PO Administration 2 Out-patient regimen. 2 Women of childbearing potential must have negative pregnancy test within 24h before starting thalidomide, every 2 \200\2234 weeks while on tha lidomide and 4 weeks after last dose. 2 Add allopurinol 300mg od PO (100mg if significant renal impairment) for first cycle. 2 Antiemetic therapy for mildly emetogenic regimens. 2 Commence H2 antagonist or PPI. 2 Con sider regular laxative. 2 Do not give cyclophosphamide if serum creatinine >300 mol/L afte r rehydration. 2 Omit cyclophosphamide for 3 weeks if neutrophils <1.0 109/L or platelets <100 109/L . Reintroduce at 300mg or 400mg per dose. 2 Consider G-CSF if treatment delays are prolonged or frequent 2 Omit thalidomide for one c ycle if grade 3/4 constipation, neuropathy, fatigue, sedation, rash, tremor or oedema; rein troduce at 50mg/day. 628 2 Treat with full dose warfarin or LMW heparin if thromboembolic event. Stop thalidomide and restart at 50mg/day escalating on the sub- sequent cycle to 100 mg/day. 2 Repeat for 4 \200\2236 cycles 15-protocols.qxd 10.12.2003 04.32 PM Page 629 Protocols and procedures 629 15-protocols.qxd 10.12.2003 04.32 PM Page 630 This page intentionally left blank 630 16-haem Ix.qxd 10.12.2003 04.33 PM Page 631 Hematological investigations 16 Full blood count 632 Blood movie 632 Plasma viscosity 632 ESR 632 Haematinic assays 633 Hemoglobin electrophor esis 633 Hapt oglobin 633 Schumm \200\231s test 633 Kleihauer test 633 Reticulocytes 634 Urinary haemosiderin 635 Ham \200\231s test 636 Immunophenotyping 636 Cytogenetics 638 HLA typing 640 16-haem Ix.qxd 10.12.2003 04.33 PM Page 632 Full blood count Rapid analysis by the latest generation automated blood counters using either forward angle light scatter or impedance analysis provides enumer- ation of leucocytes, erythrocytes and platelets and quantification of hemoglobin, MCV plus derived values for haematocrit, MCH a nd MCHC, red cell distribution width (a measure of cell size scatter), mean platelet volume and platelet distribution width and a 5 parameter differential leu- cocyte count. The coun ter also flags samples which require direct mor- phological assessment by examination of a blood movie. Sample: peripheral blood EDTA; the sample should be analyzed in the laboratory within 4h. Blood movie Morphological assessment of red cells, leucocytes and platelets should be performed by an e xperienced individual of all samples in which the FBC has revealed any result significantly outside the normal range, samples in which a flag has been indicated by the automated coun ter and if clinically indicated. A manual differential leucocyte count may be performed and may differ from that produced by the automated counter most notably in patients with hemat ological disease affecting the leucocytes. Sample: peripheral blood EDTA; the sample should be analyzed in the laboratory within 4h. M ay be made directly from drop of blood or EDTA sample, air-dried and fixed. Plasma viscosity This test is a sensitive but non-specific index of plasma protein changes which result from inflammation or tissue damage. The plasma viscosity is unchanged by haematocrit variations and delay in analysis up to 24h and is therefore more reliable than the ESR. It is not aff ected by sex but is affected by age, exercise and pregnancy. 632 Sample: peripheral blood EDTA; the sample should be analyzed in the laboratory within 24h. ESR This test is a sensitive but non-specific index of plasma protein changes which result from inflammation or tissue damage. The ESR is affected by haematocrit variations, red cell abn ormalities (e.g. poikilocytosis, sickle cells) and delay in analysis and is therefore less reliable than measurement of the plasma viscosity. The ESR is affected by age, sex, menstru al cycle, pregnancy and drugs (e.g. OCP, steroids). Sample: peripheral blood EDTA; the sample should be analyzed in the laboratory within 4h. 16-haem Ix.qxd 10.12.2003 04.33 PM Page 633 Hematological investigations Haematinic assays Measurement of the serum B12 and red cell folate are necessary in the investigation of macr ocytic anemia, and serum ferritin in the investigation of microcytic anemia in order to ass ess body stores of the relevant haematinic(s). Serum folate levels are an unreliable measur ement of body stores of folate. The serum ferritin may be elevated as an acute phase protei n in patients with underlying neoplasia or inflammatory disease (e.g. rheumatoid arthritis) and may give an erroneously normal level in an iron deficient patient. Sample: clotted blood sample and peripheral blood EDTA. Hemoglobin electrophoresis This test is performed in the diagnosis of abnormal hemoglobin produc- tion (haemoglobinopa thies or thalassaemia). It is usually performed on cellulose acetate at alkaline pH (8.9) b ut may be performed on citrate agar gel at acid pH (6.0) to detect certain haemoglobins mor e clearly. Hemoglobin electrophoresis has been largely replaced by HPLC analysis. Sample: peripheral blood EDTA. Haptoglobin The serum haptoglobin should be measured in patients with suspected intravascular haemolysi s and is frequently reduced in patients with extravascular haemolysis. It should generally be accompanied by estima- tion of the serum methaemalbumin, free plasma hemoglobin and urin ary haemosiderin. Sample: clotted blood. 