Bernard F. Feldman, DVM, PhD
Virginia-Maryland Regional College of Veterinary Medicine Virginia Polytechnic Institute and State University
Blacksburg, VA, USA
RATIONALE FOR THERAPY
Whole blood is a mixture of cellular constituents suspended in a liquid transport medium. The cells have different functions. Erythrocytes carry oxygen and participate in host defense by surface adsorption and absorption of many materials, phagocytes control bacteria, platelets are required for hemostasis, and lymphocytes mediate immunity. The liquid medium also contains an array of dissolved substances: albumin, globulins, coagulation proteins, metabolic intermediates, electrolytes, organic anions, and trace elements. Practical techniques for separation and concentration of some of the cellular constituents of whole blood are within the capabilities of all major veterinary blood donor centers. Modern transfusion therapy should be based upon use of components to treat specific defects with concentrates of the deficient blood constituent. There are a number of rationales for the preferential use of blood components. (Barnes, 1993)
Consideration of the Limited Resource
The most cogent argument supporting component therapy is that blood is a precious resource considering its therapeutic potential and the logistics and costs required in obtaining and delivering blood products. Separation into components permits a single donation to meet the individual needs of more than several patients. Blood donor screening eligibility criteria should be sufficient to obtain a safe donation.
Following hemorrhage, homeostatic mechanisms restore the various blood constituents at differing rates, depending on the capacity for synthesis, endogenous consumption, degradation, and distribution in various physiologic compartments. The half inactivation time of canine and feline red cells is in terms of months whereas the half-life of albumin is just three to four days. Surgical blood loss may require restoration of red cells. Albumin may not be required as it will be restored within several days. Another consideration is tolerance. Loss of fifty percent of red cell mass is well tolerated in a healthy individual whereas loss of fifty percent of blood volume can be fatal unless rapidly corrected.
Consideration of Adverse Effects
Other rationale for supporting the use of blood components include the myriad of possible adverse effects that can result from transfusion of unnecessary blood constituents. Any transfusion reaction means that the transfusion is not doing the intended job and, importantly, has burdened a patient already burdened by the physiologic state requiring transfusion. Sensitization to blood cells can result in refractory results in subsequent transfusions. Transfusion of multiple units of whole blood sequentially in order to achieve a certain hematocrit may also produce pulmonary edema due to volume overload.
Blood Donor Screening
All blood donors should be given thorough physical examinations at each donation and be annually screened hematologically, biochemically, and serologically. Donors should be healthy, receiving adequate nutrition, and be parasite free. All donors should be blood typed and be current on appropriate vaccinations. Female donors should not have had pups or kittens and preferably not be intact. In addition, all canine donors should be screened for brucellosis, heartworm microfilaria, ehrlichiosis, Rocky Mountain spotted fever, trypanosomiasis, and systemic mycoses. Feline donors should be house cats not allowed to roam. Cats should be screened for retroviruses, heartworm microfilaria, toxoplasmosis, and hemobartonellosis.
Blood Typing (see below)
The feline AB blood group system consists of three blood types: type A, type B, and type AB. All type B cats have strong alloantibodies against type red blood cells. Type A cats have weak but potent antiB alloantibodies in terms of the life expectancy of transfused type B cells. These alloantibodies are responsible for transfusion reactions and neonatal isoerythrolysis in cats and can be detected by crossmatch procedures. Feline patients receiving blood products should receive donor products of the same blood type as the patient and... have had crossmatch testing which indicates compatibility. Cats with the rare AB blood type should receive AB blood (often quite difficult to obtain) or type A blood which is compatible or only slightly incompatible in the minor crossmatch. There are no feline "universal" donors.
