equipment using blood collection bottles, holders, needles, syringes, and transfer devices from the same system and manufacturer to prevent equipment incompatibility.
Rationale: Combining different manufacturers or systems for blood specimen collection equipment may cause injury to the patient or yield incorrect test results. Incompatibility of components may cause failure of the process.
1. Choose an appropriate-size needle that is small enough to fit in the vein but will accommodate the prescribed therapy and patient need.³
  1. Adults: 20 G to 24 G³
  2. Older adults and patients with limited venous access options: 22 G to 26 G³
    Rationale: Needles that are 22 G or smaller minimize insertion-related trauma to the vein.³
2. Ensure a double-ended straight needle or winged-butterfly needle with tubing and a safety device is securely attached to the vacuum-extraction system collection barrel.¹⁸ Alternatively, and if required, remove the sterile cap from the rubber sheathed end of the double-ended straight or winged-butterfly needle and attach the needle to the collection barrel. If a single-ended or winged-butterfly needle is used, attach the needle securely to a collection barrel housing a sheathed needle.
  Rationale: Safety devices can decrease the risk of needlestick injury by 75%.¹⁸
  
  Vacuum-extraction system sheathed needles are considered sharps that are associated with needlestick injuries, and they must be disposed of in a sharps container that is within arm’s reach and is large enough to allow disposal of the entire device without detaching the needle.¹⁸ The flexible cover of the sheathed needle prevents blood from flowing when the needle is not engaged in a vacuum tube; however, the sheath does not prevent a needlestick injury if a finger inadvertently enters the collection barrel.
  
  Use a new collection barrel for each patient. Do not detach the needle from the collection barrel for disposal after use.¹⁸
  
  Keep the needle hub and the connection sites sterile.
3. If using a vacuum-extraction system, position the culture bottles securely, upright, and close enough to the venipuncture site so that the tubing connected to the needle reaches from the selected vein to the upright culture bottle. Place the collection barrel over each culture bottle. Wait to puncture the rubber stopper with the sheathed needle.
  Rationale: Puncturing the stopper before the needle is in the vein causes the culture bottles to lose its vacuum.
  
  Do not contaminate the top of the bottle after it is prepared with alcohol.
4. If using a winged-butterfly or straight needle attached to a syringe, position the culture bottles securely upright and place a sterile transfer device housing a rubber-sheathed needle within reach.
  Rationale: The rubber-sheathed needle housed in the collection barrel is used to puncture the rubber top of the vacuum bottle. When the rubber top is punctured, the vacuum in the bottle extracts blood from the syringe.
  
  Do not contaminate the transfer device or the top of the bottle after it is prepared with alcohol.
Relocate the selected venipuncture site.
Prepare the venipuncture site.
1. Cleanse the skin with alcohol, then allow to dry completely.²
2. Prepare the insertion site with greater than 0.5% chlorhexidine in alcohol solution, using a back-and- forth motion for a minimum of 30 seconds, and allow to dry completely.¹
  Do not touch the site after preparation unless sterile gloves are worn.
Disinfect bottle tops with 70% isopropyl alcohol (i.e., alcohol pad) and allow to dry completely.²
Obtain the blood culture specimens.
1. Relocate the selected venipuncture site. If a tourniquet is deemed necessary, reapply the tourniquet and locate the selected vein.
2. Remove the cap from the venipuncture needle, maintaining the needle’s sterility. Inform the patient to expect to feel a stick.
  If contamination occurs, discard the needle and the collection barrel or syringe in a sharps container and prepare a new venipuncture set.
3. Place the thumb or forefinger of the nondominant hand distal to the venipuncture site and gently stretch the patient’s skin distal to the patient until it is taut and the vein is stabilized.
  Rationale: Gently stretching the patient’s skin helps stabilize the vein and prevent rolling during needle insertion.
4. Hold a butterfly needle (if used) by its wings; hold a straight needle (if used) at the hub. Insert the needle at a slight angle with the bevel up, just distal to the selected site.²
  Rationale: The smallest and sharpest point of the needle should puncture the skin first to reduce the chance of penetrating the sides of the vein. Keeping the bevel up causes less trauma to the vein. Entering the skin distal to the vein prevents unanticipated vein puncture, which may result in inadequate blood specimen retrieval and hematoma.
5. Slowly insert the needle into the patient’s vein (Figure 6). If using a butterfly needle, look for blood return in the tubing of the butterfly setup.
  Rationale: Inserting the needle slowly prevents puncture through the opposite side of the vein.
  
