by Dennis Ernst • June 12, 2018 Throughout history, tourniquets have been used to restrict blood flow. It's one of the simplest and most effective medical devices ever created, yet has changed very little over time. While the material tourniquets are constructed from have evolved from vines and rope to a non-latex elastomers of many colors, little else has changed. Because they constrict circulation, tourniquets save lives by stopping hemorrhages, and make venipunctures and IV therapy possible. Tourniquets also have a dark side. When forgotten after a venipuncture, a tourniquet that continues to restrict blood flow often leads to deep vein thrombosis (DVT), a dangerous and life-threatening complication that can cause permanent injury, even death. National statistics are hard to come by, but healthcare facilities in the state of Pennsylvania alone reported 125 incidents of forgotten tourniquets in one year. In one third of the incidents, tourniquets were left on up to 18 hours. Extrapolating that statistic to the entire US, healthcare professionals forget tourniquets on nearly 3,000 patients every year. Many lead to complications and litigation. Complications include pain, swelling, skin sores, varicose veins, post-thrombotic syndrome, amputation, pulmonary embolism and death. Performing venipunctures without tourniquets is not an option. Constriction of the circulation causes veins to distend as they fill up with blood that can no longer circulate. Distended veins are easier to palpate and access. The standards also require a thorough survey of available veins so that those most likely to be near nerves can be avoided. Without tourniquet constriction, a thorough survey cannot be conducted. [Editor's Note: many are under the false impression that lactates must be drawn without a tourniquet. However, no study has shown lactates to be affected by tourniquets applied for one minute, as is the case for routine phlebotomies. Only when left on for five minutes or longer, which is against the standards, are lactates affected.] To prevent forgotten tourniquets and the complications that can ensue, facilities should adopt aggressive strategies. Some suggestions include:
Deep vein thrombosis is a life-threatening risk everyone who draws blood samples must take seriously. Some of the above measures may seem drastic. Given the potential for patient death, drastic is often required. Read a related story. This chapter covers all the steps recommended for safe phlebotomy and reiterates the accepted principles for blood drawing and blood collection (31). The chapter includes background information (Section 2.1), practical guidance (Section 2.2) and illustrations (Section 2.3) relevant to best practices in phlebotomy. The information given in this section underpins that given in the remainder of Part II for specific situations. Chapter 4 also provides information relevant to the procedure for drawing blood given below in Section 2.2, but focuses on blood collection from donors. Institutions can use these guidelines to establish standard operating procedures. Such procedures should clearly state the risks to patients and health workers, as well as the means to reduce those risks – discussed below in Sections 2.1.4 and 2.2. Best practices in phlebotomy involve the following factors:
This is the most important part of carrying out any procedure, and is usually done at the start of a phlebotomy session. The phlebotomist should work in a quiet, clean, well-lit area, whether working with outpatients or inpatients. Quality assurance is an essential part of best practice in infection prevention and control (1). In phlebotomy, it helps to minimize the chance of a mishap. Table 2.1 lists the main components of quality assurance, and explains why they are important. Several factors can improve safety standards and quality of care for both patients and health workers, and laboratory tests. These factors, discussed below, include: Procurement of supplies is the direct responsibility of the administrative (management) structures responsible for setting up phlebotomy services. Management should:
Several safety-engineered devices are available on the market; such devices reduce exposure to blood and injuries. However, the use of such devices should be accompanied by other infection prevention and control practices, and training in their use. Not all safety devices are applicable to phlebotomy. Before selecting a safety-engineered device, users should thoroughly investigate available devices to determine their appropriate use, compatibility with existing phlebotomy practices, and efficacy in protecting staff and patients (12, 33). Annex B provides further information on infection prevention and control, safety equipment and best practice; Annex C provides a comprehensive guide to devices available for drawing blood, including safety-engineered equipment. For settings with low resources, cost is a driving factor in procurement of safety-engineered devices. Where safety-engineered devices are not available, skilled use of a needle and syringe is acceptable. Accidental exposure and specific information about an incident should be recorded in a register. Support services should be promoted for those who undergo accidental exposure. PEP can help to avert HIV and hepatitis B infections (13, 27). Hepatitis B immunization should be provided to all health workers (including cleaners and waste handlers), either upon entry into health-care services or as part of PEP (34). Annex D has details of PEP for hepatitis B and HIV. Tourniquets are a potential source of methicillin-resistant Staphylococcus aureus (MRSA), with up to 25% of tourniquets contaminated through lack of hand hygiene on the part of the phlebotomist or reuse of contaminated tourniquets (35). In addition, reusable finger-prick devices and related point-of-care testing devices (e.g. glucometers) contaminated with blood have been implicated in outbreaks of hepatitis B (4, 5, 36). To avoid contamination, any common-use items, such as glucometers, should be visibly clean before use on a patient, and single-use items should not be reused. All staff should be trained in phlebotomy, to prevent unnecessary risk of exposure to blood and to reduce adverse events for patients.
One of the essential markers of quality of care in phlebotomy is the involvement and cooperation of the patient; this is mutually beneficial to both the health worker and the patient. Clear information – either written or verbal – should be available to each patient who undergoes phlebotomy. Annex F provides sample text for explaining the blood-sampling procedure to a patient. Factors that influence the outcome of laboratory results during collection and transportation include:
2.2.1. Provision of an appropriate location
Ensure that the indications for blood sampling are clearly defined, either in a written protocol or in documented instructions (e.g. in a laboratory form). At all times, follow the strategies for infection prevention and control listed in Table 2.2. Collect all the equipment needed for the procedure and place it within safe and easy reach on a tray or trolley, ensuring that all the items are clearly visible. The equipment required includes:
Ensure that the rack containing the sample tubes is close to you, the health worker, but away from the patient, to avoid it being accidentally tipped over. Where the patient is adult and conscious, follow the steps outlined below.
For paediatric or neonatal patients, see Chapter 6. General
In hospitalized patients, do not take blood from an existing peripheral venous access site because this may give false results. Haemolysis, contamination and presence of intravenous fluid and medication can all alter the results (39). Nursing staff and physicians may access central venous lines for specimens following protocols. However, specimens from central lines carry a risk of contamination or erroneous laboratory test results. It is acceptable, but not ideal, to draw blood specimens when first introducing an in-dwelling venous device, before connecting the cannula to the intravenous fluids. Step 4. Perform hand hygiene and put on gloves
Step 5. Disinfect the entry site
Perform venepuncture as follows.
Step 7. Fill the laboratory sample tubes
Draw blood collection tubes in the correct order, to avoid cross-contamination of additives between tubes. As colour coding and tube additives may vary, verify recommendations with local laboratories. For illustration purposes, Table 2.3 shows the revised, simplified recommended order of draw for vacuum tubes or syringe and needle, based on United States National Committee Clinical Laboratory Standards consensus in 2003 (43). Step 9. Clean contaminated surfaces and complete patient procedure
Step 10. Prepare samples for transportation
If blood spillage has occurred (e.g. because of a laboratory sample breaking in the phlebotomy area or during transportation, or excessive bleeding during the procedure), clean it up. An example of a safe procedure is given below.
If a person was exposed to blood through nonintact skin, mucous membranes or a puncture wound, complete an incident report, as described in WHO best practices for injections and related procedures toolkit. For transportation of blood samples outside a hospital, equip the transportation vehicle with a blood spillage kit. Annex H has further information on dealing with a blood spillage. |