Which of the following needles should a phlebotomist use for collecting units of blood for donation?

Work Evaluation and job Simulation Case Example

In a case in which a phlebotomist sustained a cerebrovascular accident, her employer was not willing to allow her to return to work because she did not have any sensation in her dominant, affected hand distal to the wrist. The patient-employee insisted that she would be able to perform her job duties without the presence of sensation because she always has her eyes on the hand during the process of drawing blood (i.e., inserting the needle into the vein) and that she needed the sensation in her nondominant hand to palpate the vessels. With the patient’s permission, the employer was contacted and agreed to allow the phlebotomist’s job to be assessed to see if this was possible. During the job task assessment, two phlebotomists and a supervisor were interviewed and observed performing their work tasks. There was consensus that a phlebotomist does not use the sensation in the dominant hand and always visualizes the blood-drawing equipment during blood collection. The employer agreed that if the patient-employee could successfully demonstrate this during job simulation and then in live practice trials, she could return to her job. The phlebotomy department provided the therapist with needed tools (i.e., vacutainer and vials), and part of the patient’s outpatient therapy regimen included working with these tools in a job simulation using fruit and then a Simulaid (a mannequin arm specially made for this purpose) and then in actual trials of drawing blood from her therapists. The patient-employee was able to safely demonstrate competence in her work tasks at all levels and was allowed to return to her work.

3.05.5.5 Gloves

Even though phlebotomists wash their hands before and after blood collection, gloves should still be worn, even when palplating for veins. Gloves offer protection from the transmission of infectious diseases between the phlebotomist and patient. If the skin integrity is damaged, a bandage worn under gloves offers increased exposure protection. Gloves are manufactured with different types of materials such as latex and nitrile. With the increasing prevalence of latex allergies, many institutions have switched to using nitrile-based gloves. If a phlebotomist cannot avoid wearing latex gloves, the option of wearing glove liners underneath is also possible. Gloves should never be reused nor disinfected with intentions for reuse.5

Preliminary Steps.

In many institutions, at this point in the process, the patient should be asked about latex allergies. If latex allergy is present and if latex gloves or a latex tourniquet may be used, the phlebotomist should secure an alternative tourniquet and put on gloves that are latex free. Finally, for some specialized tests such as testing for genetic diseases, the performing laboratory may request a signed consent form from the patient or the use of a special requisition; these should be completed at the time of collection if not provided by the requesting physician.

Before collection of a specimen, the phlebotomist should dress in personal protective equipment (PPE), such as an impervious gown and gloves applied immediately before approaching the patient, and adhere to standard precautions against potentially infectious material; the goal is to limit the spread of infectious disease from one patient to another and to promote the safety of the phlebotomist. Because small children are often frightened of anyone in a white coat or gown, pediatric phlebotomists often dress in bright, cheerful colors, including colored PPE rather than standard white. Pediatric drawing stations are also often brightly colored with lots of distracters for the patient. If the phlebotomist must collect a specimen from a patient in isolation in a hospital, the phlebotomist must put on a clean gown and gloves and a face mask and goggles before entering the patient's room. The face mask limits the spread of potentially infectious droplets, and the goggles limit the possible entry of infectious material into the eye. The extent of the precautions required varies with the nature of the patient's illness and the institution's policies and bloodborne pathogen plan, to which a phlebotomist must adhere. For example, if airborne precautions are indicated, the phlebotomist must wear an N95 tuberculosis respirator in the United States.

If appropriate, the phlebotomist should verify that the patient has fasted, identify what medications are being taken or have been discontinued as required, and determine any other relevant information required.Chapter 5 describes in more detail the effects of diet and fluid intake and the recommended steps for patient preparation, including fasting, before phlebotomy. The patient should be comfortable, seated or supine (if sitting is not feasible), and should have been in this position for as long as possible before the specimen is drawn. The correct interpretation of certain tests (eg, aldosterone, renin, plasma metanephrines) requires that the patient is in a supine position for at least 30 minutes before venipuncture. (For details on the effects of position, refer toChapters 5 and63.) For an outpatient, it is generally recommended that patients be seated before completion of the identification process to maximize their relaxation. At no time should venipuncture be performed on a standing patient.