  To avoid false-positive results when obtaining blood cultures via a venipuncture, discard a volume of blood, per the organization’s practice, before filling the blood culture bottles.⁸
Transfer the blood specimen into the culture bottles.
1. Butterfly-winged needle device method
  1. Place a safety device on the syringe and distribute the blood volume evenly between the two culture bottles. Ensure 10 ml for each bottle.⁸
    1. Fill the culture bottles in order per the organization’s practice.
      Do not underfill or overfill the culture bottles because this can adversely affect the laboratory test results.
    2. Without dislodging the needle from the patient’s vein, push the attached collection barrel onto the prepared aerobic culture bottle by inserting the sheathed needle through the rubber stopper so the vacuum pulls the blood into the bottle. Collect 10 ml of blood into the aerobic bottle.⁸
      Observe the rapid flow of blood into the bottle. Failure of blood to appear indicates that the vacuum is lost or the needle is not in the vein.
      
      Avoid overfilling the culture bottle, which may cause a false-positive result.
    3. Detach the collection barrel and insert the sheathed needle through the rubber stopper of the prepared culture bottle. Ensure that the culture bottle receives 10 ml of blood.⁸
      If an insufficient amount of blood is drawn, inoculate the aerobic culture bottle with the required amount and then inoculate the anaerobic culture bottle with the remaining volume of blood.¹⁵
  2. Detach the collection barrel after the culture bottle is filled with 10 ml.⁸
  3. If additional blood specimens are required for other laboratory tests, insert additional blood collection tubes into the collection barrel and engage the sheathed needle. If the tubes contain additives, gently invert them back and forth immediately after they are filled with blood. Follow the manufacturer’s instructions for the number of inversions.
    Rationale: Inverting the blood collection tube gently ensures that the additives are properly mixed and prevents erroneous test results.
    
    Do not shake the blood collection tube.
    
    Rationale: Shaking the blood collection tube may cause lysis of cells, resulting in inaccurate test results.
  4. If the blood is flowing sufficiently into the blood culture bottles or tubes and a tourniquet was used, release the tourniquet just before filling the last blood collection tube. If blood flow is slow, and a tourniquet was used, wait to release the tourniquet until the last bottle or tube is almost full. Fill the last tube and remove it from the collection barrel.
    Rationale: Releasing the tourniquet before filling the last blood specimen tube reduces bleeding at the site when the needle is withdrawn.
  5. Apply a sterile 2 × 2-inch gauze pad over the venipuncture site without applying pressure. Quickly but carefully withdraw the needle from the patient’s vein, activating the safety mechanism to prevent an accidental needlestick injury.⁴
    Rationale: Applying pressure over the needle can cause discomfort and injury to the patient. Carefully removing the needle minimizes discomfort and vein trauma.
  6. Immediately apply pressure over the venipuncture site with gauze until bleeding stops. Observe the site for hematoma or bleeding. Instruct the patient to help apply pressure if the patient is able.
    Rationale: Direct pressure minimizes bleeding and prevents hematoma formation. A hematoma may cause compression and nerve injury.
    
    For a patient who has a bleeding disorder or who is undergoing anticoagulant therapy, hold pressure for several minutes, as needed, until the bleeding stops.
  7. Observe the venipuncture site for bleeding before applying tape or a bandage. Use tape or a bandage to secure the gauze pad in place.
    Rationale: Applying gauze with tape or a bandage keeps the venipuncture site clean and controls oozing.
    
