What is the most appropriate corrective action when lipemia is noted after centrifuging a microhematocrit?

When lipemia is observed after centrifuging a microhematocrit, the most appropriate corrective action is to perform a saline replacement procedure. This technique is specifically designed to address issues caused by lipemic interference, which can result in falsely elevated hematocrit readings. By replacing a portion of the plasma with saline, the lipids are diluted, leading to a more accurate assessment of the hematocrit level. This method helps to ensure that the measurement reflects the true volume of red blood cells without the interference of excess lipids that can cloud the sample.

Other options offered, while they may seem plausible in different contexts, do not effectively resolve the issue of lipemia. Conducting a reticulocyte count would not address the lipemia itself, and instead, this test is more relevant for assessing bone marrow activity or response to anemia. Re-centrifuging the sample could potentially redistribute the lipids, but it is unlikely to eliminate the lipemia and might not improve the situation. Lastly, diluting the sample with water is inappropriate, as it can lead to hemolysis of red blood cells and further complicate the analysis. Therefore, performing a saline replacement procedure is the most effective and appropriate action to take in this scenario.