633 Schumm \200\231s test This spectrophotometric test for methaemalbumin (which has a distinc- tive absorption band at 558nm) should be measured in patients with sus- pected intravascular haemolysis and may be abnormal in patients with significant extravascular (generally splenic) haemolysis. It s hould generally be accompanied by estimation of the serum haptoglobin level, free plasma he moglobin and urinary haemosiderin. Sample: heparinised blood or clotted blood. Kleihauer test The Kleihauer test which exploits the resistance of fetal red cells to acid elution should be performed on all Rh(D) negative women who deliver a 16-haem Ix.qxd 10.12.2003 04.33 PM Page 634 Rh(D) positive infant. Fetal cells appear as darkly staining cells against a background of ghosts. An estimate of the required dose of anti-D can be made from the number of fetal cel ls in a low power field. Sample: maternal peripheral blood EDTA. Reticulocytes Definition 2 Immature RBCs formed in marrow and found in normal peripheral blood. 2 Represent an intermediate maturation stage in marrow between the nucleated red cell and the mature red cell. 2 No nucleus but retain some nucleic acid. Detection and measurement 2 Demonstrated by staining with supravital dye for the nucleic ac id. 2 Appear on blood movie as larger than mature RBCs with fine lacy blue staining strands or dots. 2 Some modern automated blood counters using laser technology can measure levels of reticulocytes directly. 2 Usually expressed as a % of total red cells e.g. 5%, though absolute numbers can be derived from this and total red cell count. Causes of 4 reticulocyte counts Marrow stimulation due to 2 Bleeding. 2 Haemolysis. 2 Respo nse to oral Fe therapy. 2 Infection. 2 Inflammation. 2 Polycythaemia (any cause). 2 Myelopr oliferative disorders. 2 Marrow recovery following chemotherapy or radiotherapy. 2 Erythrop oietin administration. Causes of 5 reticulocyte counts Marrow infiltration due to 2 Leukemi a. 2 Myeloma. 2 Lymphoma. 2 Other malignancy. 634 Marrow underactivity (hypoplasia) due to 2 Fe, folate or B12 deficiency. Note: return of re ticulocytes is earliest sign of response to replacement therapy. 2 Immediately post-chemotherapy or radiotherapy. 2 Autoimmune disease especially rheumatoid arthritis. 2 Malnutrition. 2 Uraemia. 2 Drugs. 16-haem Ix.qxd 10.12.2003 04.33 PM Page 635 Hematological investigations 2 Aplastic anemia (see p122). 2 Red cell aplasia (see p126). Urinary haemosiderin Usage The most widely used and reliable test for detection of chronic intravas- cular haemo lysis. Principle Free Hb is released into the plasma during intravascular haemolysis. The hemoglob in binding proteins become saturated resulting in passage of haem-containing compounds into the urinary tract of which haemosiderin is the most readily detectable. Method 1. A clean catch sample of urine is obtained from the patient. 2. Sample is spun dow n in a cytocentrifuge to obtain a cytospin prepara- tion of urothelial cells. 3. Staining and rinsing with Perl \200\231s reagent (Prussian blue) is performed on the glass slides. 4. Examine under oil-immersion lens of microscope. 5. Haemosiderin stains as blue dots with in urothelial cells. 6. Ignore all excess stain, staining outside cells or in debris all of which are common. 7. True positive is only when clear detection within urothelial squames is seen. Cautions An iron-staining +ve control sample should be run alongside test case to ensure st ain has worked satisfactorily. Haemosiderinuria may not be detected for up to 72 hours afte r the initial onset of intravascular haemol- ysis so the test may miss haemolysis of very r ecent onset \200\223 repeat test in 3 \200\2237 days if \200\223ve. Conversely, haemoside rinuria may persist for some time after a haemolytic process has stopped. Repeat in 7 days should confirm. 