    Instruct the patient not to bend the arm of the venipuncture site.
2. Needle and syringe method
  To avoid false-positive results when obtaining blood cultures via a venipuncture, discard a volume of blood, per the organization’s practice, before filling the blood culture bottles.⁸
  1. Gently aspirate 16 to 20 ml¹⁷ of blood from the venipuncture site into an appropriate-size syringe, ensuring 10 ml for each blood culture bottle (Figure 7).⁸
    Carefully evaluate the patient for the potential for venous collapse when using a syringe barrel that is 10 ml or larger.¹⁸ Consider that some older adults and those who have received treatments damaging to the veins may not be able to withstand high pressure or may require a smaller syringe barrel.
  2. If the blood is flowing sufficiently into the blood culture bottle or syringe, and a tourniquet was used, release the tourniquet just before filling the bottle or syringe.
    Rationale: Releasing the tourniquet before drawing the last of the blood reduces bleeding at the site when the needle is withdrawn.
  3. Apply a sterile 2 × 2-inch gauze pad over the venipuncture site without applying pressure. Quickly but carefully withdraw the needle from the vein, activating the safety mechanism to prevent an accidental needlestick injury.
    Rationale: Applying pressure over the needle can cause discomfort and injury to the patient. Carefully removing the needle minimizes discomfort and vein trauma.
  4. Immediately apply pressure over the venipuncture site with the gauze pad until the bleeding stops (Figure 8). Observe the site for hematoma or bleeding. Instruct the patient to help apply pressure if the patient is able.
    Rationale: Direct pressure minimizes bleeding and prevents hematoma formation. A hematoma may cause compression and nerve injury.
    
    For a patient who has a bleeding disorder or who is undergoing anticoagulant therapy, hold pressure for several minutes, as needed, until the bleeding stops.
  5. Observe the venipuncture site for bleeding before applying tape or a bandage. Use tape or a bandage to secure the gauze pad in place.
    Rationale: Applying gauze with tape or a bandage keeps the venipuncture site clean and controls oozing.
    
    Instruct the patient not to bend the arm of the venipuncture site.
  6. Distribute the blood volume evenly between the culture bottles without replacing the needle.² If both anerobic and aerobic samples are needed, fill the culture bottles in order per the organization’s practice.
    1. Keep the bottle and syringe upright and inoculate the anaerobic bottle, ensuring that no air is transferred from the syringe into the bottle.
      After skin antisepsis, the volume of cultured blood is the next most important variable affecting the sensitivity of detection of bacteria and fungi in the blood.
    2. Inoculate the culture bottle with 10 ml for the most accurate results.⁸
Immediately discard the remaining sharps devices, including the collection barrel and transfer device, into an easily accessible sharps container.
Rationale: Transfer devices and sheathed needles are considered sharps that are associated with needlestick injuries, and they must be disposed of in a sharps container. The sheathed needle’s flexible cover prevents blood from flowing when the needle is not engaged in a vacuum tube; however, the sheath does not prevent a needlestick injury if a finger inadvertently enters the collection barrel.¹⁴

Do not recap needles or attempt to remove the needle from the collection barrel.¹⁴
Repeat the blood specimen collection sequence for a second set. Blood culture sets are usually drawn in immediate succession.
Rationale: Unless ordered by the practitioner or per the laboratory’s practice, blood culture specimens should be obtained from at least two separate blood draws from two separate peripheral sites.⁸
Gently mix the culture broth and blood in the culture bottles.
Rationale: Mixing gently blends the medium and the blood.
Examine the culture bottles for signs of external contamination with blood. Decontaminate the blood culture bottles, if necessary, per the laboratory’s practice.
Rationale: Decontamination prevents cross-contamination and reduces the risk of exposure to blood-borne pathogens.
Assist the patient to assume a comfortable reclining position for several minutes.
In the presence of the patient, label the specimen per the organization’s practice.¹³
Place the labeled specimen in a biohazard bag and transport it to the laboratory immediately per the organization’s practice.
Assess the patient’s tolerance of the venipuncture. Look for any signs of anxiety or fear that the patient experienced during the venipuncture.
Rationale: A patient may require more venipunctures in the future; therefore, addressing concerns and letting the patient express emotions may reduce any aversion to future venipunctures. Documenting the patient’s response allows for improved care planning for future venipunctures.
Reassess the venipuncture site to determine whether bleeding has stopped or a hematoma has formed.
Assess the patient for infection or phlebitis using standardized scales. Report pain, burning, stinging, erythema, warmth, or subcutaneous swelling to the practitioner.^9,10,11
Assess pain, treat if necessary, and reassess.
Report adverse events in an organization-approved occurrence-reporting system.¹⁸
Discard or store supplies, remove PPE, and perform hand hygiene.
Document the procedure in the patient’s record.

