Dr Soheila zareifar Department of pediatric hematologyoncology Shiraz university of medical sciences Qeshm 2018 Transfusion in Sickle Cell In sickle cell disease transfusions improve blood flow by reducing the proportion of red cells capable of forming sickle hemoglobin polymer ID: 775023
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Transfusion in Sickle cell anemia
Dr. Soheila zareifarDepartment of pediatric hematology/oncologyShiraz university of medical sciencesQeshm 2018
Slide2Slide3Transfusion in Sickle Cell
In sickle cell disease transfusions improve blood flow by reducing the proportion of red cells capable of forming sickle hemoglobin polymer. This limits hemolysis and the endothelial damage that result from high proportions of sickle polymer-containing red cells. Additionally, transfusions are used to increase blood oxygen carrying capacity in sickle cell patients with severe chronic anemia or with severe anemic episodes.
Slide4Transfusion in Sickle Cell
However, transfusion carries risks, many of which are greater in individuals with SCD than in the general population. The approach to transfusion in SCD must balance these benefits and risks, both in decisions regarding when to transfuse and in the practical aspects of how transfusions are administered.Used correctly, transfusion can prevent organ damage and save the lives of sickle cell disease patients.Used unwisely, transfusion therapy can result in serious complications.
Slide5INDICATIONS FOR TRANSFUSIONS
The two primary goals of transfusion are:1. Management of severe anemia to correct the low oxygen-carrying capacity caused by severe anemia.2. Management of sudden severe illnessto improve microvascular perfusion by decreasing the proportion of sickle red cells in the circulation. In the clinical setting, transfusions are often used to address both indications.
Slide6Decision for transfusion
1. EPISODIC (EMERGENCY) TRANSFUSION2. PREPARATION FOR GENERAL ANESTHESIA3. CHRONIC TRANSFUSION THERAPY4. CHRONIC DEBILITATING PAIN5. CONTROVERSIAL/EQUIVOCAL INDICATIONS
Slide7EPISODIC (emergency)TRANSFUSIONS
Management of severe anemiaManagement of severe illness
Slide8Management of severe anemia
Most common: a. Acute splenic sequestration b. Acute hepatic sequestration c. Transient red cell aplasia episodes (Aplastic crisis ) d. Hyper hemolysis, is associated with infection e. Acute chest syndrome f. Increased hemolysis during painful crises
Slide9EPISODIC TRANSFUSIONSManagement of sudden severe illness
Transfusions to improve tissue oxygenation and perfusion are indicated in these seriously ill patients Acute chest syndrome Acute ischemic stroke SepsisAcute priapism Acute multi-organ failure syndrome Mesenteric (“girdle”) syndrome Acute intrahepatic cholestasis Pregnancy?? transfusion therapy to women who experience frequent complications during pregnancy.
Slide10Slide11EPISODIC TRANSFUSIONSManagement of sudden severe illness
Target Hb 10-11 g/dl is effective in preventing progression to acute respiratory failure in SS patients with mild ACS if it is given early in the illness and should be considered in patients with a PaO2 <90 on room air. Exchange transfusion is recommended in patients with features of severe ACS, those who fail to respond to initial simple transfusion, or patients with a higher Hb (>9 g/dl) where there is little leeway for simple transfusion.There is no evidence as to the optimal %HbS target post-exchange transfusion. In practice, a target of <30–40% is often used, but clinicians should be guided by the clinical response.
Slide12PREPARATION FOR GENERAL ANESTHESIA
A multi-institution study recently compared perioperative complications among patients with sickle cell disease undergoing major surgery (e.g. cholecystectomy). Patients were randomized to an aggressive transfusion arm (decrease hemoglobin S to below 30 percent) or to a conservative transfusion arm (hemoglobin S approximately 60 percent; hemoglobin corrected to 10 gr/dl). The control patients did not receive perioperative transfusions. Complications occurred in all groups, but were substantially more frequent in the non-transfused patients. There was no difference between the conservatively or aggressively transfused patients with respect to perioperative complications. However, alloimmunization occurred more frequently in the aggressively transfused group.