A simple "in-house" card test for feline red cell antigens A, B, and AB and canine DEA 1.1 has The dog has eight different blood types identified as dog erythrocyte antigens (DEA) 1.1, 1.2, 3, 4, 5, 6, 7, and 8. The use of DEA 1.1 and 1.2 positive blood products that are crossmatch incompatible may cause hemolysis. Controversy exists as to whether DEA 7 is an important determinant in canine transfusion reactions. Ideally canine blood negative for DEA 1.1, 1.2 and 7 should be used as it conforms with the concept of "universal" donor blood. In random source, first time canine transfusion of non-crossmatched or typed blood the transfusion reaction rate is approximately fifteen percent. Again, transfusion reaction indicates that the materials transfused are not effective and are causing a physiologic burden on an already burdened patient--reasons to blood type and crossmatch. Recently there has been suggestions that the only significant canine antigen is DEA 1.1. Donors blood products negative for DEA 1.1 that are crossmatch compatible have a much reduced chance of transfusion reaction. Recently, card tests to detect feline blood types A, B, and AB and canine blood type 1.1 have become available.a
Crossmatching reveals the presence of naturally occurring isoantibodies or antibodies generated in response to a previous incompatible transfusion. Crossmatching does not prevent sensitization of the patient to future transfusions. In fact, even though a specific blood donor is crossmatch compatible with the patient, if five or more days have elapsed since the first transfusion, another crossmatch must be performed if more blood products are to be administered and especially when the same donor blood products will be used.
Crossmatching is a simple technique that can be performed with standard laboratory equipment. A major, minor, and autocontrol crossmatch should be performed although the minor crossmatch is rarely used in dogs. The major crossmatch should always be compatible at room temperature and at 37 degrees Celsius (°C).
The following is a simple (nonpurist) major crossmatch protocol (donor red cells and patient serum or plasma):
1. Centrifuge EDTA or citrated DONOR blood at the LOWEST centrifugal rate possible on your centrifuge...for about 10 minutes.
2. Remove 0.2 mLs of packed and place in 4.8 mLs of normal (0.9%) saline. Mix. (There are now 5.0 mLs in the tube; this essentially replaces washing step.)
3. Place 0.1 mL of this mixture into three small test tubes.
4. Place 0.1 mL of PATIENT serum or plasma into each of the three tubes described above. Each tube will now have 0.1 mL of the donor red cell-saline mixture and 0.1 mL of patient serum or plasma, a total of 0.2 mLs each.
5. Incubate-for 15 minutes-one tube at 37 degrees C, one at room temperature (25 degreesC), and one at refrigerator temperature (4 degrees C).
6. Centrifuge briskly for one minute.
7. Examine the supernatant for any hemolysis. Any hemolysis indicates crossmatch incompatibility.
8. Examine the cell button. Flick or swish the test tube. The fluid in the tube should redden as red cells disperse. If the button is agglutinated or microagglutinated (examine a drop under low microscopic power), this indicates crossmatch incompatibility. To complete the minor crossmatch, use patient red cells & donor serum or plasma. To complete the autocontrol use patent red cells and patient plasma. In dogs the minor crossmatch is useful for a patient receiving multiple plasma product transfusions.
The Decision to Transfuse
All transfusion therapy can produce only transient improvement in the patient's condition. Unless the patient is able to produce the deficit component endogenously, more transfusions will be necessary. Furthermore, transfusions dampen the physiologic response to deficiency of a blood constituent. For example if a patient has a low red cell mass, tissue hypoxia results in increased erythropoietin production and the marrow responds with reticulocytosis. Red cell transfusion, in this patient, will result in diminished and delayed reticulocyte response. Several questions should be considered when considering transfusion.
1. Is blood transfusion really necessary?
2. What is the patient's particular clinical need?
3. Does the prospective benefit justify the risks of transfusion?
4. What blood component will effectively meet this special need at the lowest cost?
5. (After transfusion) Did the transfusion result in the anticipated benefit for the patient?
