correction – Flashcards

High numbers of WBCs can cause a false decrease in the WBC reported. To correct a high WBC count: 1. WAM holds results. 2. Perform a 1:5 dilution of the specimen (Add 100 mcL of specimen to 400 mcL of CellPack diluent.) 3. Run on capillary mode of instrument within 20 minutes of setup. (See CBCD and Reticulocyte procedure). As a QC check, verify that the RBC count agrees within + 0.1 of undiluted sample. If not, rerun sample. If still not acceptable, remake dilution. Notify supervisor if unable to resolve. 4. When run in the capillary mode, the instrument automatically multiplies the results by 5 and sends them to WAM. 5. Accept the WBC count if the RBC count agrees + 0.1 of original RBC count. 6. In WAM, add internal comment "By dilution". NOTE: The HGB and WBC are measured in different chambers on Sysmex analyzers, so there is no WBC interference with the HGB result

Cold agglutinins cause the spontaneous agglutination of RBCs at temperatures lower than 37oC. The degree of agglutination is dependent on the cold agglutinin titer. Due to the fact that the Sample Rotor Valve (SRV) on the Sysmex analyzers is warmed to 37oC, only strong cold agglutinins will be apparent. The strong cold agglutinins will cause spurious low RBC counts due to counting micro-agglutinates as single cells. Also, the MCV will be falsely elevated due to micro-agglutinates being sized as a single large cell. The hemoglobin reading is usually correct. Also, with a correct hemoglobin value and low hematocrit, the MCHC (Hgb/HCT x 100 = MCHC) and the MCH (MCV x MCHC/100 = MCH) will be spuriously elevated. Check for cold agglutination on all bloods with: (a) "MCHC" greater than 38%; (b) smear and hematology analyzer MCV do not agree (NOTE: MCV does not necessarily have to be macrocytic to be suspicious of a cold agglutinin); (c) smears with RBC agglutinates; or (d) any blood you are suspicious of because of a "lacy" appearance in the tube or on the slide. If b, c, or d is present, follow cold agglutinin procedure, regardless of MCHC value. To correct for the effect of a cold agglutinin: 1. Place the blood in a 37oC incubator (e.g., heating block or coagulation water bath) for at least 15 minutes. 2. Mix specimen thoroughly and rerun the blood through the open mode of the hematology analyzer. (So specimen doesn't cool down). 3. Report the 37oC results (for all parameters) if the MCHC is feasible. (See Figures 1 and 2 below.) 4. In WAM, add "Possible Cold Agglutinin" comment by double clicking on COM field next to MCHC result and selecting HE03, then SAVE. 5. For a cold agglutinin specimen that has instrument flags/lab values requiring microscopic review: If RBC agglutinates are present, make warmed smears to see if the agglutinates go away upon warming. Regardless of which smears (room temp or warmed) exhibit agglutinates, report "RBC agglutinates present". If case needs further review by a pathologist, submit both sets of clearly marked slides to the pathologist. NOTE: Cold agglutinins must always be incubated at 37oC before being reporting as such.

can cause a falsely elevated hemoglobin due to a cloudy SLS-hemoglobin solution which decreases the amount of transmitted light through the solution to the photocell. (Lipemia usually occurs in patients with hyperchylomicronemia whose triglycerides are greater than 1,000 mg/dL.) Lipemia should be suspected on all bloods with: (a) a lacy appearance of blood smear or (b) an MCHC over 36.5. Action must be taken on MCHCs greater than 38%. To check for lipemia, spin blood for approximately 5 minutes (or let settle for approximately 10-15 minutes) and visually check plasma layer for characteristic milky appearance. To correct for lipemia perform either of the following procedures: Plasma Replacement: 1. Spin down a PORTION of the blood specimen at 2000 rpm for 5 minutes. 2. Mark the top (meniscus) of the plasma level. 3. Carefully remove most, but not all, of the plasma. 4. Replace the plasma with the same amount of Cell Pack diluent (add diluent up to the mark). 5. Mix the sample and cycle through the instrument. 6. Use the RBC result as a guide to verify proper re-dilution of the specimen. 7. If the RBC result is within + 0.10 of the original RBC, report the Hgb, from the re- diluted sample. 8. Recalculate the MCH and MCHC using the new HGB and original RBC and HCT.

1. Spin a portion of the blood. 2. Perform a hemoglobin on the PLASMA using the hematology analyzer open mode. 3. Use the following formula to calculate the correct hemoglobin: Corrected HGB = Original HGB - [(1-{Original HCT/100}) x Plasma HGB] Example: WBC 5.1 RBC 4.03 HGB 16.1 HCT 39.3 MCV 97.5 MCH 40.0 MCHC 41.3 PLT 250 Plasma Hgb 4.5 Corrected HGB = 16.1 - [(1-[39.3/100]) x 4.5] = 16.1 - [(1-.0393} x 4.5] = 16.1 - [0.607 x 4.5] = 16.1 - 2.7315 = 13.4 4. Recalculate the MCH and MCHC using new HGB and original RBC and HCT. Corrected report: WBC 5.1 RBC 4.03 HGB 13.4 HCT 39.3 MCV 97.5 MCH 33.3 MCHC 34.1 PLT 250 5. In WAM, add "Corrected for Lipemia" comment by double clicking on COM field next to MCHC result field and selecting HE02, then SAVE. (See Note 1.) NOTE: To avoid any math errors, have second technologist verify calculations.