Safety and phlebotomy: Considerations for a common invasive procedure

Phlebotomy — collecting a blood specimen directly from the circulatory system via puncture for analysis and diagnosis — is one of the most common invasive procedures in healthcare. Approximately 450 million blood draws occur each year in U.S. hospitals,¹ which may lead some to take phlebotomy for granted. However, the humble blood draw is an essential step in the journey to diagnosing, monitoring, and treating countless health conditions. It also comes with inherent risks to patients and health workers alike.

Safety in phlebotomy can be divided into two major categories: patient safety and healthcare worker safety.

Patient safety includes the risk of injury or harm as a result of the blood collection process.
Healthcare worker safety includes protection from exposure to bloodborne pathogens and needlestick injuries.

For patients, the potential physical effects of unsafe phlebotomy range from pain and bruising to nerve damage or hematoma.² For healthcare workers, the primary physical concerns are sharps injuries and accidental exposure to infectious agents. Standards of care and best practices, along with advances in sharps injury prevention measures, all contribute to establishing a physically safe blood draw.

Adherence to clinical laboratory standards for phlebotomy also helps ensure specimen quality and subsequent test result integrity. The benefits of obtaining a high-quality specimen are two-fold – it not only contributes to accurate diagnosis and/or therapy management for the patient, but also reduces the need for additional blood draws that would be required in the case of an unacceptable specimen.

Preparing for safe blood specimen collection

For any healthcare worker performing phlebotomy, safety begins even before a patient encounter. From practicing in a safe environment to assembling the proper materials ahead of time, for example in a phlebotomy tray or cart, preparation sets the stage for safe blood collection.

The World Health Organization (WHO) has established five key points in phlebotomy preparation that can directly contribute to patient and health worker safety as well as sample quality:²

Availability of appropriate supplies and protective equipment, including a sufficient supply of blood collection tubes and safety-engineered equipment
Availability of post-exposure prophylaxis
Avoidance of contaminated phlebotomy equipment
Adequate training in phlebotomy
Patient cooperation, aided by clear communication throughout the procedure

Adequate training cannot be overstressed, especially since professionals from many different healthcare disciplines with varying degrees of experience or specialization in phlebotomy may be responsible for collecting blood samples. Standards for safe practice aim to equip and protect them all but are only effective with proper education.

Safety from the first “Hello”

The first introductions with a patient can set the tone for safe sample collection. Guidelines from both CLSI (Clinical Laboratory Standards Institute) and WHO emphasize addressing patients with empathy and respect from the first “Hello.”

Always remember: Patients are human beings, and each one is unique. Phlebotomy often happens in high-pressure environments — it can be challenging to slow down and connect with each patient. But a patient-centered approach can make all the difference.

Phlebotomists draw samples from a wide range of patient populations. Even within a single acute care facility, the same phlebotomist may be responsible for collecting blood samples from multiple units in a day — from the ICU to pediatrics, the emergency department to medical/surgical and anywhere in between. With such diverse patients, being able to correctly assess each one’s unique condition and select the appropriate approach and products for their specimen collection is a crucial skill to improving safety and sample quality.

A few simple steps in patient assessment include:

Ask whether the patient has any allergies, phobias related to blood draws, or other conditions that may influence specimen collection.
Note if the patient appears anxious or afraid; if so, take extra steps to make them comfortable.
Be aware of any physical limitations that may prohibit comfortable arm extension, such as injury or stroke.
For pediatric patients, ask whether a parent would like to assist by holding or comforting the child.
In inpatient scenarios, take note of any signage, bracelets, or other indicators signaling patient-specific precautions.³

Identifying the patient

While it may seem like an obvious precaution, patient identification should never be overlooked. A recent study found that 53% of wrong blood in tube (WBIT) errors involved a combination of protocol violations and slips/lapses.⁴ Whether the intended patient is drawn, and an incorrect sample label is applied or vice versa, the potential risks of a WBIT error include misdiagnosis and inappropriate therapies, which may lead to serious injury and even death.

CLSI advises taking extra precautions in high-risk situations, such as when drawing from siblings or twins; patients with common names, look-alike or sound-alike names; and multiple patients within the same room. The same study that linked WBIT errors to protocol lapses also found that 61% of WBIT errors occurred when another patient’s sample labels or tubes were available during phlebotomy.⁴ It is possible to misidentify a sample even when using electronic positive patient identification, so always double-check that you have both the intended patient and correct tube labels.

