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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#ref3">3
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.
A blood culture specimen set requires that 20 to 30 ml1 of blood be obtained at one time from one location. 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.18 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 venous access device (CVAD) may be ordered. A CVAD specimen should be used only when a central line–associated bloodstream infection (CLABSI) is suspected.14 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.11,14 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.18 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.18
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’s 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.8 Staphylococcus aureus contamination from reused tourniquets is a common finding.21
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.
Rationale: Drawing blood specimens from such sites can result in false test results o may injure the patient.
Rationale: Three blood culture samples should be drawn at least 1 hour apart beginning at the earliest signs of sepsis.18
Rationale: Resin can be added to the culture medium to negate the antibiotic effect.
Rationale: A low, supported position and an empty mouth2 reduce the risk of injury to the patient if he or she experiences lightheadedness, faints from vagal stimulation, or experiences a seizure.
Be prepared to manage a venipuncture-associated vasovagal reactions for an at-risk patient.
Do not draw blood if there is a discrepancy between the laboratory requisitions or labels and the patient’s identity.2
Rationale: Correct patient positioning helps stabilize the extremity.
Consult with the practitioner about stopping the IV infusion 30 seconds to 2 minutes before obtaining the blood specimen (as applicable).4,11
Rationale: A tourniquet blocks venous return to the heart from the extremity, causing the veins to dilate for easier access.
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.
Do not keep the tourniquet on the patient longer than 1 minute11 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.11
Rationale: A patent, healthy vein is elastic and rebounds on palpation. A thrombosed vein is rigid, rolls easily, and is difficult to puncture.21
Do not use a vein that feels rigid or cordlike or one that rolls when palpated.
Rationale: Warming enhances blood flow, making veins more prominent.
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.5
Rationale: Needles that are 22 G or smaller minimizes insertion-related trauma to the vein.6
Rationale: Safety devices can decrease the risk of needlestick injury by 75%.21
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.21 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.21
Keep the needle hub and the connection sites sterile.
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.
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.
Do not touch the site after preparation unless sterile gloves are worn.2
If contamination occurs, discard the needle and the collection barrel or syringe in a sharps container and prepare a new venipuncture set.
Rationale: Gently stretching the patient’s skin helps stabilize the vein and prevent rolling during needle insertion.
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.
Rationale: Inserting the needle slowly prevents puncture through the opposite side of the vein.
Rationale: The aerobic bottle should be inoculated first because there is about 0.5 ml of air in the line of the butterfly-winged collection set and sometimes it is difficult to obtain 8 to 10 ml of blood per culture bottle (15 to 20 ml per culture set).19,20 The aerobic bottle is the more critical bottle to inoculate for laboratory test results.19,20 The small lines on the edge of the label indicate approximately 5 ml, and there is a fill line denoted on the bottle label.19,20
Do not to underfill or overfill the culture bottles because this can adversely affect the laboratory test results.
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.
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.4
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.
Rationale: Releasing the tourniquet before filling the last blood specimen tube reduces bleeding at the site when the needle is withdrawn.
Rationale: Applying pressure over the needle can cause discomfort and injury to the patient. Carefully removing the needle minimizes discomfort and vein trauma.
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.
Do not use a cotton ball or a rayon ball when applying pressure because of the potential for dislodging the platelet plug at the venipuncture site.2
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.
Carefully evaluate the patient for the potential for venous collapse when using a syringe barrel that is 10 ml or larger.21 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.
Rationale: Releasing the tourniquet before drawing the last of the blood reduces bleeding at the site when the needle is withdrawn.
Rationale: Transferring from 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 anaerobic culture 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.
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.17
Do not recap needles or attempt to remove the needle from the collection barrel.17
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.11
Rationale: Mixing gently blends the medium and the blood.
Rationale: Decontamination prevents cross-contamination and reduces the risk of exposure to blood-borne pathogens.
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.
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.11
Rationale: Clamping the lumen prevents blood reflux out of the CVAD lumen.
Rationale: Placing a sterile cap on the detached tubing maintains asepsis of the IV system.
The drying time for 70% isopropyl alcohol is 5 seconds; for alcohol-based chlorhexidine, it is 20 seconds.9
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.11
Rationale: Commercially available, prefilled syringes decrease the risk of CLABSI, saves time for syringe preparation, and aids in optimal flushing technique.10
Carefully evaluate the patient for the potential for venous collapse when using a syringe barrel that is 10 ml or larger.21 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.11,21
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.11
Rationale: Following the manufacturer’s instructions for use prevents reflux of the broth medium into the patient’s CVAD and vein.11
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.
Follow the manufacturer’s instructions for use and the organization’s practice for the appropriate-size syringe for aspiration.
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.
Rationale: Flushing CVAD lumens after obtaining a blood specimen decreases the possibility of changing intraluminal pressure causing blood reflux into the other lumens.10
Consider the use of disinfection caps to reduce microbial contamination and rate of CLABSI.
O’Grady, N.P. and others. (2011, updated 2017). Guidelines for the prevention of intravascular catheter-related infections, 2011. Centers for Disease Control and Prevention. Retrieved June 28, 2021, from https://www.cdc.gov/infectioncontrol/pdf/guidelines/bsi-guidelines-H.pdf
*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.
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