CASE NOTES 6. - Blood
RADIO 4
TUESDAY 11/05/04 2100-2130
PRESENTER: MARK PORTER
REPORTER: TRICIA MACNAIR
CONTRIBUTORS: JEAN HARRISON
DAFFYD THOMAS
ANDY EMERY
KEITH PATTERSON
PRODUCER: HELEN SHARP
ACTUALITY - BLOOD CLINIC
PORTER
Today's programme is all about blood and I'm lying on my back in the West End Blood Donor Centre, just off Oxford Circus, halfway through giving my first unit of blood for 20 years, I'm embarrassed to say, and so far so good.
NURSE
How are you feeling?
PORTER
I'm feeling fine actually.
NURSE
Are you?
PORTER
Thankfuly.
More from my donor session later in the programme.
As well as finding out, first hand, what it's like to give blood, I'll be discovering how the thousands of units collected every day are used and how recent changes to the rules for would be donors mean that the Blood Service is finding it harder than ever to match supply to demand.
I'll also be looking at the latest techniques for reducing the need for transfusion in patients undergoing surgery - good for both the Blood Service and for the patient you'd think, so why aren't they used more often?
Andy Emery's wife offered to donate some of her own blood in the weeks before her operation so that it could be transfused back into her after surgery if she needed it but the hospital weren't that keen.
EMERY
They said to her that if she was insistent on having it then there could be a strong chance that the operation would be delayed. Well at this time she was in an awful lot of pain and she opted to go ahead with the operation, possibly thinking that there was also a fairly good chance that she wouldn't need a transfusion.
PORTER
My guest today is Dr Jean Harrison who is a consultant haematologist at the National Blood Service.
Jean, what's blood made up of?
HARRISON
Well there are three types of cells in blood - red cells which contain a red pigment called haemoglobin which carries oxygen round the body white cells which fight infection and make antibodies and platelets which are part of the clotting system.
PORTER
And they're all floating around in what?
HARRISON
And these float in plasma which contains protein and clotting factors and various other proteinaceous materials, which basically keep the blood within the circulation.
PORTER
What about blood groups - where do they come into the equation?
HARRISON
Well the common blood groups are proteins which are inherited and they are on the surfaces of the red cells and there are - the four main blood groups A, B, O and AB are also inherited and they're very important because you cannot mix one group with another. Then there are other minor blood groups - there's the rhesus group, or RH group, which most people have heard of, which is another blood group system.
PORTER
This is rhesus positive or rhesus negative?
HARRISON
Yes, that's quite a complex system, also inherited and there are various other blood types which are less important when matching blood for transfusion. We don't know why we have blood groups, in fact if God had given us no blood groups it would be much easier, life would be much easier for us.
PORTER
What actually happens then if you give somebody the wrong blood group?
HARRISON
Well if you give somebody incompatible blood it can kill them. The reason for this is that with the A, B, O and AB groups there are also naturally occurring antibodies in the plasma, so that if - like me - you're group A you have anti-B in the plasma, if you are group O you have anti-A and anti-B. So if you are a group O and you're given blood of group A the blood will sort of clot and clots can be deposited in the kidneys and the blood vessels and it can even cause death.
PORTER
Where's blood made?
HARRISON
Blood is made in bone marrow. In adults it's made in the bones of the hips and torso and not in the long bones - not in the arms and lets - it's a sort of factory and …
PORTER
And that's where all the components - the white cells, the red cells and the platelets come from?
HARRISON
Some of the white cells are thought to be made in lymph nodes but most of the blood is made in the bone marrow - the red cells, most white cells and the platelets.
PORTER
And how much blood does the average person have within their system?
HARRISON
Well a small woman would have about three litres and a large man five or more litres.
PORTER
Thank you for the moment Jean.
The National Blood Service is the part of the NHS responsible for supplying blood and blood products to hospitals across England and North Wales for use in patients with a wide range of problems - everything from blood loss after giving birth, to anaemia following chemotherapy for cancer.