635 Causes of haemosiderinuria Red cell enzymopathies e.g. G6PD and PK deficiency but only during haemolytic episodes Myco plasma pneumonia with anti-I cold haemag- glutinin Sepsis Malaria Cold haemagglutinin disea se TTP/HUS Severe extravascular haemolysis (may cause intravascular haemolysis) Common causes 16-haem Ix.qxd 10.12.2003 04.33 PM Page 636 PNH Prosthetic heart valves Red cell incompatible transfusion reactions Unstable haemoglobi ns March haemoglobinuria Rarer causes Ham \200\231s test Usage Diagnostic test for paroxysmal nocturnal haemoglobinuria (PNH). Now replaced by immun ophenotyping methods. Principle 2 Abnormal sensitivity of RBCs from patients with PNH to the haemolytic action of complement. 2 Complement is activated by acidification of patient \200\231s serum to pH of 6.2 which in duces lysis of PNH red cells but not normal controls. Specificity: high \200\224similar reaction is produced only in the rare syndrome HEMPAS (a form of congenital dyserythropoietic anemia type II) which should be easily distinguished m orphologically. Sensitivity: concentration of magnesium in the serum. low \200\224as the reaction is crucially dependent on the It appears to be a technically difficult test in most laboratories. Patients with only a lo w % of PNH cells may be missed at an early stage of the disease. Markedly abnormal PNH cell s are usually picked up in 75% of patients. Less abnormal cells are detected in only 25% of patients. Alternative tests 2 Sucrose lysis \200\224an alternative method of complement activation i s by mixing serum with a low ionic strength solution such as sucrose. Sensitivity of this t est is high but specificity is low \200\224i.e. the opposite of the Ham \200\231s test. 2 Immunophenotypic detection of the deficiency of the PIG transmem- brane protein anchors i n PNH cells is becoming a more widely used alternative cf. PNH section p124. Monoclonal ant ibodies to CD59 or CD55 (DAF) are used in flow cytometric analysis. Major advantage is that test can be performed on neutrophils and platelets in PB which are more numerous than the PNH red cells. 636 Immunophenotyping Definition Identification of cell surface proteins by reactivity with monoclonal anti- bodi es of known specificity. Uses 2 Aids diagnosis and classification of hematological malignancy. 16-haem Ix.qxd 10.12.2003 04.33 PM Page 637 Hematological investigations 2 Assess cellular clonality. 2 Identify prognostic groups. 2 Monitor minimal residual disea se (MRD). Terminology and methodology Cell surface proteins are denoted according to their cluster di fferentiation (CD) number. These are allocated after international workshops define individ ual cell surface proteins by reactivity to monoclonal antibodies. Most cells will express m any such proteins and pattern of expression allows cellular characterisation. Monoclonal antibodies (MoAbs) are derived from single B-lymphocyte cell lines and have iden tical antigen binding domains known as idiotypes. It is easy to generate large quantities o f MoAbs for diagnostic use. 2 Cell populations from e.g. PB or BM samples are incubated with a panel of MoAbs e.g. anti-CD4, anti-CD34 which are directly or indi- rectly bound to a fluor escent marker antibody e.g. FITC. 2 Sample is passed through a fluorescence-activated cell sorter (FACS) machine. 2 FACS instruments assign cells to a graphical plot by virtue of cell size and granularity detected as forward and side light scatter by the laser. 2 Allows subpopulations of cells e .g. mononuclear cells in blood sample to be selected. 2 The reactivity of this cell subpopulation to the MoAb panel can then be determined by fluorescence for each MoAb. 2 A typical result for a CD4 T-lymphocyte population is shown: CD3, CD4 +ve; CD8, CD13, CD34, CD19 \200\223ve. Common diagnostic profiles CD13+, CD33+, CD 34, CD14 +ve. CD10 and TdT +ve. CD3, CD7, TdT +ve. CD10, CD19, surfa ce Ig +ve. CD5, CD19, CD23, weak surface Ig +ve. AML cALL T-ALL B-ALL CLL 637 Clonality assessment Particularly useful in determining whether there is a monoclonal B cel l or plasma cell population. (cid:2) Monoclonal B cells from e.g. NHL will have surface exp ression of (cid:2) or (cid:3) light chains but not both. (cid:2) Polyclonal B cells from e. g. patient with infectious mononucleosis will have both (cid:2) and (cid:3) expression. 16-haem Ix.qxd 10.12.2003 04.33 PM Page 638 Cytogenetics Acquired somatic chromosomal abnormalities are common in haemato- logical malignancies. Det ermination of patterns of cytogenetic abnormali- ties is known as karyotyping. Uses 2 Aid diagnosis and classification of hematological malignancy. 2 Assess clonality. 2 Identify prognostic groups. 2 Monitor minimal residual disease (MRD). 