Blood Culture Collection via a CVAD

Avoid using a CVAD to obtain blood specimens for culturing because these samples are more likely to produce false-positive results. Obtain a blood culture via a CVAD only if diagnosing a CLABSI or if adequate peripheral sites are not available.⁸

Perform hand hygiene and don gloves. Don additional PPE based on the patient’s need for isolation precautions or the risk of exposure to bodily fluids.
At the patient’s side, prepare or compare laboratory requisitions and computer-generated labels (if available). Compare the labels with the patient’s self-identification (per the organization’s practice) by having the patient confirm the spelling of the patient’s full name and date of birth (when possible).
Do not draw blood if there is a discrepancy between the laboratory requisitions or labels and the patient’s identity.
1. Blood culture sets are usually drawn in immediate succession.
2. Blood specimens should be obtained from different peripheral sites.¹⁵
Indicate the volume of blood needed for each test on the label on each bottle. The amount of blood needed for the most accurate analysis is 10 ml of blood for each bottle.¹⁷
Assess the patient’s external CVAD site for signs and symptoms of sepsis or infection, as well as leakage and dressing integrity. Report signs and symptoms of sepsis or infection to the practitioner immediately.
Select the appropriate CVAD lumen for blood sampling. The appropriate lumen is the largest one that is farthest from the heart and does not have instilled antibiotics.⁸
If the CVAD is multilumen, draw a separate blood specimen from each CVAD lumen and label appropriately.⁸
Clamp the CVAD lumen before detaching any IV tubing, syringes, or devices if the CVAD has a needleless connector cap with no internal mechanism.
Rationale: Clamping the lumen prevents blood reflux out of the CVAD lumen.
If the IV tubing must be detached from the CVAD, place a sterile cap on the IV tubing.
Rationale: Placing a sterile cap on the detached tubing maintains asepsis of the IV system.
Disinfect the connection surface and sides of the needleless connector using vigorous mechanical scrubbing for a minimum of 5 to 15 seconds, according to the organization’s practice, using a flat swab pad containing 70% isopropyl alcohol or alcohol-based chlorhexidine suitable for use with medical devices.⁶ Allow the solution to dry.⁶
If IV solutions or medications are infusing through the CVAD, determine whether stopping the infusion affects the patient’s hemodynamic stability. If appropriate, stop all infusions or medications for the blood specimen collection.
Rationale: Research has not established a length of time for stopping the infusion of IV solutions or medications before obtaining blood from CVADs but is associated with the internal volume of the specific CVAD device.⁸
Flush the CVAD lumen with 10 to 20 ml of a commercially available, prefilled syringe of 0.9% preservative-free sodium chloride solution.^7,8
Rationale: Commercially available, prefilled syringes decrease the risk of CLABSI, save time for syringe preparation, and aid in optimal flushing technique.⁷
Use an appropriate-size syringe to gently aspirate 10 ml of blood per bottle from the CVAD lumen for accurate blood culture results per the manufacturer’s instructions and the organization’s practice.⁸
Carefully evaluate the patient for the potential for venous collapse when using a syringe barrel that is 10 ml or larger.¹⁸ Consider that young children, older adults, and those who have received treatments that are damaging to the veins may not be able to withstand high pressure or may require a smaller syringe barrel.

Do not discard the initial sample from a CVAD because discarding does not reduce contamination rates or increase the sensitivity of blood cultures, and it can contribute to anemia.^8,18
Fill the blood culture collection bottles.
1. Connect the blood sampling syringe to a sterile safety transfer device and fill the blood culture collection bottles.
2. Connect the CVAD lumen directly to the culture collection bottle and fill the blood culture collection bottles.
  If using a blood culture bottle designed for direct filling from the CVAD, ensure that the bottle remains upright and follow the manufacturer’s instructions for use (IFU).⁸
  
  Rationale: Following the manufacturer’s IFU prevents reflux of the broth medium into the patient’s CVAD and vein.⁸
Keep the bottle and syringe upright and inoculate the culture bottle, ensuring that no air is transferred from the syringe into the bottle. Inject 10 ml of blood into each bottle.⁸
Rationale: Blood obtained from a single site should be divided evenly between the aerobic and anaerobic bottles. Transferring air trapped in the syringe alters the bottle’s anaerobic environment. If the bottle and syringe are held upright, air near the syringe plunger should not enter the first (anaerobic) culture bottle. Air is acceptable in the second (aerobic) bottle.

