Abkhazia Institute for Social and Economic Research

It’s a new name for an old concept that’s getting fresh attention due to an awareness of what can happen when people underestimate blood specimen collection procedures as a cause of false lab results and patient injury. Best practices also encompass policies and procedures to ensure specimen integrity. For example, the tourniquet creates a "fishnet" effect when left on the arm too long, and it can drive up the specimen’s concentrations of potassium, glucose, cholesterol, albumin-even blood cells. Lactate levels are also sensitive to tourniquet time-repeat testing on either venous specimens collected with very short tourniquet times or arterial specimens has produced lower lactate results.
Collection and potassium readings  
Specimen collection techniques can bump up potassium readings by 1-2 mEq/L. And the errors can seem like little things, such as leaving the tourniquet on too long, filling the blood collection tubes in the wrong order, or allowing the patient to pump his or her fist during the venipuncture. Potassium levels also creep up in specimens that sit around too long before centrifugation. A patient were really hypokalemic, the extra potassium added from these errors-for example, due to cross-contamination from a blood tube with a preservative, EDTA-can drive up the potassium into the normal range. And that can be tragic for the patient whose potassium is really too low for surgery, even though the lab result shows a normal level. That patient can die during surgery.