2 Determine engraftme nt and chimerism post-allogeneic transplant. Terminology 2 Normal somatic cell has 46 chromosomes; 22 pairs and XX or XY. 2 Numbered 1 \200\22322 in decreasing size order. 2 2 arms meet at centromere \200\224short arm denoted p, long arm denoted q. 2 Usually only visible during condensation at metaphase. 2 Stimulan ts and cell culture used \200\224colchicine to arrest cells in metaphase. 2 Stained to identify regions and bands e.g. p1, q3. Common abnormalities 2 Whole chromosome gain e.g. trisomy 8 (+8). 2 Whole chromosome loss e .g. monosomy 7 ( \200\2237). 2 Partial gain e.g. 9q+ or partial loss e.g. 5q \200\223 . 2 T ranslocation \200\224material repositioned to another chromosome; usually reciprocal e.g. t(9;22) \200\224the Philadelphia translocation. 2 Inversion \200\224part of chromosome runs in opposite direction e.g. inv(16) in M4Eo. 2 Many translocations involve point mutations known as oncogenes, e.g. BCR, ras, myc, bcl-2. Molecular cytogenetics 2 Molecular revolution is further refining the specific abnormalitie s in the genesis of hematological malignancies. 2 Techniques such as FISH (fluorescence in situ hybridisation) and PCR (polymerase chain re action) can detect tiny amounts of abnormal genes. 638 2 BCR-ABL probes are now used in diagnosis and monitoring of treat- ment response in CML. 2 IgH and T-cell receptor (TCR) genes are useful in determining clonality of suspected B and T cell tumors respectively. 2 Specific probes may be used in diagnosis and monitoring of subtypes of AML e.g. PML-RARA in AML M3. 16-haem Ix.qxd 10.12.2003 04.33 PM Page 639 Hematological investigations Common karyotypic abnormalities CML t(9;22) Philadelphia chromosome translocation creates BCR-ABL chimeric gene. AML t(8;21) t(15;17) inv(16) \200\2235, \200\2237 AML M2, involves AML-ETO genes \200\224has better prognosis. AML M3 involves PML-RARA genes \200\224has better prognosis. AML M4Eo \200\224has better prognosis. Complex abnormalities have poor prognosis. MDS \200\2237, +8, +11 5q \200\223 syndrome Associated with refractory anemia and better p rognosis. Poor prognosis. MPD 20q \200\223 and +8 Common associations. ALL t(9;22) t(4;11) Hyperdiploidy Hypodiploidy Philadelphia translocation, poor prognosis. Poor prognosis. Increase in total chromosome nu mber \200\224good prognosis. Decrease in total chromosome number \200\224bad prognosis. T-ALL t(1;14) Involves tal-1 oncogene. B-ALL and Burkitt \200\231s lymphoma t(8;14) Involves myc and IgH genes, poor prognosis. CLL +12, t(11;14) ATLL 14q11 639 NHL t(14;18) t(11;14) t(8;14) Follicular lymphoma, involves bcl-2 oncogene. Small cell lymphocytic lymphoma, involves bcl -1 oncogene. Burkitt \200\231s lymphoma, involves myc and IgH genes. 16-haem Ix.qxd 10.12.2003 04.33 PM Page 640 HLA typing HLA (human leucocyte antigen) system or MHC (major histocompatibility complex) is the name given to the highly polymorphic gene cluster region on chromosome 6 which codes for cell su rface proteins involved in immune recognition. The gene complex is subdivided into 2 regions Class 1 The A, B and C loci. These proteins are found on most nucleated cells and interact with CD8 + T lymphocytes. Comprising of DR, DP, DQ loci present only on B lymphocytes, monocytes, ma crophages and activated T lymphocytes. Interact with CD4+ T lymphocytes. Class 2 2 Class 1 and 2 genes are closely linked so one set of gene loci is usually inherited from each parent though there is a small amount of cross- over. 2 There is 1:4 chance of 2 siblings being HLA identical. 2 There are other histocompatibil ity loci apart from the HLA system but these appear less important generally except during HLA matched stem cell transplantation when even differences in these minor systems may caus e GvHD. Typing methods Class 1 and 2 antigens were originally defined by serological reactivity wit h maternal antisera containing pregnancy-induced HLA antibodies. Many problems with techniq ue and too insensitive to detect many polymor- phisms. Molecular techniques are increasingl y employed such as SSP. Molecular characterisation is detecting vast Class 2 polymorphism. Importance of HLA typing 2 Matching donor/recipient pairs for renal, cardiac and marrow ste m cell transplantation. 2 Degree of matching more critical for stem cell than solid organ trans- plants. 2 Sibling HLA matched stem cell transplantation is now treatment of choice for many malignancies. 2 Unrelated donor stem cell transplants are increasingly performed but outcome is poorer du e to HLA disparity. As molecular matching advances, improved accuracy will enable closer ma tches to be found and results should improve. 