CONDENSED CASE

HEMATOLOGY SECTION

 

 

  1. A 20-year-old woman came through the emergency department with unspecified complaints. A CBC was ordered and her platelet count was recorded as 17.0 X109/L. A repeat sample was ordered from the emergency department, and with this run, the platelet count was recorded as 6.0 X109/L. The patient failed to delta check with her CBC history, revealing an admission 3 weeks prior with a platelet count of 250X109/L. The technologist called the physician immediately with the report of the thrombocytopenia and inquired as to the patient history (the physician was less than cooperative; he did reveal that the patient has undergone a cardiac procedure and that the initial consensus was that the thrombocytopenia was medication induced).What additional steps should the technologist take to ensure the accuracy of this result and what will you suggest to the physician if he asked what blood component he will transfused to his patient and why?

 

Answer

 

The first step that comes to mind is to check the speci- men for clots. Improperly mixed specimens are notori- ous for containing small clots. Emergency department personnel may not be aware that blue-top tubes need to be inverted at least five times for proper mixing. This was done and no clots were observed. Next the technologist queried the physician as to whether or not this was an expected result. Although the physician was less than cooperative, he did reveal that the patient has undergone a cardiac procedure and that the initial consensus was that the thrombocytopenia was medication induced. The patient was admitted and transfused with platelet con- centrates, and the platelet count rose to 56 ?109/L. No additional history is known at this time.

 

  1. It was a busy day in the pediatric ambulatory clinic. At the change of shifts, a nurse discovered a labeled purple top tube sitting on the countertop with doctor’s orders attached. The nurse had no idea when the sample was drawn, and neither did any of the other personnel. A CBC and differential were ordered. What is the next course of action? What are the protocols in the lab that are involved with this scenario? What are the CBC parameters that can be affected if the specimen was processed?

 

Answer

 

This sample needs to be redrawn if in fact the physician is still interested in the results. CBC testing is best done within a 4-hour time period, and within 24 hours if the sample is refrigerated. Red cell morphology will be significantly affected within 2 to 3 hours at room temperature. Peripheral smears made within 12 hours on a refrigerated sample will still be viable. Testing personnel need to be aware of time limits and their effect on sample integrity.

 

  1. A 47-year-old man on a surgical floor was having daily CBCs ordered. A sample was received at 8 a.m. in the morning with the morning draw specimen. The results were delta checked and reported to the floor. Later in the day, the technologist received another sample for the same patient at 2 p.m. The results on this sample were vastly different and failed the delta check. On a hunch, the technologist retrieved the sample from the a.m. draw and took both samples to the blood bank for an ABO type. The ABO on the morning sample was type O; the ABO on the 2 p.m. sample was type A. The patient has a history of receiving O blood from the blood bank. What is the next course of action?

 

Answer

 

Proper patient identification is essential for accurate test results in the clinical laboratory. Extreme care must be taken by everyone involved in drawing and labeling a specimen to be analyzed. Samples may be drawn by the nursing staff, the physician, the infusion team, and the phlebotomist. Each of these individuals must never allow distractions or interruptions to interfere with the essential job of patient identification. In this case, the technologist called up to the surgical floor, explained the situation, and determined that the 2 p.m. sample had been mislabeled. The results on the afternoon sample were voided.

 

 

  1. At a local physician office lab (POL), one technologist was assigned to do complete differentials or to review smears depending on the automated count. She noticed that in every smear she reviewed, burr cells were a prominent part of the red cell morphology. She began to get suspicious and consider the possibility that the burr cells were artifactual. What are the potential causes for artifactually induced burr cells?

 

Answer

 

Burr cells can be artifactual if (1) the blood smears that are made are forced to air dry through repeated shaking or (2) the buffer used in staining is not at the proper pH.

 

  1. The patient in this study is a 73-year-old woman who has anemia of long standing. She had always been a poor eater. Peripheral smears have consistently shown hypochromia with target and many Howell-Jolly bodies. She has no surgical history and she shows no blood loss through either the gastrointestinal or genitourinary tract. Her lab results are WBC of 2.7X109/L, RBC 2.25X1012/L, Hgb 7.8 g/dL, Hct 23%, and MCV 111 fL. Based on these findings, what is your initial clinical impression?

 

Answer

 

This patient most likely has a megaloblastic anemia. Her age, dietary habits, and complete blood count can lead to that impression. With her dietary history, she may have initially had an iron deficiency condition, and her peripheral smear results seem to verify that. However, it seems as if her condition has shifted toward a vitamin B12 or folic acid deficiency. Serum vitamin B12 and folic acid assays should be ordered, and a Schilling test may be considered to rule in or rule out an intrinsic factor deficit

 

  1. A 6-year-old Indian girl was brought to the emergency department with a fever, malaise, and joint pain. Lab results were WBC 13,000X109/L, Hgb 9.0 g/dL, Hct 27%, and MCV 85%. Her peripheral smear revealed a moderate number of target cells, with 2+ polychromasia and moderate oat-shaped cells. Based on this sketch, what is the first diagnosis that comes to mind?

 

Answer

 

Based on her peripheral smear and the fact that she is anemic with joint pain, sickle cell anemia is a strong possibility. She needs to have this condition confirmed with hemoglobin electrophoresis or IEF. Oat-shaped cells are reversible sickle cells seen in many sickle cell anemia individuals. Obviously her bone marrow is responding because she is exhibiting polychromasia. Splenic function needs to be carefully monitored in individuals of this age group.

