Trans­fu­sions bring ex­perts’ blood to boil

Con­trary to their be­nign im­age, blood trans­fu­sions are overused and of­ten harm pa­tients, ex­pert say. Lyn­nette Hoff­man re­ports

The Weekend Australian - Travel - - Health -

REFUSE at your own risk: for years that’s the mes­sage doc­tors have re­layed to Je­ho­vah’s Wit­nesses and oth­ers who’ve de­clined blood trans­fu­sions. But trans­fu­sions are not the won­der pro­ce­dure of pop­u­lar, or even med­i­cal pro­fes­sion, imag­i­na­tion. Mount­ing ev­i­dence shows they sig­nif­i­cantly in­crease the risk of post­op­er­a­tive com­pli­ca­tions — in­clud­ing in­fec­tions, kid­ney fail­ure, lung in­jury and death.

Yet in­stead of be­ing saved as a last re­sort, they are still be­ing per­formed when other safer op­tions could be used in­stead. In fact, more than 25 per cent of blood trans­fu­sions cur­rently per­formed are un­nec­es­sary, ac­cord­ing to a visit­ing US ex­pert who spoke at the an­nual sci­en­tific meet­ing of the Aus­tralian and New Zealand Col­lege of Anaes­thetists (ANZCA) two weeks ago.

In­ter­na­tion­ally renowned emer­gency medicine and anaesthi­ol­ogy pro­fes­sor Bruce Spiess told the con­fer­ence that while blood trans­fu­sions have long been ‘‘ be­lieved to be help­ful and a pil­lar of mod­ern medicine’’, there was now rel­a­tively lit­tle ev­i­dence to sup­port such claims.

‘‘ Drug op­tions are care­fully tested and reg­u­lated through prospec­tive, ran­domised dou­ble-blind test­ing, but blood trans­fu­sion stands apart,’’ Spiess says. ‘‘ It has never been safety or ef­fi­cacy tested.’’

It’s a point that has been echoed by sev­eral Aus­tralian ex­perts, in­clud­ing anaes­the­sists as­so­ci­ate pro­fes­sor Larry McNi­col and doc­tor Peter McCall at Austin Health in Melbourne.

‘‘ From the point of view of the risk of trans­mit­ting in­fec­tions, blood trans­fu­sions are safer than they have ever been,’’ McCall says.

‘‘ How­ever, there is an ever-in­creas­ing body of re­search about ad­verse out­comes in as­so­ci­a­tion with them. Still there is a ten­dency to think that blood trans­fu­sions are mys­ti­cal and life­sav­ing, and it is bet­ter to give them than to with­hold them.’’

The rea­sons not to make blood trans­fu­sion rou­tine are be­com­ing in­creas­ingly ap­par­ent: a per­son who has had a blood trans­fu­sion af­ter surgery has up to four times the risk of wound in­fec­tions. Peo­ple who have blood trans­fu­sions dur­ing can­cer surgery face up to twice the risk of the can­cer re­cur­ring.

In his con­fer­ence pre­sen­ta­tion, Spiess dis­cussed Swedish re­search on car­diac pa- tients that com­pared Je­ho­vah’s Wit­nesses who re­fused blood trans­fu­sions to pa­tients with sim­i­lar dis­ease pro­gres­sion dur­ing open­heart surgery. The re­search found those who re­fused trans­fu­sions had no­tice­ably bet­ter sur­vival rates.

There are a few ma­jor rea­sons com­pli­ca­tions arise fol­low­ing trans­fu­sion. For one thing, im­mune re­sponse is im­paired as the body re­sponds to the blood as a for­eign body, much in the same way it re­sponds to a trans­plant, ex­perts say. The prop­er­ties of red blood cells also be­come altered when blood is stored, re­duc­ing their abil­ity to dis­trib­ute oxy­gen through the body.

Yet at least 25 per cent of trans­fu­sions that are done could be avoided, Spiess says.

A 2005-2006 au­dit of the use of fresh frozen plasma in hos­pi­tals in Tas­ma­nia and Vic­to­ria found that one-third of the trans­fu­sions per­formed were in­ap­pro­pri­ate un­der un­der­guide­lines is­sued by the Na­tional Health and Med­i­cal Re­search Coun­cil, says as­so­ci­ate pro­fes­sor Larry McNi­col, who also chairs the Bet­ter Safer Trans­fu­sion pro­gram run by the Vic­to­rian Gov­ern­ment.

‘‘ Es­sen­tially th­ese pa­tients re­ally per­haps didn’t need it and there might not have been ther­a­peu­tic ben­e­fits,’’ McNi­col says.

But there are still cir­cum­stances when blood trans­fu­sion is nec­es­sary, and the pa­tient would prob­a­bly die if they did not re­ceive one, says Univer­sity of Syd­ney pro­fes­sor James Is­bis­ter, a con­sul­tant on haemo­tol­ogy and blood trans­fu­sion who chairs the Red Cross ad­vi­sory board.

Is­bis­ter says blood trans­fu­sion can be vi­tal for pa­tients un­der­go­ing ma­jor surgery af­ter ex­pe­ri­enc­ing ma­jor trauma or shock when there is ma­jor bleed­ing that is dif­fi­cult to con­trol quickly. It can also be in­stru­men­tal in man­ag­ing he­mo­philia, where blood does not clot, as well as acute hem­or­rhages.

‘‘ A lot of ma­jor surgery would never have de­vel­oped with­out the pos­si­bil­ity for blood trans­fu­sion ei­ther — for in­stance, open heart surgery,’’ Is­bis­ter says.