Infants and young children may need to be held in order to restrain them and prevent movement. Young children may be held sitting upright in a parent's lap with the parent helping to support and hold the patient and arm still2 (Fig. 4.1). Infants' blood is often drawn with the infant in a supine position, and the infant may be swaddled in a blanket, or a papoose board may be used to restrain movement. Occasionally, the parents will be more anxious than the child, and the phlebotomist will need to make the decision to request help from a colleague phlebotomist to properly and safely perform the collection.3,4

SPECIMEN COLLECTION

The phlebotomist assigned to collect blood, plasma, or serum for analysis of toxins must be especially careful to avoid contamination of the draw site. Special metal-free collection equipment and vials must be used when collecting blood for analysis for screening for environmental metal toxins. Contamination of the collection site can be avoided with careful cleaning with an alcohol swab. Iodine-containing disinfectants are to be avoided. Special metal-free collection tubes must be used for specimen transport. Any commercially available stainless steel needle or butterfly device is acceptable.

Follow the instructions of your laboratory to determine what specimen type to use. In general, ethylenediaminetetraacetic acid (EDTA) is the preferred anticoagulant, primarily because other agents are more likely to give microclotting over time, which can clog instrumentation and make processing difficult.

Urine must be collected into a container that does not use a metal cap for closure and does not have any glued inserts into the cap, since they contain sufficient metals to give falsely elevated results. Do not collect urine in the environment in which exposure is suspected. Never use a colored container for collection because of metal-containing dyes.

Most organic or protein-based neurotoxins are present in low levels in biological fluids, often have a short half-life, and are only marginally stable at ambient temperatures. It is highly recommended to keep a chart handy that outlines the specimen handling requirements for your laboratory so that time is not wasted in specimen collection or the sample is not compromised by delays after it is removed from the body.

Technique for Obtaining Blood for Culture

False-positive blood cultures obtained in the ED can result in up to $8800 in additional costs, with an average increase in hospital length of stay of 1 day per patient.145 Studies have demonstrated sources of contamination at every stage of the process of performing and processing blood cultures. In addition to obvious sources of contamination from the patient's and phlebotomist's skin, antiseptic agents and gloves have been implicated.146,147 Some authorities have argued that the primary source of contamination is in the laboratory processing of specimens.148 The consensus is that the most common source of contamination is the process of phlebotomy and inoculation of blood culture bottles.145,149,150 Obviously, this is the single step over which emergency clinicians have control, either directly or via protocols of technique for blood culture phlebotomy. Contamination rates are typically between 1.5% and 3%,128,151,152 although many ED series show much higher rates.139,145,153 Conversely, settings in which there are rigorous protocols for obtaining blood cultures have contamination rates as low as 1%.150

A high degree of sensitivity is required for blood cultures. Many significant bacteremic illnesses have been documented with as little as 1 CFU/10 mL of blood.154,155 In a cadaver study, human skin has been shown to have a bacterial concentration of between 103 and 106 CFUs/mL on the forearm and groin, respectively.156 Designed to detect vanishingly low concentrations of bacteria, the test is clearly susceptible to false-positive results (impaired specificity) when blood must necessarily be obtained by passing a needle through the skin. Eighty percent of the skin flora is transient, superficial, and removable; 20% inhabit the sebaceous ducts and hair follicles and cannot be removed without destroying the skin.156,157 The former group consists of predominantly gram-positive and gram-negative aerobes and is the target of skin disinfectants.

The primary agents for skin disinfection are iodine compounds, alcohols, chlorhexidine, and hexachlorophene. Iodine solution remains a gold standard and kills bacteria, fungi, protozoa, and viruses but has been replaced in many institutions because of concern about skin burns and allergic reactions. Reports of the former were probably due to the use of 7% solution. The risk for a burn or an allergic reaction is thought to be negligible with the currently available 2% preparation.149 The most effective cleansing agent is tincture of iodine, which is a mixture of 2% iodine solution and 70% alcohol.158,159 Povidone-iodine 10% solution (Betadine, Purdue Pharma L.P., Stamford, CT) has a much lower free-iodine concentration than iodine solution and is therefore less potent. Iodine is superior to hexachlorophene and chlorhexidine in killing gram-negative bacteria. Iodine, like other antiseptic agents, is inhibited by the presence of organic matter and thus requires thorough skin cleansing before the application of any skin disinfectant.