After skin antisepsis, the volume of cultured blood is the next most important variable affecting the sensitivity of detection of bacteria and fungi in the blood.
Repeat the procedure for other CVAD lumens (as applicable). Ensure that the culture bottles are correctly labeled to indicate which lumen was used to collect each set of blood cultures.
Follow the manufacturer’s IFU and the organization’s practice for the appropriate-size syringe for aspiration.
Repeat the blood specimen collection sequence for additional sets of blood cultures. Blood culture sets are usually drawn in immediate succession.
Rationale: Unless ordered by the practitioner or per the laboratory’s practice, blood cultures should be obtained from at least two separate blood draws on the same day or consecutive days and with two separate site preparations.
Gently mix the culture broth and blood in the bottles.
Rationale: Mixing gently blends the medium and the blood.
Examine the culture bottles for signs of external contamination with blood. Decontaminate the bottles, if necessary, per the laboratory’s practice.
Rationale: Decontamination prevents cross-contamination and reduces the risk of exposure to blood-borne pathogens.
Flush all the CVAD lumens with 10 to 20 ml of commercially available, prefilled syringes of 0.9% preservative-free sodium chloride solution after obtaining blood specimens.^7,8
Rationale: Flushing CVAD lumens after obtaining a blood specimen decreases the possibility of changing intraluminal pressure causing blood reflux into the other lumens.⁷
Place a new needleless connector cap, using aseptic technique. Ensure that no air enters the CVAD system.
Consider the use of disinfection caps to reduce microbial contamination and rate of CLABSI.
Assist the patient to a comfortable reclining position for several minutes.
In the presence of the patient, label the specimen per the organization’s practice.¹³
Place the labeled specimen in a biohazard bag and transport it to the laboratory immediately per the organization’s practice.
Assess the patient’s tolerance of the venipuncture. Look for any signs of anxiety or fear that the patient experienced during the venipuncture.
Rationale: A patient may require more venipunctures in the future; therefore, addressing concerns and letting the patient express emotions may reduce any aversion to future venipunctures. Documenting the patient’s response allows for improved care planning for future venipunctures.
Reassess the venipuncture site to determine whether bleeding has stopped or a hematoma has formed.
Assess the patient for infection or phlebitis using standardized scales. Report pain, burning, stinging, erythema, warmth, or subcutaneous swelling to the practitioner.^9,10,11
Assess pain, treat if necessary, and reassess.
Report adverse events in an organization-approved occurrence-reporting system.¹⁸
Discard or store supplies, remove PPE, and perform hand hygiene.
Document the procedure in the patient’s record.

EXPECTED OUTCOMES

Venipuncture is successful without nerve or adjacent tissue injury.
Aseptic technique is maintained.
Venipuncture site shows no evidence of continued bleeding or hematoma after blood specimen collection.
Patient tolerates procedure with minimal anxiety, fear, or discomfort.
All required laboratory blood specimens are collected, and accurate results are obtained.

UNEXPECTED OUTCOMES

Hematoma forms at venipuncture site.
Infection or phlebitis develops at venipuncture site.
Nerve or adjacent tissue injury occurs.
Patient has vasovagal response, including dizziness, fainting, or loss of consciousness.
Hemostasis is not achieved.
Blood culture has a false-positive result.
Blood culture specimen is inadequate for testing and cannot be processed.
Aseptic technique is not maintained.
Needlestick injury occurs.

DOCUMENTATION

Date and time of venipuncture, number and location of attempts, and name and credentials of person performing procedure
Blood cultures obtained and disposition of specimens
Location and description of venipuncture site
Volume of blood drawn for a pediatric patient, a patient undergoing frequent blood sampling, or a patient with anemia
Inability to obtain blood cultures, if unsuccessful
Patient’s tolerance of venipuncture
Education
Patient’s progress toward goals
Unexpected outcomes and related interventions
Assessment of pain, treatment if necessary, and reassessment

OLDER ADULT CONSIDERATIONS

Older adults have fragile veins that are easily traumatized during venipuncture. Applying a warm compress may help with obtaining a blood sample. Using a small-gauge needle may also help.
The appropriate-size vacuum bottles or tubes and vacuum strength should be used. Large tubes with full vacuum may exert too much pressure on an older adult’s vein.
An older adult may not be able to withstand vacuum-system pressure or may require a smaller tube. Pressure from larger tubes may cause vein wall damage, leading to infiltration.

