Hey people! This is Siew Ming here to post again (:
I am going to post about my experience when I was attached to the Hematology lab.
Basically, the hematology lab is being divided into two sections: 1) Stat lab where emergency samples were being handled and 2) Routine lab whereby routine processing of blood samples are carried out.
I got the chance to observe and participate in the various tests that are carried out in the lab, such as FBC, ESR, reticulocyte Test, Kleihaur Batek Test and APPT/PT. Besides these, I felt fortunate to be taught to recognize and differentiate the different types of blood cells under the microscope by a very senior med tech! (:
Today, I’m going to share about the techniques of Erythrocyte Sedimentation Rate (ESR). ESR is a screening test used to detect inflammation. However, confirmatory tests have to be carried out to confirm the diagnosis. ESR refers to the rate at which the red cells sediment over time. It is often measured in mm/H. ESR will increase when there is infection, pregnancy, SLE, Anaemia, etc.
For a single ESR test, a minimum of 350ul of venous blood will be collected in an EDTA tube. Before performing the test, it is very crucial to check for visible clots of the blood. This is because clotted samples cannot be processed and the results will be inaccurate and not valid.
Steps:
1. EDTA blood sample is mixed well by inverting the tube several times.
2. 320ul of blood from the EDTA tube is transferred into a Aquisel Tube (filled with Trisodic Citrate 0.106M)
3. The Aquisel tube is then mixed for at least 12 times.
4. A pipette is then introduced into the Aquisel tube through a twisting the pipette in a circular motion, and gradually push the pipette downwards to allow blood to fill the pipette. The blood level should reach the “0” marking on the pipette.
5. The pipette, together with the Aquisel tube is left to stand on a Styrofoam Aquisel Tube holder for 50 mins.
6. Results (no. of mm the cells have fallen) were read at the end of 50min.
7. Results were then recorded into the ESR record book, patient’s request form and LIS verification system.
The expected ranges should be:
Neonates (1-2days): 0-4
Neonates (3 days-1 month), children (2 months – 12 years), and adults (more than12 years): 0-10
I think there is something wrong with blogger these few days. As it doesn’t allow me to post pictures, here’s a link to show how do Aquisel tubes and pipette look like: http://www.swissvacuum.com/products/selecta/Biology_and_histology_equipment/DivisionAnalytique.pdf
Subscribe to:
Post Comments (Atom)
Hello,
ReplyDeleteWe have learn in haematology classes about full blood count, Retic count,erythrocye sedimentation rate, peripheral blood film, PT and APTT but what is a Kleihaur Batek Test and what is it use to detect ?
Stanley
Hi stanley!
ReplyDeleteGlad you ask! :D
The Kleihauer Batke test or KB test is a method used to detect Fetal-Maternal Hemorrahge (FMH) by identifying HbF of the foetal RBCs. In FMH, the foetal blood will be transferred into the mother's bloodstream.
From here, KB test can determine the degree of FMH through the detection of foetal RBC in the maternal fetal blood.
In this technique, the foetal RBC will take up the eosin satin and appear as darkly red stained cells. In contrast, the adult RBC will be disintegrated and appear as palely stained ghost cells.
So under the microscope, we will look out for the pinkish foetal RBCs rather than the pale adult RBCs. (:
Hope this helps!
Cheers,
Siew Ming
HEYS!
ReplyDeletecan i just ask, what are the tests conducted in the stat lab?
and u mentioned that ESR is a screening test and confirmatory tests have to be carried out to confirm the diagnosis, what are these confirmatory tests?
cheers,
Ang Yu Hui
0702632A
hihi,
ReplyDeletei would like to know why clotted specimen cannot be processed and the results are inaccurate and invalid.
Yeo Sok Kian Jocelyn
0703359J
hi siew ming:)
ReplyDeleteMay i ask what is the reason behind the lower expected range of neonates(1-2days)than others?
Also, how can you control the blood reaches the marking '0'..? Coz i remembered i did that in that lab, and i overshoot it:P
Thanks a lot!
eriko
0700477C
Hey Siewming,
ReplyDeleteIs there a range for pregnant women and does ESR vary during the three trimesters?
Yvonee
0703189A/Group 8
Hi Siew Ming.
ReplyDeleteFor performing ESR test, the time used is 50 minutes to complete the test.
So, is it the same for both routine and urgent samples?
Or do you have another method for urgent cases of ESR to reduce the turnaround time?
ENJOY yr SIP =)
With Regards
Jordan Wong Wei Jie
0703992H Group 09
Hi Siew Mai.
ReplyDeleteOne more question.
Lets say if this patient, who requested for ESR, FBC and Bood Group test, and theres only one EDTA tube.
Is it sufficient to perform all three tests?
With Regards
Jordan Wong Wei Jie
0703992H Group 09
TG02
REPLY:
ReplyDeleteHi Yu Hui,
The tests that are conducted in the STAT are only FBC and staining. STAT lab will process the samples have shorter turaround time like urgent samples from the ICUs, Children Emergency, and paediatric finger prick samples.
