George has been corresponding with friend and colleague, Dennis Ernst, MT (ASCP), Director, Center for Phlebotomy Education about the prevalence of hemolyzed specimens from the Emergency Department (ED) compared to hemolysis rates from other units. Dennis and George agree hemolysis is related to the practice of collecting laboratory blood specimens at the time the nurse starts an IV, and that hemolysis occurs when small gauge catheters are used (24-gauge) in combination with excessive negative pressure during blood collection.
Dennis responds: It is my understanding hemolysis is inherent with all IV devices. It is also my understanding that using such devices for drawing labs is using it off label. IVs are not designed for drawing labs, but for infusing fluids. The needles are just not red cell friendly. I would bet a dollar the FDA has not approved this device, or any IV device, for blood sample collection. In fact, the Infusion Nurses Society released their revised standards in January, and recommend performing a separate venipuncture for lab samples rather than drawing during an IV start, citing hemolysis. I reported on this in my August newsletter.
Additionally, the CDC did a comprehensive literature review to find Best Practices to reduce ED hemolysis. I was part of the evidence review panel. In 2012, they made it a Best Practice not to draw labs during an IV start. Here’s a link to the article summarizing their recommendations, which I co-authored. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4518461/.
That said, the practice of drawing labs during an IV start is entrenched in the industry. Hemolysis will always be a problem regardless of the brand. You can minimize it by 1) using low-volume tubes when drawing directly from the line through a tube-holder adapter; 2) pulling slowly on the plunger of the syringe, if used; and 3) drawing only from large-gauge cannulas. One study found hemolysis occurs 100% of the time when drawn through 24-gauge cannulas, but only 10% of the time through 18-gauge.
I would recommend watching my video “Ending Hemolysis in the ED… and Everywhere Else.” The page has a preview for you to view. I also have a six-page document summarizing the literature on draws during IV starts here: http://www.phlebotomy.com/product/6405.cpe. I hope this helps.
More from George: Here is a 5-minute visual from B. Braun Medical, Inc., that illustrates the technique nurses use to start IVs. George speculated that nurses may collect blood specimens through the metal insertion needle prior to removing it from within the catheter, given that the needle has a Luer hub. Since the needle bore is of necessity narrower than the catheter, this practice could account for hemolysis. George checked this idea with friend and colleague, Laurie Nabors, RN, who says no, the standard nursing practice is to remove the needle, attach the short extension (“pigtail”) tube to the catheter Luer hub, and then collect blood from the pigtail before attaching the IV tubing. In this case, the hemolysis is, as Dennis states, the result of the combination of a narrow gauge catheter and excessive negative specimen collection pressure. The apparent reason for lower hemolysis prevalence in units other than the ED, such as ICUs, is that nurses there are able to collect blood from established vascular access devices.
Laurie also agrees that, regardless of guidelines, most nurses collect laboratory blood specimens from the IV set (as Dennis states) because ED patients often present with small fragile veins. It takes considerable skill to locate and successfully establish access to a “good” vein. Having helped with ED IV starts, George confirms that the process can be challenging, often requiring two or three attempts. Perhaps a more compelling issue is concern for patient comfort and safety.
What is your experience? Do you find that ED specimens are more likely to be hemolyzed than ICU specimens? Do your ED nurses are collect blood while starting IVs? Do you have a solution other than those Dennis presents? Please provide your anecdote below. (Geo).
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