Bernard F. Feldman, MD, PhD, Virginia-Maryland Regional Chuo cha Veterinary Medicine, Virginia Polytechnic Institute na Chuo Kikuu cha Jimbo la Blacksburg, VA, USA, RATIONAL FOR THERAPY Damu nzima ni mchanganyiko wa viungo vya seli vilivyowekwa katika njia ya usafirishaji wa kioevu. Chembe hizo zina kazi tofauti-tofauti. Erythrocytes hubeba oksijeni na kushiriki katika ulinzi wa mwenyeji kwa adsorption ya uso na kunyonya vifaa vingi, phagocytes kudhibiti bakteria, platelets zinahitajika kwa hemostasis, na lymphocytes kuwasiliana kinga. Mzunguko wa kioevu pia una safu ya vitu vilivyomwagika: albumin, globulins, protini za kuganda, vitu vya kati vya kimetaboliki, electrolytes, anions za kikaboni, na elementi za alama. Mbinu za kutenganisha na kukusanya baadhi ya vipengele vya seli za damu nzima ziko ndani ya uwezo wa vituo vyote vikubwa vya kutoa damu kwa wanyama. Matibabu ya kisasa ya uhamisho wa damu yanapaswa kutegemea matumizi ya vipengele vya kutibu kasoro maalum na misingi ya kiungo cha damu kinachopungukiwa. Kuna sababu kadhaa za kutumia vipengele vya damu kwa njia ya upendeleo. "Barnes, 1993: ""Kuchunguza rasilimali ndogo: hoja ya kuvutia zaidi inayounga mkono tiba ya sehemu ni kwamba damu ni rasilimali ya thamani kwa kuzingatia uwezo wake wa matibabu na vifaa na gharama zinazohitajika katika kupata na kutoa bidhaa za damu.""" Kutenganishwa katika vipengele inaruhusu mchango mmoja ili kukidhi mahitaji ya mtu binafsi ya wagonjwa zaidi ya kadhaa. Vigezo vya kufuzu kwa wafadhili wa damu vinapaswa kuwa vya kutosha kupata mchango salama. Baada ya kutokwa na damu, utaratibu wa homeostatic hurudisha vipengele mbalimbali vya damu kwa viwango tofauti, kulingana na uwezo wa synthesis, matumizi ya endogenous, uharibifu, na usambazaji katika compartments mbalimbali physiological. Wakati wa nusu ya inactivation ya canine na feline nyekundu seli ni katika suala la miezi wakati nusu ya maisha ya albumin ni tu siku tatu hadi nne. Kupoteza damu kwa upasuaji kwaweza kuhitaji kurudishwa kwa chembe nyekundu za damu. Albumini inaweza kutohitajika kama itakuwa kurejeshwa ndani ya siku kadhaa. Jambo jingine la kuzingatia ni uvumilivu. Kupoteza asilimia 50 ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu ya damu. "Kama matokeo ya utafiti, ""Mafaa ya damu"" ni moja ya sababu za msingi za matumizi ya vipengele vya damu, pamoja na athari nyingi zinazoweza kutokea kutokana na uingizaji wa vipengele vya damu visivyo muhimu." "Mtazamo wowote wa damu unaonyesha kwamba damu haifanyi kazi inayokusudiwa na, muhimu zaidi, imemzidisha mgonjwa ambaye tayari amezidiwa na hali ya kisaikolojia inayohitaji damu.""" Uwezo wa kuathiriwa na chembe za damu waweza kusababisha matokeo yasiyofaa katika utiaji- damu uliofuata. Mtiririko wa vitengo vingi vya damu nzima kwa mfululizo ili kufikia hematocrit fulani pia inaweza kuzalisha uvimbe wa mapafu kutokana na mzigo wa ziada wa kiasi. Utafiti wa Mtoaji Damu: Wafadhili wote wa damu wanapaswa kupimwa kwa uangalifu kila mara wanapotoa damu na kuchunguzwa kila mwaka kwa hematolojia, biokemia, na serolojia. Watoaji wanapaswa kuwa na afya nzuri, kupata lishe ya kutosha, na