ESR is just a screening test for the presence of inflammation.
Normally, the type of confirmatory tests to be done will depend on what is the condition of the disease and doctor's diagnosis.
For example, if it is suspected that the patient has inflamation, and the ESR test results supports the initial diagnosis made by the doctor, the doctor will then order the confirmatory tests that will help in the confirmation of the disease.
Hope this helps!
Siew Ming
REPLY:
ReplyDeleteHello Jocelyn!
As we know, ESR is to test for the sedimentation rate of the RBC. So if we were to use clotted samples, the cells are already packed and clotted together. This will affect the results.
So in the first place, when we receive any clotted samples, we are not suppose to perform ESR on them and will have to call back to request for a new tube of blood.
Cheers!
Siew Ming
REPLY:
ReplyDeleteHi Eriko!
Neonates who are 1-2 days old have lower ESR because their Hb levels are much higher (14 to 20g/dL). High Hb indicates they have a higher packed cell volume. With a higher packed cell voulme, ESR will be lower.
And regarding on the technique of filling the pipette to the "0" marking, there isn't much control needed. I guess the previous time you could have transferred too much blood into the Aquisel tube, thus overshooting.
In the lab, we only transfer about 320ul into the tube and it'll be just nice.
Hope this helps! :D
Siew Ming
Hello Yvonee,
ReplyDeleteIn the lab, they do not do ESR for pregnant women. This is because ESR is always elevated in pregnancy. Hence, even if ESR is performed, it has no significance.
Also, ESR is only a non-specific screening test for inflammtion and it will not help much for diagnosing any abnormal conditions of the pregnant patient. As such, more relevant and specific test could be done if needed.
Thus, in the lab, there is no ranges for Pregnant women. (:
Hope I answered your question!
Siew Ming
Hey Jordan!
ReplyDeleteThank you for your questions!
Yes, an ESR test takes 50 mins to complete for both routine and urgent samples, and there is no other alternatives for reducing the ESR time.
There turn around time for ESR test in the lab is about one and a half hours.
For your seond question, one EDTA tube is enough to do FBC and ESR. The EDTA tube used in the lab is 5ml. FBC will take around 250ul and ESR will use 350ul. So in all, about 600ul will be used. If the lab were to receive insufficient blood, they will call up and request more blood to be taken.
Oh, and the haematology lab do not do blood grouping. Blood bank will do the job, and they will have another blood tube from the patient for that.
Cheers!
Siew Ming
hi siewming,
ReplyDeletewhy is there an increase in ESR in example pregnancy? does that means there is increase chance of inflammation in this case? :S thanks!
zi shuang :)
REPLY
ReplyDeleteHey zi shuang :),
There is an increase in ESR during pregnancy as there will be an increase in the number of plasma globulins and fibrinogen. An increase in plasma globulins and fibrinogen will cause the red cells to stick together, thus falling faster and increasing the rate of sedimentation.
In addition, an increase in ESR may also means that there is inflammation. Inflammation will also result in an increase in the levels of globulins and fibrinogen. Hence, increasing the rate of sedimentation.
Also, ESR is just an indirect screening test for inflammation; it does not tell us the chances of the patient getting inflammation. If there is an increase in the sedimentation rate, it is possible that there is inflammation. On the other hand, if the sedimentation rate falls within the range, there is no inflammation present.
Hope I answered your questions.
Siew Ming
Siewming,
ReplyDelete(1) From my read-up about ESR, the basal ESR is slightly higher in females compared in males. Why is it so?
(2) Besides its screening, can it be used for the prognosis of patient?
Li Yinliang Alex
TG02 0704894E
Group 8
19 August 2009
Hi SiewMing,
ReplyDeleteYou mentioned that if sedimention rate increase = inflammation. And falls within the range = no inflammation. How about if the values decrease? What does it shows?
QINGLING
Reminder
ReplyDeletePlease reply to questions within 2 weeks, or else your posting will be disregarded.
I apologise for the late replies! ):
ReplyDeleteAlex:
(1) From my research,I think women have a higher basal ESR because they have higher levels fibrinogen in them. Fibrinogen will cause the RBCs to stick together, thus, causing them to fall faster. In addition, menstruation and pregnancy will also cause elevations of the ESR.
(2) As I've mentioned, ESR is just a non-specific screening test for the presence of inflammation. Hence, it will not indicate to us the prognosis of the patient.
Qing Ling:
If there is a decrease in ESR, it means the patient may have diseases like sickle-cell anaemia, hypofibrinogenemia, congestive heart failure, etc.
Siew Ming
thanks for sharing very informative information with us...if you want to order an online blood test then visit:
ReplyDeletehttp://www.mediangels.com/TestDone.aspx
Dr. Suzy Melkonian has been providing high quality medical services in Hematology and Oncology in the Mission Hills, Porter Ranch, and the Greater San Fernando Valley for over 20 years. Hematology
ReplyDelete