As of this morning they currently have just over 30,000 litres (that's 54,000 pints) in stock. That may sound a lot, but for some blood groups that's barely enough to last until the weekend.
In the last 12 months the National Blood Service has collected, tested, stored and distributed 2.5 million donations - including one of mine.
ACTUALITY - BLOOD CLINIC NURSE
If you'd like to make yourself comfortable on the couch. I gather it's your first time for some years.
PORTER
Twenty years I'm embarrassed to say yeah.
NURSE
Right.
PORTER
So how much blood will you be taking from me?
NURSE
Four hundred and seventy mils.
PORTER
That's about a pint.
NURSE
And then we've got to collect samples from you as well during that - so that's another 50 mils.
PORTER
All through the same needle I hope.
NURSE
Oh yes, yes.
PORTER
It's a bit of a cliché but how many of the people who come here are actually worried by the needles?
NURSE
I'd say everybody is to a degree including myself.
PORTER
Well I'm glad you get it because I can wield them without any problem at all but when I'm on the receiving end I'm not so keen but then who is I suppose. So what's actually going to happen to my sample that I've been given today - how is it likely to be used?
NURSE
Well it'll go to any hospital that requires the unit, so once it's been processed and they've allocated you with a blood group and all your testing's been done it will then go out for issue and wherever it's needed it will be sent to.
PORTER
But because this is my first donation for a while you won't be using all of the blood will you?
NURSE
No, we'll be using the red cells and the plasma.
PORTER
So that means that you'll be - what - filtering out the platelets the little tiny ones?
NURSE
Yes, they won't actually be used and they deplete the white cells as well - so they take those off as well.
PORTER
But once I'm on the system again and I become a regular donor you can do anything you like with the blood - you can use whole blood or …
NURSE
We just follow the daily instruction list as to what we need to collect - what groups in.
PORTER
Presumably that reflects the need that's out there, so if they're a bit short of something they might ask you to collect more of a certain type of blood.
ROBERTS
Ian Roberts.
PORTER
How long have you been giving blood for?
ROBERTS
I started back in August 2002, so almost two years.
PORTER
And why did you become a donor in the first place?
ROBERTS
It was after a friend of mine, well a late friend now who went down with cancer, amongst chemotherapy sessions was having blood transfusions and so on and so forth, I thought alright go down the local centre and give a donation.
PORTER
How do you find the actual donation, does it bother you at all?
ROBERTS
Apart from a slight phobia of the sight of needles I'm alright.
PORTER
And how long does it actually take?
ROBERTS
Five, 10 minutes when you're actually on the slab so to speak.
PORTER
Obviously losing a friend to cancer is - it's a big driver for this sort of thing, have you been on the receiving end yourself from any blood products?
ROBERTS
No not yet, hopefully never will but you don't know what's round the corner.
NURSE
Okay, what'll actually happen now - the cuff will go up, just so that we can actually get a vein …
PORTER
Right, yeah, a tourniquet. The bit I've been looking forward to. So the tourniquet's brought up my vein.
NURSE
It has indeed.
PORTER
And that looks like the needle.
NURSE
Okay just relax now. It will actually feel very sharp.
PORTER
Okay, in it goes. And it's in. And that's not that bad actually, I'll be honest.
NURSE
And if you'd just like to gently sort of wiggle your fingers.
PORTER
Yeah, the needle's in but I can't feel it now.
NURSE
The arm might feel, sort of after a few minutes, it might feel sort of a dead weight.
PORTER
Yeah, and here comes the blood.
NURSE
Do you think you'll actually be back after today?
PORTER
Yeah, no I should do really, I mean I'm bit like - I'm a bit embarrassed that I don't do it more.
NURSE
What actually happens after today, once all the information's been put on to what we call …
PORTER
So I can go to my local centre and …
NURSE
Yeah, you can have call up letters sent to you nearest to your home or you can sort of just return here at 16 weeks time. You will actually be reminded by - what'll actually happen is a BHC [phon.] will actually come through the post offering you a session.
PORTER
An invite.