640 Functional tests of donor/recipient compatibility 2 MLC (mixed lymphocyte culture) \200\224 now rarely used. 2 CTLp (cytotoxic T lymphocyte precursor assays) \200\224determine the fre - quency of cytotoxic T lymphocytes in the donor directed against the recipient \200\224pro vides an assessment of GvHD occurring. HLA related transfusion issues 2 HLA on WBC and platelets may cause immunization in recipie nts of blood and platelet transfusions. 2 May cause refractoriness and/or febrile reactions to platelet transfu- sions. 16-haem Ix.qxd 10.12.2003 04.33 PM Page 641 Hematological investigations 2 WBC depletion of products by filtration prevents this. 2 Diagnosis of refractoriness conf irmed by detection of HLA or platelet specific antibodies in patient \200\231s serum. 2 Platelet transfusions matched to recipient HLA type may improve increments. 641 16-haem Ix.qxd 10.12.2003 04.33 PM Page 642 This page intentionally left blank 642 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 643 Blood transfusion 17 Using the blood transfusion laboratory 644 Maximum surgical blood ordering schedule (MSBOS) 646 Transfusion of red blood cells 648 Platelet transfusion 650 Fresh frozen plasma (FFP) 652 Cryo precipitate 654 Intravenous immunoglobulin 656 Autologous blood transfusion 658 Jehovah \200\231s Witnesses 660 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 644 Using the blood transfusion laboratory Requests for compatibility testing or blood grouping Transfusion samples and forms must be clearly identified and clerical details match exactly. The form and sample should be signed by the person taking the sample as vouching for the identity of the potential recipient. 2 3 points of identification are required: patient \200\231s full name, date of birth, hospital number. 2 Requests must be legible and clearly labeled with the name of the responsible clinician. 2 Indication for transfusion should be specified. 2 Indicate time for planned surgery. 2 Fo r major elective surgery where transfusion is usual with the proce- dure the laboratory should receive a G&S sample in advance (7 days) \200\224allows identifi cation of alloantibodies \200\223 the lab will arrange for appropriate blood units to be a vailable. 2 In genuine haemorrhagic emergencies ABO Rh (D) group compat- ible blood can be given without matching as the slight risk of this action far outweighs th e immediate risk of death from exsanguination. 2 Unmatched O Rh (D) \200\223ve blood should only be used in extreme emer- gency when the patient \200\231s blood group is unknown or, if known, blood of the same ABO and Rh type is unavailable. Emergency grouping can be conducted in 15 min; full laboratory compatibility testing can be completed in \211 1h. Can be 20 min in emergencies (sending G&S sample to laboratory may save valuable time). Hazards 2 Most serious is ABO mismatch \200\224almost invariably arises through cler- ical errors (at time of sampling) or when blood given to patient. 2 The blood transfusion l aboratory groups the blood sample received and assumes the sample has been correctly identi fied at the time of collection. Issue and administration of blood and blood products 1. Units of blood are labeled as being matched for an individual patient. 2. Before administering the patient/recipient identity must be checked (see 3 point identity above). 644 3. Label details are rechecked by trained nursing staff at the bedside immediately prior to the transfusion any discrepancies identified must be referred urgently to the blood bank a nd the clinician responsible for the patient \200\223 transfusion of that unit cannot proc eed until any ambiguity about identity has been resolved. 4. Unit of blood must be given within its expiry date. 5. Check for damage to the pack, dis colouration of the contained red cells, or evidence of haemolysis. 6. Administration of the unit must commence <30 min after leaving the blood bank and be com pleted within 4h of commencing infusion. 7. Administration of blood products must be record ed in the case notes. 8. The unique number of given RBCs or blood products should be entered in the notes. If given warm, ensure a safe approved warming procedure is used. 9. 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 645 Blood transfusion 645 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 646 Maximum surgical blood ordering schedule (MSBOS) A system of tailoring blood requirements to particular elective surgical procedures, includ ing \200\224importantly \200\224procedures which do not usually require blood cover. 