Phlebotomy

Blood must be collected by a trained phlebotomist using aseptic methods, and a sterile, closed system. The blood unit should be collected from a suitable vein in a single venipuncture after the pressure device (blood pressure cuff or tourniquet) has been deflated and reinflated. WB is collected into a closed blood collection set consisting of a sterile collection bag containing anticoagulant (typically 70 mL of anticoagulant in a container approved to collect 500 ± 50 mL of WB), integrally attached tubing, and a large bore needle.

The total amount collected from the donor, including segments and specimen tubes, should not exceed 10.5 mL/kg of donor weight. During collection, blood should be thoroughly mixed with anticoagulant to prevent clotting, either manually or automatically.

Phlebotomy

Blood must be collected by a trained phlebotomist using aseptic methods, and a sterile, closed system. The blood unit should be collected from a suitable vein in a single venipuncture, within the antecubital fossa of the donor’s arm, after the pressure device (blood pressure cuff or tourniquet) has been deflated and re-inflated. Whole blood is collected into a closed blood collection set consisting of a sterile collection bag containing anticoagulant (typically 70 ml of anticoagulant is in a container to collect 500 ml ± 50 ml of whole blood), integrally attached tubing, and a large bore needle.

The total amount collected from the donor, including segments and specimen tubes, should not exceed 10.5 ml/kg of donor weight (whole blood collections). During collection, the blood should be mixed well with the anticoagulant in the bag to prevent clotting. Some blood centers use staff to agitate the bag from side to side to mix the fresh blood with anticoagulant; others utilize a specialized shaker device to mix the blood and anticoagulant mechanically.

Phlebotomy procedure

Staff undertaking this procedure should be adequately trained. The phlebotomist must check that the patient’s identity corresponds to the details on the request form and also ensure that the phlebotomy tray contains all the required specimen containers and other equipment necessary for the procedure.

A tourniquet should be applied just above the intended venepuncture site. Blood is best withdrawn from an antecubital vein or other visible veins of the forearm by means of either an evacuated tube or a syringe. It is recommended that the skin be cleaned with 70% alcohol (e.g., isopropanol) and allowed to dry spontaneously before being punctured. The tourniquet should be released as soon as the vein is punctured and blood begins to flow into the syringe or evacuated tube – delay in releasing the tourniquet leads to fluid shift and haemoconcentration as a result of venous blood stagnation.6 After the vein has been successfully punctured, the piston of the syringe should be withdrawn slowly with no attempt being made to withdraw blood faster than the vein is filling. Anticoagulated specimens must be mixed by inverting the container several times. The risk of unwanted haemolysis of the specimen can be minimised by using minimal tourniquet time, withdrawing blood carefully, using an appropriately sized needle, delivering the blood slowly into the receptacle and avoiding unnecessary agitation when mixing with the anticoagulant. Note that if blood is drawn too slowly or is inadequately mixed with the anticoagulant some coagulation may occur, rendering the sample unsuitable. After collection, containers must be firmly capped to minimise the risk of leakage.

If blood collection fails, it is important to remain calm, communicate with the patient and consider the possible causes. These include poor technique (e.g., passing the needle through the vein, or poor selection of veins), scarring of tissues and haematoma formation.

After obtaining the necessary specimens, remove the needle and press a sterile swab over the puncture site. Gentle pressure should be applied to the swab with the arm slightly elevated for a minute before checking that bleeding has completely ceased. Finally, the puncture site should be covered with a small adhesive dressing.

Obtaining blood from an indwelling line or catheter is an important potential source of error. It is common practice to flush indwelling lines with heparin, so they must be flushed free from heparin and the first 5 ml of blood must be discarded before any blood is collected for laboratory testing. If intravenous fluids are being transfused into an arm, blood should generally not be collected from that arm; however, if this is essential, the specimen should be obtained from below the intravenous infusion with the tourniquet being placed below the site of infusion.

1.6.2.3 Arterial blood collection

Collection of a blood specimen from an arterial site is more complicated and requires the phlebotomist have special training to properly perform the technique; otherwise a physician or a nurse should collect the blood specimen from this site. Arterial blood is used only for blood gas analysis including pO2, pCO2, pH, and sometimes lactate. The site of arterial blood collection, in their order of preference, is radial, brachial, and femoral arteries [16]. For neonates, umbilical artery catheter is the best site to collect the blood [16]; however, these sites need to be free of inflammation, infection, or edema.