Medical Technology Licensure Examination (MTLE) Practice Exam

The correct answer is rooted in the physiological responses related to blood sampling techniques. Fist pumping, which refers to the act of repeatedly clenching and unclenching the hand while the tourniquet is applied, can lead to accumulation of metabolites and a significant increase in potassium levels. As the muscles exert effort during this process, they produce lactic acid, which can lower the blood pH, resulting in a condition called acidosis. This alteration in pH is crucial because it can affect various biochemical assays and might mislead clinical interpretations.

Understanding the mechanics of blood collection helps clarify why other combinations do not accurately depict their potential effects. For instance, dilution with IV fluids could lead to altered electrolyte concentrations; however, it may not specifically decrease calcium levels as described. The incorrect order of draw is essential to know, but it typically does not directly impact sodium levels in a significant manner as stated. Similarly, prolonged application of a tourniquet can lead to increased levels of potassium and alternate analytes but does not increase calcium concentration. Each component plays a role in the integrity of laboratory results, emphasizing the importance of proper technique in phlebotomy and its implications on patient care.