REFERENCES

Dean, A.J., Lee, D.C. (2019). Chapter 67: Bedside laboratory and microbiological procedures. In J.R. Roberts and others (Eds.), Roberts and Hedges’ clinical procedures in emergency medicine and acute care (7th ed., pp. 1442-1469). Philadelphia: Elsevier.
Doern, V.G. and others. (2019). A comprehensive update on the problem of blood culture contamination and a discussion of methods for addressing the problem. Clinical Microbiology Reviews, 33(1), e00009-e00019. doi:10.1128/CMR.00009-19 Retrieved May 12, 2023, from https://magnolia-medical.com/wp-content/uploads/2020/10/Doern_Blood-Culture-Contamination-Review-Call-to-Action_CMR_January-2020-1.pdf (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 26: Vascular access device planning. Journal of Infusion Nursing, 44(Suppl. 1), S74-S81. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 27: Site selection. Journal of Infusion Nursing, 44(Suppl. 1), S81-S86. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 33: Vascular access site preparation and skin antisepsis. Journal of Infusion Nursing, 44(Suppl. 1), S96. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 36: Needleless connectors. Journal of Infusion Nursing, 44(Suppl. 1), S104-S107. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 41: Flushing and locking. Journal of Infusion Nursing, 44(Suppl. 1), S113-S118. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 44: Blood sampling. Journal of Infusion Nursing, 44(Suppl. 1), S125-S133. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 46: Phlebitis. Journal of Infusion Nursing, 44(Suppl. 1), S138-S141. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 47: Infiltration and extravasation. Journal of Infusion Nursing, 44(Suppl. 1), S142-S147. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 50: Infection. Journal of Infusion Nursing, 44(Suppl. 1), S153-S157. (Level I)
Infusion Nurses Society (INS). (2021). Infusion therapy standards of practice. Standard 55: Catheter-associated skin injury. Journal of Infusion Nursing, 44(Suppl. 1), S168-S170. (Level I)
Joint Commission, The. (2023). National Patient Safety Goals for the home care program. Retrieved May 12, 2023, from https://www.jointcommission.org/-/media/tjc/documents/standards/national-patient-safety-goals/2023/npsg_chapter_ome_jan2023.pdf (Level VII)
Occupational Safety and Health Administration (OSHA). (n.d.). Patient care unit: Needlestick/sharps injuries. Retrieved May 12, 2023, from https://www.osha.gov/etools/hospitals/patient-care-unit/needlestick-sharps-injuries (Level VII)
Pagana, K.D., Pagana, T.J., Pagana, T.N. (2021). Chapter B: Blood culture and sensitivity. In Mosby’s diagnostic and laboratory test reference (16th ed., pp. 122-176). St. Louis: Elsevier.
Warekois, R.S., Robinson, R., Primrose, P.B. (2020). Chapter 11: Preanalytic variables and venipuncture complications. In Phlebotomy: Worktext and procedures manual (5th ed., pp. 176-193). St. Louis: Elsevier.
Warekois, R.S., Robinson, R., Primrose, P.B. (2020). Chapter 14: Special collections and procedures. In Phlebotomy: Worktext and procedures manual (5th ed., pp. 218-233). St. Louis: Elsevier.
World Health Organization (WHO). (2010). WHO guidelines on drawing blood: Best practices in phlebotomy. Retrieved May 12, 2023, from https://apps.who.int/iris/bitstream/handle/10665/44294/9789241599221_eng.pdf?sequence=1&isAllowed=y (classic reference)* (Level VII)

*In these skills, a “classic” reference is a widely cited, standard work of established excellence that significantly affects current practice and may also represent the foundational research for practice.

Elsevier Skills Levels of Evidence

Level I - Systematic review of all relevant randomized controlled trials
Level II - At least one well-designed randomized controlled trial
Level III - Well-designed controlled trials without randomization
Level IV - Well-designed case-controlled or cohort studies
Level V - Descriptive or qualitative studies
Level VI - Single descriptive or qualitative study
Level VII - Authority opinion or expert committee reports

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