NURSE
Your invite yeah and you can actually book an appointment - whatever's your convenience or you can just walk in at any time during our opening hours.
PORTER
How are we doing?
NURSE
Lovely. You've got - that's 80 mils to do.
PORTER
It's all cleverly structured here because I'm lying flat on my bed looking up at the ceiling, I can't see a thing, I can't even see the needle or the blood …
NURSE
This machine actually here, this is a fairly new one, but we've actually got it programmed to cut off at 470 mils and it'll actually alarm to us to say that you've finished your donation and we then sort of go through taking down the procedure.
PRESS
My name's Ian Press.
PORTER
How long have you been a blood donor?
PRESS
I think I've been a blood donor since about '72, 1972, so 32 years or so.
PORTER
And how often do you donate?
PRESS
As often, on the whole, as I'm told to come and give it, I'm two weeks late at the moment that's because I had viral infection so I just had to wait for that to clear.
PORTER
Why did you become a donor in the first place?
PRESS
I think I just come from a family where one tended not to do that sort of thing and I think other members of my original family are still quite squeamish and it was one thing I could do somehow, so I just went - came along, it was in Walthamstow, I went along to Walthamstow one day and registered and started giving. And on the whole I've given regularly since.
PORTER
And how do you feel afterwards?
PRESS
Fine, I've never collapsed. I don't notice any difference whatsoever. I try to be careful and obey, like no strenuous exercise, I don't smoke and I never have smoked, so that's not a problem. They did use to give you some Mackeson or something like that afterwards and I've just complained about that, as I usually when I come, but they advise against alcohol for a few hours.
PORTER
I see you're availing yourself of the tea and biscuits.
PRESS
Mmm yeah, oh absolutely yes, it's one of the reasons to come here.
PORTER
Have you ever been on the receiving end - have you actually ever received any blood yourself?
PRESS
No I haven't no, no I've been very, very lucky, I've never had anything - shouldn't have said that should I.
NURSE
Well you've finished now. Feeling alright?
PORTER
Yeah it feels fine.
NURSE
Didn't feel a thing did you?
PORTER
Well I did feel something but nothing that …
NURSE
No nothing …
PORTER
Certainly didn't know it was in there the whole time it was in there, just sort of a sharp sting. I'd say the worst bit of it taken out was the moving the plaster that was holding it in, pulled one of my hairs out.
NURSE
Okay we have an advise card that we actually - we ask that you read.
PORTER
Okay.
NURSE
On both sides.
PORTER
Okay, so after you've given blood, it says, please take it easy for at least 10 minutes and enjoy some light refreshments before you go - that's the tea and biscuits presumably is it?
NURSE
No tea but sort of soft drinks today.
PORTER
Oh right.
NURSE
Biscuits.
PORTER
Drink plenty of fluids (non-alcoholic), leave your plaster on for at least six hours, that's the plaster over the wound, take care of your arm by avoiding heavy lifting for the rest of the day, avoid activities which may present a hazard to you or others if you happen to start feeling weak or light headed. What about driving? What's the standard advice for people who have - because a lot of people …
NURSE
There isn't any really, I mean you've obviously - everybody knows their own limits don't they and if you're not feeling well then you're not actually going to jump into a car are you and you know the reason you're not feeling quite right is because you've given a donation.
PORTER
And that's because your blood pressure, presumably, has a tendency to drop a bit. How quickly - how long is it before people - the body corrects that - after you've given the unit?
NURSE
For fluid loss 24 hours, as long as you take lots of fluids, soft fluids and for your iron, it can be anything up to 6 to 12 weeks and that depends on your diet, so that's the main ..
PORTER
And the last two points - if the bleeding recurs raise your arm and press on the donation site for at least five minutes and if you feel faint lie down immediately and rest until you feel better.
NURSE
And we'd like to offer a cold drink of orange, lemon or water.
PORTER
An orange please.
Well thank you to the staff at the West End Donor Clinic for making it all so painless!
You're listening to Case Notes, I'm Dr Mark Porter and I'm discussing blood with consultant haematologist Dr Jean Harrison.