2 The ABO group and Rh (D) type of the patient is determined on dupli- cate samples, and th e serum screened for significant RBC ( \200\230atypical \200\231) antibodies. If there are no antibodies, the serum is kept available ( \200\230saved \200\231) for a determined perio d (usually a week) \200\224this is the \200\230Group, Screen and Save \200\231 (G&S) proce dure. 2 If there are no atypical antibodies, and the planned surgery is likely to need peri-opera tive transfusion, the required number of red cell units are matched by routine tests, label ed and set aside in an accessible refrigerator. Storage conditions must meet certain standa rds (contin- uous recording of appropriate temperature, alarms, etc). 2 If more blood is required than anticipated, extra units must be readily available. If the need is urgent, suitable arrangements \200\224such as rapid matching (using the \200\230s aved \200\231 serum) and despatch procedures \200\224must enable the timely supply of blood . 2 If there are atypical antibodies, which may occur in up to 10% patients, their specificit y must be determined and, if clinically significant, suffi- cient (extra) red cell units la cking the relevant antigen provided and matched by detailed techniques. (These are often re ferred to as \200\230phe- notyped red cells \200\231.) 2 If there is no \200\230MSBOS \200\231 more units must be matched than are usually required for transfusion, in order to give rapid access if extra blood is needed. Matched \200\230bespoke \200\231 blood is therefore unavailable for other patients for the 2 \200 \2233 days set aside. 2 A good MSBOS gives better access to blood stocks and enables more efficient use, in parti cular of O Rh(D) \200\223ve blood. There is no good reason for regarding O Rh(D) \200\223 ve blood as a \200\230universal \200\231 donation type. It can be antigenic; and it is a p recious resource, being available from <8% of the population. 2 The surgical team must be confident in the system, and the blood bank staff committed to \200\230minimal barriers \200\231. The cross-match : transfusion ratio of a blood bank may well become lower than 2 (i.e. overall <2 units matched for every unit transfused) which i s an indication of effi- cient practices. It could even be nearer to 1 than to 2. 646 2 MSBOS schedules will vary between hospitals \200\224depending on demo- graphic factors, g eneral layout, access to the blood bank refrigerators, types of surgery etc. 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 647 Blood transfusion 647 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 648 Transfusion of red blood cells Used acutely in the management of \200\230significant \200\231 blood loss following trauma or surgery or electively to manage anemia which is not correctable by other means, e.g. co rrection of iron deficiency is by giving iron supple- ments, not by blood transfusion. Indications for red cell transfusion Blood loss Massive/acute Bone marrow failure Post-chemotherapy, leukaemias, etc. Supportive therapy with concentrated cells Inherited RBC disorders Homozygous b-thalassaemia Red cell aplasia, etc. Hb SS (some circumstances) Acquired RBC disorders Myelofibrosis Myelodysplasia Some chronic disorder anaemias Selected use in renal failure Neonatal & exchange transfusions Haemolytic disease of the newborn Meningococcal septicaemia Falciparum malaria RBC transfusion is contraindicated in chronic iron deficiency anemia; iron supplements will raise the hemoglobin in a safer and less costly manner. If patients are suffering marked a nemic symptoms then use of 2 units of concentrated cells will deal with this problem pendin g a response to iron. In severe megaloblastic anaemias RBCs should not be used; a rapid res ponse to haematinics is expected. Transfusion can precipitate severe cardiac failure. (cid:2) Red cells have a shelf life of 35 days at 4 C and are supplied as con- centrated red cells with PCV between 0.55 and 0.75. Most units in the UK are supplied in \200\230optimal additive solution \200\231, SAG-M*, which allows removal of all the plasma for preparation of other blood components and results in a less viscous product. The volume of a unit of concen- trated cells is 280 20mL. With adequate venous access it will flow easily through a standard blood giving set. In acute blood loss concentrated RBCs are adeq uate (whole blood not currently available in practice). Concentrated RBCs allow maintenance of oxygen delivery, and are often infused at the same time as other colloids. 