blood - (May/06/2007 )
1. Is that okay to donate blood to someone or receive blood from someone without knowing its Rhesus whether it's negative or positive?
2. What types of precautions must one take to reduce the risk of bio-contamination when using, handling, or transfusing REAL live blood products? <Is that to check any viruses in your blood?>
Hope you can give me some ideas, thanks.
2. What types of precautions must one take to reduce the risk of bio-contamination when using, handling, or transfusing REAL live blood products? <Is that to check any viruses in your blood?>
Hope you can give me some ideas, thanks.
its a case to case basis. The blood from the donor and the recipient are being processed in a test called crossmatching prior to transfusion. this is a procedure where the blood serum (containing antibodies) and the red cells (containing antigens) are incubated at conditions mimicking the conditions inside the body. In this procedure, incompatibilities will be detected, irregardless whether you are Rh- or Rh+, and the extent of the incompatibility. There are cases that both have the same blood type and Rh and yet still mismatched due to the presence of other blood factors. Rh- are common to caucasians while Rh+ is common in asians.
So my point is, u dont have to worry about "without knowing its Rhesus whether it's negative or positive?" bec the lab people will determine it first prior to transfusion. And most of the time, the blood donated wil not be one to be transfused, rather a blood from the pool will be used instead. Thats why its called a Blood Bank. One thing is sure, they will find a suitable blood that exactly matches that of your patient.
In biocontamination, there is only one major precaution. and that is the "UNIVERSAL PRECAUTION". Which means treat all samples as Infectious.
Hope this helps.
Arvinsing said it right. Prior to transfusion, the blood is always cross-matched to see if transfusion can cause any reaction or not.
But, in practice in extreme emergency situation, we may have to transfuse without waiting for cross-match just noting if the blood groups are the same. My boss had done a retrospective study to see how safe it is and I cannot recollect the exact data but his small study was enough to convince us that in extreme emergency situation where we don't have time to wait for a cross-match, group specific blood may be transfused under observation.
Transfusing Rh Neg blood to Rh Pos is theoritically safe. As we know that unlike ABO we don't make Anti-D natural Ab, it is also safe to transfuse Rh Pos blood to Rh Neg if the receiving Rh Neg person has no history of exposure to the D Ag like from previous transfusion or by childbirth. (and note one more thing, it is not advisable to transfuse Rh Pos Blood to Rh Neg lady of reproductive age).
So, without knowing what is the Rh of the donor-blood, theoretically it is safe to transfuse ABO-matched blood as long as the patient is Rh Positive or if Rh Neg then if the recipient has no history of previous exposure.
About the bio-contamination, the blood banks screen by making the donor fill one questionaire and also by screening for common infectious agents like HIV, Hep B and Hep C, and VDRL. I think those are the common ones. But, there are many more blood-borne infection that can be transmitted so U cannot be always safe. So the rule is obey the Universal Precaution and do not transfuse unless there is strong indication.
Also note, always double check the label of the blood U receive from the lab and make sure the patient is getting the right one.
another cause of worry is the so called "window period" esp in HIV, thats why the lab should use very sensitive diagnostic tests....
another cause of worry is 'false negative'. . . none of the tests are 100% sensitive.
Transfusion blood usually comes from a pool as opposed to individual donors. The main concern is ABO type. R-/R+ is only important in certain instances when there is a known loss of tolerance to R. Where biocontamination is concerned the common threat is HIV. Hep virus is also a huge threat. Even if samples test negative........handle as if they are.......
clinical lab workers in hospitals should really be cautious about that...for their safety as well as the safety of recipients..In Asia there are many cases already of HIV+ blood cells that were transfused to patients bec of poor quality control and bad practices..
when i was still working in pathology lab, i noticed the big problem on diagnostic kits and reagents coming from countries and companies (i dont want to name) that comes very cheap....the thing is the quality (sensitivity and specificity) is really way below standards..(and there are so many of them in the market)
I can bear an error in my graduate school experiment say a miniprep using a cheap brand, but not an error in a diagnostic lab (e.g. HIV test) bec of poor sensitivity and specificity of the kit