Jean - recent changes in the rules as to who can become a donor have made things a bit more difficult for the National Blood Service haven't they.
HARRISON
They have indeed. Basically people can give blood if they're fully fit and they're not at risk of transmitting any blood borne disease. But recently we've changed our rules so that anybody who knows that they have received a blood transfusion since 1980 in the UK cannot act as a donor.
PORTER
And why is that?
HARRISON
The reason for this is it's a precautionary measure. Ever since the BSE was recognised in this country there was then the risk that humans might get a form of BSE and that is variant CJD. Now this is a very rare condition and we know it can be transmitted in certain ways from certain medical procedures, such as hormone treatment in the early '80s. We do not know it can be transmitted by blood but there's no proof that it cannot. And in December a case was reported where both a blood donor and the recipient of that blood developed variant CJD. These two events may not be related but as a special precautionary measure we have decided that to ask people who have received blood since 1980 not to donate blood at the moment. This does not mean that such people are at risk of getting CJD …
PORTER
Just a precautionary measure.
HARRISON
… because it's so rare. But it is just a precautionary measure.
PORTER
Well if you want to find out if you can give blood, and how to go about it call the Radio 4 Actionline on 0800 044 044 or visit bbc.co.uk/radio4 and click on science.
Now, another way of easing pressure on the National Blood Service is to try and reduce demand from patients undergoing planned surgery. Andy Emery's wife was told she might need a transfusion to replace blood lost during an up and coming hip operation, so she decided to see if she could donate some of her own blood in the weeks leading up to the surgery, so the hospital could store it and give it back to her if required, but they weren't keen.
EMERY
Being comparatively young she had the newer version of the hip replacement, which is a resurfacing, it doesn't involve taking away a large amount of the bone which the conventional operation does. I think there may be a higher chance of blood loss because they have to make a larger incision than with the conventional operation. She did ask for advice as to whether she would lose blood, she was told that almost like a 50/50 chance that she would or wouldn't need a blood transfusion I think.
MACNAIR
Given this high likelihood that she would need blood after her operation, Andy's wife wanted to look at alternatives to receiving someone else's blood. Working in the health service she knew that there were other options. These included banking some of your own blood before an operation, which can then be used later in a procedure called pre-deposit auto-transfusion. She hoped that this would help to avoid the risk of complications from donor blood.
Dr Daffyd Thomas, a consultant anaesthetist working in Intensive Care for Swansea NHS Trust, explains how infection is a well known risk.
THOMAS
There have always been infective agents in the blood, historically it was things like syphilis and possibly tropical diseases such as malaria. But it was the HIV issue in the '80s that really brought it to the fore, that you could in fact transmit various infections via blood transfusion. And following on from that there's been hepatitis C and more recently variant CJD.
MACNAIR
Donor blood is carefully screened now and the risk of infection with HIV, for example is so low as to be negligible - about 1 in 10 million, although rare prion diseases such as variant CJD remain an issue. But there are other risks from donor blood, such as its effects on the immune system.
THOMAS
Blood transfusion is a bit like a liquid tissue transplant, it often causes an immune reaction and it's been documented for, probably, the last 30 odd years that people receiving allergenaic - that's donor blood - around the time of their operation are at an increased risk of perioperative infection. So there are distinct advantages to try and avoid that.
MACNAIR
Andy's wife did her best to avoid a donor transfusion, but despite discussing the options with all the right people weeks beforehand, she wasn't able to arrange to store some of her own blood. The main reason she was given was that doing so would hold up surgery.
EMERY
They said to her that if she was insistent on having it then there could be a strong chance that the operation would be delayed. Well at this time she was in an awful lot of pain and she opted to go ahead with the operation, possibly thinking that there was also a fairly good chance that she wouldn't need a transfusion. But unfortunately she did need a transfusion, I think it was given to her a day or two after the actual operation.
MACNAIR
In their frustration Andy contacted the ³ÉÈËÂÛ̳ helpline to try to find out why more wasn't being done to reduce the need for donor blood.