Collecting the sample

Once satisfied that the patient, test requests, and sample labels are verified, sample collection may begin. When performing a venous sample collection, the physical risks largely center on injury or accidental exposure. The risks to clinical accuracy include selecting inappropriate products for the required draw or improper collection site preparation and tube handling.

Having the proper tools within reach helps ensure both physical safety and clinical integrity during sample collection. For venipuncture, this includes a needle of appropriate gauge for the patient’s vein conditions. Too large of a needle may damage the vein while too small may contribute to higher rates of hemolysis.

CLSI also strongly encourages the use of safety-engineered blood collection devices, such as safety winged collection sets (“butterflies”). Safety devices, when used according to manufacturer’s instructions and activated immediately after specimen collection, help reduce the risk of needlestick injuries.

Collection site selection and preparation also factor into a safe draw and quality sample. CLSI recommends drawing venous blood samples from the antecubital fossa – the interior of the elbow bend. This area features several large veins that are relatively easy to access. The veins in the center of this area (median cubital veins) also lay over a fibrous membrane that offers additional protection to underlying nerves and arteries.³

The use of a tourniquet may aid vein palpation and specimen collection, but also poses risks to sample integrity when used inappropriately. Pay attention to the amount of pressure – it should feel comfortable to the patient while exerting enough pressure to make the veins more prominent – and the amount of time a tourniquet is applied. More than one minute may cause hemoconcentration, which affects several analytes. Note that vein selection, supply assembly, glove donning, site cleansing, needle insertion and establishment of blood flow must all occur during this minute, so plan accordingly and have supplies ready at hand.

Once a vein is selected, supplies are assembled, and gloves are donned, the collection site must be cleansed with a 70% isopropyl alcohol solution to minimize the risk of specimen contamination or patient infection. Allowing the alcohol solution to air dry will ensure decontamination and reduce the likelihood of a burning sensation during venipuncture. The site must be re-cleansed if palpated again before venipuncture.

Tips for safe and successful venipuncture include the following:

· Anchor the vein from below, never from above, which increases needlestick risks.

· Be prepared for sudden, unexpected patient movements.

· Insert the needle at an angle of 30° or less.

· Release the tourniquet as soon as blood flow is established (unless doing so may cause vein collapse).

Once the needle is successfully inserted into the vein, sample collection may begin. When using evacuated tubes, blood should flow freely into the tube to the required draw volume (that is, until the vacuum is exhausted). Once filled, the tube may be removed from the needle/holder and mixed by gentle inversion according to manufacturer’s instructions for use before inserting additional tubes as required.

Be careful to observe the recommended order of draw as outlined by CLSI GP41 or according to facility protocol. Adhering to the order of draw makes a considerable contribution to sample quality by ensuring that the additives of the previous tube do not carry over into subsequent tubes, causing interference and ultimately erroneous results.

Immediately upon completion of sample collection, remove the needle and activate the safety mechanism according to the manufacturer’s instructions.

Post-collection sample handling

After administering post-venipuncture care, properly disposing of sharps, and ensuring the patient is comfortable, samples must be labeled while still in the patient’s presence. Once again, verify the tube labels match the patient’s identification and test request.

Observe any special requirements for sample transportation, such as the need for refrigeration, protection from light, or other considerations to preserve specimen integrity.

Conclusion

To achieve the best possible results in the safest possible manner, it is essential to consider the entire phlebotomy process holistically. Every step, from evaluating the patient to venipuncture and specimen tube handling, can influence sample quality and impact the patient’s health.

References

Psaila J, Parsons TF, Hahn SA, Fichera L. Prospective Study Evaluating Whether Standard Peripheral Intravenous Catheters Can Be Used for Blood Collection Throughout Hospital Stay. J Infus Nurs. 2023;46(1):43-47. doi:10.1097/NAN.0000000000000493.
Best Practices in Phlebotomy. World Health Organization; 2010.
Collection of Diagnostic Venous Blood Specimens.; 2017.
Dunbar NM, Kaufman RM; WBIT Study Investigators, The Biomedical Excellence for Safer Transfusion (BEST) Collaborative. Factors associated with wrong blood in tube errors: An international case series - The BEST collaborative study. Transfusion. 2022;62(1):44-50. doi:10.1111/trf.16716.