kuwa huru kutoka kwa vimelea. Wafadhili wote wanapaswa kuwa na aina ya damu na kuwa na chanjo zinazofaa. Wafadhili wa kike hawapaswi kuwa na watoto au paka na ni bora wasiwe na afya. Kwa kuongezea, wafadhili wote wa mbwa wanapaswa kuchunguzwa kwa brucellosis, microfilaria ya mdudu wa moyo, ehrlichiosis, homa ya Rocky Mountain, trypanosomiasis, na mycoses ya mfumo. Watoaji wa paka wanapaswa kuwa paka wa nyumbani wasioweza kutangatanga. Paka wanapaswa kuchunguzwa kwa ajili ya retroviruses, heartworm microfilaria, toxoplasmosis, na hemobartonellosis. Aina ya damu ya paka (katika jamii ya paka) ni aina tatu za damu: aina A, aina B, na aina AB. Paka wote wa aina ya B wana kingamwili zenye nguvu dhidi ya chembe nyekundu za damu za aina ya B. Aina ya paka A wana antiB alloantibodies dhaifu lakini yenye nguvu katika suala la matarajio ya maisha ya seli za aina ya B zilizopitishwa. Alloantibodies hizi ni wajibu kwa ajili ya athari za uhamisho na neonatal isoerythrolysis katika paka na inaweza kugunduliwa na taratibu crossmatch. Kwa wale wanaopokea bidhaa za damu, lazima wapate bidhaa za mchangiaji wa aina moja ya damu na mgonjwa na... wamekuwa na upimaji wa msalaba ambao unaonyesha utangamano. Paka wenye aina ya damu ya AB ya nadra wanapaswa kupokea damu ya AB (mara nyingi ni ngumu kupata) au damu ya aina ya A ambayo ni sambamba au tu kidogo isiyo sambamba katika mchanganyiko mdogo. Hakuna watoaji "wa ulimwengu wote mzima" wa paka. Kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano. Kwa sababu ya matumizi ya DEA-positive, DEA-positive na DEA-positive, bidhaa za damu ambazo hazipatikani na crossmatch zinaweza kusababisha hemolysis. Kuna utata kuhusu kama DEA-7 ni sababu muhimu katika athari za uingizaji damu wa mbwa. Damu ya mbwa ya DEA-negative 1.1, 1.2, na 7 inapaswa kutumika kwa sababu inalingana na dhana ya damu ya mtoaji wa "ulimwengu". Katika chanzo cha nasibu, mara ya kwanza canine uhamisho wa damu isiyo ya msalaba au aina ya damu kiwango cha athari ya uhamisho ni takriban asilimia kumi na tano. Kwa mara nyingine tena, athari ya damu inaonyesha kwamba vifaa vilivyopitishwa si vyenye ufanisi na vinasababisha mzigo wa kisaikolojia kwa mgonjwa aliye na mzigo tayari - sababu za kikundi cha damu na ulinganifu wa damu. Kwa mfano, kuna uwezekano kwamba antigen ya mbwa pekee inayojulikana ni DEA-1.1. Kwa wale ambao wamepewa damu ya DEA-negative, na ambao wana uwezo wa kupata damu ya DEA-negative, uwezekano wa kupata damu ya DEA-negative ni mdogo sana. Kwa mfano, katika majaribio ya damu ya paka, aina ya damu ya A, B, na AB, na aina ya damu ya mbwa, aina ya damu ya A, B, na B, kuna uwezekano wa kugundua kwamba kuna aina ya damu ya aina ya A, B, na B. Kupatanisha damu kwa njia tofauti-tofauti hakuzuii mgonjwa asijihisi kuwa na uwezo wa kupokea damu wakati ujao. Kwa kweli, hata ingawa mchangiaji wa damu hususa ni cross-match sambamba na mgonjwa, ikiwa siku tano au zaidi zimepita tangu uingizaji wa kwanza, cross-match nyingine lazima ifanywe ikiwa bidhaa zaidi za damu zinapaswa kutolewa na hasa wakati bidhaa za damu za mchangiaji zilitumiwa. Crossmatching ni mbinu rahisi ambayo