EMERY
What I really came onto the programme or what I'm interested in is an explanation from the experts as to why when patients need routine surgery where loss of blood can be anticipated why it's not possible for them to donate their own blood pre-operation. As a non-medical expert it would seem to be a fairly minor piece of administration to take blood, freeze it and reuse it for the operation.
MACNAIR
According to Dr Thomas there are several reasons why pre-deposit auto-transfusion may not be offered.
THOMAS
It's quite an elaborate system to get patients who may not be as fit as walking donors, if you understand me, to come in and donate their own blood prior to the operation and you need to take perhaps three or four units in the preceding month because the shelf-life of blood is about 35 days and you can't collect it too early, unless you're going to freeze it, and so there are logistical difficulties in collecting that blood.
MACNAIR
Many people simply aren't fit enough to give up several units of their own blood in a few weeks, and others are on medication such as beta-blockers which might make the collection of blood hazardous. Even if they are fit, donating several units of blood is a large drain on the body's resources.
THOMAS
Despite what you may try and do which is boost their iron stores and promote better manufacture of red cells in the patient they will inevitably present for surgery slightly more anaemic than they would have been otherwise and they may then end up at an increased risk of requiring a transfusion.
MACNAIR
Studies have shown that Pre-deposit auto-transfusion is not very cost effective, and so for all these reasons is not widely available in the UK. More importantly there are better ways to avoid using donor blood.
THOMAS
The other alternatives are using devices that salvage the blood during the operation - that's called salvage auto-transfusion. Or you can actually dilute your blood and take some units off, act as an immediate donor, in the anaesthetic room before the operation and that's called normo-volemic haemodilution. So there are other options. Likewise if you have a wound drain following an operation you can then recycle that blood and give it back to the patient. Now all of these are probably a more cost-effective option because you only collect blood if you're actually bleeding.
MACNAIR
Although it may sound a bit gruesome, collecting the blood that is spilled and then recycling it is easy, and the best option for the patient.
THOMAS
It is collected in a sterile jar via a suction apparatus used at the operation - surgeons often use suction to remove blood from the surgical field. So we're just collecting that blood in a sterile manner. It is then washed in normal saline - just a saline wash - and resuspended as red cells in saline and given back to the patient. In fact it works better than the donor blood because it's nice and pink, it's only just left the body, and has distinct advantages over stored blood - it carries oxygen straightaway, which is obviously what we're trying to do in giving a blood transfusion is to boost people's oxygen delivery to the tissues.
MACNAIR
Cell salvage is now one of the main strategies recommended by the blood service. But it is too late for Mrs Emery.
EMERY
She's now unable to give blood and this was a thing that she'd always enjoyed doing, she felt she was doing good for the community and coupled to this she's got the problem in the back of her mind that she may have contracted one of these awful blood borne diseases such as CJD.
PORTER
Tricia MacNair talking to Andy Emery about his wife's attempts to avoid blood transfusion.
We should just say that the risk of catching a transmitted infection is infinitesimally small isn't it.
HARRISON
It's extremely small indeed, you're much likely to be struck by lightening or something like that.
PORTER
How much blood can someone use before they need - lose before they need a transfusion?
HARRISON
Well we now realise that a healthy - a person who's otherwise healthy, other than their hip for which they were having the operation, for example - can lose almost half their red cells before they really need a transfusion.
PORTER
And that's relatively recent because we used to transfuse much earlier didn't we.
HARRISON
Yes, we used to top people up - that was the expression. But now we're very cautious about giving blood and we really do not give blood unless the person's life or health is in danger. We would leave them a bit anaemic after operation and then they can take some iron and their own system will gradually make up the blood loss.
PORTER
Let's move on to the most common abnormality of blood of all which is anaemia, you've just mentioned. What is wrong with someone who is anaemic?
HARRISON
It means they have lost red cells and therefore they don't have enough haemoglobin to carry oxygen round the body at optimum rate.
PORTER
How would they know that they were anaemic?