But many of the cases in the Bet­ter Safer Trans­fu­sion au­dit in­volved trans­fu­sions that could have been avoided. For ex­am­ple, it was once thought that blood trans­fu­sions should be per­formed any time a pa­tient’s he­mo­glo­bin level dipped be­low 10 grams of he­mo­glo­bin per decil­itre of blood — but now guide­lines in vary­ing coun­tries put that be­tween 6 and 8g.

‘‘ It used to be that 10g was the ac­cept­able min­i­mum, but now we know that pa­tients are at no detri­ment by a run­ning a lower count and we can avoid th­ese ad­di­tional risks,’’ McCall says. ‘‘ When the blood count is lower, the heart is able to beat more strongly — so it can ac­tu­ally pump more ef­fi­ciently to dis­trib­ute the blood bet­ter.’’

The au­dit also un­cov­ered a ten­dency for some doc­tors to use trans­fu­sions as a pre­cau­tion in pa­tients who were at risk of bleed­ing, but not yet bleed­ing — for ex­am­ple, they might have had ab­nor­mal test re­sults. In those cases the guide­lines rec­om­mend doc­tors wait un­til bleed­ing starts.

Other stud­ies have also shown that the like­li­hood of re­ceiv­ing a trans­fu­sion dur­ing elec­tive or­thopaedic surgery or car­diac surgery can vary enor­mously be­tween hos­pi­tals, de­spite there be­ing lit­tle dif­fer­ence be­tween the pa­tients, Is­bis­ter says. ‘‘ There’s huge vari­a­tion be­tween hos­pi­tals and sur­geons de­pend­ing on where you have your op­er­a­tion — in one hospi­tal you can have an 80 per cent chance of be­ing trans­fused, and in an­other hospi­tal 10 per cent chance.’’

‘‘ Most pa­tients un­der­go­ing hip and knee surgery should only have a 10 to 20 per cent chance of need­ing a trans­fu­sion — but there’s ev­i­dence it can be much higher.’’

There are a num­ber of ways to avoid trans­fu­sions, in­clud­ing drugs that min­imise blood loss and oth­ers that stop clots from be­ing dis­solved, as well as anes­thetic and sur­gi­cal tech­niques to min­imise blood loss.

‘‘ You don’t al­ways have to bring a per­son’s blood pres­sure up to nor­mal — you can keep it low and that min­imises bleed­ing,’’ he says.

In surgery where there’s a risk of ma­jor blood loss, doc­tors fre­quently use a tech­nique called ‘‘ red cells sal­vage’’, which al­lows them to re­use the pa­tient’s own blood rather than trans­fus­ing some­one else’s. The pa­tient’s blood is col­lected in a ma­chine where it is then washed in a saline so­lu­tion be­fore be­ing given back to the pa­tient.

But the bat­tle to re­duce un­nec­es­sary trans­fu­sions of­ten be­gins be­fore surgery.

‘‘ One of the ways to min­imise trans­fu­sions is to pre­pare pa­tients bet­ter be­fore surgery — for ex­am­ple you can give them sup­ple­ments to get their blood count up be­fore surgery,’’ McCall says.

To that end a 2005 South Aus­tralian au­dit found that 18 per cent of peo­ple who had been on wait­ing lists for elec­tive surgery had ane­mia, which in­creases the chances of need­ing a trans­fu­sion. If the ane­mia had been bet­ter man­aged be­fore surgery some of those pa­tients could have avoided blood trans­fu­sions, ac­cord­ing to Kathryn Robin­son, med­i­cal ad­viser of South Aus­tralia’s Blood­Safe.

But for all the bad news, ex­perts say that change is on the hori­zon. Var­i­ous states are de­vel­op­ing ini­tia­tives to help de­crease un­nec­es­sary trans­fu­sions, and at a con­fer­ence of fed­eral and state health min­is­ters in March the fed­eral Gov­ern­ment said it would fund two ini­tia­tives ex­pected to im­prove the safety of the blood sup­ply and im­prove out­comes for peo­ple who do ul­ti­mately need trans­fu­sions.

One of those ini­tia­tives is the uni­ver­sal test­ing of platelets, which carry par­tic­u­larly high risks of com­pli­ca­tions. Un­like other blood prod­ucts, platelets can’t be re­frig­er­ated, so they are sus­cep­ti­ble to con­tam­i­na­tion by bac­te­ria. In­ter­na­tional guide­lines rec­om­mend all platelets be uni­ver­sally tested for the bac­te­ria, but cur­rently only about 5 per cent of the sup­ply is tested, McNi­col says.

At the same meet­ing the gov­ern­ment an­nounced that by 2010 all blood will be pro­cessed to re­move white blood cells, known as leuko-re­duced blood, which has been shown to dra­mat­i­cally re­duce com­pli­ca­tions and is al­ready in wide­spread use in Canada, New Zealand, West­ern Europe and else­where.

‘‘ There are three ran­domised con­trolled stud­ies in heart surgery, where pa­tients who were deemed ap­pro­pri­ate to be trans­fused got ei­ther leuko-re­duced blood or blood with white cells present,’’ Spiess says.

‘‘ The death rate in those with leuko­re­duced blood was roughly half that in those with blood with white cells,’’ Speiss says. ‘‘ In the pa­tients that got no blood, there were no deaths at all.’’

Pic­ture: Chris Crerar

Stuff of life: Peter McCall mon­i­tors blood dur­ing surgery at Melbourne’s Austin Hospi­tal

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