648 (cid:2) (cid:2) All blood in UK is leucodepleted at source. Irradiated RBCs are indicated to stop transfusion transmitted graft versus host disease e.g . following total body irradiation, bone marrow allografting or therapy with purine analogs (fludarabine, 2-CDA). Frozen RBCs similarly have plasma and some other constituents remove d. They are expensive to process, store and handle; they must (cid:2) (cid:2) 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 649 Blood transfusion be used within 24h after thawing. Clinical usage is restricted to patients with extremely r are blood groups or with highly problematic blood group alloantibodies. In autoimmune haemolytic disorders transfusion can be lifesaving as a short term support pe nding a response to immunosuppression. As a general rule, most otherwise fit adult patients with chronic anemia will tolerate Hb levels around 9.0 \200\22310.0g/dL without major prob lems. Transfusion therapy is more likely to be needed below this level Transfusion procedure Although fussy, strictly laid down hospital protocols must be followe d for administration of blood and blood products. Errors carry the potential for major morb idity or fatality. 1. Identity of label on each matched unit must match EXACTLY with the patient \200\231s identi ty. 2. The ABO and Rh groups on the blood pack and the compatibility report must correspond as must the donor number on the pack and compatibility form. 3. Units must show no sign of leakage or damage and be used within their expiry period. 4. The prescription of blood must be made by a registered medical prac- titioner and detail s of the product \200\231s administration must be recorded in the case record. 5. An IV line should be established and flushed with 0.9% saline solution before the pack is opened. 6. No drug or other infusion solution should be added to any blood component. 7. Monitoring of the patient involves recording temperature, pulse and blood pressure befor e transfusion, every 15 min for the first hour and hourly until transfusion is finished. 8. Adverse events should be recorded meticulously. 9. Major reactions require immediate ces sation of the transfusion and instigation of a full investigative protocol (see Emergencies : Transfusion reactions, p 502 \200\223504). 10. Minor febrile reactions are not uncommon, their occurrence should be recorded, simple m easures such as slowing the rate of infusion or administration of an antihistamine may deal with the problem; if not transfusion of the specific unit should be stopped. 649 11. An RBC pack should be given within 30 min of removal from the blood bank; the target in fusion time for an individual unit should be \211 4h. 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 650 Platelet transfusion May be given as prophylaxis against bleeding e.g. in patients undergoing intensive chemothe rapy or to arrest overt hemorrhage e.g. in DIC. Platelets may be required to cover surgery and dentistry. Indications for platelet transfusion 55 production due to BM failure/infiltration Acute and chronic leukaemias Myelodysplasia Myeloproliferative disorders and myelofibrosis Marrow infiltration with other malignant tumors Post-chemotherapy or TBI Aplastic anemia 44 platelet destruction in peripheral circulation hypertension Hypersplenism 2 splenic infiltration or portal Consumptive coagulopathies e.g. DIC Avoid in TTP (p530) Acute and chronic ITP (in emergenci es only) Alloimmune thrombocytopenias e.g. PTP and perinatal thrombocytopenia (need to be H PA typed) Sepsis Drug induced Platelet function abnormalities Aspirin and NSAIDs Myelodysplasia Rare congenital disorders e.g. Bernard \200\223Soulier Dilutional Massive blood transfusion \200\224in practice not usually required unless some other haemos tatic abnormality (e.g. consumption) Cardiac bypass Dilution and damage to platelets in extracorporeal circulation. Indications for irradiated platelets Recommended in immunosuppressed patients and haemopoie tic stem cell transplant recipients to prevent transfusion-associated GvHD. Indications for CMV negative platelets 1. Where CMV transmission may cause disease. 2. BM a nd PBSCT recipients who are CMV \200\223ve. 3. Solid organ transplant recipients who are C MV \200\223ve. 4. 5. Aplastic anemia. 6. GvHD. 7. Primary immunodeficiency syndromes. 650 In utero and neonatal transfusion. 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 651 Blood transfusion 651 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 652 Fresh frozen plasma (FFP) FFP is prepared by removing plasma from a single donor unit by centrifu- gation within 8h o f donation, snap frozen at \200\22380 C and maintained deep frozen until use. Serological testing excludes HBV, HCV, HIV and the product is ABO and Rh (D) grouped. Group AB Rh (D) \200\223ve FFP is suitable for all groups since it lacks anti-A and B, and will not sensit ize Rh(D) \200\223ve patients to Rh(D). Range and median concentrations of vitamin K dependent VII Factor coagulation factors in FF P Range (u/dL) Median II IX X 53 \200\223121 82.5 41 \200\223140 92.0 32 \200\223102 61.0 61 \200\223150 90.5 Indications for use 2 Warfarin overdose \200\224see p522. 