HARRISON
Well they would feel tired and listless because their heart would have to be working extra hard to pump the blood round to get the oxygen to the tissues and they might be a bit short of oxygen to the tissues.
PORTER
And they look pale presumably?
HARRISON
And they would look pale yes.
PORTER
The most common type - iron deficiency anaemia - is particularly common in women isn't it.
HARRISON
Yes and particularly women of child bearing age because menstrual loss every month might be a bit excessive and they might not be eating enough iron in their diet to make up for the loss every month.
PORTER
So they're actually losing the iron in the menstrual loss?
HARRISON
Yes, yes.
PORTER
And that's difficult to make up in diet because it's quite difficult to absorb iron from our diet isn't it.
HARRISON
That's right, women have to take twice as much iron as a healthy man in order to keep up with the menstrual loss.
PORTER
Well iron deficiency may be common in women but in men it may be a sign of more sinister underlying problems. Dr Keith Patterson is a consultant haematologist at University College Hospitals, London.
PATTERSON
In men iron deficiency is rarer - well anaemia is rarer - and you often find that it's associated with some underlying disease.
PORTER
What sort of diseases?
PATTERSON
Well chronic bleeding particularly. Now some times you may find that the patient has a history of gastrectomy, they've had part of their stomach removed, which used to be a treatment for peptic ulceration. And if you've had part of your stomach removed you don't make the stomach acid which allows you to split iron from protein so that it can be absorbed. So that can be a cause. Bleeding from various sources from within the gastrointestinal tract. Peptic ulcer's not now as common as it used to be. Cancers of the stomach or colon are an important diagnosis and in a man who has a new diagnosis of iron deficiency anaemia one has to take a careful history, symptoms from the gastrointestinal tract because it is possible to diagnose and cure a cancer of the colon or of the stomach which might be bleeding, causing iron deficiency anaemia but has not yet worked through the stomach wall and therefore it can be cured by surgery and prevented from spreading.
PORTER
Assuming the iron deficiency's uncomplicated how do you we treat it?
PATTESON
Well it's simply a matter of taking tablets - pherosulphate is the most commonly used compound, two or three tablets a day in most patients will restore the haemoglobin level to normal in a few weeks. So the treatment is fairly simple and cheap. Unfortunately, iron tablets are associated with a fairly high incidence of gastrointestinal intolerance …
PORTER
Upset stomach.
PATTERSON
Upset stomach, constipation, sometimes diarrhoea. Usually you can simply reduce the dose and accept lower rate of response in the blood and get by these symptoms.
PORTER
And how long do you need to take the iron tablets for?
PATTERSON
Well we usually recommend to take the iron tablets until the haemoglobin has returned to normal and a good response would be a rise in the haemoglobin level of a gram a week. So a woman would normally have a haemoglobin over eleven and a half, if her haemoglobin was down to nine then a week's iron should make it up to ten, if she's having a good response. We do like to continue the iron for a further couple of months in order to give the woman some stores of iron to draw on because presumably if she's continuing to have periods iron loss will continue and therefore we need to give her a little reserve in a savings bank, as it were, to draw on.
PORTER
Jean, we highlighted men there with iron deficiency but presumably we should have a low threshold of suspicion with older women who've got iron deficiency as well?
HARRISON
Yes for the same sort of reasons. But I would like to say that iron deficiency in men is not always sinister and the commonest cause of bleeding from the gut, causing anaemia in men, is in fact piles.
PORTER
And not cancer.
HARRISON
And not cancer.
PORTER
I am afraid we must stop there. Dr Jean Harrison - thank you very much.
If you want anymore information on the topics discussed today then do call the Actionline on 0800 044 044 or for useful contacts and addresses and that includes details of how to become a blood donor visit bbc.co.uk/radio4 and click on science. Where you can also listen to the programme again and even print off a transcript.
Next week it's oral health - I'll be finding out why children have milk teeth, how the state of your gums can affect your odds of developing heart disease, and how to tell the difference between a troublesome mouth ulcer and a life threatening cancer.
<< Back to main page
|
ÌýPrint this page
