Blood samples That should be Discarded (Rejected)

Blood samples that should be discarded (Rejected)

• Whenever you encounter the following possibilities, reject the sample and attempt to obtain a fresh one.

What Blood samples should be discarded?

Hemolyzed sample:

1. Serum shows evidence of hemolysis when the hemoglobin level is greater than 20 G/dL.
2. Slight hemolysis does not affect most of the test values.
3. Severe hemolysis causes a dilutional effect on these constituents, resulting in a lower concentration in the RBCs compared to the plasma.
4. There will be a marked effect of those parameters present in high RBC concentrations compared to those in the plasma.
5. Hemolysis will increase the value of:
   1. Aldolase.
   2. Lactate dehydrogenase (LDH).
   3. Total acid phosphatase.
   4. Magnesium.
   5. Potassium.
   6. Phosphate.

How will you confirm the evidence of hemolysis?

1. Serum haptoglobin is <6 mg/dL.
2. Increased serum potassium (K⁺).
3. Increased acid phosphatase and prostatic acid phosphatase.
4. Increased cholesterol

How to prevent hemolysis?

1. Ensure that the syringe and needles are dry.
2. Plastic disposable syringes are preferred.
3. Avoid rough handling of the blood. Handle the blood sample carefully and gently.
4. Remove the needle and then eject the blood into the tube. Blood through the needle will lead to hemolysis.
5. Mix the anticoagulant gently and avoid rough handling.
6. Gently transfer the blood and avoid frothing of the blood sample.
7. Before taking blood, ensure the skin is dry and clean.
8. If you apply sterile petroleum on the heel, it will prevent the spread of blood.
9. Collection of the heel prick blood, when collected in a heparinized plastic tube or a siliconized glass tube, will prevent hemolysis.
10. In the event of a delay (1 to 3 hours), store the blood in the refrigerator at 4 °C to 10 °C.
11. If there is the possibility of cold agglutinins, store the blood at 37 °C in a water bath.
12. Avoid freezing blood because, upon thawing, RBCs can lead to hemolysis.
13. Hypotonic solutions can cause hemolysis of the blood, so try to prepare an isotonic solution.

Lipemic serum:

1. Serums with lipemic appearance  will affect chemistry tests like:
   1. Phosphorus.
   2. Creatinine.
   3. Total protein.
   4. Calcium.
   5. ALT (Alanine aminotransferase).
2. Ultracentrifugation can remove the effect of lipemia.

What is the impact of Lipemia?

1. Decreased sodium (Hyponatremia).
2. Decreased potassium (Hypokalemia).
3. Increased chloride (Hyperchloremia).

What blood Samples are to be rejected?

1. The sample for CBC is unsuitable if it contains clots or is hemolyzed.
2. If there are microclots that are not suitable for Cell counting, it will give a low count.
3. If there is an insufficient blood sample.
4. If the sample is not labeled.
5. If there is a discrepancy between the sample and the request form.
6. If the blood sample is insufficient in quantity.
7. Poor handling of the sample when there is the effect of light.
8. The sample was collected at the wrong time.
9. If there is contamination of the sample.

What are the changes in the blood/serum when the vein is pressurized too much?

1. Most of the time, the tourniquet applies pressure to the vein, making it more prominent.
2. When a blood pressure cuff is used, the pressure is typically around 60 mmHg.
3. Never leave the Velcro pressure cuff on for more than one minute; it can alter blood chemistry even for a short period.

When the cuff is applied for 1 to 3 minutes, what changes will appear in blood chemistry?

What is the importance of a Blood sample?

1. The blood sample near the tourniquet has the same composition as the circulating blood.
2. Use the first sample for critical values, such as serum calcium.
3. The first tube may show a 5% increase in the protein level, while the third tube shows a 10% change.
4. In the case of slight trauma to the skin, the enzymes (SGOT) may increase.
5. In the case of stress, the patient’s body increases the production of growth hormone and cortisol.

Questions and answers: