The Art of Hemolysis

Know-How The Art of Hemolysis

Know-Howed is such a pretty color... unless it While hemolysis brings a splash of color to a speci- circulating in the patient. It’s as different as night men, it’s the art of preventing hemolysis that is and day. Because red blood cells contain 23 times tinges the serum or plasma of the the subject of this Needle Know-How. Hemolysis as much potassium as the liquid portion of the specimen you collected. Then it’s has been reported to be the number one cause of blood, when red cells rupture during collection, the R rejected chemistry specimens. In fact, six times specimen being submitted for testing is spiked with ugly. It’s ugly because it usually means more specimens are rejected because of hemolysis potassium. In fact, it’s spiked with so much potassi- than the second-most common reason, insufficient um that, if tested and reported, the results can send the time you spent drawing the specimen sample volume. But before we master the art of the physician into a sheer panic, forcing him or her was wasted and the draw will have to be preventing hemolysis, we have to understand how to react with orders that can be ultimately unfavor- repeated. But it’s more than a time killer. it occurs. able to the patient. Or, if the patient’s circulating “Hemo” means blood, of course; “lysis” means to potassium is actually too low, hemolysis can spike Having to recollect a hemolyzed specimen rupture or the destruction of cells. So hemolysis is the specimen into a normal range and lead to inac- literally the destruction of blood cells, specifically tion when action is necessary. that is incapable of rendering accurate red blood cells. When red cells rupture, they spill But it’s not just potassium that hemolysis affects. and useful results to the physician delays their contents, mostly hemoglobin, into their sur- These other tests are affected when hemolyzed roundings. Hemoglobin is a respiratory pigment specimens are submitted for testing: LDH, AST, treatment, diagnosis, and/or much-need- that has a has an insatiable passion for oxygen and ALT, phosphorous, magnesium, ammonia, RBC, ed medications. In critical situations, time gloms onto every molecule of it that it can hold hemoglobin and hematocrit. Not only these ana- while passing through the lungs, then dumps it off lytes, but virtually everything that could be tested. isn’t just money, it can be life itself. into the tissue where it’s needed for cellular func- That’s because besides hemoglobin is a liquid pro- tions. tein which dilutes the serum or plasma being tested. Hemoglobin is also what makes blood red. So The greater the hemolysis, the greater the dilution. naturally, when red cells burst, it tinges the liquid Suffice it to say hemolysis is just all-around nasty. portion of the blood. So how do those who collect specimens prevent If red cells burst during specimen collection, the the lab from reporting inaccurate results? Sure, the blood being tested is not the same as the blood testing personnel should be rejecting hemolyzed

Know-How specimens when they receive them, but by the time Don’t rim clots—When specimens are centrifuged stated volume and that smaller volume tubes are hemolysis is detected, the time spent drawing the too soon after collection, fibrin in the serum has to available for those situations when a difficult draw specimen is already wasted and the delay in report- be removed. Often the technique used by specimen is anticipated. ing accurate results is already taking a toll on pa- processors is to “rim” the clot with wooden appli- Using these and other techniques can minimize tient care. So preventing hemolysis in the first place cator sticks. This technique not only ruptures red your potential to hemolyze specimens. Since ac- has enormous benefits to the patient. Follow these blood cells bound up in the clot, but also exposes curate results begin with the collector, those who guidelines to keep your personal specimen rejection the processor to bloodborne pathogens. Instead, draw blood specimens are in the best position to rate to a minimum: allow specimens to clot for 20-30 minutes before make sure patients are treated according to results Avoid line draws—Vascular access devices (VADs) centrifugation. that are not delayed or altered because of hemoly- like central venous catheters and PICC lines are Place the needle properly—Should the bevel of sis. The real art of hemolysis is in avoiding it in the designed primarily for fluids to be infused into the needle rest half way through the wall of the vein first place.• the patient, not blood to be withdrawn. The shear or the vacuum of the draw partially collapse the forces and turbulence generated through such vein, the opening of the bevel is narrowed by the If you’re looking for training materials to teach your systems is often too much for the fragile red cells obstruction. A partially obstructed needle opening staff and students how to reduce hemolysis, consider to handle, making hemolysis unavoidable in all results in a dramatic increase in the shear forces at Ending Hemolysis in the ED...and Everywhere Else avail- but the largest-diameter canulas. When there is a the tip of the needle, hemolyzing the cells that pass lack of alternatives, use a syringe and gentle pull- through. When the blood flow appears abnormally able in DVD or streaming. ing pressure on the plunger. But be prepared to slow, attempt to relocate the needle for a more We also offer a variety of preanalytical Smart- perform a venipuncture anyway. If you must draw central placement within the vein. But always fol- ChartsTM for printing and posting on hemolysis, draws from a VAD, attach a red-cell friendly device like low the limits of needle relocation as defined in the during IV starts, analyte stability and troubleshooting PIVO (Velano Vascular), which has been shown to NCCLS standards to prevent patient injury. potassium problems. significantly reduce hemolysis in line draws. Prewarm skin puncture sites—Nothing hemolyzes Visit www.phlebotomy.com Avoid vigorous mixing—Gently invert tubes a capillary specimen like excessive “milking” of the with additives instead of vigorously mixing them. tissue. To prevent the necessity to milk the site, pre- Remember, red blood cells are delicate and don’t warm the area with a warm compress not to exceed handle stress too well. 42 degrees Celsius. This increases the flow of blood Avoid excessive pulling pressure—When drawing through the area seven fold. into a syringe, pulling back hard on the plunger of Fill tubes fully—When collection tubes with anti- the syringe causes too much turbulence through the coagulants are underfilled, the excessive concentra- needle and ruptures red cells as they pass through. tion is hard on the fragile membranes of red blood Use a gentle pulling pressure instead. cells. Make sure that all tubes are filled to their