2 DIC (common causes include obst etric hemorrhage, postoperative complications, following trauma, severe infection, septicae mic shock, acute blood loss \200\224see p512). 2 Liver disease and biopsy. 2 Massive blood transfusion \200\224use of prophylactic FFP (1 \200\2232 units FFP/10 units of blood) and platelets is not supported by documented clinica l benefit. Give as dictated by coagulation tests. 2 Isolated coagulation deficiencies where no specific concentrate is readily available. 2 Treatment of thrombotic thrombocytopenia purpura/haemolytic uraemic syndrome (see p468, 530). 2 Non-specific haemostatic failure in a bleeding patient e.g. following surgery, in intensi ve care with disturbed coagulation tests where no definite diagnosis is made. Instructions for use The average volume of 1 unit is 220 \200\223250mL. Half-life of infused coagulation factors in FFP <12h >12 <24h >24 <48h >48h Factors V, VII, VIII, and protein C Factor IX and protein S Factor X Fibrinogen, factors XI , XII, XIII, ATIII 652 2 Defrost the bag in a waterbath (5 min) or at room temperature (20 min). 2 Give as soon as possible and at least within the hour through a filter needle. 2 Must be group compatible; if blood group not known, give \200\230all groups \200\231. 2 If recipient Rh (D) \200\223ve 3 of child bearing age given Rh (D) +ve plasma give anti-D (250u). 2 Dose 10 \200\22315mL/kg body wt (usual starting dose in an adult = 2 \200\2234 units depending on the PT). 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 653 Blood transfusion 2 Check PT and APTT before and 5 min after infusion to assess response. 2 Note clinical response in bleeding patients; repeat as necessary, remember short half-life. 653 Makris, M. et al. (1997) Emergency oral anticoagulant reversal: the relative efficacy of in fusions of fresh frozen plasma and clotting factor concentrates on correction of coagulopat hy. Thrombosis Haemostasis, 77 477 \200\22380. 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 654 Cryoprecipitate 2 Prepared by slow thawing of FFP at 4 \200\2236 C. Fresh plasma taken from a single donor is snap frozen then thawed at 4 C and a cryoprecipitate forms. 2 Precipitate formed is cryoprecipitate which is then stored at \200\22330 C. 2 Rich in f actors VIII, XIII, fibrinogen and von Willebrand factor. Per unit (bag): \200\223 Factor VIII and vWF 80 \200\223100iu. \200\223 Fibrinogen 250m g. \200\223 Factor XIII and fibronectin. \200\223 Does not contain other coagulation fact ors. \200\223 May contain anti-A and anti-B blood group antibodies. 2 Formerly (but no longer) used for management of bleeding in factor VIII deficiency and von Willebrand \200\231s disease. 2 Main clinical use for cryoprecipitate is as additional support for the clotting defects induced by massive transfusion and DIC. 2 All donations are screened for HIV, HBV and HCV. Indications for use 2 Hemophilia A and vWD not treatment of choice where virally inacti- va ted concentrates are available. May still have a role in acquired vWD when purified factor VIII products are ineffective. 2 Hypo/dysfibrinogenaemia e.g. in DIC and liver disease/liver transplanta- tion is used to treat and prevent bleeding. 2 Of no proven value as empirical treatment in post-op or uraemic bleeding. Instructions for use 2 Keep frozen until required. 2 Thaw at room temperature/37 C (takes 5 \200\22310 min); use immediately. 2 ABO compatibility not required. 2 Give through filter needle. 2 Dose depends on the indications for use and desired increment severe 2 \200\2234 bags/10kg body wt less severe 1 \200\2232 bags. \200\223 Hypofibrinogenaemia: 2 Aim to keep fibrinogen >1g/L. 2 Factor VIII minimum adult dose 5 bags. Complications Viral transmission \200\224rare but reported. Reactions, fever, chills, alle rgic reactions. 654 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 655 Blood transfusion 655 17-blood%2fproducts.qxd 10.12.2003 04.34 PM Page 656 Intravenous immunoglobulin Used as antibody replacement in 1 and 2 antibody deficiency states, and as immune modul ator. Preparations of intravenous IgG (IVIg) 2 Contain predominantly IgG (with small amounts of I gA and IgM). 2 Prepared from large pool of normal donors e.g. >1000. 2 Contain all subclass es of IgG encountered in normal population. Uses