sickle cell disease ( scd ) is a form of haemoglobinopathy caused by the abnormal genetic substitution of glutamine by valine in the haem portion of the haemoglobin molecule . sickle haemoglobin ( hbs ) tends to form polymers and aggregates when deoxygenated and can lead to vasoocclusion and organ ischaemia ( 1 ) . cardiopulmonary bypass ( cpb ) is commonly associated with hypothermia , hypoxia , hypoperfusion , and acidosis , which are pre - disposing factors that can trigger a profound sickle cell crisis . when such patients undergo cardiac surgery with cpb , they need special precautions and management to prevent fatal vaso - occlusive episodes . there are no guidelines for management of sickle cell patients during cardiac surgery , but only case reports are mentioned in the literature . an 11-year - old child ( weight - 23 kg , height - 122 cm , body surface area - 0.89 m ) presented with a history of shortness of breath while playing , jaundice , and joint pain . she was a known case of sickle cell anaemia with a history suggestive of sickling crisis in the past , which was managed by blood transfusion . patient was started on hydroxyurea 250 mg / day ( oral ) . on admission , haemoglobin assessment by electrophoresis revealed hbs of 70.80% and adult haemoglobin ( hba ) of 30.60% . one unit whole blood was transfused and before induction , hb electrophoresis values were obtained , which showed hbs 30.3% , foetal haemoglobin ( hbf ) 12.1% , and hba 49.9% . cardiopulmonary bypass circuit was primed with 1300 ml of ringers solution , 3 units of fresh donor red cells ( collected within 24 h ) , 1 unit fresh frozen plasma , 60 ml albumin 20% , 100 ml mannitol and 50 ml 7.5% sodium bicarbonate . after the circuit was primed , the fluid was circulated through oxygenator to achieve adequate oxygenation and warming of blood . analysis of prime fluid showed pao2 of 310 mm hg , haematocrit of 24% and potassium , 3.0 mmol / dl . after systemic heparinisation with 3 mg / kg of heparin , aortic and bicaval cannulation was performed . before the start of cpb , exchange transfusion was planned to reduce hbs level and raise hba level [ figure 1 ] . as 500 ml autologous blood was drained , systolic arterial pressure dropped to 50 mm hg . venous drainage was stopped temporarily , and prime fluid was infused until haemodynamics got stabilised . the drainage was slowly restarted , and volume of 1400 ml of autologous blood was collected with simultaneous infusion of priming fluid . after exchange transfusion , hb electrophoresis showed hbs  6.5% , hbf  3.2% , and hba  78.2% . cpb was initiated with flows at 2.3 - 2.5 l / min at normothermia [ table 1 ] . venous reservoir level was maintained by adding fresh blood to keep haematocrit level near 25% . patient was weaned from bypass by inotropic support of adrenaline 0.02 g / kg / min . as the patient was off the bypass , remaining blood in the reservoir post - cpb , patient was maintained normothermic using warm fluid , warm air mattress , and at room temperature . after heparin reversal , hb was 8.4 g / dl and one unit fresh blood was transfused . post - operative hb was 10.2 g / dl and hbs 10% [ table 2 ] . cardiopulmonary bypass circuit showing arrangements for exchange transfusion laboratory parameters in the peri - operative period sickle cell disease is an autosomal recessive condition that results from a single nucleotide polymorphism in the -globin gene . under the right conditions haemoglobin ss molecules with this point mutation can polymerise , stiffening the erythrocyte membrane and distorting the cellular structure to the characteristic sickle shape . certain circumstances such as hypoxia , hypothermia , acidosis or diminished blood flow can lead to aggregation , vascular occlusion and thrombosis . chronically , scd can give rise to multiorgan damage secondary to haemolysis and vascular obstruction . reduced life expectancy and a tendency for complications in sickle cell trait or disease can negatively affect the likelihood of survival after open heart surgery . have reported heart valve surgery and surgery for congenital heart diseases performed safely in patients with scd or sickle cell trait with acceptable outcome and survival rates . described a method of complete intraoperative exchange transfusion in the operating room that reduces the haemoglobin s ( hbs ) level to < 5% , without pre - operative exchange transfusions . plasma and platelet fractions separated intra - operatively from the patient 's native red cell mass were used , in addition to hemoconcentration while on cpb , to effectively reduce the red cell and clotting factor transfusion requirements after the procedure . suggested minimally invasive , warm , beating heart approach to try and minimise the risk of sickling due to cpb , low - flow states , cold cardioplegia and aortic cross - clamping . maddali et al . have reported case of elective coronary artery bypass graft surgery in a scd patient using cpb techniques following pre - operative transfusions to increase the haemoglobin a levels to above 60% . in this case , we used pre - operative blood transfusion and hydroxyurea . pre - operative blood transfusion is indicated in scd patients to raise the haematocrit level and lower hbs levels . hydroxyurea is the main treatment in symptomatic sickle cell patients because of its beneficial effects . hydroxyurea increases hbf , which prevents sickling and also has beneficial effects on red blood cells hydration and vascular wall adhesion . there is no consensus on safe values of hbs in patients undergoing surgery , but some reports suggest hbs should be decreased to < 30% for major surgeries or < 5% for cardiac surgeries prior or at the time of operation . in our case , even though hbs was 30.3% before surgery , we decided to do pre - operative exchange transfusion to promote perfusion , lower the incidence of peri - operative sickling crisis and perioperative multiorgan failure . exchange transfusion is known to decrease hbs , increases pre - operative hba , haematocrit , and cellular oxygen delivery . the classic pre - disposing factors for sickling include exposure to cold stress , dehydration , infections , hypoxia , inflammatory cascades , and acidosis . hypothermia is prevented by employing normothermic cpb , use of warm air blankets and maintaining operating theatre temperature . we avoided hypoxia by hyperoxygenating pump prime , maintaining haematocrit above 24% by using fresh donor blood ( collected within 24 h ) and keeping venous oxygenation saturation above 80% . frequent monitoring of arterial blood gas is needed to maintain ph in normal range . in our case , warm induction of cardioplegia with oxygenated crystalloid solution advantages of this technique are delivery of high pao2 to myocardium , improved distribution of cardioplegic solution due to decreased viscosity and flushing of hbs from the myocardium , thereby reducing the risk of localised anoxia . use of continuous haemofiltration and modified ultrafiltration reduces the inflammatory response and improves lung compliance . we did not use cell saver and autotransfusion was not done during or after the surgery . cardiac surgery constitutes major stress , especially in paediatric patients , so it is strongly recommended to give the patients adequate analgesia and sedation . thorough pre operative stabilisation of the patient with respect to hb and use of initial exchange transfusion , warm cardioplegia and maintenance of blood gases enable cpb to be conducted safely in sickle cell patients .