 

  1. A hemoglobin and hematocrit were ordered on a patient for a surgical floor. The test was performed on the Coulter LH 750, and the hemoglobin and hematocrit were compatible with previous results. However, the instrument routinely reports the complete CBC, and while observing the entire nine parameters, the operator noticed that the platelet count was only 23,000, a critical value. The delta check on the patient from the previous day showed that the platelet count was 257,000, a significant difference. Corrective action needed to be taken. The operator decided to check the tube that she has just cycled through the instrument for clots, and a small clot was found. How many times should a purple top tube be inverted once drawn to prevent clotting and what will you do next if the specimen is clotted?

 

Answer

 

The specimen that was sent from the floor was an improper sample that had probably not been properly collected. When drawing blood into a purple top tube, the tube must be inverted five to seven times for proper mixing of the anticoagulant and blood. Once the technologist noticed a small clot, corrective action needed to be taken. The technol- ogist now had the responsibility of notifying the nurse of the erroneous results and asking for a redraw. Additionally, the erroneous results needed to be removed from the computer and the documentation of the situation and corrective action needed to be recorded. The sharp eye of the technologist/technician in this case made it possible for reliable results to eventually be obtained.

 

  1. A 44-year-old woman went to her physician as part of a physical examination for life insurance. Her medical history was unremarkable, but she did complain of loss of appetite with a full feeling in her upper abdomen. She appeared to be in good physical condition but her spleen was palpable. Her physician ordered a complete CBC. In this case, the CBC revealed a 50,000 white count and a differential that showed the entire family of white cells. An LAP was ordered, and it was negative. What condition could cause an enlarged spleen?

 

Answer

 

An enlarged spleen can occur primarily as a result of hemolysis and sequestered cells or as a result of extramedullary hematopoiesis. In this case, the CBC revealed a 50,000 white count and a differential that showed the entire family of white cells. An LAP was ordered, and it was negative. This patient was diagnosed with early-stage chronic myelocytic leukemia. She was in no acute distress, but she was cautioned that since her spleen was enlarged, her movements should be restricted so as not to cause a rupture

 

  1. A 35-year-old woman needs to have an ovarian cyst removed. She had one delivery that was uneventful. Her mother has a history of bleeding after tooth extraction. The physician needs to determine if there is a bleeding disorder. She was also taking 81 μg of aspirin a day. The coagulation test results are as follows:

PT 12.5 seconds (Reference range, 10.5 to 13.3)

aPTT 32.1 seconds (Reference range, 28.7 to 35.5)

Platelets 320,000/mm3 (Reference range, 150,000 to 400,000/mm3)

Bleeding time 11 minutes (Reference, 8 minutes)

What is the most significant abnormal result in the coagulation panel? What disorder suggests this result? What is the role of aspirin?

 

Answer

 

The bleeding time is the only abnormal test, since it is greater than 8 minutes. This suggests a disorder within primary hemostasis. This can be caused by any disorder of platelets, such as von Willebrand disease, or a problem due to platelet secretion. Or it can be caused by several medications. Tests to rule out von Willebrand disease include factor VIII assay, a vWF antigen and activity, as well as platelet aggregation testing. Upon performing a platelet aggregation, there was only a primary wave for epinephrine, and no response for arachidonic acid. The patient was taking 81 µg of aspirin a day as a preventive measure. This resulted in a prolonged bleeding time. The patient was removed from aspirin and the bleeding returned to normal.

 

  1. A 14-year-old girl had a tooth extracted and was noted to have unexpected bleeding following extraction. She bled for 24 hours before the bleeding could be stopped. The dentist recommended that she have a hematology evaluation for the unexpected bleeding. What questions concerning family history should be asked, and what baseline coagulation tests should be considered?

 

Answer

This patient is exhibiting signs of mucosal bleeding, the type of bleeding seen in platelet adhesion defects such as vWD and BSS. The family of the patient should be asked about the bleeding history of family members, such as umbilical cord bleeding, circumcision bleeding, bleeding from minor cuts and abrasions, or gum or nose bleeding. The patient’s mother revealed that her sibling had serious bleeding after a tonsillectomy procedure. This fact points to an autosomal defect. Routine studies that should be ordered are bleeding time (platelet function assay), PT, and aPTT. Factor assay should be considered if the PT or PTT are prolonged.

  1. A 7-year-old child had a fall from a piece of playground equipment. After 24 hours, he developed a deep hematoma in his right thigh and his parents brought him to the emergency department to be evaluated. His family history did not give any indication of any previous bleeding from birth or otherwise. What tests should be ordered to rule out a coagulation defect?

 

Answer

Although his family history does not indicate a clotting factor abnormality, preliminary clotting tests should include a bleeding time, PT, and aPTT. This patient has a normal PT but an aPTT of 50 seconds (reference range, 20 to 38 sec- onds). A factor assay was performed and indicated a mild factor VIII activity of 40% with a reference range of 50% to 150% activity. The patient was diagnosed with mild hemophilia A. This accident brought a previously undiagnosed condition to light. This is important information in this patient’s personal and medical history. Future surgeries or traumas will need to be carefully monitored(Ciesla, 2007).

 

Ciesla, B. (2007). Hematology in Practice. Philadelphia, PA: F. A. Davis Company.

 

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