inaweza kufanyika na vifaa vya kawaida vya maabara. Mtihani mkubwa, mdogo, na wa kudhibiti moja kwa moja unapaswa kufanywa ingawa mtihani mdogo hutumiwa mara chache kwa mbwa. Kwa hivyo, kwa sababu ya hali ya hewa ya kawaida, crossmatch ya msingi inapaswa kuwa sawa wakati wa joto la chumba na 37 ° C. Kwa mfano, kwa mfano, mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani wa mtihani. Centrifuge EDTA au citrate DONOR damu kwa kiwango cha chini cha centrifugal iwezekanavyo kwenye centrifuge yako kwa dakika kumi. 2. Uwezekano wa kupata Kuondoa 0.2 ml ya mchanganyiko na kuweka katika 4.8 ml ya kawaida (0.9%) saline. Mchanganyiko. (Sasa kuna 5.0 mLs katika bomba; hii kimsingi inachukua nafasi ya hatua ya kuosha.) 3. Uwe na mtazamo wa kweli Weka m2 ya mchanganyiko huu katika mirija mitatu ya majaribio. 4. Uwe na uhakika Weka m2 ya seramu ya mgonjwa katika kila moja ya mirija mitatu iliyoelezwa hapo juu. Kila chombo cha mtihani kina 0.1 ml ya mchanganyiko wa damu ya damu ya mtoaji na 0.1 ml ya seramu ya mgonjwa, jumla ya 0.2 ml kila moja. 5. Uwe na mtazamo mzuri. Kwa dakika 15 chombo kimoja cha kuhifadhi kinapaswa kuwa na joto la 37 ° C, kingine cha kuhifadhi katika chumba cha joto (25 ° C), na kingine cha kuhifadhi katika friji (4 ° C). 6. Uwe na uhakika Centrifuge kwa kasi kwa dakika moja. 7. Uwe na mtazamo gani? Chunguza supernatant kwa ajili ya hemolysis yoyote. Upasuaji wowote wa damu huonyesha kutoelewana kwa msalaba. 8. Uwe na mtazamo gani? Chunguza kifungo cha simu. Piga au piga-piga bomba la majaribio. Kioevu kilicho katika bomba hilo kinapaswa kuwa nyekundu chenye mionzi ya damu. Kama kifungo ni agglutinated au microagglutinated (chunguza tone chini ya nguvu ya chini microscopic), hii inaonyesha crossmatch kutoelewana. Kukamilisha crossmatch ndogo, kutumia mgonjwa nyekundu seli & mchangiaji seramu au plasma. Kukamilisha autocontrol kutumia patent nyekundu seli na mgonjwa plasma. Katika mbwa crossmatch ndogo ni muhimu kwa mgonjwa kupokea transfusions nyingi ya bidhaa plasma. Uamuzi wa Kupatia Mshipa Matibabu yote ya kumimina damu yanaweza kuleta uboreshaji wa muda tu katika hali ya mgonjwa. Isipokuwa mgonjwa anaweza kutokeza sehemu hiyo isiyo na upungufu kwa njia ya ndani, damu zaidi itahitajiwa. Isitoshe, kutiwa damu mishipani huzuia mwili usipate sehemu fulani ya damu inayopungua. Kwa mfano, ikiwa mgonjwa ana kiasi kidogo cha chembe nyekundu, hypoxia ya tishu husababisha ongezeko la uzalishaji wa erythropoietin na marrow inajibu kwa reticulocytosis. Utoaji wa chembe nyekundu, katika mgonjwa huyu, utasababisha kupungua na kucheleweshwa kwa majibu ya reticulocyte. Maswali kadhaa yanapaswa kuzingatiwa tunapofikiria kumtia damu mishipani. 1. Uwe na mtazamo wa kweli Je, ni Lazima Kweli Kupatiwa Damu? 2. Uwezekano wa kupata Ni nini uhitaji maalum wa kliniki wa mgonjwa? 3. Uwe na mtazamo wa kweli Je, faida inayotarajiwa inastahili hatari za kutiwa damu mishipani? 4. Uwe na uhakika Ni sehemu gani ya damu itakayotosheleza uhitaji huo wa pekee kwa gharama ya chini zaidi? 5. Uwe na mtazamo mzuri. (Baada ya kutiwa damu) Je, mtiririko wa damu ulileta manufaa yaliyotarajiwa kwa mgonjwa?