Blood Management
May 2, 2021

Key Elements of A Successful Blood Draw

Drawing blood from indwelling catheters is more complicated in the NICU, but there are proven ways to ensure patient safety.
Drawing blood from indwelling catheters is more complicated in the NICU, but there are proven ways to ensure patient safety.

An experienced health care provider can make phlebotomy look simple, but there are actually a number of strategies and best practices being followed. From preparing their work area and introducing themselves to patients or guardians to ensuring that the drawing procedure is done properly and safely, nurses must keep many different factors in mind. By following known best practices, nurses can execute successful blood draws that yield a clean sample for testing and don’t cause harm to the patient.

However, the standards for a successful blood draw are much higher in the NICU because neonates are in such delicate health. A neonate’s total blood volume is only around 75mL per Kilo, so we have to be extremely careful when doing blood draws with these tiny patients. Hummingbird Med defines a “successful” UAC blood draw as one that yields a clean sample for testing without harming or hemodynamically disturbing the baby during the procedure. Unfortunately, current blood draw methods fall short on this last count, requiring excessive blood and fluid volume movement which can increase a neonate’s risk of developing serious conditions like intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL).

Here’s a quick reminder for NICU staff about the current methods for doing line draws from indwelling catheters in neonates.

How to Draw Blood: Key Considerations for NICU Staff

The three primary methods for drawing blood from indwelling catheters are: the open stopcock method, closed in-line blood draw systems, and fully disposable closed low volume blood draw method. Here’s how they work and how they differ.

Open Stopcock Method

Open, or “three-way,” stopcocks are tools that allow nurses to draw blood using multiple syringes for waste and blood collection, and a separate syringe for flushing. This method is often used by neonatal and pediatric units to take samples from umbilical and other central line catheters.

There are a number of drawbacks to using open stopcocks, however. They can require up to four separate line accesses per draw, lack standardized waste and flush volumes, and contain the risk of potential blood exposure for the caregiver as well as being an infection risk due to multiple accesses to an open port. Stopcocks can be difficult to clear after a draw and, when used in line, can quickly become hotspots for bacterial growth. Open stopcocks have a very high contamination rate due to multiple accesses, and they are a high CLABSI risk.

The use of open stopcocks remains common in part because of the cost and complexity as well as the blood volume movement and flush required to use many inline systems, despite the fact that a closed sampling method has been empirically proven to increase the risk of infection compared to closed port access procedures.

In-Line Blood Draw Systems

The advantage of the inline method is that it avoids many of the drawbacks of the open stopcock methods when it comes to infection risk. However, there are still some additional health considerations to be mindful of when performing inline sample collection. In-line systems have very high dead space volumes, requiring high volumes of blood clearance and flushing.  With these systems, residual blood often remains in the line and line components even after flushing. Repeated draws using the same system will increase the risk of the line components developing biofilm, which can lead to bacterial growth and infection.

While the inline system offers a better alternative to the open stopcock method, research continues to show that the amount of blood and fluid movement when using these systems causes a higher degree of hemodynamic change and are directly linked to a higher risk of developing IVH, PVL, and other serious health complications. Often, 4mL to 6mL of fluid movement is required for blood sampling using current closed-in-line systems.

Fully Closed, Disposable Low Volume Method: Hummi Micro Draw Blood Transfer Device

The Hummi Blood Transfer Device offers a better, safer way to draw blood from neonates. The Hummi Micro Draw only requires one access point through a closed port for each blood draw, reducing the risk of infection through the use of the smallest blunt cannula (1mm) of any blood draw system. The Hummi Micro Draw is placed directly into the catheter hub for drawing waste and sampling blood directly from the catheter. This allows for a reduced clearance blood volume of over 70% due to bypassing the dead space normally requiring clearance, while simultaneously reducing flush volumes by over 80%, as only the catheter needs to be flushed after the blood draw. Total blood and fluid volume movement with the Hummi Micro Draw system is only 1.3mL

This improved method of sampling and flushing reduces the risk of alteration in cerebral blood flow and helps the neonate to maintain more stable sodium levels during the procedure, both of which help reduce risk factors for developing IVH.

The Hummi micro draw blood transfer device is designed to further improve the safety of blood draws by reducing clearance and flush volumes by 70% compared to other current sampling methods. Hummingbird medical devices transfer fluids directly from the catheter hub to the collection device, bypassing dead space and sampling lines.

Only Hummingbird medical devices offer this specific combination of benefits and features designed to reduce IVH risk and improve NICU staffs’ infection control efforts.

Get Started with Kentec Medical Today

While many neonatal and pediatric units use the open stopcock method fairly widely, there are significant drawbacks to doing so, including an increased risk of infection for the patient and risk of blood exposure for the caregiver.

The Hummi micro draw blood transfer device is a breakthrough in neonatal phlebotomy, and Kentec Medical is proud to welcome Hummingbird Med into our family of brands and device manufacturers. Our team is also proud of our commitment to providing you with more than just high-quality devices and tools. We promise to deliver value and best-in-class service during every step of project development and implementation. Contact us today to learn more about Hummingbird Medical devices and how we can help procurement managers get them into their hospitals.

Works Cited

Elser, H. E., Holditch-Davis, D., & Brandon, D. H. (2011). Cerebral Oxygenation Monitoring: A Strategy to Detect Intraventricular Hemorrhage and Periventricular Leukomalacia. Newborn and Infant Nursing Reviews, 11(3), 153–159.

Lee, H. J., Lee, B. S., Do, H.-J., Oh, S.-H., Choi, Y.-S., Chung, S.-H., Kim, E. A.-R., & Kim, K.-S. (2015). Early Sodium and Fluid Intake and Severe Intraventricular Hemorrhage in Extremely Low Birth Weight Infants. Journal of Korean Medical Science, 30(3), 283.

Roll, C., Hüning, B., Käunicke, M., Krug, J., & Horsch, S. (2007). Umbilical artery catheter blood sampling volume and velocity: Impact on cerebral blood volume and oxygenation in very-low-birthweight infants. Acta Paediatrica, 95(1), 68–73.