Slide13PREPARATION FOR GENERAL ANESTHESIA
The recommendation from this study is that all sickle cell disease patients undergoing major surgery be prepared in advance with transfusion to correct their anemia to a hemoglobin of approximately 10 gm/dl and hemoglobin S percent to approximately 60 percent. No standard practice guidelines have been developed for patients undergoing minor procedures or for patients with hemoglobin SC disease. The generally accepted practice is to not use preoperative transfusion therapy in healthy hemoglobin SC patients, nor for limited minor surgery in stable hemoglobin SS patients.
Slide14CHRONIC TRANSFUSION THERAPY
Indicated for several conditions in which the potential medical complications outweigh the risks of alloimmunization, infection and iron overload. The goal of these programs is to maintain the hemoglobin S at 30-50 percent, depending on the specific disorder.Transfusions are usually repeated every 3-4 weeks.
Slide15CHRONIC TRANSFUSION THERAPY
Primary and secondary stroke preventionSecondary prevention of silent cerebral infarction in children with SCDSecondary prevention of overt stroke in children with SCDPrevention of recurrence of strokeRecurrent ACSFrequent painful crises( ≥3 times a year because of vaso-occlusive crises are at increased risk of early death)Pulmonary hypertension and chronic lung diseaseVital organ failure
Slide16Primary stroke prevention
The STOP trial demonstrated that chronic transfusion therapy reduces the occurrence of first stroke in children with a rate of high blood flow through the circle of Willis cerebral arteries, as measured by Doppler ultrasonography. This was the first application of chronic transfusion therapy to prevent potential complications of sickle cell disease.
Slide17Prevention of recurrence of stroke
Chronic transfusion therapy for children who suffer vaso-occlusive stroke decreases the recurrent stroke rate from 90 percent to less than 10 percent. Initially, the hemoglobin S level is maintained at 30 percent or less for approximately 5 years. Well-controlled studies have not determined the duration or percent level of hemoglobin S required for long-term treatment of these patients. Pilot studies allowing the hemoglobin S to rise to 50 percent in patients with stable neurologic disease are on-going.
Slide18Pulmonary hypertension , chronic lung disease
Chronic transfusion therapy has been used to decrease the recurrence of pulmonary events in patients experiencing severe acute chest syndrome. While pilot data suggests this therapy is efficacious, rigorous clinical trials have not been completed. The duration of such treatment programs is also unknown. Patients with proven pulmonary hypertension and chronic lung disease should receive long-term chronic transfusion therapy.
Slide19Vital organ failure
Chronic heart failure is a late complication of sickle cell disease. Transfusion therapy for these patients, along with interventions to improve cardiac function, enhances quality of life. Severe anemia, secondary to chronic renal failure, often becomes debilitating. Erythropoietin therapy is often ineffective, leaving chronic transfusion therapy as the sole option.
Slide20CONTROVERSIAL/EQUIVOCAL INDICATIONS
Management of acute priapismPreparation for infusion of contrast mediaPregnancyManagement of "silent" cerebral infarct and/or neurocognitive damageLeg ulcers
Slide21Non-indications and contra-indications
1. Chronic steady-state anemia. 2. Uncomplicated acute painful crises.3. Infections4. Minor surgery not requiring prolonged general anesthesia (e.g., myringotomy)5. Aseptic necrosis of the hip or shoulder (except when surgery is required)6. Uncomplicated pregnancy7. Leg ulcer8. Prior to contrast media exposure9. Sub-clinical neurological damage11. Priapism
Slide22Slide23TRANSFUSION METHODS
Simple transfusion used for acute anemia or hypovolemiaExchange transfusion is used to alter the hemoglobin level rapidly and to replace sickle cells with normal cellsRapid partial exchange whole blood can be removed from one arm at the same time that donor cells are transfused into the other armErythrocytopheresis When to use each method?
Slide24Except in severe anemia, exchange transfusion offers many benefits and is our first choicePhenotypically matched, leuko - depleted packed cells are the blood product of choice. A posttransfusion hematocrit of 30 to 36 percent or less is recommended. Avoid hyper viscosity, which is dangerous to sickle cell patients.
Transfusion in Sickle Cell(exchange transfusion)
Slide25Exchange transfusion:Bleed one unit (500 ml), infuse 500 ml of salineBleed a second unit and infuse two units.Repeat. If the patient has a large blood mass, do it again.
Transfusion in Sickle Cell(exchange transfusion)
Slide26Episodic, acute transfusions to stabilize or reverse complications. Limited studies have shown that aggressive transfusion (get Hgb S < 30%) may help in sudden severe illness.May be useful before general anesthesia.
Transfusion in Sickle Cell(exchange transfusion)
Slide27EXCHANGE TRANSFUSION
In children, a practical estimate of the volume required for exchange (whole blood or packed cells reconstituted to a hematocrit of 30-40 percent) is 50-60 mL/kg.In adults, blood can be removed from the patient in 500 mL aliquots, followed by infusion of 500 mL of reconstituted blood; this may be repeated for 6-8 units of transfusion. Alternatively, the following technique can be used: Bleed one unit (500 mL) of blood from the patient, infuse 500 mL of saline.Bleed a second unit from the patient, infuse two units of blood.Repeat steps 1 and 2; if the patient has a large red blood cell mass, repeat once more.
Slide28EXCHANGE TRANSFUSION
Usually 6-8 units of blood are needed to exchange and adult. Formulae are available to calculate the exact amount needed depending on body size, pretreatment hematocrit, desired hematocrit, and desired percentage of hemoglobin A. Such devices can be used for pediatric patients if the size of the receptacle is sufficiently small so as not to remove too much blood at one time.
Slide29StrokeChronic debilitating painPulmonary hypertensionSetting of renal failure and heart failure
Transfusion in Sickle Cell(chronic transfusion therapy)
Slide30Inappropriate uses of transfusion:Chronic steady-state anemiaUncomplicated pain episodesInfectionMinor surgeryUncomplicated pregnanciesAseptic necrosis
Transfusion in Sickle Cell
Slide31Transfusion Mediated Iron Overload
While transfusion may improve disease complications, iron overload is a dreaded and inevitable consequence of ongoing transfusion therapy. Chronically transfused iron overloaded patients with SCD have significantly higher mortality than less transfused counterparts without iron overload, as well as age and race-matched normal controls.Available data suggest that SCD patients are relatively protected from iron-induced cardiac and endocrine organ damage as compared with TM patients.
Slide32Potential Factors Modifying Iron Toxicity in SCD
Relative distribution of iron loading in RES versus parenchymal cells Levels of NTBI and LPICoexisting hereditary iron loading defectsThe impact of ineffective erythropoiesis.The role of hepcidin in the pathophysiology of iron overload in SCD remains controversial.
Slide33Transfusion Mediated Iron Overload
The role of hepcidin in the pathophysiology of iron overload in SCD remains controversial. Although steady-state SCD patients do not exhibit increased hepcidin levels, transfusion acutely up regulates hepcidin mRNA expression.It is unclear whether this increased gene expression results in increased circulating hepcidin and decreased unbound iron immediately post transfusion. Nor is it known whether this transient increase in hepcidin expression is of clinical relevance.Patients with SCD suffer from recurrent infections and ongoing endothelial damage by reperfusion injury that result in a chronic-inflammatory-like state.This is evidenced by increased CRP, IFNγ, IL-1, and IL-6 in steady state and IL-6 and TNF- increase during crises.
Slide34Chelation therapy should be considered
NIH guidelines
(2008)
Italian Society of Hematology
(2008)
UK guidelines (Sickle Cell Society)
(2010)
Transfusion status
Serum ferritin
Liver iron
concentration
Cumulative transfusions of 120 cc packed RBC/kg
Steady-state level >1000 ng/mL
≥7 mg Fe/g dw
When >10 units of blood have been received
>1000 ng/mL
-
At least 20 top-up transfusions
-
≥7 mg Fe/g dw
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